Commit Graph

336466 Commits

Author SHA1 Message Date
Eric Sandeen
5a01604783 btrfs: remove unused fs_info from btrfs_decode_error()
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:17 -05:00
Eric Sandeen
d1d3cd27a3 btrfs: list_entry can't return NULL
No need to test the result, we can't get a
null pointer from list_entry()

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:15 -05:00
Eric Sandeen
b4c6f7b75c btrfs: remove unused fd in btrfs_ioctl_send()
All we do is set it to NULL and test it :)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:14 -05:00
Josef Bacik
96f1bb5777 Btrfs: do not overcommit if we don't have enough space for global rsv
Because of how little we allocate chunks now we can get really tight on
metadata space before we will allocate a new chunk.  This resulted in being
unable to add device extents when allocating a new metadata chunk as we did
not have enough space.  This is because we were allowed to overcommit too
much metadata without actually making sure we had enough space to make
allocations.  The idea behind overcommit is that we are allowed to say "sure
you can have that reservation" when most of the free space is occupied by
reservations, not actual allocations.  But in this case where a majority of
the total space is in use by actual allocations we can screw ourselves by
not being able to make real allocations when it matters.  So make sure we
have enough real space for our global reserve, and if not then don't allow
overcommitting.  Thanks,

Reported-and-tested-by: Jim Schutt <jaschut@sandia.gov>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:13 -05:00
Josef Bacik
0f5d42b287 Btrfs: remove extent mapping if we fail to add chunk
I got a double free error when unmounting a file system that failed to add a
chunk during its operation.  This is because we will kfree the mapping that
we created but leave the extent_map in the em_tree for chunks.  So to fix
this just remove the extent_map when we error out so we don't run into this
problem.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:11 -05:00
Josef Bacik
0448748849 Btrfs: fix chunk allocation error handling
If we error out allocating a dev extent we will have already created the
block group and such which will cause problems since the allocator may have
tried to allocate out of the block group that no longer exists.  This will
cause BUG_ON()'s in the bio submission path.  This also makes a failure to
allocate a dev extent a non-abort error, we will just clean up the dev
extents we did allocate and exit.  Now if we fail to delete the dev extents
we will abort since we can't have half of the dev extents hanging around,
but this will make us much less likely to abort.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:10 -05:00
Miao Xie
87533c4751 Btrfs: use bit operation for ->fs_state
There is no lock to protect fs_info->fs_state, it will introduce
some problems, such as the value may be covered by the other task
when several tasks modify it. For example:
	Task0 - CPU0		Task1 - CPU1
	mov %fs_state rax
	or $0x1 rax
				mov %fs_state rax
				or $0x2 rax
	mov rax %fs_state
				mov rax %fs_state
The expected value is 3, but in fact, it is 2.

Though this problem doesn't happen now (because there is only one
flag currently), the code is error prone, if we add other flags,
the above problem will happen to a certainty.

Now we use bit operation for it to fix the above problem.
In this way, we can make the code more robust and be easy to
add new flags.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:09 -05:00
Miao Xie
de98ced9e7 Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits
There is no lock to protect
  fs_info->avail_{data, metadata, system}_alloc_bits,
it may introduce some problem, such as the wrong profile
information, so we add a seqlock to protect them.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:08 -05:00
Miao Xie
df0af1a57f Btrfs: use the inode own lock to protect its delalloc_bytes
We need not use a global lock to protect the delalloc_bytes of the
inode, just use its own lock. In this way, we can reduce the lock
contention and ->delalloc_lock will just protect delalloc inode
list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:06 -05:00
Miao Xie
963d678b0f Btrfs: use percpu counter for fs_info->delalloc_bytes
fs_info->delalloc_bytes is accessed very frequently, so use percpu
counter instead of the u64 variant for it to reduce the lock
contention.

This patch also fixed the problem that we access the variant
without the lock protection.At worst, we would not flush the
delalloc inodes, and just return ENOSPC error when we still have
some free space in the fs.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:05 -05:00
Miao Xie
e2d845211e Btrfs: use percpu counter for dirty metadata count
->dirty_metadata_bytes is accessed very frequently, so use percpu
counter instead of the u64 variant to reduce the contention of
the lock.

This patch also fixed the problem that we access it without
lock protection in __btrfs_btree_balance_dirty(), which may
cause we skip the dirty pages flush.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:04 -05:00
Miao Xie
c018daecea Btrfs: protect fs_info->alloc_start
fs_info->alloc_start is a 64bits variant, can be accessed by
multi-task, but it is not protected strictly, it can be changed
while we are accessing it. On 32bit machine, we will get wrong
value because we access it by two instructions.(In fact, it is
also possible that the same problem happens on the 64bit machine,
because the compiler may split the 64bit operation into two 32bit
operation.)

For example:
Assuming -> alloc_start is 0x0000 0000 0001 0000 at the beginning,
then we remount and set ->alloc_start to 0x0000 0100 0000 0000.
	Task0 			Task1
				load high 32 bits
	set high 32 bits
	set low 32 bits
				load low 32 bits

Task1 will get 0.

This patch fixes this problem by using two locks to protect it
	fs_info->chunk_mutex
	sb->s_umount
On the read side, we just need get one of these two locks, and on
the write side, we must lock all of them.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:02 -05:00
Miao Xie
8c6a3ee6db Btrfs: add a comment for fs_info->max_inline
Though ->max_inline is a 64bit variant, and may be accessed by
multi-task, but it is just suggestive number, so we needn't add
anything to protect fs_info->max_inline, just add a comment to
explain wny we don't use a lock to protect it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:01 -05:00
Filipe Brandenburger
55e301fd57 Btrfs: move fs/btrfs/ioctl.h to include/uapi/linux/btrfs.h
The header file will then be installed under /usr/include/linux so that
userspace applications can refer to Btrfs ioctls by name and use the same
structs used internally in the kernel.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:28 -05:00
Kusanagi Kouichi
82b22ac8f6 Btrfs: Check CAP_DAC_READ_SEARCH for BTRFS_IOC_INO_PATHS
CAP_DAC_READ_SEARCH overrides read and search permission check on
file and directory. It seems fit for BTRFS_IOC_INO_PATHS.

Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:27 -05:00
Josef Bacik
fe5fafbebd Revert "Btrfs: fix permissions of empty files not affected by umask"
This reverts commit 2794ed013b.

Wasn't supposed to get used in btrfs_mknod, it was supposed to be in
btrfs_create, which was done in commit
9185aa587b.

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:26 -05:00
Miao Xie
5b947f1ba9 Btrfs: don't traverse the ordered operation list repeatedly
btrfs_run_ordered_operations() needn't traverse the ordered operation list
repeatedly, it is because the transaction commiter will invoke it again when
there is no other writer in this transaction, it can ensure that no one can
add new objects into the ordered operation list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:24 -05:00
Miao Xie
63607cc86a Btrfs: traverse and flush the delalloc inodes once
btrfs_start_delalloc_inodes() needn't traverse and flush the delalloc inodes
repeatedly. It is because we can regard the data that the users write after
we start delalloc inodes flush as the one which is after the delalloc inodes
flush is done, and we can flush it next time.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:23 -05:00
Miao Xie
eebc608406 Btrfs: check the return value of btrfs_run_ordered_operations()
We forget to check the return value of btrfs_run_ordered_operations() when
flushing all the pending stuffs, fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:22 -05:00
Miao Xie
3edb2a68cb Btrfs: check the return value of btrfs_start_delalloc_inodes()
We forget to check the return value of btrfs_start_delalloc_inodes(), fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:21 -05:00
Miao Xie
e6ec716f0d Btrfs: make raid attr array more readable
The current code of raid attr arry is hard to understand and it is easy to
introduce some problem if we modify the array. So I changed it and made it
more readable.

Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:19 -05:00
Liu Bo
a1897fddd2 Btrfs: record first logical byte in memory
This'd save us a rbtree search which may become expensive in large filesystem.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:18 -05:00
Liu Bo
39f9d028c9 Btrfs: save us a read_lock
This does not change the logic of code, but can save us a read_lock.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:17 -05:00
Liu Bo
51fab69347 Btrfs: use token to avoid times mapping extent buffer
The API in tree log code has done sort of changes, and it proves that
we can benifit from using token, so do the same thing here.

function_graph tracer's timer shows that it costs nearly half time
of before(39.788us -> 22.391us).

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:15 -05:00
Liu Bo
dcfac4156f Btrfs: kill unused argument of btrfs_pin_extent_for_log_replay
Argument 'trans' is not used any more.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:14 -05:00
Liu Bo
c53d613e52 Btrfs: kill unused argument of update_block_group
Argument 'trans' is not used any more.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:13 -05:00
Liu Bo
f6373bf3dc Btrfs: kill unused arguments of cache_block_group
Argument 'trans' and 'root' are not used any more.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:11 -05:00
Liu Bo
17b85495cf Btrfs: remove deprecated comments
commit d53ba47484
(Btrfs: use commit root when loading free space cache) has remove
the deadlock check, and the related comments can be removed as well.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:10 -05:00
Josef Bacik
c6b305a89b Btrfs: don't re-enter when allocating a chunk
If we start running low on metadata space we will try to allocate a chunk,
which could then try to allocate a chunk to add the device entry.  The thing
is we allocate a chunk before we try really hard to make the allocation, so
we should be able to find space for the device entry.  Add a flag to the
trans handle so we know we're currently allocating a chunk so we can just
bail out if we try to allocate another chunk.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:09 -05:00
Josef Bacik
2ab28f322f Btrfs: wait on ordered extents at the last possible moment
Since we don't actually copy the extent information from the source tree in
the fast case we don't need to wait for ordered io to be completed in order
to fsync, we just need to wait for the io to be completed.  So when we're
logging our file just attach all of the ordered extents to the log, and then
when the log syncs just wait for IO_DONE on the ordered extents and then
write the super.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:37:04 -05:00
Miao Xie
dfd79829b7 Btrfs: fix trivial error in btrfs_ioctl_resize()
This patch fixes the following problem:
- improper return value
- unnecessary read-only check

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:44 -05:00
Miao Xie
4eee4fa4f8 Btrfs: use wrapper page_offset
Use wrapper page_offset to get byte-offset into filesystem object for page.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:43 -05:00
Miao Xie
da633a4217 Btrfs: flush all dirty inodes if writeback can not start
We may try to flush some dirty pages when there is no enough space to reserve.
But it is possible that this operation fails, in order to get enough space to
reserve successfully, we will sync all the delalloc file. This operation is
safe, we needn't worry about the case that the filesystem goes from r/w to r/o.
because the filesystem should guarantee all the dirty pages have been written
into the disk after it becomes readonly, so the sync operation will do nothing
if the filesystem is already readonly. Though it may waste lots of time,
as a corner case, we needn't care.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:42 -05:00
Miao Xie
093486c453 Btrfs: make delayed ref lock logic more readable
Locking and unlocking delayed ref mutex are in the different functions,
and the name of lock functions is not uniform, so the readability is not
so good, this patch optimizes the lock logic and makes it more readable.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:41 -05:00
Miao Xie
0e8c36a9fd Btrfs: fix lots of orphan inodes when the space is not enough
We're running into having 50-100 orphans left over with xfstests 83
because of ENOSPC when trying to start the transaction for the inode update.
But in fact, it makes no sense in updating the inode for the new size while
we're deleting the stupid thing. This patch fixes this problem.

Reported-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:39 -05:00
Miao Xie
4ea41ce07d Btrfs: cleanup similar code in delayed inode
The delayed item commit code in several functions is similar, so
cleanup it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 09:36:38 -05:00
Miao Xie
7892b5afe4 Btrfs: use common work instead of delayed work
Since we do not want to delay the async transaction commit, we should
use common work, not delayed work.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2013-02-20 09:36:37 -05:00
Miao Xie
7b5a1c5310 Btrfs: cleanup unnecessary clear when freeing a transaction or a trans handle
We clear the transaction object and the trans handle when they are about to be
freed, it is unnecessary, cleanup it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2013-02-20 09:36:35 -05:00
Miao Xie
78a6184a3f Btrfs: use slabs for delayed reference allocation
The delayed reference allocation is in the fast path of the IO, so use slabs
to improve the speed of the allocation.

And besides that, it can do check for leaked objects when the module is removed.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2013-02-20 09:36:34 -05:00
David Sterba
6f60cbd3ae btrfs: access superblock via pagecache in scan_one_device
btrfs_scan_one_device is calling set_blocksize() which can race
with a concurrent process making dirty page cache pages.  It can end up
dropping dirty page cache pages on the floor, which isn't very nice when
someone is just running btrfs dev scan to find filesystems on the
box.

Now that udev is registering btrfs devices as it discovers them, we can
actually end up racing with our own mkfs program too.  When this
happens, we drop some of the important blocks written by mkfs.

This commit changes scan_one_device to read the super out of the page
cache instead of trying to use bread.  This way we don't have to care
about the blocksize of the device.

This also drops the invalidate_bdev() call.  It wasn't very polite to
invalidate during the scan either.  mkfs is putting the super into the
page cache, there's no reason to invalidate at this point.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-15 16:57:47 -05:00
Arne Jansen
2a745b14bc Btrfs: fix crash in log replay with qgroups enabled
When replaying a log tree with qgroups enabled, tree_mod_log_rewind does a
sanity-check of the number of items against the maximum possible number.
It calculates that number with the nodesize of fs_root. Unfortunately
fs_root is not yet set at this stage. So instead use the nodesize from
tree_root, which is already initialized.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-14 20:47:41 -05:00
Chris Mason
1a65e24b0b Btrfs: move d_instantiate outside the transaction during mksubvol
Dave Sterba triggered a lockdep complaint about lock ordering
between the sb_internal lock and the cleaner semaphore.

btrfs_lookup_dentry() checks for orphans if we're looking up
the inode for a subvolume, and subvolume creation is triggering
the lookup with a transaction running.

This commit moves the d_instantiate after the transaction closes.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-06 12:11:10 -05:00
Jan Schmidt
eb6b88d92c Btrfs: fix EDQUOT handling in btrfs_delalloc_reserve_metadata
When btrfs_qgroup_reserve returned a failure, we were missing a counter
operation for BTRFS_I(inode)->outstanding_extents++, leading to warning
messages about outstanding extents and space_info->bytes_may_use != 0.
Additionally, the error handling code didn't take into account that we
dropped the inode lock which might require more cleanup.

Luckily, all the cleanup code we need is already there and can be shared
with reserve_metadata_bytes, which is exactly what this patch does.

Reported-by: Lev Vainblat <lev@zadarastorage.com>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-06 09:24:40 -05:00
Chris Mason
24f8ebe918 Merge git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next.git for-chris into for-linus 2013-02-05 19:24:44 -05:00
Josef Bacik
59fe4f4197 Btrfs: fix possible stale data exposure
We specifically do not update the disk i_size if there are ordered extents
outstanding for any area between the current disk_i_size and our ordered
extent so that we do not expose stale data.  The problem is the check we
have only checks if the ordered extent starts at or after the current
disk_i_size, which doesn't take into account an ordered extent that starts
before the current disk_i_size and ends past the disk_i_size.  Fix this by
checking if the extent ends past the disk_i_size.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:16 -05:00
Josef Bacik
5d1f40202b Btrfs: fix missing i_size update
If we have an ordered extent before the ordered extent we are currently
completing that is after the current disk_i_size we will put our i_size
update into that ordered extent so that we do not expose stale data.  The
problem is that if our disk i_size is updated past the previous ordered
extent we won't update the i_size with the pending i_size update.  So check
the pending i_size update and if its above the current disk i_size we need
to go ahead and try to update.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:14 -05:00
Liu Bo
6f1c36055f Btrfs: fix race between snapshot deletion and getting inode
While running snapshot testscript created by Mitch and David,
the race between autodefrag and snapshot deletion can lead to
corruption of dead_root list so that we can get crash on
btrfs_clean_old_snapshots().

And besides autodefrag, scrub also does the same thing, ie. read
root first and get inode.

Here is the story(take autodefrag as an example):
(1) when we delete a snapshot or subvolume, it will set its root's
refs to zero and do a iput() on its own inode, and if this inode happens
to be the only active in-meory one in root's inode rbtree, it will add
itself to the global dead_roots list for later cleanup.

(2) after (1), the autodefrag thread may read another inode for defrag
and the inode is just in the deleted snapshot/subvolume, but all of these
are without checking if the root is still valid(refs > 0).  So the end up
result is adding the deleted snapshot/subvolume's root to the global
dead_roots list AGAIN.

Fortunately, we already have a srcu lock to avoid the race, ie. subvol_srcu.

So all we need to do is to take the lock to protect 'read root and get inode',
since we synchronize to wait for the rcu grace period before adding something
to the global dead_roots list.

Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:13 -05:00
Miao Xie
843fcf3573 Btrfs: fix missing release of the space/qgroup reservation in start_transaction()
When we fail to start a transaction, we need to release the reserved free space
and qgroup space, fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:11 -05:00
Miao Xie
0a3404dcff Btrfs: fix wrong sync_writers decrement in btrfs_file_aio_write()
If the checks at the beginning of btrfs_file_aio_write() fail, we needn't
decrease ->sync_writers, because we have not increased it. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:10 -05:00
Josef Bacik
222c81dc38 Btrfs: do not merge logged extents if we've removed them from the tree
You can run into this problem where if somebody is fsyncing and writing out
the existing extents you will have removed the extent map from the em tree,
but it's still valid for the current fsync so we go ahead and write it.  The
problem is we unconditionally try to merge it back into the em tree, but if
we've removed it from the em tree that will cause use after free problems.
Fix this to only merge if we are still a part of the tree.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-05 16:09:03 -05:00