tree e00f99b506f1c1a16e3ba987e3390deda6bd2e03
parent f8cc774ce4844811a55e2352f1443055e3994e28
author Miklos Szeredi <miklos@szeredi.hu> 1239731321 +0200
committer Jens Axboe <jens.axboe@oracle.com> 1239790212 +0200

splice: add helpers for locking pipe inode

There are lots of sequences like this, especially in splice code:

	if (pipe->inode)
		mutex_lock(&pipe->inode->i_mutex);
	/* do something */
	if (pipe->inode)
		mutex_unlock(&pipe->inode->i_mutex);

so introduce helpers which do the conditional locking and unlocking.
Also replace the inode_double_lock() call with a pipe_double_lock()
helper to avoid spreading the use of this functionality beyond the
pipe code.

This patch is just a cleanup, and should cause no behavioral changes.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>