Re: XFS: false "torn write" errors (preventing mount)
From: Brian Foster <hidden>
Date: 2016-02-29 18:08:09
On Mon, Feb 29, 2016 at 10:57:52AM -0500, Brian Foster wrote:
On Mon, Feb 29, 2016 at 08:29:20AM -0700, Jan Beulich wrote:quoted
Brian, on a system where I routinely run both a 32-bit and a 64-bit x86 kernel (underneath the same 32-bit distro) I'm observing the newly added message being issued, along with the mounts subsequently failing when running the 32-bit kernel. Without doing anything to the FS, running an older 32-bit kernel or a 4.5-rc6 64-bit one have everything work fine (and silently), so I can only assume the detection logic doesn't work right in a 32-bit kernel. I've looked over commits 6528250b71 and 7088c4136f without being able to spot any obvious word size dependency, but then again I know nothing about the inner workings of the XFS code. I'm now hoping that you have an idea what's going on here.There was one follow on fix related to byte order: 8e0bd4925bf6 ("xfs: fix endianness error when checking log block crc on big endian platforms"), but I don't think that would have any effect on an x86 kernel. Is the 32-bit kernel problematic on its own, or must the 64-bit kernel be involved somehow before the 32-bit kernel reproduces a problem? For example, can you mkfs, mount and remount (perhaps multiple times) on the 32-bit kernel without a problem? If so, what happens if you transition to the 64-bit kernel, remount a few times, and then go back to 32-bit? In general, anything that narrows down the reproducer is helpful. I don't appear to have a 32-bit env. handy so I'll kick off an install in the meantime and take a closer look from there...
Just a heads up that I've been able to reproduce. What I think might be going on is that the log is clean, but the log recovery pass looks back behind the latest unmount record, runs into some records/data written by the alternate architecture from that which is running, and then fails due to crc mismatch. The problem doesn't seem to manifest right away, however, so I could still be missing something here. Anyways, I'll dig into it and try to come up with a fix. Thanks for the report! Brian
Brianquoted
Thanks, Jan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs_______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs
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