Btrfs: make sure fallocate properly starts a transaction

The recent patch to make fallocate enospc friendly would send
down a NULL trans handle to the allocator.  This moves the
transaction start to properly fix things.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index da76cad92ec..5440bab2363 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5802,23 +5802,23 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
         while (num_bytes > 0) {
                 alloc_size = min(num_bytes, root->fs_info->max_extent);
 
+                trans = btrfs_start_transaction(root, 1);
+
                 ret = btrfs_reserve_extent(trans, root, alloc_size,
                                            root->sectorsize, 0, alloc_hint,
                                            (u64)-1, &ins, 1);
                 if (ret) {
                         WARN_ON(1);
-                        break;
+                        goto stop_trans;
                 }
 
                 ret = btrfs_reserve_metadata_space(root, 3);
                 if (ret) {
                         btrfs_free_reserved_extent(root, ins.objectid,
                                                    ins.offset);
-                        break;
+                        goto stop_trans;
                 }
 
-                trans = btrfs_start_transaction(root, 1);
-
                 ret = insert_reserved_file_extent(trans, inode,
                                                   cur_offset, ins.objectid,
                                                   ins.offset, ins.offset,
@@ -5847,6 +5847,11 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
                 btrfs_unreserve_metadata_space(root, 3);
         }
         return ret;
+
+stop_trans:
+        btrfs_end_transaction(trans, root);
+        return ret;
+
 }
 
 static long btrfs_fallocate(struct inode *inode, int mode,