1 files changed, 35 insertions, 6 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 059dfa048cc..a3e71b59f66 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6728,6 +6728,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
         struct btrfs_space_info *space_info;
         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
         struct btrfs_device *device;
+        u64 min_free;
+        int index;
+        int dev_nr = 0;
+        int dev_min = 1;
         int full = 0;
         int ret = 0;
 
@@ -6737,8 +6741,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
         if (!block_group)
                 return -1;
 
+        min_free = btrfs_block_group_used(&block_group->item);
+
         /* no bytes used, we're good */
-        if (!btrfs_block_group_used(&block_group->item))
+        if (!min_free)
                 goto out;
 
         space_info = block_group->space_info;
@@ -6754,10 +6760,9 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
          * all of the extents from this block group.  If we can, we're good
          */
         if ((space_info->total_bytes != block_group->key.offset) &&
-           (space_info->bytes_used + space_info->bytes_reserved +
-            space_info->bytes_pinned + space_info->bytes_readonly +
-            btrfs_block_group_used(&block_group->item) <
-            space_info->total_bytes)) {
+            (space_info->bytes_used + space_info->bytes_reserved +
+             space_info->bytes_pinned + space_info->bytes_readonly +
+             min_free < space_info->total_bytes)) {
                 spin_unlock(&space_info->lock);
                 goto out;
         }
@@ -6774,9 +6779,29 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
         if (full)
                 goto out;
 
+        /*
+         * index:
+         *      0: raid10
+         *      1: raid1
+         *      2: dup
+         *      3: raid0
+         *      4: single
+         */
+        index = get_block_group_index(block_group);
+        if (index == 0) {
+                dev_min = 4;
+                min_free /= 2;
+        } else if (index == 1) {
+                dev_min = 2;
+        } else if (index == 2) {
+                min_free *= 2;
+        } else if (index == 3) {
+                dev_min = fs_devices->rw_devices;
+                min_free /= dev_min;
+        }
+
         mutex_lock(&root->fs_info->chunk_mutex);
         list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
-                u64 min_free = btrfs_block_group_used(&block_group->item);
                 u64 dev_offset;
 
                 /*
@@ -6787,7 +6812,11 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                         ret = find_free_dev_extent(NULL, device, min_free,
                                                    &dev_offset, NULL);
                         if (!ret)
+                                dev_nr++;
+
+                        if (dev_nr >= dev_min)
                                 break;
+
                         ret = -1;
                 }
         }