ext4: remove i_mutex from ext4_file_sync()

After removal of ext4_flush_unwritten_io() call, ext4_file_sync()
doesn't need i_mutex anymore. Forcing of transaction commits doesn't
need i_mutex as there's nothing inode specific in that code apart from
grabbing transaction ids from the inode. So remove the lock.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 6 deletions

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 6019bd449576..fc938ebbddec 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -99,20 +99,18 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
         trace_ext4_sync_file_enter(file, datasync);
 
         if (inode->i_sb->s_flags & MS_RDONLY)
-                goto out_trace;
+                goto out;
 
         if (!journal) {
                 ret = generic_file_fsync(file, start, end, datasync);
                 if (!ret && !hlist_empty(&inode->i_dentry))
                         ret = ext4_sync_parent(inode);
-                goto out_trace;
+                goto out;
         }
 
         ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
         if (ret)
                 return ret;
-        mutex_lock(&inode->i_mutex);
-
         /*
          * data=writeback,ordered:
          *  The caller's filemap_fdatawrite()/wait will sync the data.
@@ -143,8 +141,6 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
                         ret = err;
         }
 out:
-        mutex_unlock(&inode->i_mutex);
-out_trace:
         trace_ext4_sync_file_exit(inode, ret);
         return ret;
 }