gnop(8): Nopify configuration as a kernel dump device

As a dummy / no-op dump device, to facilitate dumpon(8) testing.

Reviewed by:	markj (earlier version)
Differential Revision:	https://reviews.freebsd.org/D19991
This commit is contained in:
Conrad Meyer 2019-04-22 03:25:49 +00:00
parent 5a9170aa4c
commit 83efd2885e
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=346516

View File

@ -97,6 +97,42 @@ g_nop_resize(struct g_consumer *cp)
g_resize_provider(pp, size);
}
static int
g_nop_dumper(void *priv, void *virtual, vm_offset_t physical, off_t offset,
size_t length)
{
return (0);
}
static void
g_nop_kerneldump(struct bio *bp, struct g_nop_softc *sc)
{
struct g_kerneldump *gkd;
struct g_geom *gp;
struct g_provider *pp;
gkd = (struct g_kerneldump *)bp->bio_data;
gp = bp->bio_to->geom;
g_trace(G_T_TOPOLOGY, "%s(%s, %jd, %jd)", __func__, gp->name,
(intmax_t)gkd->offset, (intmax_t)gkd->length);
pp = LIST_FIRST(&gp->provider);
gkd->di.dumper = g_nop_dumper;
gkd->di.priv = sc;
gkd->di.blocksize = pp->sectorsize;
gkd->di.maxiosize = DFLTPHYS;
gkd->di.mediaoffset = sc->sc_offset + gkd->offset;
if (gkd->offset > sc->sc_explicitsize) {
g_io_deliver(bp, ENODEV);
return;
}
if (gkd->offset + gkd->length > sc->sc_explicitsize)
gkd->length = sc->sc_explicitsize - gkd->offset;
gkd->di.mediasize = gkd->length;
g_io_deliver(bp, 0);
}
static void
g_nop_start(struct bio *bp)
{
@ -127,11 +163,18 @@ g_nop_start(struct bio *bp)
case BIO_GETATTR:
sc->sc_getattrs++;
if (sc->sc_physpath &&
g_handleattr_str(bp, "GEOM::physpath", sc->sc_physpath)) {
mtx_unlock(&sc->sc_lock);
return;
}
break;
g_handleattr_str(bp, "GEOM::physpath", sc->sc_physpath))
;
else if (strcmp(bp->bio_attribute, "GEOM::kerneldump") == 0)
g_nop_kerneldump(bp, sc);
else
/*
* Fallthrough to forwarding the GETATTR down to the
* lower level device.
*/
break;
mtx_unlock(&sc->sc_lock);
return;
case BIO_FLUSH:
sc->sc_flushes++;
break;