locks: break delegations on any attribute modification

NFSv4 uses leases to guarantee that clients can cache metadata as well
as data.

Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/utimes.c b/fs/utimes.c
index f4fb7eca10e8..aa138d64560a 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -53,6 +53,7 @@ static int utimes_common(struct path *path, struct timespec *times)
         int error;
         struct iattr newattrs;
         struct inode *inode = path->dentry->d_inode;
+        struct inode *delegated_inode = NULL;
 
         error = mnt_want_write(path->mnt);
         if (error)
@@ -101,9 +102,15 @@ static int utimes_common(struct path *path, struct timespec *times)
                                 goto mnt_drop_write_and_out;
                 }
         }
+retry_deleg:
         mutex_lock(&inode->i_mutex);
-        error = notify_change(path->dentry, &newattrs);
+        error = notify_change(path->dentry, &newattrs, &delegated_inode);
         mutex_unlock(&inode->i_mutex);
+        if (delegated_inode) {
+                error = break_deleg_wait(&delegated_inode);
+                if (!error)
+                        goto retry_deleg;
+        }
 
 mnt_drop_write_and_out:
         mnt_drop_write(path->mnt);