locks,lockd: fix race in nlmsvc_testlock

[safe/jmp/linux-2.6] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index cb940b1..231b23c 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -672,8 +672,9 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w
        return result;
 }
 
-struct file_lock *
-posix_test_lock(struct file *filp, struct file_lock *fl)
+int
+posix_test_lock(struct file *filp, struct file_lock *fl,
+               struct file_lock *conflock)
 {
        struct file_lock *cfl;
 
@@ -684,9 +685,13 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
                if (posix_locks_conflict(cfl, fl))
                        break;
        }
+       if (cfl) {
+               locks_copy_lock(conflock, cfl);
+               unlock_kernel();
+               return 1;
+       }
        unlock_kernel();
-
-       return (cfl);
+       return 0;
 }
 
 EXPORT_SYMBOL(posix_test_lock);
@@ -1563,7 +1568,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
  */
 int fcntl_getlk(struct file *filp, struct flock __user *l)
 {
-       struct file_lock *fl, file_lock;
+       struct file_lock *fl, cfl, file_lock;
        struct flock flock;
        int error;
 
@@ -1587,7 +1592,7 @@ int fcntl_getlk(struct file *filp, struct flock __user *l)
                else
                  fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
        } else {
-               fl = posix_test_lock(filp, &file_lock);
+               fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
        }
  
        flock.l_type = F_UNLCK;
@@ -1717,7 +1722,7 @@ out:
  */
 int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
 {
-       struct file_lock *fl, file_lock;
+       struct file_lock *fl, cfl, file_lock;
        struct flock64 flock;
        int error;
 
@@ -1741,7 +1746,7 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
                else
                  fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
        } else {
-               fl = posix_test_lock(filp, &file_lock);
+               fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
        }
  
        flock.l_type = F_UNLCK;