RHEL6/RHEL7: kernel crash in btrfs_release_extent_buffer_page - kernel BUG at fs/btrfs/extent_io.c:4041!
Issue
- Two hosts that make use of btrfs and its snapshot feature crash often the message "kernel BUG at fs/btrfs/extent_io.c:4041". Probably the crashes happen in time correlation with new snapshots.
- kernel crash in
btrfs_release_extent_buffer_page
with the following oops from btrfs-endio-wri
kernel BUG at fs/btrfs/extent_io.c:4041!
invalid opcode: 0000 [#1] SMP
...
Pid: 39533, comm: btrfs-endio-wri Tainted: G -- ------------ T 2.6.32-573.1.1.el6.x86_64 #1 Dell Inc. PowerEdge R720/0020HJ
RIP: 0010:[<ffffffffa03e9550>] [<ffffffffa03e9550>] btrfs_release_extent_buffer_page.clone.0+0x90/0x120 [btrfs]
...
Call Trace:
[<ffffffffa03e9a9a>] release_extent_buffer+0x4a/0xe0 [btrfs]
[<ffffffffa03e9c9c>] free_extent_buffer+0x3c/0xa0 [btrfs]
[<ffffffffa03a0c81>] btrfs_release_path+0x31/0x90 [btrfs]
[<ffffffffa03bc4fa>] btrfs_csum_file_blocks+0x49a/0x6d0 [btrfs]
[<ffffffffa03d4314>] ? insert_reserved_file_extent.clone.0+0x94/0x270 [btrfs]
[<ffffffffa03c8eb9>] add_pending_csums+0x49/0x70 [btrfs]
[<ffffffffa03d4755>] btrfs_finish_ordered_io+0x265/0x3f0 [btrfs]
[<ffffffff81089c10>] ? process_timeout+0x0/0x10
[<ffffffffa03d48f5>] finish_ordered_fn+0x15/0x20 [btrfs]
[<ffffffffa03f8a02>] worker_loop+0x142/0x550 [btrfs]
[<ffffffffa03f88c0>] ? worker_loop+0x0/0x550 [btrfs]
[<ffffffff810a101e>] kthread+0x9e/0xc0
[<ffffffff8100c28a>] child_rip+0xa/0x20
[<ffffffff810a0f80>] ? kthread+0x0/0xc0
[<ffffffff8100c280>] ? child_rip+0x0/0x20
Code: 00 00 48 83 eb 01 4c 8b 24 d8 4d 85 e4 75 24 0f 1f 40 00 48 85 db 75 e3 5b 41 5c 41 5d 41 5e c9 c3 66 2e 0f 1f 84 00 00 00 00 00 <0f> 0b eb fe 0f 1f 40 00 45 84 f6 75 13 4c 89 e7 e8 8b 48 d5 e0
RIP [<ffffffffa03e9550>] btrfs_release_extent_buffer_page.clone.0+0x90/0x120 [btrfs]
RSP <ffff881f9cb87c10>
Environment
- Red Hat Enterprise Linux 6
- seen on kernel-2.6.32-573.1.1.el6, other kernels likely affected
- Red Hat Enterprise Linux 7
- seen on kernel-3.10.0-327.22.2.el7, other kernels likely affected
- brtfs
- NOTE: btrfs is a Technology Preview kernel module
crash> mod -t
NAME TAINTS
btrfs T << Tech preview module
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