Re: [PATCH v2 00/12] lazytime fix and cleanups

On Mon, Jan 11, 2021 at 04:15:17PM +0100, Jan Kara wrote:

Hi!

On Fri 08-01-21 23:58:51, Eric Biggers wrote:

quoted

Hello,

Patch 1 fixes a bug in how __writeback_single_inode() handles lazytime
expirations.  I originally reported this last year
(https://lore.kernel.org/r/20200306004555.GB225345@gmail.com (local)) because it
causes the FS_IOC_REMOVE_ENCRYPTION_KEY ioctl to not work properly, as
the bug causes inodes to remain dirty after a sync.

It also turns out that lazytime on XFS is partially broken because it
doesn't actually write timestamps to disk after a sync() or after
dirtytime_expire_interval.  This is fixed by the same fix.

This supersedes previously proposed fixes, including
https://lore.kernel.org/r/20200307020043.60118-1-tytso@mit.edu (local) and
https://lore.kernel.org/r/20200325122825.1086872-3-hch@lst.de (local) from last
year (which had some issues and didn't fix the XFS bug), and v1 of this
patchset which took a different approach
(https://lore.kernel.org/r/20210105005452.92521-1-ebiggers@kernel.org (local)).

Patches 2-12 then clean up various things related to lazytime and
writeback, such as clarifying the semantics of ->dirty_inode() and the
inode dirty flags, and improving comments.  Most of these patches could
be applied independently if needed.

This patchset applies to v5.11-rc2.

The series look good to me. How do you plan to merge it (after resolving
Christoph's remarks)? I guess either Ted can take it through the ext4 tree
or I can take it through my tree...

I think taking it through your tree would be best, unless Al or Ted wants to
take it.

I'll probably separate out
"xfs: remove a stale comment from xfs_file_aio_write_checks()",
since it isn't really related anymore and could go in through the XFS tree.

- Eric