From: Jan Kara <jack@suse.cz>
To: Richard Weinberger <richard@nod.at>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
"Theodore Ts'o" <tytso@mit.edu>, Jan Kara <jack@suse.cz>,
octavian.purdila@intel.com, Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: WARNING: CPU: 0 PID: 1 at fs/block_dev.c:58 __blkdev_put+0x16f/0x1b0()
Date: Mon, 9 Nov 2015 10:22:34 +0100 [thread overview]
Message-ID: <20151109092234.GA11149@quack.suse.cz> (raw)
In-Reply-To: <563DE982.1070707@nod.at>
Hi!
On Sat 07-11-15 13:07:30, Richard Weinberger wrote:
> While playing with the Linux kernel library I run into this warning.
> Root cause of the warning is that the backing file on the host
> side is locked an therefore all IO on it results into -EIO.
>
> The question is whether ext4/jbd2 should abort earlier or not.
> The WARN_ON_ONCE in bdev_write_inode() triggers as jbd2's do_one_pass()
> sets up a dirty buffer_head and fails later.
> Then ext4 gives up, calls blkdev_put() and we reach bdev_write_inode()
> with a dirty ->bd_inode.
>
> What do you think?
So I think the right question is what we should do when we cannot writeback
dirty data. Currently we WARN_ON in some places (bdev_write_inode() is one
of them) and print errors in others. Although loosing data is nasty, people
seem to remove devices or do similar stuff too often for WARN_ON to be really
an adequate answer... So I think we should just print error message and go
on without spewing stack traces. Thoughts?
Honza
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 0
> [ 0.128000] Buffer I/O error on dev vda, logical block 0, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 8
> [ 0.128000] Buffer I/O error on dev vda, logical block 1, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 528
> [ 0.128000] Buffer I/O error on dev vda, logical block 66, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 1824
> [ 0.128000] Buffer I/O error on dev vda, logical block 228, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 1864
> [ 0.128000] Buffer I/O error on dev vda, logical block 233, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 41840
> [ 0.128000] Buffer I/O error on dev vda, logical block 5230, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 262672
> [ 0.128000] Buffer I/O error on dev vda, logical block 32834, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 262680
> [ 0.128000] Buffer I/O error on dev vda, logical block 32835, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 262752
> [ 0.128000] Buffer I/O error on dev vda, logical block 32844, lost async page write
> [ 0.128000] blk_update_request: I/O error, dev vda, sector 262792
> [ 0.128000] Buffer I/O error on dev vda, logical block 32849, lost async page write
> [ 0.132000] JBD2: recovery failed
> [ 0.132000] EXT4-fs (vda): error loading journal
> [ 0.132000] ------------[ cut here ]------------
> [ 0.132000] WARNING: CPU: 0 PID: 1 at fs/block_dev.c:58 __blkdev_put+0x16f/0x1b0()
> [ 0.132000] Call Trace:
> [ 0.132000] 00007fd99262db68: [<0040673d>] warn_slowpath_common+0x7d/0xb0
> [ 0.132000] 00007fd99262dba8: [<004068d5>] warn_slowpath_null+0x15/0x20
> [ 0.132000] 00007fd99262dbb8: [<0048efbf>] __blkdev_put+0x16f/0x1b0
> [ 0.132000] 00007fd99262dbf8: [<0048fcd2>] blkdev_put+0x92/0x110
> [ 0.132000] 00007fd99262dc28: [<00462faf>] kill_block_super+0x3f/0x70
> [ 0.132000] 00007fd99262dc48: [<00461bf2>] deactivate_locked_super+0x52/0xb0
> [ 0.132000] 00007fd99262dc78: [<00462f51>] mount_bdev+0x1b1/0x1d0
> [ 0.132000] 00007fd99262dc80: [<004c5c40>] ext4_fill_super+0x0/0x32f0
> [ 0.132000] 00007fd99262dce8: [<004c16f0>] ext4_mount+0x10/0x20
> [ 0.132000] 00007fd99262dcf8: [<00463164>] mount_fs+0x14/0xc0
> [ 0.132000] 00007fd99262dd28: [<0047a38e>] vfs_kern_mount+0x5e/0x120
> [ 0.132000] 00007fd99262dd78: [<0047baa8>] do_mount+0x208/0xd90
> [ 0.132000] 00007fd99262dd88: [<0045d7db>] __kmalloc_track_caller+0x18b/0x1c0
> [ 0.132000] 00007fd99262dd98: [<00450618>] strndup_user+0x48/0x60
> [ 0.132000] 00007fd99262de08: [<00450618>] strndup_user+0x48/0x60
> [ 0.132000] 00007fd99262de48: [<0047c99a>] SyS_mount+0x6a/0xb0
> [ 0.132000] 00007fd99262de98: [<00403b89>] run_syscalls+0xd9/0x1c0
> [ 0.132000] 00007fd99262deb0: [<00425970>] autoremove_wake_function+0x0/0x40
> [ 0.132000] 00007fd99262dec8: [<005535f0>] kernel_init+0x0/0xf0
> [ 0.132000] 00007fd99262dee8: [<005535f0>] kernel_init+0x0/0xf0
> [ 0.132000] 00007fd99262df08: [<00402f2d>] run_init_process+0x1d/0x40
> [ 0.132000] 00007fd99262df18: [<00553626>] kernel_init+0x36/0xf0
> [ 0.132000] 00007fd99262df28: [<00403158>] thread_bootstrap+0x48/0x50
> [ 0.132000]
> [ 0.132000] ---[ end trace 0b886a9a044a4995 ]---
>
> Thanks,
> //richard
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2015-11-09 9:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-07 12:07 WARNING: CPU: 0 PID: 1 at fs/block_dev.c:58 __blkdev_put+0x16f/0x1b0() Richard Weinberger
2015-11-09 9:22 ` Jan Kara [this message]
2015-11-09 16:13 ` Jeff Moyer
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