xfs: introduce the xfs_iext_cursor abstraction

Add a new xfs_iext_cursor structure to hide the direct extent map
index manipulations. In addition to the existing lookup/get/insert/
remove and update routines new primitives to get the first and last
extent cursor, as well as moving up and down by one extent are
provided.  Also new are convenience to increment/decrement the
cursor and retreive the new extent, as well as to peek into the
previous/next extent without updating the cursor and last but not
least a macro to iterate over all extents in a fork.

[darrick: rename for_each_iext to for_each_xfs_iext]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index cd82429d8df7..8338b894d54f 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -703,7 +703,7 @@ xfs_dq_get_next_id(
 	xfs_dqid_t		next_id = *id + 1; /* simple advance */
 	uint			lock_flags;
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	cur;
 	xfs_fsblock_t		start;
 	int			error = 0;
 
@@ -727,7 +727,7 @@ xfs_dq_get_next_id(
 			return error;
 	}
 
-	if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &idx, &got)) {
+	if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &cur, &got)) {
 		/* contiguous chunk, bump startoff for the id calculation */
 		if (got.br_startoff < start)
 			got.br_startoff = start;