Btrfs: Integrate metadata reservation with start_transaction

Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.

Changes since V1:

Add code that check if unlink and rmdir will free space.

Add ENOSPC handling for clone ioctl.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 574594cf6b51..054b4475c757 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1522,7 +1522,7 @@ static int transaction_kthread(void *arg)
                         goto sleep;
                 }
                 mutex_unlock(&root->fs_info->trans_mutex);
-                trans = btrfs_start_transaction(root, 1);
+                trans = btrfs_join_transaction(root, 1);
                 ret = btrfs_commit_transaction(trans, root);
 
 sleep:
@@ -2409,11 +2409,11 @@ int btrfs_commit_super(struct btrfs_root *root)
         down_write(&root->fs_info->cleanup_work_sem);
         up_write(&root->fs_info->cleanup_work_sem);
 
-        trans = btrfs_start_transaction(root, 1);
+        trans = btrfs_join_transaction(root, 1);
         ret = btrfs_commit_transaction(trans, root);
         BUG_ON(ret);
         /* run commit again to drop the original snapshot */
-        trans = btrfs_start_transaction(root, 1);
+        trans = btrfs_join_transaction(root, 1);
         btrfs_commit_transaction(trans, root);
         ret = btrfs_write_and_wait_transaction(NULL, root);
         BUG_ON(ret);