Commit 764c76b3 authored Jul 25, 2008 by Miklos Szeredi Committed by Linus Torvalds Jul 25, 2008

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 <mszeredi@suse.cz>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b648a6de

fs/locks.c

+9 −14

Original line number	Original line	Diff line number	Diff line
	@@ -1747,22 +1747,17 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd,
	if (error)		if (error)
	return error;		return error;

	if (filp->f_op && filp->f_op->lock != NULL)
	error = filp->f_op->lock(filp, cmd, fl);
	else {
	for (;;) {		for (;;) {
	error = posix_lock_file(filp, fl, NULL);		error = vfs_lock_file(filp, cmd, fl, NULL);
	if (error != FILE_LOCK_DEFERRED)		if (error != FILE_LOCK_DEFERRED)
	break;		break;
	error = wait_event_interruptible(fl->fl_wait,		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
	!fl->fl_next);
	if (!error)		if (!error)
	continue;		continue;

	locks_delete_block(fl);		locks_delete_block(fl);
	break;		break;
	}		}
	}

	return error;		return error;
	}		}