Commit Graph

4918 Commits

Author SHA1 Message Date
Anand Jain 5a13f4308c Btrfs: sysfs: add pointer to access fs_info from fs_devices
adds fs_info pointer with struct btrfs_fs_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:21 +02:00
Anand Jain c73eccf75b Btrfs: introduce btrfs_get_fs_uuids to get fs_uuids
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain 2e7910d6ca Btrfs: sysfs: move super_kobj and device_dir_kobj from fs_info to btrfs_fs_devices
This patch will provide a framework and help to create attributes
from the structure btrfs_fs_devices which are available even before
fs_info is created. So by moving the parent kobject super_kobj from
fs_info to btrfs_fs_devices, it will help to create attributes
from the btrfs_fs_devices as well.

Patches on top of this patch now will be able to create the
sys/fs/btrfs/fsid kobject and attributes from btrfs_fs_devices
when devices are scanned and registered to the kernel.

Just to note, this does not change any of the existing btrfs sysfs
external kobject names and its attributes and not even the life
cycle of them. Changes are internal only. And to ensure the same,
this path has been tested with various device operations and,
checking and comparing the sysfs kobjects and attributes with
sysfs kobject and attributes with out this patch, and they remain
same.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain 00c921c23f Btrfs: sysfs: separate device kobject and its attribute creation
Separate device kobject and its attribute creation so that device
kobject can be created from the device discovery thread.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain 0dd2906f72 Btrfs: sysfs: let default_attrs be separate from the kset
As of now btrfs_attrs are provided using the default_attrs through
the kset. Separate them and create the default_attrs using the
sysfs_create_files instead. By doing this we will have the
flexibility that device discovery thread could create fsid
kobject.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain 720592157e Btrfs: sysfs: introduce function btrfs_sysfs_add_fsid() to create sysfs fsid
We need it in a seperate function so that it can be called from the
device discovery thread as well.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain 3a08f3b72a Btrfs: sysfs: rename __btrfs_sysfs_remove_one to btrfs_sysfs_remove_fsid
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:20 +02:00
Anand Jain aaf1330516 Btrfs: sysfs: reorder the kobject creations
As of now the order in which the kobjects are created
at btrfs_sysfs_add_one() is..
 fsid
 features
 unknown features (dynamic features)
 devices.

Since we would move fsid and device kobject to fs_devices
from fs_info structure, this patch will reorder in which
the kobjects are created as below.
 fsid
 devices
 features
 unknown features (dynamic features)

And hence the btrfs_sysfs_remove_one() will follow the same
in reverse order. and the device kobject destroy now can
be moved into the function __btrfs_sysfs_remove_one()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:19 +02:00
Anand Jain 4d435731f9 Btrfc: sysfs: fix, check if device_dir_kobj is init before destroy
Since the failure code in the btrfs_sysfs_add_one() can
call btrfs_sysfs_remove_one() even before device_dir_kobj
has been created we need to check if its null.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:19 +02:00
Anand Jain 8345ea31dc Btrfs: sysfs: fix, kobject pointer clean up needed after kobject release
The sysfs clean up self test like in the below code fails, since
fs_info->device_dir_kobject still points to its stale kobject.
Reseting this pointer will help to fix this.

open_ctree()
{

ret = btrfs_sysfs_add_one(fs_info);
::
+       btrfs_sysfs_remove_one(fs_info);
+       ret = btrfs_sysfs_add_one(fs_info);
+       if (ret) {
+               pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
+               goto fail_block_groups;
+       }

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:19 +02:00
Anand Jain e7e1aa9c91 Btrfs: sysfs: fix, undo sysfs device links
Theoritically need to remove the device links attributes, but since its entire device
kobject was removed, so there wasn't any issue of about it. Just do it nicely.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:19 +02:00
Anand Jain 4e51f005a2 Btrfs: sysfs: fix, fs_info kobject_unregister has init_completion() twice
kobject_unregister is to handle the release of the kobject,
its completion init is being called in btrfs_sysfs_add_one(),
so we don't have to do the same in the open_ctree() again.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:19 +02:00
Anand Jain 248d200df3 Btrfs: sysfs: fix, btrfs_release_super_kobj() should to clean up the kobject data
The following test case fails indicating that, thread tried to init an initialized object.

kernel: [232104.016513] kobject (ffff880006c1c980): tried to init an initialized object, something is seriously wrong.

btrfs_sysfs_remove_one() self test code:

open_tree()
{
 ::
        ret = btrfs_sysfs_add_one(fs_info);
	if (ret) {
              pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
                goto fail_block_groups;
        }
+       btrfs_sysfs_remove_one(fs_info);
+       ret = btrfs_sysfs_add_one(fs_info);
+       if (ret) {
+               pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
+               goto fail_block_groups;
+       }

cleaning up the unregistered kobject fixes this.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-05-27 12:27:18 +02:00
Linus Torvalds 7ce14f6ff2 Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "I fixed up a regression from 4.0 where conversion between different
  raid levels would sometimes bail out without converting.

  Filipe tracked down a race where it was possible to double allocate
  chunks on the drive.

  Mark has a fix for fiemap.  All three will get bundled off for stable
  as well"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix regression in raid level conversion
  Btrfs: fix racy system chunk allocation when setting block group ro
  btrfs: clear 'ret' in btrfs_check_shared() loop
2015-05-23 11:14:10 -07:00
Mike Snitzer 326e1dbb57 block: remove management of bi_remaining when restoring original bi_end_io
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for
non-chains") regressed all existing callers that followed this pattern:
 1) saving a bio's original bi_end_io
 2) wiring up an intermediate bi_end_io
 3) restoring the original bi_end_io from intermediate bi_end_io
 4) calling bio_endio() to execute the restored original bi_end_io

The regression was due to BIO_CHAIN only ever getting set if
bio_inc_remaining() is called.  For the above pattern it isn't set until
step 3 above (step 2 would've needed to establish BIO_CHAIN).  As such
the first bio_endio(), in step 2 above, never decremented __bi_remaining
before calling the intermediate bi_end_io -- leaving __bi_remaining with
the value 1 instead of 0.  When bio_inc_remaining() occurred during step
3 it brought it to a value of 2.  When the second bio_endio() was
called, in step 4 above, it should've called the original bi_end_io but
it didn't because there was an extra reference that wasn't dropped (due
to atomic operations being optimized away since BIO_CHAIN wasn't set
upfront).

Fix this issue by removing the __bi_remaining management complexity for
all callers that use the above pattern -- bio_chain() is the only
interface that _needs_ to be concerned with __bi_remaining.  For the
above pattern callers just expect the bi_end_io they set to get called!
Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls
that aren't associated with the bio_chain() interface.

Also, the bio_inc_remaining() interface has been moved local to bio.c.

Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:58:55 -06:00
Chris Mason 153c35b6cc Btrfs: fix regression in raid level conversion
Commit 2f0810880f changed
btrfs_set_block_group_ro to avoid trying to allocate new chunks with the
new raid profile during conversion.  This fixed failures when there was
no space on the drive to allocate a new chunk, but the metadata
reserves were sufficient to continue the conversion.

But this ended up causing a regression when the drive had plenty of
space to allocate new chunks, mostly because reduce_alloc_profile isn't
using the new raid profile.

Fixing btrfs_reduce_alloc_profile is a bigger patch.  For now, do a
partial revert of 2f0810880, and don't error out if we hit ENOSPC.

Signed-off-by: Chris Mason <clm@fb.com>
Tested-by: Dave Sterba <dsterba@suse.cz>
Reported-by: Holger Hoffstaette <holger.hoffstaette@googlemail.com>
2015-05-20 11:03:38 -07:00
Filipe Manana a96295965b Btrfs: fix racy system chunk allocation when setting block group ro
If while setting a block group read-only we end up allocating a system
chunk, through check_system_chunk(), we were not doing it while holding
the chunk mutex which is a problem if a concurrent chunk allocation is
happening, through do_chunk_alloc(), as it means both block groups can
end up using the same logical addresses and physical regions in the
device(s). So make sure we hold the chunk mutex.

Cc: stable@vger.kernel.org  # 4.0+
Fixes: 2f0810880f ("btrfs: delete chunk allocation attemp when
                      setting block group ro")

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-19 18:04:17 -07:00
Mark Fasheh 2c2ed5aa01 btrfs: clear 'ret' in btrfs_check_shared() loop
btrfs_check_shared() is leaking a return value of '1' from
find_parent_nodes(). As a result, callers (in this case, extent_fiemap())
are told extents are shared when they are not. This in turn broke fiemap on
btrfs for kernels v3.18 and up.

The fix is simple - we just have to clear 'ret' after we are done processing
the results of find_parent_nodes().

It wasn't clear to me at first what was happening with return values in
btrfs_check_shared() and find_parent_nodes() - thanks to Josef for the help
on irc. I added documentation to both functions to make things more clear
for the next hacker who might come across them.

If we could queue this up for -stable too that would be great.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-19 18:04:17 -07:00
Christoph Hellwig b25de9d6da block: remove BIO_EOPNOTSUPP
Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
to help propagating those to the buffer_head layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:17:03 -06:00
Linus Torvalds c7309e88a6 Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "The first commit is a fix from Filipe for a very old extent buffer
  reuse race that triggered a BUG_ON.  It hasn't come up often, I looked
  through old logs at FB and we hit it a handful of times over the last
  year.

  The rest are other corners he hit during testing"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix race when reusing stale extent buffers that leads to BUG_ON
  Btrfs: fix race between block group creation and their cache writeout
  Btrfs: fix panic when starting bg cache writeout after IO error
  Btrfs: fix crash after inode cache writeback failure
2015-05-16 15:50:58 -07:00
Filipe Manana 062c19e9dd Btrfs: fix race when reusing stale extent buffers that leads to BUG_ON
There's a race between releasing extent buffers that are flagged as stale
and recycling them that makes us it the following BUG_ON at
btrfs_release_extent_buffer_page:

    BUG_ON(extent_buffer_under_io(eb))

The BUG_ON is triggered because the extent buffer has the flag
EXTENT_BUFFER_DIRTY set as a consequence of having been reused and made
dirty by another concurrent task.

Here follows a sequence of steps that leads to the BUG_ON.

      CPU 0                                                    CPU 1                                                CPU 2

path->nodes[0] == eb X
X->refs == 2 (1 for the tree, 1 for the path)
btrfs_header_generation(X) == current trans id
flag EXTENT_BUFFER_DIRTY set on X

btrfs_release_path(path)
    unlocks X

                                                      reads eb X
                                                         X->refs incremented to 3
                                                      locks eb X
                                                      btrfs_del_items(X)
                                                         X becomes empty
                                                         clean_tree_block(X)
                                                             clear EXTENT_BUFFER_DIRTY from X
                                                         btrfs_del_leaf(X)
                                                             unlocks X
                                                             extent_buffer_get(X)
                                                                X->refs incremented to 4
                                                             btrfs_free_tree_block(X)
                                                                X's range is not pinned
                                                                X's range added to free
                                                                  space cache
                                                             free_extent_buffer_stale(X)
                                                                lock X->refs_lock
                                                                set EXTENT_BUFFER_STALE on X
                                                                release_extent_buffer(X)
                                                                    X->refs decremented to 3
                                                                    unlocks X->refs_lock
                                                      btrfs_release_path()
                                                         unlocks X
                                                         free_extent_buffer(X)
                                                             X->refs becomes 2

                                                                                                      __btrfs_cow_block(Y)
                                                                                                          btrfs_alloc_tree_block()
                                                                                                              btrfs_reserve_extent()
                                                                                                                  find_free_extent()
                                                                                                                      gets offset == X->start
                                                                                                              btrfs_init_new_buffer(X->start)
                                                                                                                  btrfs_find_create_tree_block(X->start)
                                                                                                                      alloc_extent_buffer(X->start)
                                                                                                                          find_extent_buffer(X->start)
                                                                                                                              finds eb X in radix tree

    free_extent_buffer(X)
        lock X->refs_lock
            test X->refs == 2
            test bit EXTENT_BUFFER_STALE is set
            test !extent_buffer_under_io(eb)

                                                                                                                              increments X->refs to 3
                                                                                                                              mark_extent_buffer_accessed(X)
                                                                                                                                  check_buffer_tree_ref(X)
                                                                                                                                    --> does nothing,
                                                                                                                                        X->refs >= 2 and
                                                                                                                                        EXTENT_BUFFER_TREE_REF
                                                                                                                                        is set in X
                                                                                                              clear EXTENT_BUFFER_STALE from X
                                                                                                              locks X
                                                                                                          btrfs_mark_buffer_dirty()
                                                                                                              set_extent_buffer_dirty(X)
                                                                                                                  check_buffer_tree_ref(X)
                                                                                                                     --> does nothing, X->refs >= 2 and
                                                                                                                         EXTENT_BUFFER_TREE_REF is set
                                                                                                                  sets EXTENT_BUFFER_DIRTY on X

            test and clear EXTENT_BUFFER_TREE_REF
            decrements X->refs to 2
        release_extent_buffer(X)
            decrements X->refs to 1
            unlock X->refs_lock

                                                                                                      unlock X
                                                                                                      free_extent_buffer(X)
                                                                                                          lock X->refs_lock
                                                                                                          release_extent_buffer(X)
                                                                                                              decrements X->refs to 0
                                                                                                              btrfs_release_extent_buffer_page(X)
                                                                                                                   BUG_ON(extent_buffer_under_io(X))
                                                                                                                       --> EXTENT_BUFFER_DIRTY set on X

Fix this by making find_extent buffer wait for any ongoing task currently
executing free_extent_buffer()/free_extent_buffer_stale() if the extent
buffer has the stale flag set.
A more clean alternative would be to always increment the extent buffer's
reference count while holding its refs_lock spinlock but find_extent_buffer
is a performance critical area and that would cause lock contention whenever
multiple tasks search for the same extent buffer concurrently.

A build server running a SLES 12 kernel (3.12 kernel + over 450 upstream
btrfs patches backported from newer kernels) was hitting this often:

[1212302.461948] kernel BUG at ../fs/btrfs/extent_io.c:4507!
(...)
[1212302.470219] CPU: 1 PID: 19259 Comm: bs_sched Not tainted 3.12.36-38-default #1
[1212302.540792] Hardware name: Supermicro PDSM4/PDSM4, BIOS 6.00 04/17/2006
[1212302.540792] task: ffff8800e07e0100 ti: ffff8800d6412000 task.ti: ffff8800d6412000
[1212302.540792] RIP: 0010:[<ffffffffa0507081>]  [<ffffffffa0507081>] btrfs_release_extent_buffer_page.constprop.51+0x101/0x110 [btrfs]
(...)
[1212302.630008] Call Trace:
[1212302.630008]  [<ffffffffa05070cd>] release_extent_buffer+0x3d/0xa0 [btrfs]
[1212302.630008]  [<ffffffffa04c2d9d>] btrfs_release_path+0x1d/0xa0 [btrfs]
[1212302.630008]  [<ffffffffa04c5c7e>] read_block_for_search.isra.33+0x13e/0x3a0 [btrfs]
[1212302.630008]  [<ffffffffa04c8094>] btrfs_search_slot+0x3f4/0xa80 [btrfs]
[1212302.630008]  [<ffffffffa04cf5d8>] lookup_inline_extent_backref+0xf8/0x630 [btrfs]
[1212302.630008]  [<ffffffffa04d13dd>] __btrfs_free_extent+0x11d/0xc40 [btrfs]
[1212302.630008]  [<ffffffffa04d64a4>] __btrfs_run_delayed_refs+0x394/0x11d0 [btrfs]
[1212302.630008]  [<ffffffffa04db379>] btrfs_run_delayed_refs.part.66+0x69/0x280 [btrfs]
[1212302.630008]  [<ffffffffa04ed2ad>] __btrfs_end_transaction+0x2ad/0x3d0 [btrfs]
[1212302.630008]  [<ffffffffa04f7505>] btrfs_evict_inode+0x4a5/0x500 [btrfs]
[1212302.630008]  [<ffffffff811b9e28>] evict+0xa8/0x190
[1212302.630008]  [<ffffffff811b0330>] do_unlinkat+0x1a0/0x2b0

I was also able to reproduce this on a 3.19 kernel, corresponding to Chris'
integration branch from about a month ago, running the following stress
test on a qemu/kvm guest (with 4 virtual cpus and 16Gb of ram):

  while true; do
     mkfs.btrfs -l 4096 -f -b `expr 20 \* 1024 \* 1024 \* 1024` /dev/sdd
     mount /dev/sdd /mnt
     snapshot_cmd="btrfs subvolume snapshot -r /mnt"
     snapshot_cmd="$snapshot_cmd /mnt/snap_\`date +'%H_%M_%S_%N'\`"
     fsstress -d /mnt -n 25000 -p 8 -x "$snapshot_cmd" -X 100
     umount /mnt
  done

Which usually triggers the BUG_ON within less than 24 hours:

[49558.618097] ------------[ cut here ]------------
[49558.619732] kernel BUG at fs/btrfs/extent_io.c:4551!
(...)
[49558.620031] CPU: 3 PID: 23908 Comm: fsstress Tainted: G        W      3.19.0-btrfs-next-7+ #3
[49558.620031] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[49558.620031] task: ffff8800319fc0d0 ti: ffff880220da8000 task.ti: ffff880220da8000
[49558.620031] RIP: 0010:[<ffffffffa0476b1a>]  [<ffffffffa0476b1a>] btrfs_release_extent_buffer_page+0x20/0xe9 [btrfs]
(...)
[49558.620031] Call Trace:
[49558.620031]  [<ffffffffa0476c73>] release_extent_buffer+0x90/0xd3 [btrfs]
[49558.620031]  [<ffffffff8142b10c>] ? _raw_spin_lock+0x3b/0x43
[49558.620031]  [<ffffffffa0477052>] ? free_extent_buffer+0x37/0x94 [btrfs]
[49558.620031]  [<ffffffffa04770ab>] free_extent_buffer+0x90/0x94 [btrfs]
[49558.620031]  [<ffffffffa04396d5>] btrfs_release_path+0x4a/0x69 [btrfs]
[49558.620031]  [<ffffffffa0444907>] __btrfs_free_extent+0x778/0x80c [btrfs]
[49558.620031]  [<ffffffffa044a485>] __btrfs_run_delayed_refs+0xad2/0xc62 [btrfs]
[49558.728054]  [<ffffffff811420d5>] ? kmemleak_alloc_recursive.constprop.52+0x16/0x18
[49558.728054]  [<ffffffffa044c1e8>] btrfs_run_delayed_refs+0x6d/0x1ba [btrfs]
[49558.728054]  [<ffffffffa045917f>] ? join_transaction.isra.9+0xb9/0x36b [btrfs]
[49558.728054]  [<ffffffffa045a75c>] btrfs_commit_transaction+0x4c/0x981 [btrfs]
[49558.728054]  [<ffffffffa0434f86>] btrfs_sync_fs+0xd5/0x10d [btrfs]
[49558.728054]  [<ffffffff81155923>] ? iterate_supers+0x60/0xc4
[49558.728054]  [<ffffffff8117966a>] ? do_sync_work+0x91/0x91
[49558.728054]  [<ffffffff8117968a>] sync_fs_one_sb+0x20/0x22
[49558.728054]  [<ffffffff81155939>] iterate_supers+0x76/0xc4
[49558.728054]  [<ffffffff811798e8>] sys_sync+0x55/0x83
[49558.728054]  [<ffffffff8142bbd2>] system_call_fastpath+0x12/0x17

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11 07:59:11 -07:00
Filipe Manana ff1f8250a9 Btrfs: fix race between block group creation and their cache writeout
So creating a block group has 2 distinct phases:

Phase 1 - creates the btrfs_block_group_cache item and adds it to the
rbtree fs_info->block_group_cache_tree and to the corresponding list
space_info->block_groups[];

Phase 2 - adds the block group item to the extent tree and corresponding
items to the chunk tree.

The first phase adds the block_group_cache_item to a list of pending block
groups in the transaction handle, and phase 2 happens when
btrfs_end_transaction() is called against the transaction handle.

It happens that once phase 1 completes, other concurrent tasks that use
their own transaction handle, but points to the same running transaction
(struct btrfs_trans_handle->transaction), can use this block group for
space allocations and therefore mark it dirty. Dirty block groups are
tracked in a list belonging to the currently running transaction (struct
btrfs_transaction) and not in the transaction handle (btrfs_trans_handle).

This is a problem because once a task calls btrfs_commit_transaction(),
it calls btrfs_start_dirty_block_groups() which will see all dirty block
groups and attempt to start their writeout, including those that are
still attached to the transaction handle of some concurrent task that
hasn't called btrfs_end_transaction() yet - which means those block
groups haven't gone through phase 2 yet and therefore when
write_one_cache_group() is called, it won't find the block group items
in the extent tree and abort the current transaction with -ENOENT,
turning the fs into readonly mode and require a remount.

Fix this by ignoring -ENOENT when looking for block group items in the
extent tree when we attempt to start the writeout of the block group
caches outside the critical section of the transaction commit. We will
try again later during the critical section and if there we still don't
find the block group item in the extent tree, we then abort the current
transaction.

This issue happened twice, once while running fstests btrfs/067 and once
for btrfs/078, which produced the following trace:

[ 3278.703014] WARNING: CPU: 7 PID: 18499 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[ 3278.707329] BTRFS: Transaction aborted (error -2)
(...)
[ 3278.731555] Call Trace:
[ 3278.732396]  [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[ 3278.733860]  [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[ 3278.735312]  [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[ 3278.736874]  [<ffffffffa03ada6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[ 3278.738302]  [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[ 3278.739520]  [<ffffffffa03ada6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[ 3278.741222]  [<ffffffffa03b9e56>] write_one_cache_group+0xae/0xbf [btrfs]
[ 3278.742797]  [<ffffffffa03c487b>] btrfs_start_dirty_block_groups+0x170/0x2b2 [btrfs]
[ 3278.744492]  [<ffffffffa03d309c>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
[ 3278.746084]  [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[ 3278.747249]  [<ffffffffa03e5660>] btrfs_sync_file+0x313/0x387 [btrfs]
[ 3278.748744]  [<ffffffff8117acad>] vfs_fsync_range+0x95/0xa4
[ 3278.749958]  [<ffffffff81435b54>] ? ret_from_sys_call+0x1d/0x58
[ 3278.751218]  [<ffffffff8117acd8>] vfs_fsync+0x1c/0x1e
[ 3278.754197]  [<ffffffff8117ae54>] do_fsync+0x34/0x4e
[ 3278.755192]  [<ffffffff8117b07c>] SyS_fsync+0x10/0x14
[ 3278.756236]  [<ffffffff81435b32>] system_call_fastpath+0x12/0x17
[ 3278.757366] ---[ end trace 9a4d4df4969709aa ]---

Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout
                      outside critical section in commit")

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11 07:59:10 -07:00
Filipe Manana 28aeeac1dd Btrfs: fix panic when starting bg cache writeout after IO error
When waiting for the writeback of block group cache we returned
immediately if there was an error during writeback without waiting
for the ordered extent to complete. This left a short time window
where if some other task attempts to start the writeout for the same
block group cache it can attempt to add a new ordered extent, starting
at the same offset (0) before the previous one is removed from the
ordered tree, causing an ordered tree panic (calls BUG()).

This normally doesn't happen in other write paths, such as buffered
writes or direct IO writes for regular files, since before marking
page ranges dirty we lock the ranges and wait for any ordered extents
within the range to complete first.

Fix this by making btrfs_wait_ordered_range() not return immediately
if it gets an error from the writeback, waiting for all ordered extents
to complete first.

This issue happened often when running the fstest btrfs/088 and it's
easy to trigger it by running in a loop until the panic happens:

  for ((i = 1; i <= 10000; i++)) do ./check btrfs/088 ; done

[17156.862573] BTRFS critical (device sdc): panic in ordered_data_tree_panic:70: Inconsistency in ordered tree at offset 0 (errno=-17 Object already exists)
[17156.864052] ------------[ cut here ]------------
[17156.864052] kernel BUG at fs/btrfs/ordered-data.c:70!
(...)
[17156.864052] Call Trace:
[17156.864052]  [<ffffffffa03876e3>] btrfs_add_ordered_extent+0x12/0x14 [btrfs]
[17156.864052]  [<ffffffffa03787e2>] run_delalloc_nocow+0x5bf/0x747 [btrfs]
[17156.864052]  [<ffffffffa03789ff>] run_delalloc_range+0x95/0x353 [btrfs]
[17156.864052]  [<ffffffffa038b7fe>] writepage_delalloc.isra.16+0xb9/0x13f [btrfs]
[17156.864052]  [<ffffffffa038d75b>] __extent_writepage+0x129/0x1f7 [btrfs]
[17156.864052]  [<ffffffffa038da5a>] extent_write_cache_pages.isra.15.constprop.28+0x231/0x2f4 [btrfs]
[17156.864052]  [<ffffffff810ad2af>] ? __module_text_address+0x12/0x59
[17156.864052]  [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[17156.864052]  [<ffffffffa038df76>] extent_writepages+0x4b/0x5c [btrfs]
[17156.864052]  [<ffffffff81144431>] ? kmem_cache_free+0x9b/0xce
[17156.864052]  [<ffffffffa0376a46>] ? btrfs_submit_direct+0x3fc/0x3fc [btrfs]
[17156.864052]  [<ffffffffa0389cd6>] ? free_extent_state+0x8c/0xc1 [btrfs]
[17156.864052]  [<ffffffffa0374871>] btrfs_writepages+0x28/0x2a [btrfs]
[17156.864052]  [<ffffffff8110c4c8>] do_writepages+0x23/0x2c
[17156.864052]  [<ffffffff81102f36>] __filemap_fdatawrite_range+0x5a/0x61
[17156.864052]  [<ffffffff81102f6e>] filemap_fdatawrite_range+0x13/0x15
[17156.864052]  [<ffffffffa0383ef7>] btrfs_fdatawrite_range+0x21/0x48 [btrfs]
[17156.864052]  [<ffffffffa03ab89e>] __btrfs_write_out_cache.isra.14+0x2d9/0x3a7 [btrfs]
[17156.864052]  [<ffffffffa03ac1ab>] ? btrfs_write_out_cache+0x41/0xdc [btrfs]
[17156.864052]  [<ffffffffa03ac1fd>] btrfs_write_out_cache+0x93/0xdc [btrfs]
[17156.864052]  [<ffffffffa0363847>] ? btrfs_start_dirty_block_groups+0x13a/0x2b2 [btrfs]
[17156.864052]  [<ffffffffa03638e6>] btrfs_start_dirty_block_groups+0x1d9/0x2b2 [btrfs]
[17156.864052]  [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[17156.864052]  [<ffffffffa037209e>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
[17156.864052]  [<ffffffffa034c748>] btrfs_sync_fs+0xe1/0x12d [btrfs]

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11 07:59:10 -07:00
Filipe Manana e43699d4b4 Btrfs: fix crash after inode cache writeback failure
If the writeback of an inode cache failed we were unnecessarilly
attempting to release again the delalloc metadata that we previously
reserved. However attempting to do this a second time triggers an
assertion at drop_outstanding_extent() because we have no more
outstanding extents for our inode cache's inode. If we were able
to start writeback of the cache the reserved metadata space is
released at btrfs_finished_ordered_io(), even if an error happens
during writeback.

So make sure we don't repeat the metadata space release if writeback
started for our inode cache.

This issue was trivial to reproduce by running the fstest btrfs/088
with "-o inode_cache", which triggered the assertion leading to a
BUG() call and requiring a reboot in order to run the remaining
fstests. Trace produced by btrfs/088:

[255289.385904] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5276
[255289.388094] ------------[ cut here ]------------
[255289.389184] kernel BUG at fs/btrfs/ctree.h:4057!
[255289.390125] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
(...)
[255289.392068] Call Trace:
[255289.392068]  [<ffffffffa035e774>] drop_outstanding_extent+0x3d/0x6d [btrfs]
[255289.392068]  [<ffffffffa0364988>] btrfs_delalloc_release_metadata+0x54/0xe3 [btrfs]
[255289.392068]  [<ffffffffa03b4174>] btrfs_write_out_ino_cache+0x95/0xad [btrfs]
[255289.392068]  [<ffffffffa036f5c4>] btrfs_save_ino_cache+0x275/0x2dc [btrfs]
[255289.392068]  [<ffffffffa03e2d83>] commit_fs_roots.isra.12+0xaa/0x137 [btrfs]
[255289.392068]  [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[255289.392068]  [<ffffffffa037841f>] ? btrfs_commit_transaction+0x4b1/0x9c9 [btrfs]
[255289.392068]  [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46
[255289.392068]  [<ffffffffa037842e>] btrfs_commit_transaction+0x4c0/0x9c9 [btrfs]
(...)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11 07:59:10 -07:00
Linus Torvalds af6472881a Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "When an arm user reported crashes near page_address(page) in my new
  code, it became clear that I can't be trusted with GFP masks.  Filipe
  beat me to the patch, and I'll just be in the corner with my dunce cap
  on"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong mapping flags for free space inode
2015-05-08 20:59:02 -07:00
Filipe Manana 1d3c61c2eb Btrfs: fix wrong mapping flags for free space inode
We were passing a flags value that differed from the intention in commit
2b10826800 ("Btrfs: don't use highmem for free space cache pages").

This caused problems in a ARM machine, leaving btrfs unusable there.

Reported-by: Merlijn Wajer <merlijn@wizzup.org>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-06 17:06:13 -07:00
Jens Axboe dac56212e8 bio: skip atomic inc/dec of ->bi_cnt for most use cases
Struct bio has a reference count that controls when it can be freed.
Most uses cases is allocating the bio, which then returns with a
single reference to it, doing IO, and then dropping that single
reference. We can remove this atomic_dec_and_test() in the completion
path, if nobody else is holding a reference to the bio.

If someone does call bio_get() on the bio, then we flag the bio as
now having valid count and that we must properly honor the reference
count when it's being put.

Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:32:49 -06:00
Linus Torvalds 64887b6882 Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "A few more btrfs fixes.

  These range from corners Filipe found in the new free space cache
  writeback to a grab bag of fixes from the list"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: btrfs_release_extent_buffer_page didn't free pages of dummy extent
  Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.
  btrfs: unlock i_mutex after attempting to delete subvolume during send
  btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache
  btrfs: fix race on ENOMEM in alloc_extent_buffer
  btrfs: handle ENOMEM in btrfs_alloc_tree_block
  Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
  Btrfs: don't check for delalloc_bytes in cache_save_setup
  Btrfs: fix deadlock when starting writeback of bg caches
  Btrfs: fix race between start dirty bg cache writeout and bg deletion
2015-05-01 07:46:21 -07:00
Forrest Liu 5d2361db48 Btrfs: btrfs_release_extent_buffer_page didn't free pages of dummy extent
btrfs_release_extent_buffer_page() can't handle dummy extent that
allocated by btrfs_clone_extent_buffer() properly. That is because
reference count of pages that allocated by btrfs_clone_extent_buffer()
was 2, 1 by alloc_page(), and another by attach_extent_buffer_page().

Running following command repeatly can check this memory leak problem

    btrfs inspect-internal inode-resolve 256 /mnt/btrfs

Signed-off-by: Chien-Kuan Yeh <ckya@synology.com>
Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-29 13:22:09 -07:00
Linus Torvalds f583381f50 Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Filipe hit two problems in my block group cache patches.  We finalized
  the fixes last week and ran through more tests"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: prevent list corruption during free space cache processing
  Btrfs: fix inode cache writeout
2015-04-26 17:40:30 -07:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Yang Dongsheng 6e17d30bfa Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.
We need to fill inode when we found a node for it in delayed_nodes_tree.
But we did not fill the ->last_trans currently, it will cause the test
of xfstest/generic/311 fail. Scenario of the 311 is shown as below:

Problem:
	(1). test_fd = open(fname, O_RDWR|O_DIRECT)
	(2). pwrite(test_fd, buf, 4096, 0)
	(3). close(test_fd)
	(4). drop_all_caches()	<-------- "echo 3 > /proc/sys/vm/drop_caches"
	(5). test_fd = open(fname, O_RDWR|O_DIRECT)
	(6). fsync(test_fd);
				<-------- we did not get the correct log entry for the file
Reason:
	When we re-open this file in (5), we would find a node
in delayed_nodes_tree and fill the inode we are lookup with the
information. But the ->last_trans is not filled, then the fsync()
will check the ->last_trans and found it's 0 then say this inode
is already in our tree which is commited, not recording the extents
for it.

Fix:
	This patch fill the ->last_trans properly and set the
runtime_flags if needed in this situation. Then we can get the
log entries we expected after (6) and generic/311 passed.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:27:03 -07:00
Omar Sandoval 909e26dce3 btrfs: unlock i_mutex after attempting to delete subvolume during send
Whenever the check for a send in progress introduced in commit
521e0546c9 (btrfs: protect snapshots from deleting during send) is
hit, we return without unlocking inode->i_mutex. This is easy to see
with lockdep enabled:

[  +0.000059] ================================================
[  +0.000028] [ BUG: lock held when returning to user space! ]
[  +0.000029] 4.0.0-rc5-00096-g3c435c1 #93 Not tainted
[  +0.000026] ------------------------------------------------
[  +0.000029] btrfs/211 is leaving the kernel with locks still held!
[  +0.000029] 1 lock held by btrfs/211:
[  +0.000023]  #0:  (&type->i_mutex_dir_key){+.+.+.}, at: [<ffffffff8135b8df>] btrfs_ioctl_snap_destroy+0x2df/0x7a0

Make sure we unlock it in the error path.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:27:02 -07:00
Omar Sandoval b86054540e btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache
If io_ctl_prepare_pages fails, the pages in io_ctl.pages are not valid.
When we try to access them later, things will blow up in various ways.

Also fix the comment about the return value, which is an errno on error,
not -1, and update the cases where it was not.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:27:01 -07:00
Omar Sandoval 5ca64f45e9 btrfs: fix race on ENOMEM in alloc_extent_buffer
Consider the following interleaving of overlapping calls to
alloc_extent_buffer:

Call 1:

- Successfully allocates a few pages with find_or_create_page
- find_or_create_page fails, goto free_eb
- Unlocks the allocated pages

Call 2:
- Calls find_or_create_page and gets a page in call 1's extent_buffer
- Finds that the page is already associated with an extent_buffer
- Grabs a reference to the half-written extent_buffer and calls
  mark_extent_buffer_accessed on it

mark_extent_buffer_accessed will then try to call mark_page_accessed on
a null page and panic.

The fix is to decrement the reference count on the half-written
extent_buffer before unlocking the pages so call 2 won't use it. We
should also set exists = NULL in the case that we don't use exists to
avoid accidentally returning a freed extent_buffer in an error case.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:27:00 -07:00
Omar Sandoval 67b7859e9b btrfs: handle ENOMEM in btrfs_alloc_tree_block
This is one of the first places to give out when memory is tight. Handle
it properly rather than with a BUG_ON.

Also fix the comment about the return value, which is an ERR_PTR, not
NULL, on error.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:27:00 -07:00
Forrest Liu 1b98450816 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
If device tree has hole, find_free_dev_extent() cannot find available
address properly.

The problem can be reproduce by following script.

    mntpath=/btrfs
    loopdev=/dev/loop0
    filepath=/home/forrest/image

    umount $mntpath
    losetup -d $loopdev
    truncate --size 100g $filepath
    losetup $loopdev $filepath
    mkfs.btrfs -f $loopdev
    mount $loopdev $mntpath

    # make device tree with one big hole
    for i in `seq 1 1 100`; do
        fallocate -l 1g $mntpath/$i
    done
    sync
    for i in `seq 1 1 95`; do
        rm $mntpath/$i
    done
    sync

    # wait cleaner thread remove unused block group
    sleep 300

    fallocate -l 1g $mntpath/aaa

    # failed to allocate new chunk
    fallocate -l 1g $mntpath/bbb

Above script will make device tree with one big hole, and can only allocate
just one chunk in a transaction, so failed to allocate new chunk for $mntpath/bbb

    item 8 key (1 DEV_EXTENT 2185232384) itemoff 15859 itemsize 48
        dev extent chunk_tree 3
        chunk objectid 256 chunk offset 106292051968 length 1073741824
    item 9 key (1 DEV_EXTENT 104190705664) itemoff 15811 itemsize 48
        dev extent chunk_tree 3
        chunk objectid 256 chunk offset 103108575232 length 1073741824

Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:26:59 -07:00
Chris Mason e4c88f007b Btrfs: don't check for delalloc_bytes in cache_save_setup
Now that we're doing free space cache writeback outside the critical
section in the commit, there is a bigger window for delalloc_bytes to
be added after a cache has been written.  find_free_extent may do this
without putting the block group back into the dirty list, and also
without a transaction running.

Checking for delalloc_bytes in cache_save_setup means we might leave the
cache marked as written without invalidating it.  Consistency checks
during mount will toss the cache, but it's better to get rid of the
check in cache_save_setup and let it get invalidated by the checks
already done during cache write out.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:26:58 -07:00
Filipe Manana 24b89d08ef Btrfs: fix deadlock when starting writeback of bg caches
While starting the writes of the dirty block group caches, if we don't
find a block group item in the extent tree we were leaving without
releasing our path, running delayed references and then looping again to
process any new dirty block groups. However this second iteration of the
loop could cause a deadlock because it tries to lock some other extent
tree node/leaf which another task already locked and it's blocked because
it's waiting for a lock on some node/leaf that is in our path that was not
released before.
We could also deadlock when running the delayed references - as we could
end up trying to lock the same nodes/leafs that we have in our local path
(with a different lock type).

Got into such case when running xfstests:

[20892.242791] ------------[ cut here ]------------
[20892.243776] WARNING: CPU: 0 PID: 13299 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[20892.245874] BTRFS: Transaction aborted (error -2)
(...)
[20892.269378] Call Trace:
[20892.269915]  [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.271097]  [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.272173]  [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.273386]  [<ffffffffa0509a6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.274857]  [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[20892.275851]  [<ffffffffa0509a6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.277341]  [<ffffffffa0515e10>] write_one_cache_group+0x68/0xaf [btrfs]
[20892.278628]  [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.280191]  [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
(...)
[20892.291316] ---[ end trace 597f77e664245373 ]---
[20892.293955] BTRFS: error (device sdg) in write_one_cache_group:3184: errno=-2 No such entry
[20892.297390] BTRFS info (device sdg): forced readonly
[20892.298222] ------------[ cut here ]------------
[20892.299190] WARNING: CPU: 0 PID: 13299 at fs/btrfs/ctree.c:2683 btrfs_search_slot+0x7e/0x7d2 [btrfs]()
(...)
[20892.326253] Call Trace:
[20892.326904]  [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.329503]  [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.330815]  [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.332556]  [<ffffffffa0510b73>] ? btrfs_search_slot+0x7e/0x7d2 [btrfs]
[20892.333955]  [<ffffffff81045f62>] warn_slowpath_null+0x1a/0x1c
[20892.335562]  [<ffffffffa0510b73>] btrfs_search_slot+0x7e/0x7d2 [btrfs]
[20892.336849]  [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc
[20892.338222]  [<ffffffffa051ad52>] ? cache_save_setup+0x43/0x2a5 [btrfs]
[20892.339823]  [<ffffffffa051ad66>] ? cache_save_setup+0x57/0x2a5 [btrfs]
[20892.341275]  [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46
[20892.342810]  [<ffffffffa0515de7>] write_one_cache_group+0x3f/0xaf [btrfs]
[20892.344184]  [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.347162]  [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
(...)
[20892.361015] ---[ end trace 597f77e664245374 ]---
[21120.688097] INFO: task kworker/u8:17:29854 blocked for more than 120 seconds.
[21120.689881]       Tainted: G        W       4.0.0-rc5-btrfs-next-9+ #2
[21120.691384] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.703696] Call Trace:
[21120.704310]  [<ffffffff8143107e>] schedule+0x74/0x83
[21120.705490]  [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs]
[21120.706757]  [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.708156]  [<ffffffffa054ac1e>] lock_extent_buffer_for_io+0x3e/0x194 [btrfs]
[21120.709892]  [<ffffffffa054bb86>] ? btree_write_cache_pages+0x273/0x385 [btrfs]
[21120.711605]  [<ffffffffa054bc42>] btree_write_cache_pages+0x32f/0x385 [btrfs]
[21120.723440]  [<ffffffffa0527552>] btree_writepages+0x23/0x5c [btrfs]
[21120.724943]  [<ffffffff8110c4c8>] do_writepages+0x23/0x2c
[21120.726008]  [<ffffffff81176dde>] __writeback_single_inode+0x73/0x2fa
[21120.727230]  [<ffffffff8117714a>] ? writeback_sb_inodes+0xe5/0x38b
[21120.728526]  [<ffffffff811771fb>] ? writeback_sb_inodes+0x196/0x38b
[21120.729701]  [<ffffffff8117726a>] writeback_sb_inodes+0x205/0x38b
(...)
[21120.747853] INFO: task btrfs:13282 blocked for more than 120 seconds.
[21120.749459]       Tainted: G        W       4.0.0-rc5-btrfs-next-9+ #2
[21120.751137] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.768457] Call Trace:
[21120.769039]  [<ffffffff8143107e>] schedule+0x74/0x83
[21120.770107]  [<ffffffffa052f25c>] btrfs_commit_transaction+0x315/0x9c9 [btrfs]
[21120.771558]  [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.773659]  [<ffffffffa056fd8c>] prepare_to_relocate+0xcb/0xd2 [btrfs]
[21120.776257]  [<ffffffffa05741da>] relocate_block_group+0x44/0x4a9 [btrfs]
[21120.777755]  [<ffffffffa05747a0>] ? btrfs_relocate_block_group+0x161/0x288 [btrfs]
[21120.779459]  [<ffffffffa05747a8>] btrfs_relocate_block_group+0x169/0x288 [btrfs]
[21120.781153]  [<ffffffffa0550403>] btrfs_relocate_chunk.isra.29+0x3e/0xa7 [btrfs]
[21120.783918]  [<ffffffffa05518fd>] btrfs_balance+0xaa4/0xc52 [btrfs]
[21120.785436]  [<ffffffff8114306e>] ? cpu_cache_get.isra.39+0xe/0x1f
[21120.786434]  [<ffffffffa0559252>] btrfs_ioctl_balance+0x23f/0x2b0 [btrfs]
(...)
[21120.889251] INFO: task fsstress:13288 blocked for more than 120 seconds.
[21120.890526]       Tainted: G        W       4.0.0-rc5-btrfs-next-9+ #2
[21120.891773] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
(...)
[21120.899960] Call Trace:
[21120.900743]  [<ffffffff8143107e>] schedule+0x74/0x83
[21120.903004]  [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs]
[21120.904383]  [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31
[21120.905608]  [<ffffffffa051125b>] btrfs_search_slot+0x766/0x7d2 [btrfs]
[21120.906812]  [<ffffffff8114290e>] ? virt_to_head_page+0x9/0x2c
[21120.907874]  [<ffffffff81144b7f>] ? cache_alloc_debugcheck_after.isra.42+0x16c/0x1cb
[21120.909551]  [<ffffffffa05124e0>] btrfs_insert_empty_items+0x5d/0xa8 [btrfs]
[21120.910914]  [<ffffffffa0512585>] btrfs_insert_item+0x5a/0xa5 [btrfs]
[21120.912181]  [<ffffffffa0520271>] ? btrfs_create_pending_block_groups+0x96/0x130 [btrfs]
[21120.913784]  [<ffffffffa052028a>] btrfs_create_pending_block_groups+0xaf/0x130 [btrfs]
[21120.915374]  [<ffffffffa052ffc2>] __btrfs_end_transaction+0x84/0x366 [btrfs]
[21120.916735]  [<ffffffffa05302b4>] btrfs_end_transaction+0x10/0x12 [btrfs]
[21120.917996]  [<ffffffffa051ab26>] btrfs_check_data_free_space+0x11f/0x27c [btrfs]
[21120.919478]  [<ffffffffa051ba25>] btrfs_delalloc_reserve_space+0x1e/0x51 [btrfs]
[21120.921226]  [<ffffffffa05382f2>] btrfs_truncate_page+0x85/0x2c4 [btrfs]
[21120.923121]  [<ffffffffa0538572>] btrfs_cont_expand+0x41/0x3ef [btrfs]
[21120.924449]  [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs]
[21120.926602]  [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc
[21120.927769]  [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs]
[21120.929324]  [<ffffffffa05410a0>] ? btrfs_file_write_iter+0x1a9/0x431 [btrfs]
[21120.930723]  [<ffffffffa05410d9>] btrfs_file_write_iter+0x1e2/0x431 [btrfs]
[21120.931897]  [<ffffffff81067d85>] ? get_parent_ip+0xe/0x3e
[21120.934446]  [<ffffffff811534c3>] new_sync_write+0x7c/0xa0
[21120.935528]  [<ffffffff81153b58>] vfs_write+0xb2/0x117
(...)

Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout
                      outside critical section in commit")

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:26:37 -07:00
Filipe Manana b58d1a9ef9 Btrfs: fix race between start dirty bg cache writeout and bg deletion
While running xfstests I ran into the following:

[20892.242791] ------------[ cut here ]------------
[20892.243776] WARNING: CPU: 0 PID: 13299 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
[20892.245874] BTRFS: Transaction aborted (error -2)
[20892.247329] Modules linked in: btrfs dm_snapshot dm_bufio dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse$
[20892.258488] CPU: 0 PID: 13299 Comm: fsstress Tainted: G        W       4.0.0-rc5-btrfs-next-9+ #2
[20892.262011] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[20892.264738]  0000000000000009 ffff880427f8bc18 ffffffff8142fa46 ffffffff8108b6a2
[20892.266244]  ffff880427f8bc68 ffff880427f8bc58 ffffffff81045ea5 ffff880427f8bc48
[20892.267761]  ffffffffa0509a6d 00000000fffffffe ffff8803545d6f40 ffffffffa05a15a0
[20892.269378] Call Trace:
[20892.269915]  [<ffffffff8142fa46>] dump_stack+0x4f/0x7b
[20892.271097]  [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad
[20892.272173]  [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb
[20892.273386]  [<ffffffffa0509a6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.274857]  [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48
[20892.275851]  [<ffffffffa0509a6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[20892.277341]  [<ffffffffa0515e10>] write_one_cache_group+0x68/0xaf [btrfs]
[20892.278628]  [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs]
[20892.280191]  [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs]
[20892.281781]  [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf
[20892.282873]  [<ffffffffa054163b>] btrfs_sync_file+0x313/0x387 [btrfs]
[20892.284111]  [<ffffffff8117acad>] vfs_fsync_range+0x95/0xa4
[20892.285203]  [<ffffffff810e603f>] ? time_hardirqs_on+0x15/0x28
[20892.286290]  [<ffffffff8123960b>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[20892.287469]  [<ffffffff8117acd8>] vfs_fsync+0x1c/0x1e
[20892.288412]  [<ffffffff8117ae54>] do_fsync+0x34/0x4e
[20892.289348]  [<ffffffff8117b07c>] SyS_fsync+0x10/0x14
[20892.290255]  [<ffffffff81435b32>] system_call_fastpath+0x12/0x17
[20892.291316] ---[ end trace 597f77e664245373 ]---
[20892.293955] BTRFS: error (device sdg) in write_one_cache_group:3184: errno=-2 No such entry
[20892.297390] BTRFS info (device sdg): forced readonly

This happens because in btrfs_start_dirty_block_groups() we splice the
transaction's list of dirty block groups into a local list and then we
keep extracting the first element of the list without holding the
cache_write_mutex mutex. This means that before we acquire that mutex
the first block group on the list might be removed by a conurrent task
running btrfs_remove_block_group(). So make sure we extract the first
element (and test the list emptyness) while holding that mutex.

Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout
                      outside critical section in commit")

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:26:37 -07:00
Jens Axboe fe0f07d08e direct-io: only inc/dec inode->i_dio_count for file systems
do_blockdev_direct_IO() increments and decrements the inode
->i_dio_count for each IO operation. It does this to protect against
truncate of a file. Block devices don't need this sort of protection.

For a capable multiqueue setup, this atomic int is the only shared
state between applications accessing the device for O_DIRECT, and it
presents a scaling wall for that. In my testing, as much as 30% of
system time is spent incrementing and decrementing this value. A mixed
read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with
better latencies too. Before:

clat percentiles (usec):
 |  1.00th=[   33],  5.00th=[   34], 10.00th=[   34], 20.00th=[   34],
 | 30.00th=[   34], 40.00th=[   34], 50.00th=[   35], 60.00th=[   35],
 | 70.00th=[   35], 80.00th=[   35], 90.00th=[   37], 95.00th=[   80],
 | 99.00th=[   98], 99.50th=[  151], 99.90th=[  155], 99.95th=[  155],
 | 99.99th=[  165]

After:

clat percentiles (usec):
 |  1.00th=[   95],  5.00th=[  108], 10.00th=[  129], 20.00th=[  149],
 | 30.00th=[  155], 40.00th=[  161], 50.00th=[  167], 60.00th=[  171],
 | 70.00th=[  177], 80.00th=[  185], 90.00th=[  201], 95.00th=[  270],
 | 99.00th=[  390], 99.50th=[  398], 99.90th=[  418], 99.95th=[  422],
 | 99.99th=[  438]

In other setups, Robert Elliott reported seeing good performance
improvements:

https://lkml.org/lkml/2015/4/3/557

The more applications accessing the device, the worse it gets.

Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells
do_blockdev_direct_IO() that it need not worry about incrementing
or decrementing the inode i_dio_count for this caller.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Elliott, Robert (Server Storage) <elliott@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-24 15:45:28 -04:00
Chris Mason a3bdccc4e6 Btrfs: prevent list corruption during free space cache processing
__btrfs_write_out_cache is holding the ctl->tree_lock while it prepares
a list of bitmaps to record in the free space cache.  It was dropping
the lock while it worked on other components, which made a window for
free_bitmap() to free the bitmap struct without removing it from the
list.

This changes things to hold the lock the whole time, and also makes sure
we hold the lock during enospc cleanup.

Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-24 11:52:25 -07:00
Linus Torvalds ba0e4ae88f Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "I've been running these through a longer set of load tests because my
  commits change the free space cache writeout.  It fixes commit stalls
  on large filesystems (~20T space used and up) that we have been
  triggering here.  We were seeing new writers blocked for 10 seconds or
  more during commits, which is far from good.

  Josef and I fixed up ENOSPC aborts when deleting huge files (3T or
  more), that are triggered because our metadata reservations were not
  properly accounting for crcs and were not replenishing during the
  truncate.

  Also in this series, a number of qgroup fixes from Fujitsu and Dave
  Sterba collected most of the pending cleanups from the list"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (93 commits)
  btrfs: quota: Update quota tree after qgroup relationship change.
  btrfs: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.
  btrfs: qgroup: clear STATUS_FLAG_ON in disabling quota.
  btrfs: Update btrfs qgroup status item when rescan is done.
  btrfs: qgroup: Fix dead judgement on qgroup_rescan_leaf() return value.
  btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created
  btrfs: Check qgroup level in kernel qgroup assign.
  btrfs: qgroup: allow to remove qgroup which has parent but no child.
  btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
  btrfs: qgroup: do a reservation in a higher level.
  Btrfs: qgroup, Account data space in more proper timings.
  Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
  Btrfs: qgroup: free reserved in exceeding quota.
  Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().
  btrfs: qgroup: fix limit args override whole limit struct
  btrfs: qgroup: update limit info in function btrfs_run_qgroups().
  btrfs: qgroup: consolidate the parameter of fucntion update_qgroup_limit_item().
  btrfs: qgroup: update qgroup in memory at the same time when we update it in btree.
  btrfs: qgroup: inherit limit info from srcgroup in creating snapshot.
  btrfs: Support busy loop of write and delete
  ...
2015-04-24 07:40:02 -07:00
Chris Mason 85db36cfb3 Btrfs: fix inode cache writeout
The code to fix stalls during free spache cache IO wasn't using
the correct root when waiting on the IO for inode caches.  This
is only a problem when the inode cache is enabled with

mount -o inode_cache

This fixes the inode cache writeout to preserve any error values and
makes sure not to override the root when inode cache writeout is done.

Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-23 17:47:34 -07:00
David Howells 2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Qu Wenruo e082f56313 btrfs: quota: Update quota tree after qgroup relationship change.
Previous patch modified the in memory struct but it's not written in
quota tree until next commit.
So user will still get old data using "btrfs qgroup show" after
assign/remove.

This patch will call btrfs_run_qgroups in assign ioctl so it will be
updated to in memory quota trees and user will get up-to-date results.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:53:00 -07:00
Qu Wenruo 9c8b35b1ba btrfs: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.
Operation like qgroups assigning/deleting qgroup relations will mostly
cause qgroup data inconsistent, since it needs to do the full rescan to
determine whether shared extents are exclusive or still shared in
parent qgroups.

But there are some exceptions, like qgroup with only exclusive extents
(qgroup->excl == qgroup->rfer), in that case, we only needs to
modify all its parents' excl and rfer.

So this patch adds a quick path for such qgroup in qgroup
assign/remove routine, and if quick path failed, the qgroup status will
be marked INCONSISTENT, and return 1 to info user-land.

BTW since the quick path is much the same of qgroup_excl_accounting(),
so move the core of it to __qgroup_excl_accounting() and reuse it.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:59 -07:00
Dongsheng Yang 8ea0ec9e01 btrfs: qgroup: clear STATUS_FLAG_ON in disabling quota.
we forgot to clear STATUS_FLAG_ON in quota_disable(), it
will cause a problem shown as below:

	# mount /dev/sdc /mnt
	# btrfs quota enable /mnt
	# btrfs quota disable /mnt
	# btrfs quota rescan /mnt
	quota rescan started <--- expecting it fail here.
	# echo $?
	0

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:58 -07:00
Qu Wenruo 53b7cde9d5 btrfs: Update btrfs qgroup status item when rescan is done.
Update qgroup status when rescan is done.

Before this patch, status item is not updated on rescan finish, which
causing the RESCAN and INCONSISTENT flags never cleared.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:57 -07:00
Qu Wenruo 3393168d22 btrfs: qgroup: Fix dead judgement on qgroup_rescan_leaf() return value.
Old qgroup_rescan_leaf() comment indicates ret == 2 as complete and
cleared INCONSISTENT flag.

This is not true since it will never return 2, and inside it no codes
will clear INCONSISTENT flag.
The flag clearance is done in btrfs_qgroup_rescan_work().
This caused the bug that INCONSISTENT flag is never cleared.

So change the comment and fix the dead judgment.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:55 -07:00
Qu Wenruo e09fe2d211 btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created
Btrfs will create qgroup on subvolume creation if quota is enabled, but
qgroup uses the high bits(currently 16 bits) as level, to build the
inheritance.

However it is fully possible a subvolume can be created with a
subvolumeid larger than 1 << BTRFS_QGROUP_LEVEL_SHIFT, so it will be
considered as level 1 and can't be assigned to other qgroup in level 1.

This patch will prevent such things so qgroup inheritance will not be
screwed up.
The downside is very clear, btrfs subvolume number limit will decrease
from (u64 max - 256(fisrt free objectid) - 256(last free objectid)) to
(u48 max -256(first free objectid)).
But we still have near u48(that's 15 digits in dec), so that should not
be a huge problem.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:54 -07:00
Qu Wenruo 8465ecec96 btrfs: Check qgroup level in kernel qgroup assign.
Although we have qgroup level check in btrfs-progs, it's not enough
since other programe may still call ioctl directly not using
btrfs-progs. For example, systemd.

But it's btrfs-progs to be blame since we don't provide a
full-function(like subvolume create things) btrfs library with enough
check, and only rely on kernel ioctl.

So Add level checks in kernel too.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:53 -07:00
Dongsheng Yang f5a6b1c53b btrfs: qgroup: allow to remove qgroup which has parent but no child.
When a qgroup has parents but no child, it should be removable in
Theory I think. But currently, we can not remove it when it has
either parent or child.

Example:
	# btrfs quota enable /mnt
	# btrfs qgroup create 1/0 /mnt
	# btrfs qgroup create 2/0 /mnt
	# btrfs qgroup assign 1/0 2/0 /mnt
	# btrfs qgroup show -pcre /mnt
qgroupid rfer  excl  max_rfer max_excl parent  child
-------- ----  ----  -------- -------- ------  -----
0/5      16384 16384 0        0        ---     ---
1/0      0     0     0        0        2/0     ---
2/0      0     0     0        0        ---     1/0

At this time, there is no subvol or qgroup depending on it.
Just a qgroup 2/0 is its parent, but 2/0 can work well without
1/0. So I think 1/0 should be removalbe. But:
	# btrfs qgroup destroy 1/0 /mnt
ERROR: unable to destroy quota group: Device or resource busy

This patch remove the check of qgroup->parent in removing it,
then we can remove a qgroup when it has a parent.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:52 -07:00
Dongsheng Yang 09870d2772 btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
When we create a subvol inheriting a qgroup, we need to check the level
of them. Otherwise, there is a chance a qgroup can inherit another qgroup
at the same level.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:51 -07:00
Dongsheng Yang e2d1f92399 btrfs: qgroup: do a reservation in a higher level.
There are two problems in qgroup:

a). The PAGE_CACHE is 4K, even when we are writing a data of 1K,
qgroup will reserve a 4K size. It will cause the last 3K in a qgroup
is not available to user.

b). When user is writing a inline data, qgroup will not reserve it,
it means this is a window we can exceed the limit of a qgroup.

The main idea of this patch is reserving the data size of write_bytes
rather than the reserve_bytes. It means qgroup will not care about
the data size btrfs will reserve for user, but only care about the
data size user is going to write. Then reserve it when user want to
write and release it in transaction committed.

In this way, qgroup can be released from the complex procedure in
btrfs and only do the reserve when user want to write and account
when the data is written in commit_transaction().

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:50 -07:00
Dongsheng Yang 237c0e9f1f Btrfs: qgroup, Account data space in more proper timings.
Currenly, in data writing, ->reserved is accounted in
fill_delalloc(), but ->may_use is released in clear_bit_hook()
which is called by btrfs_finish_ordered_io(). That's too late,
that said, between fill_delalloc() and btrfs_finish_ordered_io(),
the data is doublely accounted by qgroup. It will cause some
unexpected -EDQUOT.

Example:
	# btrfs quota enable /root/btrfs-auto-test/
	# btrfs subvolume create /root/btrfs-auto-test//sub
	Create subvolume '/root/btrfs-auto-test/sub'
	# btrfs qgroup limit 1G /root/btrfs-auto-test//sub
	dd if=/dev/zero of=/root/btrfs-auto-test//sub/file bs=1024 count=1500000
	dd: error writing '/root/btrfs-auto-test//sub/file': Disk quota exceeded
	681353+0 records in
	681352+0 records out
	697704448 bytes (698 MB) copied, 8.15563 s, 85.5 MB/s
It's (698 MB) when we got an -EDQUOT, but we limit it by 1G.

This patch move the btrfs_qgroup_reserve/free() for data from
btrfs_delalloc_reserve/release_metadata() to btrfs_check_data_free_space()
and btrfs_free_reserved_data_space(). Then the accounter in qgroup
will be updated at the same time with the accounter in space_info updated.
In this way, the unexpected -EDQUOT will be killed.

Reported-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:48 -07:00
Dongsheng Yang 31193213f1 Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
Currently, for pre_alloc or delay_alloc, the bytes will be accounted
in space_info by the three guys.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
But on the other hand, in qgroup, there are only two counters to account the
bytes, qgroup->reserved and qgroup->excl. And qg->reserved accounts
bytes in space_info->bytes_may_use and qg->excl accounts bytes in
space_info->used. So the bytes in space_info->reserved is not accounted
in qgroup. If so, there is a window we can exceed the quota limit when
bytes is in space_info->reserved.

Example:
	# btrfs quota enable /mnt
	# btrfs qgroup limit -e 10M /mnt
	# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
	# sync
	# btrfs qgroup show -pcre /mnt
qgroupid rfer     excl     max_rfer max_excl parent  child
-------- ----     ----     -------- -------- ------  -----
0/5      20987904 20987904 0        10485760 ---     ---

qg->excl is 20987904 larger than max_excl 10485760.

This patch introduce a new counter named may_use to qgroup, then
there are three counters in qgroup to account bytes in space_info
as below.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
qgroup->may_use           --- qgroup->reserved     --- qgroup->excl

With this patch applied:
	# btrfs quota enable /mnt
	# btrfs qgroup limit -e 10M /mnt
	# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
fallocate: /mnt/data9: fallocate failed: Disk quota exceeded
fallocate: /mnt/data10: fallocate failed: Disk quota exceeded
fallocate: /mnt/data11: fallocate failed: Disk quota exceeded
fallocate: /mnt/data12: fallocate failed: Disk quota exceeded
fallocate: /mnt/data13: fallocate failed: Disk quota exceeded
fallocate: /mnt/data14: fallocate failed: Disk quota exceeded
fallocate: /mnt/data15: fallocate failed: Disk quota exceeded
fallocate: /mnt/data16: fallocate failed: Disk quota exceeded
fallocate: /mnt/data17: fallocate failed: Disk quota exceeded
fallocate: /mnt/data18: fallocate failed: Disk quota exceeded
fallocate: /mnt/data19: fallocate failed: Disk quota exceeded
	# sync
	# btrfs qgroup show -pcre /mnt
qgroupid rfer    excl    max_rfer max_excl parent  child
-------- ----    ----    -------- -------- ------  -----
0/5      9453568 9453568 0        10485760 ---     ---

Reported-by: Cyril SCETBON <cyril.scetbon@free.fr>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:47 -07:00
Dongsheng Yang 804ca127fb Btrfs: qgroup: free reserved in exceeding quota.
When we exceed quota limit in writing, we will free
some reserved extent when we need to drop but not free
account in qgroup. It means, each time we exceed quota
in writing, there will be some remain space in qg->reserved
we can not use any more. If things go on like this, the
all space will be ate up.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:46 -07:00
Dongsheng Yang 4087cf24ae Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:44 -07:00
Dongsheng Yang 03477d945f btrfs: qgroup: fix limit args override whole limit struct
btrfs_limit_group use arg limit to override the old qgroup_limit of
corresponding qgroup. However, we should override part of old qgroup_limit
according to the bit which has been set in arg limit.

Signed-off-by: Fan Chengniang <fancn.fnst@cn.fujitsu.com>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:43 -07:00
Dongsheng Yang d3001ed3a8 btrfs: qgroup: update limit info in function btrfs_run_qgroups().
When we commit_transaction(), qgroups in btree should be updated.
But, limit info is not considered currently. It will cause a problem
when a qgroup of a snapshot inherit the limit info from srcqgroup,
then there is an inconsistency.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:42 -07:00
Dongsheng Yang 1510e71c62 btrfs: qgroup: consolidate the parameter of fucntion update_qgroup_limit_item().
Cleanup: Change the parameter of update_qgroup_limit_item() to the family of
update_qgroup_xxx_item().

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:41 -07:00
Dongsheng Yang e8c8541ac3 btrfs: qgroup: update qgroup in memory at the same time when we update it in btree.
When we call btrfs_qgroup_inherit() with BTRFS_QGROUP_INHERIT_SET_LIMITS,
btrfs will update the limit info of qgroup in btree but forget to update
the qgroup in rbtree at the same time. It obviousely will cause an inconsistency.

This patch fix it by updating the rbtree at the same time.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:40 -07:00
Dongsheng Yang 3eeb4d597e btrfs: qgroup: inherit limit info from srcgroup in creating snapshot.
Currently, when we snapshot a subvol, snapshot will not copy the limits
from srcqgroup.

This patch make the qgroup in snapshot inherit the limit info when create
a snapshot.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:52:38 -07:00
Zhao Lei c99f1b0c6c btrfs: Support busy loop of write and delete
Reproduce:
 while true; do
   dd if=/dev/zero of=/mnt/btrfs/file count=[75% fs_size]
   rm /mnt/btrfs/file
 done
 Then we can see above loop failed on NO_SPACE.

It it long-term problem since very beginning, because delayed-iput
after rm are not run.

We already have commit_transaction() in alloc_space code, but it is
not triggered in above case.
This patch trigger commit_transaction() to run delayed-iput and
reflash pinned-space to to make write success.

It is based on previous fix of delayed-iput in commit_transaction(),
need to be applied on top of:
btrfs: Fix NO_SPACE bug caused by delayed-iput

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:31:10 -07:00
Zhao Lei d7c151717a btrfs: Fix NO_SPACE bug caused by delayed-iput
Steps to reproduce:
  while true; do
    dd if=/dev/zero of=/btrfs_dir/file count=[fs_size * 75%]
    rm /btrfs_dir/file
    sync
  done

  And we'll see dd failed because btrfs return NO_SPACE.

Reason:
  Normally, btrfs_commit_transaction() call btrfs_run_delayed_iputs()
  in end to free fs space for next write, but sometimes it hadn't
  done work on time, because btrfs-cleaner thread get delayed-iputs
  from list before, but do iput() after next write.

  This is log:
  [ 2569.050776] comm=btrfs-cleaner func=btrfs_evict_inode() begin

  [ 2569.084280] comm=sync func=btrfs_commit_transaction() call btrfs_run_delayed_iputs()
  [ 2569.085418] comm=sync func=btrfs_commit_transaction() done btrfs_run_delayed_iputs()
  [ 2569.087554] comm=sync func=btrfs_commit_transaction() end

  [ 2569.191081] comm=dd begin
  [ 2569.790112] comm=dd func=__btrfs_buffered_write() ret=-28

  [ 2569.847479] comm=btrfs-cleaner func=add_pinned_bytes() 0 + 32677888 = 32677888
  [ 2569.849530] comm=btrfs-cleaner func=add_pinned_bytes() 32677888 + 23834624 = 56512512
  ...
  [ 2569.903893] comm=btrfs-cleaner func=add_pinned_bytes() 943976448 + 21762048 = 965738496
  [ 2569.908270] comm=btrfs-cleaner func=btrfs_evict_inode() end

Fix:
  Make btrfs_commit_transaction() wait current running btrfs-cleaner's
  delayed-iputs() done in end.

Test:
  Use script similar to above(more complex),
  before patch:
    7 failed in 100 * 20 loop.
  after patch:
    0 failed in 100 * 20 loop.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:41 -07:00
Zhao Lei 18d018ad2c btrfs: add WARN_ON() to check is space_info op current
space_info's value calculation is some complex and easy to cause
bug, add WARN_ON() to help debug.

Changelog v1->v2:
 Put WARN_ON()s under the ENOSPC_DEBUG mount option.
 Suggested by: David Sterba <dsterba@suse.cz>

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:35 -07:00
Zhao Lei c30666d466 btrfs: Set relative data on clear btrfs_block_group_cache->pinned
Bug1:
  space_info->bytes_readonly was set to very large(negative) value in
  btrfs_remove_block_group().

Reason:
  Current code set block_group_cache->pinned = 0 in btrfs_delete_unused_bgs(),
  but above space was not counted to space_info->bytes_readonly.

  Then in btrfs_remove_block_group():
    block_group->space_info->bytes_readonly -= block_group->key.offset;
  We can see following value in trace:
    btrfs_remove_block_group: pid=2677 comm=btrfs-cleaner WARNING: bytes_readonly=12582912, key.offset=134217728

Bug2:
  space_info->total_bytes_pinned grow to value larger than fs size.
  In a 1.2G fs, we can get following trace log:
  at first:
    ZL_DEBUG: add_pinned_bytes: pid=2710 comm=sync change total_bytes_pinned flags=1 869793792 + 95944704 = 965738496
  after some op:
    ZL_DEBUG: add_pinned_bytes: pid=2770 comm=sync change total_bytes_pinned flags=1 1780178944 + 95944704 = 1876123648
  after some op:
    ZL_DEBUG: add_pinned_bytes: pid=3193 comm=sync change total_bytes_pinned flags=1 2924568576 + 95551488 = 3020120064
  ...

Reason:
  Similar to bug1, we also need to adjust space_info->total_bytes_pinned
  in above code block.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:29 -07:00
Zhao Lei 264ca0f60b btrfs: Adjust commit-transaction condition to avoid NO_SPACE more
If we have any chance to make a successful write, we should not give up.

This patch adjust commit-transaction condition from:
  pinned >= wanted
to
  left + pinned >= wanted

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:24 -07:00
Zhao Lei f2ab76188e btrfs: Fix tail space processing in find_free_dev_extent()
It is another reason for NO_SPACE case.

When we found enough free space in loop and saved them to
max_hole_start/size before, and tail space contains pending extent,
origional innocent max_hole_start/size are reset in retry.

As a result, find_free_dev_extent() returns less space than it can,
and cause NO_SPACE in user program.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:18 -07:00
Zhao Lei 94b947b2f3 btrfs: fix condition of commit transaction
Old code bypass commit transaction when we don't have enough
pinned space, but another case is there exist freed bgs in current
transction, it have possibility to make alloc_chunk success.

This patch modify the condition to:
if (have_free_bg || have_pinned_space) commit_transaction()

Confirmed above action by printk before and after patch.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:26:40 -07:00
Chris Mason de249e66a7 Btrfs: fix uninit variable in clone ioctl
Commit 0d97a64e0 creates a new variable but doesn't always set it up.
This puts it back to the original method (key.offset + 1) for the cases
not covered by Filipe's new logic.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:03:58 -07:00
Filipe Manana ccccf3d672 Btrfs: fix inode eviction infinite loop after cloning into it
If we attempt to clone a 0 length region into a file we can end up
inserting a range in the inode's extent_io tree with a start offset
that is greater then the end offset, which triggers immediately the
following warning:

[ 3914.619057] WARNING: CPU: 17 PID: 4199 at fs/btrfs/extent_io.c:435 insert_state+0x4b/0x10b [btrfs]()
[ 3914.620886] BTRFS: end < start 4095 4096
(...)
[ 3914.638093] Call Trace:
[ 3914.638636]  [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[ 3914.639620]  [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[ 3914.640789]  [<ffffffffa03ca44f>] ? insert_state+0x4b/0x10b [btrfs]
[ 3914.642041]  [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[ 3914.643236]  [<ffffffffa03ca44f>] insert_state+0x4b/0x10b [btrfs]
[ 3914.644441]  [<ffffffffa03ca729>] __set_extent_bit+0x107/0x3f4 [btrfs]
[ 3914.645711]  [<ffffffffa03cb256>] lock_extent_bits+0x65/0x1bf [btrfs]
[ 3914.646914]  [<ffffffff8142b2fb>] ? _raw_spin_unlock+0x28/0x33
[ 3914.648058]  [<ffffffffa03cbac4>] ? test_range_bit+0xcc/0xde [btrfs]
[ 3914.650105]  [<ffffffffa03cb3c3>] lock_extent+0x13/0x15 [btrfs]
[ 3914.651361]  [<ffffffffa03db39e>] lock_extent_range+0x3d/0xcd [btrfs]
[ 3914.652761]  [<ffffffffa03de1fe>] btrfs_ioctl_clone+0x278/0x388 [btrfs]
[ 3914.654128]  [<ffffffff811226dd>] ? might_fault+0x58/0xb5
[ 3914.655320]  [<ffffffffa03e0909>] btrfs_ioctl+0xb51/0x2195 [btrfs]
(...)
[ 3914.669271] ---[ end trace 14843d3e2e622fc1 ]---

This later makes the inode eviction handler enter an infinite loop that
keeps dumping the following warning over and over:

[ 3915.117629] WARNING: CPU: 22 PID: 4228 at fs/btrfs/extent_io.c:435 insert_state+0x4b/0x10b [btrfs]()
[ 3915.119913] BTRFS: end < start 4095 4096
(...)
[ 3915.137394] Call Trace:
[ 3915.137913]  [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[ 3915.139154]  [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[ 3915.140316]  [<ffffffffa03ca44f>] ? insert_state+0x4b/0x10b [btrfs]
[ 3915.141505]  [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[ 3915.142709]  [<ffffffffa03ca44f>] insert_state+0x4b/0x10b [btrfs]
[ 3915.143849]  [<ffffffffa03ca729>] __set_extent_bit+0x107/0x3f4 [btrfs]
[ 3915.145120]  [<ffffffffa038c1e3>] ? btrfs_kill_super+0x17/0x23 [btrfs]
[ 3915.146352]  [<ffffffff811548f6>] ? deactivate_locked_super+0x3b/0x50
[ 3915.147565]  [<ffffffffa03cb256>] lock_extent_bits+0x65/0x1bf [btrfs]
[ 3915.148785]  [<ffffffff8142b7e2>] ? _raw_write_unlock+0x28/0x33
[ 3915.149931]  [<ffffffffa03bc325>] btrfs_evict_inode+0x196/0x482 [btrfs]
[ 3915.151154]  [<ffffffff81168904>] evict+0xa0/0x148
[ 3915.152094]  [<ffffffff811689e5>] dispose_list+0x39/0x43
[ 3915.153081]  [<ffffffff81169564>] evict_inodes+0xdc/0xeb
[ 3915.154062]  [<ffffffff81154418>] generic_shutdown_super+0x49/0xef
[ 3915.155193]  [<ffffffff811546d1>] kill_anon_super+0x13/0x1e
[ 3915.156274]  [<ffffffffa038c1e3>] btrfs_kill_super+0x17/0x23 [btrfs]
(...)
[ 3915.167404] ---[ end trace 14843d3e2e622fc2 ]---

So just bail out of the clone ioctl if the length of the region to clone
is zero, without locking any extent range, in order to prevent this issue
(same behaviour as a pwrite with a 0 length for example).

This is trivial to reproduce. For example, the steps for the test I just
made for fstests:

  mkfs.btrfs -f SCRATCH_DEV
  mount SCRATCH_DEV $SCRATCH_MNT

  touch $SCRATCH_MNT/foo
  touch $SCRATCH_MNT/bar

  $CLONER_PROG -s 0 -d 4096 -l 0 $SCRATCH_MNT/foo $SCRATCH_MNT/bar
  umount $SCRATCH_MNT

A test case for fstests follows soon.

CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:03:28 -07:00
Filipe Manana 113e828386 Btrfs: fix inode eviction infinite loop after extent_same ioctl
If we pass a length of 0 to the extent_same ioctl, we end up locking an
extent range with a start offset greater then its end offset (if the
destination file's offset is greater than zero). This results in a warning
from extent_io.c:insert_state through the following call chain:

  btrfs_extent_same()
    btrfs_double_lock()
      lock_extent_range()
        lock_extent(inode->io_tree, offset, offset + len - 1)
          lock_extent_bits()
            __set_extent_bit()
              insert_state()
                --> WARN_ON(end < start)

This leads to an infinite loop when evicting the inode. This is the same
problem that my previous patch titled
"Btrfs: fix inode eviction infinite loop after cloning into it" addressed
but for the extent_same ioctl instead of the clone ioctl.

CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:03:27 -07:00
Filipe Manana df858e7672 Btrfs: fix range cloning when same inode used as source and destination
While searching for extents to clone we might find one where we only use
a part of it coming from its tail. If our destination inode is the same
the source inode, we end up removing the tail part of the extent item and
insert after a new one that point to the same extent with an adjusted
key file offset and data offset. After this we search for the next extent
item in the fs/subvol tree with a key that has an offset incremented by
one. But this second search leaves us at the new extent item we inserted
previously, and since that extent item has a non-zero data offset, it
it can make us call btrfs_drop_extents with an empty range (start == end)
which causes the following warning:

[23978.537119] WARNING: CPU: 6 PID: 16251 at fs/btrfs/file.c:550 btrfs_drop_extent_cache+0x43/0x385 [btrfs]()
(...)
[23978.557266] Call Trace:
[23978.557978]  [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[23978.559191]  [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[23978.560699]  [<ffffffffa047f0ea>] ? btrfs_drop_extent_cache+0x43/0x385 [btrfs]
[23978.562389]  [<ffffffff8104544d>] warn_slowpath_null+0x1a/0x1c
[23978.563613]  [<ffffffffa047f0ea>] btrfs_drop_extent_cache+0x43/0x385 [btrfs]
[23978.565103]  [<ffffffff810e3a18>] ? time_hardirqs_off+0x15/0x28
[23978.566294]  [<ffffffff81079ff8>] ? trace_hardirqs_off+0xd/0xf
[23978.567438]  [<ffffffffa047f73d>] __btrfs_drop_extents+0x6b/0x9e1 [btrfs]
[23978.568702]  [<ffffffff8107c03f>] ? trace_hardirqs_on+0xd/0xf
[23978.569763]  [<ffffffff811441c0>] ? ____cache_alloc+0x69/0x2eb
[23978.570817]  [<ffffffff81142269>] ? virt_to_head_page+0x9/0x36
[23978.571872]  [<ffffffff81143c15>] ? cache_alloc_debugcheck_after.isra.42+0x16c/0x1cb
[23978.573466]  [<ffffffff811420d5>] ? kmemleak_alloc_recursive.constprop.52+0x16/0x18
[23978.574962]  [<ffffffffa0480d07>] btrfs_drop_extents+0x66/0x7f [btrfs]
[23978.576179]  [<ffffffffa049aa35>] btrfs_clone+0x516/0xaf5 [btrfs]
[23978.577311]  [<ffffffffa04983dc>] ? lock_extent_range+0x7b/0xcd [btrfs]
[23978.578520]  [<ffffffffa049b2a2>] btrfs_ioctl_clone+0x28e/0x39f [btrfs]
[23978.580282]  [<ffffffffa049d9ae>] btrfs_ioctl+0xb51/0x219a [btrfs]
(...)
[23978.591887] ---[ end trace 988ec2a653d03ed3 ]---

Then we attempt to insert a new extent item with a key that already
exists, which makes btrfs_insert_empty_item return -EEXIST resulting in
abortion of the current transaction:

[23978.594355] WARNING: CPU: 6 PID: 16251 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]()
(...)
[23978.622589] Call Trace:
[23978.623181]  [<ffffffff81425fd9>] dump_stack+0x4c/0x65
[23978.624359]  [<ffffffff81045390>] warn_slowpath_common+0xa1/0xbb
[23978.625573]  [<ffffffffa044ab6c>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs]
[23978.626971]  [<ffffffff810453f0>] warn_slowpath_fmt+0x46/0x48
[23978.628003]  [<ffffffff8108a6c8>] ? vprintk_default+0x1d/0x1f
[23978.629138]  [<ffffffffa044ab6c>] __btrfs_abort_transaction+0x52/0x114 [btrfs]
[23978.630528]  [<ffffffffa049ad1b>] btrfs_clone+0x7fc/0xaf5 [btrfs]
[23978.631635]  [<ffffffffa04983dc>] ? lock_extent_range+0x7b/0xcd [btrfs]
[23978.632886]  [<ffffffffa049b2a2>] btrfs_ioctl_clone+0x28e/0x39f [btrfs]
[23978.634119]  [<ffffffffa049d9ae>] btrfs_ioctl+0xb51/0x219a [btrfs]
(...)
[23978.647714] ---[ end trace 988ec2a653d03ed4 ]---

This is wrong because we should not process the extent item that we just
inserted previously, and instead process the extent item that follows it
in the tree

For example for the test case I wrote for fstests:

   bs=$((64 * 1024))
   mkfs.btrfs -f -l $bs -O ^no-holes /dev/sdc
   mount /dev/sdc /mnt

   xfs_io -f -c "pwrite -S 0xaa $(($bs * 2)) $(($bs * 2))" /mnt/foo

   $CLONER_PROG -s $((3 * $bs)) -d $((267 * $bs)) -l 0 /mnt/foo /mnt/foo
   $CLONER_PROG -s $((217 * $bs)) -d $((95 * $bs)) -l 0 /mnt/foo /mnt/foo

The second clone call fails with -EEXIST, because when we process the
first extent item (offset 262144), we drop part of it (counting from the
end) and then insert a new extent item with a key greater then the key we
found. The next time we search the tree we search for a key with offset
262144 + 1, which leaves us at the new extent item we have just inserted
but we think it refers to an extent that we need to clone.

Fix this by ensuring the next search key uses an offset corresponding to
the offset of the key we found previously plus the data length of the
corresponding extent item. This ensures we skip new extent items that we
inserted and works for the case of implicit holes too (NO_HOLES feature).

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:03:26 -07:00
Al Viro 2ba48ce513 mirror O_APPEND and O_DIRECT into iocb->ki_flags
... avoiding write_iter/fcntl races.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:30:22 -04:00
Al Viro 3309dd04cb switch generic_write_checks() to iocb and iter
... returning -E... upon error and amount of data left in iter after
(possible) truncation upon success.  Note, that normal case gives
a non-zero (positive) return value, so any tests for != 0 _must_ be
updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/ext4/file.c
2015-04-11 22:30:21 -04:00
Al Viro 0fa6b005af generic_write_checks(): drop isblk argument
all remaining callers are passing 0; some just obscure that fact.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:48 -04:00
Omar Sandoval 22c6186ece direct_IO: remove rw from a_ops->direct_IO()
Now that no one is using rw, remove it completely.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:45 -04:00
Omar Sandoval 6f67376318 direct_IO: use iov_iter_rw() instead of rw everywhere
The rw parameter to direct_IO is redundant with iov_iter->type, and
treated slightly differently just about everywhere it's used: some users
do rw & WRITE, and others do rw == WRITE where they should be doing a
bitwise check. Simplify this with the new iov_iter_rw() helper, which
always returns either READ or WRITE.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:45 -04:00
Omar Sandoval 17f8c842d2 Remove rw from {,__,do_}blockdev_direct_IO()
Most filesystems call through to these at some point, so we'll start
here.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:44 -04:00
Al Viro 5d5d568975 make new_sync_{read,write}() static
All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:40 -04:00
Al Viro c0fec3a98b Merge branch 'iocb' into for-next 2015-04-11 22:24:41 -04:00
Chris Mason cdfb080e18 Btrfs: fix use after free when close_ctree frees the orphan_rsv
Near the end of close_ctree, we're calling btrfs_free_block_rsv
to free up the orphan rsv.  The problem is this call updates the
space_info, which has already been freed.

This adds a new __ function that directly calls kfree instead of trying
to update the space infos.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:07:29 -07:00
Chris Mason 1bbc621ef2 Btrfs: allow block group cache writeout outside critical section in commit
We loop through all of the dirty block groups during commit and write
the free space cache.  In order to make sure the cache is currect, we do
this while no other writers are allowed in the commit.

If a large number of block groups are dirty, this can introduce long
stalls during the final stages of the commit, which can block new procs
trying to change the filesystem.

This commit changes the block group cache writeout to take appropriate
locks and allow it to run earlier in the commit.  We'll still have to
redo some of the block groups, but it means we can get most of the work
out of the way without blocking the entire FS.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:07:22 -07:00
Chris Mason 2b10826800 Btrfs: don't use highmem for free space cache pages
In order to create the free space cache concurrently with FS modifications,
we need to take a few block group locks.

The cache code also does kmap, which would schedule with the locks held.
Instead of going through kmap_atomic, lets just use lowmem for the cache
pages.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:07:18 -07:00
Chris Mason c9dc4c6578 Btrfs: two stage dirty block group writeout
Block group cache writeout is currently waiting on the pages for each
block group cache before moving on to writing the next one.  This commit
switches things around to send down all the caches and then wait on them
in batches.

The end result is much faster, since we're keeping the disk pipeline
full.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:07:11 -07:00
Chris Mason 4c6d1d85ad btrfs: move struct io_ctl into ctree.h and rename it
We'll need to put the io_ctl into the block_group cache struct, so
name it struct btrfs_io_ctl and move it into ctree.h

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:07:04 -07:00
Josef Bacik 3bce876fd5 Btrfs: don't steal from the global reserve if we don't have the space
btrfs_evict_inode() needs to be more careful about stealing from the
global_rsv.  We dont' want to end up aborting commit with ENOSPC just
because the evict_inode code was too greedy.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:06:59 -07:00
Josef Bacik 365c531377 Btrfs: don't commit the transaction in the async space flushing
We're triggering a huge number of commits from
btrfs_async_reclaim_metadata_space.  These aren't really requried,
because everyone calling the async reclaim code is going to end up
triggering a commit on their own.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:06:54 -07:00
Josef Bacik cb723e4919 Btrfs: reserve space for block groups
This changes our delayed refs calculations to include the space needed
to write back dirty block groups.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:06:48 -07:00
Chris Mason 28f75a0e6c Btrfs: refill block reserves during truncate
When truncate starts, it allocates some space in the block reserves so
that we'll have enough to update metadata along the way.

For very large files, we can easily go through all of that space as we
loop through the extents.  This changes truncate to refill the space
reservation as it progresses through the file.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:06:34 -07:00
Josef Bacik 1262133b8d Btrfs: account for crcs in delayed ref processing
As we delete large extents, we end up doing huge amounts of COW in order
to delete the corresponding crcs.  This adds accounting so that we keep
track of that space and flushing of delayed refs so that we don't build
up too much delayed crc work.

This helps limit the delayed work that must be done at commit time and
tries to avoid ENOSPC aborts because the crcs eat all the global
reserves.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:04:47 -07:00
Chris Mason 28ed1345a5 btrfs: actively run the delayed refs while deleting large files
When we are deleting large files with large extents, we are building up
a huge set of delayed refs for processing.  Truncate isn't checking
often enough to see if we need to back off and process those, or let
a commit proceed.

The end result is long stalls after the rm, and very long commit times.
During the commits, other processes back up waiting to start new
transactions and we get into trouble.

Signed-off-by: Chris Mason <clm@fb.com>
2015-04-10 14:00:14 -07:00
Guenter Roeck 4a3d1caf8a fs: btrfs: Add missing include file
Building alpha:allmodconfig fails with

fs/btrfs/inode.c: In function 'check_direct_IO':
fs/btrfs/inode.c:8050:2: error: implicit declaration of function 'iov_iter_alignment'

due to a missing include file.

Fixes: 3737c63e1fb0 ("fs: move struct kiocb to fs.h")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-01 12:32:07 -07:00
Chris Mason dd82525956 Btrfs: free and unlock our path before btrfs_free_and_pin_reserved_extent()
The error handling path for alloc_reserved_tree_block is calling
btrfs_free_and_pin_reserved_extent with a spinning tree lock held.  This
might sleep as we allocate extent_state objects:

 BUG: sleeping function called from invalid context at mm/slub.c:1268
 in_atomic(): 1, irqs_disabled(): 0, pid: 11093, name: kworker/u4:7
 5 locks held by kworker/u4:7/11093:
  #0:  ("%s-%s""btrfs", name){++++.+}, at: [<ffffffff81091d51>] process_one_work+0x151/0x520
  #1:  ((&work->normal_work)){+.+.+.}, at: [<ffffffff81091d51>] process_one_work+0x151/0x520
  #2:  (sb_internal){++++.+}, at: [<ffffffffa003a70e>] start_transaction+0x43e/0x590 [btrfs]
  #3:  (&head_ref->mutex){+.+...}, at: [<ffffffffa0089f8c>] btrfs_delayed_ref_lock+0x4c/0x240 [btrfs]
  #4:  (btrfs-extent-00){++++..}, at: [<ffffffffa007697b>] btrfs_clear_lock_blocking_rw+0x9b/0x150 [btrfs]
 CPU: 0 PID: 11093 Comm: kworker/u4:7 Tainted: G        W 4.0.0-rc6-default+ #246
 Hardware name: Intel Corporation Santa Rosa platform/Matanzas, BIOS TSRSCRB1.86C.0047.B00.0610170821 10/17/06
 Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
  00000000000004f4 ffff88006dd17848 ffffffff81ab0e3b ffff88006dd17848
  ffff88007a944760 ffff88006dd17868 ffffffff8109d516 ffff88006dd17898
  0000000000000000 ffff88006dd17898 ffffffff8109d5b2 ffffffff81aba2bb
 Call Trace:
  [<ffffffff81ab0e3b>] dump_stack+0x4f/0x6c
  [<ffffffff8109d516>] ___might_sleep+0xf6/0x140
  [<ffffffff8109d5b2>] __might_sleep+0x52/0x90
  [<ffffffff81aba2bb>] ? ftrace_call+0x5/0x34
  [<ffffffff81196363>] kmem_cache_alloc+0x163/0x1b0
  [<ffffffffa0056f31>] ? alloc_extent_state+0x31/0x150 [btrfs]
  [<ffffffffa0056f20>] ? alloc_extent_state+0x20/0x150 [btrfs]
  [<ffffffffa0056f31>] alloc_extent_state+0x31/0x150 [btrfs]
  [<ffffffffa005805b>] __set_extent_bit+0x37b/0x5d0 [btrfs]
  [<ffffffff81aba2bb>] ? ftrace_call+0x5/0x34
  [<ffffffffa005888d>] ? set_extent_bit+0xd/0x30 [btrfs]
  [<ffffffffa00588a3>] set_extent_bit+0x23/0x30 [btrfs]
  [<ffffffffa0058e80>] set_extent_dirty+0x20/0x30 [btrfs]
  [<ffffffffa00195ba>] pin_down_extent+0xaa/0x170 [btrfs]
  [<ffffffffa001d8ef>] __btrfs_free_reserved_extent+0xcf/0x160 [btrfs]
  [<ffffffffa0023856>] btrfs_free_and_pin_reserved_extent+0x16/0x20 [btrfs]
  [<ffffffffa002482a>] __btrfs_run_delayed_refs+0xfca/0x1290 [btrfs]
  [<ffffffffa0026eae>] btrfs_run_delayed_refs+0x6e/0x2e0 [btrfs]
  [<ffffffffa0027378>] delayed_ref_async_start+0x48/0xb0 [btrfs]
  [<ffffffffa006c883>] normal_work_helper+0x83/0x350 [btrfs]
  [<ffffffffa006cd79>] ? btrfs_extent_refs_helper+0x9/0x20 [btrfs]
  [<ffffffffa006cd82>] btrfs_extent_refs_helper+0x12/0x20 [btrfs]
  [<ffffffff81091dcb>] process_one_work+0x1cb/0x520
  [<ffffffff81091d51>] ? process_one_work+0x151/0x520
  [<ffffffff811c7abf>] ? seq_read+0x3f/0x400
  [<ffffffff8109260b>] worker_thread+0x5b/0x4e0
  [<ffffffff81097be2>] ? __kthread_parkme+0x12/0xa0
  [<ffffffff810925b0>] ? rescuer_thread+0x450/0x450
  [<ffffffff81098686>] kthread+0xf6/0x120
  [<ffffffff81098590>] ? flush_kthread_worker+0x1b0/0x1b0
  [<ffffffff81ab8088>] ret_from_fork+0x58/0x90
  [<ffffffff81098590>] ? flush_kthread_worker+0x1b0/0x1b0
 ------------[ cut here ]------------

This changes things to free the path first, which will also unlock the
extent buffer.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: Dave Sterba <dsterba@suse.cz>
Tested-by: Dave Sterba <dsterba@suse.cz>
2015-04-01 08:36:05 -07:00
Liu Bo e56a951e01 Btrfs: Remove the check for old-style mkfs
This was used to make sure that a fresh btrfs from an older mkfs.btrfs,
but it also allows us to mount a buggy btrfs if this btrfs has the right
superblock head part but has something wrong with chunk tree part[1], and
after that we can hit BUG_ON()s set in the code to prevent something
impossible.

Since David has released "Btrfs progs v3.19-rc2", just remove the check,
if anyone who wants to make a fresh btrfs, please use the latest one.

[1]: http://www.spinics.net/lists/linux-btrfs/msg42358.html

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 18:10:25 -07:00
Jeff Mahoney 727b9784b6 btrfs: cleanup orphans while looking up default subvolume
Orphans in the fs tree are cleaned up via open_ctree and subvolume
orphans are cleaned via btrfs_lookup_dentry -- except when a default
subvolume is in use.  The name for the default subvolume uses a manual
lookup that doesn't trigger orphan cleanup and needs to trigger it
manually as well. This doesn't apply to the remount case since the
subvolumes are cleaned up by walking the root radix tree.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 18:10:25 -07:00
Tom Van Braeckel d862095829 btrfs: explicitly set control file's private_data
The private_data member of the Btrfs control device file
(/dev/btrfs-control) is used to hold the current transaction and needs
to be initialized to NULL to signify that no transaction is in progress.

We explicitly set the control file's private_data to NULL to be
independent of whatever value the misc subsystem initializes it to.

Backstory:
----------

The misc subsystem (which is used by /dev/btrfs-control) initializes
a file's private_data to point to the misc device when a driver has
registered a custom open file operation and initializes it to NULL
when a custom open file operation has *not* been provided.

This subtle quirk is confusing, to the point where kernel code registers
*empty* file open operations to have private_data point to the misc
device structure.

And it leads to bugs, where the addition or removal of a custom open
file operation surprisingly changes the initial contents of a file's
private_data structure.

To simplify things in the misc subsystem, a patch [1] has been proposed
to *always* set private_data to point to the misc device instead of
only doing this when a custom open file operation has been registered.

But before we can fix this in the misc subsystem itself, we need to
modify the (few) drivers that rely on this very subtle behavior.

[1] https://lkml.org/lkml/2014/12/4/939

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Tom Van Braeckel <tomvanbraeckel@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 18:10:24 -07:00
Chengyu Song 26e726afe0 btrfs: incorrect handling for fiemap_fill_next_extent return
fiemap_fill_next_extent returns 0 on success, -errno on error, 1 if this was
the last extent that will fit in user array. If 1 is returned, the return
value may eventually returned to user space, which should not happen, according
to manpage of ioctl.

Signed-off-by: Chengyu Song <csong84@gatech.edu>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 18:10:24 -07:00
David Sterba 3c3b04d10f btrfs: don't accept bare namespace as a valid xattr
Due to insufficient check in btrfs_is_valid_xattr, this unexpectedly
works:

 $ touch file
 $ setfattr -n user. -v 1 file
 $ getfattr -d file
user.="1"

ie. the missing attribute name after the namespace.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94291
Reported-by: William Douglas <william.douglas@intel.com>
CC: <stable@vger.kernel.org> # 2.6.29+
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 18:10:24 -07:00
Filipe Manana dcc82f4783 Btrfs: fix log tree corruption when fs mounted with -o discard
While committing a transaction we free the log roots before we write the
new super block. Freeing the log roots implies marking the disk location
of every node/leaf (metadata extent) as pinned before the new super block
is written. This is to prevent the disk location of log metadata extents
from being reused before the new super block is written, otherwise we
would have a corrupted log tree if before the new super block is written
a crash/reboot happens and the location of any log tree metadata extent
ended up being reused and rewritten.

Even though we pinned the log tree's metadata extents, we were issuing a
discard against them if the fs was mounted with the -o discard option,
resulting in corruption of the log tree if a crash/reboot happened before
writing the new super block - the next time the fs was mounted, during
the log replay process we would find nodes/leafs of the log btree with
a content full of zeroes, causing the process to fail and require the
use of the tool btrfs-zero-log to wipeout the log tree (and all data
previously fsynced becoming lost forever).

Fix this by not doing a discard when pinning an extent. The discard will
be done later when it's safe (after the new super block is committed) at
extent-tree.c:btrfs_finish_extent_commit().

Fixes: e688b7252f (Btrfs: fix extent pinning bugs in the tree log)
CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:56:24 -07:00
Filipe Manana 2f2ff0ee5e Btrfs: fix metadata inconsistencies after directory fsync
We can get into inconsistency between inodes and directory entries
after fsyncing a directory. The issue is that while a directory gets
the new dentries persisted in the fsync log and replayed at mount time,
the link count of the inode that directory entries point to doesn't
get updated, staying with an incorrect link count (smaller then the
correct value). This later leads to stale file handle errors when
accessing (including attempt to delete) some of the links if all the
other ones are removed, which also implies impossibility to delete the
parent directories, since the dentries can not be removed.

Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2),
when fsyncing a directory, new files aren't logged (their metadata and
dentries) nor any child directories. So this patch fixes this issue too,
since it has the same resolution as the incorrect inode link count issue
mentioned before.

This is very easy to reproduce, and the following excerpt from my test
case for xfstests shows how:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create our main test file and directory.
  $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io
  mkdir $SCRATCH_MNT/mydir

  # Make sure all metadata and data are durably persisted.
  sync

  # Add a hard link to 'foo' inside our test directory and fsync only the
  # directory. The btrfs fsync implementation had a bug that caused the new
  # directory entry to be visible after the fsync log replay but, the inode
  # of our file remained with a link count of 1.
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2

  # Add a few more links and new files.
  # This is just to verify nothing breaks or gives incorrect results after the
  # fsync log is replayed.
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3
  $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io
  ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2

  # Add some subdirectories and new files and links to them. This is to verify
  # that after fsyncing our top level directory 'mydir', all the subdirectories
  # and their files/links are registered in the fsync log and exist after the
  # fsync log is replayed.
  mkdir -p $SCRATCH_MNT/mydir/x/y/z
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link
  touch $SCRATCH_MNT/mydir/x/y/z/qwerty

  # Now fsync only our top directory.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir

  # And fsync now our new file named 'hello', just to verify later that it has
  # the expected content and that the previous fsync on the directory 'mydir' had
  # no bad influence on this fsync.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # Verify the content of our file 'foo' remains the same as before, 8192 bytes,
  # all with the value 0xaa.
  echo "File 'foo' content after log replay:"
  od -t x1 $SCRATCH_MNT/foo

  # Remove the first name of our inode. Because of the directory fsync bug, the
  # inode's link count was 1 instead of 5, so removing the 'foo' name ended up
  # deleting the inode and the other names became stale directory entries (still
  # visible to applications). Attempting to remove or access the remaining
  # dentries pointing to that inode resulted in stale file handle errors and
  # made it impossible to remove the parent directories since it was impossible
  # for them to become empty.
  echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)"
  rm -f $SCRATCH_MNT/foo

  # Now verify that all files, links and directories created before fsyncing our
  # directory exist after the fsync log was replayed.
  [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing"
  [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing"
  [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing"
  [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing"
  [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \
      echo "Link mydir/x/y/foo_y_link is missing"
  [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \
      echo "Link mydir/x/y/z/foo_z_link is missing"
  [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \
      echo "File mydir/x/y/z/qwerty is missing"

  # We expect our file here to have a size of 64Kb and all the bytes having the
  # value 0xff.
  echo "file 'hello' content after log replay:"
  od -t x1 $SCRATCH_MNT/hello

  # Now remove all files/links, under our test directory 'mydir', and verify we
  # can remove all the directories.
  rm -f $SCRATCH_MNT/mydir/x/y/z/*
  rmdir $SCRATCH_MNT/mydir/x/y/z
  rm -f $SCRATCH_MNT/mydir/x/y/*
  rmdir $SCRATCH_MNT/mydir/x/y
  rmdir $SCRATCH_MNT/mydir/x
  rm -f $SCRATCH_MNT/mydir/*
  rmdir $SCRATCH_MNT/mydir

  # An fsck, run by the fstests framework everytime a test finishes, also detected
  # the inconsistency and printed the following error message:
  #
  # root 5 inode 257 errors 2001, no inode item, link count wrong
  #    unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref
  #    unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref

  status=0
  exit

The expected golden output for the test is:

  wrote 8192/8192 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  wrote 65536/65536 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  File 'foo' content after log replay:
  0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
  *
  0020000
  file 'foo' link count after log replay: 5
  file 'hello' content after log replay:
  0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  *
  0200000

Which is the output after this patch and when running the test against
ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's
output is:

  wrote 8192/8192 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  wrote 65536/65536 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  File 'foo' content after log replay:
  0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
  *
  0020000
  file 'foo' link count after log replay: 1
  Link mydir/foo_2 is missing
  Link mydir/foo_3 is missing
  Link mydir/x/y/foo_y_link is missing
  Link mydir/x/y/z/foo_z_link is missing
  File mydir/x/y/z/qwerty is missing
  file 'hello' content after log replay:
  0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  *
  0200000
  rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory
  rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory
  rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory
  rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle
  rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle
  rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty

Fsck, without this fix, also complains about the wrong link count:

  root 5 inode 257 errors 2001, no inode item, link count wrong
      unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref
      unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref

So fix this by logging the inodes that the dentries point to when
fsyncing a directory.

A test case for xfstests follows.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:56:23 -07:00
Filipe Manana bf69196045 Btrfs: change the insertion criteria for the qgroup operations rbtree
After looking at Liu Bo's recent patch (titled
"Btrfs: fix comp_oper to get right order") I realized the search made by
qgroup_oper_exists() was buggy because its rbtree navigation comparison
function, comp_oper_exist(), only looks at the fields bytenr and ref_root
of a tree node, ignoring the seq field completely. This was wrong because
when we insert a node into the rbtree we use comp_oper(), which takes a
decision based first on bytenr, then on seq and then on the ref_root field.
That means qgroup_oper_exists() could miss the fact that at least one
operation with given bytenr and ref_root exists.

Consider the following simple example of a 3 nodes qgroup operations
rbtree (created using comp_oper before this patch), where each node's key
is a tuple with the shape (bytenr, seq, ref_root, op):

                          [ (4096, 2, 20, op X) ]
                         /                       \
                        /                         \
   [ (4096, 1, 5, op Y) ]                         [ (4096, 3, 10, op Z) ]

qgroup_oper_exists() when called to search for an existing operation for
bytenr 4096 and ref root 10 wouldn't find anything because it would go to
the left subtree instead of the right subtree, since comp_oper_exits()
ignores the seq field completely.

Fix this by changing the insertion navigation function to use the ref_root
field right after using the bytenr field and before using the seq field,
so that qgroup_oper_exists() / comp_oper_exist() work as expected.

This patch applies on top of the patch mentioned above from Liu.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:52 -07:00
Filipe Manana 3d850dd448 Btrfs: add missing inode item update in fallocate()
If we fallocate(), without the keep size flag, into an area already covered
by an extent previously fallocated, we were updating the inode's i_size but
we weren't updating the inode item in the fs/subvol tree. A following umount
+ mount would result in a loss of the inode's size (and an fsync would miss
too the fact that the inode changed).

Reproducer:

  $ mkfs.btrfs -f /dev/sdd
  $ mount /dev/sdd /mnt
  $ fallocate -n -l 1M /mnt/foobar
  $ fallocate -l 512K /mnt/foobar
  $ umount /mnt
  $ mount /dev/sdd /mnt
  $ od -t x1 /mnt/foobar
  0000000

The expected result is:

  $ od -t x1 /mnt/foobar
  0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  *
  2000000

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:52 -07:00
Filipe Manana 5f806c3ae2 Btrfs: incremental send, remove dead code
The logic to detect path loops when attempting to apply a pending
directory rename, introduced in commit
f959492fc1 (Btrfs: send, fix more issues related to directory renames)
is no longer needed, and the respective fstests test case for that commit,
btrfs/045, now passes without this code (as well as all the other test
cases for send/receive).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:52 -07:00
Filipe Manana 8996a48c0a Btrfs: incremental send, clear name from cache after orphanization
If a directory's reference ends up being orphanized, because the inode
currently being processed has a new path that matches that directory's
path, make sure we evict the name of the directory from the name cache.
This is because there might be descendent inodes (either directories or
regular files) that will be orphanized later too, and therefore the
orphan name of the ancestor must be used, otherwise we send issue rename
operations with a wrong path in the send stream.

Reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir -p /mnt/data/n1/n2/p1/p2
  $ mkdir /mnt/data/n4
  $ mkdir -p /mnt/data/p1/p2

  $ btrfs subvolume snapshot -r /mnt /mnt/snap1

  $ mv /mnt/data/p1/p2 /mnt/data
  $ mv /mnt/data/n1/n2/p1/p2 /mnt/data/p1
  $ mv /mnt/data/p2 /mnt/data/n1/n2/p1
  $ mv /mnt/data/n1/n2 /mnt/data/p1
  $ mv /mnt/data/p1 /mnt/data/n4
  $ mv /mnt/data/n4/p1/n2/p1 /mnt/data

  $ btrfs subvolume snapshot -r /mnt /mnt/snap2

  $ btrfs send /mnt/snap1 -f /tmp/1.send
  $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.send

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt2
  $ btrfs receive /mnt2 -f /tmp/1.send
  $ btrfs receive /mnt2 -f /tmp/2.send
  ERROR: rename data/p1/p2 -> data/n4/p1/p2 failed. no such file or directory

Directories data/p1 (inode 263) and data/p1/p2 (inode 264) in the parent
snapshot are both orphanized during the incremental send, and as soon as
data/p1 is orphanized, we must make sure that when orphanizing data/p1/p2
we use a source path of o263-6-o/p2 for the rename operation instead of
the old path data/p1/p2 (the one before the orphanization of inode 263).

A test case for xfstests follows soon.

Reported-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:51 -07:00
Filipe Manana 2f1f465ae6 Btrfs: send, don't leave without decrementing clone root's send_progress
If the clone root was not readonly or the dead flag was set on it, we were
leaving without decrementing the root's send_progress counter (and before
we just incremented it). If a concurrent snapshot deletion was in progress
and ended up being aborted, it would be impossible to later attempt to
delete again the snapshot, since the root's send_in_progress counter could
never go back to 0.

We were also setting clone_sources_to_rollback to i + 1 too early - if we
bailed out because the clone root we got is not readonly or flagged as dead
we ended up later derreferencing a null pointer because we didn't assign
the clone root to sctx->clone_roots[i].root:

		for (i = 0; sctx && i < clone_sources_to_rollback; i++)
			btrfs_root_dec_send_in_progress(
					sctx->clone_roots[i].root);

So just don't increment the send_in_progress counter if the root is readonly
or flagged as dead.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:51 -07:00
Filipe Manana 5cc2b17e80 Btrfs: send, add missing check for dead clone root
After we locked the root's root item, a concurrent snapshot deletion
call might have set the dead flag on it. So check if the dead flag
is set and abort if it is, just like we do for the parent root.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:51 -07:00
Filipe Manana 4f764e5153 Btrfs: remove deleted xattrs on fsync log replay
If we deleted xattrs from a file and fsynced the file, after a log replay
the xattrs would remain associated to the file. This was an unexpected
behaviour and differs from what other filesystems do, such as for example
xfs and ext3/4.

Fix this by, on fsync log replay, check if every xattr in the fs/subvol
tree (that belongs to a logged inode) has a matching xattr in the log,
and if it does not, delete it from the fs/subvol tree. This is a similar
approach to what we do for dentries when we replay a directory from the
fsync log.

This issue is trivial to reproduce, and the following excerpt from my
test for xfstests triggers the issue:

  _crash_and_mount()
  {
       # Simulate a crash/power loss.
       _load_flakey_table $FLAKEY_DROP_WRITES
       _unmount_flakey
       _load_flakey_table $FLAKEY_ALLOW_WRITES
       _mount_flakey
  }

  rm -f $seqres.full

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create out test file and add 3 xattrs to it.
  touch $SCRATCH_MNT/foobar
  $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar
  $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar
  $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar

  # Make sure everything is durably persisted.
  sync

  # Now delete the second xattr and fsync the inode.
  $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar

  _crash_and_mount

  # After the fsync log is replayed, the file should have only 2 xattrs, the ones
  # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file
  # with the 3 xattrs that we had before deleting the second one and fsyncing the
  # file.
  echo "xattr names and values after first fsync log replay:"
  $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch

  # Now write some data to our file, fsync it, remove the first xattr, add a new
  # hard link to our file and commit the fsync log by fsyncing some other new
  # file. This is to verify that after log replay our first xattr does not exist
  # anymore.
  echo "hello world!" >> $SCRATCH_MNT/foobar
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar
  $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar
  ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link
  touch $SCRATCH_MNT/qwerty
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty

  _crash_and_mount

  # Now only the xattr with name user.attr3 should be set in our file.
  echo "xattr names and values after second fsync log replay:"
  $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch

  status=0
  exit

The expected golden output, which is produced with this patch applied or
when testing against xfs or ext3/4, is:

  xattr names and values after first fsync log replay:
  # file: SCRATCH_MNT/foobar
  user.attr1="val1"
  user.attr3="val3"

  xattr names and values after second fsync log replay:
  # file: SCRATCH_MNT/foobar
  user.attr3="val3"

Without this patch applied, the output is:

  xattr names and values after first fsync log replay:
  # file: SCRATCH_MNT/foobar
  user.attr1="val1"
  user.attr2="val2"
  user.attr3="val3"

  xattr names and values after second fsync log replay:
  # file: SCRATCH_MNT/foobar
  user.attr1="val1"
  user.attr2="val2"
  user.attr3="val3"

A patch with a test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26 17:55:51 -07:00
Christoph Hellwig e2e40f2c1e fs: move struct kiocb to fs.h
struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25 20:28:11 -04:00
Chris Mason fc4c3c872f Merge branch 'cleanups-post-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1
Signed-off-by: Chris Mason <clm@fb.com>

Conflicts:
	fs/btrfs/disk-io.c
2015-03-25 10:52:48 -07:00
Chris Mason 9deed229fa Merge branch 'cleanups-for-4.1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1 2015-03-25 10:43:16 -07:00
Linus Torvalds 521d474631 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Most of these are fixing extent reservation accounting, or corners
  with tree writeback during commit.

  Josef's set does add a test, which isn't strictly a fix, but it'll
  keep us from making this same mistake again"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix outstanding_extents accounting in DIO
  Btrfs: add sanity test for outstanding_extents accounting
  Btrfs: just free dummy extent buffers
  Btrfs: account merges/splits properly
  Btrfs: prepare block group cache before writing
  Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
  Btrfs: account for the correct number of extents for delalloc reservations
  Btrfs: fix merge delalloc logic
  Btrfs: fix comp_oper to get right order
  Btrfs: catch transaction abortion after waiting for it
  btrfs: fix sizeof format specifier in btrfs_check_super_valid()
2015-03-21 10:53:37 -07:00
Josef Bacik e1cbbfa5f5 Btrfs: fix outstanding_extents accounting in DIO
We are keeping track of how many extents we need to reserve properly based on
the amount we want to write, but we were still incrementing outstanding_extents
if we wrote less than what we requested.  This isn't quite right since we will
be limited to our max extent size.  So instead lets do something horrible!  Keep
track of how many outstanding_extents we reserved, and decrement each time we
allocate an extent.  If we use our entire reserve make sure to jack up
outstanding_extents on the inode so the accounting works out properly.  Thanks,

Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
2015-03-17 16:36:35 -04:00
Josef Bacik 6a3891c551 Btrfs: add sanity test for outstanding_extents accounting
I introduced a regression wrt outstanding_extents accounting.  These are tricky
areas that aren't easily covered by xfstests as we could change MAX_EXTENT_SIZE
at any time.  So add sanity tests to cover the various conditions that are
tricky in order to make sure we don't introduce regressions in the future.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
2015-03-17 16:36:31 -04:00
Josef Bacik bcb7e449ec Btrfs: just free dummy extent buffers
If we fail during our sanity tests we could get NULL deref's because we unload
the module before the dummy extent buffers are free'd via RCU.  So check for
this case and just free the things directly.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
2015-03-17 16:30:18 -04:00
Josef Bacik ba11721355 Btrfs: account merges/splits properly
My fix

Btrfs: fix merge delalloc logic

only fixed half of the problems, it didn't fix the case where we have two large
extents on either side and then join them together with a new small extent.  We
need to instead keep track of how many extents we have accounted for with each
side of the new extent, and then see how many extents we need for the new large
extent.  If they match then we know we need to keep our reservation, otherwise
we need to drop our reservation.  This shows up with a case like this

[BTRFS_MAX_EXTENT_SIZE+4K][4K HOLE][BTRFS_MAX_EXTENT_SIZE+4K]

Previously the logic would have said that the number extents required for the
new size (3) is larger than the number of extents required for the largest side
(2) therefore we need to keep our reservation.  But this isn't the case, since
both sides require a reservation of 2 which leads to 4 for the whole range
currently reserved, but we only need 3, so we need to drop one of the
reservations.  The same problem existed for splits, we'd think we only need 3
extents when creating the hole but in reality we need 4.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
2015-03-17 16:28:21 -04:00
Josef Bacik dcdf7f6ddb Btrfs: prepare block group cache before writing
Writing the block group cache will modify the extent tree quite a bit because it
truncates the old space cache and pre-allocates new stuff.  To try and cut down
on the churn lets do the setup dance first, then later on hopefully we can avoid
looping with newly dirtied roots.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
2015-03-17 10:56:55 -04:00
Josef Bacik ea526d1899 Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
Dave could hit this assert consistently running btrfs/078.  This is because
when we update the block groups we could truncate the free space, which would
try to delete the csums for that range and dirty the csum root.  For this to
happen we have to have already written out the csum root so it's kind of hard to
hit this case.  This patch fixes this by changing the logic to only write the
dirty block groups if the dirty_cowonly_roots list is empty.  This will get us
the same effect as before since we add the extent root last, and will cover the
case that we dirty some other root again but not the extent root.  Thanks,

Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:47:04 -07:00
Josef Bacik 6a41dd0922 Btrfs: account for the correct number of extents for delalloc reservations
Direct IO can easily pass in an buffer that is greater than
BTRFS_MAX_EXTENT_SIZE, so take this into account when reserving extents in the
delalloc reservation code.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:46:59 -07:00
Josef Bacik 8461a3de77 Btrfs: fix merge delalloc logic
My patch to properly count outstanding extents wrt MAX_EXTENT_SIZE introduced a
regression when re-dirtying already dirty areas.  We have logic in split to make
sure we are taking the largest space into account but didn't have it for merge,
so it was sometimes making us think we were turning a tiny extent into a huge
extent, when in reality we already had a huge extent and needed to use the other
side in our logic.  This fixes the regression that was reported by a user on
list.  Thanks,

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:46:59 -07:00
Liu Bo 48da5f0a4c Btrfs: fix comp_oper to get right order
Case (oper1->seq > oper2->seq) should differ with case (oper1->seq < oper2->seq).

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:46:59 -07:00
Liu Bo b4924a0fa1 Btrfs: catch transaction abortion after waiting for it
This problem is uncovered by a test case: http://patchwork.ozlabs.org/patch/244297.

Fsync() can report success when it actually doesn't.  When we
have several threads running fsync() at the same tiem and in one fsync() we
get a transaction abortion due to some problems(in the test case it's disk
failures), and other fsync()s may return successfully which makes userspace
programs think that data is now safely flushed into disk.

It's because that after fsyncs() fail btrfs_sync_log() due to disk failures,
they get to try btrfs_commit_transaction() where it finds that there is
already a transaction being committed, and they'll just call wait_for_commit()
and return.  Note that we actually check "trans->aborted" in btrfs_end_transaction,
but it's likely that the error message is still not yet throwed out and only after
wait_for_commit() we're sure whether the transaction is committed successfully.

This add the necessary check and it now passes the test.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:38:23 -07:00
Fabian Frederick d22071293f btrfs: fix sizeof format specifier in btrfs_check_super_valid()
This patch fixes mips compilation warning:

fs/btrfs/disk-io.c: In function 'btrfs_check_super_valid':
fs/btrfs/disk-io.c:3927:21: warning: format '%lu' expects argument
of type 'long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-13 13:38:22 -07:00
Linus Torvalds 84399bb075 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Outside of misc fixes, Filipe has a few fsync corners and we're
  pulling in one more of Josef's fixes from production use here"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.
  Btrfs: fix data loss in the fast fsync path
  Btrfs: remove extra run_delayed_refs in update_cowonly_root
  Btrfs: incremental send, don't rename a directory too soon
  btrfs: fix lost return value due to variable shadowing
  Btrfs: do not ignore errors from btrfs_lookup_xattr in do_setxattr
  Btrfs: fix off-by-one logic error in btrfs_realloc_node
  Btrfs: add missing inode update when punching hole
  Btrfs: abort the transaction if we fail to update the free space cache inode
  Btrfs: fix fsync race leading to ordered extent memory leaks
2015-03-06 13:52:54 -08:00
Quentin Casasnovas dd9ef135e3 Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.
Improper arithmetics when calculting the address of the extended ref could
lead to an out of bounds memory read and kernel panic.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
cc: stable@vger.kernel.org # v3.7+
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-05 17:28:33 -08:00
Filipe Manana 3a8b36f378 Btrfs: fix data loss in the fast fsync path
When using the fast file fsync code path we can miss the fact that new
writes happened since the last file fsync and therefore return without
waiting for the IO to finish and write the new extents to the fsync log.

Here's an example scenario where the fsync will miss the fact that new
file data exists that wasn't yet durably persisted:

1. fs_info->last_trans_committed == N - 1 and current transaction is
   transaction N (fs_info->generation == N);

2. do a buffered write;

3. fsync our inode, this clears our inode's full sync flag, starts
   an ordered extent and waits for it to complete - when it completes
   at btrfs_finish_ordered_io(), the inode's last_trans is set to the
   value N (via btrfs_update_inode_fallback -> btrfs_update_inode ->
   btrfs_set_inode_last_trans);

4. transaction N is committed, so fs_info->last_trans_committed is now
   set to the value N and fs_info->generation remains with the value N;

5. do another buffered write, when this happens btrfs_file_write_iter
   sets our inode's last_trans to the value N + 1 (that is
   fs_info->generation + 1 == N + 1);

6. transaction N + 1 is started and fs_info->generation now has the
   value N + 1;

7. transaction N + 1 is committed, so fs_info->last_trans_committed
   is set to the value N + 1;

8. fsync our inode - because it doesn't have the full sync flag set,
   we only start the ordered extent, we don't wait for it to complete
   (only in a later phase) therefore its last_trans field has the
   value N + 1 set previously by btrfs_file_write_iter(), and so we
   have:

       inode->last_trans <= fs_info->last_trans_committed
           (N + 1)              (N + 1)

   Which made us not log the last buffered write and exit the fsync
   handler immediately, returning success (0) to user space and resulting
   in data loss after a crash.

This can actually be triggered deterministically and the following excerpt
from a testcase I made for xfstests triggers the issue. It moves a dummy
file across directories and then fsyncs the old parent directory - this
is just to trigger a transaction commit, so moving files around isn't
directly related to the issue but it was chosen because running 'sync' for
example does more than just committing the current transaction, as it
flushes/waits for all file data to be persisted. The issue can also happen
at random periods, since the transaction kthread periodicaly commits the
current transaction (about every 30 seconds by default).
The body of the test is:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create our main test file 'foo', the one we check for data loss.
  # By doing an fsync against our file, it makes btrfs clear the 'needs_full_sync'
  # bit from its flags (btrfs inode specific flags).
  $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" \
                  -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io

  # Now create one other file and 2 directories. We will move this second file
  # from one directory to the other later because it forces btrfs to commit its
  # currently open transaction if we fsync the old parent directory. This is
  # necessary to trigger the data loss bug that affected btrfs.
  mkdir $SCRATCH_MNT/testdir_1
  touch $SCRATCH_MNT/testdir_1/bar
  mkdir $SCRATCH_MNT/testdir_2

  # Make sure everything is durably persisted.
  sync

  # Write more 8Kb of data to our file.
  $XFS_IO_PROG -c "pwrite -S 0xbb 8K 8K" $SCRATCH_MNT/foo | _filter_xfs_io

  # Move our 'bar' file into a new directory.
  mv $SCRATCH_MNT/testdir_1/bar $SCRATCH_MNT/testdir_2/bar

  # Fsync our first directory. Because it had a file moved into some other
  # directory, this made btrfs commit the currently open transaction. This is
  # a condition necessary to trigger the data loss bug.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir_1

  # Now fsync our main test file. If the fsync succeeds, we expect the 8Kb of
  # data we wrote previously to be persisted and available if a crash happens.
  # This did not happen with btrfs, because of the transaction commit that
  # happened when we fsynced the parent directory.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # Now check that all data we wrote before are available.
  echo "File content after log replay:"
  od -t x1 $SCRATCH_MNT/foo

  status=0
  exit

The expected golden output for the test, which is what we get with this
fix applied (or when running against ext3/4 and xfs), is:

  wrote 8192/8192 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  wrote 8192/8192 bytes at offset 8192
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  File content after log replay:
  0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
  *
  0020000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb
  *
  0040000

Without this fix applied, the output shows the test file does not have
the second 8Kb extent that we successfully fsynced:

  wrote 8192/8192 bytes at offset 0
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  wrote 8192/8192 bytes at offset 8192
  XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
  File content after log replay:
  0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
  *
  0020000

So fix this by skipping the fsync only if we're doing a full sync and
if the inode's last_trans is <= fs_info->last_trans_committed, or if
the inode is already in the log. Also remove setting the inode's
last_trans in btrfs_file_write_iter since it's useless/unreliable.

Also because btrfs_file_write_iter no longer sets inode->last_trans to
fs_info->generation + 1, don't set last_trans to 0 if we bail out and don't
bail out if last_trans is 0, otherwise something as simple as the following
example wouldn't log the second write on the last fsync:

  1. write to file

  2. fsync file

  3. fsync file
       |--> btrfs_inode_in_log() returns true and it set last_trans to 0

  4. write to file
       |--> btrfs_file_write_iter() no longers sets last_trans, so it
            remained with a value of 0
  5. fsync
       |--> inode->last_trans == 0, so it bails out without logging the
            second write

A test case for xfstests will be sent soon.

CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-05 17:28:32 -08:00
Josef Bacik f5c0a12280 Btrfs: remove extra run_delayed_refs in update_cowonly_root
This got added with my dirty_bgs patch, it's not needed.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-05 17:28:30 -08:00
David Sterba 258ece0212 btrfs: remove shadowing variables in __btrfs_map_block
1) We can safely use the function's 'i'. Fixes warning

fs/btrfs/volumes.c:5257:7: warning: declaration of 'i' shadows a previous local
fs/btrfs/volumes.c:4951:6: warning: shadowed declaration is here

2) A local variable duplicates name of an argument, we can use the value
directly. Fixes warning

fs/btrfs/volumes.c:5433:8: warning: declaration of 'length' shadows a parameter
fs/btrfs/volumes.c:4935:27: warning: shadowed declaration is here

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:35 +01:00
David Sterba 093adbcedf btrfs: switch helper macros to static inlines in sysfs.h
The conversion macros use nested container_of that leads to a warning

fs/btrfs/sysfs.c: In function 'btrfs_feature_visible':
fs/btrfs/sysfs.c:183:8: warning: declaration of '__mptr' shadows a previous local
fs/btrfs/sysfs.c:183:8: warning: shadowed declaration is here

Use of functions will add proper type checking.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:02 +01:00
David Sterba 9d644a623e btrfs: cleanup, use correct type in div_u64_rem
div_u64_rem expects u32 for divisior and reminder.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:01 +01:00
David Sterba 47c5713f47 btrfs: replace remaining do_div calls with div_u64 variants
Switch to div_u64_rem that does type checking and has more obvious
semantics than do_div.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:01 +01:00
David Sterba b8b93addde btrfs: cleanup 64bit/32bit divs, provably bounded values
The divisor is derived from nodesize or PAGE_SIZE, fits into 32bit type.
Get rid of a few more do_div instances.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:00 +01:00
David Sterba 3284da7b7b btrfs: use explicit initializer for seq_elem
Using {} as initializer for struct seq_elem does not properly initialize
the list_head member, but it currently works because it gets set through
btrfs_get_tree_mod_seq if 'seq' is 0.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:59 +01:00
David Sterba f64c7b12f8 btrfs: remove shadowing variables in __btrfs_buffered_write
There are lockstart and lockend defined in the function and not used
after their duplicate definition scope ends, it's safe to reuse them.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:58 +01:00
David Sterba 31e818fe73 btrfs: cleanup, use kmalloc_array/kcalloc array helpers
Convert kmalloc(nr * size, ..) to kmalloc_array that does additional
overflow checks, the zeroing variant is kcalloc.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:58 +01:00
David Sterba f8c269d722 btrfs: cleanup 64bit/32bit divs, compile time constants
Switch to div_u64 if the divisor is a numeric constant or sum of
sizeof()s. We can remove a few instances of do_div that has the hidden
semtantics of changing the 1st argument.

Small power-of-two divisors are converted to bitshifts, large values are
kept intact for clarity.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:57 +01:00
David Sterba 351810c1d2 btrfs: use cond_resched_lock where possible
Clean the opencoded variant, cond_resched_lock also checks the lock for
contention so it might help in some cases that were not covered by
simple need_resched().

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:56 +01:00
David Sterba 853d8ec4b2 btrfs: need_resched not needed with cond_resched
Cleanup, no special reason to do

if (need_resched())
        cond_resched();

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:55 +01:00
Filipe Manana 84471e2429 Btrfs: incremental send, don't rename a directory too soon
There's one more case where we can't issue a rename operation for a
directory as soon as we process it. We used to delay directory renames
only if they have some ancestor directory with a higher inode number
that got renamed too, but there's another case where we need to delay
the rename too - when a directory A is renamed to the old name of a
directory B but that directory B has its rename delayed because it
has now (in the send root) an ancestor with a higher inode number that
was renamed. If we don't delay the directory rename in this case, the
receiving end of the send stream will attempt to rename A to the old
name of B before B got renamed to its new name, which results in a
"directory not empty" error. So fix this by delaying directory renames
for this case too.

Steps to reproduce:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/a
  $ mkdir /mnt/b
  $ mkdir /mnt/c
  $ touch /mnt/a/file

  $ btrfs subvolume snapshot -r /mnt /mnt/snap1

  $ mv /mnt/c /mnt/x
  $ mv /mnt/a /mnt/x/y
  $ mv /mnt/b /mnt/a

  $ btrfs subvolume snapshot -r /mnt /mnt/snap2

  $ btrfs send /mnt/snap1 -f /tmp/1.send
  $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.send

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt2
  $ btrfs receive /mnt2 -f /tmp/1.send
  $ btrfs receive /mnt2 -f /tmp/2.send
  ERROR: rename b -> a failed. Directory not empty

A test case for xfstests follows soon.

Reported-by: Ames Cornish <ames@cornishes.net>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:45 -08:00
David Sterba 1932b7be97 btrfs: fix lost return value due to variable shadowing
A block-local variable stores error code but btrfs_get_blocks_direct may
not return it in the end as there's a ret defined in the function scope.

CC: <stable@vger.kernel.org>	# 3.6+
Fixes: d187663ef2 ("Btrfs: lock extents as we map them in DIO")
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:45 -08:00
Filipe Manana 5cdf83edb8 Btrfs: do not ignore errors from btrfs_lookup_xattr in do_setxattr
The return value from btrfs_lookup_xattr() can be a pointer encoding an
error, therefore deal with it. This fixes commit 5f5bc6b1e2
("Btrfs: make xattr replace operations atomic").

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:45 -08:00
Filipe Manana 5dfe2be7ea Btrfs: fix off-by-one logic error in btrfs_realloc_node
The end_slot variable actually matches the number of pointers in the
node and not the last slot (which is 'nritems - 1'). Therefore in order
to check that the current slot in the for loop doesn't match the last
one, the correct logic is to check if 'i' is less than 'end_slot - 1'
and not 'end_slot - 2'.

Fix this and set end_slot to be 'nritems - 1', as it's less confusing
since the variable name implies it's inclusive rather then exclusive.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:45 -08:00
Filipe Manana e8c1c76e80 Btrfs: add missing inode update when punching hole
When punching a file hole if we endup only zeroing parts of a page,
because the start offset isn't a multiple of the sector size or the
start offset and length fall within the same page, we were not updating
the inode item. This prevented an fsync from doing anything, if no other
file changes happened in the current transaction, because the fields
in btrfs_inode used to check if the inode needs to be fsync'ed weren't
updated.

This issue is easy to reproduce and the following excerpt from the
xfstest case I made shows how to trigger it:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create our test file.
  $XFS_IO_PROG -f -c "pwrite -S 0x22 -b 16K 0 16K" \
      $SCRATCH_MNT/foo | _filter_xfs_io

  # Fsync the file, this makes btrfs update some btrfs inode specific fields
  # that are used to track if the inode needs to be written/updated to the fsync
  # log or not. After this fsync, the new values for those fields indicate that
  # a subsequent fsync does not need to touch the fsync log.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

  # Force a commit of the current transaction. After this point, any operation
  # that modifies the data or metadata of our file, should update those fields in
  # the btrfs inode with values that make the next fsync operation write to the
  # fsync log.
  sync

  # Punch a hole in our file. This small range affects only 1 page.
  # This made the btrfs hole punching implementation write only some zeroes in
  # one page, but it did not update the btrfs inode fields used to determine if
  # the next fsync needs to write to the fsync log.
  $XFS_IO_PROG -c "fpunch 8000 4K" $SCRATCH_MNT/foo

  # Another variation of the previously mentioned case.
  $XFS_IO_PROG -c "fpunch 15000 100" $SCRATCH_MNT/foo

  # Now fsync the file. This was a no-operation because the previous hole punch
  # operation didn't update the inode's fields mentioned before, so they remained
  # with the values they had after the first fsync - that is, they indicate that
  # it is not needed to write to fsync log.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

  echo "File content before:"
  od -t x1 $SCRATCH_MNT/foo

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  # Enable writes and mount the fs. This makes the fsync log replay code run.
  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # Because the last fsync didn't do anything, here the file content matched what
  # it was after the first fsync, before the holes were punched, and not what it
  # was after the holes were punched.
  echo "File content after:"
  od -t x1 $SCRATCH_MNT/foo

This issue has been around since 2012, when the punch hole implementation
was added, commit 2aaa665581 ("Btrfs: add hole punching").

A test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:44 -08:00
Josef Bacik 0c0ef4bc84 Btrfs: abort the transaction if we fail to update the free space cache inode
Our gluster boxes were hitting a problem where they'd run out of space when
updating the block group cache and therefore wouldn't be able to update the free
space inode.  This is a problem because this is how we invalidate the cache and
protect ourselves from errors further down the stack, so if this fails we have
to abort the transaction so we make sure we don't end up with stale free space
cache.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:44 -08:00
Filipe Manana 4d884fceaa Btrfs: fix fsync race leading to ordered extent memory leaks
We can have multiple fsync operations against the same file during the
same transaction and they can collect the same ordered extents while they
don't complete (still accessible from the inode's ordered tree). If this
happens, those ordered extents will never get their reference counts
decremented to 0, leading to memory leaks and inode leaks (an iput for an
ordered extent's inode is scheduled only when the ordered extent's refcount
drops to 0). The following sequence diagram explains this race:

         CPU 1                                         CPU 2

btrfs_sync_file()

                                                 btrfs_sync_file()

  mutex_lock(inode->i_mutex)
  btrfs_log_inode()
    btrfs_get_logged_extents()
      --> collects ordered extent X
      --> increments ordered
          extent X's refcount
    btrfs_submit_logged_extents()
  mutex_unlock(inode->i_mutex)

                                                   mutex_lock(inode->i_mutex)
  btrfs_sync_log()
     btrfs_wait_logged_extents()
       --> list_del_init(&ordered->log_list)
                                                     btrfs_log_inode()
                                                       btrfs_get_logged_extents()
                                                         --> Adds ordered extent X
                                                             to logged_list because
                                                             at this point:
                                                             list_empty(&ordered->log_list)
                                                             && test_bit(BTRFS_ORDERED_LOGGED,
                                                                         &ordered->flags) == 0
                                                         --> Increments ordered extent
                                                             X's refcount
       --> check if ordered extent's io is
           finished or not, start it if
           necessary and wait for it to finish
       --> sets bit BTRFS_ORDERED_LOGGED
           on ordered extent X's flags
           and adds it to trans->ordered
  btrfs_sync_log() finishes

                                                       btrfs_submit_logged_extents()
                                                     btrfs_log_inode() finishes
                                                   mutex_unlock(inode->i_mutex)

btrfs_sync_file() finishes

                                                   btrfs_sync_log()
                                                      btrfs_wait_logged_extents()
                                                        --> Sees ordered extent X has the
                                                            bit BTRFS_ORDERED_LOGGED set in
                                                            its flags
                                                        --> X's refcount is untouched
                                                   btrfs_sync_log() finishes

                                                 btrfs_sync_file() finishes

btrfs_commit_transaction()
  --> called by transaction kthread for e.g.
  btrfs_wait_pending_ordered()
    --> waits for ordered extent X to
        complete
    --> decrements ordered extent X's
        refcount by 1 only, corresponding
        to the increment done by the fsync
        task ran by CPU 1

In the scenario of the above diagram, after the transaction commit,
the ordered extent will remain with a refcount of 1 forever, leaking
the ordered extent structure and preventing the i_count of its inode
from ever decreasing to 0, since the delayed iput is scheduled only
when the ordered extent's refcount drops to 0, preventing the inode
from ever being evicted by the VFS.

Fix this by using the flag BTRFS_ORDERED_LOGGED differently. Use it to
mean that an ordered extent is already being processed by an fsync call,
which will attach it to the current transaction, preventing it from being
collected by subsequent fsync operations against the same inode.

This race was introduced with the following change (added in 3.19 and
backported to stable 3.18 and 3.17):

  Btrfs: make sure logged extents complete in the current transaction V3
  commit 50d9aa99bd

I ran into this issue while running xfstests/generic/113 in a loop, which
failed about 1 out of 10 runs with the following warning in dmesg:

[ 2612.440038] WARNING: CPU: 4 PID: 22057 at fs/btrfs/disk-io.c:3558 free_fs_root+0x36/0x133 [btrfs]()
[ 2612.442810] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop processor parport_pc parport psmouse therma
l_sys i2c_piix4 serio_raw pcspkr evdev microcode button i2c_core ext4 crc16 jbd2 mbcache sd_mod sg sr_mod cdrom virtio_scsi ata_generic virtio_pci ata_piix virtio_ring libata virtio flo
ppy e1000 scsi_mod [last unloaded: btrfs]
[ 2612.452711] CPU: 4 PID: 22057 Comm: umount Tainted: G        W      3.19.0-rc5-btrfs-next-4+ #1
[ 2612.454921] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[ 2612.457709]  0000000000000009 ffff8801342c3c78 ffffffff8142425e ffff88023ec8f2d8
[ 2612.459829]  0000000000000000 ffff8801342c3cb8 ffffffff81045308 ffff880046460000
[ 2612.461564]  ffffffffa036da56 ffff88003d07b000 ffff880046460000 ffff880046460068
[ 2612.463163] Call Trace:
[ 2612.463719]  [<ffffffff8142425e>] dump_stack+0x4c/0x65
[ 2612.464789]  [<ffffffff81045308>] warn_slowpath_common+0xa1/0xbb
[ 2612.466026]  [<ffffffffa036da56>] ? free_fs_root+0x36/0x133 [btrfs]
[ 2612.467247]  [<ffffffff810453c5>] warn_slowpath_null+0x1a/0x1c
[ 2612.468416]  [<ffffffffa036da56>] free_fs_root+0x36/0x133 [btrfs]
[ 2612.469625]  [<ffffffffa036f2a7>] btrfs_drop_and_free_fs_root+0x93/0x9b [btrfs]
[ 2612.471251]  [<ffffffffa036f353>] btrfs_free_fs_roots+0xa4/0xd6 [btrfs]
[ 2612.472536]  [<ffffffff8142612e>] ? wait_for_completion+0x24/0x26
[ 2612.473742]  [<ffffffffa0370bbc>] close_ctree+0x1f3/0x33c [btrfs]
[ 2612.475477]  [<ffffffff81059d1d>] ? destroy_workqueue+0x148/0x1ba
[ 2612.476695]  [<ffffffffa034e3da>] btrfs_put_super+0x19/0x1b [btrfs]
[ 2612.477911]  [<ffffffff81153e53>] generic_shutdown_super+0x73/0xef
[ 2612.479106]  [<ffffffff811540e2>] kill_anon_super+0x13/0x1e
[ 2612.480226]  [<ffffffffa034e1e3>] btrfs_kill_super+0x17/0x23 [btrfs]
[ 2612.481471]  [<ffffffff81154307>] deactivate_locked_super+0x3b/0x50
[ 2612.482686]  [<ffffffff811547a7>] deactivate_super+0x3f/0x43
[ 2612.483791]  [<ffffffff8116b3ed>] cleanup_mnt+0x59/0x78
[ 2612.484842]  [<ffffffff8116b44c>] __cleanup_mnt+0x12/0x14
[ 2612.485900]  [<ffffffff8105d019>] task_work_run+0x8f/0xbc
[ 2612.486960]  [<ffffffff810028d8>] do_notify_resume+0x5a/0x6b
[ 2612.488083]  [<ffffffff81236e5b>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[ 2612.489333]  [<ffffffff8142a17f>] int_signal+0x12/0x17
[ 2612.490353] ---[ end trace 54a960a6bdcb8d93 ]---
[ 2612.557253] VFS: Busy inodes after unmount of sdb. Self-destruct in 5 seconds.  Have a nice day...

Kmemleak confirmed the ordered extent leak (and btrfs inode specific
structures such as delayed nodes):

$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff880154290db0 (size 576):
  comm "btrfsck", pid 21980, jiffies 4295542503 (age 1273.412s)
  hex dump (first 32 bytes):
    01 40 00 00 01 00 00 00 b0 1d f1 4e 01 88 ff ff  .@.........N....
    00 00 00 00 00 00 00 00 c8 0d 29 54 01 88 ff ff  ..........)T....
  backtrace:
    [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a
    [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83
    [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190
    [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac
    [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs]
    [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs]
    [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs]
    [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs]
    [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs]
    [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed
    [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa
    [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b
    [<ffffffff81429e92>] system_call_fastpath+0x12/0x17
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff88014ef11db0 (size 576):
  comm "rm", pid 22009, jiffies 4295542593 (age 1273.052s)
  hex dump (first 32 bytes):
    02 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 c8 1d f1 4e 01 88 ff ff  ...........N....
  backtrace:
    [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a
    [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83
    [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190
    [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac
    [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs]
    [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs]
    [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs]
    [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs]
    [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs]
    [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed
    [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa
    [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b
    [<ffffffff81429e92>] system_call_fastpath+0x12/0x17
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff8800336feda8 (size 584):
  comm "aio-stress", pid 22031, jiffies 4295543006 (age 1271.400s)
  hex dump (first 32 bytes):
    00 40 3e 00 00 00 00 00 00 00 8f 42 00 00 00 00  .@>........B....
    00 00 01 00 00 00 00 00 00 00 01 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8114eb34>] create_object+0x172/0x29a
    [<ffffffff8141d790>] kmemleak_alloc+0x25/0x41
    [<ffffffff81141ae6>] kmemleak_alloc_recursive.constprop.52+0x16/0x18
    [<ffffffff81145288>] kmem_cache_alloc+0xf7/0x198
    [<ffffffffa0389243>] __btrfs_add_ordered_extent+0x43/0x309 [btrfs]
    [<ffffffffa038968b>] btrfs_add_ordered_extent_dio+0x12/0x14 [btrfs]
    [<ffffffffa03810e2>] btrfs_get_blocks_direct+0x3ef/0x571 [btrfs]
    [<ffffffff81181349>] do_blockdev_direct_IO+0x62a/0xb47
    [<ffffffff8118189a>] __blockdev_direct_IO+0x34/0x36
    [<ffffffffa03776e5>] btrfs_direct_IO+0x16a/0x1e8 [btrfs]
    [<ffffffff81100373>] generic_file_direct_write+0xb8/0x12d
    [<ffffffffa038615c>] btrfs_file_write_iter+0x24b/0x42f [btrfs]
    [<ffffffff8118bb0d>] aio_run_iocb+0x2b7/0x32e
    [<ffffffff8118c99a>] do_io_submit+0x26e/0x2ff
    [<ffffffff8118ca3b>] SyS_io_submit+0x10/0x12
    [<ffffffff81429e92>] system_call_fastpath+0x12/0x17

CC: <stable@vger.kernel.org> # 3.19, 3.18 and 3.17
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02 14:04:44 -08:00
Linus Torvalds 7dac5cb1bc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "I'm still testing more fixes, but I wanted to get out the fix for the
  btrfs raid5/6 memory corruption I mentioned in my merge window pull"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix allocation size calculations in alloc_btrfs_bio
2015-02-26 10:34:24 -08:00
Linus Torvalds be5e6616dd Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted stuff from this cycle.  The big ones here are multilayer
  overlayfs from Miklos and beginning of sorting ->d_inode accesses out
  from David"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (51 commits)
  autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation
  procfs: fix race between symlink removals and traversals
  debugfs: leave freeing a symlink body until inode eviction
  Documentation/filesystems/Locking: ->get_sb() is long gone
  trylock_super(): replacement for grab_super_passive()
  fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions
  Cachefiles: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions
  VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
  SELinux: Use d_is_positive() rather than testing dentry->d_inode
  Smack: Use d_is_positive() rather than testing dentry->d_inode
  TOMOYO: Use d_is_dir() rather than d_inode and S_ISDIR()
  Apparmor: Use d_is_positive/negative() rather than testing dentry->d_inode
  Apparmor: mediated_filesystem() should use dentry->d_sb not inode->i_sb
  VFS: Split DCACHE_FILE_TYPE into regular and special types
  VFS: Add a fallthrough flag for marking virtual dentries
  VFS: Add a whiteout dentry type
  VFS: Introduce inode-getting helpers for layered/unioned fs environments
  Infiniband: Fix potential NULL d_inode dereference
  posix_acl: fix reference leaks in posix_acl_create
  autofs4: Wrong format for printing dentry
  ...
2015-02-22 17:42:14 -08:00
David Howells e36cb0b89c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:38:41 -05:00
Chris Mason e57cf21e97 Btrfs: fix allocation size calculations in alloc_btrfs_bio
Since commit 8e5cfb55d3 (Btrfs: Make raid_map array be inlined in
btrfs_bio structure), the raid map array is allocated along with the
btrfs bio in alloc_btrfs_bio.  The calculation used to decide how much
we need to allocate was using the wrong parameter passed into the
allocation function.

The passed in real_stripes will be zero if a target replace operation
is not currently running.  We want to use total_stripes instead.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: David Sterba <dsterba@suse.cz>
Tested-by: David Sterba <dsterba@suse.cz>
2015-02-20 06:55:15 -08:00
Linus Torvalds 2b9fb532d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "This pull is mostly cleanups and fixes:

   - The raid5/6 cleanups from Zhao Lei fixup some long standing warts
     in the code and add improvements on top of the scrubbing support
     from 3.19.

   - Josef has round one of our ENOSPC fixes coming from large btrfs
     clusters here at FB.

   - Dave Sterba continues a long series of cleanups (thanks Dave), and
     Filipe continues hammering on corner cases in fsync and others

  This all was held up a little trying to track down a use-after-free in
  btrfs raid5/6.  It's not clear yet if this is just made easier to
  trigger with this pull or if its a new bug from the raid5/6 cleanups.
  Dave Sterba is the only one to trigger it so far, but he has a
  consistent way to reproduce, so we'll get it nailed shortly"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (68 commits)
  Btrfs: don't remove extents and xattrs when logging new names
  Btrfs: fix fsync data loss after adding hard link to inode
  Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group
  Btrfs: account for large extents with enospc
  Btrfs: don't set and clear delalloc for O_DIRECT writes
  Btrfs: only adjust outstanding_extents when we do a short write
  btrfs: Fix out-of-space bug
  Btrfs: scrub, fix sleep in atomic context
  Btrfs: fix scheduler warning when syncing log
  Btrfs: Remove unnecessary placeholder in btrfs_err_code
  btrfs: cleanup init for list in free-space-cache
  btrfs: delete chunk allocation attemp when setting block group ro
  btrfs: clear bio reference after submit_one_bio()
  Btrfs: fix scrub race leading to use-after-free
  Btrfs: add missing cleanup on sysfs init failure
  Btrfs: fix race between transaction commit and empty block group removal
  btrfs: add more checks to btrfs_read_sys_array
  btrfs: cleanup, rename a few variables in btrfs_read_sys_array
  btrfs: add checks for sys_chunk_array sizes
  btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize
  ...
2015-02-19 14:36:00 -08:00
David Sterba a4f3d2c4ef btrfs: cleanup, reduce temporary variables in btrfs_read_roots
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:47 +01:00
David Sterba 6f01105819 btrfs: use correct type for workqueue flags
Through all the local wrappers to alloc_workqueue, __alloc_workqueue_key
takes an unsigned int.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:47 +01:00
Eric Sandeen 4bbcaa648d btrfs: factor btrfs_read_roots() out of open_ctree()
Also, remove the two local variables create_uuid_tree
and check_uuid_tree; we can use the existence of
the uuid root and/or the RESCAN_UUID_TREE flag to
determine what action to take.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:46 +01:00
Eric Sandeen 63443bf54a btrfs: factor btrfs_replay_log() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:46 +01:00
Eric Sandeen 2a4581983f btrfs: factor btrfs_init_workqueues() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_workqueues]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:46 +01:00
Eric Sandeen f9e92e40b5 btrfs: factor btrfs_init_qgroup() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_qgroup]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:46 +01:00
Eric Sandeen ad6183680c btrfs: factor btrfs_init_dev_replace_locks() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_dev_replace_locks]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:46 +01:00
Eric Sandeen f37938e0e2 btrfs: factor btrfs_init_btree_inode() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_btree_inode]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Eric Sandeen 779a65a495 btrfs: factor btrfs_init_balance() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_balance]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Eric Sandeen 638aa7ed46 btrfs: factor btrfs_init_scrub() out of open_ctree()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[renamed to btrfs_init_scrub]
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Eric Sandeen 0489234077 btrfs: consistently use fs_info in close_ctree()
close_ctree() has a local fs_info var for convienience;
use it consistently.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Eric Sandeen 9eaed21ef9 btrfs: remove unused fs_info arg from btrfs_close_extra_devices()
The commit:
8dabb74 Btrfs: change core code of btrfs to support the
        device replace operations
added the fs_info argument, but never used it -
just remove it again.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Fabian Frederick 41d6b13ea7 btrfs: fix sizeof format specifier in btrfs_check_super_valid()
This patch fixes mips compilation warning:

fs/btrfs/disk-io.c: In function 'btrfs_check_super_valid':
fs/btrfs/disk-io.c:3927:21: warning: format '%lu' expects argument
of type 'long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Zhao Lei 08da757d3f btrfs: cleanup: use for() loop in btrfs_map_bio()
for() is obviously better in these code block, and remove noused
init-value to reduce about 6 bytes binary size.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Zhao Lei a688a04aab btrfs: remove unused chunk_tree argument in several functions
There functions include unused chunk_tree argument from the begining,
it is time to remove them and clean up relative code to prepare value
of this argument in caller.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Zhao Lei b9fd47cde5 btrfs: cleanup: remove no-used alloc_chunk in btrfs_check_data_free_space()
int alloc_chunk is never used in this function, remove it.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
David Sterba e8c9f18603 btrfs: constify structs with op functions or static definitions
There are some op tables that can be easily made const, similarly the
sysfs feature and raid tables. This is motivated by PaX CONSTIFY plugin.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Wang Shilong f749303bda Btrfs: switch to kvfree() helper
A new helper kvfree() in mm/utils.c will do this.

Signed-off-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:43 +01:00
Daniel Dressler 01d58472a8 Btrfs: disk-io: replace root args iff only fs_info used
This is the 3rd independent patch of a larger project to cleanup btrfs's
internal usage of btrfs_root. Many functions take btrfs_root only to
grab the fs_info struct.

By requiring a root these functions cause programmer overhead. That
these functions can accept any valid root is not obvious until
inspection.

This patch reduces the specificity of such functions to accept the
fs_info directly.

These patches can be applied independently and thus are not being
submitted as a patch series. There should be about 26 patches by the
project's completion. Each patch will cleanup between 1 and 34 functions
apiece.  Each patch covers a single file's functions.

This patch affects the following function(s):
  1) csum_tree_block
  2) csum_dirty_buffer
  3) check_tree_block_fsid
  4) btrfs_find_tree_block
  5) clean_tree_block

Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:43 +01:00
Daniel Dressler a585e94895 Btrfs: delayed-inode: replace root args iff only fs_info used
This is the second independent patch of a larger project to cleanup
btrfs's internal usage of btrfs_root. Many functions take btrfs_root
only to grab the fs_info struct.

By requiring a root these functions cause programmer overhead. That
these functions can accept any valid root is not obvious until
inspection.

This patch reduces the specificity of such functions to accept the
fs_info directly.

These patches can be applied independently and thus are not being
submitted as a patch series. There should be about 26 patches by the
project's completion. Each patch will cleanup between 1 and 34 functions
apiece.  Each patch covers a single file's functions.

This patch affects the following function(s):
  1) btrfs_wq_run_delayed_node

Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:43 +01:00
Daniel Dressler b7a0365ec7 Btrfs: ctree: reduce args where only fs_info used
This patch is part of a larger project to cleanup btrfs's internal usage
of struct btrfs_root. Many functions take btrfs_root only to grab a
pointer to fs_info.

This causes programmers to ponder which root can be passed. Since only
the fs_info is read affected functions can accept any root, except this
is only obvious upon inspection.

This patch reduces the specificty of such functions to accept the
fs_info directly.

This patch does not address the two functions in ctree.c (insert_ptr,
and split_item) which only use root for BUG_ONs in ctree.c

This patch affects the following functions:
  1) fixup_low_keys
  2) btrfs_set_item_key_safe

Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:43 +01:00
Filipe Manana a742994aa2 Btrfs: don't remove extents and xattrs when logging new names
If we are recording in the tree log that an inode has new names (new hard
links were added), we would drop items, belonging to the inode, that we
shouldn't:

1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime
   flags, we ended up dropping all the extent and xattr items that were
   previously logged. This was done only in memory, since logging a new
   name doesn't imply syncing the log;

2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime
   flags, we ended up dropping all the xattr items that were previously
   logged. Like the case before, this was done only in memory because
   logging a new name doesn't imply syncing the log.

This led to some surprises in scenarios such as the following:

1) write some extents to an inode;
2) fsync the inode;
3) truncate the inode or delete/modify some of its xattrs
4) add a new hard link for that inode
5) fsync some other file, to force the log tree to be durably persisted
6) power failure happens

The next time the fs is mounted, the fsync log replay code is executed,
and the resulting file doesn't have the content it had when the last fsync
against it was performed, instead if has a content matching what it had
when the last transaction commit happened.

So change the behaviour such that when a new name is logged, only the inode
item and reference items are processed.

This is easy to reproduce with the test I just made for xfstests, whose
main body is:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create our test file with some data.
  $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \
      $SCRATCH_MNT/foo | _filter_xfs_io

  # Make sure the file is durably persisted.
  sync

  # Append some data to our file, to increase its size.
  $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \
      $SCRATCH_MNT/foo | _filter_xfs_io

  # Fsync the file, so from this point on if a crash/power failure happens, our
  # new data is guaranteed to be there next time the fs is mounted.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

  # Now shrink our file to 5000 bytes.
  $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo

  # Now do an expanding truncate to a size larger than what we had when we last
  # fsync'ed our file. This is just to verify that after power failure and
  # replaying the fsync log, our file matches what it was when we last fsync'ed
  # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of
  # data had a value of 0xcc.
  $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo

  # Add one hard link to our file. This made btrfs drop all of our file's
  # metadata from the fsync log, including the metadata relative to the
  # extent we just wrote and fsync'ed. This change was made only to the fsync
  # log in memory, so adding the hard link alone doesn't change the persisted
  # fsync log. This happened because the previous truncates set the runtime
  # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure.
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link

  # Now make sure the in memory fsync log is durably persisted.
  # Creating and fsync'ing another file will do it.
  # After this our persisted fsync log will no longer have metadata for our file
  # foo that points to the extent we wrote and fsync'ed before.
  touch $SCRATCH_MNT/bar
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar

  # As expected, before the crash/power failure, we should be able to see a file
  # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all
  # the remaining bytes with value 0x00.
  echo "File content before:"
  od -t x1 $SCRATCH_MNT/foo

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # After mounting the fs again, the fsync log was replayed.
  # The expected result is to see a file with a size of 12Kb, with its first 8Kb
  # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc.
  # The btrfs bug used to leave the file as it used te be as of the last
  # transaction commit - that is, with a size of 8Kb with all bytes having a
  # value of 0xaa.
  echo "File content after:"
  od -t x1 $SCRATCH_MNT/foo

The test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:22:49 -08:00
Filipe Manana 1a4bcf470c Btrfs: fix fsync data loss after adding hard link to inode
We have a scenario where after the fsync log replay we can lose file data
that had been previously fsync'ed if we added an hard link for our inode
and after that we sync'ed the fsync log (for example by fsync'ing some
other file or directory).

This is because when adding an hard link we updated the inode item in the
log tree with an i_size value of 0. At that point the new inode item was
in memory only and a subsequent fsync log replay would not make us lose
the file data. However if after adding the hard link we sync the log tree
to disk, by fsync'ing some other file or directory for example, we ended
up losing the file data after log replay, because the inode item in the
persisted log tree had an an i_size of zero.

This is easy to reproduce, and the following excerpt from my test for
xfstests shows this:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create one file with data and fsync it.
  # This made the btrfs fsync log persist the data and the inode metadata with
  # a correct inode->i_size (4096 bytes).
  $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \
       $SCRATCH_MNT/foo | _filter_xfs_io

  # Now add one hard link to our file. This made the btrfs code update the fsync
  # log, in memory only, with an inode metadata having a size of 0.
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link

  # Now force persistence of the fsync log to disk, for example, by fsyncing some
  # other file.
  touch $SCRATCH_MNT/bar
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar

  # Before a power loss or crash, we could read the 4Kb of data from our file as
  # expected.
  echo "File content before:"
  od -t x1 $SCRATCH_MNT/foo

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # After the fsync log replay, because the fsync log had a value of 0 for our
  # inode's i_size, we couldn't read anymore the 4Kb of data that we previously
  # wrote and fsync'ed. The size of the file became 0 after the fsync log replay.
  echo "File content after:"
  od -t x1 $SCRATCH_MNT/foo

Another alternative test, that doesn't need to fsync an inode in the same
transaction it was created, is:

  _scratch_mkfs >> $seqres.full 2>&1
  _init_flakey
  _mount_flakey

  # Create our test file with some data.
  $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \
       $SCRATCH_MNT/foo | _filter_xfs_io

  # Make sure the file is durably persisted.
  sync

  # Append some data to our file, to increase its size.
  $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \
       $SCRATCH_MNT/foo | _filter_xfs_io

  # Fsync the file, so from this point on if a crash/power failure happens, our
  # new data is guaranteed to be there next time the fs is mounted.
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

  # Add one hard link to our file. This made btrfs write into the in memory fsync
  # log a special inode with generation 0 and an i_size of 0 too. Note that this
  # didn't update the inode in the fsync log on disk.
  ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link

  # Now make sure the in memory fsync log is durably persisted.
  # Creating and fsync'ing another file will do it.
  touch $SCRATCH_MNT/bar
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar

  # As expected, before the crash/power failure, we should be able to read the
  # 12Kb of file data.
  echo "File content before:"
  od -t x1 $SCRATCH_MNT/foo

  # Simulate a crash/power loss.
  _load_flakey_table $FLAKEY_DROP_WRITES
  _unmount_flakey

  _load_flakey_table $FLAKEY_ALLOW_WRITES
  _mount_flakey

  # After mounting the fs again, the fsync log was replayed.
  # The btrfs fsync log replay code didn't update the i_size of the persisted
  # inode because the inode item in the log had a special generation with a
  # value of 0 (and it couldn't know the correct i_size, since that inode item
  # had a 0 i_size too). This made the last 4Kb of file data inaccessible and
  # effectively lost.
  echo "File content after:"
  od -t x1 $SCRATCH_MNT/foo

This isn't a new issue/regression. This problem has been around since the
log tree code was added in 2008:

  Btrfs: Add a write ahead tree log to optimize synchronous operations
  (commit e02119d5a7)

Test cases for xfstests follow soon.

CC: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:22:49 -08:00
Forrest Liu 3d84be7991 Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group
Removing large amount of block group in a transaction may encounters
BUG_ON() in btrfs_orphan_add(). That is because btrfs_orphan_reserve_metadata()
will grab metadata reservation from transaction handle, and
btrfs_delete_unused_bgs() didn't reserve metadata for trnasaction handle when
delete unused block group.

The problem can be reproduce by following script

    mntpath=/btrfs
    loopdev=/dev/loop0
    filepath=/home/forrest/image

    umount $mntpath
    losetup -d $loopdev
    truncate --size 1000g $filepath
    losetup $loopdev $filepath
    mkfs.btrfs -f $loopdev
    mount $loopdev $mntpath

    for j in `seq 1 1 1000`; do
        fallocate -l 1g $mntpath/$j
    done
    # wait cleaner thread remove unused block group
    sleep 300

The call trace that results from the BUG_ON() is:

[  613.093084] ------------[ cut here ]------------
[  613.097928] kernel BUG at fs/btrfs/inode.c:3142!
[  613.105855] invalid opcode: 0000 [#1] SMP
[  613.112702] Modules linked in: coretemp(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) snd_ens1371(E) snd_ac97_codec(E) aes_x86_64(E) lrw(E) gf128mul(E) glue_helper(E) ppdev(E) ac97_bus(E) ablk_helper(E) gameport(E) cryptd(E) snd_rawmidi(E) snd_seq_device(E) snd_pcm(E) vmw_balloon(E) snd_timer(E) snd(E) soundcore(E) serio_raw(E) vmwgfx(E) ttm(E) drm_kms_helper(E) drm(E) vmw_vmci(E) parport_pc(E) shpchp(E) i2c_piix4(E) mac_hid(E) lp(E) parport(E) btrfs(E) xor(E) raid6_pq(E) hid_generic(E) usbhid(E) hid(E) psmouse(E) ahci(E) libahci(E) e1000(E) mptspi(E) mptscsih(E) mptbase(E) floppy(E) vmw_pvscsi(E) vmxnet3(E)
[  613.144196] CPU: 0 PID: 1480 Comm: btrfs-cleaner Tainted: G            E  3.19.0-rc7-custom #2
[  613.148501] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[  613.152694] task: ffff880035cdb1a0 ti: ffff880039cf4000 task.ti: ffff880039cf4000
[  613.154969] RIP: 0010:[<ffffffffa01441c2>]  [<ffffffffa01441c2>] btrfs_orphan_add+0x1d2/0x1e0 [btrfs]
[  613.157780] RSP: 0018:ffff880039cf7c48  EFLAGS: 00010286
[  613.159560] RAX: 00000000ffffffe4 RBX: ffff88003bd981a0 RCX: ffff88003c9e4000
[  613.161904] RDX: 0000000000002244 RSI: 0000000000040000 RDI: ffff88003c9e4138
[  613.164264] RBP: ffff880039cf7c88 R08: 000060ffc0000850 R09: 0000000000000000
[  613.166507] R10: ffff88003bc4b7a0 R11: ffffea0000eb6740 R12: ffff88003c9c0000
[  613.168681] R13: ffff88003c102160 R14: ffff88003c9c0458 R15: 0000000000000001
[  613.170932] FS:  0000000000000000(0000) GS:ffff88003f600000(0000) knlGS:0000000000000000
[  613.173316] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  613.175227] CR2: 00007f6343537000 CR3: 0000000036329000 CR4: 00000000000407f0
[  613.177554] Stack:
[  613.178712]  ffff880039cf7c88 ffffffffa0182a54 ffff88003c9e4b04 ffff88003c9c7800
[  613.181297]  ffff88003bc4b7a0 ffff88003bd981a0 ffff88003c8db200 ffff88003c2fcc60
[  613.183782]  ffff880039cf7d18 ffffffffa012da97 ffff88003bc4b7a4 ffff88003bc4b7a0
[  613.186171] Call Trace:
[  613.187493]  [<ffffffffa0182a54>] ? lookup_free_space_inode+0x44/0x100 [btrfs]
[  613.189801]  [<ffffffffa012da97>] btrfs_remove_block_group+0x137/0x740 [btrfs]
[  613.192126]  [<ffffffffa0166912>] btrfs_remove_chunk+0x672/0x780 [btrfs]
[  613.194267]  [<ffffffffa012e2ff>] btrfs_delete_unused_bgs+0x25f/0x280 [btrfs]
[  613.196567]  [<ffffffffa0135e4c>] cleaner_kthread+0x12c/0x190 [btrfs]
[  613.198687]  [<ffffffffa0135d20>] ? check_leaf+0x350/0x350 [btrfs]
[  613.200758]  [<ffffffff8108f232>] kthread+0xd2/0xf0
[  613.202616]  [<ffffffff8108f160>] ? kthread_create_on_node+0x180/0x180
[  613.204738]  [<ffffffff8175dabc>] ret_from_fork+0x7c/0xb0
[  613.206652]  [<ffffffff8108f160>] ? kthread_create_on_node+0x180/0x180
[  613.208741] Code: ff ff 0f 1f 80 00 00 00 00 89 45 c8 3e 80 63 80 fd 48 89 df e8 d0 23 fe ff 8b 45 c8 e9 14 ff ff ff b8 f4 ff ff ff e9 12 ff ff ff <0f> 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48
[  613.216562] RIP  [<ffffffffa01441c2>] btrfs_orphan_add+0x1d2/0x1e0 [btrfs]
[  613.218828]  RSP <ffff880039cf7c48>
[  613.220382] ---[ end trace 71073106deb8a457 ]---

This patch replace btrfs_join_transaction() with btrfs_start_transaction() in
btrfs_delete_unused_bgs() to revent BUG_ON() in btrfs_orphan_add()

Signed-off-by: Forrest Liu <forrestl@synology.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:22:49 -08:00
Josef Bacik dcab6a3b2a Btrfs: account for large extents with enospc
On our gluster boxes we stream large tar balls of backups onto our fses.  With
160gb of ram this means we get really large contiguous ranges of dirty data, but
the way our ENOSPC stuff works is that as long as it's contiguous we only hold
metadata reservation for one extent.  The problem is we limit our extents to
128mb, so we'll end up with at least 800 extents so our enospc accounting is
quite a bit lower than what we need.  To keep track of this make sure we
increase outstanding_extents for every multiple of the max extent size so we can
be sure to have enough reserved metadata space.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:22:48 -08:00
Josef Bacik 3266789f9d Btrfs: don't set and clear delalloc for O_DIRECT writes
We do this to get the space accounting, but this is just needless churn on the
io_tree, so just drop setting/clearing delalloc and just drop the reserved data
space when we have a successfull allocation.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
Josef Bacik 3e05bde8c3 Btrfs: only adjust outstanding_extents when we do a short write
We have this weird dance where we always inc outstanding_extents when we do a
O_DIRECT write, even if we allocate the entire range.  To get around this we
also drop the metadata space if we successfully write.  This is an unnecessary
dance, we only need to jack up outstanding_extents if we don't satisfy the
entire range request in get_blocks_direct, otherwise we are good using our
original reservation.  So drop the unconditional inc and the drop of the
metadata space that we have for the unconditional inc.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
Zhao Lei 13212b54d1 btrfs: Fix out-of-space bug
Btrfs will report NO_SPACE when we create and remove files for several times,
and we can't write to filesystem until mount it again.

Steps to reproduce:
 1: Create a single-dev btrfs fs with default option
 2: Write a file into it to take up most fs space
 3: Delete above file
 4: Wait about 100s to let chunk removed
 5: goto 2

Script is like following:
 #!/bin/bash

 # Recommend 1.2G space, too large disk will make test slow
 DEV="/dev/sda16"
 MNT="/mnt/tmp"

 dev_size="$(lsblk -bn -o SIZE "$DEV")" || exit 2
 file_size_m=$((dev_size * 75 / 100 / 1024 / 1024))

 echo "Loop write ${file_size_m}M file on $((dev_size / 1024 / 1024))M dev"

 for ((i = 0; i < 10; i++)); do umount "$MNT" 2>/dev/null; done
 echo "mkfs $DEV"
 mkfs.btrfs -f "$DEV" >/dev/null || exit 2
 echo "mount $DEV $MNT"
 mount "$DEV" "$MNT" || exit 2

 for ((loop_i = 0; loop_i < 20; loop_i++)); do
     echo
     echo "loop $loop_i"

     echo "dd file..."
     cmd=(dd if=/dev/zero of="$MNT"/file0 bs=1M count="$file_size_m")
     "${cmd[@]}" 2>/dev/null || {
         # NO_SPACE error triggered
         echo "dd failed: ${cmd[*]}"
         exit 1
     }

     echo "rm file..."
     rm -f "$MNT"/file0 || exit 2

     for ((i = 0; i < 10; i++)); do
         df "$MNT" | tail -1
         sleep 10
     done
 done

Reason:
 It is triggered by commit: 47ab2a6c68
 which is used to remove empty block groups automatically, but the
 reason is not in that patch. Code before works well because btrfs
 don't need to create and delete chunks so many times with high
 complexity.
 Above bug is caused by many reason, any of them can trigger it.

Reason1:
 When we remove some continuous chunks but leave other chunks after,
 these disk space should be used by chunk-recreating, but in current
 code, only first create will successed.
 Fixed by Forrest Liu <forrestl@synology.com> in:
 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole

Reason2:
 contains_pending_extent() return wrong value in calculation.
 Fixed by Forrest Liu <forrestl@synology.com> in:
 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole

Reason3:
 btrfs_check_data_free_space() try to commit transaction and retry
 allocating chunk when the first allocating failed, but space_info->full
 is set in first allocating, and prevent second allocating in retry.
 Fixed in this patch by clear space_info->full in commit transaction.

 Tested for severial times by above script.

Changelog v3->v4:
 use light weight int instead of atomic_t to record have_remove_bgs in
 transaction, suggested by:
 Josef Bacik <jbacik@fb.com>

Changelog v2->v3:
 v2 fixed the bug by adding more commit-transaction, but we
 only need to reclaim space when we are really have no space for
 new chunk, noticed by:
 Filipe David Manana <fdmanana@gmail.com>

 Actually, our code already have this type of commit-and-retry,
 we only need to make it working with removed-bgs.
 v3 fixed the bug with above way.

Changelog v1->v2:
 v1 will introduce a new bug when delete and create chunk in same disk
 space in same transaction, noticed by:
 Filipe David Manana <fdmanana@gmail.com>
 V2 fix this bug by commit transaction after remove block grops.

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Suggested-by: Filipe David Manana <fdmanana@gmail.com>
Suggested-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
Filipe Manana f55985f4dd Btrfs: scrub, fix sleep in atomic context
My previous patch "Btrfs: fix scrub race leading to use-after-free"
introduced the possibility to sleep in an atomic context, which happens
when the scrub_lock mutex is held at the time scrub_pending_bio_dec()
is called - this function can be called under an atomic context.
Chris ran into this in a debug kernel which gave the following trace:

[ 1928.950319] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:621
[ 1928.967334] in_atomic(): 1, irqs_disabled(): 0, pid: 149670, name: fsstress
[ 1928.981324] INFO: lockdep is turned off.
[ 1928.989244] CPU: 24 PID: 149670 Comm: fsstress Tainted: G        W     3.19.0-rc7-mason+ #41
[ 1929.006418] Hardware name: ZTSYSTEMS Echo Ridge T4  /A9DRPF-10D, BIOS 1.07 05/10/2012
[ 1929.022207]  ffffffff81a22cf8 ffff881076e03b78 ffffffff816b8dd9 ffff881076e03b78
[ 1929.037267]  ffff880d8e828710 ffff881076e03ba8 ffffffff810856c4 ffff881076e03bc8
[ 1929.052315]  0000000000000000 000000000000026d ffffffff81a22cf8 ffff881076e03bd8
[ 1929.067381] Call Trace:
[ 1929.072344]  <IRQ>  [<ffffffff816b8dd9>] dump_stack+0x4f/0x6e
[ 1929.083968]  [<ffffffff810856c4>] ___might_sleep+0x174/0x230
[ 1929.095352]  [<ffffffff810857d2>] __might_sleep+0x52/0x90
[ 1929.106223]  [<ffffffff816bb68f>] mutex_lock_nested+0x2f/0x3b0
[ 1929.117951]  [<ffffffff810ab37d>] ? trace_hardirqs_on+0xd/0x10
[ 1929.129708]  [<ffffffffa05dc838>] scrub_pending_bio_dec+0x38/0x70 [btrfs]
[ 1929.143370]  [<ffffffffa05dd0e0>] scrub_parity_bio_endio+0x50/0x70 [btrfs]
[ 1929.157191]  [<ffffffff812fa603>] bio_endio+0x53/0xa0
[ 1929.167382]  [<ffffffffa05f96bc>] rbio_orig_end_io+0x7c/0xa0 [btrfs]
[ 1929.180161]  [<ffffffffa05f97ba>] raid_write_parity_end_io+0x5a/0x80 [btrfs]
[ 1929.194318]  [<ffffffff812fa603>] bio_endio+0x53/0xa0
[ 1929.204496]  [<ffffffff8130401b>] blk_update_request+0x1eb/0x450
[ 1929.216569]  [<ffffffff81096e58>] ? trigger_load_balance+0x78/0x500
[ 1929.229176]  [<ffffffff8144c74d>] scsi_end_request+0x3d/0x1f0
[ 1929.240740]  [<ffffffff8144ccac>] scsi_io_completion+0xac/0x5b0
[ 1929.252654]  [<ffffffff81441c50>] scsi_finish_command+0xf0/0x150
[ 1929.264725]  [<ffffffff8144d317>] scsi_softirq_done+0x147/0x170
[ 1929.276635]  [<ffffffff8130ace6>] blk_done_softirq+0x86/0xa0
[ 1929.288014]  [<ffffffff8105d92e>] __do_softirq+0xde/0x600
[ 1929.298885]  [<ffffffff8105df6d>] irq_exit+0xbd/0xd0
(...)

Fix this by using a reference count on the scrub context structure
instead of locking the scrub_lock mutex.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
Filipe Manana 575849ecf5 Btrfs: fix scheduler warning when syncing log
We try to lock a mutex while the current task state is not TASK_RUNNING,
which results in the following warning when CONFIG_DEBUG_LOCK_ALLOC=y:

[30736.772501] ------------[ cut here ]------------
[30736.774545] WARNING: CPU: 9 PID: 19972 at kernel/sched/core.c:7300 __might_sleep+0x8b/0xa8()
[30736.783453] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff8107499b>] prepare_to_wait+0x43/0x89
[30736.786261] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc psmouse parport pcspkr microcode serio_raw evdev processor thermal_sys i2c_piix4 i2c_core button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring e1000 virtio scsi_mod
[30736.794323] CPU: 9 PID: 19972 Comm: fsstress Not tainted 3.19.0-rc7-btrfs-next-5+ #1
[30736.795821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[30736.798788]  0000000000000009 ffff88042743fbd8 ffffffff814248ed ffff88043d32f2d8
[30736.800504]  ffff88042743fc28 ffff88042743fc18 ffffffff81045338 0000000000000001
[30736.802131]  ffffffff81064514 ffffffff817c52d1 000000000000026d 0000000000000000
[30736.803676] Call Trace:
[30736.804256]  [<ffffffff814248ed>] dump_stack+0x4c/0x65
[30736.805245]  [<ffffffff81045338>] warn_slowpath_common+0xa1/0xbb
[30736.806360]  [<ffffffff81064514>] ? __might_sleep+0x8b/0xa8
[30736.807391]  [<ffffffff81045398>] warn_slowpath_fmt+0x46/0x48
[30736.808511]  [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89
[30736.809620]  [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89
[30736.810691]  [<ffffffff81064514>] __might_sleep+0x8b/0xa8
[30736.811703]  [<ffffffff81426eaf>] mutex_lock_nested+0x2f/0x3a0
[30736.812889]  [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab
[30736.814138]  [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf
[30736.819878]  [<ffffffffa038cfff>] wait_for_writer.isra.12+0x91/0xaa [btrfs]
[30736.821260]  [<ffffffff810748bd>] ? signal_pending_state+0x31/0x31
[30736.822410]  [<ffffffffa0391f0a>] btrfs_sync_log+0x160/0x947 [btrfs]
[30736.823574]  [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab
[30736.824847]  [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf
[30736.825972]  [<ffffffffa036e555>] btrfs_sync_file+0x2b0/0x319 [btrfs]
[30736.827684]  [<ffffffff8117901a>] vfs_fsync_range+0x21/0x23
[30736.828932]  [<ffffffff81179038>] vfs_fsync+0x1c/0x1e
[30736.829917]  [<ffffffff8117928b>] do_fsync+0x34/0x4e
[30736.830862]  [<ffffffff811794b3>] SyS_fsync+0x10/0x14
[30736.831819]  [<ffffffff8142a512>] system_call_fastpath+0x12/0x17
[30736.832982] ---[ end trace c0b57df60d32ae5c ]---

Fix this my acquiring the mutex after calling finish_wait(), which sets the
task's state to TASK_RUNNING.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
Linus Torvalds 6bec003528 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block
Pull backing device changes from Jens Axboe:
 "This contains a cleanup of how the backing device is handled, in
  preparation for a rework of the life time rules.  In this part, the
  most important change is to split the unrelated nommu mmap flags from
  it, but also removing a backing_dev_info pointer from the
  address_space (and inode), and a cleanup of other various minor bits.

  Christoph did all the work here, I just fixed an oops with pages that
  have a swap backing.  Arnd fixed a missing export, and Oleg killed the
  lustre backing_dev_info from staging.  Last patch was from Al,
  unexporting parts that are now no longer needed outside"

* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
  Make super_blocks and sb_lock static
  mtd: export new mtd_mmap_capabilities
  fs: make inode_to_bdi() handle NULL inode
  staging/lustre/llite: get rid of backing_dev_info
  fs: remove default_backing_dev_info
  fs: don't reassign dirty inodes to default_backing_dev_info
  nfs: don't call bdi_unregister
  ceph: remove call to bdi_unregister
  fs: remove mapping->backing_dev_info
  fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
  nilfs2: set up s_bdi like the generic mount_bdev code
  block_dev: get bdev inode bdi directly from the block device
  block_dev: only write bdev inode on close
  fs: introduce f_op->mmap_capabilities for nommu mmap support
  fs: kill BDI_CAP_SWAP_BACKED
  fs: deduplicate noop_backing_dev_info
2015-02-12 13:50:21 -08:00
Konstantin Khebnikov 8d38633c3b page_writeback: put account_page_redirty() after set_page_dirty()
Helper account_page_redirty() fixes dirty pages counter for redirtied
pages.  This patch puts it after dirtying and prevents temporary
underflows of dirtied pages counters on zone/bdi and current->nr_dirtied.

Signed-off-by: Konstantin Khebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:04 -08:00
Kirill A. Shutemov d83a08db5b mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub
Nobody uses it anymore.

[akpm@linux-foundation.org: fix filemap_xip.c]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:30 -08:00
Linus Torvalds 23e8fe2e16 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle are:

   - Documentation updates.

   - Miscellaneous fixes.

   - Preemptible-RCU fixes, including fixing an old bug in the
     interaction of RCU priority boosting and CPU hotplug.

   - SRCU updates.

   - RCU CPU stall-warning updates.

   - RCU torture-test updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  rcu: Initialize tiny RCU stall-warning timeouts at boot
  rcu: Fix RCU CPU stall detection in tiny implementation
  rcu: Add GP-kthread-starvation checks to CPU stall warnings
  rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors
  rcu: Optionally run grace-period kthreads at real-time priority
  ksoftirqd: Use new cond_resched_rcu_qs() function
  ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
  rcutorture: Add more diagnostics in rcu_barrier() test failure case
  torture: Flag console.log file to prevent holdovers from earlier runs
  torture: Add "-enable-kvm -soundhw pcspk" to qemu command line
  rcutorture: Handle different mpstat versions
  rcutorture: Check from beginning to end of grace period
  rcu: Remove redundant rcu_batches_completed() declaration
  rcutorture: Drop rcu_torture_completed() and friends
  rcu: Provide rcu_batches_completed_sched() for TINY_RCU
  rcutorture: Use unsigned for Reader Batch computations
  rcutorture: Make build-output parsing correctly flag RCU's warnings
  rcu: Make _batches_completed() functions return unsigned long
  rcutorture: Issue warnings on close calls due to Reader Batch blows
  documentation: Fix smp typo in memory-barriers.txt
  ...
2015-02-09 14:28:42 -08:00
Linus Torvalds bdfeb5a104 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "Forrest Liu tracked down a missing blk_finish_plug in the btrfs
  logging code.  This isn't a new bug, and it's hard to hit.  But, it's
  safe enough for inclusion now, and in my for-linus branch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: add missing blk_finish_plug in btrfs_sync_log()
2015-02-07 11:04:48 -08:00
Forrest Liu 3da5ab5648 Btrfs: add missing blk_finish_plug in btrfs_sync_log()
Add missing blk_finish_plug in btrfs_sync_log()

Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-04 18:02:37 -08:00
Gui Hecheng b76808fc26 btrfs: cleanup init for list in free-space-cache
o removed an unecessary INIT_LIST_HEAD after LIST_HEAD

o merge a declare & INIT_LIST_HEAD pair into one LIST_HEAD

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:25:50 -08:00
Shaohua Li 2f0810880f btrfs: delete chunk allocation attemp when setting block group ro
Below test will fail currently:
      mkfs.ext4 -F /dev/sda
      btrfs-convert /dev/sda
      mount /dev/sda /mnt
      btrfs device add -f /dev/sdb /mnt
      btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt

The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:25:20 -08:00
Naohiro Aota 289454ad26 btrfs: clear bio reference after submit_one_bio()
After submit_one_bio(), `bio' can go away. However submit_extent_page()
leave `bio' referable if submit_one_bio() failed (e.g. -ENOMEM on OOM).
It will cause invalid paging request when submit_extent_page() is called
next time.

I reproduced ENOMEM case with the following script (need
CONFIG_FAIL_PAGE_ALLOC, and CONFIG_FAULT_INJECTION_DEBUG_FS).

  #!/bin/bash

  dmesgout=dmesg.txt
  start=100000
  end=300000
  step=1000

  # btrfs options
  device=/dev/vdb1
  directory=/mnt/btrfs

  # fault-injection options
  percent=100
  times=3

  mkdir -p $directory || exit 1
  mount -o compress $device $directory || exit 1

  rm -f $directory/file || exit 1
  dd if=/dev/zero of=$directory/file bs=1M count=512 || exit 1

  for interval in `seq $start $step $end`; do
          dmesg -C
          echo 1 > /proc/sys/vm/drop_caches
          sync
          export FAILCMD_TYPE=fail_page_alloc
          ./failcmd.sh -p $percent -t $times -i $interval \
                  --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \
                  -- \
                  cat $directory/file > /dev/null
          dmesg > ${dmesgout}
          if grep -q BUG: ${dmesgout}; then
                  cat ${dmesgout}
                  exit 1
          fi
  done

  umount $directory
  exit 0

Signed-off-by: Naohiro Aota <naota@elisp.net>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:51 -08:00
Filipe Manana de554a4fa6 Btrfs: fix scrub race leading to use-after-free
While running a scrub on a kernel with CONFIG_DEBUG_PAGEALLOC=y, I got
the following trace:

[68127.807663] BUG: unable to handle kernel paging request at ffff8803f8947a50
[68127.807663] IP: [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663] PGD 3003067 PUD 43e1f5067 PMD 43e030067 PTE 80000003f8947060
[68127.807663] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[68127.807663] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc processor parpo
[68127.807663] CPU: 2 PID: 3081 Comm: kworker/u8:5 Not tainted 3.18.0-rc6-btrfs-next-3+ #4
[68127.807663] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[68127.807663] Workqueue: btrfs-btrfs-scrub btrfs_scrub_helper [btrfs]
[68127.807663] task: ffff880101fc5250 ti: ffff8803f097c000 task.ti: ffff8803f097c000
[68127.807663] RIP: 0010:[<ffffffff8107da31>]  [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663] RSP: 0018:ffff8803f097fbb8  EFLAGS: 00010093
[68127.807663] RAX: 0000000028dd386c RBX: ffff8803f8947a50 RCX: 0000000028dd3854
[68127.807663] RDX: 0000000000000018 RSI: 0000000000000002 RDI: 0000000000000001
[68127.807663] RBP: ffff8803f097fbd8 R08: 0000000000000004 R09: 0000000000000001
[68127.807663] R10: ffff880102620980 R11: ffff8801f3e8c900 R12: 000000000001d390
[68127.807663] R13: 00000000cabd13c8 R14: ffff8803f8947800 R15: ffff88037c574f00
[68127.807663] FS:  0000000000000000(0000) GS:ffff88043dd00000(0000) knlGS:0000000000000000
[68127.807663] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[68127.807663] CR2: ffff8803f8947a50 CR3: 00000000b6481000 CR4: 00000000000006e0
[68127.807663] Stack:
[68127.807663]  ffffffff823942a8 ffff8803f8947a50 ffff8802a3416f80 0000000000000000
[68127.807663]  ffff8803f097fc18 ffffffff8141e7c0 ffffffff81072948 000000000034f314
[68127.807663]  ffff8803f097fc08 0000000000000292 ffff8803f097fc48 ffff8803f8947a50
[68127.807663] Call Trace:
[68127.807663]  [<ffffffff8141e7c0>] _raw_spin_lock_irqsave+0x4b/0x55
[68127.807663]  [<ffffffff81072948>] ? __wake_up+0x22/0x4b
[68127.807663]  [<ffffffff81072948>] __wake_up+0x22/0x4b
[68127.807663]  [<ffffffffa0392327>] scrub_pending_bio_dec+0x32/0x36 [btrfs]
[68127.807663]  [<ffffffffa0395e70>] scrub_bio_end_io_worker+0x5a3/0x5c9 [btrfs]
[68127.807663]  [<ffffffff810e0c7c>] ? time_hardirqs_off+0x15/0x28
[68127.807663]  [<ffffffff81078106>] ? trace_hardirqs_off_caller+0x4c/0xb9
[68127.807663]  [<ffffffffa0372a7c>] normal_work_helper+0xf1/0x238 [btrfs]
[68127.807663]  [<ffffffffa0372d3d>] btrfs_scrub_helper+0x12/0x14 [btrfs]
[68127.807663]  [<ffffffff810582d2>] process_one_work+0x1e4/0x3b6
[68127.807663]  [<ffffffff81078180>] ? trace_hardirqs_off+0xd/0xf
[68127.807663]  [<ffffffff81058dc9>] worker_thread+0x1fb/0x2a8
[68127.807663]  [<ffffffff81058bce>] ? rescuer_thread+0x219/0x219
[68127.807663]  [<ffffffff8105cd75>] kthread+0xdb/0xe3
[68127.807663]  [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67
[68127.807663]  [<ffffffff8141f1ec>] ret_from_fork+0x7c/0xb0
[68127.807663]  [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67
[68127.807663] Code: 39 c2 75 14 8d 8a 00 00 01 00 89 d0 f0 0f b1 0b 39 d0 0f 84 81 00 00 00 4c 69 2d 27 86 99 00 fa 00 00 00 45 31 e4 4d 39 ec 74 2b <8b> 13 89 d0 c1 e8 10 66 39 c2 75
[68127.807663] RIP  [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663]  RSP <ffff8803f097fbb8>
[68127.807663] CR2: ffff8803f8947a50
[68127.807663] ---[ end trace d7045aac00a66cd8 ]---

This is due to a race that can happen in a very tiny time window and is
illustrated by the following sequence diagram:

         CPU 1                                                     CPU 2

                                                                btrfs_scrub_dev()
scrub_bio_end_io_worker()
   scrub_pending_bio_dec()
       atomic_dec(&sctx->bios_in_flight)
                                                                   wait sctx->bios_in_flight == 0
                                                                   wait sctx->workers_pending == 0
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   (...)
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   scrub_free_ctx(sctx)
                                                                      kfree(sctx)
       wake_up(&sctx->list_wait)
          __wake_up()
              spin_lock_irqsave(&sctx->list_wait->lock, flags)

Another variation of this scenario that results in the same use-after-free
issue is:

         CPU 1                                                     CPU 2

                                                                btrfs_scrub_dev()
                                                                   wait sctx->bios_in_flight == 0
scrub_bio_end_io_worker()
   scrub_pending_bio_dec()
       __wake_up(&sctx->list_wait)
          spin_lock_irqsave(&sctx->list_wait->lock, flags)
          default_wake_function()
              wake up task at CPU 2
                                                                   wait sctx->workers_pending == 0
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   (...)
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   scrub_free_ctx(sctx)
                                                                      kfree(sctx)
          spin_unlock_irqrestore(&sctx->list_wait->lock, flags)

Fix this by holding the scrub lock while doing the wakeup.

This isn't a recent regression, the issue as been around since the scrub
feature was added (2011, commit a2de733c78).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:50 -08:00
Filipe Manana 001a648df4 Btrfs: add missing cleanup on sysfs init failure
If we failed during initialization of sysfs, we weren't unregistering the
top level btrfs sysfs entry nor the debugfs stuff.
Not unregistering the top level sysfs entry makes future attempts to reload
the btrfs module impossible and the following is reported in dmesg:

[ 2246.451296] WARNING: CPU: 3 PID: 10999 at fs/sysfs/dir.c:486 sysfs_warn_dup+0x91/0xb0()
[ 2246.451298] sysfs: cannot create duplicate filename '/fs/btrfs'
[ 2246.451298] Modules linked in: btrfs(+) raid6_pq xor bnep rfcomm bluetooth binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc parport_pc parport psmouse serio_raw pcspkr evbug i2c_piix4 e1000 floppy [last unloaded: btrfs]
[ 2246.451310] CPU: 3 PID: 10999 Comm: modprobe Tainted: G        W    3.13.0-fdm-btrfs-next-24+ #7
[ 2246.451311] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2246.451312]  0000000000000009 ffff8800d353fa08 ffffffff816f1da6 0000000000000410
[ 2246.451314]  ffff8800d353fa58 ffff8800d353fa48 ffffffff8104a32c ffff88020821a290
[ 2246.451316]  ffff88020821a290 ffff88020821a290 ffff8802148f0000 ffff8800d353fb80
[ 2246.451318] Call Trace:
[ 2246.451322]  [<ffffffff816f1da6>] dump_stack+0x4e/0x68
[ 2246.451324]  [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0
[ 2246.451325]  [<ffffffff8104a416>] warn_slowpath_fmt+0x46/0x50
[ 2246.451328]  [<ffffffff81367dc5>] ? strlcat+0x65/0x90
(....)

This fixes the following change:

    btrfs: add simple debugfs interface
    commit 1bae30982b

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:49 -08:00
Filipe Manana d4b450cd4b Btrfs: fix race between transaction commit and empty block group removal
Committing a transaction can race with automatic removal of empty block
groups (cleaner kthread), leading to a BUG_ON() in the transaction
commit code while running btrfs_finish_extent_commit(). The following
sequence diagram shows how it can happen:

           CPU 1                                       CPU 2

btrfs_commit_transaction()
  fs_info->running_transaction = NULL
  btrfs_finish_extent_commit()
    find_first_extent_bit()
      -> found range for block group X
         in fs_info->freed_extents[]

                                               btrfs_delete_unused_bgs()
                                                 -> found block group X

                                                 Removed block group X's range
                                                 from fs_info->freed_extents[]

                                                 btrfs_remove_chunk()
                                                    btrfs_remove_block_group(bg X)

    unpin_extent_range(bg X range)
       btrfs_lookup_block_group(bg X)
          -> returns NULL
            -> BUG_ON()

The trace that results from the BUG_ON() is:

[48665.187808] ------------[ cut here ]------------
[48665.188032] kernel BUG at fs/btrfs/extent-tree.c:5675!
[48665.188032] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[48665.188032] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc evdev microcode
[48665.197388] CPU: 2 PID: 31211 Comm: kworker/u32:16 Tainted: G        W      3.19.0-rc5-btrfs-next-4+ #1
[48665.197388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[48665.197388] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
[48665.197388] task: ffff880222011810 ti: ffff8801b56a4000 task.ti: ffff8801b56a4000
[48665.197388] RIP: 0010:[<ffffffffa0350d05>]  [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs]
[48665.197388] RSP: 0018:ffff8801b56a7b88  EFLAGS: 00010246
[48665.197388] RAX: 0000000000000000 RBX: ffff8802143a6000 RCX: ffff8802220120c8
[48665.197388] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8800a3c140b0
[48665.197388] RBP: ffff8801b56a7bd8 R08: 0000000000000003 R09: 0000000000000000
[48665.197388] R10: 0000000000000000 R11: 000000000000bbac R12: 0000000012e8e000
[48665.197388] R13: ffff8800a3c14000 R14: 0000000000000000 R15: 0000000000000000
[48665.197388] FS:  0000000000000000(0000) GS:ffff88023ec40000(0000) knlGS:0000000000000000
[48665.197388] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[48665.197388] CR2: 00007f065e42f270 CR3: 0000000206f70000 CR4: 00000000000006e0
[48665.197388] Stack:
[48665.197388]  ffff8801b56a7bd8 0000000012ea0000 01ff8800a3c14138 0000000012e9ffff
[48665.197388]  ffff880141df3dd8 ffff8802143a6000 ffff8800a3c14138 ffff880141df3df0
[48665.197388]  ffff880141df3dd8 0000000000000000 ffff8801b56a7c08 ffffffffa0354227
[48665.197388] Call Trace:
[48665.197388]  [<ffffffffa0354227>] btrfs_finish_extent_commit+0xb0/0xd9 [btrfs]
[48665.197388]  [<ffffffffa0366b4b>] btrfs_commit_transaction+0x791/0x92c [btrfs]
[48665.197388]  [<ffffffffa0352432>] flush_space+0x43d/0x452 [btrfs]
[48665.197388]  [<ffffffff814295c3>] ? _raw_spin_unlock+0x28/0x33
[48665.197388]  [<ffffffffa035255f>] btrfs_async_reclaim_metadata_space+0x118/0x164 [btrfs]
[48665.197388]  [<ffffffff81059917>] ? process_one_work+0x14b/0x3ab
[48665.197388]  [<ffffffff810599ac>] process_one_work+0x1e0/0x3ab
[48665.197388]  [<ffffffff81079fa9>] ? trace_hardirqs_off+0xd/0xf
[48665.197388]  [<ffffffff8105a55b>] worker_thread+0x210/0x2d0
[48665.197388]  [<ffffffff8105a34b>] ? rescuer_thread+0x2c3/0x2c3
[48665.197388]  [<ffffffff8105e5c0>] kthread+0xef/0xf7
[48665.197388]  [<ffffffff81429682>] ? _raw_spin_unlock_irq+0x2d/0x39
[48665.197388]  [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad
[48665.197388]  [<ffffffff81429dec>] ret_from_fork+0x7c/0xb0
[48665.197388]  [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad
[48665.197388] Code: 85 f6 74 14 49 8b 06 49 03 46 09 49 39 c4 72 1d 4c 89 f7 e8 83 ec ff ff 4c 89 e6 4c 89 ef e8 1e f1 ff ff 48 85 c0 49 89 c6 75 02 <0f> 0b 49 8b 1e 49 03 5e 09 48 8b
[48665.197388] RIP  [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs]
[48665.197388]  RSP <ffff8801b56a7b88>
[48665.272246] ---[ end trace b9c6ab9957521376 ]---

Fix this by ensuring that unpining the block group's range in
btrfs_finish_extent_commit() is done in a synchronized fashion
with removing the block group's range from freed_extents[]
in btrfs_delete_unused_bgs()

This race got introduced with the change:

    Btrfs: remove empty block groups automatically
    commit 47ab2a6c68

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:48 -08:00
David Sterba e3540eab29 btrfs: add more checks to btrfs_read_sys_array
Verify that the sys_array has enough bytes to read the next item.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:39 -08:00
David Sterba 1ffb22cf8c btrfs: cleanup, rename a few variables in btrfs_read_sys_array
There's a pointer to buffer, integer offset and offset passed as
pointer, try to find matching names for them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:28 -08:00
David Sterba ce7fca5f57 btrfs: add checks for sys_chunk_array sizes
Verify that possible minimum and maximum size is set, validity of
contents is checked in btrfs_read_sys_array.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:23:43 -08:00
David Sterba 75d6ad382b btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize
I received a few crafted images from Jiri, all got through the recently
added superblock checks. The lower bounds checks for num_devices and
sector/node -sizes were missing and caused a crash during mount.

Tools for symbolic code execution were used to prepare the images
contents.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:20:39 -08:00
chandan r 9cc97d6462 Btrfs: Add code to support file creation time
This patch adds a new member to the 'struct btrfs_inode' structure to hold
the file creation time.

Signed-off-by: chandan <chandanrmail@gmail.com>
[refreshed, removed btrfs_inode_otime]
Signed-off-by: David Sterba <dsterba@suse.cz>

Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 18:39:16 -08:00
David Sterba a937b9791e btrfs: kill btrfs_inode_*time helpers
They just opencode taking address of the timespec member.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 18:39:07 -08:00
Linus Torvalds bc208e0ee0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "We have one more fix for btrfs in my for-linus branch - this was a bug
  in the new raid5/6 scrubbing support"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix raid56 scrub failed in xfstests btrfs/072
2015-01-30 14:25:52 -08:00
Gui Hecheng 063c54dccd btrfs: fix raid56 scrub failed in xfstests btrfs/072
The xfstests btrfs/072 reports uncorrectable read errors in dmesg,
because scrub forgets to use commit_root for parity scrub routine
and scrub attempts to scrub those extents items whose contents are
not fully on disk.

To fix it, we just add the @search_commit_root flag back.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-27 15:26:16 -08:00
Linus Torvalds c4e00f1d31 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "We have a few fixes in my for-linus branch.

  Qu Wenruo's batch fix a regression between some our merge window pull
  and the inode_cache feature.  The rest are smaller bugs"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: Don't call btrfs_start_transaction() on frozen fs to avoid deadlock.
  btrfs: Fix the bug that fs_info->pending_changes is never cleared.
  btrfs: fix state->private cast on 32 bit machines
  Btrfs: fix race deleting block group from space_info->ro_bgs list
  Btrfs: fix incorrect freeing in scrub_stripe
  btrfs: sync ioctl, handle errors after transaction start
2015-01-24 14:31:27 +12:00
chandan 95449a1626 Btrfs: insert_new_root: Fix lock type of the extent buffer.
btrfs_alloc_tree_block() returns an extent buffer on which a blocked lock has
been taken. Hence assign the appropriate value to path->locks[level].

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22 05:42:23 -08:00
Anand Jain 78f55e5e1f Btrfs: fix unused members in struct btrfs_root
There isn't any real use of following members of struct btrfs_root
so delete them.

struct kobject root_kobj;
struct completion kobj_unregister;

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:22:37 -08:00
Yang Dongsheng 0ee13fe28c btrfs: qgroup: move WARN_ON() to the correct location.
In function qgroup_excl_accounting(), we need to WARN when
qg->excl is less than what we want to free, same to child
and parents. But currently, for parent qgroup, the WARN_ON()
is located after freeing qg->excl. It will WARN out even we
free it normally.

This patch move this WARN_ON() before freeing qg->excl.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:22:37 -08:00
Liu Bo 26455d3318 Btrfs: cleanup unused run_most
"run_most" is not used anymore.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:22:16 -08:00
Zhao Lei 570193454a Rename all ref_count to refs in struct
refs is better than ref_count to record a struct's ref count.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Suggested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:50 -08:00
Zhao Lei ffe2d2034b Btrfs: Introduce BTRFS_BLOCK_GROUP_RAID56_MASK to check raid56 simply
So we can check raid56 with:
 (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
instead of long:
 (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei 10f1190016 Btrfs: Include map_type in raid_bio
Corrent code use many kinds of "clever" way to determine operation
target's raid type, as:
  raid_map != NULL
  or
  raid_map[MAX_NR] == RAID[56]_Q_STRIPE

To make code easy to maintenance, this patch put raid type into
bbio, and we can always get raid type from bbio with a "stupid"
way.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei be50a8ddaa Btrfs: Simplify scrub_setup_recheck_block()'s argument
scrub_setup_recheck_block() have many arguments but most of them
can be get from one of them, we can remove them to make code clean.
Some other cleanup for that function also included in this patch.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei b968fed1c3 Btrfs: Combine per-page recover in dev-replace and scrub
The code are similar, combine them to make code clean and easy to maintenance.
Some lost condition are also completed with benefit of this combination.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei 8d6738c1bd Btrfs: Separate finding-right-mirror and writing-to-target's process in scrub_handle_errored_block()
In corrent code, code of finding-right-mirror and writing-to-target
are mixed in logic, if we find a right mirror but failed in writing
to target, it will treat as "hadn't found right block", and fill the
target with sblock_bad.

Actually, "failed in writing to target" does not mean "source
block is wrong", this patch separate above two condition in logic,
and do some cleanup to make code clean.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei dc5f7a3bd8 Btrfs: Break loop when reach BTRFS_MAX_MIRRORS in scrub_setup_recheck_block()
Use break instead of useless loop should be more suitable in this
case.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei 7653947fe6 Btrfs: btrfs_rm_dev_replace_blocked(): Use wait_event()
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei 09dd7a01c3 Btrfs: Cleanup btrfs_bio_counter_inc_blocked()
1: Remove no-need DEFINE_WAIT(wait)
2: Add likely() for BTRFS_FS_STATE_DEV_REPLACING condition
3: Use while loop instead of goto

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei 114ab50d82 Btrfs: Remove noneed force_write in scrub_write_block_to_dev_replace
It is always 1 in this place, because !1 case was already jumped
out in previous code.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei b25c94c580 Btrfs: Fix a jump typo of nodatasum_case to avoid wrong WARN_ON()
if (sctx->is_dev_replace && !is_metadata && !have_csum) {
    ...
    goto nodatasum_case;
}
...
nodatasum_case:
    WARN_ON(sctx->is_dev_replace);

In above code, nodatasum_case marker should be moved after
WARN_ON().

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei 6e9606d2a2 Btrfs: add ref_count and free function for btrfs_bio
1: ref_count is simple than current RBIO_HOLD_BBIO_MAP_BIT flag
   to keep btrfs_bio's memory in raid56 recovery implement.
2: free function for bbio will make code clean and flexible, plus
   forced data type checking in compile.

Changelog v1->v2:
 Rename following by David Sterba's suggestion:
 put_btrfs_bio() -> btrfs_put_bio()
 get_btrfs_bio() -> btrfs_get_bio()
 bbio->ref_count -> bbio->refs

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei 8e5cfb55d3 Btrfs: Make raid_map array be inlined in btrfs_bio structure
It can make code more simple and clear, we need not care about
free bbio and raid_map together.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:47 -08:00
Zhao Lei cc7539edea Btrfs: sort raid_map before adding tgtdev stripes
It can avoid complex calculation of real stripes in sort,
moreover, we can clean up code of sorting tgtdev_map because it
will be in order initially.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:47 -08:00
Zhao Lei e34c330d63 Btrfs: fix a out-of-bound access of raid_map
We add the number of stripes on target devices into bbio->num_stripes
if we are under device replacement, and we just sort the raid_map of
those stripes that not on the target devices, so if when we need
real raid_map, we need skip the stripes on the target devices.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:47 -08:00
Filipe Manana df8d116ffa Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs
If we have an inode with a large number of hard links, some of which may
be extrefs, turn a regular ref into an extref, fsync the inode and then
replay the fsync log (after a crash/reboot), we can endup with an fsync
log that makes the replay code always fail with -EOVERFLOW when processing
the inode's references.

This is easy to reproduce with the test case I made for xfstests. Its steps
are the following:

   _scratch_mkfs "-O extref" >> $seqres.full 2>&1
   _init_flakey
   _mount_flakey

   # Create a test file with 3001 hard links. This number is large enough to
   # make btrfs start using extrefs at some point even if the fs has the maximum
   # possible leaf/node size (64Kb).
   echo "hello world" > $SCRATCH_MNT/foo
   for i in `seq 1 3000`; do
       ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i`
   done

   # Make sure all metadata and data are durably persisted.
   sync

   # Now remove one link, add a new one with a new name, add another new one with
   # the same name as the one we just removed and fsync the inode.
   rm -f $SCRATCH_MNT/foo_link_0001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001
   rm -f $SCRATCH_MNT/foo_link_0002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003
   $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

   # Simulate a crash/power loss. This makes sure the next mount
   # will see an fsync log and will replay that log.

   _load_flakey_table $FLAKEY_DROP_WRITES
   _unmount_flakey

   _load_flakey_table $FLAKEY_ALLOW_WRITES
   _mount_flakey

   # Check that the number of hard links is correct, we are able to remove all
   # the hard links and read the file's data. This is just to verify we don't
   # get stale file handle errors (due to dangling directory index entries that
   # point to inodes that no longer exist).
   echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)"
   [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing"
   for ((i = 1; i <= 3003; i++)); do
       name=foo_link_`printf "%04d" $i`
       if [ $i -eq 2 ]; then
           [ -f $SCRATCH_MNT/$name ] && echo "Link $name found"
       else
           [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing"
       fi
   done
   rm -f $SCRATCH_MNT/foo_link_*
   cat $SCRATCH_MNT/foo
   rm -f $SCRATCH_MNT/foo

   status=0
   exit

The fix is simply to correct the overflow condition when overwriting a
reference item because it was wrong, trying to increase the item in the
fs/subvol tree by an impossible amount. Also ensure that we don't insert
one normal ref and one ext ref for the same dentry - this happened because
processing a dir index entry from the parent in the log happened when
the normal ref item was full, which made the logic insert an extref and
later when the normal ref had enough room, it would be inserted again
when processing the ref item from the child inode in the log.

This issue has been present since the introduction of the extrefs feature
(2012).

A test case for xfstests follows soon. This test only passes if the previous
patch titled "Btrfs: fix fsync when extend references are added to an inode"
is applied too.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:05 -08:00
Filipe Manana 2c2c452b0c Btrfs: fix fsync when extend references are added to an inode
If we added an extended reference to an inode and fsync'ed it, the log
replay code would make our inode have an incorrect link count, which
was lower then the expected/correct count.
This resulted in stale directory index entries after deleting some of
the hard links, and any access to the dangling directory entries resulted
in -ESTALE errors because the entries pointed to inode items that don't
exist anymore.

This is easy to reproduce with the test case I made for xfstests, and
the bulk of that test is:

    _scratch_mkfs "-O extref" >> $seqres.full 2>&1
    _init_flakey
    _mount_flakey

    # Create a test file with 3001 hard links. This number is large enough to
    # make btrfs start using extrefs at some point even if the fs has the maximum
    # possible leaf/node size (64Kb).
    echo "hello world" > $SCRATCH_MNT/foo
    for i in `seq 1 3000`; do
        ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i`
    done

    # Make sure all metadata and data are durably persisted.
    sync

    # Add one more link to the inode that ends up being a btrfs extref and fsync
    # the inode.
    ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001
    $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

    # Simulate a crash/power loss. This makes sure the next mount
    # will see an fsync log and will replay that log.

    _load_flakey_table $FLAKEY_DROP_WRITES
    _unmount_flakey

    _load_flakey_table $FLAKEY_ALLOW_WRITES
    _mount_flakey

    # Now after the fsync log replay btrfs left our inode with a wrong link count N,
    # which was smaller than the correct link count M (N < M).
    # So after removing N hard links, the remaining M - N directory entries were
    # still visible to user space but it was impossible to do anything with them
    # because they pointed to an inode that didn't exist anymore. This resulted in
    # stale file handle errors (-ESTALE) when accessing those dentries for example.
    #
    # So remove all hard links except the first one and then attempt to read the
    # file, to verify we don't get an -ESTALE error when accessing the inodel
    #
    # The btrfs fsck tool also detected the incorrect inode link count and it
    # reported an error message like the following:
    #
    # root 5 inode 257 errors 2001, no inode item, link count wrong
    #   unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref
    #
    # The fstests framework automatically calls fsck after a test is run, so we
    # don't need to call fsck explicitly here.

    rm -f $SCRATCH_MNT/foo_link_*
    cat $SCRATCH_MNT/foo

    status=0
    exit

So make sure an fsync always flushes the delayed inode item, so that the
fsync log contains it (needed in order to trigger the link count fixup
code) and fix the extref counting function, which always return -ENOENT
to its caller (and made it assume there were always 0 extrefs).

This issue has been present since the introduction of the extrefs feature
(2012).

A test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:04 -08:00
Filipe Manana d36808e0d4 Btrfs: fix directory inconsistency after fsync log replay
If we have an inode (file) with a link count greater than 1, remove
one of its hard links, fsync the inode, power fail/crash and then
replay the fsync log on the next mount, we end up getting the parent
directory's metadata inconsistent - its i_size still reflects the
deleted hard link and has dangling index entries (with no matching
inode reference entries). This prevents the directory from ever being
deletable, as its i_size can never decrease to BTRFS_EMPTY_DIR_SIZE
even if all of its children inodes are deleted, and the dangling index
entries can never be removed (as they point to an inode that does not
exist anymore).

This is easy to reproduce with the following excerpt from the test case
for xfstests that I just made:

    _scratch_mkfs >> $seqres.full 2>&1

    _init_flakey
    _mount_flakey

    # Create a test file with 2 hard links in the same directory.
    mkdir -p $SCRATCH_MNT/a/b
    echo "hello world" > $SCRATCH_MNT/a/b/foo
    ln $SCRATCH_MNT/a/b/foo $SCRATCH_MNT/a/b/bar

    # Make sure all metadata and data are durably persisted.
    sync

    # Now remove one of the hard links and fsync the inode.
    rm -f $SCRATCH_MNT/a/b/bar
    $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a/b/foo

    # Simulate a crash/power loss. This makes sure the next mount
    # will see an fsync log and will replay that log.

    _load_flakey_table $FLAKEY_DROP_WRITES
    _unmount_flakey

    _load_flakey_table $FLAKEY_ALLOW_WRITES
    _mount_flakey

    # Remove the last hard link of the file and attempt to remove its parent
    # directory - this failed in btrfs because the fsync log and replay code
    # didn't decrement the parent directory's i_size and left dangling directory
    # index entries - this made the btrfs rmdir implementation always fail with
    # the error -ENOTEMPTY.
    #
    # The dangling directory index entries were visible to user space, but it was
    # impossible to do anything on them (unlink, open, read, write, stat, etc)
    # because the inode they pointed to did not exist anymore.
    #
    # The parent directory's metadata inconsistency (stale index entries) was
    # also detected by btrfs' fsck tool, which is run automatically by the fstests
    # framework when the test finishes. The error message reported by fsck was:
    #
    # root 5 inode 259 errors 2001, no inode item, link count wrong
    #   unresolved ref dir 258 index 3 namelen 3 name bar filetype 1 errors 4, no inode ref
    #
    rm -f $SCRATCH_MNT/a/b/*
    rmdir $SCRATCH_MNT/a/b
    rmdir $SCRATCH_MNT/a

To fix this just make sure that after an unlink, if the inode is fsync'ed,
he parent inode is fully logged in the fsync log.

A test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:04 -08:00
Filipe Manana 6219872dc6 Btrfs: lookup for block group only if needed when freeing a tree block
Very often our extent buffer's header generation doesn't match the current
transaction's id or it is also referenced by other trees (snapshots), so
we don't need the corresponding block group cache object. Therefore only
search for it if we are going to use it, so we avoid an unnecessary search
in the block groups rbtree (and acquiring and releasing its spinlock).

Freeing a tree block is performed when COWing or deleting a node/leaf,
which implies we are holding the node/leaf's parent node lock, therefore
reducing the amount of time spent when freeing a tree block helps reducing
the amount of time we are holding the parent node's lock.

For example, for a run of xfstests/generic/083, the block group cache
object was needed only 682 times for a total of 226691 calls to free
a tree block.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:04 -08:00
David Sterba 730a78c741 btrfs: remove a no-op unfreeze superbock callback
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:04 -08:00
David Sterba 9ee49a047d btrfs: switch extent_state state to unsigned
Currently there's a 4B hole in the structure between refs and state and there
are only 16 bits used so we can make it unsigned. This will get a better
packing and may save some stack space for local variables.

The size of extent_state gets reduced by 8B and there are usually a lot
of slab objects.

struct extent_state {
	u64                        start;                /*     0     8 */
	u64                        end;                  /*     8     8 */
	struct rb_node             rb_node;              /*    16    24 */
	wait_queue_head_t          wq;                   /*    40    24 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	atomic_t                   refs;                 /*    64     4 */

	/* XXX 4 bytes hole, try to pack */

	long unsigned int          state;                /*    72     8 */
	u64                        private;              /*    80     8 */

	/* size: 88, cachelines: 2, members: 7 */
	/* sum members: 84, holes: 1, sum holes: 4 */
	/* last cacheline: 24 bytes */
};

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:04 -08:00
David Sterba 5efa0490cc btrfs: set proper message level for skinny metadata
This has been confusing people for too long, the message is really just
informative.

CC: <stable@vger.kernel.org> # 3.10+
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:03 -08:00
David Sterba f0954c6637 btrfs: update message levels after checksum errors
The errors are worth noting and might get missed with INFO level.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:03 -08:00
David Sterba aa8ee31209 btrfs: update message levels during failed mount
All error conditions from open_ctree shall be ERR. Warning would
suggest that something's wrong and we can continue.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:03 -08:00
David Sterba 68b663d13c btrfs: update message levels for errors
Several messages that point to some internal problem, level INFO is
wrong here.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:03 -08:00
Filipe Manana a8df6fe666 Btrfs: fix setup_leaf_for_split() to avoid leaf corruption
We were incorrectly detecting when the target key didn't exist anymore
after releasing the path and re-searching the tree. This could make
us split or duplicate (btrfs_split_item() and btrfs_duplicate_item()
are its only callers at the moment) an item when we should not.

For the case of duplicating an item, we currently only duplicate
checksum items (csum tree) and file extent items (fs/subvol trees).
For the checksum items we end up overriding the item completely,
but for file extent items we update only some of their fields in
the copy (done in __btrfs_drop_extents), which means we can end up
having a logical corruption for some values.

Also for the case where we duplicate a file extent item it will make
us produce a leaf with a wrong key order, as btrfs_duplicate_item()
advances us to the next slot and then its caller sets a smaller key
on the new item at that slot (like in __btrfs_drop_extents() e.g.).
Alternatively if the tree search in setup_leaf_for_split() leaves
with path->slots[0] == btrfs_header_nritems(path->nodes[0]), we end
up accessing beyond the leaf's end (when we check if the item's size
has changed) and make our caller insert an item at the invalid slot
btrfs_header_nritems(path->nodes[0]) + 1, causing an invalid memory
access if the leaf is full or nearly full.

This issue has been present since the introduction of this function
in 2009:

    Btrfs: Add btrfs_duplicate_item
    commit ad48fd7546

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:02:03 -08:00
Chris Mason 57bbddd7fb Merge branch 'cleanup/blocksize-diet-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus 2015-01-21 17:49:35 -08:00
Chris Mason d354183488 Merge branch 'fix/find-item-path-leak' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus 2015-01-21 17:45:25 -08:00
Josef Bacik ce93ec548c Btrfs: track dirty block groups on their own list
Currently any time we try to update the block groups on disk we will walk _all_
block groups and check for the ->dirty flag to see if it is set.  This function
can get called several times during a commit.  So if you have several terabytes
of data you will be a very sad panda as we will loop through _all_ of the block
groups several times, which makes the commit take a while which slows down the
rest of the file system operations.

This patch introduces a dirty list for the block groups that we get added to
when we dirty the block group for the first time.  Then we simply update any
block groups that have been dirtied since the last time we called
btrfs_write_dirty_block_groups.  This allows us to clean up how we write the
free space cache out so it is much cleaner.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 17:36:52 -08:00
Josef Bacik e7070be198 Btrfs: change how we track dirty roots
I've been overloading root->dirty_list to keep track of dirty roots and which
roots need to have their commit roots switched at transaction commit time.  This
could cause us to lose an update to the root which could corrupt the file
system.  To fix this use a state bit to know if the root is dirty, and if it
isn't set we go ahead and move the root to the dirty list.  This way if we
re-dirty the root after adding it to the switch_commit list we make sure to
update it.  This also makes it so that the extent root is always the last root
on the dirty list to try and keep the amount of churn down at this point in the
commit.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 17:35:49 -08:00
Ingo Molnar f49028292c Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

  - Documentation updates.

  - Miscellaneous fixes.

  - Preemptible-RCU fixes, including fixing an old bug in the
    interaction of RCU priority boosting and CPU hotplug.

  - SRCU updates.

  - RCU CPU stall-warning updates.

  - RCU torture-test updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-21 06:12:21 +01:00
Qu Wenruo a53f4f8e9c btrfs: Don't call btrfs_start_transaction() on frozen fs to avoid deadlock.
Commit 6b5fe46dfa (btrfs: do commit in sync_fs if there are pending
changes) will call btrfs_start_transaction() in sync_fs(), to handle
some operations needed to be done in next transaction.

However this can cause deadlock if the filesystem is frozen, with the
following sys_r+w output:
[  143.255932] Call Trace:
[  143.255936]  [<ffffffff816c0e09>] schedule+0x29/0x70
[  143.255939]  [<ffffffff811cb7f3>] __sb_start_write+0xb3/0x100
[  143.255971]  [<ffffffffa040ec06>] start_transaction+0x2e6/0x5a0
[btrfs]
[  143.255992]  [<ffffffffa040f1eb>] btrfs_start_transaction+0x1b/0x20
[btrfs]
[  143.256003]  [<ffffffffa03dc0ba>] btrfs_sync_fs+0xca/0xd0 [btrfs]
[  143.256007]  [<ffffffff811f7be0>] sync_fs_one_sb+0x20/0x30
[  143.256011]  [<ffffffff811cbd01>] iterate_supers+0xe1/0xf0
[  143.256014]  [<ffffffff811f7d75>] sys_sync+0x55/0x90
[  143.256017]  [<ffffffff816c49d2>] system_call_fastpath+0x12/0x17
[  143.256111] Call Trace:
[  143.256114]  [<ffffffff816c0e09>] schedule+0x29/0x70
[  143.256119]  [<ffffffff816c3405>] rwsem_down_write_failed+0x1c5/0x2d0
[  143.256123]  [<ffffffff8133f013>] call_rwsem_down_write_failed+0x13/0x20
[  143.256131]  [<ffffffff811caae8>] thaw_super+0x28/0xc0
[  143.256135]  [<ffffffff811db3e5>] do_vfs_ioctl+0x3f5/0x540
[  143.256187]  [<ffffffff811db5c1>] SyS_ioctl+0x91/0xb0
[  143.256213]  [<ffffffff816c49d2>] system_call_fastpath+0x12/0x17

The reason is like the following:
(Holding s_umount)
VFS sync_fs staff:
|- btrfs_sync_fs()
   |- btrfs_start_transaction()
      |- sb_start_intwrite()
      (Waiting thaw_fs to unfreeze)
					VFS thaw_fs staff:
					thaw_fs()
					(Waiting sync_fs to release
					 s_umount)

So deadlock happens.
This can be easily triggered by fstest/generic/068 with inode_cache
mount option.

The fix is to check if the fs is frozen, if the fs is frozen, just
return and waiting for the next transaction.

Cc: David Sterba <dsterba@suse.cz>
Reported-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[enhanced comment, changed to SB_FREEZE_WRITE]
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-20 17:20:21 -08:00
Qu Wenruo 6c9fe14f9d btrfs: Fix the bug that fs_info->pending_changes is never cleared.
Fs_info->pending_changes is never cleared since the original code uses
cmpxchg(&fs_info->pending_changes, 0, 0), which will only clear it if
pending_changes is already 0.

This will cause a lot of problem when mount it with inode_cache mount
option.
If the btrfs is mounted as inode_cache, pending_changes will always be
1, even when the fs is frozen.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-20 17:19:40 -08:00
Christoph Hellwig df0ce26cb4 fs: remove default_backing_dev_info
Now that default_backing_dev_info is not used for writeback purposes we can
git rid of it easily:

 - instead of using it's name for tracing unregistered bdi we just use
   "unknown"
 - btrfs and ceph can just assign the default read ahead window themselves
   like several other filesystems already do.
 - we can assign noop_backing_dev_info as the default one in alloc_super.
   All filesystems already either assigned their own or
   noop_backing_dev_info.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:05:38 -07:00
Christoph Hellwig b83ae6d421 fs: remove mapping->backing_dev_info
Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:05 -07:00
Christoph Hellwig de1414a654 fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
Now that we got rid of the bdi abuse on character devices we can always use
sb->s_bdi to get at the backing_dev_info for a file, except for the block
device special case.  Export inode_to_bdi and replace uses of
mapping->backing_dev_info with it to prepare for the removal of
mapping->backing_dev_info.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:04 -07:00
Christoph Hellwig b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Satoru Takeuchi 6e1103a6e9 btrfs: fix state->private cast on 32 bit machines
Suppress the following warning displayed on building 32bit (i686) kernel.

===============================================================================
...
   CC [M]  fs/btrfs/extent_io.o
fs/btrfs/extent_io.c: In function ‘btrfs_free_io_failure_record’:
fs/btrfs/extent_io.c:2193:13: warning: cast to pointer from integer of
different size [-Wint-to-pointer-cast]
    failrec = (struct io_failure_record *)state->private;
...
===============================================================================

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Reported-by: Chris Murphy <chris@colorremedies.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-19 13:06:06 -08:00
Filipe Manana 75c68e9fbb Btrfs: fix race deleting block group from space_info->ro_bgs list
When removing a block group we were deleting it from its space_info's
ro_bgs list without the correct protection - the space info's spinlock.
Fix this by doing the list delete while holding the spinlock of the
corresponding space info, which is the correct lock for any operation
on that list.

This issue was introduced in the 3.19 kernel by the following change:

    Btrfs: move read only block groups onto their own list V2
    commit 633c0aad4c

I ran into a kernel crash while a task was running statfs, which iterates
the space_info->ro_bgs list while holding the space info's spinlock,
and another task was deleting it from the same list, without holding that
spinlock, as part of the block group remove operation (while running the
function btrfs_remove_block_group). This happened often when running the
stress test xfstests/generic/038 I recently made.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-19 13:05:45 -08:00
Tsutomu Itoh 379d6854a2 Btrfs: fix incorrect freeing in scrub_stripe
The address that should be freed is not 'ppath' but 'path'.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Reviewed-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-19 13:05:44 -08:00
David Sterba 98bd5c547e btrfs: sync ioctl, handle errors after transaction start
The version merged to 3.19 did not handle errors from start_trancaction
and could pass an invalid pointer to commit_transaction.

Fixes: 6b5fe46dfa ("btrfs: do commit in sync_fs if there are pending changes")
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-19 13:05:44 -08:00
David Sterba 1d4c08e0a6 btrfs: expand btrfs_find_item if found_key is NULL
If the found_key is NULL, then btrfs_find_item becomes a verbose wrapper
for simple btrfs_search_slot.

After we've removed all such callers, passing a NULL key is not valid
anymore.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-14 19:23:48 +01:00
David Sterba 9c4f61f01d btrfs: simplify insert_orphan_item
We can search and add the orphan item in one go,
btrfs_insert_orphan_item will find out if the item already exists.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-14 19:23:48 +01:00