xfs: don't create a slab cache for filestream items

We only have very few of these around, and allocation isn't that
much of a hot path.  Remove the slab cache to simplify the code,
and to not waste any resources for the usual case of not having
any inodes that use the filestream allocator.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_filestream.c

@@ -39,8 +39,6 @@
 #define TRACE_FREE(mp, ip, pip, ag, cnt)
 #define TRACE_LOOKUP(mp, ip, pip, ag, cnt)
 
-static kmem_zone_t *item_zone;
-
 struct xfs_fstrm_item {
 	struct xfs_mru_cache_elem	mru;
 	struct xfs_inode		*ip;
@@ -141,7 +139,7 @@ xfs_fstrm_free_func(
 	TRACE_FREE(mp, ip, NULL, item->ag,
 		   xfs_filestream_peek_ag(mp, item->ag));
 
-	kmem_zone_free(item_zone, item);
+	kmem_free(item);
 }
 
 /*
@@ -272,7 +270,7 @@ xfs_filestream_pick_ag(
 		return 0;
 
 	err = ENOMEM;
-	item = kmem_zone_zalloc(item_zone, KM_MAYFAIL);
+	item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
 	if (!item)
 		goto out_put_ag;
 
@@ -289,7 +287,7 @@ xfs_filestream_pick_ag(
 	return 0;
 
 out_free_item:
-	kmem_zone_free(item_zone, item);
+	kmem_free(item);
 out_put_ag:
 	xfs_filestream_put_ag(mp, *agp);
 	return err;
@@ -474,20 +472,3 @@ xfs_filestream_unmount(
 {
 	xfs_mru_cache_destroy(mp->m_filestream);
 }
-
-
-/* needs to return a positive errno for the init path */
-int
-xfs_filestream_init(void)
-{
-	item_zone = kmem_zone_init(sizeof(struct xfs_fstrm_item), "fstrm_item");
-	if (!item_zone)
-		return -ENOMEM;
-	return 0;
-}
-
-void
-xfs_filestream_uninit(void)
-{
-	kmem_zone_destroy(item_zone);
-}

fs/xfs/xfs_filestream.h

@@ -22,8 +22,6 @@ struct xfs_mount;
 struct xfs_inode;
 struct xfs_bmalloca;
 
-int xfs_filestream_init(void);
-void xfs_filestream_uninit(void);
 int xfs_filestream_mount(struct xfs_mount *mp);
 void xfs_filestream_unmount(struct xfs_mount *mp);
 void xfs_filestream_deassociate(struct xfs_inode *ip);

fs/xfs/xfs_super.c

@@ -1754,13 +1754,9 @@ init_xfs_fs(void)
 	if (error)
 		goto out_destroy_wq;
 
-	error = xfs_filestream_init();
-	if (error)
-		goto out_mru_cache_uninit;
-
 	error = xfs_buf_init();
 	if (error)
-		goto out_filestream_uninit;
+		goto out_mru_cache_uninit;
 
 	error = xfs_init_procfs();
 	if (error)
@@ -1787,8 +1783,6 @@ init_xfs_fs(void)
 	xfs_cleanup_procfs();
  out_buf_terminate:
 	xfs_buf_terminate();
- out_filestream_uninit:
-	xfs_filestream_uninit();
  out_mru_cache_uninit:
 	xfs_mru_cache_uninit();
  out_destroy_wq:
@@ -1807,7 +1801,6 @@ exit_xfs_fs(void)
 	xfs_sysctl_unregister();
 	xfs_cleanup_procfs();
 	xfs_buf_terminate();
-	xfs_filestream_uninit();
 	xfs_mru_cache_uninit();
 	xfs_destroy_workqueues();
 	xfs_destroy_zones();