Commit 30c7c1c6 authored by Evgeniy Polyakov's avatar Evgeniy Polyakov Committed by Greg Kroah-Hartman
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Staging: DST: Do not allow empty barriers. 



Do not allow empty barriers or generic_make_request() ->  scsi_setup_fs_cmnd()
will explode

Signed-off-by: default avatarEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e55b6892

drivers/staging/dst/dcore.c

+23 −0
Original line number Diff line number Diff line
@@ -100,10 +100,33 @@ static void dst_node_set_size(struct dst_node *n) 
static int dst_request(struct request_queue *q, struct bio *bio)

{

	struct dst_node *n = q->queuedata;

	int err = -EIO;



	if (bio_empty_barrier(bio) && !q->prepare_discard_fn) {

		/*

		 * This is a dirty^Wnice hack, but if we complete this

		 * operation with -EOPNOTSUPP like intended, XFS

		 * will stuck and freeze the machine. This may be

		 * not particulary XFS problem though, but it is the

		 * only FS which sends empty barrier at umount time

		 * I worked with.

		 *

		 * Empty barriers are not allowed anyway, see 51fd77bd9f512

		 * for example, although later it was changed to bio_discard()

		 * only, which does not work in this case.

		 */

		//err = -EOPNOTSUPP;

		err = 0;

		goto end_io;

	}



	bio_get(bio);



	return dst_process_bio(n, bio);



end_io:

	bio_endio(bio, err);

	return err;

}



/*