[PATCH] fix posix lock on NFS
NFS client prevents mandatory lock, but there is a flaw on it; Locks are
possibly left if the mode is changed while locking.
This permits unlocking even if the mandatory lock bits are set.
Signed-off-by: ASANO Masahiro <masano@tnes.nec.co.jp>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index eb5cd4c..7a79fbe 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -509,7 +509,8 @@
return -EINVAL;
/* No mandatory locks over NFS */
- if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+ if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
+ fl->fl_type != F_UNLCK)
return -ENOLCK;
if (IS_GETLK(cmd))