[XFS] Use the generic bitops rather than implementing them ourselves.

This keeps xfs_lowbit64 as it was since there aren't good generic helpers
there ... Patch inspired by Andi Kleen.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31472a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 7 insertions, 12 deletions

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index bf87a5913504..e2f68de16159 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -74,18 +74,6 @@ STATIC int xfs_rtmodify_summary(xfs_mount_t *, xfs_trans_t *, int,
  */
 
 /*
- * xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set.
- */
-STATIC int
-xfs_lowbit32(
-        __uint32_t      v)
-{
-        if (v)
-                return ffs(v) - 1;
-        return -1;
-}
-
-/*
  * Allocate space to the bitmap or summary file, and zero it, for growfs.
  */
 STATIC int                              /* error */
@@ -450,6 +438,7 @@ xfs_rtallocate_extent_near(
         }
         bbno = XFS_BITTOBLOCK(mp, bno);
         i = 0;
+        ASSERT(minlen != 0);
         log2len = xfs_highbit32(minlen);
         /*
          * Loop over all bitmap blocks (bbno + i is current block).
@@ -618,6 +607,8 @@ xfs_rtallocate_extent_size(
         xfs_suminfo_t   sum;            /* summary information for extents */
 
         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
+        ASSERT(maxlen != 0);
+
         /*
          * Loop over all the levels starting with maxlen.
          * At each level, look at all the bitmap blocks, to see if there
@@ -675,6 +666,9 @@ xfs_rtallocate_extent_size(
                 *rtblock = NULLRTBLOCK;
                 return 0;
         }
+        ASSERT(minlen != 0);
+        ASSERT(maxlen != 0);
+
         /*
          * Loop over sizes, from maxlen down to minlen.
          * This time, when we do the allocations, allow smaller ones
@@ -1961,6 +1955,7 @@ xfs_growfs_rt(
                                   nsbp->sb_blocksize * nsbp->sb_rextsize);
                 nsbp->sb_rextents = nsbp->sb_rblocks;
                 do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
+                ASSERT(nsbp->sb_rextents != 0);
                 nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
                 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
                 nrsumsize =