Commit 2a6751e0 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

nbd: Improve the documentation of the locking assumptions 



Document locking assumptions with lockdep_assert_held() instead of source
code comments. The advantage of lockdep_assert_held() is that it is
verified at runtime if lockdep is enabled in the kernel config.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240510202313.25209-4-bvanassche@acm.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 40639e9a

drivers/block/nbd.c

+5 −1
Original line number Diff line number Diff line
@@ -588,7 +588,6 @@ static inline int was_interrupted(int result) 
	return result == -ERESTARTSYS || result == -EINTR;

}



/* always call with the tx_lock held */

static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)

{

	struct request *req = blk_mq_rq_from_pdu(cmd);
@@ -605,6 +604,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	u32 nbd_cmd_flags = 0;

	int sent = nsock->sent, skip = 0;



	lockdep_assert_held(&cmd->lock);

	lockdep_assert_held(&nsock->tx_lock);



	iov_iter_kvec(&from, ITER_SOURCE, &iov, 1, sizeof(request));



	type = req_to_nbd_cmd_type(req);
@@ -1015,6 +1017,8 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index) 
	struct nbd_sock *nsock;

	int ret;



	lockdep_assert_held(&cmd->lock);



	config = nbd_get_config_unlocked(nbd);

	if (!config) {

		dev_err_ratelimited(disk_to_dev(nbd->disk),