On 3/16/17 4:42 PM, Dave Chinner wrote: > On Thu, Mar 16, 2017 at 12:15:00PM -0700, Darrick J. Wong wrote: >> On Wed, Mar 15, 2017 at 07:36:29AM -0400, Brian Foster wrote: >>> On Tue, Mar 14, 2017 at 06:23:57PM -0500, Eric Sandeen wrote: >>>> When we do log recovery on a readonly mount, unlinked inode >>>> processing does not happen due to the readonly checks in >>>> xfs_inactive(), which are trying to prevent any I/O on a >>>> readonly mount. >>>> >>>> This is misguided - we do I/O on readonly mounts all the time, >>>> for consistency; for example, log recovery. So do the same >>>> RDONLY flag twiddling around xfs_log_mount_finish() as we >>>> do around xfs_log_mount(), for the same reason. >>>> >>>> This all cries out for a big rework but for now this is a >>>> simple fix to an obvious problem. >>>> >>>> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> >>>> --- >>>> >> >> Both patches look ok, so I'll put them on the test queue for -rc4. >> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > FWIW, I don't think this is a -rc candidate. Making log recovery > process unlinked inode transactions on read-only mounts is a pretty > major change in behaviour. Who knows exactly what dragons are > lurking at lower layers that have never been run in this context > until now. > > Also, it's not urgent - we've lived with this behaviour for years - > so waiting a month for the next merge window is not going to hurt > anyone and it gives us a chance to test it - XFS developers are the > people who should be burnt by the lurking dragons, not users who > updated to a late -rcX kernel.... To shield Darrick a bit ;) I was agitating/asking for sooner, but admittedly that was a little bit selfish on my part. Still, we have had field reports of people with /gigabytes/ missing from the root filesystem, and it was not fixable without an xfs_repair. Which on a root filesystem is ... special. So, my fault for getting it sent late, for sure - but I do think it's an important fix. I know we can't really address the "unknown unknown" dragons easily, but actually completing recovery on RO mounts seems straightforward to me... we allow half of recovery to go, and disallow the other half. Seems plainly broken. -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
