Commit da6ccaaa authored Jan 14, 2016 by Dan Streetman Committed by Markus Pargmann Feb 05, 2016

nbd: ratelimit error msgs after socket close



Make the "Attempted send on closed socket" error messages generated in
nbd_request_handler() ratelimited.

When the nbd socket is shutdown, the nbd_request_handler() function emits
an error message for every request remaining in its queue.  If the queue
is large, this will spam a large amount of messages to the log.  There's
no need for a separate error message for each request, so this patch
ratelimits it.

In the specific case this was found, the system was virtual and the error
messages were logged to the serial port, which overwhelmed it.

Fixes: 4d48a542 ("nbd: fix I/O hang on disconnected nbds")
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>

parent d02cf531

drivers/block/nbd.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -580,7 +580,7 @@ static void nbd_request_handler(struct request_queue *q)
		req, req->cmd_type);

		if (unlikely(!nbd->sock)) {
		dev_err(disk_to_dev(nbd->disk),
		dev_err_ratelimited(disk_to_dev(nbd->disk),
		"Attempted send on closed socket\n");
		req->errors++;
		nbd_end_request(nbd, req);

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