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Implement a gctl handler and the verb "write MBR" which can be used to

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update metadata and bootcode while the MBR is in use.

MFC candidate
This commit is contained in:
Poul-Henning Kamp 2005-07-15 08:00:44 +00:00
parent a976a7a3c0
commit 1c3cf26412
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=148034
1 changed files with 55 additions and 5 deletions
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60
sys/geom/geom_mbr.c
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@ -86,8 +86,12 @@ struct g_mbr_softc {
u_char slicesum[16];
};
/*
* XXX: Add gctl_req arg and give good error msgs.
* XXX: Check that length argument does not bring boot code inside any slice.
*/
static int
g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0)
g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0, int len __unused)
{
int i, error;
off_t l[NDOSPART];
@ -104,8 +108,6 @@ g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0)
dos_partition_dec(
sec0 + DOSPARTOFF + i * sizeof(struct dos_partition),
dp + i);
if (0 && bootverbose)
g_mbr_print(i, dp + i);
}
if ((!bcmp(dp, historical_bogus_partition_table,
sizeof historical_bogus_partition_table)) ||
@ -193,7 +195,7 @@ g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thr
opened = 1;
}
if (!error)
error = g_mbr_modify(gp, ms, data);
error = g_mbr_modify(gp, ms, data, 512);
if (!error)
error = g_write_data(cp, 0, data, 512);
if (opened)
@ -301,7 +303,7 @@ g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
}
g_topology_lock();
g_mbr_modify(gp, ms, buf);
g_mbr_modify(gp, ms, buf, 512);
g_topology_unlock();
g_free(buf);
break;
@ -315,11 +317,59 @@ g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
return (gp);
}
static void
g_mbr_config(struct gctl_req *req, struct g_class *mp, const char *verb)
{
struct g_geom *gp;
struct g_consumer *cp;
struct g_mbr_softc *ms;
struct g_slicer *gsp;
int opened = 0, error = 0;
void *data;
int len;
g_topology_assert();
gp = gctl_get_geom(req, mp, "geom");
if (gp == NULL)
return;
if (strcmp(verb, "write MBR")) {
gctl_error(req, "Unknown verb");
return;
}
gsp = gp->softc;
ms = gsp->softc;
data = gctl_get_param(req, "data", &len);
if (data == NULL)
return;
if (len < 512 || (len % 512)) {
gctl_error(req, "Wrong request length");
return;
}
cp = LIST_FIRST(&gp->consumer);
if (cp->acw == 0) {
error = g_access(cp, 0, 1, 0);
if (error == 0)
opened = 1;
}
if (!error)
error = g_mbr_modify(gp, ms, data, len);
if (error)
gctl_error(req, "conflict with open slices");
if (!error)
error = g_write_data(cp, 0, data, len);
if (error)
gctl_error(req, "sector zero write failed");
if (opened)
g_access(cp, 0, -1 , 0);
return;
}
static struct g_class g_mbr_class = {
.name = MBR_CLASS_NAME,
.version = G_VERSION,
.taste = g_mbr_taste,
.dumpconf = g_mbr_dumpconf,
.ctlreq = g_mbr_config,
.ioctl = g_mbr_ioctl,
};