xfs: add a bi_entry helper

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@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index d8601247ec8c5d40924614b9b18b8d1e54624417..eb56dc5aae74dd73ac7f7864e1c73c137aef664d 100644 (file)
--- a/fs/xfs/xfs_bmap_item.c
+++ b/fs/xfs/xfs_bmap_item.c
@@ -221,6 +221,11 @@ static const struct xfs_item_ops xfs_bud_item_ops = {
        .iop_intent     = xfs_bud_item_intent,
 };
 
+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(
@@ -228,11 +233,9 @@ xfs_bmap_update_diff_items(
        const struct list_head          *a,
        const struct list_head          *b)
 {
-       struct xfs_bmap_intent          *ba;
-       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;
 }
 
@@ -348,11 +351,9 @@ 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);
@@ -377,9 +378,7 @@ 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);