1 files changed, 18 insertions, 6 deletions

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 5673bcfda2f0..71596e57283a 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -175,6 +175,7 @@ xfs_alloc_compute_diff(
         xfs_agblock_t   wantbno,        /* target starting block */
         xfs_extlen_t    wantlen,        /* target length */
         xfs_extlen_t    alignment,      /* target alignment */
+        char            userdata,       /* are we allocating data? */
         xfs_agblock_t   freebno,        /* freespace's starting block */
         xfs_extlen_t    freelen,        /* freespace's length */
         xfs_agblock_t   *newbnop)       /* result: best start block from free */
@@ -189,7 +190,14 @@ xfs_alloc_compute_diff(
         ASSERT(freelen >= wantlen);
         freeend = freebno + freelen;
         wantend = wantbno + wantlen;
-        if (freebno >= wantbno) {
+        /*
+         * We want to allocate from the start of a free extent if it is past
+         * the desired block or if we are allocating user data and the free
+         * extent is before desired block. The second case is there to allow
+         * for contiguous allocation from the remaining free space if the file
+         * grows in the short term.
+         */
+        if (freebno >= wantbno || (userdata && freeend < wantend)) {
                 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
                         newbno1 = NULLAGBLOCK;
         } else if (freeend >= wantend && alignment > 1) {
@@ -805,7 +813,8 @@ xfs_alloc_find_best_extent(
                         xfs_alloc_fix_len(args);
 
                         sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
-                                                       args->alignment, *sbnoa,
+                                                       args->alignment,
+                                                       args->userdata, *sbnoa,
                                                        *slena, &new);
 
                         /*
@@ -976,7 +985,8 @@ restart:
                         if (args->len < blen)
                                 continue;
                         ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
-                                args->alignment, ltbnoa, ltlena, &ltnew);
+                                args->alignment, args->userdata, ltbnoa,
+                                ltlena, &ltnew);
                         if (ltnew != NULLAGBLOCK &&
                             (args->len > blen || ltdiff < bdiff)) {
                                 bdiff = ltdiff;
@@ -1128,7 +1138,8 @@ restart:
                         args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
                         xfs_alloc_fix_len(args);
                         ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
-                                args->alignment, ltbnoa, ltlena, &ltnew);
+                                args->alignment, args->userdata, ltbnoa,
+                                ltlena, &ltnew);
 
                         error = xfs_alloc_find_best_extent(args,
                                                 &bno_cur_lt, &bno_cur_gt,
@@ -1144,7 +1155,8 @@ restart:
                         args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
                         xfs_alloc_fix_len(args);
                         gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
-                                args->alignment, gtbnoa, gtlena, &gtnew);
+                                args->alignment, args->userdata, gtbnoa,
+                                gtlena, &gtnew);
 
                         error = xfs_alloc_find_best_extent(args,
                                                 &bno_cur_gt, &bno_cur_lt,
@@ -1203,7 +1215,7 @@ restart:
         }
         rlen = args->len;
         (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
-                                     ltbnoa, ltlena, &ltnew);
+                                     args->userdata, ltbnoa, ltlena, &ltnew);
         ASSERT(ltnew >= ltbno);
         ASSERT(ltnew + rlen <= ltbnoa + ltlena);
         ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));