xfs: make the rtalloc start hint a xfs_rtblock_t

0 is a valid start RT extent, and with pending changes it will become
both more common and non-unique.  Switch to pass a xfs_rtblock_t instead
so that we can use NULLRTBLOCK to determine if a hint was set or not.

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/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 61e0c5b7a327d99558355e8c12e957753f24579e..29edb8044b00767932d1ca90bbe58de10bd5aa72 100644 (file)
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1266,7 +1266,7 @@ xfs_rtalloc_align_minmax(
 static int
 xfs_rtallocate(
        struct xfs_trans        *tp,
-       xfs_rtxnum_t            start,
+       xfs_rtblock_t           bno_hint,
        xfs_rtxlen_t            minlen,
        xfs_rtxlen_t            maxlen,
        xfs_rtxlen_t            prod,
@@ -1280,6 +1280,7 @@ xfs_rtallocate(
                .mp             = tp->t_mountp,
                .tp             = tp,
        };
+       xfs_rtxnum_t            start = 0;
        xfs_rtxnum_t            rtx;
        xfs_rtxlen_t            len = 0;
        int                     error = 0;
@@ -1297,7 +1298,9 @@ xfs_rtallocate(
         * For an allocation to an empty file at offset 0, pick an extent that
         * will space things out in the rt area.
         */
-       if (!start && initial_user_data)
+       if (bno_hint)
+               start = xfs_rtb_to_rtx(args.mp, bno_hint);
+       else if (initial_user_data)
                start = xfs_rtpick_extent(args.mp, tp, maxlen);
 
        if (start) {
@@ -1410,15 +1413,16 @@ int
 xfs_bmap_rtalloc(
        struct xfs_bmalloca     *ap)
 {
-       struct xfs_mount        *mp = ap->ip->i_mount;
        xfs_fileoff_t           orig_offset = ap->offset;
-       xfs_rtxnum_t            start = 0; /* allocation hint rtextent no */
        xfs_rtxlen_t            prod = 0;  /* product factor for allocators */
        xfs_rtxlen_t            ralen = 0; /* realtime allocation length */
+       xfs_rtblock_t           bno_hint = NULLRTBLOCK;
        xfs_extlen_t            orig_length = ap->length;
        xfs_rtxlen_t            raminlen;
        bool                    rtlocked = false;
        bool                    noalign = false;
+       bool                    initial_user_data =
+               ap->datatype & XFS_ALLOC_INITIAL_USER_DATA;
        int                     error;
 
 retry:
@@ -1427,10 +1431,10 @@ retry:
                return error;
 
        if (xfs_bmap_adjacent(ap))
-               start = xfs_rtb_to_rtx(mp, ap->blkno);
+               bno_hint = ap->blkno;
 
-       error = xfs_rtallocate(ap->tp, start, raminlen, ralen, prod, ap->wasdel,
-                       ap->datatype & XFS_ALLOC_INITIAL_USER_DATA, &rtlocked,
+       error = xfs_rtallocate(ap->tp, bno_hint, raminlen, ralen, prod,
+                       ap->wasdel, initial_user_data, &rtlocked,
                        &ap->blkno, &ap->length);
        if (error == -ENOSPC) {
                if (!noalign) {