Re: [PATCH v3 07/33] jfs: don't set SB_RDONLY after filesystem errors

[sashiko-bot@kernel.org]

> With errors=remount-ro, the jfs default, jfs_handle_error() sets
> SB_RDONLY from whatever context hit the error and without holding
> s_umount. If that happens while the filesystem is frozen thaw_super()
> skips jfs_unfreeze() and leaves the s_writers rwsems locked. Writers
> hang and umount shuts the log down a second time and crashes.
> 
> So call sb_set_emergency_ro() instead and let the VFS refuse
> modifications. jfs_unfreeze() used sb_rdonly() to tell whether
> jfs_freeze() shut the log down. Track that in JFS_FLAGS_LOG_SHUTDOWN
> instead so thaw undoes exactly what freeze did.
> 
> jfs refuses inode and block allocation and the xattr and ACL setters
> itself, before txBegin() because failing txCommit() with tlocks held
> trips an assert. Allocations writeback hasn't committed yet when the
> error hits leave anonymous tlocks behind. So jfs_dirty_inode() still
> [ ... ]
> before the error fail with EROFS.
> 
> Reported-by: Karl Mehltretter <kmehltretter@gmail.com>
> Link: https://lore.kernel.org/r/20260903060855.4610-1-kmehltretter@gmail.com
> 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/20261113-work-fs-sb_rdonly-v3-0-0be92bb73709@kernel.org?part=7