xfs: factor out a xfs_rtalloc_sumlevel helper

xfs_rtallocate_extent_size has two loops with nearly identical logic
in them.  Split that logic into a separate xfs_rtalloc_sumlevel helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 00083013a01034f4014206c80d0a0f2ca27e68c4..cd183d050fd2ee5af761d4560ac1616f767d5cb0 100644 (file)
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -538,6 +538,52 @@ xfs_rtallocate_extent_near(
        return -ENOSPC;
 }
 
+static int
+xfs_rtalloc_sumlevel(
+       struct xfs_rtalloc_args *args,
+       int                     l,      /* level number */
+       xfs_rtxlen_t            minlen, /* minimum length to allocate */
+       xfs_rtxlen_t            maxlen, /* maximum length to allocate */
+       xfs_rtxlen_t            prod,   /* extent product factor */
+       xfs_rtxlen_t            *len,   /* out: actual length allocated */
+       xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
+{
+       xfs_fileoff_t           i;      /* bitmap block number */
+
+       for (i = 0; i < args->mp->m_sb.sb_rbmblocks; i++) {
+               xfs_suminfo_t   sum;    /* summary information for extents */
+               xfs_rtxnum_t    n;      /* next rtext to be tried */
+               int             error;
+
+               error = xfs_rtget_summary(args, l, i, &sum);
+               if (error)
+                       return error;
+
+               /*
+                * Nothing there, on to the next block.
+                */
+               if (!sum)
+                       continue;
+
+               /*
+                * Try allocating the extent.
+                */
+               error = xfs_rtallocate_extent_block(args, i, minlen, maxlen,
+                               len, &n, prod, rtx);
+               if (error != -ENOSPC)
+                       return error;
+
+               /*
+                * If the "next block to try" returned from the allocator is
+                * beyond the next bitmap block, skip to that bitmap block.
+                */
+               if (xfs_rtx_to_rbmblock(args->mp, n) > i + 1)
+                       i = xfs_rtx_to_rbmblock(args->mp, n) - 1;
+       }
+
+       return -ENOSPC;
+}
+
 /*
  * Allocate an extent of length minlen<=len<=maxlen, with no position
  * specified.  If we don't get maxlen then use prod to trim
@@ -552,12 +598,8 @@ xfs_rtallocate_extent_size(
        xfs_rtxlen_t            prod,   /* extent product factor */
        xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
 {
-       struct xfs_mount        *mp = args->mp;
        int                     error;
-       xfs_fileoff_t           i;      /* bitmap block number */
        int                     l;      /* level number (loop control) */
-       xfs_rtxnum_t            n;      /* next rtext to be tried */
-       xfs_suminfo_t           sum;    /* summary information for extents */
 
        ASSERT(minlen % prod == 0);
        ASSERT(maxlen % prod == 0);
@@ -565,46 +607,23 @@ xfs_rtallocate_extent_size(
 
        /*
         * Loop over all the levels starting with maxlen.
-        * At each level, look at all the bitmap blocks, to see if there
-        * are extents starting there that are long enough (>= maxlen).
-        * Note, only on the initial level can the allocation fail if
-        * the summary says there's an extent.
+        *
+        * At each level, look at all the bitmap blocks, to see if there are
+        * extents starting there that are long enough (>= maxlen).
+        *
+        * Note, only on the initial level can the allocation fail if the
+        * summary says there's an extent.
         */
-       for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
-               /*
-                * Loop over all the bitmap blocks.
-                */
-               for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
-                       /*
-                        * Get the summary for this level/block.
-                        */
-                       error = xfs_rtget_summary(args, l, i, &sum);
-                       if (error)
-                               return error;
-                       /*
-                        * Nothing there, on to the next block.
-                        */
-                       if (!sum)
-                               continue;
-                       /*
-                        * Try allocating the extent.
-                        */
-                       error = xfs_rtallocate_extent_block(args, i, maxlen,
-                                       maxlen, len, &n, prod, rtx);
-                       if (error != -ENOSPC)
-                               return error;
-                       /*
-                        * If the "next block to try" returned from the
-                        * allocator is beyond the next bitmap block,
-                        * skip to that bitmap block.
-                        */
-                       if (xfs_rtx_to_rbmblock(mp, n) > i + 1)
-                               i = xfs_rtx_to_rbmblock(mp, n) - 1;
-               }
+       for (l = xfs_highbit32(maxlen); l < args->mp->m_rsumlevels; l++) {
+               error = xfs_rtalloc_sumlevel(args, l, minlen, maxlen, prod, len,
+                               rtx);
+               if (error != -ENOSPC)
+                       return error;
        }
+
        /*
-        * Didn't find any maxlen blocks.  Try smaller ones, unless
-        * we're asking for a fixed size extent.
+        * Didn't find any maxlen blocks.  Try smaller ones, unless we are
+        * looking for a fixed size extent.
         */
        if (minlen > --maxlen)
                return -ENOSPC;
@@ -613,51 +632,19 @@ xfs_rtallocate_extent_size(
 
        /*
         * Loop over sizes, from maxlen down to minlen.
-        * This time, when we do the allocations, allow smaller ones
-        * to succeed.
+        *
+        * This time, when we do the allocations, allow smaller ones to succeed,
+        * but make sure the specified minlen/maxlen are in the possible range
+        * for this summary level.
         */
        for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
-               /*
-                * Loop over all the bitmap blocks, try an allocation
-                * starting in that block.
-                */
-               for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
-                       /*
-                        * Get the summary information for this level/block.
-                        */
-                       error = xfs_rtget_summary(args, l, i, &sum);
-                       if (error)
-                               return error;
-
-                       /*
-                        * If nothing there, go on to next.
-                        */
-                       if (!sum)
-                               continue;
-                       /*
-                        * Try the allocation.  Make sure the specified
-                        * minlen/maxlen are in the possible range for
-                        * this summary level.
-                        */
-                       error = xfs_rtallocate_extent_block(args, i,
-                                       XFS_RTMAX(minlen, 1 << l),
-                                       XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
-                                       len, &n, prod, rtx);
-                       if (error != -ENOSPC)
-                               return error;
-
-                       /*
-                        * If the "next block to try" returned from the
-                        * allocator is beyond the next bitmap block,
-                        * skip to that bitmap block.
-                        */
-                       if (xfs_rtx_to_rbmblock(mp, n) > i + 1)
-                               i = xfs_rtx_to_rbmblock(mp, n) - 1;
-               }
+               error = xfs_rtalloc_sumlevel(args, l, XFS_RTMAX(minlen, 1 << l),
+                               XFS_RTMIN(maxlen, (1 << (l + 1)) - 1), prod,
+                               len, rtx);
+               if (error != -ENOSPC)
+                       return error;
        }
-       /*
-        * Got nothing, return failure.
-        */
+
        return -ENOSPC;
 }