1 files changed, 30 insertions, 1 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2c569b4d59d4..b69a46691a96 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1431,6 +1431,19 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
                 data = BTRFS_BLOCK_GROUP_MIXED;
         }
 
+        /* for SSD, cluster allocations together as much as possible */
+        if (btrfs_test_opt(root, SSD)) {
+                if (!data) {
+                        if (root->fs_info->last_alloc)
+                                hint_byte = root->fs_info->last_alloc;
+                        else {
+                                hint_byte = hint_byte &
+                                        ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
+                                empty_size += 16 * 1024 * 1024;
+                        }
+                }
+        }
+
         search_end = min(search_end,
                          btrfs_super_total_bytes(&info->super_copy));
         if (hint_byte) {
@@ -1456,6 +1469,19 @@ check_failed:
         }
         search_start = find_search_start(root, &block_group, search_start,
                                          total_needed, data);
+
+        if (!data && btrfs_test_opt(root, SSD) && info->last_alloc &&
+            search_start != info->last_alloc) {
+                info->last_alloc = 0;
+                if (!empty_size) {
+                        empty_size += 16 * 1024 * 1024;
+                        total_needed += empty_size;
+                }
+                search_start = find_search_start(root, &block_group,
+                                                 search_start, total_needed,
+                                                 data);
+        }
+
         search_start = stripe_align(root, search_start);
         cached_start = search_start;
         btrfs_init_path(path);
@@ -1610,6 +1636,8 @@ enospc:
 error:
         btrfs_release_path(root, path);
         btrfs_free_path(path);
+        if (btrfs_test_opt(root, SSD) && !ret && !data)
+                info->last_alloc = ins->objectid + ins->offset;
         return ret;
 }
 /*
@@ -1778,7 +1806,8 @@ struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                         buf->start, buf->start + buf->len - 1,
                         EXTENT_CSUM, GFP_NOFS);
         buf->flags |= EXTENT_CSUM;
-        btrfs_set_buffer_defrag(buf);
+        if (!btrfs_test_opt(root, SSD))
+                btrfs_set_buffer_defrag(buf);
         trans->blocks_used++;
         return buf;
 }