3 files changed, 41 insertions, 39 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 02369a3c162e..7d84651e850b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -62,7 +62,7 @@ static void btrfs_destroy_ordered_operations(struct btrfs_transaction *t,
 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
                                       struct btrfs_root *root);
-static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
+static void btrfs_evict_pending_snapshots(struct btrfs_transaction *t);
 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
                                         struct extent_io_tree *dirty_pages,
@@ -3687,7 +3687,7 @@ int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
         return ret;
 }
 
-static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
+static void btrfs_evict_pending_snapshots(struct btrfs_transaction *t)
 {
         struct btrfs_pending_snapshot *snapshot;
         struct list_head splice;
@@ -3700,10 +3700,8 @@ static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
                 snapshot = list_entry(splice.next,
                                       struct btrfs_pending_snapshot,
                                       list);
-
+                snapshot->error = -ECANCELED;
                 list_del_init(&snapshot->list);
-
-                kfree(snapshot);
         }
 }
 
@@ -3840,6 +3838,8 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
         cur_trans->blocked = 1;
         wake_up(&root->fs_info->transaction_blocked_wait);
 
+        btrfs_evict_pending_snapshots(cur_trans);
+
         cur_trans->blocked = 0;
         wake_up(&root->fs_info->transaction_wait);
 
@@ -3849,8 +3849,6 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
         btrfs_destroy_delayed_inodes(root);
         btrfs_assert_delayed_root_empty(root);
 
-        btrfs_destroy_pending_snapshots(cur_trans);
-
         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
                                      EXTENT_DIRTY);
         btrfs_destroy_pinned_extent(root,
@@ -3894,6 +3892,8 @@ int btrfs_cleanup_transaction(struct btrfs_root *root)
                 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
                         wake_up(&root->fs_info->transaction_blocked_wait);
 
+                btrfs_evict_pending_snapshots(t);
+
                 t->blocked = 0;
                 smp_mb();
                 if (waitqueue_active(&root->fs_info->transaction_wait))
@@ -3907,8 +3907,6 @@ int btrfs_cleanup_transaction(struct btrfs_root *root)
                 btrfs_destroy_delayed_inodes(root);
                 btrfs_assert_delayed_root_empty(root);
 
-                btrfs_destroy_pending_snapshots(t);
-
                 btrfs_destroy_delalloc_inodes(root);
 
                 spin_lock(&root->fs_info->trans_lock);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b908960c9746..94c0e42dfa1e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -596,12 +596,8 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
                 ret = btrfs_commit_transaction(trans,
                                                root->fs_info->extent_root);
         }
-        if (ret) {
-                /* cleanup_transaction has freed this for us */
-                if (trans->aborted)
-                        pending_snapshot = NULL;
+        if (ret)
                 goto fail;
-        }
 
         ret = pending_snapshot->error;
         if (ret)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index f11c2e0a3746..d8fce6fe9cf8 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1053,7 +1053,12 @@ 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,
@@ -1072,7 +1077,7 @@ 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;
@@ -1081,40 +1086,36 @@ 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;
@@ -1142,7 +1143,7 @@ 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);
@@ -1273,6 +1274,8 @@ 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:
@@ -1288,12 +1291,17 @@ 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)