xfs: check for not fully initialized inodes in xfs_ireclaim

commit b44b1126 upstream

Add an assert for inodes not added to the inode cache in xfs_ireclaim,
to make sure we're not going to introduce something like the
famous nfsd inode cache bug again.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/xfs/xfs_iget.c

@@ -511,17 +511,21 @@ xfs_ireclaim(
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_perag	*pag;
+	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
 
 	XFS_STATS_INC(xs_ig_reclaims);
 
 	/*
-	 * Remove the inode from the per-AG radix tree.  It doesn't matter
-	 * if it was never added to it because radix_tree_delete can deal
-	 * with that case just fine.
+	 * Remove the inode from the per-AG radix tree.
+	 *
+	 * Because radix_tree_delete won't complain even if the item was never
+	 * added to the tree assert that it's been there before to catch
+	 * problems with the inode life time early on.
 	 */
 	pag = xfs_get_perag(mp, ip->i_ino);
 	write_lock(&pag->pag_ici_lock);
-	radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino));
+	if (!radix_tree_delete(&pag->pag_ici_root, agino))
+		ASSERT(0);
 	write_unlock(&pag->pag_ici_lock);
 	xfs_put_perag(mp, pag);