When removing a directory we are not updating its last_unlink_trans field,
which can result in incorrect fsync behaviour in case some one fsyncs the
directory after it was removed because it's holding a file descriptor on
it.
Example scenario:
mkdir /mnt/dir1
mkdir /mnt/dir1/dir2
mkdir /mnt/dir3
sync -f /mnt
# Do some change to the directory and fsync it.
chmod 700 /mnt/dir1
xfs_io -c fsync /mnt/dir1
# Move dir2 out of dir1 so that dir1 becomes empty.
mv /mnt/dir1/dir2 /mnt/dir3/
open fd on /mnt/dir1
call rmdir(2) on path "/mnt/dir1"
fsync fd
<trigger power failure>
When attempting to mount the filesystem, the log replay will fail with
an -EIO error and dmesg/syslog has the following:
[445771.626482] BTRFS info (device dm-0): first mount of filesystem
0368bbea-6c5e-44b5-b409-
09abe496e650
[445771.626486] BTRFS info (device dm-0): using crc32c checksum algorithm
[445771.627912] BTRFS info (device dm-0): start tree-log replay
[445771.628335] page: refcount:2 mapcount:0 mapping:
0000000061443ddc index:0x1d00 pfn:0x7072a5
[445771.629453] memcg:
ffff89f400351b00
[445771.629892] aops:btree_aops [btrfs] ino:1
[445771.630737] flags: 0x17fffc00000402a(uptodate|lru|private|writeback|node=0|zone=2|lastcpupid=0x1ffff)
[445771.632359] raw:
017fffc00000402a fffff47284d950c8 fffff472907b7c08 ffff89f458e412b8
[445771.633713] raw:
0000000000001d00 ffff89f6c51d1a90 00000002ffffffff ffff89f400351b00
[445771.635029] page dumped because: eb page dump
[445771.635825] BTRFS critical (device dm-0): corrupt leaf: root=5 block=
30408704 slot=10 ino=258, invalid nlink: has 2 expect no more than 1 for dir
[445771.638088] BTRFS info (device dm-0): leaf
30408704 gen 10 total ptrs 17 free space 14878 owner 5
[445771.638091] BTRFS info (device dm-0): refs 4 lock_owner 0 current
3581087
[445771.638094] item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
[445771.638097] inode generation 3 transid 9 size 16 nbytes 16384
[445771.638098] block group 0 mode 40755 links 1 uid 0 gid 0
[445771.638100] rdev 0 sequence 2 flags 0x0
[445771.638102] atime
1775744884.0
[445771.660056] ctime
1775744885.
645502983
[445771.660058] mtime
1775744885.
645502983
[445771.660060] otime
1775744884.0
[445771.660062] item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12
[445771.660064] index 0 name_len 2
[445771.660066] item 2 key (256 DIR_ITEM
1843588421) itemoff 16077 itemsize 34
[445771.660068] location key (259 1 0) type 2
[445771.660070] transid 9 data_len 0 name_len 4
[445771.660075] item 3 key (256 DIR_ITEM
2363071922) itemoff 16043 itemsize 34
[445771.660076] location key (257 1 0) type 2
[445771.660077] transid 9 data_len 0 name_len 4
[445771.660078] item 4 key (256 DIR_INDEX 2) itemoff 16009 itemsize 34
[445771.660079] location key (257 1 0) type 2
[445771.660080] transid 9 data_len 0 name_len 4
[445771.660081] item 5 key (256 DIR_INDEX 3) itemoff 15975 itemsize 34
[445771.660082] location key (259 1 0) type 2
[445771.660083] transid 9 data_len 0 name_len 4
[445771.660084] item 6 key (257 INODE_ITEM 0) itemoff 15815 itemsize 160
[445771.660086] inode generation 9 transid 9 size 8 nbytes 0
[445771.660087] block group 0 mode 40777 links 1 uid 0 gid 0
[445771.660088] rdev 0 sequence 2 flags 0x0
[445771.660089] atime
1775744885.
641174097
[445771.660090] ctime
1775744885.
645502983
[445771.660091] mtime
1775744885.
645502983
[445771.660105] otime
1775744885.
641174097
[445771.660106] item 7 key (257 INODE_REF 256) itemoff 15801 itemsize 14
[445771.660107] index 2 name_len 4
[445771.660108] item 8 key (257 DIR_ITEM
2676584006) itemoff 15767 itemsize 34
[445771.660109] location key (258 1 0) type 2
[445771.660110] transid 9 data_len 0 name_len 4
[445771.660111] item 9 key (257 DIR_INDEX 2) itemoff 15733 itemsize 34
[445771.660112] location key (258 1 0) type 2
[445771.660113] transid 9 data_len 0 name_len 4
[445771.660114] item 10 key (258 INODE_ITEM 0) itemoff 15573 itemsize 160
[445771.660115] inode generation 9 transid 10 size 0 nbytes 0
[445771.660116] block group 0 mode 40755 links 2 uid 0 gid 0
[445771.660117] rdev 0 sequence 0 flags 0x0
[445771.660118] atime
1775744885.
645502983
[445771.660119] ctime
1775744885.
645502983
[445771.660120] mtime
1775744885.
645502983
[445771.660121] otime
1775744885.
645502983
[445771.660122] item 11 key (258 INODE_REF 257) itemoff 15559 itemsize 14
[445771.660123] index 2 name_len 4
[445771.660124] item 12 key (258 INODE_REF 259) itemoff 15545 itemsize 14
[445771.660125] index 2 name_len 4
[445771.660126] item 13 key (259 INODE_ITEM 0) itemoff 15385 itemsize 160
[445771.660127] inode generation 9 transid 10 size 8 nbytes 0
[445771.660128] block group 0 mode 40755 links 1 uid 0 gid 0
[445771.660129] rdev 0 sequence 1 flags 0x0
[445771.660130] atime
1775744885.
645502983
[445771.660130] ctime
1775744885.
645502983
[445771.660131] mtime
1775744885.
645502983
[445771.660132] otime
1775744885.
645502983
[445771.660133] item 14 key (259 INODE_REF 256) itemoff 15371 itemsize 14
[445771.660134] index 3 name_len 4
[445771.660135] item 15 key (259 DIR_ITEM
2676584006) itemoff 15337 itemsize 34
[445771.660136] location key (258 1 0) type 2
[445771.660137] transid 10 data_len 0 name_len 4
[445771.660138] item 16 key (259 DIR_INDEX 2) itemoff 15303 itemsize 34
[445771.660139] location key (258 1 0) type 2
[445771.660140] transid 10 data_len 0 name_len 4
[445771.660144] BTRFS error (device dm-0): block=
30408704 write time tree block corruption detected
[445771.661650] ------------[ cut here ]------------
[445771.662358] WARNING: fs/btrfs/disk-io.c:326 at btree_csum_one_bio+0x217/0x230 [btrfs], CPU#8: mount/
3581087
[445771.663588] Modules linked in: btrfs f2fs xfs (...)
[445771.671229] CPU: 8 UID: 0 PID:
3581087 Comm: mount Tainted: G W 7.0.0-rc6-btrfs-next-230+ #2 PREEMPT(full)
[445771.672575] Tainted: [W]=WARN
[445771.672987] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[445771.674460] RIP: 0010:btree_csum_one_bio+0x217/0x230 [btrfs]
[445771.675222] Code: 89 44 24 (...)
[445771.677364] RSP: 0018:
ffffd23882247660 EFLAGS:
00010246
[445771.678029] RAX:
0000000000000000 RBX:
ffff89f6c51d1a90 RCX:
0000000000000000
[445771.678975] RDX:
0000000000000000 RSI:
0000000000000001 RDI:
ffff89f406020000
[445771.679983] RBP:
ffff89f821204000 R08:
0000000000000000 R09:
00000000ffefffff
[445771.680905] R10:
ffffd23882247448 R11:
0000000000000003 R12:
ffffd23882247668
[445771.681978] R13:
ffff89f458e40fc0 R14:
ffff89f737f4f500 R15:
ffff89f737f4f500
[445771.682912] FS:
00007f0447a98840(0000) GS:
ffff89fb9771d000(0000) knlGS:
0000000000000000
[445771.684393] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[445771.685230] CR2:
00007f0447bf1330 CR3:
000000017cb02002 CR4:
0000000000370ef0
[445771.686273] Call Trace:
[445771.686646] <TASK>
[445771.686969] btrfs_submit_bbio+0x83f/0x860 [btrfs]
[445771.687750] ? write_one_eb+0x28f/0x340 [btrfs]
[445771.688428] btree_writepages+0x2e3/0x550 [btrfs]
[445771.689180] ? kmem_cache_alloc_noprof+0x12a/0x490
[445771.689963] ? alloc_extent_state+0x19/0x120 [btrfs]
[445771.690801] ? kmem_cache_free+0x135/0x380
[445771.691328] ? preempt_count_add+0x69/0xa0
[445771.691831] ? set_extent_bit+0x252/0x8e0 [btrfs]
[445771.692468] ? xas_load+0x9/0xc0
[445771.692873] ? xas_find+0x14d/0x1a0
[445771.693304] do_writepages+0xc6/0x160
[445771.693756] filemap_writeback+0xb8/0xe0
[445771.694274] btrfs_write_marked_extents+0x61/0x170 [btrfs]
[445771.694999] btrfs_write_and_wait_transaction+0x4e/0xc0 [btrfs]
[445771.695818] btrfs_commit_transaction+0x5c8/0xd10 [btrfs]
[445771.696530] ? kmem_cache_free+0x135/0x380
[445771.697120] ? release_extent_buffer+0x34/0x160 [btrfs]
[445771.697786] btrfs_recover_log_trees+0x7be/0x7e0 [btrfs]
[445771.698525] ? __pfx_replay_one_buffer+0x10/0x10 [btrfs]
[445771.699206] open_ctree+0x11e5/0x1810 [btrfs]
[445771.699776] btrfs_get_tree.cold+0xb/0x162 [btrfs]
[445771.700463] ? fscontext_read+0x165/0x180
[445771.701146] ? rw_verify_area+0x50/0x180
[445771.701866] vfs_get_tree+0x25/0xd0
[445771.702491] vfs_cmd_create+0x59/0xe0
[445771.703125] __do_sys_fsconfig+0x303/0x610
[445771.703603] do_syscall_64+0xe9/0xf20
[445771.703974] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[445771.704700] RIP: 0033:0x7f0447cbd4aa
[445771.705108] Code: 73 01 c3 (...)
[445771.707263] RSP: 002b:
00007ffc4e528318 EFLAGS:
00000246 ORIG_RAX:
00000000000001af
[445771.708107] RAX:
ffffffffffffffda RBX:
00005561585d8c20 RCX:
00007f0447cbd4aa
[445771.708931] RDX:
0000000000000000 RSI:
0000000000000006 RDI:
0000000000000003
[445771.709744] RBP:
00005561585d9120 R08:
0000000000000000 R09:
0000000000000000
[445771.710674] R10:
0000000000000000 R11:
0000000000000246 R12:
0000000000000000
[445771.711477] R13:
00007f0447e4f580 R14:
00007f0447e5126c R15:
00007f0447e36a23
[445771.712277] </TASK>
[445771.712541] ---[ end trace
0000000000000000 ]---
[445771.713382] BTRFS error (device dm-0): error while writing out transaction: -5
[445771.714679] BTRFS warning (device dm-0): Skipping commit of aborted transaction.
[445771.715562] BTRFS error (device dm-0 state A): Transaction aborted (error -5)
[445771.716459] BTRFS: error (device dm-0 state A) in cleanup_transaction:2068: errno=-5 IO failure
[445771.717936] BTRFS error (device dm-0 state EA): failed to recover log trees with error: -5
[445771.719681] BTRFS error (device dm-0 state EA): open_ctree failed: -5
The problem is that such a fsync should have result in a fallback to a
transaction commit, but that did not happen because through the
btrfs_rmdir() we never update the directory's last_unlink_trans field.
Any inode that had a link removed must have its last_unlink_trans updated
to the ID of transaction used for the operation, otherwise fsync and log
replay will not work correctly.
btrfs_rmdir() calls btrfs_unlink_inode() and through that call chain we
never call btrfs_record_unlink_dir() in order to update last_unlink_trans.
However btrfs_unlink(), which is used for unlinking regular files, calls
btrfs_record_unlink_dir() and then calls btrfs_unlink_inode(). So fix
this by moving the call to btrfs_record_unlink_dir() from btrfs_unlink()
to btrfs_unlink_inode().
A test case for fstests will follow soon.
Reported-by: Slava0135 <slava.kovalevskiy.2014@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAAJYhww5ov62Hm+n+tmhcL-e_4cBobg+OWogKjOJxVUXivC=MQ@mail.gmail.com/
CC: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>