xfs: factor out code to find the longest free extent in the AG

Signed-off-by: Dave Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 21 insertions, 5 deletions

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 028e44e58ea..2cf944eb796 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -1872,6 +1872,25 @@ xfs_alloc_compute_maxlevels(
 }
 
 /*
+ * Find the length of the longest extent in an AG.
+ */
+xfs_extlen_t
+xfs_alloc_longest_free_extent(
+        struct xfs_mount        *mp,
+        struct xfs_perag        *pag)
+{
+        xfs_extlen_t            need, delta = 0;
+
+        need = XFS_MIN_FREELIST_PAG(pag, mp);
+        if (need > pag->pagf_flcount)
+                delta = need - pag->pagf_flcount;
+
+        if (pag->pagf_longest > delta)
+                return pag->pagf_longest - delta;
+        return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
+}
+
+/*
  * Decide whether to use this allocation group for this allocation.
  * If so, fix up the btree freelist's size.
  */
@@ -1923,15 +1942,12 @@ xfs_alloc_fix_freelist(
         }
 
         if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
-                need = XFS_MIN_FREELIST_PAG(pag, mp);
-                delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
                 /*
                  * If it looks like there isn't a long enough extent, or enough
                  * total blocks, reject it.
                  */
-                longest = (pag->pagf_longest > delta) ?
-                        (pag->pagf_longest - delta) :
-                        (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
+                need = XFS_MIN_FREELIST_PAG(pag, mp);
+                longest = xfs_alloc_longest_free_extent(mp, pag);
                 if ((args->minlen + args->alignment + args->minalignslop - 1) >
                                 longest ||
                     ((int)(pag->pagf_freeblks + pag->pagf_flcount -