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>
This commit is contained in:
Miklos Szeredi 2008-07-25 01:48:58 -07:00 committed by Linus Torvalds
parent b648a6de00
commit 764c76b371

View file

@ -1747,22 +1747,17 @@ 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);
error = vfs_lock_file(filp, cmd, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
error = wait_event_interruptible(fl->fl_wait,
!fl->fl_next);
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
if (!error)
continue;
locks_delete_block(fl);
break;
}
}
return error;
}