f2fs: fix writing incorrect orphan blocks

Previously, there was a erroneous scenario like below.
thread 1:                       thread 2:
 f2fs_unlink
  - acquire_orphan_inode
    : sbi->n_orphans++           write_checkpoint
                                 - block_operations
                                  : f2fs_lock_all
                                 - do_checkpoint
                                  : write orphan blocks with sbi->n_orphans
                                 - unblock_operations
  - f2fs_lock_op
  - release_orphan_inode
  - f2fs_unlock_op

During the checkpoint by thread 2, f2fs stores a wrong orphan block according
to the wrong sbi->n_orphans.
To avoid this, simply we should make cover acquire_orphan_inode too with
f2fs_lock_op.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 29f73fdf958e..575adac17f8b 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -228,14 +228,14 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
         if (!de)
                 goto fail;
 
+        f2fs_lock_op(sbi);
         err = acquire_orphan_inode(sbi);
         if (err) {
+                f2fs_unlock_op(sbi);
                 kunmap(page);
                 f2fs_put_page(page, 0);
                 goto fail;
         }
-
-        f2fs_lock_op(sbi);
         f2fs_delete_entry(de, page, inode);
         f2fs_unlock_op(sbi);