Commit Graph

2522 Commits

Author SHA1 Message Date
Jan Kara e7848683ae btrfs: Push mnt_want_write() outside of i_mutex
When mnt_want_write() starts to handle freezing it will get a full lock
semantics requiring proper lock ordering. So push mnt_want_write() call
consistently outside of i_mutex.

CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 01:02:51 +04:00
Al Viro 11e62a8fab btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-23 00:01:43 +04:00
David Howells 9249e17fe0 VFS: Pass mount flags to sget()
Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:34 +04:00
Al Viro ebfc3b49a7 don't pass nameidata to ->create()
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:47 +04:00
Al Viro 00cd8dd3bf stop passing nameidata to ->lookup()
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:32 +04:00
Al Viro b3d9b7a3c7 vfs: switch i_dentry/d_alias to hlist
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:32:55 +04:00
Linus Torvalds 5eecb9cc90 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "I held off on my rc5 pull because I hit an oops during log recovery
  after a crash.  I wanted to make sure it wasn't a regression because
  we have some logging fixes in here.

  It turns out that a commit during the merge window just made it much
  more likely to trigger directory logging instead of full commits,
  which exposed an old bug.

  The new backref walking code got some additional fixes.  This should
  be the final set of them.

  Josef fixed up a corner where our O_DIRECT writes and buffered reads
  could expose old file contents (not stale, just not the most recent).
  He and Liu Bo fixed crashes during tree log recover as well.

  Ilya fixed errors while we resume disk balancing operations on
  readonly mounts."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: run delayed directory updates during log replay
  Btrfs: hold a ref on the inode during writepages
  Btrfs: fix tree log remove space corner case
  Btrfs: fix wrong check during log recovery
  Btrfs: use _IOR for BTRFS_IOC_SUBVOL_GETFLAGS
  Btrfs: resume balance on rw (re)mounts properly
  Btrfs: restore restriper state on all mounts
  Btrfs: fix dio write vs buffered read race
  Btrfs: don't count I/O statistic read errors for missing devices
  Btrfs: resolve tree mod log locking issue in btrfs_next_leaf
  Btrfs: fix tree mod log rewind of ADD operations
  Btrfs: leave critical region in btrfs_find_all_roots as soon as possible
  Btrfs: always put insert_ptr modifications into the tree mod log
  Btrfs: fix tree mod log for root replacements at leaf level
  Btrfs: support root level changes in __resolve_indirect_ref
  Btrfs: avoid waiting for delayed refs when we must not
2012-07-05 13:06:25 -07:00
Chris Mason b6305567e7 Btrfs: run delayed directory updates during log replay
While we are resolving directory modifications in the
tree log, we are triggering delayed metadata updates to
the filesystem btrees.

This commit forces the delayed updates to run so the
replay code can find any modifications done.  It stops
us from crashing because the directory deleltion replay
expects items to be removed immediately from the tree.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
cc: stable@kernel.org
2012-07-02 15:39:19 -04:00
Josef Bacik 7fd1a3f73f Btrfs: hold a ref on the inode during writepages
We can race with unlink and not actually be able to do our igrab in
btrfs_add_ordered_extent.  This will result in all sorts of problems.
Instead of doing the complicated work to try and handle returning an error
properly from btrfs_add_ordered_extent, just hold a ref to the inode during
writepages.  If we cannot grab a ref we know we're freeing this inode anyway
and can just drop the dirty pages on the floor, because screw them we're
going to invalidate them anyway.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-07-02 15:39:18 -04:00
Josef Bacik bdb7d303b3 Btrfs: fix tree log remove space corner case
The tree log stuff can have allocated space that we end up having split
across a bitmap and a real extent.  The free space code does not deal with
this, it assumes that if it finds an extent or bitmap entry that the entire
range must fall within the entry it finds.  This isn't necessarily the case,
so rework the remove function so it can handle this case properly.  This
fixed two panics the user hit, first in the case where the space was
initially in a bitmap and then in an extent entry, and then the reverse
case.  Thanks,

Reported-and-tested-by: Shaun Reich <sreich@kde.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-07-02 15:39:18 -04:00
Liu Bo 6bf02314d9 Btrfs: fix wrong check during log recovery
When we're evicting an inode during log recovery, we need to ensure that the inode
is not in orphan state any more, which means inode's run_time flags has _no_
BTRFS_INODE_HAS_ORPHAN_ITEM.  Thus, the BUG_ON was triggered because of a wrong
check for the flags.

Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-07-02 15:39:17 -04:00
Alexander Block d3a94048c9 Btrfs: use _IOR for BTRFS_IOC_SUBVOL_GETFLAGS
We used the wrong ioctl macro for the getflags ioctl before.
As we don't have the set/getflags ioctls in the user space ioctl.h
at the moment, it's safe to fix it now.

Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-07-02 15:39:17 -04:00
Ilya Dryomov 2b6ba629b5 Btrfs: resume balance on rw (re)mounts properly
This introduces btrfs_resume_balance_async(), which, given that
restriper state was recovered earlier by btrfs_recover_balance(),
resumes balance in btrfs-balance kthread.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-07-02 15:39:17 -04:00
Ilya Dryomov 68310a5e42 Btrfs: restore restriper state on all mounts
Fix a bug that triggered asserts in btrfs_balance() in both normal and
resume modes -- restriper state was not properly restored on read-only
mounts.  This factors out resuming code from btrfs_restore_balance(),
which is now also called earlier in the mount sequence to avoid the
problem of some early writes getting the old profile.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-07-02 15:39:16 -04:00
Josef Bacik c3473e8300 Btrfs: fix dio write vs buffered read race
Miao pointed out there's a problem with mixing dio writes and buffered
reads.  If the read happens between us invalidating the page range and
actually locking the extent we can bring in pages into page cache.  Then
once the write finishes if somebody tries to read again it will just find
uptodate pages and we'll read stale data.  So we need to lock the extent and
check for uptodate bits in the range.  If there are uptodate bits we need to
unlock and invalidate again.  This will keep this race from happening since
we will hold the extent locked until we create the ordered extent, and then
teh read side always waits for ordered extents.  There was also a race in
how we updated i_size, previously we were relying on the generic DIO stuff
to adjust the i_size after the DIO had completed, but this happens outside
of the extent lock which means reads could come in and not see the updated
i_size.  So instead move this work into where we create the extents, and
then this way the update ordered i_size stuff works properly in the endio
handlers.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-07-02 15:36:23 -04:00
Stefan Behrens 597a60fade Btrfs: don't count I/O statistic read errors for missing devices
It is normal behaviour of the low level btrfs function btrfs_map_bio()
to complete a bio with -EIO if the device is missing, instead of just
preventing the bio creation in an earlier step.
This used to cause I/O statistic read error increments and annoying
printk_ratelimited messages. This commit fixes the issue.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reported-by: Carey Underwood <cwillu@cwillu.com>
2012-07-02 15:36:23 -04:00
Jan Schmidt d42244a0d3 Btrfs: resolve tree mod log locking issue in btrfs_next_leaf
With the tree mod log, we may end up with two roots (the current root and a
rewinded version of it) both pointing to two leaves, l1 and l2, of which l2
had already been cow-ed in the current transaction. If we don't rewind any
tree blocks, we cannot have two roots both pointing to an already cowed tree
block.

Now there is btrfs_next_leaf, which has a leaf locked and wants a lock on
the next (right) leaf. And there is push_leaf_left, which has a (cowed!)
leaf locked and wants a lock on the previous (left) leaf.

In order to solve this dead lock situation, we use try_lock in
btrfs_next_leaf (only in case it's called with a tree mod log time_seq
paramter) and if we fail to get a lock on the next leaf, we give up our lock
on the current leaf and retry from the very beginning.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:40 +02:00
Jan Schmidt 19956c7e94 Btrfs: fix tree mod log rewind of ADD operations
When a MOD_LOG_KEY_ADD operation is rewinded, we remove the key from the
tree block. If its not the last key, removal involves a move operation.
This move operation was explicitly done before this commit.

However, at insertion time, there's a move operation before the actual
addition to make room for the new key, which is recorded in the tree mod
log as well. This means, we must drop the move operation when rewinding the
add operation, because the next operation we'll be rewinding will be the
corresponding MOD_LOG_MOVE_KEYS operation.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:40 +02:00
Jan Schmidt 155725c9c0 Btrfs: leave critical region in btrfs_find_all_roots as soon as possible
When delayed refs exist, btrfs_find_all_roots used to hold the delayed ref
mutex way longer than actually required. We ought to drop it immediately
after we're done collecting all the delayed refs.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:39 +02:00
Jan Schmidt c3e0696523 Btrfs: always put insert_ptr modifications into the tree mod log
Several callers of insert_ptr set the tree_mod_log parameter to 0 to avoid
addition to the tree mod log. In fact, we need all of those operations. This
commit simply removes the additional parameter and makes addition to the
tree mod log unconditional.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:39 +02:00
Jan Schmidt 28da9fb446 Btrfs: fix tree mod log for root replacements at leaf level
For the tree mod log, we don't log any operations at leaf level. If the root
is at the leaf level (i.e. the tree consists only of the root), then
__tree_mod_log_oldest_root will find a ROOT_REPLACE operation in the log
(because we always log that one no matter which level), but no other
operations.

With this patch __tree_mod_log_oldest_root exits cleanly instead of
BUGging in this situation. get_old_root checks if its really a root at leaf
level in case we don't have any operations and WARNs if this assumption
breaks.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:38 +02:00
Jan Schmidt 9345457f4a Btrfs: support root level changes in __resolve_indirect_ref
With the tree mod log, we can have a tree that's two levels high, but
btrfs_search_old_slot may still return a path with the tree root at level
one instead. __resolve_indirect_ref must care for this and accept parents in
a lower level than expected.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:38 +02:00
Jan Schmidt 8ca78f3eda Btrfs: avoid waiting for delayed refs when we must not
We track two conditions to decide if we should sleep while waiting for more
delayed refs, the number of delayed refs (num_refs) and the first entry in
the list of blockers (first_seq).

When we suspect staleness, we save num_refs and do one more cycle. If
nothing changes, we then save first_seq for later comparison and do
wait_event. We ought to save first_seq the very same moment we're saving
num_refs. Otherwise we cannot be sure that nothing has changed and we might
start waiting when we shouldn't, which could lead to starvation.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-27 16:34:35 +02:00
Linus Torvalds 8874e812fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This is a small pull with btrfs fixes.  The biggest of the bunch is
  another fix for the new backref walking code.

  We're still hammering out one btrfs dio vs buffered reads problem, but
  that one will have to wait for the next rc."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: delay iput with async extents
  Btrfs: add a missing spin_lock
  Btrfs: don't assume to be on the correct extent in add_all_parents
  Btrfs: introduce btrfs_next_old_item
2012-06-21 13:41:07 -07:00
Josef Bacik cb77fcd885 Btrfs: delay iput with async extents
There is some concern that these iput()'s could be the final iputs and could
induce lockups on people waiting on writeback.  This would happen in the
rare case that we don't create ordered extents because of an error, but it
is theoretically possible and we already have a mechanism to deal with this
so just make them delayed iputs to negate any worry.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-21 07:19:36 -04:00
Josef Bacik e18fca7342 Btrfs: add a missing spin_lock
When fixing up the locking in the delayed ref destruction work I accidently
broke the locking myself ;(.  Add back a spin_lock that should be there and
we are now all set.  Thanks,
Btrfs: add a missing spin_lock

When fixing up the locking in the delayed ref destruction work I accidently
broke the locking myself ;(.  Add back a spin_lock that should be there and
we are now all set.  Thanks,

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-21 07:19:35 -04:00
Alexander Block 69bca40d41 Btrfs: don't assume to be on the correct extent in add_all_parents
add_all_parents did assume that path is already at a correct extent data
item, which may not be true in case of data extents that were partly
rewritten and splitted.

We need to check if we're on a matching extent for every item and only
for the ones after the first. The loop is changed to do this now.

This patch also fixes a bug introduced with commit 3b127fd8 "Btrfs:
remove obsolete btrfs_next_leaf call from __resolve_indirect_ref".
The removal of next_leaf did sometimes result in slot==nritems when
the above described case happens, and thus resulting in invalid values
(e.g. wanted_obejctid) in add_all_parents (leading to missed backrefs
or even crashes).

Signed-off-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-21 07:19:34 -04:00
Alexander Block 1c8f52a5e9 Btrfs: introduce btrfs_next_old_item
We introduce btrfs_next_old_item that uses btrfs_next_old_leaf instead
of btrfs_next_leaf.

btrfs_next_item is also changed to simply call btrfs_next_old_item with
time_seq being 0.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-21 07:19:34 -04:00
Linus Torvalds d865983292 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs compile warning fixes from Chris Mason.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: cast devid to unsigned long long for printk %llu
  Btrfs: init old_generation in get_old_root
2012-06-16 17:01:41 -07:00
Chris Mason a8c4a33b98 Btrfs: cast devid to unsigned long long for printk %llu
Avoid warning in 32 bit machines

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 20:07:17 -04:00
Chris Mason 4325edd078 Btrfs: init old_generation in get_old_root
gcc was giving an uninit variable warning here.  Strictly
speaking we don't need to init it, but this will make things
much less error prone.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 20:06:54 -04:00
Linus Torvalds 718f58ad61 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs update from Chris Mason:
 "The dates look like I had to rebase this morning because there was a
  compiler warning for a printk arg that I had missed earlier.

  These are all fixes, including one to prevent using stale pointers for
  device names, and lots of fixes around transaction abort cleanups
  (Josef, Liu Bo).

  Jan Schmidt also sent in a number of fixes for the new reference
  number tracking code.

  Liu Bo beat me to updating the MAINTAINERS file.  Since he thought to
  also fix the git url, I kept his commit."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
  Btrfs: update MAINTAINERS info for BTRFS FILE SYSTEM
  Btrfs: destroy the items of the delayed inodes in error handling routine
  Btrfs: make sure that we've made everything in pinned tree clean
  Btrfs: avoid memory leak of extent state in error handling routine
  Btrfs: do not resize a seeding device
  Btrfs: fix missing inherited flag in rename
  Btrfs: fix incompat flags setting
  Btrfs: fix defrag regression
  Btrfs: call filemap_fdatawrite twice for compression
  Btrfs: keep inode pinned when compressing writes
  Btrfs: implement ->show_devname
  Btrfs: use rcu to protect device->name
  Btrfs: unlock everything properly in the error case for nocow
  Btrfs: fix btrfs_destroy_marked_extents
  Btrfs: abort the transaction if the commit fails
  Btrfs: wake up transaction waiters when aborting a transaction
  Btrfs: fix locking in btrfs_destroy_delayed_refs
  Btrfs: pass locked_page into extent_clear_unlock_delalloc if theres an error
  Btrfs: fix race in tree mod log addition
  Btrfs: add btrfs_next_old_leaf
  ...
2012-06-15 16:04:37 -07:00
Miao Xie 67cde3448d Btrfs: destroy the items of the delayed inodes in error handling routine
the items of the delayed inodes were forgotten to be freed, this patch
fixes it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 11:42:28 -04:00
Liu Bo ed0eaa1498 Btrfs: make sure that we've made everything in pinned tree clean
Since we have two trees for recording pinned extents, we need to go through
both of them to make sure that we've done everything clean.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 11:42:27 -04:00
Liu Bo 6e841e32b1 Btrfs: avoid memory leak of extent state in error handling routine
We've forgotten to clear extent states in pinned tree, which will results in
space counter mismatch and memory leak:

WARNING: at fs/btrfs/extent-tree.c:7537 btrfs_free_block_groups+0x1f3/0x2e0 [btrfs]()
...
space_info 2 has 8380416 free, is not full
space_info total=12582912, used=4096, pinned=4096, reserved=0, may_use=0, readonly=4194304
btrfs state leak: start 29364224 end 29376511 state 1 in tree ffff880075f20090 refs 1
...

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 11:42:27 -04:00
Liu Bo 4e42ae1bdc Btrfs: do not resize a seeding device
Seeding devices are not supposed to change any more.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 11:42:26 -04:00
Liu Bo bc1782374b Btrfs: fix missing inherited flag in rename
When we move a file into a directory with compression flag, we need to
inherite BTRFS_INODE_COMPRESS and clear BTRFS_INODE_NOCOMPRESS as well.
But if we move a file into a directory without compression flag, we need
to clear both of them.

It is the way how our setflags deals with compression flag, so keep
the same behaviour here.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-15 11:33:30 -04:00
Chris Mason acbcabd2de Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus 2012-06-15 11:33:16 -04:00
Li Zefan 69e380d176 Btrfs: fix incompat flags setting
It's a bug, but it happens to work, as BTRFS_COMPRESS_LZO == 2, which
has only one bit set.

Signed-off-by: Li Zefan <lizefan@huawei.com>
2012-06-14 21:30:57 -04:00
Li Zefan 6c282eb40e Btrfs: fix defrag regression
If a file has 3 small extents:

| ext1 | ext2 | ext3 |

Running "btrfs fi defrag" will only defrag the last two extents, if those
extent mappings hasn't been read into memory from disk.

This bug was introduced by commit 17ce6ef8d7
("Btrfs: add a check to decide if we should defrag the range")

The cause is, that commit looked into previous and next extents using
lookup_extent_mapping() only.

While at it, remove the code that checks the previous extent, since
it's sufficient to check the next extent.

Signed-off-by: Li Zefan <lizefan@huawei.com>
2012-06-14 21:30:55 -04:00
Josef Bacik 7ddf5a42d3 Btrfs: call filemap_fdatawrite twice for compression
I removed this in an earlier commit and I was wrong.  Because compression
can return from filemap_fdatawrite() without having actually set any of it's
pages as writeback() it can make filemap_fdatawait() do essentially nothing,
and then we won't find any ordered extents because they may not have been
created yet.  So not only does this make fsync() completely useless, but it
will also screw up if you truncate on a non-page aligned offset since we
zero out the end and then wait on ordered extents and then call drop caches.
We can drop the cache before the io completes and then we try to unpin the
extent we just wrote we won't find it and everything goes sideways.  So fix
this by putting it back and put a giant comment there to keep me from trying
to remove it in the future.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:30:54 -04:00
Josef Bacik 8180ef8894 Btrfs: keep inode pinned when compressing writes
A user reported lots of problems using compression on the new code and it
turns out part of the problem was that igrab() was failing when we added a
new ordered extent.  This is because when writing out an inode under
compression we immediately return without actually doing anything to the
pages, and then in another thread at some point down the line actually do
the ordered dance.  The problem is between the point that we start writeback
and we actually add the ordered extent we could be trying to reclaim the
inode, which makes igrab() return NULL.  So we need to do an igrab() when we
create the async extent and then drop it when we are done with it.  This
makes sure we stay pinned in memory until the ordered extent can get a
reference on it and we are good to go.  With this patch we no longer panic
in btrfs_finish_ordered_io().  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:30:53 -04:00
Josef Bacik 9c5085c147 Btrfs: implement ->show_devname
Because btrfs can remove the device that was mounted we need to have a
->show_devname so that in this case we can print out some other device in
the file system to /proc/mount.  So if there are multiple devices in a btrfs
file system we will just print the device with the lowest devid that we can
find.  This will make everything consistent and deal with device removal
properly.  The drawback is if you mount with a device that is higher than
the lowest devicd it won't show up as the mounted device in /proc/mounts,
but this is a small price to pay. This was inspired by Miao Xie's patch.
Thanks,

Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:30:37 -04:00
Josef Bacik 606686eeac Btrfs: use rcu to protect device->name
Al pointed out that we can just toss out the old name on a device and add a
new one arbitrarily, so anybody who uses device->name in printk could
possibly use free'd memory.  Instead of adding locking around all of this he
suggested doing it with RCU, so I've introduced a struct rcu_string that
does just that and have gone through and protected all accesses to
device->name that aren't under the uuid_mutex with rcu_read_lock().  This
protects us and I will use it for dealing with removing the device that we
used to mount the file system in a later patch.  Thanks,

Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:16 -04:00
Josef Bacik 17ca04aff7 Btrfs: unlock everything properly in the error case for nocow
I was getting hung on umount when a transaction was aborted because a range
of one of the free space inodes was still locked.  This is because the nocow
stuff doesn't unlock anything on error.  This fixed the problem and I
verified that is what was happening.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:15 -04:00
Josef Bacik ee670f0af3 Btrfs: fix btrfs_destroy_marked_extents
So we're forcing the eb's to have their ref count set to 1 so invalidatepage
works but this breaks lots of things, for example root nodes, and is just
plain wrong, we don't need to just evict all of this stuff.  Also drop the
invalidatepage altogether and add a page_cache_release().  With this patch
we no longer hang when trying to access the root nodes after an aborted
transaction and we no longer leak memory.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:14 -04:00
Josef Bacik 7b8b92af58 Btrfs: abort the transaction if the commit fails
If a transaction commit fails we don't abort it so we don't set an error on
the file system.  This patch fixes that by actually calling the abort stuff
and then adding a check for a fs error in the transaction start stuff to
make sure it is caught properly.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:13 -04:00
Josef Bacik d7096fc3ef Btrfs: wake up transaction waiters when aborting a transaction
I was getting lots of hung tasks and a NULL pointer dereference because we
are not cleaning up the transaction properly when it aborts.  First we need
to reset the running_transaction to NULL so we don't get a bad dereference
for any start_transaction callers after this.  Also we cannot rely on
waitqueue_active() since it's just a list_empty(), so just call wake_up()
directly since that will do the barrier for us and such.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:12 -04:00
Josef Bacik b939d1ab76 Btrfs: fix locking in btrfs_destroy_delayed_refs
The transaction abort stuff was throwing warnings from the list debugging
code because we do a list_del_init outside of the delayed_refs spin lock.
The delayed refs locking makes baby Jesus cry so it's not hard to get wrong,
but we need to take the ref head mutex to make sure it's not being processed
currently, and so if it is we need to drop the spin lock and then take and
drop the mutex and do the search again.  If we can take the mutex then we
can safely remove the head from the list and carry on.  Now when the
transaction aborts I don't get the list debugging warnings.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:11 -04:00
Josef Bacik beb42dd793 Btrfs: pass locked_page into extent_clear_unlock_delalloc if theres an error
While doing my enospc work I got a transaction abortion that resulted in a
panic when we tried to unlock_page() an already unlocked page.  This is
because we aren't calling extent_clear_unlock_delalloc with the locked page
so it was unlocking all the pages in the range.  This is wrong since
__extent_writepage expects to have the page locked still unless we return
*page_started as 1.  This should keep us from panicing.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-14 21:29:09 -04:00