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MFprojects/camlock r254895:

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Add unmapped BIO support to GEOM ZERO if kern.geom.zero.clear is cleared.
This commit is contained in:
mav 2013-08-26 20:39:02 +00:00
parent 9cfbf27301
commit 3380a03b00
1 changed files with 28 additions and 4 deletions
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32
sys/geom/zero/g_zero.c
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@ -41,16 +41,37 @@ __FBSDID("$FreeBSD$");
#define G_ZERO_CLASS_NAME "ZERO"
static int g_zero_clear_sysctl(SYSCTL_HANDLER_ARGS);
SYSCTL_DECL(_kern_geom);
static SYSCTL_NODE(_kern_geom, OID_AUTO, zero, CTLFLAG_RW, 0,
"GEOM_ZERO stuff");
static int g_zero_clear = 1;
SYSCTL_INT(_kern_geom_zero, OID_AUTO, clear, CTLFLAG_RW, &g_zero_clear, 0,
"Clear read data buffer");
SYSCTL_PROC(_kern_geom_zero, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW,
&g_zero_clear, 0, g_zero_clear_sysctl, "I", "Clear read data buffer");
static int g_zero_byte = 0;
SYSCTL_INT(_kern_geom_zero, OID_AUTO, byte, CTLFLAG_RW, &g_zero_byte, 0,
"Byte (octet) value to clear the buffers with");
static struct g_provider *gpp;
static int
g_zero_clear_sysctl(SYSCTL_HANDLER_ARGS)
{
int error;
error = sysctl_handle_int(oidp, &g_zero_clear, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (gpp == NULL)
return (ENXIO);
if (g_zero_clear)
gpp->flags &= ~G_PF_ACCEPT_UNMAPPED;
else
gpp->flags |= G_PF_ACCEPT_UNMAPPED;
return (0);
}
static void
g_zero_start(struct bio *bp)
{
@ -58,7 +79,7 @@ g_zero_start(struct bio *bp)
switch (bp->bio_cmd) {
case BIO_READ:
if (g_zero_clear)
if (g_zero_clear && (bp->bio_flags & BIO_UNMAPPED) == 0)
memset(bp->bio_data, g_zero_byte, bp->bio_length);
/* FALLTHROUGH */
case BIO_DELETE:
@ -84,7 +105,9 @@ g_zero_init(struct g_class *mp)
gp = g_new_geomf(mp, "gzero");
gp->start = g_zero_start;
gp->access = g_std_access;
pp = g_new_providerf(gp, "%s", gp->name);
gpp = pp = g_new_providerf(gp, "%s", gp->name);
if (!g_zero_clear)
pp->flags |= G_PF_ACCEPT_UNMAPPED;
pp->mediasize = 1152921504606846976LLU;
pp->sectorsize = 512;
g_error_provider(pp, 0);
@ -104,6 +127,7 @@ g_zero_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
return (0);
if (pp->acr > 0 || pp->acw > 0 || pp->ace > 0)
return (EBUSY);
gpp = NULL;
g_wither_geom(gp, ENXIO);
return (0);
}