[src/trunk]: src/sys/dev Fix error handling in cgdstrategy().

[mlelstv <mlelstv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f4e8d453df58
branches:  trunk
changeset: 817890:f4e8d453df58
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Wed Sep 14 23:16:30 2016 +0000

description:
Fix error handling in cgdstrategy().

- check cgd_softc != NULL, may happen in rare memory shortage situations.
- no longer test geometry, the same check is done in dk_strategy which
  knows to check for an uninitialized geometry.

diffstat:

 sys/dev/cgd.c |  38 ++++++++++++++++++++------------------
 1 files changed, 20 insertions(+), 18 deletions(-)

diffs (67 lines):

diff -r f1cb1d413669 -r f4e8d453df58 sys/dev/cgd.c
--- a/sys/dev/cgd.c     Wed Sep 14 23:05:05 2016 +0000
+++ b/sys/dev/cgd.c     Wed Sep 14 23:16:30 2016 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: cgd.c,v 1.110 2016/08/05 08:24:46 pgoyette Exp $ */
+/* $NetBSD: cgd.c,v 1.111 2016/09/14 23:16:30 mlelstv Exp $ */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.110 2016/08/05 08:24:46 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.111 2016/09/14 23:16:30 mlelstv Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -305,30 +305,32 @@
 static void
 cgdstrategy(struct buf *bp)
 {
-       struct  cgd_softc *cs = getcgd_softc(bp->b_dev);
-       struct  dk_softc *dksc = &cs->sc_dksc;
-       struct  disk_geom *dg = &dksc->sc_dkdev.dk_geom;
+       struct  cgd_softc *cs;
 
        DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
            (long)bp->b_bcount));
 
-       /*
-        * Reject unaligned writes.  We can encrypt and decrypt only
-        * complete disk sectors, and we let the ciphers require their
-        * buffers to be aligned to 32-bit boundaries.
-        */
-       if (bp->b_blkno < 0 ||
-           (bp->b_bcount % dg->dg_secsize) != 0 ||
-           ((uintptr_t)bp->b_data & 3) != 0) {
-               bp->b_error = EINVAL;
-               bp->b_resid = bp->b_bcount;
-               biodone(bp);
-               return;
+       cs = getcgd_softc(bp->b_dev);
+       if (!cs) {
+               bp->b_error = ENXIO;
+               goto bail;
        }
 
-       /* XXXrcd: Should we test for (cs != NULL)? */
+       /*
+        * Reject unaligned writes.
+        */
+       if (((uintptr_t)bp->b_data & 3) != 0) {
+               bp->b_error = EINVAL;
+               goto bail;
+       }
+
        dk_strategy(&cs->sc_dksc, bp);
        return;
+
+bail:
+       bp->b_resid = bp->b_bcount;
+       biodone(bp);
+       return;
 }
 
 static int