Commit Graph

5511 Commits

Author SHA1 Message Date
David Sterba
66ac9fe7ba btrfs: add check to sysfs handler of label
Add a sanity check for the fs_info as we will dereference it, similar to
what the 'store features' handler does.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
ee6111386a btrfs: add read-only check to sysfs handler of features
We don't want to trigger the change on a read-only filesystem, similar
to what the label handler does.

Signed-off-by: David Sterba <dsterba@suse.cz>
2016-05-06 15:22:49 +02:00
David Sterba
e6c11f9a46 btrfs: reuse existing variable in scrub_stripe, reduce stack usage
The key variable occupies 17 bytes, the key_start is used once, we can
simply reuse existing 'key' for that purpose. As the key is not a simple
type, compiler doest not do it on itself.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
49a3c4d9b6 btrfs: use dynamic allocation for root item in create_subvol
The size of root item is more than 400 bytes, which is quite a lot of
stack space. As we do IO from inside the subvolume ioctls, we should
keep the stack usage low in case the filesystem is on top of other
layers (NFS, device mapper, iscsi, etc).

Reviewed-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
153519559a btrfs: clone: use vmalloc only as fallback for nodesize bufer
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
2f91306a37 btrfs: send: use vmalloc only as fallback for clone_sources_tmp
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
c03d01f340 btrfs: send: use vmalloc only as fallback for clone_roots
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
e55d1153db btrfs: send: use temporary variable to store allocation size
We're going to use the argument multiple times later.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
eb5b75fe2e btrfs: send: use vmalloc only as fallback for read_buf
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
6ff48ce06b btrfs: send: use vmalloc only as fallback for send_buf
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
Anand Jain
779bf3fefa btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex
When the replace target fails, the target device will be taken
out of fs device list, scratch + update_dev_time and freed. However
we could do the scratch  + update_dev_time and free part after the
device has been taken out of device list, so that we don't have to
hold the device_list_mutex and uuid_mutex locks.

Reported issue:

[ 5375.718845] ======================================================
[ 5375.718846] [ INFO: possible circular locking dependency detected ]
[ 5375.718849] 4.4.5-scst31x-debug-11+ #40 Not tainted
[ 5375.718849] -------------------------------------------------------
[ 5375.718851] btrfs-health/4662 is trying to acquire lock:
[ 5375.718861]  (sb_writers){.+.+.+}, at: [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.718862]
[ 5375.718862] but task is already holding lock:
[ 5375.718907]  (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs]
[ 5375.718907]
[ 5375.718907] which lock already depends on the new lock.
[ 5375.718907]
[ 5375.718908]
[ 5375.718908] the existing dependency chain (in reverse order) is:
[ 5375.718911]
[ 5375.718911] -> #3 (&fs_devs->device_list_mutex){+.+.+.}:
[ 5375.718917]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718921]        [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0
[ 5375.718940]        [<ffffffffa0219bf6>] btrfs_show_devname+0x36/0x210 [btrfs]
[ 5375.718945]        [<ffffffff81267079>] show_vfsmnt+0x49/0x150
[ 5375.718948]        [<ffffffff81240b07>] m_show+0x17/0x20
[ 5375.718951]        [<ffffffff81246868>] seq_read+0x2d8/0x3b0
[ 5375.718955]        [<ffffffff8121df28>] __vfs_read+0x28/0xd0
[ 5375.718959]        [<ffffffff8121e806>] vfs_read+0x86/0x130
[ 5375.718962]        [<ffffffff8121f4c9>] SyS_read+0x49/0xa0
[ 5375.718966]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.718968]
[ 5375.718968] -> #2 (namespace_sem){+++++.}:
[ 5375.718971]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718974]        [<ffffffff81635199>] down_write+0x49/0x80
[ 5375.718977]        [<ffffffff81243593>] lock_mount+0x43/0x1c0
[ 5375.718979]        [<ffffffff81243c13>] do_add_mount+0x23/0xd0
[ 5375.718982]        [<ffffffff81244afb>] do_mount+0x27b/0xe30
[ 5375.718985]        [<ffffffff812459dc>] SyS_mount+0x8c/0xd0
[ 5375.718988]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.718991]
[ 5375.718991] -> #1 (&sb->s_type->i_mutex_key#5){+.+.+.}:
[ 5375.718994]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718996]        [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0
[ 5375.719001]        [<ffffffff8122d608>] path_openat+0x468/0x1360
[ 5375.719004]        [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719007]        [<ffffffff8121da7b>] do_sys_open+0x12b/0x210
[ 5375.719010]        [<ffffffff8121db7e>] SyS_open+0x1e/0x20
[ 5375.719013]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.719015]
[ 5375.719015] -> #0 (sb_writers){.+.+.+}:
[ 5375.719018]        [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0
[ 5375.719021]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.719026]        [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0
[ 5375.719028]        [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.719031]        [<ffffffff81242eb4>] mnt_want_write+0x24/0x50
[ 5375.719035]        [<ffffffff8122ded2>] path_openat+0xd32/0x1360
[ 5375.719037]        [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719040]        [<ffffffff8121d8a4>] file_open_name+0xe4/0x130
[ 5375.719043]        [<ffffffff8121d923>] filp_open+0x33/0x60
[ 5375.719073]        [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs]
[ 5375.719099]        [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs]
[ 5375.719123]        [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs]
[ 5375.719150]        [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs]
[ 5375.719175]        [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs]
[ 5375.719199]        [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs]
[ 5375.719222]        [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs]
[ 5375.719225]        [<ffffffff810a70df>] kthread+0xef/0x110
[ 5375.719229]        [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70
[ 5375.719230]
[ 5375.719230] other info that might help us debug this:
[ 5375.719230]
[ 5375.719233] Chain exists of:
[ 5375.719233]   sb_writers --> namespace_sem --> &fs_devs->device_list_mutex
[ 5375.719233]
[ 5375.719234]  Possible unsafe locking scenario:
[ 5375.719234]
[ 5375.719234]        CPU0                    CPU1
[ 5375.719235]        ----                    ----
[ 5375.719236]   lock(&fs_devs->device_list_mutex);
[ 5375.719238]                                lock(namespace_sem);
[ 5375.719239]                                lock(&fs_devs->device_list_mutex);
[ 5375.719241]   lock(sb_writers);
[ 5375.719241]
[ 5375.719241]  *** DEADLOCK ***
[ 5375.719241]
[ 5375.719243] 4 locks held by btrfs-health/4662:
[ 5375.719266]  #0:  (&fs_info->health_mutex){+.+.+.}, at: [<ffffffffa0246303>] health_kthread+0x63/0x490 [btrfs]
[ 5375.719293]  #1:  (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.+.}, at: [<ffffffffa02c6611>] btrfs_dev_replace_finishing+0x41/0x990 [btrfs]
[ 5375.719319]  #2:  (uuid_mutex){+.+.+.}, at: [<ffffffffa0282620>] btrfs_destroy_dev_replace_tgtdev+0x20/0x150 [btrfs]
[ 5375.719343]  #3:  (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs]
[ 5375.719343]
[ 5375.719343] stack backtrace:
[ 5375.719347] CPU: 2 PID: 4662 Comm: btrfs-health Not tainted 4.4.5-scst31x-debug-11+ #40
[ 5375.719348] Hardware name: Supermicro SYS-6018R-WTRT/X10DRW-iT, BIOS 1.0c 01/07/2015
[ 5375.719352]  0000000000000000 ffff880856f73880 ffffffff813529e3 ffffffff826182a0
[ 5375.719354]  ffffffff8260c090 ffff880856f738c0 ffffffff810d667c ffff880856f73930
[ 5375.719357]  ffff880861f32b40 ffff880861f32b68 0000000000000003 0000000000000004
[ 5375.719357] Call Trace:
[ 5375.719363]  [<ffffffff813529e3>] dump_stack+0x85/0xc2
[ 5375.719366]  [<ffffffff810d667c>] print_circular_bug+0x1ec/0x260
[ 5375.719369]  [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0
[ 5375.719373]  [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[ 5375.719376]  [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.719378]  [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0
[ 5375.719383]  [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0
[ 5375.719385]  [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0
[ 5375.719387]  [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.719389]  [<ffffffff81242eb4>] mnt_want_write+0x24/0x50
[ 5375.719393]  [<ffffffff8122ded2>] path_openat+0xd32/0x1360
[ 5375.719415]  [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs]
[ 5375.719418]  [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[ 5375.719420]  [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719423]  [<ffffffff810f615d>] ? rcu_read_lock_sched_held+0x6d/0x80
[ 5375.719426]  [<ffffffff81201a9b>] ? kmem_cache_alloc+0x26b/0x5d0
[ 5375.719430]  [<ffffffff8122e7d4>] ? getname_kernel+0x34/0x120
[ 5375.719433]  [<ffffffff8121d8a4>] file_open_name+0xe4/0x130
[ 5375.719436]  [<ffffffff8121d923>] filp_open+0x33/0x60
[ 5375.719462]  [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs]
[ 5375.719485]  [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs]
[ 5375.719506]  [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs]
[ 5375.719530]  [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs]
[ 5375.719554]  [<ffffffffa02c6b23>] ? btrfs_dev_replace_finishing+0x553/0x990 [btrfs]
[ 5375.719576]  [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs]
[ 5375.719598]  [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs]
[ 5375.719621]  [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs]
[ 5375.719641]  [<ffffffffa02463d8>] ? health_kthread+0x138/0x490 [btrfs]
[ 5375.719661]  [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs]
[ 5375.719663]  [<ffffffff810a70df>] kthread+0xef/0x110
[ 5375.719666]  [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200
[ 5375.719669]  [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70
[ 5375.719672]  [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200
[ 5375.719697] ------------[ cut here ]------------

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reported-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
Dan Carpenter
f5ecec3ce2 btrfs: send: silence an integer overflow warning
The "sizeof(*arg->clone_sources) * arg->clone_sources_count" expression
can overflow.  It causes several static checker warnings.  It's all
under CAP_SYS_ADMIN so it's not that serious but lets silence the
warnings.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
Luis de Bethencourt
41b34accb2 btrfs: avoid overflowing f_bfree
Since mixed block groups accounting isn't byte-accurate and f_bree is an
unsigned integer, it could overflow. Avoid this.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Suggested-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
Luis de Bethencourt
ae02d1bd07 btrfs: fix mixed block count of available space
Metadata for mixed block is already accounted in total data and should not
be counted as part of the free metadata space.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=114281
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
Austin S. Hemmelgarn
88be159c90 btrfs: allow balancing to dup with multi-device
Currently, we don't allow the user to try and rebalance to a dup profile
on a multi-device filesystem.  In most cases, this is a perfectly sensible
restriction as raid1 uses the same amount of space and provides better
protection.

However, when reshaping a multi-device filesystem down to a single device
filesystem, this requires the user to convert metadata and system chunks
to single profile before deleting devices, and then convert again to dup,
which leaves a period of time where metadata integrity is reduced.

This patch removes the single-device-only restriction from converting to
dup profile to remove this potential data integrity reduction.

Signed-off-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00
David Sterba
2355ac8495 btrfs: ioctl: reorder exclusive op check in RM_DEV
Move the op exclusivity check before the other code (same as in
ADD_DEV).

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 14:58:00 +02:00
David Sterba
58409edd2d btrfs: kill unused writepage_io_hook callback
It seems to be long time unused, since 2008 and
6885f308b5 ("Btrfs: Misc 2.6.25 updates").

Propagating the removal touches some code but has no functional effect.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 14:57:57 +02:00
Anand Jain
88acff64c6 btrfs: cleanup assigning next active device with a check
Creates helper fucntion as needed by the device delete
and replace operations. Also now it checks if the next
device being assigned is an active device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-04 10:41:08 +02:00
Anand Jain
8ed01abe7d btrfs: s_bdev is not null after missing replace
Yauhen reported in the ML that s_bdev is null at mount, and
s_bdev gets updated to some device when missing device is
replaced, as because bdev is null for missing device, things
gets matched up. Fix this by checking if s_bdev is set. I
didn't want to completely remove updating s_bdev because
the future multi device support at vfs layer may need it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reported-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-04 09:52:44 +02:00
Al Viro
9902af79c0 parallel lookups: actual switch to rwsem
ta-da!

The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.

lockdep side also might need more work

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:28 -04:00
Al Viro
84695ffee7 Merge getxattr prototype change into work.lookups
The rest of work.xattr stuff isn't needed for this branch
2016-05-02 19:45:47 -04:00
Anand Jain
ad8403df05 btrfs: pass the right error code to the btrfs_std_error
Also drop the newline from the message.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-02 17:50:13 +02:00
Christoph Hellwig
e259221763 fs: simplify the generic_write_sync prototype
The kiocb already has the new position, so use that.  The only interesting
case is AIO, where we currently don't bother updating ki_pos.  We're about
to free the kiocb after we're done, so we might as well update it to make
everyone's life simpler.

While we're at it also return the bytes written argument passed in if
we were successful so that the boilerplate error switch code in the
callers can go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig
dde0c2e798 fs: add IOCB_SYNC and IOCB_DSYNC
This will allow us to do per-I/O sync file writes, as required by a lot
of fileservers or storage targets.

XXX: Will need a few additional audits for O_DSYNC

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig
c8b8e32d70 direct-io: eliminate the offset argument to ->direct_IO
Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig
1af5bb491f filemap: remove the pos argument to generic_file_direct_write
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
David Sterba
210aa27768 btrfs: sink gfp parameter to convert_extent_bit
Single caller passes GFP_NOFS. We can get rid of the
gfpflags_allow_blocking checks as NOFS can block but does not recurse to
filesystem through reclaim.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 13:48:14 +02:00
David Sterba
059f791c6b btrfs: make state preallocation more speculative in __set_extent_bit
Similar to __clear_extent_bit, do not fail if the state preallocation
fails as we might not need it. One less BUG_ON.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
03bf538770 btrfs: untangle gotos a bit in convert_extent_bit
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
7ab5cb2a9e btrfs: untangle gotos a bit in __clear_extent_bit
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
b5a4ba14e0 btrfs: untangle gotos a bit in __set_extent_bit
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
2c53b912ae btrfs: sink gfp parameter to set_record_extent_bits
Single caller passes GFP_NOFS.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
3744dbeb70 btrfs: sink gfp parameter to set_extent_new
Single caller passes GFP_NOFS.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
018ed4f788 btrfs: sink gfp parameter to set_extent_defrag
Single caller passes GFP_NOFS.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
7cd8c7527c btrfs: sink gfp parameter to set_extent_delalloc
Callers pass GFP_NOFS and tests pass GFP_KERNEL, but using NOFS there
does not hurt. No need to pass the flags around.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
af6f8f604d btrfs: sink gfp parameter to clear_extent_dirty
Callers pass GFP_NOFS. No need to pass the flags around.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
f734c44a1b btrfs: sink gfp parameter to clear_record_extent_bits
Callers pass GFP_NOFS. No need to pass the flags around.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
91166212e0 btrfs: sink gfp parameter to clear_extent_bits
Callers pass GFP_NOFS and GFP_KERNEL. No need to pass the flags around.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
David Sterba
ceeb0ae7bf btrfs: sink gfp parameter to set_extent_bits
All callers pass GFP_NOFS.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29 11:01:47 +02:00
Jeff Mahoney
db6711600e btrfs: uapi/linux/btrfs_tree.h migration, item types and defines
The BTRFS_IOC_SEARCH_TREE ioctl returns file system items directly
to userspace.  In order to decode them, full type information is required.

Create a new header, btrfs_tree to contain these since most users won't
need them.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Jeff Mahoney
33ca913349 btrfs: uapi/linux/btrfs.h migration, move struct btrfs_ioctl_defrag_range_args
struct btrfs_ioctl_defrag_range_args is used by the BTRFS_IOC_DEFRAG_RANGE
ioctl.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Jeff Mahoney
04cd01dffb btrfs: uapi/linux/btrfs.h migration, move balance flags
The BTRFS_BALANCE_* flags are used by struct btrfs_ioctl_balance_args.flags
and btrfs_ioctl_balance_args.{data,meta,sys}.flags in the BTRFS_IOC_BALANCE
ioctl.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Jeff Mahoney
18db9ac644 btrfs: uapi/linux/btrfs.h migration, move feature flags
The compat/compat_ro/incompat feature flags are used by the feature set/get
ioctls.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Jeff Mahoney
83288b60bf btrfs: uapi/linux/btrfs.h migration, qgroup limit flags
The BTRFS_QGROUP_LIMIT_* flags are required to tell the kernel which
fields are valid when using the BTRFS_IOC_QGROUP_LIMIT ioctl.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Jeff Mahoney
d4ae133b2d btrfs: uapi/linux/btrfs.h migration, move BTRFS_LABEL_SIZE
BTRFS_LABEL_SIZE is required to define the BTRFS_IOC_GET_FSLABEL and
BTRFS_IOC_SET_FSLABEL ioctls.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 11:06:41 +02:00
Anand Jain
b5255456c5 btrfs: refactor btrfs_dev_replace_start for reuse
A refactor patch, and avoids user input verification in the
btrfs_dev_replace_start(), and so this function can be reused.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
fc23c246d7 btrfs: use fs_info directly
Local variable fs_info, contains root->fs_info, use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
735654ea91 btrfs: rename flags for vol args v2
Rename BTRFS_DEVICE_BY_ID so it's more descriptive that we specify the
device by id, it'll be part of the public API. The mask of supported
flags is also renamed, only for internal use.

The error code for unknown flags is EOPNOTSUPP, fixed.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
5c5c0df05d btrfs: rename btrfs_find_device_by_user_input
For clarity how we are going to find the device, let's call it a device
specifier, devspec for short. Also rename the arguments that are a
leftover from previous function purpose.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
418775a22b btrfs: use existing device constraints table btrfs_raid_array
We should avoid duplicating the device constraints, let's use the
btrfs_raid_array in btrfs_check_raid_min_devices.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
621292bae6 btrfs: introduce raid-type to error-code table, for minimum device constraint
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
3cc31a0d5b btrfs: pass number of devices to btrfs_check_raid_min_devices
Before this patch, btrfs_check_raid_min_devices would do an off-by-one
check of the constraints and not the miminmum check, as its name
suggests. This is not a problem if the only caller is device remove, but
would be confusing for others.

Add an argument with the exact number and let the caller(s) decide if
this needs any adjustments, like when device replace is running.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
David Sterba
f47ab2588e btrfs: rename __check_raid_min_devices
Underscores are for special functions, use the full prefix for better
stacktrace recognition.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
02feae3c55 btrfs: optimize check for stale device
Optimize check for stale device to only be checked when there is device
added or changed. If there is no update to the device, there is no need
to call btrfs_free_stale_device().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
6b526ed70c btrfs: introduce device delete by devid
This introduces new ioctl BTRFS_IOC_RM_DEV_V2, which uses enhanced struct
btrfs_ioctl_vol_args_v2 to carry devid as an user argument.

The patch won't delete the old ioctl interface and so kernel remains
backward compatible with user land progs.

Test case/script:
echo "0 $(blockdev --getsz /dev/sdf) linear /dev/sdf 0" | dmsetup create bad_disk
mkfs.btrfs -f -d raid1 -m raid1 /dev/sdd /dev/sde /dev/mapper/bad_disk
mount /dev/sdd /btrfs
dmsetup suspend bad_disk
echo "0 $(blockdev --getsz /dev/sdf) error /dev/sdf 0" | dmsetup load bad_disk
dmsetup resume bad_disk
echo "bad disk failed. now deleting/replacing"
btrfs dev del  3  /btrfs
echo $?
btrfs fi show /btrfs
umount /btrfs
btrfs-show-super /dev/sdd | egrep num_device
dmsetup remove bad_disk
wipefs -a /dev/sdf

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reported-by: Martin <m_btrfs@ml1.co.uk>
[ adjust messages, s/disk/device/ ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
42b6742715 btrfs: make use of btrfs_scratch_superblocks() in btrfs_rm_device()
With the previous patches now the btrfs_scratch_superblocks() is ready to
be used in btrfs_rm_device() so use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ use GFP_KERNEL ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
b3d1b1532f btrfs: enhance btrfs_find_device_by_user_input() to check device path
The operation of device replace and device delete follows same steps upto
some depth with in btrfs kernel, however they don't share codes. This
enhancement will help replace and delete to share codes.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
24fc572fe4 btrfs: make use of btrfs_find_device_by_user_input()
btrfs_rm_device() has a section of the code which can be replaced
btrfs_find_device_by_user_input()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
24e0474b59 btrfs: create helper btrfs_find_device_by_user_input()
The patch renames btrfs_dev_replace_find_srcdev() to
btrfs_find_device_by_user_input() and moves it to volumes.c, so that
delete device can use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
bd45ffbcb1 btrfs: clean up and optimize __check_raid_min_device()
__check_raid_min_device() which was pealed from btrfs_rm_device()
maintianed its original code to show the block move. This patch cleans up
__check_raid_min_device().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
f1fa7f2642 btrfs: create helper function __check_raid_min_devices()
move a section of btrfs_rm_device() code to check for min number of the
devices into the function __check_raid_min_devices()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:13 +02:00
Anand Jain
6cf86a006b btrfs: create a helper function to read the disk super
A part of code from btrfs_scan_one_device() is moved to a new function
btrfs_read_disk_super(), so that former function looks cleaner. (In this
process it also moves the code which ensures null terminating label). So
this creates easy opportunity to merge various duplicate codes on read
disk super. Earlier attempt to merge duplicate codes highlighted that
there were some issues for which there are duplicate codes (to read disk
super), however it was not clear what was the issue. So until we figure
that out, its better to keep them in a separate functions.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ use GFP_KERNEL, PAGE_CACHE_ removal related fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:59:04 +02:00
Liu Bo
cf25ce518e Btrfs: do not create empty block group if we have allocated data
Now we force to create empty block group to keep data profile alive,
however, in the below example, we eventually get an empty block group
while we're trying to get more space for other types (metadata/system),

- Before,
block group "A": size=2G, used=1.2G
block group "B": size=2G, used=512M

- After "btrfs balance start -dusage=50 mount_point",
block group "A": size=2G, used=(1.2+0.5)G
block group "C": size=2G, used=0

Since there is no data in block group C, it won't be deleted
automatically and we have to get the unused 2G until the next mount.

Balance itself just moves data and doesn't remove data, so it's safe
to not create such a empty block group if we already have data
 allocated in other block groups.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:41:47 +02:00
Chandan Rajendra
a2af23b7d7 Btrfs: __btrfs_buffered_write: Pass valid file offset when releasing delalloc space
The delalloc reserved space is calculated in terms of number of bytes
used by an integral number of blocks. This is done by rounding down the
value of 'pos' to the nearest multiple of sectorsize.

The file offset value held by 'pos' variable may not be aligned to
sectorsize and hence when passing it as an argument to
btrfs_delalloc_release_space(), we may end up releasing larger delalloc
space than we originally had reserved.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:41:47 +02:00
Liu Bo
894b36e35a Btrfs: cleanup error handling in extent_write_cached_pages
Now that we bail out immediately if ->writepage() returns an error,
we don't need an extra error to retain the error code.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:41:47 +02:00
Liu Bo
a91326679f Btrfs: make mapping->writeback_index point to the last written page
If sequential writer is writing in the middle of the page and it just redirties
the last written page by continuing from it.

In the above case this can end up with seeking back to that firstly redirtied
page after writing all the pages at the end of file because btrfs updates
mapping->writeback_index to 1 past the current one.

For non-cow filesystems, the cost is only about extra seek, while for cow
filesystems such as btrfs, it means unnecessary fragments.

To avoid it, we just need to continue writeback from the last written page.

This also updates btrfs to behave like what write_cache_pages() does, ie, bail
 out immediately if there is an error in writepage().

<Ref: https://www.spinics.net/lists/linux-btrfs/msg52628.html>

Reported-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:41:47 +02:00
Luke Dashjr
4c63c2454e btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl
32-bit ioctl uses these rather than the regular FS_IOC_* versions. They can
be handled in btrfs using the same code. Without this, 32-bit {ch,ls}attr
fail.

Signed-off-by: Luke Dashjr <luke-jr+git@utopios.org>
Cc: stable@vger.kernel.org
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:40:27 +02:00
Luis de Bethencourt
180e4d4700 btrfs: fix typos in comments
Correct a typo in the chunk_mutex name to make it grepable.

Since it is better to fix several typos at once, fixing the 2 more in the
same file.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Geert Uytterhoeven
6719afdcf8 Btrfs: Refactor btrfs_lock_cluster() to kill compiler warning
fs/btrfs/extent-tree.c: In function ‘btrfs_lock_cluster’:
fs/btrfs/extent-tree.c:6399: warning: ‘used_bg’ may be used uninitialized in this function

  - Replace "again: ... goto again;" by standard C "while (1) { ... }",
  - Move block not processed during the first iteration of the loop to the
    end of the loop, which allows to kill the "locked" variable,

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-and-Tested-by: Miao Xie <miaox@cn.fujitsu.com>
[ the compilation warning has been fixed by other patch, now we want to
  clean up the function ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Anand Jain
0713d90c75 btrfs: remove save_error_info()
Actually save_error_info() sets the FS state to error and nothing else.
Further the word save doesn't induce caffeine when compared to the word
set in what actually it does.

So to make it better understandable move save_error_info() code to its
only consumer itself.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Satoru Takeuchi
13f48dc909 btrfs: Simplify conditions about compress while mapping btrfs flags to inode flags
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Anand Jain
c5f4ccb2f7 btrfs: move error handling code together in ctree.h
Looks like we added the incompatible defines in between the error
handling defines in the file ctree.h. Now group them back.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Anand Jain
2351d743f6 btrfs: remove unused function btrfs_assert()
Apparently looks like ASSERT does the same intended job,
as intended btrfs_assert().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Anand Jain
34d9700702 btrfs: rename btrfs_std_error to btrfs_handle_fs_error
btrfs_std_error() handles errors, puts FS into readonly mode
(as of now). So its good idea to rename it to btrfs_handle_fs_error().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ edit changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28 10:36:54 +02:00
Al Viro
b296821a7c xattr_handler: pass dentry and inode as separate arguments of ->get()
... and do not assume they are already attached to each other

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10 20:48:24 -04:00
Al Viro
fc64005c93 don't bother with ->d_inode->i_sb - it's always equal to ->d_sb
... and neither can ever be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10 17:11:51 -04:00
Linus Torvalds
839a3f7657 Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "These are bug fixes, including a really old fsync bug, and a few trace
  points to help us track down problems in the quota code"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix file/data loss caused by fsync after rename and new inode
  btrfs: Reset IO error counters before start of device replacing
  btrfs: Add qgroup tracing
  Btrfs: don't use src fd for printk
  btrfs: fallback to vmalloc in btrfs_compare_tree
  btrfs: handle non-fatal errors in btrfs_qgroup_inherit()
  btrfs: Output more info for enospc_debug mount option
  Btrfs: fix invalid reference in replace_path
  Btrfs: Improve FL_KEEP_SIZE handling in fallocate
2016-04-09 10:41:34 -07:00
Linus Torvalds
93061f390f These changes contains a fix for overlayfs interacting with some
(badly behaved) dentry code in various file systems.  These have been
 reviewed by Al and the respective file system mtinainers and are going
 through the ext4 tree for convenience.
 
 This also has a few ext4 encryption bug fixes that were discovered in
 Android testing (yes, we will need to get these sync'ed up with the
 fs/crypto code; I'll take care of that).  It also has some bug fixes
 and a change to ignore the legacy quota options to allow for xfstests
 regression testing of ext4's internal quota feature and to be more
 consistent with how xfs handles this case.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "These changes contains a fix for overlayfs interacting with some
  (badly behaved) dentry code in various file systems.  These have been
  reviewed by Al and the respective file system mtinainers and are going
  through the ext4 tree for convenience.

  This also has a few ext4 encryption bug fixes that were discovered in
  Android testing (yes, we will need to get these sync'ed up with the
  fs/crypto code; I'll take care of that).  It also has some bug fixes
  and a change to ignore the legacy quota options to allow for xfstests
  regression testing of ext4's internal quota feature and to be more
  consistent with how xfs handles this case"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: ignore quota mount options if the quota feature is enabled
  ext4 crypto: fix some error handling
  ext4: avoid calling dquot_get_next_id() if quota is not enabled
  ext4: retry block allocation for failed DIO and DAX writes
  ext4: add lockdep annotations for i_data_sem
  ext4: allow readdir()'s of large empty directories to be interrupted
  btrfs: fix crash/invalid memory access on fsync when using overlayfs
  ext4 crypto: use dget_parent() in ext4_d_revalidate()
  ext4: use file_dentry()
  ext4: use dget_parent() in ext4_file_open()
  nfs: use file_dentry()
  fs: add file_dentry()
  ext4 crypto: don't let data integrity writebacks fail with ENOMEM
  ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()
2016-04-07 17:22:20 -07:00
Filipe Manana
56f23fdbb6 Btrfs: fix file/data loss caused by fsync after rename and new inode
If we rename an inode A (be it a file or a directory), create a new
inode B with the old name of inode A and under the same parent directory,
fsync inode B and then power fail, at log tree replay time we end up
removing inode A completely. If inode A is a directory then all its files
are gone too.

Example scenarios where this happens:
This is reproducible with the following steps, taken from a couple of
test cases written for fstests which are going to be submitted upstream
soon:

   # Scenario 1

   mkfs.btrfs -f /dev/sdc
   mount /dev/sdc /mnt
   mkdir -p /mnt/a/x
   echo "hello" > /mnt/a/x/foo
   echo "world" > /mnt/a/x/bar
   sync
   mv /mnt/a/x /mnt/a/y
   mkdir /mnt/a/x
   xfs_io -c fsync /mnt/a/x
   <power failure happens>

   The next time the fs is mounted, log tree replay happens and
   the directory "y" does not exist nor do the files "foo" and
   "bar" exist anywhere (neither in "y" nor in "x", nor the root
   nor anywhere).

   # Scenario 2

   mkfs.btrfs -f /dev/sdc
   mount /dev/sdc /mnt
   mkdir /mnt/a
   echo "hello" > /mnt/a/foo
   sync
   mv /mnt/a/foo /mnt/a/bar
   echo "world" > /mnt/a/foo
   xfs_io -c fsync /mnt/a/foo
   <power failure happens>

   The next time the fs is mounted, log tree replay happens and the
   file "bar" does not exists anymore. A file with the name "foo"
   exists and it matches the second file we created.

Another related problem that does not involve file/data loss is when a
new inode is created with the name of a deleted snapshot and we fsync it:

   mkfs.btrfs -f /dev/sdc
   mount /dev/sdc /mnt
   mkdir /mnt/testdir
   btrfs subvolume snapshot /mnt /mnt/testdir/snap
   btrfs subvolume delete /mnt/testdir/snap
   rmdir /mnt/testdir
   mkdir /mnt/testdir
   xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir
   <power failure>

   The next time the fs is mounted the log replay procedure fails because
   it attempts to delete the snapshot entry (which has dir item key type
   of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry,
   resulting in the following error that causes mount to fail:

   [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257
   [52174.512570] ------------[ cut here ]------------
   [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]()
   [52174.514681] BTRFS: Transaction aborted (error -2)
   [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc
   [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G        W       4.5.0-rc6-btrfs-next-27+ #1
   [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
   [52174.524053]  0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758
   [52174.524053]  0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd
   [52174.524053]  00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88
   [52174.524053] Call Trace:
   [52174.524053]  [<ffffffff81264e93>] dump_stack+0x67/0x90
   [52174.524053]  [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2
   [52174.524053]  [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs]
   [52174.524053]  [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50
   [52174.524053]  [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs]
   [52174.524053]  [<ffffffff8118f5e9>] ? iput+0xb0/0x284
   [52174.524053]  [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs]
   [52174.524053]  [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs]
   [52174.524053]  [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs]
   [52174.524053]  [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs]
   [52174.524053]  [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs]
   [52174.524053]  [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs]
   [52174.524053]  [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs]
   [52174.524053]  [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs]
   [52174.524053]  [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs]
   [52174.524053]  [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf
   [52174.524053]  [<ffffffff8117bafa>] mount_fs+0x67/0x131
   [52174.524053]  [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde
   [52174.524053]  [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs]
   [52174.524053]  [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf
   [52174.524053]  [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3
   [52174.524053]  [<ffffffff8117bafa>] mount_fs+0x67/0x131
   [52174.524053]  [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde
   [52174.524053]  [<ffffffff8119590f>] do_mount+0x8a6/0x9e8
   [52174.524053]  [<ffffffff811358dd>] ? strndup_user+0x3f/0x59
   [52174.524053]  [<ffffffff81195c65>] SyS_mount+0x77/0x9f
   [52174.524053]  [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b
   [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]---

Fix this by forcing a transaction commit when such cases happen.
This means we check in the commit root of the subvolume tree if there
was any other inode with the same reference when the inode we are
fsync'ing is a new inode (created in the current transaction).

Test cases for fstests, covering all the scenarios given above, were
submitted upstream for fstests:

  * fstests: generic test for fsync after renaming directory
    https://patchwork.kernel.org/patch/8694281/

  * fstests: generic test for fsync after renaming file
    https://patchwork.kernel.org/patch/8694301/

  * fstests: add btrfs test for fsync after snapshot deletion
    https://patchwork.kernel.org/patch/8670671/

Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-04-06 17:01:44 -07:00
Linus Torvalds
4a2d057e4f Merge branch 'PAGE_CACHE_SIZE-removal'
Merge PAGE_CACHE_SIZE removal patches from Kirill Shutemov:
 "PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
  ago with promise that one day it will be possible to implement page
  cache with bigger chunks than PAGE_SIZE.

  This promise never materialized.  And unlikely will.

  Let's stop pretending that pages in page cache are special.  They are
  not.

  The first patch with most changes has been done with coccinelle.  The
  second is manual fixups on top.

  The third patch removes macros definition"

[ I was planning to apply this just before rc2, but then I spaced out,
  so here it is right _after_ rc2 instead.

  As Kirill suggested as a possibility, I could have decided to only
  merge the first two patches, and leave the old interfaces for
  compatibility, but I'd rather get it all done and any out-of-tree
  modules and patches can trivially do the converstion while still also
  working with older kernels, so there is little reason to try to
  maintain the redundant legacy model.    - Linus ]

* PAGE_CACHE_SIZE-removal:
  mm: drop PAGE_CACHE_* and page_cache_{get,release} definition
  mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage
  mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
2016-04-04 10:50:24 -07:00
Kirill A. Shutemov
ea1754a084 mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage
Mostly direct substitution with occasional adjustment or removing
outdated comments.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Kirill A. Shutemov
09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Yauhen Kharuzhy
7ccefb98ce btrfs: Reset IO error counters before start of device replacing
If device replace entry was found on disk at mounting and its num_write_errors
stats counter has non-NULL value, then replace operation will never be
finished and -EIO error will be reported by btrfs_scrub_dev() because
this counter is never reset.

 # mount -o degraded /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 # btrfs replace status /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 Started on 25.Mar 07:28:00, canceled on 25.Mar 07:28:01 at 0.0%, 40 write errs, 0 uncorr. read errs
 # btrfs replace start -B 4 /dev/sdg /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 ERROR: ioctl(DEV_REPLACE_START) failed on "/media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/": Input/output error, no error

Reset num_write_errors and num_uncorrectable_read_errors counters in the
dev_replace structure before start of replacing.

Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
Mark Fasheh
0f5dcf8de9 btrfs: Add qgroup tracing
This patch adds tracepoints to the qgroup code on both the reporting side
(insert_dirty_extents) and the accounting side. Taken together it allows us
to see what qgroup operations have happened, and what their result was.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
Josef Bacik
c79b471330 Btrfs: don't use src fd for printk
The fd we pass in may not be on a btrfs file system, so don't try to do
BTRFS_I() on it.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
David Sterba
8f282f71ea btrfs: fallback to vmalloc in btrfs_compare_tree
The allocation of node could fail if the memory is too fragmented for a
given node size, practically observed with 64k.

http://article.gmane.org/gmane.comp.file-systems.btrfs/54689

Reported-and-tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
Mark Fasheh
918c2ee103 btrfs: handle non-fatal errors in btrfs_qgroup_inherit()
create_pending_snapshot() will go readonly on _any_ error return from
btrfs_qgroup_inherit(). If qgroups are enabled, a user can crash their fs by
just making a snapshot and asking it to inherit from an invalid qgroup. For
example:

$ btrfs sub snap -i 1/10 /btrfs/ /btrfs/foo

Will cause a transaction abort.

Fix this by only throwing errors in btrfs_qgroup_inherit() when we know
going readonly is acceptable.

The following xfstests test case reproduces this bug:

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"

  here=`pwd`
  tmp=/tmp/$$
  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
  	cd /
  	rm -f $tmp.*
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter

  # remove previous $seqres.full before test
  rm -f $seqres.full

  # real QA test starts here
  _supported_fs btrfs
  _supported_os Linux
  _require_scratch

  rm -f $seqres.full

  _scratch_mkfs
  _scratch_mount
  _run_btrfs_util_prog quota enable $SCRATCH_MNT
  # The qgroup '1/10' does not exist and should be silently ignored
  _run_btrfs_util_prog subvolume snapshot -i 1/10 $SCRATCH_MNT $SCRATCH_MNT/snap1

  _scratch_unmount

  echo "Silence is golden"

  status=0
  exit

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
Qu Wenruo
0305bc2793 btrfs: Output more info for enospc_debug mount option
As one user in mail list report reproducible balance ENOSPC error, it's
better to add more debug info for enospc_debug mount option.

Reported-by: Marc Haber <mh+linux-btrfs@zugschlus.de>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:22 +02:00
Liu Bo
264813acb1 Btrfs: fix invalid reference in replace_path
Dan Carpenter's static checker has found this error, it's introduced by
commit 64c043de46
("Btrfs: fix up read_tree_block to return proper error")

It's really supposed to 'break' the loop on error like others.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:29:18 +02:00
Davide Italiano
2a162ce932 Btrfs: Improve FL_KEEP_SIZE handling in fallocate
- We call inode_size_ok() only if FL_KEEP_SIZE isn't specified.
- As an optimisation we can skip the call if (off + len)
  isn't greater than the current size of the file. This operation
  is called under the lock so the less work we do, the better.
- If we call inode_size_ok() pass to it the correct value rather
  than a more conservative estimation.

Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04 16:25:28 +02:00
Linus Torvalds
82d2a348bb Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This has a few fixes Dave Sterba had queued up.  These are all pretty
  small, but since they were tested I decided against waiting for more"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: transaction_kthread() is not freezable
  btrfs: cleaner_kthread() doesn't need explicit freeze
  btrfs: do not write corrupted metadata blocks to disk
  btrfs: csum_tree_block: return proper errno value
2016-04-01 18:08:34 -05:00
Andreas Gruenbacher
b8a7a3a667 posix_acl: Inode acl caching fixes
When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation is responsible for updating the cached acl with
set_cached_acl().  This is done without locking at the VFS level, so
another task can call set_cached_acl() or forget_cached_acl() before the
get_acl inode operation gets to calling set_cached_acl(), and then
get_acl's call to set_cached_acl() results in caching an outdate ACL.

Prevent this from happening by setting the cached ACL pointer to a
task-specific sentinel value before calling the get_acl inode operation.
Move the responsibility for updating the cached ACL from the get_acl
inode operations to get_acl().  There, only set the cached ACL if the
sentinel value hasn't changed.

The sentinel values are chosen to have odd values.  Likewise, the value
of ACL_NOT_CACHED is odd.  In contrast, ACL object pointers always have
an even value (ACLs are aligned in memory).  This allows to distinguish
uncached ACLs values from ACL objects.

In addition, switch from guarding inode->i_acl and inode->i_default_acl
upates by the inode->i_lock spinlock to using xchg() and cmpxchg().

Filesystems that do not want ACLs returned from their get_acl inode
operations to be cached must call forget_cached_acl() to prevent the VFS
from doing so.

(Patch written by Al Viro and Andreas Gruenbacher.)

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-31 00:30:15 -04:00
Filipe Manana
de17e793b1 btrfs: fix crash/invalid memory access on fsync when using overlayfs
If the lower or upper directory of an overlayfs mount belong to a btrfs
file system and we fsync the file through the overlayfs' merged directory
we ended up accessing an inode that didn't belong to btrfs as if it were
a btrfs inode at btrfs_sync_file() resulting in a crash like the following:

[ 7782.588845] BUG: unable to handle kernel NULL pointer dereference at 0000000000000544
[ 7782.590624] IP: [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs]
[ 7782.591931] PGD 4d954067 PUD 1e878067 PMD 0
[ 7782.592016] Oops: 0002 [#6] PREEMPT SMP DEBUG_PAGEALLOC
[ 7782.592016] Modules linked in: btrfs overlay ppdev crc32c_generic evdev xor raid6_pq psmouse pcspkr sg serio_raw acpi_cpufreq parport_pc parport tpm_tis i2c_piix4 tpm i2c_core processor button loop autofs4 ext4 crc16 mbcache jbd2 sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs]
[ 7782.592016] CPU: 10 PID: 16437 Comm: xfs_io Tainted: G      D         4.5.0-rc6-btrfs-next-26+ #1
[ 7782.592016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[ 7782.592016] task: ffff88001b8d40c0 ti: ffff880137488000 task.ti: ffff880137488000
[ 7782.592016] RIP: 0010:[<ffffffffa030b7ab>]  [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs]
[ 7782.592016] RSP: 0018:ffff88013748be40  EFLAGS: 00010286
[ 7782.592016] RAX: 0000000080000000 RBX: ffff880133b30c88 RCX: 0000000000000001
[ 7782.592016] RDX: 0000000000000001 RSI: ffffffff8148fec0 RDI: 00000000ffffffff
[ 7782.592016] RBP: ffff88013748bec0 R08: 0000000000000001 R09: 0000000000000000
[ 7782.624248] R10: ffff88013748be40 R11: 0000000000000246 R12: 0000000000000000
[ 7782.624248] R13: 0000000000000000 R14: 00000000009305a0 R15: ffff880015e3be40
[ 7782.624248] FS:  00007fa83b9cb700(0000) GS:ffff88023ed40000(0000) knlGS:0000000000000000
[ 7782.624248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7782.624248] CR2: 0000000000000544 CR3: 00000001fa652000 CR4: 00000000000006e0
[ 7782.624248] Stack:
[ 7782.624248]  ffffffff8108b5cc ffff88013748bec0 0000000000000246 ffff8800b005ded0
[ 7782.624248]  ffff880133b30d60 8000000000000000 7fffffffffffffff 0000000000000246
[ 7782.624248]  0000000000000246 ffffffff81074f9b ffffffff8104357c ffff880015e3be40
[ 7782.624248] Call Trace:
[ 7782.624248]  [<ffffffff8108b5cc>] ? arch_local_irq_save+0x9/0xc
[ 7782.624248]  [<ffffffff81074f9b>] ? ___might_sleep+0xce/0x217
[ 7782.624248]  [<ffffffff8104357c>] ? __do_page_fault+0x3c0/0x43a
[ 7782.624248]  [<ffffffff811a2351>] vfs_fsync_range+0x8c/0x9e
[ 7782.624248]  [<ffffffff811a237f>] vfs_fsync+0x1c/0x1e
[ 7782.624248]  [<ffffffff811a24d6>] do_fsync+0x31/0x4a
[ 7782.624248]  [<ffffffff811a2700>] SyS_fsync+0x10/0x14
[ 7782.624248]  [<ffffffff81493617>] entry_SYSCALL_64_fastpath+0x12/0x6b
[ 7782.624248] Code: 85 c0 0f 85 e2 02 00 00 48 8b 45 b0 31 f6 4c 29 e8 48 ff c0 48 89 45 a8 48 8d 83 d8 00 00 00 48 89 c7 48 89 45 a0 e8 fc 43 18 e1 <f0> 41 ff 84 24 44 05 00 00 48 8b 83 58 ff ff ff 48 c1 e8 07 83
[ 7782.624248] RIP  [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs]
[ 7782.624248]  RSP <ffff88013748be40>
[ 7782.624248] CR2: 0000000000000544
[ 7782.661994] ---[ end trace 721e14960eb939bc ]---

This started happening since commit 4bacc9c923 (overlayfs: Make f_path
always point to the overlay and f_inode to the underlay) and even though
after this change we could still access the btrfs inode through
struct file->f_mapping->host or struct file->f_inode, we would end up
resulting in more similar issues later on at check_parent_dirs_for_sync()
because the dentry we got (from struct file->f_path.dentry) was from
overlayfs and not from btrfs, that is, we had no way of getting the dentry
that belonged to btrfs (we always got the dentry that belonged to
overlayfs).

The new patch from Miklos Szeredi, titled "vfs: add file_dentry()" and
recently submitted to linux-fsdevel, adds a file_dentry() API that allows
us to get the btrfs dentry from the input file and therefore being able
to fsync when the upper and lower directories belong to btrfs filesystems.

This issue has been reported several times by users in the mailing list
and bugzilla. A test case for xfstests is being submitted as well.

Fixes: 4bacc9c923 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=101951
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109791
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Cc: stable@vger.kernel.org
2016-03-30 19:03:13 -04:00
Chris Mason
232cad8413 Merge branch 'misc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.6 2016-03-24 17:36:13 -07:00
Jiri Kosina
ce63f891e1 btrfs: transaction_kthread() is not freezable
transaction_kthread() is calling try_to_freeze(), but that's just an
expeinsive no-op given the fact that the thread is not marked freezable.

After removing this, disk-io.c is now independent on freezer API.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22 10:08:47 +01:00
Jiri Kosina
838fe18877 btrfs: cleaner_kthread() doesn't need explicit freeze
cleaner_kthread() is not marked freezable, and therefore calling
try_to_freeze() in its context is a pointless no-op.

In addition to that, as has been clearly demonstrated by 80ad623edd
("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"), it's perfectly
valid / legal for cleaner_kthread() to stay scheduled out in an arbitrary
place during suspend (in that particular example that was waiting for
reading of extent pages), so there is no need to leave any traces of
freezer in this kthread.

Fixes: 80ad623edd ("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()")
Fixes: 6962491321 ("btrfs: clear PF_NOFREEZE in cleaner_kthread()")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22 10:08:47 +01:00
Alex Lyakas
0f805531da btrfs: do not write corrupted metadata blocks to disk
csum_dirty_buffer was issuing a warning in case the extent buffer
did not look alright, but was still returning success.
Let's return error in this case, and also add an additional sanity
check on the extent buffer header.
The caller up the chain may BUG_ON on this, for example flush_epd_write_bio will,
but it is better than to have a silent metadata corruption on disk.

Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22 10:08:12 +01:00
Alex Lyakas
8bd98f0e6b btrfs: csum_tree_block: return proper errno value
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22 10:07:43 +01:00
Linus Torvalds
968f3e374f Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "We have a good sized cleanup of our internal read ahead code, and the
  first series of commits from Chandan to enable PAGE_SIZE > sectorsize

  Otherwise, it's a normal series of cleanups and fixes, with many
  thanks to Dave Sterba for doing most of the patch wrangling this time"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (82 commits)
  btrfs: make sure we stay inside the bvec during __btrfs_lookup_bio_sums
  btrfs: Fix misspellings in comments.
  btrfs: Print Warning only if ENOSPC_DEBUG is enabled
  btrfs: scrub: silence an uninitialized variable warning
  btrfs: move btrfs_compression_type to compression.h
  btrfs: rename btrfs_print_info to btrfs_print_mod_info
  Btrfs: Show a warning message if one of objectid reaches its highest value
  Documentation: btrfs: remove usage specific information
  btrfs: use kbasename in btrfsic_mount
  Btrfs: do not collect ordered extents when logging that inode exists
  Btrfs: fix race when checking if we can skip fsync'ing an inode
  Btrfs: fix listxattrs not listing all xattrs packed in the same item
  Btrfs: fix deadlock between direct IO reads and buffered writes
  Btrfs: fix extent_same allowing destination offset beyond i_size
  Btrfs: fix file loss on log replay after renaming a file and fsync
  Btrfs: fix unreplayable log after snapshot delete + parent dir fsync
  Btrfs: fix lockdep deadlock warning due to dev_replace
  btrfs: drop unused argument in btrfs_ioctl_get_supported_features
  btrfs: add GET_SUPPORTED_FEATURES to the control device ioctls
  btrfs: change max_inline default to 2048
  ...
2016-03-21 18:12:42 -07:00
Chris Mason
389f239c53 btrfs: make sure we stay inside the bvec during __btrfs_lookup_bio_sums
Commit c40a3d38af (Btrfs: Compute and look up csums based on
sectorsized blocks) changes around how we walk the bios while looking up
crcs.  There's an inner loop that is jumping to the next bvec based on
sectors and before it derefs the next bvec, it needs to make sure we're
still in the bio.

In this case, the outer loop would have decided to stop moving forward
too, and the bvec deref is never actually used for anything.  But
CONFIG_DEBUG_PAGEALLOC catches it because we're outside our bio.

Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
2016-03-21 07:25:44 -07:00
Matthew Wilcox
c28f242063 btrfs: use radix_tree_iter_retry()
Even though this is a 'can't happen' situation, use the new
radix_tree_iter_retry() pattern to eliminate a goto.

[akpm@linux-foundation.org: fix btrfs build]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-17 15:09:34 -07:00
Adam Buchbinder
bb7ab3b92e btrfs: Fix misspellings in comments.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-14 15:05:02 +01:00
Ashish Samant
2e3fcb1ccd btrfs: Print Warning only if ENOSPC_DEBUG is enabled
Dont print warning for ENOSPC error unless ENOSPC_DEBUG is enabled. Use
btrfs_debug if it is enabled.

Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
[ preserve the WARN_ON ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-14 14:59:54 +01:00
Dan Carpenter
07c9a8e077 btrfs: scrub: silence an uninitialized variable warning
It's basically harmless if "ref_level" isn't initialized since it's only
used for an error message, but it causes a static checker warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11 17:21:59 +01:00
Anand Jain
ebb8765b2d btrfs: move btrfs_compression_type to compression.h
So that its better organized.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11 17:12:46 +01:00
Anand Jain
8ae1af3cd1 btrfs: rename btrfs_print_info to btrfs_print_mod_info
So that it indicates what it does.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11 17:12:46 +01:00
Satoru Takeuchi
3c1d84b71e Btrfs: Show a warning message if one of objectid reaches its highest value
It's better to show a warning message for the exceptional case
that one of objectid (in most case, inode number) reaches its
highest value. For example, if inode cache is off and this event
happens, we can't create any file even if there are not so many files.
This message ease detecting such problem.

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11 17:12:35 +01:00
Rasmus Villemoes
02def69fae btrfs: use kbasename in btrfsic_mount
This is more readable.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11 16:55:52 +01:00
Ingo Molnar
ec87e1cf7d Linux 4.5-rc7
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJW3LO0AAoJEHm+PkMAQRiGhewIAIVHA1+qSSXEHTFeuLRuYpiz
 +ptQUIjPJdakWm/XqOnwSG8SWUuD4XL6ysfNmLSZIdqXYBAPpAuwT1UA2FZhz0dN
 soZxMNleAvzHWRDFLqwjVdOVlTxS6CTTdEQNzi+3R0ZCADllsRcuj/GBIY+M8cr6
 LvxK8BnhDU+Au3gZQjaujTMO7fKG6gOq4wKz/U7RIG37A6rwW577kEfLg4ZgFwt9
 RVjsky5mrX9+4l3QFtox9ZC383P/0VZ6+vXwN2QH1/joDK4EvA8pCwsGTyjRJiqi
 fArHbS+mHyAtbPWJmDbVlQ5dkZJAqRgtWBydjQYoC16S4Bwdce2/FbhBiTgEQAo=
 =sqln
 -----END PGP SIGNATURE-----

Merge tag 'v4.5-rc7' into x86/asm, to pick up SMAP fix

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-07 09:27:30 +01:00
Linus Torvalds
2cdcb2b5b5 Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "Filipe nailed down a problem where tree log replay would do some work
  that orphan code wasn't expecting to be done yet, leading to BUG_ON"

* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix loading of orphan roots leading to BUG_ON
2016-03-04 17:31:32 -08:00
Filipe Manana
909c3a22da Btrfs: fix loading of orphan roots leading to BUG_ON
When looking for orphan roots during mount we can end up hitting a
BUG_ON() (at root-item.c:btrfs_find_orphan_roots()) if a log tree is
replayed and qgroups are enabled. This is because after a log tree is
replayed, a transaction commit is made, which triggers qgroup extent
accounting which in turn does backref walking which ends up reading and
inserting all roots in the radix tree fs_info->fs_root_radix, including
orphan roots (deleted snapshots). So after the log tree is replayed, when
finding orphan roots we hit the BUG_ON with the following trace:

[118209.182438] ------------[ cut here ]------------
[118209.183279] kernel BUG at fs/btrfs/root-tree.c:314!
[118209.184074] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[118209.185123] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic ppdev xor raid6_pq evdev sg parport_pc parport acpi_cpufreq tpm_tis tpm psmouse
processor i2c_piix4 serio_raw pcspkr i2c_core button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata
virtio_pci virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs]
[118209.186318] CPU: 14 PID: 28428 Comm: mount Tainted: G        W       4.5.0-rc5-btrfs-next-24+ #1
[118209.186318] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[118209.186318] task: ffff8801ec131040 ti: ffff8800af34c000 task.ti: ffff8800af34c000
[118209.186318] RIP: 0010:[<ffffffffa04237d7>]  [<ffffffffa04237d7>] btrfs_find_orphan_roots+0x1fc/0x244 [btrfs]
[118209.186318] RSP: 0018:ffff8800af34faa8  EFLAGS: 00010246
[118209.186318] RAX: 00000000ffffffef RBX: 00000000ffffffef RCX: 0000000000000001
[118209.186318] RDX: 0000000080000000 RSI: 0000000000000001 RDI: 00000000ffffffff
[118209.186318] RBP: ffff8800af34fb08 R08: 0000000000000001 R09: 0000000000000000
[118209.186318] R10: ffff8800af34f9f0 R11: 6db6db6db6db6db7 R12: ffff880171b97000
[118209.186318] R13: ffff8801ca9d65e0 R14: ffff8800afa2e000 R15: 0000160000000000
[118209.186318] FS:  00007f5bcb914840(0000) GS:ffff88023edc0000(0000) knlGS:0000000000000000
[118209.186318] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[118209.186318] CR2: 00007f5bcaceb5d9 CR3: 00000000b49b5000 CR4: 00000000000006e0
[118209.186318] Stack:
[118209.186318]  fffffbffffffffff 010230ffffffffff 0101000000000000 ff84000000000000
[118209.186318]  fbffffffffffffff 30ffffffffffffff 0000000000000101 ffff880082348000
[118209.186318]  0000000000000000 ffff8800afa2e000 ffff8800afa2e000 0000000000000000
[118209.186318] Call Trace:
[118209.186318]  [<ffffffffa042e2db>] open_ctree+0x1e37/0x21b9 [btrfs]
[118209.186318]  [<ffffffffa040a753>] btrfs_mount+0x97e/0xaed [btrfs]
[118209.186318]  [<ffffffff8108e1c0>] ? trace_hardirqs_on+0xd/0xf
[118209.186318]  [<ffffffff8117b87e>] mount_fs+0x67/0x131
[118209.186318]  [<ffffffff81192d2b>] vfs_kern_mount+0x6c/0xde
[118209.186318]  [<ffffffffa0409f81>] btrfs_mount+0x1ac/0xaed [btrfs]
[118209.186318]  [<ffffffff8108e1c0>] ? trace_hardirqs_on+0xd/0xf
[118209.186318]  [<ffffffff8108c26b>] ? lockdep_init_map+0xb9/0x1b3
[118209.186318]  [<ffffffff8117b87e>] mount_fs+0x67/0x131
[118209.186318]  [<ffffffff81192d2b>] vfs_kern_mount+0x6c/0xde
[118209.186318]  [<ffffffff81195637>] do_mount+0x8a6/0x9e8
[118209.186318]  [<ffffffff8119598d>] SyS_mount+0x77/0x9f
[118209.186318]  [<ffffffff81493017>] entry_SYSCALL_64_fastpath+0x12/0x6b
[118209.186318] Code: 64 00 00 85 c0 89 c3 75 24 f0 41 80 4c 24 20 20 49 8b bc 24 f0 01 00 00 4c 89 e6 e8 e8 65 00 00 85 c0 89 c3 74 11 83 f8 ef 75 02 <0f> 0b
4c 89 e7 e8 da 72 00 00 eb 1c 41 83 bc 24 00 01 00 00 00
[118209.186318] RIP  [<ffffffffa04237d7>] btrfs_find_orphan_roots+0x1fc/0x244 [btrfs]
[118209.186318]  RSP <ffff8800af34faa8>
[118209.230735] ---[ end trace 83938f987d85d477 ]---

So fix this by not treating the error -EEXIST, returned when attempting
to insert a root already inserted by the backref walking code, as an error.

The following test case for xfstests reproduces the bug:

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"
  tmp=/tmp/$$
  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
      _cleanup_flakey
      cd /
      rm -f $tmp.*
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter
  . ./common/dmflakey

  # real QA test starts here
  _supported_fs btrfs
  _supported_os Linux
  _require_scratch
  _require_dm_target flakey
  _require_metadata_journaling $SCRATCH_DEV

  rm -f $seqres.full

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

  _run_btrfs_util_prog quota enable $SCRATCH_MNT

  # Create 2 directories with one file in one of them.
  # We use these just to trigger a transaction commit later, moving the file from
  # directory a to directory b and doing an fsync against directory a.
  mkdir $SCRATCH_MNT/a
  mkdir $SCRATCH_MNT/b
  touch $SCRATCH_MNT/a/f
  sync

  # Create our test file with 2 4K extents.
  $XFS_IO_PROG -f -s -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foobar | _filter_xfs_io

  # Create a snapshot and delete it. This doesn't really delete the snapshot
  # immediately, just makes it inaccessible and invisible to user space, the
  # snapshot is deleted later by a dedicated kernel thread (cleaner kthread)
  # which is woke up at the next transaction commit.
  # A root orphan item is inserted into the tree of tree roots, so that if a
  # power failure happens before the dedicated kernel thread does the snapshot
  # deletion, the next time the filesystem is mounted it resumes the snapshot
  # deletion.
  _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap
  _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap

  # Now overwrite half of the extents we wrote before. Because we made a snapshpot
  # before, which isn't really deleted yet (since no transaction commit happened
  # after we did the snapshot delete request), the non overwritten extents get
  # referenced twice, once by the default subvolume and once by the snapshot.
  $XFS_IO_PROG -c "pwrite -S 0xbb 4K 8K" $SCRATCH_MNT/foobar | _filter_xfs_io

  # Now move file f from directory a to directory b and fsync directory a.
  # The fsync on the directory a triggers a transaction commit (because a file
  # was moved from it to another directory) and the file fsync leaves a log tree
  # with file extent items to replay.
  mv $SCRATCH_MNT/a/f $SCRATCH_MNT/a/b
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar

  echo "File digest before power failure:"
  md5sum $SCRATCH_MNT/foobar | _filter_scratch

  # Now simulate a power failure and mount the filesystem to replay the log tree.
  # After the log tree was replayed, we used to hit a BUG_ON() when processing
  # the root orphan item for the deleted snapshot. This is because when processing
  # an orphan root the code expected to be the first code inserting the root into
  # the fs_info->fs_root_radix radix tree, while in reallity it was the second
  # caller attempting to do it - the first caller was the transaction commit that
  # took place after replaying the log tree, when updating the qgroup counters.
  _flakey_drop_and_remount

  echo "File digest before after failure:"
  # Must match what he got before the power failure.
  md5sum $SCRATCH_MNT/foobar | _filter_scratch

  _unmount_flakey
  status=0
  exit

Fixes: 2d9e977610 ("Btrfs: use btrfs_get_fs_root in resolve_indirect_ref")
Cc: stable@vger.kernel.org  # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-03 15:28:59 -08:00
Filipe Manana
5e33a2bd7c Btrfs: do not collect ordered extents when logging that inode exists
When logging that an inode exists, for example as part of a directory
fsync operation, we were collecting any ordered extents for the inode but
we ended up doing nothing with them except tagging them as processed, by
setting the flag BTRFS_ORDERED_LOGGED on them, which prevented a
subsequent fsync of that inode (using the LOG_INODE_ALL mode) from
collecting and processing them. This created a time window where a second
fsync against the inode, using the fast path, ended up not logging the
checksums for the new extents but it logged the extents since they were
part of the list of modified extents. This happened because the ordered
extents were not collected and checksums were not yet added to the csum
tree - the ordered extents have not gone through btrfs_finish_ordered_io()
yet (which is where we add them to the csum tree by calling
inode.c:add_pending_csums()).

So fix this by not collecting an inode's ordered extents if we are logging
it with the LOG_INODE_EXISTS mode.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:47 -08:00
Filipe Manana
affc0ff902 Btrfs: fix race when checking if we can skip fsync'ing an inode
If we're about to do a fast fsync for an inode and btrfs_inode_in_log()
returns false, it's possible that we had an ordered extent in progress
(btrfs_finish_ordered_io() not run yet) when we noticed that the inode's
last_trans field was not greater than the id of the last committed
transaction, but shortly after, before we checked if there were any
ongoing ordered extents, the ordered extent had just completed and
removed itself from the inode's ordered tree, in which case we end up not
logging the inode, losing some data if a power failure or crash happens
after the fsync handler returns and before the transaction is committed.

Fix this by checking first if there are any ongoing ordered extents
before comparing the inode's last_trans with the id of the last committed
transaction - when it completes, an ordered extent always updates the
inode's last_trans before it removes itself from the inode's ordered
tree (at btrfs_finish_ordered_io()).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:44 -08:00
Filipe Manana
daac7ba61a Btrfs: fix listxattrs not listing all xattrs packed in the same item
In the listxattrs handler, we were not listing all the xattrs that are
packed in the same btree item, which happens when multiple xattrs have
a name that when crc32c hashed produce the same checksum value.

Fix this by processing them all.

The following test case for xfstests reproduces the issue:

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"
  tmp=/tmp/$$
  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
      cd /
      rm -f $tmp.*
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter
  . ./common/attr

  # real QA test starts here
  _supported_fs generic
  _supported_os Linux
  _require_scratch
  _require_attrs

  rm -f $seqres.full

  _scratch_mkfs >>$seqres.full 2>&1
  _scratch_mount

  # Create our test file with a few xattrs. The first 3 xattrs have a name
  # that when given as input to a crc32c function result in the same checksum.
  # This made btrfs list only one of the xattrs through listxattrs system call
  # (because it packs xattrs with the same name checksum into the same btree
  # item).
  touch $SCRATCH_MNT/testfile
  $SETFATTR_PROG -n user.foobar -v 123 $SCRATCH_MNT/testfile
  $SETFATTR_PROG -n user.WvG1c1Td -v qwerty $SCRATCH_MNT/testfile
  $SETFATTR_PROG -n user.J3__T_Km3dVsW_ -v hello $SCRATCH_MNT/testfile
  $SETFATTR_PROG -n user.something -v pizza $SCRATCH_MNT/testfile
  $SETFATTR_PROG -n user.ping -v pong $SCRATCH_MNT/testfile

  # Now call getfattr with --dump, which calls the listxattrs system call.
  # It should list all the xattrs we have set before.
  $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/testfile | _filter_scratch

  status=0
  exit

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:41 -08:00
Filipe Manana
ade770294d Btrfs: fix deadlock between direct IO reads and buffered writes
While running a test with a mix of buffered IO and direct IO against
the same files I hit a deadlock reported by the following trace:

[11642.140352] INFO: task kworker/u32:3:15282 blocked for more than 120 seconds.
[11642.142452]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.143982] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.146332] kworker/u32:3   D ffff880230ef7988 [11642.147737] systemd-journald[571]: Sent WATCHDOG=1 notification.
[11642.149771]     0 15282      2 0x00000000
[11642.151205] Workqueue: btrfs-flush_delalloc btrfs_flush_delalloc_helper [btrfs]
[11642.154074]  ffff880230ef7988 0000000000000246 0000000000014ec0 ffff88023ec94ec0
[11642.156722]  ffff880233fe8f80 ffff880230ef8000 ffff88023ec94ec0 7fffffffffffffff
[11642.159205]  0000000000000002 ffffffff8147b7f9 ffff880230ef79a0 ffffffff8147b541
[11642.161403] Call Trace:
[11642.162129]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.163396]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.164871]  [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109
[11642.167020]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.167931]  [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197
[11642.182320]  [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf
[11642.183762]  [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33
[11642.185308]  [<ffffffff810b0f61>] ? ktime_get+0x41/0x52
[11642.186782]  [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102
[11642.188217]  [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102
[11642.189626]  [<ffffffff8147b814>] bit_wait_io+0x1b/0x39
[11642.190803]  [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90
[11642.192158]  [<ffffffff8111829f>] __lock_page+0x66/0x68
[11642.193379]  [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a
[11642.194831]  [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs]
[11642.197068]  [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs]
[11642.199188]  [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs]
[11642.200723]  [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs]
[11642.202465]  [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs]
[11642.203836]  [<ffffffff811236bc>] do_writepages+0x23/0x2c
[11642.205624]  [<ffffffff811198c9>] __filemap_fdatawrite_range+0x5a/0x61
[11642.207057]  [<ffffffff81119946>] filemap_fdatawrite_range+0x13/0x15
[11642.208529]  [<ffffffffa044f87e>] btrfs_start_ordered_extent+0xd0/0x1a1 [btrfs]
[11642.210375]  [<ffffffffa0462613>] ? btrfs_scrubparity_helper+0x140/0x33a [btrfs]
[11642.212132]  [<ffffffffa044f974>] btrfs_run_ordered_extent_work+0x25/0x34 [btrfs]
[11642.213837]  [<ffffffffa046262f>] btrfs_scrubparity_helper+0x15c/0x33a [btrfs]
[11642.215457]  [<ffffffffa046293b>] btrfs_flush_delalloc_helper+0xe/0x10 [btrfs]
[11642.217095]  [<ffffffff8106483e>] process_one_work+0x256/0x48b
[11642.218324]  [<ffffffff81064f20>] worker_thread+0x1f5/0x2a7
[11642.219466]  [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289
[11642.220801]  [<ffffffff8106a500>] kthread+0xd4/0xdc
[11642.222032]  [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24
[11642.223190]  [<ffffffff8147fdef>] ret_from_fork+0x3f/0x70
[11642.224394]  [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24
[11642.226295] 2 locks held by kworker/u32:3/15282:
[11642.227273]  #0:  ("%s-%s""btrfs", name){++++.+}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b
[11642.229412]  #1:  ((&work->normal_work)){+.+.+.}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b
[11642.231414] INFO: task kworker/u32:8:15289 blocked for more than 120 seconds.
[11642.232872]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.234109] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.235776] kworker/u32:8   D ffff88020de5f848     0 15289      2 0x00000000
[11642.237412] Workqueue: writeback wb_workfn (flush-btrfs-481)
[11642.238670]  ffff88020de5f848 0000000000000246 0000000000014ec0 ffff88023ed54ec0
[11642.240475]  ffff88021b1ece40 ffff88020de60000 ffff88023ed54ec0 7fffffffffffffff
[11642.242154]  0000000000000002 ffffffff8147b7f9 ffff88020de5f860 ffffffff8147b541
[11642.243715] Call Trace:
[11642.244390]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.245432]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.246392]  [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109
[11642.247479]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.248551]  [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197
[11642.249968]  [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf
[11642.251043]  [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33
[11642.252202]  [<ffffffff810b0f61>] ? ktime_get+0x41/0x52
[11642.253210]  [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102
[11642.254307]  [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102
[11642.256118]  [<ffffffff8147b814>] bit_wait_io+0x1b/0x39
[11642.257131]  [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90
[11642.258200]  [<ffffffff8111829f>] __lock_page+0x66/0x68
[11642.259168]  [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a
[11642.260516]  [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs]
[11642.261841]  [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs]
[11642.263531]  [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs]
[11642.264747]  [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs]
[11642.266148]  [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs]
[11642.267264]  [<ffffffff811236bc>] do_writepages+0x23/0x2c
[11642.268280]  [<ffffffff81192a2b>] __writeback_single_inode+0xda/0x5ba
[11642.269407]  [<ffffffff811939f0>] writeback_sb_inodes+0x27b/0x43d
[11642.270476]  [<ffffffff81193c28>] __writeback_inodes_wb+0x76/0xae
[11642.271547]  [<ffffffff81193ea6>] wb_writeback+0x19e/0x41c
[11642.272588]  [<ffffffff81194821>] wb_workfn+0x201/0x341
[11642.273523]  [<ffffffff81194821>] ? wb_workfn+0x201/0x341
[11642.274479]  [<ffffffff8106483e>] process_one_work+0x256/0x48b
[11642.275497]  [<ffffffff81064f20>] worker_thread+0x1f5/0x2a7
[11642.276518]  [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289
[11642.277520]  [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289
[11642.278517]  [<ffffffff8106a500>] kthread+0xd4/0xdc
[11642.279371]  [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24
[11642.280468]  [<ffffffff8147fdef>] ret_from_fork+0x3f/0x70
[11642.281607]  [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24
[11642.282604] 3 locks held by kworker/u32:8/15289:
[11642.283423]  #0:  ("writeback"){++++.+}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b
[11642.285629]  #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b
[11642.287538]  #2:  (&type->s_umount_key#37){+++++.}, at: [<ffffffff81171217>] trylock_super+0x1b/0x4b
[11642.289423] INFO: task fdm-stress:26848 blocked for more than 120 seconds.
[11642.290547]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.291453] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.292864] fdm-stress      D ffff88022c107c20     0 26848  26591 0x00000000
[11642.294118]  ffff88022c107c20 000000038108affa 0000000000014ec0 ffff88023ed54ec0
[11642.295602]  ffff88013ab1ca40 ffff88022c108000 ffff8800b2fc19d0 00000000000e0fff
[11642.297098]  ffff8800b2fc19b0 ffff88022c107c88 ffff88022c107c38 ffffffff8147b541
[11642.298433] Call Trace:
[11642.298896]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.299738]  [<ffffffffa045225d>] lock_extent_bits+0xfe/0x1a3 [btrfs]
[11642.300833]  [<ffffffff81082eef>] ? add_wait_queue_exclusive+0x44/0x44
[11642.301943]  [<ffffffffa0447516>] lock_and_cleanup_extent_if_need+0x68/0x18e [btrfs]
[11642.303270]  [<ffffffffa04485ba>] __btrfs_buffered_write+0x238/0x4c1 [btrfs]
[11642.304552]  [<ffffffffa044b50a>] ? btrfs_file_write_iter+0x17c/0x408 [btrfs]
[11642.305782]  [<ffffffffa044b682>] btrfs_file_write_iter+0x2f4/0x408 [btrfs]
[11642.306878]  [<ffffffff8116e298>] __vfs_write+0x7c/0xa5
[11642.307729]  [<ffffffff8116e7d1>] vfs_write+0x9d/0xe8
[11642.308602]  [<ffffffff8116efbb>] SyS_write+0x50/0x7e
[11642.309410]  [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b
[11642.310403] 3 locks held by fdm-stress/26848:
[11642.311108]  #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff811877e8>] __fdget_pos+0x3a/0x40
[11642.312578]  #1:  (sb_writers#11){.+.+.+}, at: [<ffffffff811706ee>] __sb_start_write+0x5f/0xb0
[11642.314170]  #2:  (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa044b401>] btrfs_file_write_iter+0x73/0x408 [btrfs]
[11642.316796] INFO: task fdm-stress:26849 blocked for more than 120 seconds.
[11642.317842]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.318691] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.319959] fdm-stress      D ffff8801964ffa68     0 26849  26591 0x00000000
[11642.321312]  ffff8801964ffa68 00ff8801e9975f80 0000000000014ec0 ffff88023ed94ec0
[11642.322555]  ffff8800b00b4840 ffff880196500000 ffff8801e9975f20 0000000000000002
[11642.323715]  ffff8801e9975f18 ffff8800b00b4840 ffff8801964ffa80 ffffffff8147b541
[11642.325096] Call Trace:
[11642.325532]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.326303]  [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109
[11642.327180]  [<ffffffff8108ae40>] ? mark_held_locks+0x5e/0x74
[11642.328114]  [<ffffffff8147f30e>] ? _raw_spin_unlock_irq+0x2c/0x4a
[11642.329051]  [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197
[11642.330053]  [<ffffffff8147bceb>] __wait_for_common+0x109/0x147
[11642.330952]  [<ffffffff8147bceb>] ? __wait_for_common+0x109/0x147
[11642.331869]  [<ffffffff8147e7bb>] ? usleep_range+0x4a/0x4a
[11642.332925]  [<ffffffff81074075>] ? wake_up_q+0x47/0x47
[11642.333736]  [<ffffffff8147bd4d>] wait_for_completion+0x24/0x26
[11642.334672]  [<ffffffffa044f5ce>] btrfs_wait_ordered_extents+0x1c8/0x217 [btrfs]
[11642.335858]  [<ffffffffa0465b5a>] btrfs_mksubvol+0x224/0x45d [btrfs]
[11642.336854]  [<ffffffff81082eef>] ? add_wait_queue_exclusive+0x44/0x44
[11642.337820]  [<ffffffffa0465edb>] btrfs_ioctl_snap_create_transid+0x148/0x17a [btrfs]
[11642.339026]  [<ffffffffa046603b>] btrfs_ioctl_snap_create_v2+0xc7/0x110 [btrfs]
[11642.340214]  [<ffffffffa0468582>] btrfs_ioctl+0x590/0x27bd [btrfs]
[11642.341123]  [<ffffffff8147dc00>] ? mutex_unlock+0xe/0x10
[11642.341934]  [<ffffffffa00fa6e9>] ? ext4_file_write_iter+0x2a3/0x36f [ext4]
[11642.342936]  [<ffffffff8108895d>] ? __lock_is_held+0x3c/0x57
[11642.343772]  [<ffffffff81186a1d>] ? rcu_read_unlock+0x3e/0x5d
[11642.344673]  [<ffffffff8117dc95>] do_vfs_ioctl+0x458/0x4dc
[11642.346024]  [<ffffffff81186bbe>] ? __fget_light+0x62/0x71
[11642.346873]  [<ffffffff8117dd70>] SyS_ioctl+0x57/0x79
[11642.347720]  [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b
[11642.350222] 4 locks held by fdm-stress/26849:
[11642.350898]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff811706ee>] __sb_start_write+0x5f/0xb0
[11642.352375]  #1:  (&type->i_mutex_dir_key#4/1){+.+.+.}, at: [<ffffffffa0465981>] btrfs_mksubvol+0x4b/0x45d [btrfs]
[11642.354072]  #2:  (&fs_info->subvol_sem){++++..}, at: [<ffffffffa0465a2a>] btrfs_mksubvol+0xf4/0x45d [btrfs]
[11642.355647]  #3:  (&root->ordered_extent_mutex){+.+...}, at: [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs]
[11642.357516] INFO: task fdm-stress:26850 blocked for more than 120 seconds.
[11642.358508]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.359376] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.368625] fdm-stress      D ffff88021f167688     0 26850  26591 0x00000000
[11642.369716]  ffff88021f167688 0000000000000001 0000000000014ec0 ffff88023edd4ec0
[11642.370950]  ffff880128a98680 ffff88021f168000 ffff88023edd4ec0 7fffffffffffffff
[11642.372210]  0000000000000002 ffffffff8147b7f9 ffff88021f1676a0 ffffffff8147b541
[11642.373430] Call Trace:
[11642.373853]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.374623]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.375948]  [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109
[11642.376862]  [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f
[11642.377637]  [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197
[11642.378610]  [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf
[11642.379457]  [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33
[11642.380366]  [<ffffffff810b0f61>] ? ktime_get+0x41/0x52
[11642.381353]  [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102
[11642.382255]  [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102
[11642.383162]  [<ffffffff8147b814>] bit_wait_io+0x1b/0x39
[11642.383945]  [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90
[11642.384875]  [<ffffffff8111829f>] __lock_page+0x66/0x68
[11642.385749]  [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a
[11642.386721]  [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs]
[11642.387596]  [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs]
[11642.389030]  [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs]
[11642.389973]  [<ffffffff810a25ad>] ? rcu_read_lock_sched_held+0x61/0x69
[11642.390939]  [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs]
[11642.392271]  [<ffffffffa0451c32>] ? __clear_extent_bit+0x26e/0x2c0 [btrfs]
[11642.393305]  [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs]
[11642.394239]  [<ffffffff811236bc>] do_writepages+0x23/0x2c
[11642.395045]  [<ffffffff811198c9>] __filemap_fdatawrite_range+0x5a/0x61
[11642.395991]  [<ffffffff81119946>] filemap_fdatawrite_range+0x13/0x15
[11642.397144]  [<ffffffffa044f87e>] btrfs_start_ordered_extent+0xd0/0x1a1 [btrfs]
[11642.398392]  [<ffffffffa0452094>] ? clear_extent_bit+0x17/0x19 [btrfs]
[11642.399363]  [<ffffffffa0445945>] btrfs_get_blocks_direct+0x12b/0x61c [btrfs]
[11642.400445]  [<ffffffff8119f7a1>] ? dio_bio_add_page+0x3d/0x54
[11642.401309]  [<ffffffff8119fa93>] ? submit_page_section+0x7b/0x111
[11642.402213]  [<ffffffff811a0258>] do_blockdev_direct_IO+0x685/0xc24
[11642.403139]  [<ffffffffa044581a>] ? btrfs_page_exists_in_range+0x1a1/0x1a1 [btrfs]
[11642.404360]  [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs]
[11642.406187]  [<ffffffff811a0828>] __blockdev_direct_IO+0x31/0x33
[11642.407070]  [<ffffffff811a0828>] ? __blockdev_direct_IO+0x31/0x33
[11642.407990]  [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs]
[11642.409192]  [<ffffffffa043b4ca>] btrfs_direct_IO+0x1c7/0x27e [btrfs]
[11642.410146]  [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs]
[11642.411291]  [<ffffffff81119a2c>] generic_file_read_iter+0x89/0x4e1
[11642.412263]  [<ffffffff8108ac05>] ? mark_lock+0x24/0x201
[11642.413057]  [<ffffffff8116e1f8>] __vfs_read+0x79/0x9d
[11642.413897]  [<ffffffff8116e6f1>] vfs_read+0x8f/0xd2
[11642.414708]  [<ffffffff8116ef3d>] SyS_read+0x50/0x7e
[11642.415573]  [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b
[11642.416572] 1 lock held by fdm-stress/26850:
[11642.417345]  #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff811877e8>] __fdget_pos+0x3a/0x40
[11642.418703] INFO: task fdm-stress:26851 blocked for more than 120 seconds.
[11642.419698]       Not tainted 4.4.0-rc6-btrfs-next-21+ #1
[11642.420612] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11642.421807] fdm-stress      D ffff880196483d28     0 26851  26591 0x00000000
[11642.422878]  ffff880196483d28 00ff8801c8f60740 0000000000014ec0 ffff88023ed94ec0
[11642.424149]  ffff8801c8f60740 ffff880196484000 0000000000000246 ffff8801c8f60740
[11642.425374]  ffff8801bb711840 ffff8801bb711878 ffff880196483d40 ffffffff8147b541
[11642.426591] Call Trace:
[11642.427013]  [<ffffffff8147b541>] schedule+0x82/0x9a
[11642.427856]  [<ffffffff8147b6d5>] schedule_preempt_disabled+0x18/0x24
[11642.428852]  [<ffffffff8147c23a>] mutex_lock_nested+0x1d7/0x3b4
[11642.429743]  [<ffffffffa044f456>] ? btrfs_wait_ordered_extents+0x50/0x217 [btrfs]
[11642.430911]  [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs]
[11642.432102]  [<ffffffffa044f674>] ? btrfs_wait_ordered_roots+0x57/0x191 [btrfs]
[11642.433259]  [<ffffffffa044f456>] ? btrfs_wait_ordered_extents+0x50/0x217 [btrfs]
[11642.434431]  [<ffffffffa044f6ea>] btrfs_wait_ordered_roots+0xcd/0x191 [btrfs]
[11642.436079]  [<ffffffffa0410cab>] btrfs_sync_fs+0xe0/0x1ad [btrfs]
[11642.437009]  [<ffffffff81197900>] ? SyS_tee+0x23c/0x23c
[11642.437860]  [<ffffffff81197920>] sync_fs_one_sb+0x20/0x22
[11642.438723]  [<ffffffff81171435>] iterate_supers+0x75/0xc2
[11642.439597]  [<ffffffff81197d00>] sys_sync+0x52/0x80
[11642.440454]  [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b
[11642.441533] 3 locks held by fdm-stress/26851:
[11642.442370]  #0:  (&type->s_umount_key#37){+++++.}, at: [<ffffffff8117141f>] iterate_supers+0x5f/0xc2
[11642.444043]  #1:  (&fs_info->ordered_operations_mutex){+.+...}, at: [<ffffffffa044f661>] btrfs_wait_ordered_roots+0x44/0x191 [btrfs]
[11642.446010]  #2:  (&root->ordered_extent_mutex){+.+...}, at: [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs]

This happened because under specific timings the path for direct IO reads
can deadlock with concurrent buffered writes. The diagram below shows how
this happens for an example file that has the following layout:

     [  extent A  ]  [  extent B  ]  [ ....
     0K              4K              8K

     CPU 1                                               CPU 2                             CPU 3

DIO read against range
 [0K, 8K[ starts

btrfs_direct_IO()
  --> calls btrfs_get_blocks_direct()
      which finds the extent map for the
      extent A and leaves the range
      [0K, 4K[ locked in the inode's
      io tree

                                                   buffered write against
                                                   range [4K, 8K[ starts

                                                   __btrfs_buffered_write()
                                                     --> dirties page at 4K

                                                                                     a user space
                                                                                     task calls sync
                                                                                     for e.g or
                                                                                     writepages() is
                                                                                     invoked by mm

                                                                                     writepages()
                                                                                       run_delalloc_range()
                                                                                         cow_file_range()
                                                                                           --> ordered extent X
                                                                                               for the buffered
                                                                                               write is created
                                                                                               and
                                                                                               writeback starts

  --> calls btrfs_get_blocks_direct()
      again, without submitting first
      a bio for reading extent A, and
      finds the extent map for extent B

  --> calls lock_extent_direct()

      --> locks range [4K, 8K[
      --> finds ordered extent X
          covering range [4K, 8K[
      --> unlocks range [4K, 8K[

                                                  buffered write against
                                                  range [0K, 8K[ starts

                                                  __btrfs_buffered_write()
                                                    prepare_pages()
                                                      --> locks pages with
                                                          offsets 0 and 4K
                                                    lock_and_cleanup_extent_if_need()
                                                      --> blocks attempting to
                                                          lock range [0K, 8K[ in
                                                          the inode's io tree,
                                                          because the range [0, 4K[
                                                          is already locked by the
                                                          direct IO task at CPU 1

      --> calls
          btrfs_start_ordered_extent(oe X)

          btrfs_start_ordered_extent(oe X)

            --> At this point writeback for ordered
                extent X has not finished yet

            filemap_fdatawrite_range()
              btrfs_writepages()
                extent_writepages()
                  extent_write_cache_pages()
                    --> finds page with offset 0
                        with the writeback tag
                        (and not dirty)
                    --> tries to lock it
                         --> deadlock, task at CPU 2
                             has the page locked and
                             is blocked on the io range
                             [0, 4K[ that was locked
                             earlier by this task

So fix this by falling back to a buffered read in the direct IO read path
when an ordered extent for a buffered write is found.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:37 -08:00
Filipe Manana
f4dfe68710 Btrfs: fix extent_same allowing destination offset beyond i_size
When using the same file as the source and destination for a dedup
(extent_same ioctl) operation we were allowing it to dedup to a
destination offset beyond the file's size, which doesn't make sense and
it's not allowed for the case where the source and destination files are
not the same file. This made de deduplication operation successful only
when the source range corresponded to a hole, a prealloc extent or an
extent with all bytes having a value of 0x00. This was also leaving a
file hole (between i_size and destination offset) without the
corresponding file extent items, which can be reproduced with the
following steps for example:

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

  $ xfs_io -f -c "pwrite -S 0xab 304457 404990" /mnt/sdi/foobar
  wrote 404990/404990 bytes at offset 304457
  395 KiB, 99 ops; 0.0000 sec (31.150 MiB/sec and 7984.5149 ops/sec)

  $ /git/hub/duperemove/btrfs-extent-same 24576 /mnt/sdi/foobar 28672 /mnt/sdi/foobar 929792
  Deduping 2 total files
  (28672, 24576): /mnt/sdi/foobar
  (929792, 24576): /mnt/sdi/foobar
  1 files asked to be deduped
  i: 0, status: 0, bytes_deduped: 24576
  24576 total bytes deduped in this operation

  $ umount /mnt/sdi
  $ btrfsck /dev/sdi
  Checking filesystem on /dev/sdi
  UUID: 98c528aa-0833-427d-9403-b98032ffbf9d
  checking extents
  checking free space cache
  checking fs roots
  root 5 inode 257 errors 100, file extent discount
  Found file extent holes:
          start: 712704, len: 217088
  found 540673 bytes used err is 1
  total csum bytes: 400
  total tree bytes: 131072
  total fs tree bytes: 32768
  total extent tree bytes: 16384
  btree space waste bytes: 123675
  file data blocks allocated: 671744
    referenced 671744
  btrfs-progs v4.2.3

So fix this by not allowing the destination to go beyond the file's size,
just as we do for the same where the source and destination files are not
the same.

A test for xfstests follows.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:33 -08:00
Filipe Manana
2be63d5ce9 Btrfs: fix file loss on log replay after renaming a file and fsync
We have two cases where we end up deleting a file at log replay time
when we should not. For this to happen the file must have been renamed
and a directory inode must have been fsynced/logged.

Two examples that exercise these two cases are listed below.

  Case 1)

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ mkdir -p /mnt/a/b
  $ mkdir /mnt/c
  $ touch /mnt/a/b/foo
  $ sync
  $ mv /mnt/a/b/foo /mnt/c/
  # Create file bar just to make sure the fsync on directory a/ does
  # something and it's not a no-op.
  $ touch /mnt/a/bar
  $ xfs_io -c "fsync" /mnt/a
  < power fail / crash >

  The next time the filesystem is mounted, the log replay procedure
  deletes file foo.

  Case 2)

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ mkdir /mnt/a
  $ mkdir /mnt/b
  $ mkdir /mnt/c
  $ touch /mnt/a/foo
  $ ln /mnt/a/foo /mnt/b/foo_link
  $ touch /mnt/b/bar
  $ sync
  $ unlink /mnt/b/foo_link
  $ mv /mnt/b/bar /mnt/c/
  $ xfs_io -c "fsync" /mnt/a/foo
  < power fail / crash >

  The next time the filesystem is mounted, the log replay procedure
  deletes file bar.

The reason why the files are deleted is because when we log inodes
other then the fsync target inode, we ignore their last_unlink_trans
value and leave the log without enough information to later replay the
rename operations. So we need to look at the last_unlink_trans values
and fallback to a transaction commit if they are greater than the
id of the last committed transaction.

So fix this by looking at the last_unlink_trans values and fallback to
transaction commits when needed. Also, when logging other inodes (for
case 1 we logged descendants of the fsync target inode while for case 2
we logged ascendants) we need to care about concurrent tasks updating
the last_unlink_trans of inodes we are logging (which was already an
existing problem in check_parent_dirs_for_sync()). Since we can not
acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes
deadlocks with other concurrent operations that acquire the i_mutex of
2 inodes (other fsyncs or renames for example), we need to serialize on
the log_mutex of the inode we are logging. A task setting a new value for
an inode's last_unlink_trans must acquire the inode's log_mutex and it
must do this update before doing the actual unlink operation (which is
already the case except when deleting a snapshot). Conversely the task
logging the inode must first log the inode and then check the inode's
last_unlink_trans value while holding its log_mutex, as if its value is
not greater then the id of the last committed transaction it means it
logged a safe state of the inode's items, while if its value is not
smaller then the id of the last committed transaction it means the inode
state it has logged might not be safe (the concurrent task might have
just updated last_unlink_trans but hasn't done yet the unlink operation)
and therefore a transaction commit must be done.

Test cases for xfstests follow in separate patches.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:29 -08:00
Filipe Manana
1ec9a1ae1e Btrfs: fix unreplayable log after snapshot delete + parent dir fsync
If we delete a snapshot, fsync its parent directory and crash/power fail
before the next transaction commit, on the next mount when we attempt to
replay the log tree of the root containing the parent directory we will
fail and prevent the filesystem from mounting, which is solvable by wiping
out the log trees with the btrfs-zero-log tool but very inconvenient as
we will lose any data and metadata fsynced before the parent directory
was fsynced.

For example:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt
  $ mkdir /mnt/testdir
  $ btrfs subvolume snapshot /mnt /mnt/testdir/snap
  $ btrfs subvolume delete /mnt/testdir/snap
  $ xfs_io -c "fsync" /mnt/testdir
  < crash / power failure and reboot >
  $ mount /dev/sdc /mnt
  mount: mount(2) failed: No such file or directory

And in dmesg/syslog we get the following message and trace:

[192066.361162] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257
[192066.363010] ------------[ cut here ]------------
[192066.365268] WARNING: CPU: 4 PID: 5130 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x17a/0x354 [btrfs]()
[192066.367250] BTRFS: Transaction aborted (error -2)
[192066.368401] Modules linked in: btrfs dm_flakey dm_mod ppdev sha256_generic xor raid6_pq hmac drbg ansi_cprng aesni_intel acpi_cpufreq tpm_tis aes_x86_64 tpm ablk_helper evdev cryptd sg parport_pc i2c_piix4 psmouse lrw parport i2c_core pcspkr gf128mul processor serio_raw glue_helper button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs]
[192066.377154] CPU: 4 PID: 5130 Comm: mount Tainted: G        W       4.4.0-rc6-btrfs-next-20+ #1
[192066.378875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[192066.380889]  0000000000000000 ffff880143923670 ffffffff81257570 ffff8801439236b8
[192066.382561]  ffff8801439236a8 ffffffff8104ec07 ffffffffa039dc2c 00000000fffffffe
[192066.384191]  ffff8801ed31d000 ffff8801b9fc9c88 ffff8801086875e0 ffff880143923710
[192066.385827] Call Trace:
[192066.386373]  [<ffffffff81257570>] dump_stack+0x4e/0x79
[192066.387387]  [<ffffffff8104ec07>] warn_slowpath_common+0x99/0xb2
[192066.388429]  [<ffffffffa039dc2c>] ? __btrfs_unlink_inode+0x17a/0x354 [btrfs]
[192066.389236]  [<ffffffff8104ec68>] warn_slowpath_fmt+0x48/0x50
[192066.389884]  [<ffffffffa039dc2c>] __btrfs_unlink_inode+0x17a/0x354 [btrfs]
[192066.390621]  [<ffffffff81184b55>] ? iput+0xb0/0x266
[192066.391200]  [<ffffffffa039ea25>] btrfs_unlink_inode+0x1c/0x3d [btrfs]
[192066.391930]  [<ffffffffa03ca623>] check_item_in_log+0x1fe/0x29b [btrfs]
[192066.392715]  [<ffffffffa03ca827>] replay_dir_deletes+0x167/0x1cf [btrfs]
[192066.393510]  [<ffffffffa03cccc7>] replay_one_buffer+0x417/0x570 [btrfs]
[192066.394241]  [<ffffffffa03ca164>] walk_up_log_tree+0x10e/0x1dc [btrfs]
[192066.394958]  [<ffffffffa03cac72>] walk_log_tree+0xa5/0x190 [btrfs]
[192066.395628]  [<ffffffffa03ce8b8>] btrfs_recover_log_trees+0x239/0x32c [btrfs]
[192066.396790]  [<ffffffffa03cc8b0>] ? replay_one_extent+0x50a/0x50a [btrfs]
[192066.397891]  [<ffffffffa0394041>] open_ctree+0x1d8b/0x2167 [btrfs]
[192066.398897]  [<ffffffffa03706e1>] btrfs_mount+0x5ef/0x729 [btrfs]
[192066.399823]  [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf
[192066.400739]  [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3
[192066.401700]  [<ffffffff811714b9>] mount_fs+0x67/0x131
[192066.402482]  [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde
[192066.403930]  [<ffffffffa03702bd>] btrfs_mount+0x1cb/0x729 [btrfs]
[192066.404831]  [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf
[192066.405726]  [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3
[192066.406621]  [<ffffffff811714b9>] mount_fs+0x67/0x131
[192066.407401]  [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde
[192066.408247]  [<ffffffff8118ae36>] do_mount+0x893/0x9d2
[192066.409047]  [<ffffffff8113009b>] ? strndup_user+0x3f/0x8c
[192066.409842]  [<ffffffff8118b187>] SyS_mount+0x75/0xa1
[192066.410621]  [<ffffffff8147e517>] entry_SYSCALL_64_fastpath+0x12/0x6b
[192066.411572] ---[ end trace 2de42126c1e0a0f0 ]---
[192066.412344] BTRFS: error (device dm-0) in __btrfs_unlink_inode:3986: errno=-2 No such entry
[192066.413748] BTRFS: error (device dm-0) in btrfs_replay_log:2464: errno=-2 No such entry (Failed to recover log tree)
[192066.415458] BTRFS error (device dm-0): cleaner transaction attach returned -30
[192066.444613] BTRFS: open_ctree failed

This happens because when we are replaying the log and processing the
directory entry pointing to the snapshot in the subvolume tree, we treat
its btrfs_dir_item item as having a location with a key type matching
BTRFS_INODE_ITEM_KEY, which is wrong because the type matches
BTRFS_ROOT_ITEM_KEY and therefore must be processed differently, as the
object id refers to a root number and not to an inode in the root
containing the parent directory.

So fix this by triggering a transaction commit if an fsync against the
parent directory is requested after deleting a snapshot. This is the
simplest approach for a rare use case. Some alternative that avoids the
transaction commit would require more code to explicitly delete the
snapshot at log replay time (factoring out common code from ioctl.c:
btrfs_ioctl_snap_destroy()), special care at fsync time to remove the
log tree of the snapshot's root from the log root of the root of tree
roots, amongst other steps.

A test case for xfstests that triggers the issue follows.

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"
  tmp=/tmp/$$
  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
      _cleanup_flakey
      cd /
      rm -f $tmp.*
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter
  . ./common/dmflakey

  # real QA test starts here
  _need_to_be_root
  _supported_fs btrfs
  _supported_os Linux
  _require_scratch
  _require_dm_target flakey
  _require_metadata_journaling $SCRATCH_DEV

  rm -f $seqres.full

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

  # Create a snapshot at the root of our filesystem (mount point path), delete it,
  # fsync the mount point path, crash and mount to replay the log. This should
  # succeed and after the filesystem is mounted the snapshot should not be visible
  # anymore.
  _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap1
  _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT
  _flakey_drop_and_remount
  [ -e $SCRATCH_MNT/snap1 ] && \
      echo "Snapshot snap1 still exists after log replay"

  # Similar scenario as above, but this time the snapshot is created inside a
  # directory and not directly under the root (mount point path).
  mkdir $SCRATCH_MNT/testdir
  _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/testdir/snap2
  _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/testdir/snap2
  $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir
  _flakey_drop_and_remount
  [ -e $SCRATCH_MNT/testdir/snap2 ] && \
      echo "Snapshot snap2 still exists after log replay"

  _unmount_flakey

  echo "Silence is golden"
  status=0
  exit

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-03-01 08:23:25 -08:00
Chris Mason
c05c5ee5ea Btrfs patchsets for 4.6
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Merge tag 'for-chris' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.6

Btrfs patchsets for 4.6
2016-03-01 08:13:56 -08:00
David Sterba
f5bc27c71a Merge branch 'dev/control-ioctl' into for-chris-4.6 2016-02-26 15:38:34 +01:00
David Sterba
fa695b01bc Merge branch 'misc-4.6' into for-chris-4.6
# Conflicts:
#	fs/btrfs/file.c
2016-02-26 15:38:34 +01:00
David Sterba
f004fae0cf Merge branch 'cleanups-4.6' into for-chris-4.6 2016-02-26 15:38:33 +01:00
David Sterba
675d276b32 Merge branch 'foreign/liubo/replace-lockup' into for-chris-4.6 2016-02-26 15:38:32 +01:00
David Sterba
e9ddd77a31 Merge branch 'foreign/josef/space-updates' into for-chris-4.6 2016-02-26 15:38:31 +01:00
David Sterba
ff7db6e05a Merge branch 'foreign/zhaolei/reada' into for-chris-4.6 2016-02-26 15:38:30 +01:00
David Sterba
23c1a966f2 Merge branch 'foreign/qu/norecovery-v7' into for-chris-4.6 2016-02-26 15:38:30 +01:00
David Sterba
67d605fec1 Merge branch 'dev/rename-keys' into for-chris-4.6 2016-02-26 15:38:29 +01:00
David Sterba
e22b3d1fbe Merge branch 'dev/gfp-flags' into for-chris-4.6 2016-02-26 15:38:28 +01:00
David Sterba
5f1b5664d9 Merge branch 'chandan/prep-subpage-blocksize' into for-chris-4.6
# Conflicts:
#	fs/btrfs/file.c
2016-02-26 15:38:28 +01:00
Liu Bo
73beece9ca Btrfs: fix lockdep deadlock warning due to dev_replace
Xfstests btrfs/011 complains about a deadlock warning,

[ 1226.649039] =========================================================
[ 1226.649039] [ INFO: possible irq lock inversion dependency detected ]
[ 1226.649039] 4.1.0+ #270 Not tainted
[ 1226.649039] ---------------------------------------------------------
[ 1226.652955] kswapd0/46 just changed the state of lock:
[ 1226.652955]  (&delayed_node->mutex){+.+.-.}, at: [<ffffffff81458735>] __btrfs_release_delayed_node+0x45/0x1d0
[ 1226.652955] but this lock took another, RECLAIM_FS-unsafe lock in the past:
[ 1226.652955]  (&fs_info->dev_replace.lock){+.+.+.}

and interrupts could create inverse lock ordering between them.

[ 1226.652955]
other info that might help us debug this:
[ 1226.652955] Chain exists of:
  &delayed_node->mutex --> &found->groups_sem --> &fs_info->dev_replace.lock

[ 1226.652955]  Possible interrupt unsafe locking scenario:

[ 1226.652955]        CPU0                    CPU1
[ 1226.652955]        ----                    ----
[ 1226.652955]   lock(&fs_info->dev_replace.lock);
[ 1226.652955]                                local_irq_disable();
[ 1226.652955]                                lock(&delayed_node->mutex);
[ 1226.652955]                                lock(&found->groups_sem);
[ 1226.652955]   <Interrupt>
[ 1226.652955]     lock(&delayed_node->mutex);
[ 1226.652955]
 *** DEADLOCK ***

Commit 084b6e7c76 ("btrfs: Fix a lockdep warning when running xfstest.") tried
to fix a similar one that has the exactly same warning, but with that, we still
run to this.

The above lock chain comes from
btrfs_commit_transaction
  ->btrfs_run_delayed_items
    ...
    ->__btrfs_update_delayed_inode
      ...
      ->__btrfs_cow_block
         ...
         ->find_free_extent
            ->cache_block_group
              ->load_free_space_cache
                ->btrfs_readpages
                  ->submit_one_bio
                    ...
                    ->__btrfs_map_block
                      ->btrfs_dev_replace_lock

However, with high memory pressure, tasks which hold dev_replace.lock can
be interrupted by kswapd and then kswapd is intended to release memory occupied
by superblock, inodes and dentries, where we may call evict_inode, and it comes
to

[ 1226.652955]  [<ffffffff81458735>] __btrfs_release_delayed_node+0x45/0x1d0
[ 1226.652955]  [<ffffffff81459e74>] btrfs_remove_delayed_node+0x24/0x30
[ 1226.652955]  [<ffffffff8140c5fe>] btrfs_evict_inode+0x34e/0x700

delayed_node->mutex may be acquired in __btrfs_release_delayed_node(), and it leads
to a ABBA deadlock.

To fix this, we can use "blocking rwlock" used in the case of extent_buffer, but
things are simpler here since we only needs read's spinlock to blocking lock.

With this, btrfs/011 no more produces warnings in dmesg.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 13:10:10 +01:00
David Sterba
d5131b658c btrfs: drop unused argument in btrfs_ioctl_get_supported_features
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 12:56:35 +01:00
David Sterba
c5868f8362 btrfs: add GET_SUPPORTED_FEATURES to the control device ioctls
The control device is accessible when no filesystem is mounted and we
may want to query features supported by the module. This is already
possible using the sysfs files, this ioctl is for parity and
convenience.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 12:56:21 +01:00
David Sterba
f7e98a7fff btrfs: change max_inline default to 2048
The current practical default is ~4k on x86_64 (the logic is more complex,
simplified for brevity), the inlined files land in the metadata group and
thus consume space that could be needed for the real metadata.

The inlining brings some usability surprises:

1) total space consumption measured on various filesystems and btrfs
   with DUP metadata was quite visible because of the duplicated data
   within metadata

2) inlined data may exhaust the metadata, which are more precious in case
   the entire device space is allocated to chunks (ie. balance cannot
   make the space more compact)

3) performance suffers a bit as the inlined blocks are duplicate and
   stored far away on the device.

Proposed fix: set the default to 2048

This fixes namely 1), the total filesysystem space consumption will be on
par with other filesystems.

Partially fixes 2), more data are pushed to the data block groups.

The characteristics of 3) are based on actual small file size
distribution.

The change is independent of the metadata blockgroup type (though it's
most visible with DUP) or system page size as these parameters are not
trival to find out, compared to file size.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 12:55:27 +01:00
David Sterba
11ea474f74 btrfs: remove error message from search ioctl for nonexistent tree
Let's remove the error message that appears when the tree_id is not
present. This can happen with the quota tree and has been observed in
practice. The applications are supposed to handle -ENOENT and we don't
need to report that in the system log as it's not a fatal error.

Reported-by: Vlastimil Babka <vbabka@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 12:54:48 +01:00
Arnd Bergmann
f827ba9a64 btrfs: avoid uninitialized variable warning
With CONFIG_SMP and CONFIG_PREEMPT both disabled, gcc decides
to partially inline the get_state_failrec() function but cannot
figure out that means the failrec pointer is always valid
if the function returns success, which causes a harmless
warning:

fs/btrfs/extent_io.c: In function 'clean_io_failure':
fs/btrfs/extent_io.c:2131:4: error: 'failrec' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This marks get_state_failrec() and set_state_failrec() both
as 'noinline', which avoids the warning in all cases for me,
and seems less ugly than adding a fake initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 47dc196ae7 ("btrfs: use proper type for failrec in extent_state")
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-23 12:42:46 +01:00
Linus Torvalds
ce6b71432d Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "My for-linus-4.5 branch has a btrfs DIO error passing fix.

  I know how much you love DIO, so I'm going to suggest against reading
  it.  We'll follow up with a patch to drop the error arg from
  dio_end_io in the next merge window."

* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix direct IO requests not reporting IO error to user space
2016-02-19 13:40:42 -08:00
Kinglong Mee
aa66b0bb08 btrfs: fix memory leak of fs_info in block group cache
When starting up linux with btrfs filesystem, I got many memory leak
messages by kmemleak as,

unreferenced object 0xffff880066882000 (size 4096):
  comm "modprobe", pid 730, jiffies 4294690024 (age 196.599s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8174d52e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811d09aa>] kmem_cache_alloc_trace+0xea/0x1e0
    [<ffffffffa03620fb>] btrfs_alloc_dummy_fs_info+0x6b/0x2a0 [btrfs]
    [<ffffffffa03624fc>] btrfs_alloc_dummy_block_group+0x5c/0x120 [btrfs]
    [<ffffffffa0360aa9>] btrfs_test_free_space_cache+0x39/0xed0 [btrfs]
    [<ffffffffa03b5a74>] trace_raw_output_xfs_attr_class+0x54/0xe0 [xfs]
    [<ffffffff81002122>] do_one_initcall+0xb2/0x1f0
    [<ffffffff811765aa>] do_init_module+0x5e/0x1e9
    [<ffffffff810fec09>] load_module+0x20a9/0x2690
    [<ffffffff810ff439>] SyS_finit_module+0xb9/0xf0
    [<ffffffff81757daf>] entry_SYSCALL_64_fastpath+0x12/0x76
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff8800573f8000 (size 10256):
  comm "modprobe", pid 730, jiffies 4294690185 (age 196.460s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8174d52e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff8119ca6e>] kmalloc_order+0x5e/0x70
    [<ffffffff8119caa4>] kmalloc_order_trace+0x24/0x90
    [<ffffffffa03620b3>] btrfs_alloc_dummy_fs_info+0x23/0x2a0 [btrfs]
    [<ffffffffa03624fc>] btrfs_alloc_dummy_block_group+0x5c/0x120 [btrfs]
    [<ffffffffa036603d>] run_test+0xfd/0x320 [btrfs]
    [<ffffffffa0366f34>] btrfs_test_free_space_tree+0x94/0xee [btrfs]
    [<ffffffffa03b5aab>] trace_raw_output_xfs_attr_class+0x8b/0xe0 [xfs]
    [<ffffffff81002122>] do_one_initcall+0xb2/0x1f0
    [<ffffffff811765aa>] do_init_module+0x5e/0x1e9
    [<ffffffff810fec09>] load_module+0x20a9/0x2690
    [<ffffffff810ff439>] SyS_finit_module+0xb9/0xf0
    [<ffffffff81757daf>] entry_SYSCALL_64_fastpath+0x12/0x76
    [<ffffffffffffffff>] 0xffffffffffffffff

This patch lets btrfs using fs_info stored in btrfs_root for
block group cache directly without allocating a new one.

Fixes: d0bd456074 ("Btrfs: add fragment=* debug mount option")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 13:28:24 +01:00
Zhao Lei
4da2e26a2a btrfs: Continue write in case of can_not_nocow
btrfs failed in xfstests btrfs/080 with -o nodatacow.

Can be reproduced by following script:
  DEV=/dev/vdg
  MNT=/mnt/tmp

  umount $DEV &>/dev/null
  mkfs.btrfs -f $DEV
  mount -o nodatacow $DEV $MNT

  dd if=/dev/zero of=$MNT/test bs=1 count=2048 &
  btrfs subvolume snapshot -r $MNT $MNT/test_snap &
  wait
  --
  We can see dd failed on NO_SPACE.

Reason:
  __btrfs_buffered_write should run cow write when no_cow impossible,
  and current code is designed with above logic.
  But check_can_nocow() have 2 type of return value(0 and <0) on
  can_not_no_cow, and current code only continue write on first case,
  the second case happened in doing subvolume.

Fix:
  Continue write when check_can_nocow() return 0 and <0.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
2016-02-18 13:18:06 +01:00
Kinglong Mee
5598e9005a btrfs: drop null testing before destroy functions
Cleanup.

kmem_cache_destroy has support NULL argument checking,
so drop the double null testing before calling it.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:46:03 +01:00
Sudip Mukherjee
89771cc98c btrfs: fix build warning
We were getting build warning about:
fs/btrfs/extent-tree.c:7021:34: warning: ‘used_bg’ may be used
	uninitialized in this function

It is not a valid warning as used_bg is never used uninitilized since
locked is initially false so we can never be in the section where
'used_bg' is used. But gcc is not able to understand that and we can
initialize it while declaring to silence the warning.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:46:03 +01:00
David Sterba
47dc196ae7 btrfs: use proper type for failrec in extent_state
We use the private member of extent_state to store the failrec and play
pointless pointer games.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:46:03 +01:00
Deepa Dinamani
04b285f35e btrfs: Replace CURRENT_TIME by current_fs_time()
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_fs_time() instead.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:46:03 +01:00
Dave Jones
8f682f6955 btrfs: remove open-coded swap() in backref.c:__merge_refs
The kernel provides a swap() that does the same thing as this code.

Signed-off-by: Dave Jones <dsj@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:45:55 +01:00
Byongho Lee
ac1407ba24 btrfs: remove redundant error check
While running btrfs_mksubvol(), d_really_is_positive() is called twice.
First in btrfs_mksubvol() and second inside btrfs_may_create().  So I
remove the first one.

Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:35:27 +01:00
Byongho Lee
0138b6fe8f btrfs: simplify expression in btrfs_calc_trans_metadata_size()
Simplify expression in btrfs_calc_trans_metadata_size().

Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
Reviewed-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:33:17 +01:00
Josef Bacik
baee879064 Btrfs: check reserved when deciding to background flush
We will sometimes start background flushing the various enospc related things
(delayed nodes, delalloc, etc) if we are getting close to reserving all of our
available space.  We don't want to do this however when we are actually using
this space as it causes unneeded thrashing.  We currently try to do this by
checking bytes_used >= thresh, but bytes_used is only part of the equation, we
need to use bytes_reserved as well as this represents space that is very likely
to become bytes_used in the future.

My tracing tool will keep count of the number of times we kick off the async
flusher, the following are counts for the entire run of generic/027

		No Patch	Patch
avg: 		5385		5009
median:		5500		4916

We skewed lower than the average with my patch and higher than the average with
the patch, overall it cuts the flushing from anywhere from 5-10%, which in the
case of actual ENOSPC is quite helpful.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:29:43 +01:00
Josef Bacik
88d3a5aaf6 Btrfs: add transaction space reservation tracepoints
There are a few places where we add to trans->bytes_reserved but don't have the
corresponding trace point.  With these added my tool no longer sees transaction
leaks.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:22:41 +01:00
Josef Bacik
dc95f7bfc5 Btrfs: fix truncate_space_check
truncate_space_check is using btrfs_csum_bytes_to_leaves() but forgetting to
multiply by nodesize so we get an actual byte count.  We need a tracepoint here
so that we have the matching reserve for the release that will come later.  Also
add a comment to make clear what the intent of truncate_space_check is.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:22:24 +01:00
Josef Bacik
fb4b10e5d5 Btrfs: change how we update the global block rsv
I'm writing a tool to visualize the enospc system in order to help debug enospc
bugs and I found weird data and ran it down to when we update the global block
rsv.  We add all of the remaining free space to the block rsv, do a trace event,
then remove the extra and do another trace event.  This makes my visualization
look silly and is unintuitive code as well.  Fix this stuff to only add the
amount we are missing, or free the amount we are missing.  This is less clean to
read but more explicit in what it is doing, as well as only emitting events for
values that make sense.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 11:21:48 +01:00
Zhao Lei
7aff8cf4a6 btrfs: reada: ignore creating reada_extent for a non-existent device
For a non-existent device, old code bypasses adding it in dev's reada
queue.

And to solve problem of unfinished waitting in raid5/6,
commit 5fbc7c59fd ("Btrfs: fix unfinished readahead thread for
raid5/6 degraded mounting")
adding an exception for the first stripe, in short, the first
stripe will always be processed whether the device exists or not.

Actually we have a better way for the above request: just bypass
creation of the reada_extent for non-existent device, it will make
code simple and effective.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18 10:27:23 +01:00