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Commit 0982368b authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Jens Axboe
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drbd: fix for truncated minor number in callback command line 



The command line parameter the kernel module uses to communicate the
device minor to userland helper is flawed in a way that the device
indentifier "minor-%d" is being truncated to minors with a maximum
of 5 digits.

But DRBD 8.4 allows 2^20 == 1048576 minors,
thus a minimum of 7 digits must be supported.

Reported by Veit Wahlich on drbd-dev.

Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 1b228c98

drivers/block/drbd/drbd_nl.c

+2 −2
Original line number Diff line number Diff line
@@ -343,7 +343,7 @@ int drbd_khelper(struct drbd_device *device, char *cmd) 
			 (char[20]) { }, /* address family */

			 (char[60]) { }, /* address */

			NULL };

	char mb[12];

	char mb[14];

	char *argv[] = {usermode_helper, cmd, mb, NULL };

	struct drbd_connection *connection = first_peer_device(device)->connection;

	struct sib_info sib;
@@ -352,7 +352,7 @@ int drbd_khelper(struct drbd_device *device, char *cmd) 
	if (current == connection->worker.task)

		set_bit(CALLBACK_PENDING, &connection->flags);



	snprintf(mb, 12, "minor-%d", device_to_minor(device));

	snprintf(mb, 14, "minor-%d", device_to_minor(device));

	setup_khelper_env(connection, envp);



	/* The helper may take some time.