Commit 22b8077d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'fscache-fixes-20230130' of... 

Merge tag 'fscache-fixes-20230130' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fscache fixes from David Howells:
 "Fix two problems in fscache volume handling:

   - wake_up_bit() is incorrectly paired with wait_var_event(). The
     latter selects the waitqueue to use differently.

   - Missing barriers ordering between state bit and task state"

* tag 'fscache-fixes-20230130' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()
  fscache: Use wait_on_bit() to wait for the freeing of relinquished volume
parents 6d796c50 3288666c

fs/fscache/volume.c

+7 −7
Original line number Diff line number Diff line
@@ -141,13 +141,14 @@ static bool fscache_is_acquire_pending(struct fscache_volume *volume) 
static void fscache_wait_on_volume_collision(struct fscache_volume *candidate,

					     unsigned int collidee_debug_id)

{

	wait_var_event_timeout(&candidate->flags,

			       !fscache_is_acquire_pending(candidate), 20 * HZ);

	wait_on_bit_timeout(&candidate->flags, FSCACHE_VOLUME_ACQUIRE_PENDING,

			    TASK_UNINTERRUPTIBLE, 20 * HZ);

	if (fscache_is_acquire_pending(candidate)) {

		pr_notice("Potential volume collision new=%08x old=%08x",

			  candidate->debug_id, collidee_debug_id);

		fscache_stat(&fscache_n_volumes_collision);

		wait_var_event(&candidate->flags, !fscache_is_acquire_pending(candidate));

		wait_on_bit(&candidate->flags, FSCACHE_VOLUME_ACQUIRE_PENDING,

			    TASK_UNINTERRUPTIBLE);

	}

}
@@ -279,8 +280,7 @@ static void fscache_create_volume_work(struct work_struct *work) 
	fscache_end_cache_access(volume->cache,

				 fscache_access_acquire_volume_end);



	clear_bit_unlock(FSCACHE_VOLUME_CREATING, &volume->flags);

	wake_up_bit(&volume->flags, FSCACHE_VOLUME_CREATING);

	clear_and_wake_up_bit(FSCACHE_VOLUME_CREATING, &volume->flags);

	fscache_put_volume(volume, fscache_volume_put_create_work);

}
@@ -347,8 +347,8 @@ static void fscache_wake_pending_volume(struct fscache_volume *volume, 
	hlist_bl_for_each_entry(cursor, p, h, hash_link) {

		if (fscache_volume_same(cursor, volume)) {

			fscache_see_volume(cursor, fscache_volume_see_hash_wake);

			clear_bit(FSCACHE_VOLUME_ACQUIRE_PENDING, &cursor->flags);

			wake_up_bit(&cursor->flags, FSCACHE_VOLUME_ACQUIRE_PENDING);

			clear_and_wake_up_bit(FSCACHE_VOLUME_ACQUIRE_PENDING,

					      &cursor->flags);

			return;

		}

	}