[PATCH 08/46] mm/filemap: finish fault cleanup before dropping the fault lock

[sashiko-bot at kernel.org]

> On a retried fault, a fatal signal interrupting the folio lock wait
> makes lock_folio_maybe_drop_mmap() drop the fault lock without pinning
> the file. However, filemap_fault() may still need to release
> mapping->invalidate_lock. A concurrent munmap() can release the last
> file reference and free the mapping before that unlock.
> 
> Defer dropping the fault lock to filemap_fault()'s retry cleanup, after
> releasing invalidate_lock. If the fault lock was already dropped for
> I/O, release the existing file reference instead. Keep the fault lock
> held for FAULT_FLAG_RETRY_NOWAIT as before.
> 
> Fixes: 730633f0b7f9 ("mm: Protect operations adding pages to page cache with invalidate_lock")
> Cc: stable at vger.kernel.org
> Reported-by: Chris Mason <mason at kernel.org>
> Signed-off-by: David Hildenbrand (Arm) <david at kernel.org>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org?part=8