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>

4 files changed, 31 insertions, 22 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 -
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h
index 588172796f7..e704caee10d 100644
--- a/fs/xfs/xfs_alloc.h
+++ b/fs/xfs/xfs_alloc.h
@@ -100,6 +100,12 @@ typedef struct xfs_alloc_arg {
 #define XFS_ALLOC_USERDATA              1       /* allocation is for user data*/
 #define XFS_ALLOC_INITIAL_USER_DATA     2       /* special case start of file */
 
+/*
+ * 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);
 
 #ifdef __KERNEL__
 
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 27062d0a879..07b7d0d59d8 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2712,9 +2712,6 @@ xfs_bmap_btalloc(
         xfs_agnumber_t  startag;
         xfs_alloc_arg_t args;
         xfs_extlen_t    blen;
-        xfs_extlen_t    delta;
-        xfs_extlen_t    longest;
-        xfs_extlen_t    need;
         xfs_extlen_t    nextminlen = 0;
         xfs_perag_t     *pag;
         int             nullfb;         /* true if ap->firstblock isn't set */
@@ -2796,13 +2793,8 @@ xfs_bmap_btalloc(
                          * See xfs_alloc_fix_freelist...
                          */
                         if (pag->pagf_init) {
-                                need = XFS_MIN_FREELIST_PAG(pag, mp);
-                                delta = need > pag->pagf_flcount ?
-                                        need - pag->pagf_flcount : 0;
-                                longest = (pag->pagf_longest > delta) ?
-                                        (pag->pagf_longest - delta) :
-                                        (pag->pagf_flcount > 0 ||
-                                         pag->pagf_longest > 0);
+                                xfs_extlen_t    longest;
+                                longest = xfs_alloc_longest_free_extent(mp, pag);
                                 if (blen < longest)
                                         blen = longest;
                         } else
diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index f3bb75da384..6c87c8f304e 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -140,7 +140,7 @@ _xfs_filestream_pick_ag(
         xfs_extlen_t    minlen)
 {
         int             err, trylock, nscan;
-        xfs_extlen_t    delta, longest, need, free, minfree, maxfree = 0;
+        xfs_extlen_t    longest, free, minfree, maxfree = 0;
         xfs_agnumber_t  ag, max_ag = NULLAGNUMBER;
         struct xfs_perag *pag;
 
@@ -186,12 +186,7 @@ _xfs_filestream_pick_ag(
                         goto next_ag;
                 }
 
-                need = XFS_MIN_FREELIST_PAG(pag, mp);
-                delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
-                longest = (pag->pagf_longest > delta) ?
-                          (pag->pagf_longest - delta) :
-                          (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
-
+                longest = xfs_alloc_longest_free_extent(mp, pag);
                 if (((minlen && longest >= minlen) ||
                      (!minlen && pag->pagf_freeblks >= minfree)) &&
                     (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||