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Commit 706dd22f authored by Tycho Andersen's avatar Tycho Andersen Committed by Mike Snitzer
Browse files

dm stripe: get rid of a Variable Length Array (VLA) 

Ideally, we'd like to get rid of all VLAs in the kernel and add -Wvla to
the build args: https://lkml.org/lkml/2018/3/7/621



This one is a simple case, since we don't actually need the VLA at all: we
can just iterate over the stripes twice, once to emit their names, and the
second time to emit status (i.e. trade memory for time). Since the number
of stripes is probably low, this is hopefully not that expensive.

Signed-off-by: default avatarTycho Andersen <tycho@tycho.ws>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent e5c4cb9b

drivers/md/dm-stripe.c

+5 −5
Original line number Diff line number Diff line
@@ -368,7 +368,6 @@ static void stripe_status(struct dm_target *ti, status_type_t type, 
			  unsigned status_flags, char *result, unsigned maxlen)

{

	struct stripe_c *sc = (struct stripe_c *) ti->private;

	char buffer[sc->stripes + 1];

	unsigned int sz = 0;

	unsigned int i;
@@ -377,11 +376,12 @@ static void stripe_status(struct dm_target *ti, status_type_t type, 
		DMEMIT("%d ", sc->stripes);

		for (i = 0; i < sc->stripes; i++)  {

			DMEMIT("%s ", sc->stripe[i].dev->name);

			buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ?

				'D' : 'A';

		}

		buffer[i] = '\0';

		DMEMIT("1 %s", buffer);

		DMEMIT("1 ");

		for (i = 0; i < sc->stripes; i++) {

			DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ?

			       'D' : 'A');

		}

		break;



	case STATUSTYPE_TABLE: