[PATCH 2/4] libxfs: add a bi_entry helper

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

From: Darrick J. Wong <djwong@xxxxxxxxxx>

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

Inspired-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
 libxfs/defer_item.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)


diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
index 680a72664..d19322a0b 100644
--- a/libxfs/defer_item.c
+++ b/libxfs/defer_item.c
@@ -439,6 +439,11 @@ const struct xfs_defer_op_type xfs_refcount_update_defer_type = {
 
 /* Inode Block Mapping */
 
+static inline struct xfs_bmap_intent *bi_entry(const struct list_head *e)
+{
+	return list_entry(e, struct xfs_bmap_intent, bi_list);
+}
+
 /* Sort bmap intents by inode. */
 static int
 xfs_bmap_update_diff_items(
@@ -446,11 +451,9 @@ xfs_bmap_update_diff_items(
 	const struct list_head		*a,
 	const struct list_head		*b)
 {
-	const struct xfs_bmap_intent	*ba;
-	const struct xfs_bmap_intent	*bb;
+	struct xfs_bmap_intent		*ba = bi_entry(a);
+	struct xfs_bmap_intent		*bb = bi_entry(b);
 
-	ba = container_of(a, struct xfs_bmap_intent, bi_list);
-	bb = container_of(b, struct xfs_bmap_intent, bi_list);
 	return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
 }
 
@@ -527,10 +530,9 @@ xfs_bmap_update_finish_item(
 	struct list_head		*item,
 	struct xfs_btree_cur		**state)
 {
-	struct xfs_bmap_intent		*bi;
+	struct xfs_bmap_intent		*bi = bi_entry(item);
 	int				error;
 
-	bi = container_of(item, struct xfs_bmap_intent, bi_list);
 	error = xfs_bmap_finish_one(tp, bi);
 	if (!error && bi->bi_bmap.br_blockcount > 0) {
 		ASSERT(bi->bi_type == XFS_BMAP_UNMAP);
@@ -554,9 +556,7 @@ STATIC void
 xfs_bmap_update_cancel_item(
 	struct list_head		*item)
 {
-	struct xfs_bmap_intent		*bi;
-
-	bi = container_of(item, struct xfs_bmap_intent, bi_list);
+	struct xfs_bmap_intent		*bi = bi_entry(item);
 
 	xfs_bmap_update_put_group(bi);
 	kmem_cache_free(xfs_bmap_intent_cache, bi);