Commit Graph

722 Commits

Author SHA1 Message Date
Anand Jain 2365dd3ca0 btrfs: undo sysfs when open_ctree() fails
reproducer:
mkfs.btrfs -f /dev/sdb &&\
mount /dev/sdb /btrfs &&\
btrfs dev add -f /dev/sdc /btrfs &&\
umount /btrfs &&\
wipefs -a /dev/sdc &&\
mount -o degraded /dev/sdb /btrfs
//above mount fails so try with RO
mount -o degraded,ro /dev/sdb /btrfs

------
sysfs: cannot create duplicate filename '/fs/btrfs/3f48c79e-5ed0-4e87-b189-86e749e503f4'
::

dump_stack+0x49/0x5e
warn_slowpath_common+0x87/0xb0
warn_slowpath_fmt+0x41/0x50
strlcat+0x69/0x80
sysfs_warn_dup+0x87/0xa0
sysfs_add_one+0x40/0x50
create_dir+0x76/0xc0
sysfs_create_dir_ns+0x7a/0xc0
kobject_add_internal+0xad/0x220
kobject_add_varg+0x38/0x60
kobject_init_and_add+0x53/0x70
mutex_lock+0x11/0x40
__free_pages+0x25/0x30
free_pages+0x41/0x50
selinux_sb_copy_data+0x14e/0x1e0
mount_fs+0x3e/0x1a0
vfs_kern_mount+0x71/0x120
do_mount+0x3f7/0x980
SyS_mount+0x8b/0xe0
system_call_fastpath+0x16/0x1b
------

further 'modprobe -r btrfs' fails as well

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:44 -08:00
Liu Bo 1a4319cc3c Btrfs: fix extent state leak on transaction abortion
When transaction is aborted, we fail to commit transaction, instead we do
cleanup work.  After that when we umount btrfs, we get to free fs roots' log
trees respectively, but that happens after we unpin extents, so those extents
pinned by freeing log trees will remain in memory and lead to the leak.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:35 -08:00
Qu Wenruo 3818aea275 btrfs: Add noinode_cache mount option
Add noinode_cache mount option for btrfs.

Since inode map cache involves all the btrfs_find_free_ino/return_ino
things and if just trigger the mount_opt,
an inode number get from inode map cache will not returned to inode map
cache.

To keep the find and return inode both in the same behavior,
a new bit in mount_opt, CHANGE_INODE_CACHE, is introduced for this idea.
CHANGE_INODE_CACHE is set/cleared in remounting, and the original
INODE_MAP_CACHE is set/cleared according to CHANGE_INODE_CACHE after a
success transaction.
Since find/return inode is all done between btrfs_start_transaction and
btrfs_commit_transaction, this will keep consistent behavior.

Also noinode_cache mount option will not stop the caching_kthread.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:33 -08:00
Josef Bacik 0a2b2a844a Btrfs: throttle delayed refs better
On one of our gluster clusters we noticed some pretty big lag spikes.  This
turned out to be because our transaction commit was taking like 3 minutes to
complete.  This is because we have like 30 gigs of metadata, so our global
reserve would end up being the max which is like 512 mb.  So our throttling code
would allow a ridiculous amount of delayed refs to build up and then they'd all
get run at transaction commit time, and for a cold mounted file system that
could take up to 3 minutes to run.  So fix the throttling to be based on both
the size of the global reserve and how long it takes us to run delayed refs.
This patch tracks the time it takes to run delayed refs and then only allows 1
seconds worth of outstanding delayed refs at a time.  This way it will auto-tune
itself from cold cache up to when everything is in memory and it no longer has
to go to disk.  This makes our transaction commits take much less time to run.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:26 -08:00
Josef Bacik d7df2c796d Btrfs: attach delayed ref updates to delayed ref heads
Currently we have two rb-trees, one for delayed ref heads and one for all of the
delayed refs, including the delayed ref heads.  When we process the delayed refs
we have to hold onto the delayed ref lock for all of the selecting and merging
and such, which results in quite a bit of lock contention.  This was solved by
having a waitqueue and only one flusher at a time, however this hurts if we get
a lot of delayed refs queued up.

So instead just have an rb tree for the delayed ref heads, and then attach the
delayed ref updates to an rb tree that is per delayed ref head.  Then we only
need to take the delayed ref lock when adding new delayed refs and when
selecting a delayed ref head to process, all the rest of the time we deal with a
per delayed ref head lock which will be much less contentious.

The locking rules for this get a little more complicated since we have to lock
up to 3 things to properly process delayed refs, but I will address that problem
later.  For now this passes all of xfstests and my overnight stress tests.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:25 -08:00
Wang Shilong e8117c26b2 Btrfs: only fua the first superblock when writting supers
We only intent to fua the first superblock in every device from
comments, fix it.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:15 -08:00
Frank Holton efe120a067 Btrfs: convert printk to btrfs_ and fix BTRFS prefix
Convert all applicable cases of printk and pr_* to the btrfs_* macros.

Fix all uses of the BTRFS prefix.

Signed-off-by: Frank Holton <fholton@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:20:05 -08:00
Josef Bacik f28491e0a6 Btrfs: move the extent buffer radix tree into the fs_info
I need to create a fake tree to test qgroups and I don't want to have to setup a
fake btree_inode.  The fact is we only use the radix tree for the fs_info, so
everybody else who allocates an extent_io_tree is just wasting the space anyway.
This patch moves the radix tree and its lock into btrfs_fs_info so there is less
stuff I have to fake to do qgroup sanity tests.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:19:55 -08:00
Kelley Nielsen 3f870c2899 btrfs: expand btrfs_find_item() to include find_orphan_item functionality
This is the third step in bootstrapping the btrfs_find_item interface.
The function find_orphan_item(), in orphan.c, is similar to the two
functions already replaced by the new interface. It uses two parameters,
which are already present in the interface, and is nearly identical to
the function brought in in the previous patch.

Replace the two calls to find_orphan_item() with calls to
btrfs_find_item(), with the defined objectid and type that was used
internally by find_orphan_item(), a null path, and a null key. Add a
test for a null path to btrfs_find_item, and if it passes, allocate and
free the path. Finally, remove find_orphan_item().

Signed-off-by: Kelley Nielsen <kelleynnn@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:19:37 -08:00
Valentina Giusti 71db2a7751 btrfs: remove unused variables from disk-io.c
Remove unused variables:
* tree from csum_dirty_buffer,
* tree from btree_readpage_end_io_hook,
* tree from btree_writepages,
* bytenr from btrfs_create_tree,
* fs_info from end_workqueue_fn.

Signed-off-by: Valentina Giusti <valentina.giusti@microon.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:19:31 -08:00
Jeff Mahoney 5ac1d209f1 btrfs: publish per-super attributes in sysfs
This patch adds per-super attributes to sysfs.

It doesn't publish any attributes yet, but does the proper lifetime
handling as well as the basic infrastructure to add new attributes.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:19:25 -08:00
Liu Bo c46effa601 Btrfs: introduce a head ref rbtree
The way how we process delayed refs is
1) get a bunch of head refs,
2) pick up one head ref,
3) go one node back for any delayed ref updates.

The head ref is also linked in the same rbtree as the delayed ref is,
so in 1) stage, we have to walk one by one including not only head refs, but
delayed refs.

When we have a great number of delayed refs pending to process,
this'll cost time a lot.

Here we introduce a head ref specific rbtree, it only has head refs, so troubles
go away.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28 13:19:22 -08:00
Liu Bo d52c1bcc64 Btrfs: avoid heavy operations in btrfs_commit_super
The 'git blame' history shows that, the old transaction commit code has to do
twice to ensure roots are updated and we have to flush metadata and super block
manually, however, right now all of these can be handled well inside
the transaction commit code without extra efforts.

And the error handling part remains same with the current code, -- 'return to
caller once we get error'.

This saves us a transaction commit and a flush of super block, which are both
heavy operations according to ftrace output analysis.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-20 20:42:16 -05:00
Rashika f570e757b5 btrfs: Remove useless variable in write_ctree_super()
The function write_ctree_super() in disk-io.c uses variable ret to return
the result of function write_all_supers(). Since, this variable serves
no purpose, hence the patch removes it and returns the call of the
called function.

Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 22:12:40 -05:00
Dulshani Gunawardhana fae7f21cec btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)
Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source
code that outputs a more descriptive warnings. Also fix the styling
warning of redundant braces that came up as a result of this fix.

Signed-off-by: Dulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 22:11:53 -05:00
Rashika 2e9f595497 btrfs: Add helper function for free_root_pointers()
The function free_root_pointers() in disk-io.h contains redundant code.
Therefore, this patch adds a helper function free_root_extent_buffers()
to free_root_pointers() to eliminate redundancy.

Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 22:11:13 -05:00
Wang Shilong 9b011adfe1 Btrfs: remove scrub_super_lock holding in btrfs_sync_log()
Originally, we introduced scrub_super_lock to synchronize
tree log code with scrubbing super.

However we can replace scrub_super_lock with device_list_mutex,
because writing super will hold this mutex, this will reduce an extra
lock holding when writing supers in sync log code.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 22:10:13 -05:00
Zach Brown 8b558c5f09 btrfs: remove fs/btrfs/compat.h
fs/btrfs/compat.h only contained trivial macro wrappers of drop_nlink()
and inc_nlink().  This doesn't belong in mainline.

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 22:03:19 -05:00
Chandra Seetharaman 452c75c3d2 Btrfs: Simplify the logic in alloc_extent_buffer() for existing extent buffer case
alloc_extent_buffer() uses radix_tree_lookup() when radix_tree_insert()
fails with EEXIST. That part of the code is very similar to the code in
find_extent_buffer(). This patch replaces radix_tree_lookup() and
surrounding code in alloc_extent_buffer() with find_extent_buffer().

Note that radix_tree_lookup() does not need to be protected by
tree->buffer_lock. It is protected by eb->refs.

While at it, this patch
  - changes the other usage of radix_tree_lookup() in alloc_extent_buffer()
    with find_extent_buffer() to reduce redundancy.
  - removes the unused argument 'len' to find_extent_buffer().

Signed-Off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Zach Brown <zab@redhat.com>

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:59:11 -05:00
Josef Bacik 96192499c2 Btrfs: stop all workers after we free block groups
Stefan was hitting a panic in the async worker stuff because we had outstanding
read bios while we were stopping the worker threads.  You could reproduce this
easily if you mount -o nospace_cache and ran generic/273.  This is because the
caching thread stuff is still going and we were stopping all the worker threads.
We need to stop the workers after this work is done, and the free block groups
code will wait for all the caching threads to stop first so we don't run into
this problem.  With this patch we no longer panic.  Thanks,

Cc: stable@vger.kernel.org
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:57:49 -05:00
Josef Bacik 2b1360da35 Btrfs: free up block groups after everything
If we abort a transaction we will do the tree log cleanup at unmount, but this
happens after we free up the block groups.  This makes all the leak detection
warnings go off because we think we've leaked space but in reality we just
haven't cleaned it up yet.  So instead do the block group cleanup stuff after
free'ing the fs roots so we don't get these warnings.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:56:17 -05:00
Josef Bacik eb58bb371a Btrfs: do not free the dirty bytes from the trans block rsv on cleanup
The transactions should be cleaning up their reservations on failure, this just
causes us to have warnings on unmount because we go negative by free'ing
reservations that have already been free'ed.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:55:58 -05:00
Filipe David Borba Manana 778ba82b17 Btrfs: improve inode hash function/inode lookup
Currently the hash value used for adding an inode to the VFS's inode
hash table consists of the plain inode number, which is a 64 bits
integer. This results in hash table buckets (hlist_head lists) with
too many elements for at least 2 important scenarios:

1) When we have many subvolumes. Each subvolume has its own btree
   where its files and directories are added to, and each has its
   own objectid (inode number) namespace. This means that if we have
   N subvolumes, and all have inode number X associated to a file or
   directory, the corresponding inodes all map to the same hash table
   entry, resulting in a bucket (hlist_head list) with N elements;

2) On 32 bits machines. Th VFS hash values are unsigned longs, which
   are 32 bits wide on 32 bits machines, and the inode (objectid)
   numbers are 64 bits unsigned integers. We simply cast the inode
   numbers to hash values, which means that for all inodes with the
   same 32 bits lower half, the same hash bucket is used for all of
   them. For example, all inodes with a number (objectid) between
   0x0000_0000_ffff_ffff and 0xffff_ffff_ffff_ffff will end up in
   the same hash table bucket.

This change ensures the inode's hash value depends both on the
objectid (inode number) and its subvolume's (btree root) objectid.
For 32 bits machines, this change gives better entropy by making
the hash value depend on both the upper and lower 32 bits of the
64 bits hash previously computed.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:55:19 -05:00
Ross Kirk 0a4e558609 btrfs: remove unused parameter from btrfs_header_fsid
Remove unused parameter, 'eb'. Unused since introduction in
5f39d397df

Updated to be rebased against current upstream and correct diff supplied this time!

Signed-off-by: Ross Kirk <ross.kirk@gmail.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:54:16 -05:00
Josef Bacik 724e2315db Btrfs: fix two use-after-free bugs with transaction cleanup
I was noticing the slab redzone stuff going off every once and a while during
transaction aborts.  This was caused by two things

1) We would walk the pending snapshots and set their error to -ECANCELED.  We
don't need to do this, the snapshot stuff waits for a transaction commit and if
there is a problem we just free our pending snapshot object and exit.  Doing
this was causing us to touch the pending snapshot object after the thing had
already been freed.

2) We were freeing the transaction manually with wanton disregard for it's
use_count reference counter.  To fix this I cleaned up the transaction freeing
loop to either wait for the transaction commit to finish if it was in the middle
of that (since it will be cleaned and freed up there) or to do the cleanup
oursevles.

I also moved the global "kill all things dirty everywhere" stuff outside of the
transaction cleanup loop since that only needs to be done once.  With this patch
I'm no longer seeing slab corruption because of use after frees.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:54:03 -05:00
Josef Bacik 1de2cfde93 Btrfs: don't delete ordered roots from list during cleanup
During transaction cleanup after an abort we are just removing roots from the
ordered roots list which is incorrect.  We have a BUG_ON() to make sure that the
root is still part of the ordered roots list when we put our ordered extent
which we were tripping in this case.  So do like we do everywhere else and just
move it to the tail of the ordered roots list and allow the normal cleanup to
take care of stuff.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:53:49 -05:00
Josef Bacik 4e121c06ad Btrfs: cleanup transaction on abort
If we abort not during a transaction commit we won't clean up anything until we
unmount.  Unfortunately if we abort in the middle of writing out an ordered
extent we won't clean it up and if somebody is waiting on that ordered extent
they will wait forever.  To fix this just make the transaction kthread call the
cleanup transaction stuff if it notices theres an error, and make
btrfs_end_transaction wake up the transaction kthread if there is an error.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:53:42 -05:00
Josef Bacik 06ea65a398 Btrfs: add a sanity test for btrfs_split_item
While looking at somebodys corruption I became completely convinced that
btrfs_split_item was broken, so I wrote this test to verify that it was working
as it was supposed to.  Thankfully it appears to be working as intended, so just
add this test to make sure nobody breaks it in the future.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:51:02 -05:00
Stefan Behrens 69e9c6c6dc Btrfs: eliminate the exceptional root_tree refs=0
The fact that btrfs_root_refs() returned 0 for the tree_root caused
bugs in the past, therefore it is set to 1 with this patch and
(hopefully) all affected code is adapted to this change.

I verified this change by temporarily adding WARN_ON() checks
everywhere where btrfs_root_refs() is used, checking whether the
logic of the code is changed by btrfs_root_refs() returning 1
instead of 0 for root->root_key.objectid == BTRFS_ROOT_TREE_OBJECTID.
With these added checks, I ran the xfstests './check -g auto'.

The two roots chunk_root and log_root_tree that are only referenced
by the superblock and the log_roots below the log_root_tree still
have btrfs_root_refs() == 0, only the tree_root is changed.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-11 21:49:26 -05:00
Miao Xie c00869f1ae Btrfs: fix oops caused by the space balance and dead roots
When doing space balance and subvolume destroy at the same time, we met
the following oops:

kernel BUG at fs/btrfs/relocation.c:2247!
RIP: 0010: [<ffffffffa04cec16>] prepare_to_merge+0x154/0x1f0 [btrfs]
Call Trace:
 [<ffffffffa04b5ab7>] relocate_block_group+0x466/0x4e6 [btrfs]
 [<ffffffffa04b5c7a>] btrfs_relocate_block_group+0x143/0x275 [btrfs]
 [<ffffffffa0495c56>] btrfs_relocate_chunk.isra.27+0x5c/0x5a2 [btrfs]
 [<ffffffffa0459871>] ? btrfs_item_key_to_cpu+0x15/0x31 [btrfs]
 [<ffffffffa048b46a>] ? btrfs_get_token_64+0x7e/0xcd [btrfs]
 [<ffffffffa04a3467>] ? btrfs_tree_read_unlock_blocking+0xb2/0xb7 [btrfs]
 [<ffffffffa049907d>] btrfs_balance+0x9c7/0xb6f [btrfs]
 [<ffffffffa049ef84>] btrfs_ioctl_balance+0x234/0x2ac [btrfs]
 [<ffffffffa04a1e8e>] btrfs_ioctl+0xd87/0x1ef9 [btrfs]
 [<ffffffff81122f53>] ? path_openat+0x234/0x4db
 [<ffffffff813c3b78>] ? __do_page_fault+0x31d/0x391
 [<ffffffff810f8ab6>] ? vma_link+0x74/0x94
 [<ffffffff811250f5>] vfs_ioctl+0x1d/0x39
 [<ffffffff811258c8>] do_vfs_ioctl+0x32d/0x3e2
 [<ffffffff811259d4>] SyS_ioctl+0x57/0x83
 [<ffffffff813c3bfa>] ? do_page_fault+0xe/0x10
 [<ffffffff813c73c2>] system_call_fastpath+0x16/0x1b

It is because we returned the error number if the reference of the root was 0
when doing space relocation. It was not right here, because though the root
was dead(refs == 0), but the space it held still need be relocated, or we
could not remove the block group. So in this case, we should return the root
no matter it is dead or not.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-10-10 21:31:02 -04:00
Stefan Behrens a724b43690 Btrfs: add the missing mutex unlock in write_all_supers()
The BUG() was replaced by btrfs_error() and return -EIO with the
patch "get rid of one BUG() in write_all_supers()", but the missing
mutex_unlock() was overlooked.

The 0-DAY kernel build service from Intel reported the missing
unlock which was found by the coccinelle tool:

    fs/btrfs/disk-io.c:3422:2-8: preceding lock on line 3374

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-21 11:05:28 -04:00
David Sterba 13fd8da98f btrfs: add lockdep and tracing annotations for uuid tree
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-21 10:58:56 -04:00
Josef Bacik 45d5fd14d2 Btrfs: don't use an async starter for most of our workers
We only need an async starter if we can't make a GFP_NOFS allocation in our
current path.  This is the case for the endio stuff since it happens in IRQ
context, but things like the caching thread workers and the delalloc flushers we
can easily make this allocation and start threads right away.  Also change the
worker count for the caching thread pool.  Traditionally we limited this to 2
since we took read locks while caching, but nowadays we do this lockless so
there's no reason to limit the number of caching threads.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:41 -04:00
Stefan Behrens 4847547172 Btrfs: fix for patch "cleanup: don't check the same thing twice"
Mitch Harder noticed that the patch 3c64a1a mentioned in the subject
line was causing a kernel BUG() on snapshot deletion.

The patch was wrong. It did not handle cached roots correctly. The
check for root_refs == 0 was removed everywhere where
btrfs_read_fs_root_no_name() had been used to retrieve the root,
because this check was already dealt with in
btrfs_read_fs_root_no_name(). But in the case when the root was
found in the cache, there was no such check.

This patch adds the missing check in the case where the root is
found in the cache.

Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:29 -04:00
Stefan Behrens 9d565ba433 Btrfs: get rid of one BUG() in write_all_supers()
The second round uses btrfs_error() and return -EIO, the first round
can handle write errors the same way.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:28 -04:00
Filipe David Borba Manana d730680184 Btrfs: fix race between removing a dev and writing sbs
This change fixes an issue when removing a device and writing
all super blocks run simultaneously. Here's the steps necessary
for the issue to happen:

1) disk-io.c:write_all_supers() gets a number of N devices from the
   super_copy, so it will not panic if it fails to write super blocks
   for N - 1 devices;

2) Then it tries to acquire the device_list_mutex, but blocks because
   volumes.c:btrfs_rm_device() got it first;

3) btrfs_rm_device() removes the device from the list, then unlocks the
   mutex and after the unlock it updates the number of devices in
   super_copy to N - 1.

4) write_all_supers() finally acquires the mutex, iterates over all the
   devices in the list and gets N - 1 errors, that is, it failed to write
   super blocks to all the devices;

5) Because write_all_supers() thinks there are a total of N devices, it
   considers N - 1 errors to be ok, and therefore won't panic.

So this change just makes sure that write_all_supers() reads the number
of devices from super_copy after it acquires the device_list_mutex.
Conversely, it changes btrfs_rm_device() to update the number of devices
in super_copy before it releases the device list mutex.

The code path to add a new device (volumes.c:btrfs_init_new_device),
already has the right behaviour: it updates the number of devices in
super_copy while holding the device_list_mutex.

The only code path that doesn't lock the device list mutex
before updating the number of devices in the super copy is
disk-io.c:next_root_backup(), called by open_ctree() during
mount time where concurrency issues can't happen.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:24 -04:00
Geert Uytterhoeven b308bc2f05 Btrfs: Make btrfs_header_chunk_tree_uuid() return unsigned long
Internally, btrfs_header_chunk_tree_uuid() calculates an unsigned long, but
casts it to a pointer, while all callers cast it to unsigned long again.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:16 -04:00
Geert Uytterhoeven fba6aa7565 Btrfs: Make btrfs_header_fsid() return unsigned long
Internally, btrfs_header_fsid() calculates an unsigned long, but casts
it to a pointer, while all callers cast it to unsigned long again.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:15 -04:00
Geert Uytterhoeven c1c9ff7c94 Btrfs: Remove superfluous casts from u64 to unsigned long long
u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:08 -04:00
Filipe David Borba Manana 1cb048f596 Btrfs: fix memory leak of orphan block rsv
This issue is simple to reproduce and observe if kmemleak is enabled.
Two simple ways to reproduce it:

** 1

$ mkfs.btrfs -f /dev/loop0
$ mount /dev/loop0 /mnt/btrfs
$ btrfs balance start /mnt/btrfs
$ umount /mnt/btrfs

** 2

$ mkfs.btrfs -f /dev/loop0
$ mount /dev/loop0 /mnt/btrfs
$ touch /mnt/btrfs/foobar
$ rm -f /mnt/btrfs/foobar
$ umount /mnt/btrfs

After a while, kmemleak reports the leak:

$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff880402b13e00 (size 128):
  comm "btrfs", pid 19621, jiffies 4341648183 (age 70057.844s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 fc c6 b1 04 88 ff ff 04 00 04 00 ad 4e ad de  .............N..
  backtrace:
    [<ffffffff817275a6>] kmemleak_alloc+0x26/0x50
    [<ffffffff8117832b>] kmem_cache_alloc_trace+0xeb/0x1d0
    [<ffffffffa04db499>] btrfs_alloc_block_rsv+0x39/0x70 [btrfs]
    [<ffffffffa04f8bad>] btrfs_orphan_add+0x13d/0x1b0 [btrfs]
    [<ffffffffa04e2b13>] btrfs_remove_block_group+0x143/0x500 [btrfs]
    [<ffffffffa0518158>] btrfs_relocate_chunk.isra.63+0x618/0x790 [btrfs]
    [<ffffffffa051bc27>] btrfs_balance+0x8f7/0xe90 [btrfs]
    [<ffffffffa05240a0>] btrfs_ioctl_balance+0x250/0x550 [btrfs]
    [<ffffffffa05269ca>] btrfs_ioctl+0xdfa/0x25f0 [btrfs]
    [<ffffffff8119c936>] do_vfs_ioctl+0x96/0x570
    [<ffffffff8119cea1>] SyS_ioctl+0x91/0xb0
    [<ffffffff81750242>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff

This affects btrfs-next, revision be8e3cd00d7293dd177e3f8a4a1645ce09ca3acb
(Btrfs: separate out tests into their own directory).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:16:07 -04:00
Stefan Behrens f420ee1e92 Btrfs: add mount option to force UUID tree checking
This should never be needed, but since all functions are there
to check and rebuild the UUID tree, a mount option is added that
allows to force this check and rebuild procedure.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:59 -04:00
Stefan Behrens 70f8017547 Btrfs: check UUID tree during mount if required
If the filesystem was mounted with an old kernel that was not
aware of the UUID tree, this is detected by looking at the
uuid_tree_generation field of the superblock (similar to how
the free space cache is doing it). If a mismatch is detected
at mount time, a thread is started that does two things:
1. Iterate through the UUID tree, check each entry, delete those
   entries that are not valid anymore (i.e., the subvol does not
   exist anymore or the value changed).
2. Iterate through the root tree, for each found subvolume, add
   the UUID tree entries for the subvolume (if they are not
   already there).

This mechanism is also used to handle and repair errors that
happened during the initial creation and filling of the tree.
The update of the uuid_tree_generation field (which indicates
that the state of the UUID tree is up to date) is blocked until
all create and repair operations are successfully completed.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:58 -04:00
Stefan Behrens 803b2f54fb Btrfs: fill UUID tree initially
When the UUID tree is initially created, a task is spawned that
walks through the root tree. For each found subvolume root_item,
the uuid and received_uuid entries in the UUID tree are added.
This is such a quick operation so that in case somebody wants
to unmount the filesystem while the task is still running, the
unmount is delayed until the UUID tree building task is finished.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:56 -04:00
Stefan Behrens f7a81ea4cc Btrfs: create UUID tree if required
This tree is not created by mkfs.btrfs. Therefore when a filesystem
is mounted writable and the UUID tree does not exist, this tree is
created if required. The tree is also added to the fs_info structure
and initialized, but this commit does not yet read or write UUID tree
elements.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:54 -04:00
Sergei Trofimovich 171170c1c5 btrfs: mark some local function as 'static'
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:51 -04:00
Stefan Behrens 35a3621beb Btrfs: get rid of sparse warnings
make C=2 fs/btrfs/ CF=-D__CHECK_ENDIAN__

I tried to filter out the warnings for which patches have already
been sent to the mailing list, pending for inclusion in btrfs-next.

All these changes should be obviously safe.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:15:50 -04:00
Josef Bacik 9ffba8cda9 Btrfs: fix heavy delalloc related deadlock
I added a patch where we started taking the ordered operations mutex when we
waited on ordered extents.  We need this because we splice the list and process
it, so if a flusher came in during this scenario it would think the list was
empty and we'd usually get an early ENOSPC.  The problem with this is that this
lock is used in transaction committing.  So we end up with something like this

Transaction commit
	-> wait on writers

Delalloc flusher
	-> run_ordered_operations (holds mutex)
		->wait for filemap-flush to do its thing

flush task
	-> cow_file_range
		->wait on btrfs_join_transaction because we're commiting

some other task
	-> commit_transaction because we notice trans->transaction->flush is set
		-> run_ordered_operations (hang on mutex)

We need to disentangle the ordered operations flushing from the delalloc
flushing, since they are separate things.  This solves the deadlock issue I was
seeing.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:05:04 -04:00
David Sterba 8b87dc17fb btrfs: add mount option to set commit interval
I'ts hardcoded to 30 seconds which is fine for most users. Higher values
defer data being synced to permanent storage with obvious consequences
when the system crashes. The upper bound is not forced, but a warning is
printed if it's more than 300 seconds (5 minutes).

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:04:51 -04:00
Filipe David Borba Manana 0f0fe8f710 Btrfs: add missing error handling to read_tree_block
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:04:46 -04:00
Anand Jain 8068a47e2a btrfs: use BTRFS_SUPER_INFO_SIZE macro at btrfs_read_dev_super()
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01 08:04:37 -04:00