Btrfs: fix cluster alignment for mount -o ssd

With the new raid56 code, we want to make sure we're
properly aligning our allocation clusters with -o ssd

Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3345f68fc64b..f13402104c96 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5715,6 +5715,7 @@ have_block_group:
                  * lets look there
                  */
                 if (last_ptr) {
+                        unsigned long aligned_cluster;
                         /*
                          * the refill lock keeps out other
                          * people trying to start a new cluster
@@ -5781,11 +5782,15 @@ refill_cluster:
                                 goto unclustered_alloc;
                         }
 
+                        aligned_cluster = max_t(unsigned long,
+                                                empty_cluster + empty_size,
+                                              block_group->full_stripe_len);
+
                         /* allocate a cluster in this block group */
                         ret = btrfs_find_space_cluster(trans, root,
                                                block_group, last_ptr,
                                                search_start, num_bytes,
-                                               empty_cluster + empty_size);
+                                               aligned_cluster);
                         if (ret == 0) {
                                 /*
                                  * now pull our allocation out of this