[PATCH 36/64] xfs: add a xefi_entry helper

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Christoph Hellwig <hch@xxxxxx>

Source kernel commit: 649c0c2b86ee944a1a9962b310b1b97ead12e97a

Add a helper to translate from the item list head to the
xfs_extent_free_item structure and use it so shorten assignments
and avoid the need for extra local variables.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 libxfs/defer_item.c |   24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)


diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
index fb40a6625..8cb27912f 100644
--- a/libxfs/defer_item.c
+++ b/libxfs/defer_item.c
@@ -32,6 +32,11 @@
 
 /* Extent Freeing */
 
+static inline struct xfs_extent_free_item *xefi_entry(const struct list_head *e)
+{
+	return list_entry(e, struct xfs_extent_free_item, xefi_list);
+}
+
 /* Sort bmap items by AG. */
 static int
 xfs_extent_free_diff_items(
@@ -39,11 +44,8 @@ xfs_extent_free_diff_items(
 	const struct list_head		*a,
 	const struct list_head		*b)
 {
-	const struct xfs_extent_free_item *ra;
-	const struct xfs_extent_free_item *rb;
-
-	ra = container_of(a, struct xfs_extent_free_item, xefi_list);
-	rb = container_of(b, struct xfs_extent_free_item, xefi_list);
+	struct xfs_extent_free_item	*ra = xefi_entry(a);
+	struct xfs_extent_free_item	*rb = xefi_entry(b);
 
 	return ra->xefi_pag->pag_agno - rb->xefi_pag->pag_agno;
 }
@@ -99,12 +101,10 @@ xfs_extent_free_finish_item(
 	struct xfs_btree_cur		**state)
 {
 	struct xfs_owner_info		oinfo = { };
-	struct xfs_extent_free_item	*xefi;
+	struct xfs_extent_free_item	*xefi = xefi_entry(item);
 	xfs_agblock_t			agbno;
 	int				error = 0;
 
-	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
-
 	oinfo.oi_owner = xefi->xefi_owner;
 	if (xefi->xefi_flags & XFS_EFI_ATTR_FORK)
 		oinfo.oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
@@ -143,9 +143,7 @@ STATIC void
 xfs_extent_free_cancel_item(
 	struct list_head		*item)
 {
-	struct xfs_extent_free_item	*xefi;
-
-	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
+	struct xfs_extent_free_item	*xefi = xefi_entry(item);
 
 	xfs_extent_free_put_group(xefi);
 	kmem_cache_free(xfs_extfree_item_cache, xefi);
@@ -173,13 +171,11 @@ xfs_agfl_free_finish_item(
 {
 	struct xfs_owner_info		oinfo = { };
 	struct xfs_mount		*mp = tp->t_mountp;
-	struct xfs_extent_free_item	*xefi;
+	struct xfs_extent_free_item	*xefi = xefi_entry(item);
 	struct xfs_buf			*agbp;
 	int				error;
 	xfs_agblock_t			agbno;
 
-	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
-
 	ASSERT(xefi->xefi_blockcount == 1);
 	agbno = XFS_FSB_TO_AGBNO(mp, xefi->xefi_startblock);
 	oinfo.oi_owner = xefi->xefi_owner;