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, 5 insertions, 1 deletions

diff --git a/fs/inode.c b/fs/inode.c
index ce48c359ce9e..4bcdad3c9361 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1603,7 +1603,11 @@ static int __remove_suid(struct dentry *dentry, int kill)
         struct iattr newattrs;
 
         newattrs.ia_valid = ATTR_FORCE | kill;
-        return notify_change(dentry, &newattrs);
+        /*
+         * Note we call this on write, so notify_change will not
+         * encounter any conflicting delegations:
+         */
+        return notify_change(dentry, &newattrs, NULL);
 }
 
 int file_remove_suid(struct file *file)