Btrfs: fix warning when replaying log after fsync of a tmpfile
commit
f2d72f42d5fa3bf33761d9e47201745f624fcff5 upstream.
When replaying a log which contains a tmpfile (which necessarily has a
link count of 0) we end up calling inc_nlink(), at
fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like
the following:
[195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40
[195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1
[195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[195191.943726] RIP: 0010:inc_nlink+0x33/0x40
[195191.943728] RSP: 0018:
ffffb96e425e3870 EFLAGS:
00010246
[195191.943730] RAX:
0000000000000000 RBX:
ffff8c0d1e6af4f0 RCX:
0000000000000006
[195191.943731] RDX:
0000000000000000 RSI:
0000000000000000 RDI:
ffff8c0d1e6af4f0
[195191.943731] RBP:
0000000000000097 R08:
0000000000000001 R09:
0000000000000000
[195191.943732] R10:
0000000000000000 R11:
0000000000000000 R12:
ffffb96e425e3a60
[195191.943733] R13:
ffff8c0d10cff0c8 R14:
ffff8c0d0d515348 R15:
ffff8c0d78a1b3f8
[195191.943735] FS:
00007f570ee24480(0000) GS:
ffff8c0dfb200000(0000) knlGS:
0000000000000000
[195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[195191.943737] CR2:
00005593286277c8 CR3:
00000000bb8f2006 CR4:
00000000003606f0
[195191.943739] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[195191.943740] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[195191.943741] Call Trace:
[195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs]
[195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs]
[195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943825] walk_log_tree+0xae/0x1d0 [btrfs]
[195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs]
[195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs]
[195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs]
[195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs]
[195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943899] ? pcpu_alloc+0x55b/0x7c0
[195191.943906] ? mount_fs+0x3b/0x140
[195191.943908] mount_fs+0x3b/0x140
[195191.943912] ? __init_waitqueue_head+0x36/0x50
[195191.943916] vfs_kern_mount+0x62/0x160
[195191.943927] btrfs_mount+0x134/0x890 [btrfs]
[195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70
[195191.943938] ? pcpu_alloc+0x55b/0x7c0
[195191.943943] ? mount_fs+0x3b/0x140
[195191.943952] ? btrfs_remount+0x570/0x570 [btrfs]
[195191.943954] mount_fs+0x3b/0x140
[195191.943956] ? __init_waitqueue_head+0x36/0x50
[195191.943960] vfs_kern_mount+0x62/0x160
[195191.943963] do_mount+0x1f9/0xd40
[195191.943967] ? memdup_user+0x4b/0x70
[195191.943971] ksys_mount+0x7e/0xd0
[195191.943974] __x64_sys_mount+0x21/0x30
[195191.943977] do_syscall_64+0x60/0x1b0
[195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[195191.943983] RIP: 0033:0x7f570e4e524a
[195191.943986] RSP: 002b:
00007ffd83589478 EFLAGS:
00000206 ORIG_RAX:
00000000000000a5
[195191.943989] RAX:
ffffffffffffffda RBX:
0000563f335b2060 RCX:
00007f570e4e524a
[195191.943990] RDX:
0000563f335b2240 RSI:
0000563f335b2280 RDI:
0000563f335b2260
[195191.943992] RBP:
0000000000000000 R08:
0000000000000000 R09:
0000000000000020
[195191.943993] R10:
00000000c0ed0000 R11:
0000000000000206 R12:
0000563f335b2260
[195191.943994] R13:
0000563f335b2240 R14:
0000000000000000 R15:
00000000ffffffff
[195191.944002] irq event stamp: 8688
[195191.944010] hardirqs last enabled at (8687): [<
ffffffff9cb004c3>] console_unlock+0x503/0x640
[195191.944012] hardirqs last disabled at (8688): [<
ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
[195191.944018] softirqs last enabled at (8638): [<
ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150
[195191.944020] softirqs last disabled at (8634): [<
ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60
[195191.944022] ---[ end trace
5d6e873a9a0b811a ]---
This happens because the inode does not have the flag I_LINKABLE set,
which is a runtime only flag, not meant to be persisted, set when the
inode is created through open(2) if the flag O_EXCL is not passed to it.
Except for the warning, there are no other consequences (like corruptions
or metadata inconsistencies).
Since it's pointless to replay a tmpfile as it would be deleted in a
later phase of the log replay procedure (it has a link count of 0), fix
this by not logging tmpfiles and if a tmpfile is found in a log (created
by a kernel without this change), skip the replay of the inode.
A test case for fstests follows soon.
Fixes:
471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay")
CC: stable@vger.kernel.org # 4.18+
Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>