[Ocfs2-devel] ocfs2: kernel BUG at fs/ocfs2/buffer_head_io.c

[Joseph Qi]

I have triggered a BUG at buffer_head_io.c. Belowing is the code where
the BUG is triggered:
if (buffer_needs_validate(bh)) {
	/* We never set NeedsValidate if the
	 * buffer was held by the journal, so
	 * that better not have changed */
	BUG_ON(buffer_jbd(bh));
	clear_buffer_needs_validate(bh);
	status = validate(sb, bh);
	if (status) {
		put_bh(bh);
		bhs[i] = NULL;
		continue;
	}
}

As the comment says, BH_NeedsValidate and buffer_jbd are mutually
exclusive. Has anyone else also encountered this issue? My case is
iSCSI link down and then restore with system 80% stress.

Here is the stack:
[ 2406.046006] kernel BUG at fs/ocfs2/buffer_head_io.c:343!
[ 2406.046010] invalid opcode: 0000 [#1] SMP
...
[ 2406.046226] Pid: 10743, comm: fio Tainted: G          N  3.0.13-0.27-xen #2 Tecal RH2285          
[ 2406.046233] RIP: e030:[<ffffffffa05a7e84>]  [<ffffffffa05a7e84>] ocfs2_read_blocks+0x734/0x8d0 [ocfs2]
[ 2406.046254] RSP: e02b:ffff8800e41a9c18  EFLAGS: 00010206
[ 2406.046259] RAX: 0000000000000000 RBX: ffff8800f9a27470 RCX: 0000000000000008
[ 2406.046265] RDX: 0000000002310029 RSI: ffff8800f9a27470 RDI: ffff8800f9bb7690
[ 2406.046270] RBP: 0000000000000000 R08: ffff8800e3684b48 R09: 0000000000000002
[ 2406.046276] R10: ffff8800f9bb76d8 R11: ffffffffa05cbc20 R12: ffff8800e41a9cf0
[ 2406.046282] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 2406.046292] FS:  00007f871f4a8700(0000) GS:ffff88000401a000(0000) knlGS:0000000000000000
[ 2406.046298] CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 2406.046303] CR2: 00007f871e585820 CR3: 00000000e7870000 CR4: 0000000000002620
[ 2406.046309] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2406.046315] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 2406.046321] Process fio (pid: 10743, threadinfo ffff8800e41a8000, task ffff8800e41ae5c0)
[ 2406.046327] Stack:
[ 2406.046330]  ffff8800e41ae5c0 ffff8800f9bb726c 000000003432205b 0000000500000008
[ 2406.046338] <0> ffff8800e41aea68 ffff8800e41ae5c0 ffff8800e41aea68 ffff8800e41ae5c0
[ 2406.046349] <0> 00000000f9bb726c ffff8800e41aea68 ffff8800e41ae5c0 ffffffffa05cc2f0
[ 2406.046360] Call Trace:
[ 2406.046393]  [<ffffffffa05cbdd7>] ocfs2_read_inode_block_full+0x37/0x60 [ocfs2]
[ 2406.046423]  [<ffffffffa05bee5d>] ocfs2_inode_lock_full_nested+0x5bd/0xdd0 [ocfs2]
[ 2406.046451]  [<ffffffffa05c9f9d>] __ocfs2_change_file_space+0x1bd/0x1800 [ocfs2]
[ 2406.046480]  [<ffffffffa05cb669>] ocfs2_fallocate+0x89/0x90 [ocfs2]
[ 2406.046503]  [<ffffffff800d7264>] do_fallocate+0x104/0x110
[ 2406.046512]  [<ffffffff800d72b6>] sys_fallocate+0x46/0x70
[ 2406.046521]  [<ffffffff80007378>] system_call_fastpath+0x16/0x1b
[ 2406.046530]  [<00007f871e585845>] 0x7f871e585845
[ 2406.046534] Code: ea ff ff ff 41 b9 c6 00 00 00 49 c7 c0 40 4b 62 a0 48 c7 c7 28 f8 62 a0 31 c0 e8 1d f3 dc df 48 8b 05 81 58 f8 ff e9 87 fe ff ff <0f> 0b eb fe 48 8b bc 24 80 00 00 00 41 bd 01 00 00 00 e8 95 0c 
[ 2406.046611] RIP  [<ffffffffa05a7e84>] ocfs2_read_blocks+0x734/0x8d0 [ocfs2]
[ 2406.046625]  RSP <ffff8800e41a9c18>