Btrfs: Fix for lockdep warnings with alloc_mutex and pinned_mutex

This the lockdep complaint by having a different mutex to gaurd caching the
block group, so you don't end up with this backwards dependancy.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>

1 files changed, 18 insertions, 14 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b33e0bfb99e1..a970472eab17 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -170,8 +170,8 @@ static int add_new_free_space(struct btrfs_block_group_cache *block_group,
                         start = extent_end + 1;
                 } else if (extent_start > start && extent_start < end) {
                         size = extent_start - start;
-                        ret = btrfs_add_free_space_lock(block_group, start,
-                                                        size);
+                        ret = btrfs_add_free_space(block_group, start,
+                                                   size);
                         BUG_ON(ret);
                         start = extent_end + 1;
                 } else {
@@ -181,7 +181,7 @@ static int add_new_free_space(struct btrfs_block_group_cache *block_group,
 
         if (start < end) {
                 size = end - start;
-                ret = btrfs_add_free_space_lock(block_group, start, size);
+                ret = btrfs_add_free_space(block_group, start, size);
                 BUG_ON(ret);
         }
         mutex_unlock(&info->pinned_mutex);
@@ -2842,17 +2842,19 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
                 if (!block_group)
                         goto new_group_no_lock;
 
+                if (unlikely(!block_group->cached)) {
+                        mutex_lock(&block_group->cache_mutex);
+                        ret = cache_block_group(root, block_group);
+                        mutex_unlock(&block_group->cache_mutex);
+                        if (ret)
+                                break;
+                }
+
                 mutex_lock(&block_group->alloc_mutex);
                 if (unlikely(!block_group_bits(block_group, data)))
                         goto new_group;
 
-                ret = cache_block_group(root, block_group);
-                if (ret) {
-                        mutex_unlock(&block_group->alloc_mutex);
-                        break;
-                }
-
-                if (block_group->ro)
+                if (unlikely(block_group->ro))
                         goto new_group;
 
                 free_space = btrfs_find_free_space(block_group, search_start,
@@ -3273,12 +3275,12 @@ int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
         struct btrfs_block_group_cache *block_group;
 
         block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
-        mutex_lock(&block_group->alloc_mutex);
+        mutex_lock(&block_group->cache_mutex);
         cache_block_group(root, block_group);
+        mutex_unlock(&block_group->cache_mutex);
 
-        ret = btrfs_remove_free_space_lock(block_group, ins->objectid,
-                                           ins->offset);
-        mutex_unlock(&block_group->alloc_mutex);
+        ret = btrfs_remove_free_space(block_group, ins->objectid,
+                                      ins->offset);
         BUG_ON(ret);
         ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
                                             ref_generation, owner, ins);
@@ -5801,6 +5803,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 
                 spin_lock_init(&cache->lock);
                 mutex_init(&cache->alloc_mutex);
+                mutex_init(&cache->cache_mutex);
                 INIT_LIST_HEAD(&cache->list);
                 read_extent_buffer(leaf, &cache->item,
                                    btrfs_item_ptr_offset(leaf, path->slots[0]),
@@ -5854,6 +5857,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
         cache->key.offset = size;
         spin_lock_init(&cache->lock);
         mutex_init(&cache->alloc_mutex);
+        mutex_init(&cache->cache_mutex);
         INIT_LIST_HEAD(&cache->list);
         btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);