Commit Graph

4159 Commits

Author SHA1 Message Date
Linus Torvalds da83fc6e0f 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 two more fixes in my for-linus branch.

  I was hoping to also include a fix for a btrfs deadlock with
  compression enabled, but we're still nailing that one down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: test for valid bdev before kobj removal in btrfs_rm_device
  Btrfs: fix abnormal long waiting in fsync
2014-07-20 20:21:05 -07:00
Eric Sandeen 0bfaa9c5cb btrfs: test for valid bdev before kobj removal in btrfs_rm_device
commit 99994cd btrfs: dev delete should remove sysfs entry
added a btrfs_kobj_rm_device, which dereferences device->bdev...
right after we check whether device->bdev might be NULL.

I don't honestly know if it's possible to have a NULL device->bdev
here, but assuming that it is (given the test), we need to move
the kobject removal to be under that test.

(Coverity spotted this)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-19 11:49:44 -07:00
Liu Bo 98ce2deda2 Btrfs: fix abnormal long waiting in fsync
xfstests generic/127 detected this problem.

With commit 7fc34a62ca, now fsync will only flush
data within the passed range.  This is the cause of the above problem,
-- btrfs's fsync has a stage called 'sync log' which will wait for all the
ordered extents it've recorded to finish.

In xfstests/generic/127, with mixed operations such as truncate, fallocate,
punch hole, and mapwrite, we get some pre-allocated extents, and mapwrite will
mmap, and then msync.  And I find that msync will wait for quite a long time
(about 20s in my case), thanks to ftrace, it turns out that the previous
fallocate calls 'btrfs_wait_ordered_range()' to flush dirty pages, but as the
range of dirty pages may be larger than 'btrfs_wait_ordered_range()' wants,
there can be some ordered extents created but not getting corresponding pages
flushed, then they're left in memory until we fsync which runs into the
stage 'sync log', and fsync will just wait for the system writeback thread
to flush those pages and get ordered extents finished, so the latency is
inevitable.

This adds a flush similar to btrfs_start_ordered_extent() in
btrfs_wait_logged_extents() to fix that.

Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-19 11:49:44 -07:00
Linus Torvalds b82207b8e8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "We've queued up a few fixes in my for-linus branch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix crash when starting transaction
  Btrfs: fix btrfs_print_leaf for skinny metadata
  Btrfs: fix race of using total_bytes_pinned
  btrfs: use E2BIG instead of EIO if compression does not help
  btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
  Btrfs: fix use-after-free when cloning a trailing file hole
  btrfs: fix null pointer dereference in btrfs_show_devname when name is null
  btrfs: fix null pointer dereference in clone_fs_devices when name is null
  btrfs: fix nossd and ssd_spread mount option regression
  Btrfs: fix race between balance recovery and root deletion
  Btrfs: atomically set inode->i_flags in btrfs_update_iflags
  btrfs: only unlock block in verify_parent_transid if we locked it
  Btrfs: assert send doesn't attempt to start transactions
  btrfs compression: reuse recently used workspace
  Btrfs: fix crash when mounting raid5 btrfs with missing disks
  btrfs: create sprout should rename fsid on the sysfs as well
  btrfs: dev replace should replace the sysfs entry
  btrfs: dev add should add its sysfs entry
  btrfs: dev delete should remove sysfs entry
  btrfs: rename add_device_membership to btrfs_kobj_add_device
2014-07-04 08:53:53 -07:00
Filipe Manana abdd2e80a5 Btrfs: fix crash when starting transaction
Often when starting a transaction we commit the currently running transaction,
which can end up writing block group caches when the current process has its
journal_info set to NULL (and not to a transaction). This makes our assertion
at btrfs_check_data_free_space() (current_journal != NULL) fail, resulting
in a crash/hang. Therefore fix it by setting journal_info.

Two different traces of this issue follow below.

1)

    [51502.241936] BTRFS: assertion failed: current->journal_info, file: fs/btrfs/extent-tree.c, line: 3670
    [51502.242213] ------------[ cut here ]------------
    [51502.242493] kernel BUG at fs/btrfs/ctree.h:3964!
    [51502.242669] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
    (...)
    [51502.244010] Call Trace:
    [51502.244010]  [<ffffffffa02bc025>] btrfs_check_data_free_space+0x395/0x3a0 [btrfs]
    [51502.244010]  [<ffffffffa02c3bdc>] btrfs_write_dirty_block_groups+0x4ac/0x640 [btrfs]
    [51502.244010]  [<ffffffffa0357a6a>] commit_cowonly_roots+0x164/0x226 [btrfs]
    [51502.244010]  [<ffffffffa02d53cd>] btrfs_commit_transaction+0x4ed/0xab0 [btrfs]
    [51502.244010]  [<ffffffff8168ec7b>] ? _raw_spin_unlock+0x2b/0x40
    [51502.244010]  [<ffffffffa02d6259>] start_transaction+0x459/0x620 [btrfs]
    [51502.244010]  [<ffffffffa02d67ab>] btrfs_start_transaction+0x1b/0x20 [btrfs]
    [51502.244010]  [<ffffffffa02d73e1>] __unlink_start_trans+0x31/0xe0 [btrfs]
    [51502.244010]  [<ffffffffa02dea67>] btrfs_unlink+0x37/0xc0 [btrfs]
    [51502.244010]  [<ffffffff811bb054>] ? do_unlinkat+0x114/0x2a0
    [51502.244010]  [<ffffffff811baebc>] vfs_unlink+0xcc/0x150
    [51502.244010]  [<ffffffff811bb1a0>] do_unlinkat+0x260/0x2a0
    [51502.244010]  [<ffffffff811a9ef4>] ? filp_close+0x64/0x90
    [51502.244010]  [<ffffffff810aaea6>] ? trace_hardirqs_on_caller+0x16/0x1e0
    [51502.244010]  [<ffffffff81349cab>] ? trace_hardirqs_on_thunk+0x3a/0x3f
    [51502.244010]  [<ffffffff811be9eb>] SyS_unlinkat+0x1b/0x40
    [51502.244010]  [<ffffffff81698452>] system_call_fastpath+0x16/0x1b
    [51502.244010] Code: 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 89 f1 48 c7 c2 71 13 36 a0 48 89 fe 31 c0 48 c7 c7 b8 43 36 a0 48 89 e5 e8 5d b0 32 e1 <0f> 0b 0f 1f 44 00 00 55 b9 11 00 00 00 48 89 e5 41 55 49 89 f5
    [51502.244010] RIP  [<ffffffffa03575da>] assfail.constprop.88+0x1e/0x20 [btrfs]

2)

    [25405.097230] BTRFS: assertion failed: current->journal_info, file: fs/btrfs/extent-tree.c, line: 3670
    [25405.097488] ------------[ cut here ]------------
    [25405.097767] kernel BUG at fs/btrfs/ctree.h:3964!
    [25405.097940] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
    (...)
    [25405.100008] Call Trace:
    [25405.100008]  [<ffffffffa02bc025>] btrfs_check_data_free_space+0x395/0x3a0 [btrfs]
    [25405.100008]  [<ffffffffa02c3bdc>] btrfs_write_dirty_block_groups+0x4ac/0x640 [btrfs]
    [25405.100008]  [<ffffffffa035755a>] commit_cowonly_roots+0x164/0x226 [btrfs]
    [25405.100008]  [<ffffffffa02d53cd>] btrfs_commit_transaction+0x4ed/0xab0 [btrfs]
    [25405.100008]  [<ffffffff8109c170>] ? bit_waitqueue+0xc0/0xc0
    [25405.100008]  [<ffffffffa02d6259>] start_transaction+0x459/0x620 [btrfs]
    [25405.100008]  [<ffffffffa02d67ab>] btrfs_start_transaction+0x1b/0x20 [btrfs]
    [25405.100008]  [<ffffffffa02e3407>] btrfs_create+0x47/0x210 [btrfs]
    [25405.100008]  [<ffffffffa02d74cc>] ? btrfs_permission+0x3c/0x80 [btrfs]
    [25405.100008]  [<ffffffff811bc63b>] vfs_create+0x9b/0x130
    [25405.100008]  [<ffffffff811bcf19>] do_last+0x849/0xe20
    [25405.100008]  [<ffffffff811b9409>] ? link_path_walk+0x79/0x820
    [25405.100008]  [<ffffffff811bd5b5>] path_openat+0xc5/0x690
    [25405.100008]  [<ffffffff810ab07d>] ? trace_hardirqs_on+0xd/0x10
    [25405.100008]  [<ffffffff811cdcd2>] ? __alloc_fd+0x32/0x1d0
    [25405.100008]  [<ffffffff811be2a3>] do_filp_open+0x43/0xa0
    [25405.100008]  [<ffffffff811cddf1>] ? __alloc_fd+0x151/0x1d0
    [25405.100008]  [<ffffffff811abcfc>] do_sys_open+0x13c/0x230
    [25405.100008]  [<ffffffff810aaea6>] ? trace_hardirqs_on_caller+0x16/0x1e0
    [25405.100008]  [<ffffffff811abe12>] SyS_open+0x22/0x30
    [25405.100008]  [<ffffffff81698452>] system_call_fastpath+0x16/0x1b
    [25405.100008] Code: 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 89 f1 48 c7 c2 51 13 36 a0 48 89 fe 31 c0 48 c7 c7 d0 43 36 a0 48 89 e5 e8 6d b5 32 e1 <0f> 0b 0f 1f 44 00 00 55 b9 11 00 00 00 48 89 e5 41 55 49 89 f5
    [25405.100008] RIP  [<ffffffffa03570ca>] assfail.constprop.88+0x1e/0x20 [btrfs]

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:18 -07:00
Josef Bacik be2c765dff Btrfs: fix btrfs_print_leaf for skinny metadata
We wouldn't actuall print the extent information if we had a skinny metadata
item, this fixes that.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:16 -07:00
Liu Bo d288db5dc0 Btrfs: fix race of using total_bytes_pinned
This percpu counter @total_bytes_pinned is introduced to skip unnecessary
operations of 'commit transaction', it accounts for those space we may free
but are stuck in delayed refs.

And we zero out @space_info->total_bytes_pinned every transaction period so
we have a better idea of how much space we'll actually free up by committing
this transaction.  However, we do the 'zero out' part a little earlier, before
we actually unpin space, so we end up returning ENOSPC when we actually have
free space that's just unpinned from committing transaction.

xfstests/generic/074 complained then.

This fixes it by actually accounting the percpu pinned number when 'unpin',
and since it's protected by space_info->lock, the race is gone now.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:15 -07:00
David Sterba 130d5b415a btrfs: use E2BIG instead of EIO if compression does not help
Return codes got updated in 60e1975acb
(btrfs: return errno instead of -1 from compression)
lzo wrapper returns E2BIG in this case, do the same for zlib.

Signed-off-by: David Sterba <dsterba@suse.cz>
2014-07-03 07:04:13 -07:00
David Sterba 0a4eaea892 btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
Commit fcebe4562d (Btrfs: rework qgroup
accounting) removed the qgroup accounting after delayed refs.

Signed-off-by: David Sterba <dsterba@suse.cz>
2014-07-03 07:04:12 -07:00
Filipe Manana 14f5979633 Btrfs: fix use-after-free when cloning a trailing file hole
The transaction handle was being used after being freed.

Cc: Chris Mason <clm@fb.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:10 -07:00
Anand Jain 0aeb8a6e67 btrfs: fix null pointer dereference in btrfs_show_devname when name is null
dev->name is null but missing flag is not set.
Strictly speaking the missing flag should have been set, but there
are more places where code just checks if name is null. For now this
patch does the same.

stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000064
IP: [<ffffffffa0228908>] btrfs_show_devname+0x58/0xf0 [btrfs]

[<ffffffff81198879>] show_vfsmnt+0x39/0x130
[<ffffffff81178056>] m_show+0x16/0x20
[<ffffffff8117d706>] seq_read+0x296/0x390
[<ffffffff8115aa7d>] vfs_read+0x9d/0x160
[<ffffffff8115b549>] SyS_read+0x49/0x90
[<ffffffff817abe52>] system_call_fastpath+0x16/0x1b

reproducer:
mkfs.btrfs -draid1 -mraid1 /dev/sdg1 /dev/sdg2
btrfstune -S 1 /dev/sdg1
modprobe -r btrfs && modprobe btrfs
mount -o degraded /dev/sdg1 /btrfs
btrfs dev add /dev/sdg3 /btrfs

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:09 -07:00
Anand Jain e755f78086 btrfs: fix null pointer dereference in clone_fs_devices when name is null
when one of the device path is missing btrfs_device name is null. So this
patch will check for that.

stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff812e18c0>] strlen+0x0/0x30
[<ffffffffa01cd92a>] ? clone_fs_devices+0xaa/0x160 [btrfs]
[<ffffffffa01cdcf7>] btrfs_init_new_device+0x317/0xca0 [btrfs]
[<ffffffff81155bca>] ? __kmalloc_track_caller+0x15a/0x1a0
[<ffffffffa01d6473>] btrfs_ioctl+0xaa3/0x2860 [btrfs]
[<ffffffff81132a6c>] ? handle_mm_fault+0x48c/0x9c0
[<ffffffff81192a61>] ? __blkdev_put+0x171/0x180
[<ffffffff817a784c>] ? __do_page_fault+0x4ac/0x590
[<ffffffff81193426>] ? blkdev_put+0x106/0x110
[<ffffffff81179175>] ? mntput+0x35/0x40
[<ffffffff8116d4b0>] do_vfs_ioctl+0x460/0x4a0
[<ffffffff8115c72e>] ? ____fput+0xe/0x10
[<ffffffff81068033>] ? task_work_run+0xb3/0xd0
[<ffffffff8116d547>] SyS_ioctl+0x57/0x90
[<ffffffff817a793e>] ? do_page_fault+0xe/0x10
[<ffffffff817abe52>] system_call_fastpath+0x16/0x1b

reproducer:
mkfs.btrfs -draid1 -mraid1 /dev/sdg1 /dev/sdg2
btrfstune -S 1 /dev/sdg1
modprobe -r btrfs && modprobe btrfs
mount -o degraded /dev/sdg1 /btrfs
btrfs dev add /dev/sdg3 /btrfs

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:07 -07:00
Eric Sandeen 2aa06a35d0 btrfs: fix nossd and ssd_spread mount option regression
The commit

0780253 btrfs: Cleanup the btrfs_parse_options for remount.

broke ssd options quite badly; it stopped making ssd_spread
imply ssd, and it made "nossd" unsettable.

Put things back at least as well as they were before
(though ssd mount option handling is still pretty odd:
# mount -o "nossd,ssd_spread" works?)

Reported-by: Roman Mamedov <rm@romanrm.net>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:06 -07:00
Wang Shilong 5f3164813b Btrfs: fix race between balance recovery and root deletion
Balance recovery is called when RW mounting or remounting from
RO to RW, it is called to finish roots merging.

When doing balance recovery, relocation root's corresponding
fs root(whose root refs is 0) might be destroyed by cleaner
thread, this will make btrfs fail to mount.

Fix this problem by holding @cleaner_mutex when doing balance
recovery.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:04 -07:00
Filipe Manana 3cc7939255 Btrfs: atomically set inode->i_flags in btrfs_update_iflags
This change is based on the corresponding recent change for ext4:

  ext4: atomically set inode->i_flags in ext4_set_inode_flags()

That has the following commit message that applies to btrfs as well:

  "Use cmpxchg() to atomically set i_flags instead of clearing out the
   S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
   EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
   where an immutable file has the immutable flag cleared for a brief
   window of time."

Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE
and BTRFS_INODE_APPEND, respectively.

Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:03:23 -07:00
Josef Bacik 472b909ff6 btrfs: only unlock block in verify_parent_transid if we locked it
This is a regression from my patch a26e8c9f75, we
need to only unlock the block if we were the one who locked it.  Otherwise this
will trip BUG_ON()'s in locking.c  Thanks,

cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:47 -07:00
Filipe Manana 46c4e71e9b Btrfs: assert send doesn't attempt to start transactions
When starting a transaction just assert that current->journal_info
doesn't contain a send transaction stub, since send isn't supposed
to start transactions and when it finishes (either successfully or
not) it's supposed to set current->journal_info to NULL.

This is motivated by the change titled:

    Btrfs: fix crash when starting transaction

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:46 -07:00
Sergey Senozhatsky c39aa7056f btrfs compression: reuse recently used workspace
Add compression `workspace' in free_workspace() to
`idle_workspace' list head, instead of tail. So we have
better chances to reuse most recently used `workspace'.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:46 -07:00
Liu Bo 5588383ece Btrfs: fix crash when mounting raid5 btrfs with missing disks
The reproducer is

$ mkfs.btrfs D1 D2 D3 -mraid5
$ mkfs.ext4 D2 && mkfs.ext4 D3
$ mount D1 /btrfs -odegraded

-------------------

[   87.672992] ------------[ cut here ]------------
[   87.673845] kernel BUG at fs/btrfs/raid56.c:1828!
...
[   87.673845] RIP: 0010:[<ffffffff813efc7e>]  [<ffffffff813efc7e>] __raid_recover_end_io+0x4ae/0x4d0
...
[   87.673845] Call Trace:
[   87.673845]  [<ffffffff8116bbc6>] ? mempool_free+0x36/0xa0
[   87.673845]  [<ffffffff813f0255>] raid_recover_end_io+0x75/0xa0
[   87.673845]  [<ffffffff81447c5b>] bio_endio+0x5b/0xa0
[   87.673845]  [<ffffffff81447cb2>] bio_endio_nodec+0x12/0x20
[   87.673845]  [<ffffffff81374621>] end_workqueue_fn+0x41/0x50
[   87.673845]  [<ffffffff813ad2aa>] normal_work_helper+0xca/0x2c0
[   87.673845]  [<ffffffff8108ba2b>] process_one_work+0x1eb/0x530
[   87.673845]  [<ffffffff8108b9c9>] ? process_one_work+0x189/0x530
[   87.673845]  [<ffffffff8108c15b>] worker_thread+0x11b/0x4f0
[   87.673845]  [<ffffffff8108c040>] ? rescuer_thread+0x290/0x290
[   87.673845]  [<ffffffff810939c4>] kthread+0xe4/0x100
[   87.673845]  [<ffffffff810938e0>] ? kthread_create_on_node+0x220/0x220
[   87.673845]  [<ffffffff817e7c7c>] ret_from_fork+0x7c/0xb0
[   87.673845]  [<ffffffff810938e0>] ? kthread_create_on_node+0x220/0x220

-------------------

It's because that we miscalculate @rbio->bbio->error so that it doesn't
reach maximum of tolerable errors while it should have.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Tested-by: Satoru Takeuchi<takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:45 -07:00
Anand Jain b2373f255c btrfs: create sprout should rename fsid on the sysfs as well
Creating sprout will change the fsid of the mounted root.
do the same on the sysfs as well.

reproducer:
 mount /dev/sdb /btrfs (seed disk)
 btrfs dev add /dev/sdc /btrfs
 mount -o rw,remount /btrfs
 btrfs dev del /dev/sdb /btrfs
 mount /dev/sdb /btrfs

Error:
kobject_add_internal failed for fe350492-dc28-4051-a601-e017b17e6145 with -EEXIST, don't try to register things with the same name in the same directory.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:44 -07:00
Anand Jain 49c6f736f3 btrfs: dev replace should replace the sysfs entry
when we replace the device its corresponding sysfs
entry has to be replaced as well

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:44 -07:00
Anand Jain 0d39376aa2 btrfs: dev add should add its sysfs entry
we would need the device links to be created,
when device is added.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:43 -07:00
Anand Jain 99994cde9c btrfs: dev delete should remove sysfs entry
when we delete the device from the mounted btrfs,
we would need its corresponding sysfs enty to
be removed as well.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:42 -07:00
Anand Jain 9b4eaf43f4 btrfs: rename add_device_membership to btrfs_kobj_add_device
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:41 -07:00
Linus Torvalds e13d100beb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This fixes some lockups in btrfs reported with rc1.  It probably has
  some performance impact because it is backing off our spinning locks
  more often and switching to a blocking lock.  I'll be able to nail
  that down next week, but for now I want to get the lockups taken care
  of.

  Otherwise some more stack reduction and assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong error handle when the device is missing or is not writeable
  Btrfs: fix deadlock when mounting a degraded fs
  Btrfs: use bio_endio_nodec instead of open code
  Btrfs: fix NULL pointer crash when running balance and scrub concurrently
  btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
  Btrfs: fix broken free space cache after the system crashed
  Btrfs: make free space cache write out functions more readable
  Btrfs: remove unused wait queue in struct extent_buffer
  Btrfs: fix deadlocks with trylock on tree nodes
2014-06-21 14:21:43 -10:00
Miao Xie 8408c716d7 Btrfs: fix wrong error handle when the device is missing or is not writeable
The original bio might be submitted, so we shoud increase bi_remaining to
account for it when we deal with the error that the device is missing or
is not writeable, or we would skip the endio handle.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:56 -07:00
Miao Xie c55f139640 Btrfs: fix deadlock when mounting a degraded fs
The deadlock happened when we mount degraded filesystem, the reproduced
steps are following:
 # mkfs.btrfs -f -m raid1 -d raid1 <dev0> <dev1>
 # echo 1 > /sys/block/`basename <dev0>`/device/delete
 # mount -o degraded <dev1> <mnt>

The reason was that the counter -- bi_remaining was wrong. If the missing
or unwriteable device was the last device in the mapping array, we would
not submit the original bio, so we shouldn't increase bi_remaining of it
in btrfs_end_bio(), or we would skip the final endio handle.

Fix this problem by adding a flag into btrfs bio structure. If we submit
the original bio, we will set the flag, and we increase bi_remaining counter,
or we don't.

Though there is another way to fix it -- decrease bi_remaining counter of the
original bio when we make sure the original bio is not submitted, this method
need add more check and is easy to make mistake.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:56 -07:00
Miao Xie e990f16763 Btrfs: use bio_endio_nodec instead of open code
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:55 -07:00
Wang Shilong 298a8f9cf1 Btrfs: fix NULL pointer crash when running balance and scrub concurrently
While running balance, scrub, fsstress concurrently we hit the
following kernel crash:

[56561.448845] BTRFS info (device sde): relocating block group 11005853696 flags 132
[56561.524077] BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
[56561.524237] IP: [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.524297] PGD 9be28067 PUD 7f3dd067 PMD 0
[56561.524325] Oops: 0000 [#1] SMP
[....]
[56561.527237] Call Trace:
[56561.527309]  [<ffffffffa038980e>] scrub_enumerate_chunks+0x24e/0x490 [btrfs]
[56561.527392]  [<ffffffff810abe00>] ? abort_exclusive_wait+0x50/0xb0
[56561.527476]  [<ffffffffa038add4>] btrfs_scrub_dev+0x1a4/0x530 [btrfs]
[56561.527561]  [<ffffffffa0368107>] btrfs_ioctl+0x13f7/0x2a90 [btrfs]
[56561.527639]  [<ffffffff811c82f0>] do_vfs_ioctl+0x2e0/0x4c0
[56561.527712]  [<ffffffff8109c384>] ? vtime_account_user+0x54/0x60
[56561.527788]  [<ffffffff810f768c>] ? __audit_syscall_entry+0x9c/0xf0
[56561.527870]  [<ffffffff811c8551>] SyS_ioctl+0x81/0xa0
[56561.527941]  [<ffffffff815707f7>] tracesys+0xdd/0xe2
[...]
[56561.528304] RIP  [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.528395]  RSP <ffff88004c0f5be8>
[56561.528454] CR2: 0000000000000078

This is because in btrfs_relocate_chunk(), we will free @bdev directly while
scrub may still hold extent mapping, and may access freed memory.

Fix this problem by wrapping freeing @bdev work into free_extent_map() which
is based on reference count.

Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:55 -07:00
Qu Wenruo ced96edc48 btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
When run scrub with balance, sometimes -ENOENT will be returned, since
in scrub_enumerate_chunks() will search dev_extent in *COMMIT_ROOT*, but
btrfs_lookup_block_group() will search block group in *MEMORY*, so if a
chunk is removed but not committed, -ENOENT will be returned.

However, there is no need to stop scrubbing since other chunks may be
scrubbed without problem.

So this patch changes the behavior to skip removed chunks and continue
to scrub the rest.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Miao Xie e570fd27f2 Btrfs: fix broken free space cache after the system crashed
When we mounted the filesystem after the crash, we got the following
message:
  BTRFS error (device xxx): block group xxxx has wrong amount of free space
  BTRFS error (device xxx): failed to load free space cache for block group xxx

It is because we didn't update the metadata of the allocated space (in extent
tree) until the file data was written into the disk. During this time, there was
no information about the allocated spaces in either the extent tree nor the
free space cache. when we wrote out the free space cache at this time (commit
transaction), those spaces were lost. In fact, only the free space that is
used to store the file data had this problem, the others didn't because
the metadata of them is updated in the same transaction context.

There are many methods which can fix the above problem
- track the allocated space, and write it out when we write out the free
  space cache
- account the size of the allocated space that is used to store the file
  data, if the size is not zero, don't write out the free space cache.

The first one is complex and may make the performance drop down.
This patch chose the second method, we use a per-block-group variant to
account the size of that allocated space. Besides that, we also introduce
a per-block-group read-write semaphore to avoid the race between
the allocation and the free space cache write out.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Miao Xie 5349d6c3ff Btrfs: make free space cache write out functions more readable
This patch makes the free space cache write out functions more readable,
and beisdes that, it also reduces the stack space that the function --
__btrfs_write_out_cache uses from 194bytes to 144bytes.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Filipe Manana 46fefe41b5 Btrfs: remove unused wait queue in struct extent_buffer
The lock_wq wait queue is not used anywhere, therefore just remove it.
On a x86_64 system, this reduced sizeof(struct extent_buffer) from 320
bytes down to 296 bytes, which means a 4Kb page can now be used for
13 extent buffers instead of 12.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:28 -07:00
Chris Mason ea4ebde02e Btrfs: fix deadlocks with trylock on tree nodes
The Btrfs tree trylock function is poorly named.  It always takes
the spinlock and backs off if the blocking lock is held.  This
can lead to surprising lockups because people expect it to really be a
trylock.

This commit makes it a pure trylock, both for the spinlock and the
blocking lock.  It also reworks the nested lock handling slightly to
avoid taking the read lock while a spinning write lock might be held.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:19:55 -07:00
Linus Torvalds 16d52ef7c0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull more btrfs updates from Chris Mason:
 "This has a few fixes since our last pull and a new ioctl for doing
  btree searches from userland.  It's very similar to the existing
  ioctl, but lets us return larger items back down to the app"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix error handling in create_pending_snapshot
  btrfs: fix use of uninit "ret" in end_extent_writepage()
  btrfs: free ulist in qgroup_shared_accounting() error path
  Btrfs: fix qgroups sanity test crash or hang
  btrfs: prevent RCU warning when dereferencing radix tree slot
  Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
  btrfs: new ioctl TREE_SEARCH_V2
  btrfs: tree_search, search_ioctl: direct copy to userspace
  btrfs: new function read_extent_buffer_to_user
  btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
  btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
  btrfs: tree_search, search_ioctl: accept varying buffer
  btrfs: tree_search: eliminate redundant nr_items check
2014-06-14 19:48:43 -05:00
Eric Sandeen 47a306a748 btrfs: fix error handling in create_pending_snapshot
fcebe456 cut and pasted some code to a later point
in create_pending_snapshot(), but didn't switch
to the appropriate error handling for this stage
of the function.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:30 -07:00
Eric Sandeen 3e2426bd0e btrfs: fix use of uninit "ret" in end_extent_writepage()
If this condition in end_extent_writepage() is false:

	if (tree->ops && tree->ops->writepage_end_io_hook)

we will then test an uninitialized "ret" at:

	ret = ret < 0 ? ret : -EIO;

The test for ret is for the case where ->writepage_end_io_hook
failed, and we'd choose that ret as the error; but if
there is no ->writepage_end_io_hook, nothing sets ret.

Initializing ret to 0 should be sufficient; if
writepage_end_io_hook wasn't set, (!uptodate) means
non-zero err was passed in, so we choose -EIO in that case.

Signed-of-by: Eric Sandeen <sandeen@redhat.com>

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:28 -07:00
Eric Sandeen d737278091 btrfs: free ulist in qgroup_shared_accounting() error path
If tmp = ulist_alloc(GFP_NOFS) fails, we return without
freeing the previously allocated qgroups = ulist_alloc(GFP_NOFS)
and cause a memory leak.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:26 -07:00
Filipe Manana b050f9f6dd Btrfs: fix qgroups sanity test crash or hang
Often when running the qgroups sanity test, a crash or a hang happened.
This is because the extent buffer the test uses for the root node doesn't
have an header level explicitly set, making it have a random level value.
This is a problem when it's not zero for the btrfs_search_slot() calls
the test ends up doing, resulting in crashes or hangs such as the following:

[ 6454.127192] Btrfs loaded, debug=on, assert=on, integrity-checker=on
(...)
[ 6454.127760] BTRFS: selftest: Running qgroup tests
[ 6454.127964] BTRFS: selftest: Running test_test_no_shared_qgroup
[ 6454.127966] BTRFS: selftest: Qgroup basic add
[ 6480.152005] BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:5383]
[ 6480.152005] Modules linked in: btrfs(+) xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc i2c_piix4 i2c_core pcspkr evbug psmouse serio_raw e1000 [last unloaded: btrfs]
[ 6480.152005] irq event stamp: 188448
[ 6480.152005] hardirqs last  enabled at (188447): [<ffffffff8168ef5c>] restore_args+0x0/0x30
[ 6480.152005] hardirqs last disabled at (188448): [<ffffffff81698e6a>] apic_timer_interrupt+0x6a/0x80
[ 6480.152005] softirqs last  enabled at (188446): [<ffffffff810516cf>] __do_softirq+0x1cf/0x450
[ 6480.152005] softirqs last disabled at (188441): [<ffffffff81051c25>] irq_exit+0xb5/0xc0
[ 6480.152005] CPU: 0 PID: 5383 Comm: modprobe Not tainted 3.15.0-rc8-fdm-btrfs-next-33+ #4
[ 6480.152005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 6480.152005] task: ffff8802146125a0 ti: ffff8800d0d00000 task.ti: ffff8800d0d00000
[ 6480.152005] RIP: 0010:[<ffffffff81349a63>]  [<ffffffff81349a63>] __write_lock_failed+0x13/0x20
[ 6480.152005] RSP: 0018:ffff8800d0d038e8  EFLAGS: 00000287
[ 6480.152005] RAX: 0000000000000000 RBX: ffffffff8168ef5c RCX: 000005deb8525852
[ 6480.152005] RDX: 0000000000000000 RSI: 0000000000001d45 RDI: ffff8802105000b8
[ 6480.152005] RBP: ffff8800d0d038e8 R08: fffffe12710f63db R09: ffffffffa03196fb
[ 6480.152005] R10: ffff8802146125a0 R11: ffff880214612e28 R12: ffff8800d0d03858
[ 6480.152005] R13: 0000000000000000 R14: ffff8800d0d00000 R15: ffff8802146125a0
[ 6480.152005] FS:  00007f14ff804700(0000) GS:ffff880215e00000(0000) knlGS:0000000000000000
[ 6480.152005] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 6480.152005] CR2: 00007fff4df0dac8 CR3: 00000000d1796000 CR4: 00000000000006f0
[ 6480.152005] Stack:
[ 6480.152005]  ffff8800d0d03908 ffffffff810ae967 0000000000000001 ffff8802105000b8
[ 6480.152005]  ffff8800d0d03938 ffffffff8168e57e ffffffffa0319c16 0000000000000007
[ 6480.152005]  ffff880210500000 ffff880210500100 ffff8800d0d039b8 ffffffffa0319c16
[ 6480.152005] Call Trace:
[ 6480.152005]  [<ffffffff810ae967>] do_raw_write_lock+0x47/0xa0
[ 6480.152005]  [<ffffffff8168e57e>] _raw_write_lock+0x5e/0x80
[ 6480.152005]  [<ffffffffa0319c16>] ? btrfs_tree_lock+0x116/0x270 [btrfs]
[ 6480.152005]  [<ffffffffa0319c16>] btrfs_tree_lock+0x116/0x270 [btrfs]
[ 6480.152005]  [<ffffffffa02b2acb>] btrfs_lock_root_node+0x3b/0x50 [btrfs]
[ 6480.152005]  [<ffffffffa02b81a6>] btrfs_search_slot+0x916/0xa20 [btrfs]
[ 6480.152005]  [<ffffffff811a727f>] ? create_object+0x23f/0x300
[ 6480.152005]  [<ffffffffa02b9958>] btrfs_insert_empty_items+0x78/0xd0 [btrfs]
[ 6480.152005]  [<ffffffffa036041a>] insert_normal_tree_ref.constprop.4+0xa2/0x19a [btrfs]
[ 6480.152005]  [<ffffffffa03605c3>] test_no_shared_qgroup+0xb1/0x1ca [btrfs]
[ 6480.152005]  [<ffffffff8108cad6>] ? local_clock+0x16/0x30
[ 6480.152005]  [<ffffffffa035ef8e>] btrfs_test_qgroups+0x1ae/0x1d7 [btrfs]
[ 6480.152005]  [<ffffffffa03a69d2>] ? ftrace_define_fields_btrfs_space_reservation+0xfd/0xfd [btrfs]
[ 6480.152005]  [<ffffffffa03a6a86>] init_btrfs_fs+0xb4/0x153 [btrfs]
[ 6480.152005]  [<ffffffff81000352>] do_one_initcall+0x102/0x150
[ 6480.152005]  [<ffffffff8103d223>] ? set_memory_nx+0x43/0x50
[ 6480.152005]  [<ffffffff81682668>] ? set_section_ro_nx+0x6d/0x74
[ 6480.152005]  [<ffffffff810d91cc>] load_module+0x1cdc/0x2630
(...)

Therefore initialize the extent buffer as an empty leaf (level 0).

Issue easy to reproduce when btrfs is built as a module via:

    $ for ((i = 1; i <= 1000000; i++)); do rmmod btrfs; modprobe btrfs; done

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:24 -07:00
Sasha Levin f1e3c28949 btrfs: prevent RCU warning when dereferencing radix tree slot
Mark the dereference as protected by lock. Not doing so triggers
an RCU warning since the radix tree assumed that RCU is in use.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:22 -07:00
Wang Shilong 5fbc7c59fd Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
Steps to reproduce:

 # mkfs.btrfs -f /dev/sd[b-f] -m raid5 -d raid5
 # mkfs.ext4 /dev/sdc --->corrupt one of btrfs device
 # mount /dev/sdb /mnt -o degraded
 # btrfs scrub start -BRd /mnt

This is because readahead would skip missing device, this is not true
for RAID5/6, because REQ_GET_READ_MIRRORS return 1 for RAID5/6 block
mapping. If expected data locates in missing device, readahead thread
would not call __readahead_hook() which makes event @rc->elems=0
wait forever.

Fix this problem by checking return value of btrfs_map_block(),we
can only skip missing device safely if there are several mirrors.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:21 -07:00
Gerhard Heift cc68a8a5a4 btrfs: new ioctl TREE_SEARCH_V2
This new ioctl call allows the user to supply a buffer of varying size in which
a tree search can store its results. This is much more flexible if you want to
receive items which are larger than the current fixed buffer of 3992 bytes or
if you want to fetch more items at once. Items larger than this buffer are for
example some of the type EXTENT_CSUM.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-13 09:52:19 -07:00
Gerhard Heift ba346b357d btrfs: tree_search, search_ioctl: direct copy to userspace
By copying each found item seperatly to userspace, we do not need extra
buffer in the kernel.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:22:05 -07:00
Gerhard Heift 550ac1d85e btrfs: new function read_extent_buffer_to_user
This new function reads the content of an extent directly to user memory.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:56 -07:00
Gerhard Heift 9b6e817d02 btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
If an item in tree_search is too large to be stored in the given buffer, return
the needed size (including the header).

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:47 -07:00
Gerhard Heift 8f5f6178f3 btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
In copy_to_sk, if an item is too large for the given buffer, it now returns
-EOVERFLOW instead of copying a search_header with len = 0. For backward
compatibility for the first item it still copies such a header to the buffer,
but not any other following items, which could have fitted.

tree_search changes -EOVERFLOW back to 0 to behave similiar to the way it
behaved before this patch.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:39 -07:00
Gerhard Heift 1254444288 btrfs: tree_search, search_ioctl: accept varying buffer
rewrite search_ioctl to accept a buffer with varying size

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:26 -07:00
Gerhard Heift 25c9bc2e2b btrfs: tree_search: eliminate redundant nr_items check
If the amount of items reached the given limit of nr_items, we can leave
copy_to_sk without updating the key. Also by returning 1 we leave the loop in
search_ioctl without rechecking if we reached the given limit.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:20:39 -07:00
Linus Torvalds 16b9057804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...
2014-06-12 10:30:18 -07:00
Al Viro 9c1d5284c7 Merge commit '9f12600fe425bc28f0ccba034a77783c09c15af4' into for-linus
Backmerge of dcache.c changes from mainline.  It's that, or complete
rebase...

Conflicts:
	fs/splice.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-12 00:28:09 -04:00