xfs: acquire ->ail_lock from xfs_trans_ail_delete()

Several callers acquire the lock just prior to the call. Callers
that require ->ail_lock for other purposes already check IN_AIL
state and thus don't require the additional shutdown check in the
helper. Push the lock down into xfs_trans_ail_delete(), open code
the instances that still acquire it, and remove the unnecessary ailp
parameter.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_buf_item.c

@@ -410,7 +410,6 @@ xfs_buf_item_unpin(
 {
 	struct xfs_buf_log_item	*bip = BUF_ITEM(lip);
 	xfs_buf_t		*bp = bip->bli_buf;
-	struct xfs_ail		*ailp = lip->li_ailp;
 	int			stale = bip->bli_flags & XFS_BLI_STALE;
 	int			freed;
 
@@ -452,10 +451,10 @@ xfs_buf_item_unpin(
 		}
 
 		/*
-		 * If we get called here because of an IO error, we may
-		 * or may not have the item on the AIL. xfs_trans_ail_delete()
-		 * will take care of that situation.
-		 * xfs_trans_ail_delete() drops the AIL lock.
+		 * If we get called here because of an IO error, we may or may
+		 * not have the item on the AIL. xfs_trans_ail_delete() will
+		 * take care of that situation. xfs_trans_ail_delete() drops
+		 * the AIL lock.
 		 */
 		if (bip->bli_flags & XFS_BLI_STALE_INODE) {
 			xfs_buf_do_callbacks(bp);
@@ -463,8 +462,7 @@ xfs_buf_item_unpin(
 			list_del_init(&bp->b_li_list);
 			bp->b_iodone = NULL;
 		} else {
-			spin_lock(&ailp->ail_lock);
-			xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR);
+			xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
 			xfs_buf_item_relse(bp);
 			ASSERT(bp->b_log_item == NULL);
 		}
@@ -1205,22 +1203,19 @@ xfs_buf_iodone(
 	struct xfs_buf		*bp,
 	struct xfs_log_item	*lip)
 {
-	struct xfs_ail		*ailp = lip->li_ailp;
-
 	ASSERT(BUF_ITEM(lip)->bli_buf == bp);
 
 	xfs_buf_rele(bp);
 
 	/*
-	 * If we are forcibly shutting down, this may well be
-	 * off the AIL already. That's because we simulate the
-	 * log-committed callbacks to unpin these buffers. Or we may never
-	 * have put this item on AIL because of the transaction was
-	 * aborted forcibly. xfs_trans_ail_delete() takes care of these.
+	 * If we are forcibly shutting down, this may well be off the AIL
+	 * already. That's because we simulate the log-committed callbacks to
+	 * unpin these buffers. Or we may never have put this item on AIL
+	 * because of the transaction was aborted forcibly.
+	 * xfs_trans_ail_delete() takes care of these.
 	 *
 	 * Either way, AIL is useless if we're forcing a shutdown.
 	 */
-	spin_lock(&ailp->ail_lock);
-	xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
+	xfs_trans_ail_delete(lip, SHUTDOWN_CORRUPT_INCORE);
 	xfs_buf_item_free(BUF_ITEM(lip));
 }