xfs: remove prev argument to xfs_bmapi_reserve_delalloc

We can easily lookup the previous extent for the cases where we need it,
which saves the callers from looking it up for us later in the series.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -4235,7 +4235,6 @@ xfs_bmapi_reserve_delalloc(
 	xfs_fileoff_t		aoff,
 	xfs_filblks_t		len,
 	struct xfs_bmbt_irec	*got,
-	struct xfs_bmbt_irec	*prev,
 	xfs_extnum_t		*lastx,
 	int			eof)
 {
@@ -4257,7 +4256,12 @@ xfs_bmapi_reserve_delalloc(
 	else
 		extsz = xfs_get_extsz_hint(ip);
 	if (extsz) {
-		error = xfs_bmap_extsize_align(mp, got, prev, extsz, rt, eof,
+		struct xfs_bmbt_irec	prev;
+
+		if (!xfs_iext_get_extent(ifp, *lastx - 1, &prev))
+			prev.br_startoff = NULLFILEOFF;
+
+		error = xfs_bmap_extsize_align(mp, got, &prev, extsz, rt, eof,
 					       1, 0, &aoff, &alen);
 		ASSERT(!error);
 	}

fs/xfs/libxfs/xfs_bmap.h

@@ -243,8 +243,7 @@ struct xfs_bmbt_rec_host *
 		struct xfs_bmbt_irec *gotp, struct xfs_bmbt_irec *prevp);
 int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
 		xfs_fileoff_t aoff, xfs_filblks_t len,
-		struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *prev,
-		xfs_extnum_t *lastx, int eof);
+		struct xfs_bmbt_irec *got, xfs_extnum_t *lastx, int eof);
 
 enum xfs_bmap_intent_type {
 	XFS_BMAP_MAP = 1,

fs/xfs/xfs_iomap.c

@@ -622,8 +622,7 @@ xfs_file_iomap_begin_delay(
 
 retry:
 	error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb,
-			end_fsb - offset_fsb, &got,
-			&prev, &idx, eof);
+			end_fsb - offset_fsb, &got, &idx, eof);
 	switch (error) {
 	case 0:
 		break;

fs/xfs/xfs_reflink.c

@@ -293,7 +293,7 @@ xfs_reflink_reserve_cow(
 
 retry:
 	error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff,
-			end_fsb - imap->br_startoff, &got, &prev, &idx, eof);
+			end_fsb - imap->br_startoff, &got, &idx, eof);
 	switch (error) {
 	case 0:
 		break;