xfs: add a xefi_entry helper

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

diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
index fb40a66252adff0202318c9bdd2df68045a50731..8cb27912fb3e8c9fb5a0303fa7782a56f2823ef3 100644 (file)
--- 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;