1 files changed, 23 insertions, 20 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 31168fd45bdc..4d8e3be55976 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1461,34 +1461,37 @@ void file_update_time(struct file *file)
 {
         struct inode *inode = file->f_path.dentry->d_inode;
         struct timespec now;
-        int sync_it = 0;
-        int err;
+        enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
 
+        /* First try to exhaust all avenues to not sync */
         if (IS_NOCMTIME(inode))
                 return;
 
-        err = mnt_want_write_file(file);
-        if (err)
-                return;
-
         now = current_fs_time(inode->i_sb);
-        if (!timespec_equal(&inode->i_mtime, &now)) {
-                inode->i_mtime = now;
-                sync_it = 1;
-        }
+        if (!timespec_equal(&inode->i_mtime, &now))
+                sync_it = S_MTIME;
 
-        if (!timespec_equal(&inode->i_ctime, &now)) {
-                inode->i_ctime = now;
-                sync_it = 1;
-        }
+        if (!timespec_equal(&inode->i_ctime, &now))
+                sync_it |= S_CTIME;
 
-        if (IS_I_VERSION(inode)) {
-                inode_inc_iversion(inode);
-                sync_it = 1;
-        }
+        if (IS_I_VERSION(inode))
+                sync_it |= S_VERSION;
 
-        if (sync_it)
-                mark_inode_dirty_sync(inode);
+        if (!sync_it)
+                return;
+
+        /* Finally allowed to write? Takes lock. */
+        if (mnt_want_write_file(file))
+                return;
+
+        /* Only change inode inside the lock region */
+        if (sync_it & S_VERSION)
+                inode_inc_iversion(inode);
+        if (sync_it & S_CTIME)
+                inode->i_ctime = now;
+        if (sync_it & S_MTIME)
+                inode->i_mtime = now;
+        mark_inode_dirty_sync(inode);
         mnt_drop_write(file->f_path.mnt);
 }
 EXPORT_SYMBOL(file_update_time);