Re: [PATCH v2 08/34] exfat: keep the current mount options on remount

[sashiko-bot@kernel.org]

> exfat_init_fs_context() only inherits uid, gid, fmask and dmask for a
> reconfigure. But exfat_reconfigure() refuses to change iocharset,
> keep_last_dots, sys_tz, time_offset and allow_utime. So every remount
> that doesn't repeat a non-default value for one of them fails with
> EINVAL, including emergency remount (sysrq u) which passes no options at
> all. And an option-less remount silently resets errors=, zero_size_dir
> and discard.
> 
> So start a reconfigure from the current options like gfs2 does. The
> iocharset string stays NULL in the new context because
> ->init_fs_context() runs without s_umount for mount(2) and a concurrent
> remount could free it. It's only compared if the remount names one. A
> shutdown turns discard off for good so exfat_reconfigure() keeps it off.
> 
> The next patch stops exfat from setting SB_RDONLY after errors. An
> errored exfat then stays read-write and emergency remount would run into
> this as well.
> 
> Fixes: e6fd5d3a4317 ("exfat: support modifying mount options via remount")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261029-work-fs-sb_rdonly-v2-0-2f44f64f0b66@kernel.org?part=8