locks: allow ->lock() to return FILE_LOCK_DEFERRED

Allow filesystem's ->lock() method to call posix_lock_file() instead of
posix_lock_file_wait(), and return FILE_LOCK_DEFERRED.  This makes it
possible to implement a such a ->lock() function, that works with the lock
manager, which needs the call to be asynchronous.

Now the vfs_lock_file() helper can be used, so this is a cleanup as well.

Signed-off-by: Miklos Szeredi <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: David Teigland <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Miklos Szeredi 2008-07-25 01:48:58 -07:00 • committed by Linus Torvalds
commit 764c76b371

View file

@ -1747,21 +1747,16 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd,
if (error)
return error;
if (filp->f_op && filp->f_op->lock != NULL)
error = filp->f_op->lock(filp, cmd, fl);
else {
for (;;) {
error = posix_lock_file(filp, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
error = wait_event_interruptible(fl->fl_wait,
!fl->fl_next);
if (!error)
continue;
locks_delete_block(fl);
for (;;) {
error = vfs_lock_file(filp, cmd, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
}
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
if (!error)
continue;
locks_delete_block(fl);
break;
}
return error;