[src/trunk]: src/sys/dev/dkwedge dkwedge_add: Allow for expanding the size of...

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

details:   https://anonhg.NetBSD.org/src/rev/0405dc7eacf8
branches:  trunk
changeset: 972341:0405dc7eacf8
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sun May 24 14:40:21 2020 +0000

description:
dkwedge_add: Allow for expanding the size of an existing wedge without
having to delete it first, provided that no other parameters have changed.

diffstat:

 sys/dev/dkwedge/dk.c |  33 +++++++++++++++++++++++++++++++--
 1 files changed, 31 insertions(+), 2 deletions(-)

diffs (61 lines):

diff -r 2c1a63d297bb -r 0405dc7eacf8 sys/dev/dkwedge/dk.c
--- a/sys/dev/dkwedge/dk.c      Sun May 24 14:11:49 2020 +0000
+++ b/sys/dev/dkwedge/dk.c      Sun May 24 14:40:21 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: dk.c,v 1.100 2020/03/02 16:01:56 riastradh Exp $       */
+/*     $NetBSD: dk.c,v 1.101 2020/05/24 14:40:21 jmcneill Exp $        */
 
 /*-
  * Copyright (c) 2004, 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.100 2020/03/02 16:01:56 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.101 2020/05/24 14:40:21 jmcneill Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_dkwedge.h"
@@ -310,6 +310,34 @@
        if (dkw->dkw_offset < 0)
                return (EINVAL);
 
+       /*
+        * Check for an existing wedge at the same disk offset. Allow
+        * updating a wedge if the only change is the size, and the new
+        * size is larger than the old.
+        */
+       sc = NULL;
+       mutex_enter(&pdk->dk_openlock);
+       LIST_FOREACH(lsc, &pdk->dk_wedges, sc_plink) {
+               if (lsc->sc_offset != dkw->dkw_offset)
+                       continue;
+               if (strcmp(lsc->sc_wname, dkw->dkw_wname) != 0)
+                       break;
+               if (strcmp(lsc->sc_ptype, dkw->dkw_ptype) != 0)
+                       break;
+               if (lsc->sc_size > dkw->dkw_size)
+                       break;
+
+               sc = lsc;
+               sc->sc_size = dkw->dkw_size;
+               dk_set_geometry(sc, pdk);
+
+               break;
+       }
+       mutex_exit(&pdk->dk_openlock);
+
+       if (sc != NULL)
+               goto announce;
+
        sc = malloc(sizeof(*sc), M_DKWEDGE, M_WAITOK|M_ZERO);
        sc->sc_state = DKW_STATE_LARVAL;
        sc->sc_parent = pdk;
@@ -475,6 +503,7 @@
        /* Disk wedge is ready for use! */
        sc->sc_state = DKW_STATE_RUNNING;
 
+announce:
        /* Announce our arrival. */
        aprint_normal(
            "%s at %s: \"%s\", %"PRIu64" blocks at %"PRId64", type: %s\n",