Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index e52da6fb11659e3b1b893086581b7c5a85d8eeb6..9250b9c4f01e1b826e25414e6ace942487e2ccca 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1052,7 +1052,12 @@ int btrfs_defrag_root(struct btrfs_root *root)
 
 /*
  * new snapshots need to be created at a very specific time in the
- * transaction commit.  This does the actual creation
+ * transaction commit.  This does the actual creation.
+ *
+ * Note:
+ * If the error which may affect the commitment of the current transaction
+ * happens, we should return the error number. If the error which just affect
+ * the creation of the pending snapshots, just return 0.
  */
 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                                   struct btrfs_fs_info *fs_info,
@@ -1071,7 +1076,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        struct extent_buffer *tmp;
        struct extent_buffer *old;
        struct timespec cur_time = CURRENT_TIME;
-       int ret;
+       int ret = 0;
        u64 to_reserve = 0;
        u64 index = 0;
        u64 objectid;
@@ -1080,40 +1085,36 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 
        path = btrfs_alloc_path();
        if (!path) {
-               ret = pending->error = -ENOMEM;
-               return ret;
+               pending->error = -ENOMEM;
+               return 0;
        }
 
        new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
        if (!new_root_item) {
-               ret = pending->error = -ENOMEM;
+               pending->error = -ENOMEM;
                goto root_item_alloc_fail;
        }
 
-       ret = btrfs_find_free_objectid(tree_root, &objectid);
-       if (ret) {
-               pending->error = ret;
+       pending->error = btrfs_find_free_objectid(tree_root, &objectid);
+       if (pending->error)
                goto no_free_objectid;
-       }
 
        btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
 
        if (to_reserve > 0) {
-               ret = btrfs_block_rsv_add(root, &pending->block_rsv,
-                                         to_reserve,
-                                         BTRFS_RESERVE_NO_FLUSH);
-               if (ret) {
-                       pending->error = ret;
+               pending->error = btrfs_block_rsv_add(root,
+                                                    &pending->block_rsv,
+                                                    to_reserve,
+                                                    BTRFS_RESERVE_NO_FLUSH);
+               if (pending->error)
                        goto no_free_objectid;
-               }
        }
 
-       ret = btrfs_qgroup_inherit(trans, fs_info, root->root_key.objectid,
-                                  objectid, pending->inherit);
-       if (ret) {
-               pending->error = ret;
+       pending->error = btrfs_qgroup_inherit(trans, fs_info,
+                                             root->root_key.objectid,
+                                             objectid, pending->inherit);
+       if (pending->error)
                goto no_free_objectid;
-       }
 
        key.objectid = objectid;
        key.offset = (u64)-1;
@@ -1141,7 +1142,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                                         dentry->d_name.len, 0);
        if (dir_item != NULL && !IS_ERR(dir_item)) {
                pending->error = -EEXIST;
-               goto fail;
+               goto dir_item_existed;
        } else if (IS_ERR(dir_item)) {
                ret = PTR_ERR(dir_item);
                btrfs_abort_transaction(trans, root, ret);
@@ -1272,6 +1273,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        if (ret)
                btrfs_abort_transaction(trans, root, ret);
 fail:
+       pending->error = ret;
+dir_item_existed:
        trans->block_rsv = rsv;
        trans->bytes_reserved = 0;
 no_free_objectid:
@@ -1287,12 +1290,17 @@ root_item_alloc_fail:
 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
                                             struct btrfs_fs_info *fs_info)
 {
-       struct btrfs_pending_snapshot *pending;
+       struct btrfs_pending_snapshot *pending, *next;
        struct list_head *head = &trans->transaction->pending_snapshots;
+       int ret = 0;
 
-       list_for_each_entry(pending, head, list)
-               create_pending_snapshot(trans, fs_info, pending);
-       return 0;
+       list_for_each_entry_safe(pending, next, head, list) {
+               list_del(&pending->list);
+               ret = create_pending_snapshot(trans, fs_info, pending);
+               if (ret)
+                       break;
+       }
+       return ret;
 }
 
 static void update_super_roots(struct btrfs_root *root)
@@ -1448,6 +1456,13 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans,
        btrfs_abort_transaction(trans, root, err);
 
        spin_lock(&root->fs_info->trans_lock);
+
+       if (list_empty(&cur_trans->list)) {
+               spin_unlock(&root->fs_info->trans_lock);
+               btrfs_end_transaction(trans, root);
+               return;
+       }
+
        list_del_init(&cur_trans->list);
        if (cur_trans == root->fs_info->running_transaction) {
                root->fs_info->trans_no_join = 1;