xfs: return maximum free size from xfs_rtany_summary()

Instead of only returning whether there is any free space, return the
maximum size, which is fast thanks to the previous commit. This will be
used by two upcoming optimizations.

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

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 6bde64584a37215c1f530040a33a3392330a93c5..c774a4ccdd150806da22069e54def0b4688e8f2b 100644 (file)
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -47,7 +47,7 @@ xfs_rtany_summary(
        int                     low,    /* low log2 extent size */
        int                     high,   /* high log2 extent size */
        xfs_fileoff_t           bbno,   /* bitmap block number */
-       int                     *stat)  /* out: any good extents here? */
+       int                     *maxlog) /* out: max log2 extent size free */
 {
        struct xfs_mount        *mp = args->mp;
        int                     error;
@@ -58,7 +58,7 @@ xfs_rtany_summary(
        if (mp->m_rsum_cache) {
                high = min(high, mp->m_rsum_cache[bbno] - 1);
                if (low > high) {
-                       *stat = 0;
+                       *maxlog = -1;
                        return 0;
                }
        }
@@ -78,14 +78,14 @@ xfs_rtany_summary(
                 * If there are any, return success.
                 */
                if (sum) {
-                       *stat = 1;
+                       *maxlog = log;
                        goto out;
                }
        }
        /*
         * Found nothing, return failure.
         */
-       *stat = 0;
+       *maxlog = -1;
 out:
        /* There were no extents at levels > log. */
        if (mp->m_rsum_cache && log + 1 < mp->m_rsum_cache[bbno])
@@ -434,7 +434,7 @@ xfs_rtallocate_extent_near(
        xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
 {
        struct xfs_mount        *mp = args->mp;
-       int                     any;    /* any useful extents from summary */
+       int                     maxlog; /* max useful extent from summary */
        xfs_fileoff_t           bbno;   /* bitmap block number */
        int                     error;
        int                     i;      /* bitmap block offset (loop control) */
@@ -488,7 +488,7 @@ xfs_rtallocate_extent_near(
                 * starting in this bitmap block.
                 */
                error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
-                               bbno + i, &any);
+                               bbno + i, &maxlog);
                if (error) {
                        return error;
                }
@@ -496,7 +496,7 @@ xfs_rtallocate_extent_near(
                 * If there are any useful extents starting here, try
                 * allocating one.
                 */
-               if (any) {
+               if (maxlog >= 0) {
                        /*
                         * On the positive side of the starting location.
                         */
@@ -537,7 +537,7 @@ xfs_rtallocate_extent_near(
                                        error = xfs_rtany_summary(args,
                                                        log2len,
                                                        mp->m_rsumlevels - 1,
-                                                       bbno + j, &any);
+                                                       bbno + j, &maxlog);
                                        if (error) {
                                                return error;
                                        }
@@ -549,7 +549,7 @@ xfs_rtallocate_extent_near(
                                         * extent given, we've already tried
                                         * that allocation, don't do it again.
                                         */
-                                       if (any)
+                                       if (maxlog >= 0)
                                                continue;
                                        error = xfs_rtallocate_extent_block(args,
                                                        bbno + j, minlen,