Merge branch 'for-chris-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.4

5 files changed, 10 insertions, 8 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4b89680a1923..c4661db2b72a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10480,11 +10480,15 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
                  * until transaction commit to do the actual discard.
                  */
                 if (trimming) {
-                        WARN_ON(!list_empty(&block_group->bg_list));
-                        spin_lock(&trans->transaction->deleted_bgs_lock);
+                        spin_lock(&fs_info->unused_bgs_lock);
+                        /*
+                         * A concurrent scrub might have added us to the list
+                         * fs_info->unused_bgs, so use a list_move operation
+                         * to add the block group to the deleted_bgs list.
+                         */
                         list_move(&block_group->bg_list,
                                   &trans->transaction->deleted_bgs);
-                        spin_unlock(&trans->transaction->deleted_bgs_lock);
+                        spin_unlock(&fs_info->unused_bgs_lock);
                         btrfs_get_block_group(block_group);
                 }
 end_trans:
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index e6fc7d9e65b1..f331ef7d573a 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -891,7 +891,7 @@ out:
                 spin_unlock(&block_group->lock);
                 ret = 0;
 
-                btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuild it now",
+                btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuilding it now",
                         block_group->key.objectid);
         }
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3367a3c6f214..be8eae80ff65 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -274,7 +274,6 @@ loop:
         cur_trans->num_dirty_bgs = 0;
         spin_lock_init(&cur_trans->dirty_bgs_lock);
         INIT_LIST_HEAD(&cur_trans->deleted_bgs);
-        spin_lock_init(&cur_trans->deleted_bgs_lock);
         spin_lock_init(&cur_trans->dropped_roots_lock);
         list_add_tail(&cur_trans->list, &fs_info->trans_list);
         extent_io_tree_init(&cur_trans->dirty_pages,
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 0da21ca9b3fb..64c8221b6165 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -77,8 +77,8 @@ struct btrfs_transaction {
          */
         struct mutex cache_write_mutex;
         spinlock_t dirty_bgs_lock;
+        /* Protected by spin lock fs_info->unused_bgs_lock. */
         struct list_head deleted_bgs;
-        spinlock_t deleted_bgs_lock;
         spinlock_t dropped_roots_lock;
         struct btrfs_delayed_ref_root delayed_refs;
         int aborted;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 750285e4f274..86124cde907a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3548,12 +3548,11 @@ again:
 
                         ret = btrfs_force_chunk_alloc(trans, chunk_root,
                                                       BTRFS_BLOCK_GROUP_DATA);
+                        btrfs_end_transaction(trans, chunk_root);
                         if (ret < 0) {
                                 mutex_unlock(&fs_info->delete_unused_bgs_mutex);
                                 goto error;
                         }
-
-                        btrfs_end_transaction(trans, chunk_root);
                         chunk_reserved = 1;
                 }