btrfs: fix warning when freeing leaf after subvolume creation failure
When creating a subvolume, at ioctl.c:create_subvol(), if we fail to
insert the root item for the new subvolume into the root tree, we can
trigger the following warning:
[78961.741046] WARNING: CPU: 0 PID: 4079814 at fs/btrfs/extent-tree.c:3357 btrfs_free_tree_block+0x2af/0x310 [btrfs]
[78961.743344] Modules linked in:
[78961.749440] dm_snapshot dm_thin_pool (...)
[78961.773648] CPU: 0 PID: 4079814 Comm: fsstress Not tainted 5.16.0-rc4-btrfs-next-108 #1
[78961.775198] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[78961.777266] RIP: 0010:btrfs_free_tree_block+0x2af/0x310 [btrfs]
[78961.778398] Code: 17 00 48 85 (...)
[78961.781067] RSP: 0018:
ffffaa4001657b28 EFLAGS:
00010202
[78961.781877] RAX:
0000000000000213 RBX:
ffff897f8a796910 RCX:
0000000000000000
[78961.782780] RDX:
0000000000000000 RSI:
0000000011004000 RDI:
00000000ffffffff
[78961.783764] RBP:
ffff8981f490e800 R08:
0000000000000001 R09:
0000000000000000
[78961.784740] R10:
0000000000000000 R11:
0000000000000001 R12:
ffff897fc963fcc8
[78961.785665] R13:
0000000000000001 R14:
ffff898063548000 R15:
ffff898063548000
[78961.786620] FS:
00007f31283c6b80(0000) GS:
ffff8982ace00000(0000) knlGS:
0000000000000000
[78961.787717] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[78961.788598] CR2:
00007f31285c3000 CR3:
000000023fcc8003 CR4:
0000000000370ef0
[78961.789568] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[78961.790585] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[78961.791684] Call Trace:
[78961.792082] <TASK>
[78961.792359] create_subvol+0x5d1/0x9a0 [btrfs]
[78961.793054] btrfs_mksubvol+0x447/0x4c0 [btrfs]
[78961.794009] ? preempt_count_add+0x49/0xa0
[78961.794705] __btrfs_ioctl_snap_create+0x123/0x190 [btrfs]
[78961.795712] ? _copy_from_user+0x66/0xa0
[78961.796382] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[78961.797392] btrfs_ioctl+0xd1e/0x35c0 [btrfs]
[78961.798172] ? __slab_free+0x10a/0x360
[78961.798820] ? rcu_read_lock_sched_held+0x12/0x60
[78961.799664] ? lock_release+0x223/0x4a0
[78961.800321] ? lock_acquired+0x19f/0x420
[78961.800992] ? rcu_read_lock_sched_held+0x12/0x60
[78961.801796] ? trace_hardirqs_on+0x1b/0xe0
[78961.802495] ? _raw_spin_unlock_irqrestore+0x3e/0x60
[78961.803358] ? kmem_cache_free+0x321/0x3c0
[78961.804071] ? __x64_sys_ioctl+0x83/0xb0
[78961.804711] __x64_sys_ioctl+0x83/0xb0
[78961.805348] do_syscall_64+0x3b/0xc0
[78961.805969] entry_SYSCALL_64_after_hwframe+0x44/0xae
[78961.806830] RIP: 0033:0x7f31284bc957
[78961.807517] Code: 3c 1c 48 f7 d8 (...)
This is because we are calling btrfs_free_tree_block() on an extent
buffer that is dirty. Fix that by cleaning the extent buffer, with
btrfs_clean_tree_block(), before freeing it.
This was triggered by test case generic/475 from fstests.
Fixes:
67addf29004c5b ("btrfs: fix metadata extent leak after failure to create subvolume")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>