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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/amd64/compile/hs32/modules/usr/src/sys/modules/if_faith/@/geom/virstor/g_virstor.c |
/*-
* Copyright (c) 2006-2007 Ivan Voras <ivoras@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Implementation notes:
* - "Components" are wrappers around providers that make up the
* virtual storage (i.e. a virstor has "physical" components)
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/geom/virstor/g_virstor.c 239449 2012-08-20 16:55:55Z jimharris $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/bio.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/mutex.h>
#include <vm/uma.h>
#include <geom/geom.h>
#include <geom/virstor/g_virstor.h>
#include <geom/virstor/g_virstor_md.h>
FEATURE(g_virstor, "GEOM virtual storage support");
/* Declare malloc(9) label */
static MALLOC_DEFINE(M_GVIRSTOR, "gvirstor", "GEOM_VIRSTOR Data");
/* GEOM class methods */
static g_init_t g_virstor_init;
static g_fini_t g_virstor_fini;
static g_taste_t g_virstor_taste;
static g_ctl_req_t g_virstor_config;
static g_ctl_destroy_geom_t g_virstor_destroy_geom;
/* Declare & initialize class structure ("geom class") */
struct g_class g_virstor_class = {
.name = G_VIRSTOR_CLASS_NAME,
.version = G_VERSION,
.init = g_virstor_init,
.fini = g_virstor_fini,
.taste = g_virstor_taste,
.ctlreq = g_virstor_config,
.destroy_geom = g_virstor_destroy_geom
/* The .dumpconf and the rest are only usable for a geom instance, so
* they will be set when such instance is created. */
};
/* Declare sysctl's and loader tunables */
SYSCTL_DECL(_kern_geom);
SYSCTL_NODE(_kern_geom, OID_AUTO, virstor, CTLFLAG_RW, 0, "GEOM_GVIRSTOR information");
static u_int g_virstor_debug = 2; /* XXX: lower to 2 when released to public */
TUNABLE_INT("kern.geom.virstor.debug", &g_virstor_debug);
SYSCTL_UINT(_kern_geom_virstor, OID_AUTO, debug, CTLFLAG_RW, &g_virstor_debug,
0, "Debug level (2=production, 5=normal, 15=excessive)");
static u_int g_virstor_chunk_watermark = 100;
TUNABLE_INT("kern.geom.virstor.chunk_watermark", &g_virstor_chunk_watermark);
SYSCTL_UINT(_kern_geom_virstor, OID_AUTO, chunk_watermark, CTLFLAG_RW,
&g_virstor_chunk_watermark, 0,
"Minimum number of free chunks before issuing administrative warning");
static u_int g_virstor_component_watermark = 1;
TUNABLE_INT("kern.geom.virstor.component_watermark",
&g_virstor_component_watermark);
SYSCTL_UINT(_kern_geom_virstor, OID_AUTO, component_watermark, CTLFLAG_RW,
&g_virstor_component_watermark, 0,
"Minimum number of free components before issuing administrative warning");
static int read_metadata(struct g_consumer *, struct g_virstor_metadata *);
static void write_metadata(struct g_consumer *, struct g_virstor_metadata *);
static int clear_metadata(struct g_virstor_component *);
static int add_provider_to_geom(struct g_virstor_softc *, struct g_provider *,
struct g_virstor_metadata *);
static struct g_geom *create_virstor_geom(struct g_class *,
struct g_virstor_metadata *);
static void virstor_check_and_run(struct g_virstor_softc *);
static u_int virstor_valid_components(struct g_virstor_softc *);
static int virstor_geom_destroy(struct g_virstor_softc *, boolean_t,
boolean_t);
static void remove_component(struct g_virstor_softc *,
struct g_virstor_component *, boolean_t);
static void bioq_dismantle(struct bio_queue_head *);
static int allocate_chunk(struct g_virstor_softc *,
struct g_virstor_component **, u_int *, u_int *);
static void delay_destroy_consumer(void *, int);
static void dump_component(struct g_virstor_component *comp);
#if 0
static void dump_me(struct virstor_map_entry *me, unsigned int nr);
#endif
static void virstor_ctl_stop(struct gctl_req *, struct g_class *);
static void virstor_ctl_add(struct gctl_req *, struct g_class *);
static void virstor_ctl_remove(struct gctl_req *, struct g_class *);
static struct g_virstor_softc * virstor_find_geom(const struct g_class *,
const char *);
static void update_metadata(struct g_virstor_softc *);
static void fill_metadata(struct g_virstor_softc *, struct g_virstor_metadata *,
u_int, u_int);
static void g_virstor_orphan(struct g_consumer *);
static int g_virstor_access(struct g_provider *, int, int, int);
static void g_virstor_start(struct bio *);
static void g_virstor_dumpconf(struct sbuf *, const char *, struct g_geom *,
struct g_consumer *, struct g_provider *);
static void g_virstor_done(struct bio *);
static void invalid_call(void);
/*
* Initialise GEOM class (per-class callback)
*/
static void
g_virstor_init(struct g_class *mp __unused)
{
/* Catch map struct size mismatch at compile time; Map entries must
* fit into MAXPHYS exactly, with no wasted space. */
CTASSERT(VIRSTOR_MAP_BLOCK_ENTRIES*VIRSTOR_MAP_ENTRY_SIZE == MAXPHYS);
/* Init UMA zones, TAILQ's, other global vars */
}
/*
* Finalise GEOM class (per-class callback)
*/
static void
g_virstor_fini(struct g_class *mp __unused)
{
/* Deinit UMA zones & global vars */
}
/*
* Config (per-class callback)
*/
static void
g_virstor_config(struct gctl_req *req, struct g_class *cp, char const *verb)
{
uint32_t *version;
g_topology_assert();
version = gctl_get_paraml(req, "version", sizeof(*version));
if (version == NULL) {
gctl_error(req, "Failed to get 'version' argument");
return;
}
if (*version != G_VIRSTOR_VERSION) {
gctl_error(req, "Userland and kernel versions out of sync");
return;
}
g_topology_unlock();
if (strcmp(verb, "add") == 0)
virstor_ctl_add(req, cp);
else if (strcmp(verb, "stop") == 0 || strcmp(verb, "destroy") == 0)
virstor_ctl_stop(req, cp);
else if (strcmp(verb, "remove") == 0)
virstor_ctl_remove(req, cp);
else
gctl_error(req, "unknown verb: '%s'", verb);
g_topology_lock();
}
/*
* "stop" verb from userland
*/
static void
virstor_ctl_stop(struct gctl_req *req, struct g_class *cp)
{
int *force, *nargs;
int i;
nargs = gctl_get_paraml(req, "nargs", sizeof *nargs);
if (nargs == NULL) {
gctl_error(req, "Error fetching argument '%s'", "nargs");
return;
}
if (*nargs < 1) {
gctl_error(req, "Invalid number of arguments");
return;
}
force = gctl_get_paraml(req, "force", sizeof *force);
if (force == NULL) {
gctl_error(req, "Error fetching argument '%s'", "force");
return;
}
g_topology_lock();
for (i = 0; i < *nargs; i++) {
char param[8];
const char *name;
struct g_virstor_softc *sc;
int error;
sprintf(param, "arg%d", i);
name = gctl_get_asciiparam(req, param);
if (name == NULL) {
gctl_error(req, "No 'arg%d' argument", i);
g_topology_unlock();
return;
}
sc = virstor_find_geom(cp, name);
if (sc == NULL) {
gctl_error(req, "Don't know anything about '%s'", name);
g_topology_unlock();
return;
}
LOG_MSG(LVL_INFO, "Stopping %s by the userland command",
sc->geom->name);
update_metadata(sc);
if ((error = virstor_geom_destroy(sc, TRUE, TRUE)) != 0) {
LOG_MSG(LVL_ERROR, "Cannot destroy %s: %d",
sc->geom->name, error);
}
}
g_topology_unlock();
}
/*
* "add" verb from userland - add new component(s) to the structure.
* This will be done all at once in here, without going through the
* .taste function for new components.
*/
static void
virstor_ctl_add(struct gctl_req *req, struct g_class *cp)
{
/* Note: while this is going on, I/O is being done on
* the g_up and g_down threads. The idea is to make changes
* to softc members in a way that can atomically activate
* them all at once. */
struct g_virstor_softc *sc;
int *hardcode, *nargs;
const char *geom_name; /* geom to add a component to */
struct g_consumer *fcp;
struct g_virstor_bio_q *bq;
u_int added;
int error;
int i;
nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
if (nargs == NULL) {
gctl_error(req, "Error fetching argument '%s'", "nargs");
return;
}
if (*nargs < 2) {
gctl_error(req, "Invalid number of arguments");
return;
}
hardcode = gctl_get_paraml(req, "hardcode", sizeof(*hardcode));
if (hardcode == NULL) {
gctl_error(req, "Error fetching argument '%s'", "hardcode");
return;
}
/* Find "our" geom */
geom_name = gctl_get_asciiparam(req, "arg0");
if (geom_name == NULL) {
gctl_error(req, "Error fetching argument '%s'", "geom_name (arg0)");
return;
}
sc = virstor_find_geom(cp, geom_name);
if (sc == NULL) {
gctl_error(req, "Don't know anything about '%s'", geom_name);
return;
}
if (virstor_valid_components(sc) != sc->n_components) {
LOG_MSG(LVL_ERROR, "Cannot add components to incomplete "
"virstor %s", sc->geom->name);
gctl_error(req, "Virstor %s is incomplete", sc->geom->name);
return;
}
fcp = sc->components[0].gcons;
added = 0;
g_topology_lock();
for (i = 1; i < *nargs; i++) {
struct g_virstor_metadata md;
char aname[8];
const char *prov_name;
struct g_provider *pp;
struct g_consumer *cp;
u_int nc;
u_int j;
snprintf(aname, sizeof aname, "arg%d", i);
prov_name = gctl_get_asciiparam(req, aname);
if (prov_name == NULL) {
gctl_error(req, "Error fetching argument '%s'", aname);
g_topology_unlock();
return;
}
if (strncmp(prov_name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
prov_name += sizeof(_PATH_DEV) - 1;
pp = g_provider_by_name(prov_name);
if (pp == NULL) {
/* This is the most common error so be verbose about it */
if (added != 0) {
gctl_error(req, "Invalid provider: '%s' (added"
" %u components)", prov_name, added);
update_metadata(sc);
} else {
gctl_error(req, "Invalid provider: '%s'",
prov_name);
}
g_topology_unlock();
return;
}
cp = g_new_consumer(sc->geom);
if (cp == NULL) {
gctl_error(req, "Cannot create consumer");
g_topology_unlock();
return;
}
error = g_attach(cp, pp);
if (error != 0) {
gctl_error(req, "Cannot attach a consumer to %s",
pp->name);
g_destroy_consumer(cp);
g_topology_unlock();
return;
}
if (fcp->acr != 0 || fcp->acw != 0 || fcp->ace != 0) {
error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
if (error != 0) {
gctl_error(req, "Access request failed for %s",
pp->name);
g_destroy_consumer(cp);
g_topology_unlock();
return;
}
}
if (fcp->provider->sectorsize != pp->sectorsize) {
gctl_error(req, "Sector size doesn't fit for %s",
pp->name);
g_destroy_consumer(cp);
g_topology_unlock();
return;
}
for (j = 0; j < sc->n_components; j++) {
if (strcmp(sc->components[j].gcons->provider->name,
pp->name) == 0) {
gctl_error(req, "Component %s already in %s",
pp->name, sc->geom->name);
g_destroy_consumer(cp);
g_topology_unlock();
return;
}
}
sc->components = realloc(sc->components,
sizeof(*sc->components) * (sc->n_components + 1),
M_GVIRSTOR, M_WAITOK);
nc = sc->n_components;
sc->components[nc].gcons = cp;
sc->components[nc].sc = sc;
sc->components[nc].index = nc;
sc->components[nc].chunk_count = cp->provider->mediasize /
sc->chunk_size;
sc->components[nc].chunk_next = 0;
sc->components[nc].chunk_reserved = 0;
if (sc->components[nc].chunk_count < 4) {
gctl_error(req, "Provider too small: %s",
cp->provider->name);
g_destroy_consumer(cp);
g_topology_unlock();
return;
}
fill_metadata(sc, &md, nc, *hardcode);
write_metadata(cp, &md);
/* The new component becomes visible when n_components is
* incremented */
sc->n_components++;
added++;
}
/* This call to update_metadata() is critical. In case there's a
* power failure in the middle of it and some components are updated
* while others are not, there will be trouble on next .taste() iff
* a non-updated component is detected first */
update_metadata(sc);
g_topology_unlock();
LOG_MSG(LVL_INFO, "Added %d component(s) to %s", added,
sc->geom->name);
/* Fire off BIOs previously queued because there wasn't any
* physical space left. If the BIOs still can't be satisfied
* they will again be added to the end of the queue (during
* which the mutex will be recursed) */
bq = malloc(sizeof(*bq), M_GVIRSTOR, M_WAITOK);
bq->bio = NULL;
mtx_lock(&sc->delayed_bio_q_mtx);
/* First, insert a sentinel to the queue end, so we don't
* end up in an infinite loop if there's still no free
* space available. */
STAILQ_INSERT_TAIL(&sc->delayed_bio_q, bq, linkage);
while (!STAILQ_EMPTY(&sc->delayed_bio_q)) {
bq = STAILQ_FIRST(&sc->delayed_bio_q);
if (bq->bio != NULL) {
g_virstor_start(bq->bio);
STAILQ_REMOVE_HEAD(&sc->delayed_bio_q, linkage);
free(bq, M_GVIRSTOR);
} else {
STAILQ_REMOVE_HEAD(&sc->delayed_bio_q, linkage);
free(bq, M_GVIRSTOR);
break;
}
}
mtx_unlock(&sc->delayed_bio_q_mtx);
}
/*
* Find a geom handled by the class
*/
static struct g_virstor_softc *
virstor_find_geom(const struct g_class *cp, const char *name)
{
struct g_geom *gp;
LIST_FOREACH(gp, &cp->geom, geom) {
if (strcmp(name, gp->name) == 0)
return (gp->softc);
}
return (NULL);
}
/*
* Update metadata on all components to reflect the current state
* of these fields:
* - chunk_next
* - flags
* - md_count
* Expects things to be set up so write_metadata() can work, i.e.
* the topology lock must be held.
*/
static void
update_metadata(struct g_virstor_softc *sc)
{
struct g_virstor_metadata md;
int n;
if (virstor_valid_components(sc) != sc->n_components)
return; /* Incomplete device */
LOG_MSG(LVL_DEBUG, "Updating metadata on components for %s",
sc->geom->name);
/* Update metadata on components */
g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__,
sc->geom->class->name, sc->geom->name);
g_topology_assert();
for (n = 0; n < sc->n_components; n++) {
read_metadata(sc->components[n].gcons, &md);
md.chunk_next = sc->components[n].chunk_next;
md.flags = sc->components[n].flags;
md.md_count = sc->n_components;
write_metadata(sc->components[n].gcons, &md);
}
}
/*
* Fills metadata (struct md) from information stored in softc and the nc'th
* component of virstor
*/
static void
fill_metadata(struct g_virstor_softc *sc, struct g_virstor_metadata *md,
u_int nc, u_int hardcode)
{
struct g_virstor_component *c;
bzero(md, sizeof *md);
c = &sc->components[nc];
strncpy(md->md_magic, G_VIRSTOR_MAGIC, sizeof md->md_magic);
md->md_version = G_VIRSTOR_VERSION;
strncpy(md->md_name, sc->geom->name, sizeof md->md_name);
md->md_id = sc->id;
md->md_virsize = sc->virsize;
md->md_chunk_size = sc->chunk_size;
md->md_count = sc->n_components;
if (hardcode) {
strncpy(md->provider, c->gcons->provider->name,
sizeof md->provider);
}
md->no = nc;
md->provsize = c->gcons->provider->mediasize;
md->chunk_count = c->chunk_count;
md->chunk_next = c->chunk_next;
md->chunk_reserved = c->chunk_reserved;
md->flags = c->flags;
}
/*
* Remove a component from virstor device.
* Can only be done if the component is unallocated.
*/
static void
virstor_ctl_remove(struct gctl_req *req, struct g_class *cp)
{
/* As this is executed in parallel to I/O, operations on virstor
* structures must be as atomic as possible. */
struct g_virstor_softc *sc;
int *nargs;
const char *geom_name;
u_int removed;
int i;
nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
if (nargs == NULL) {
gctl_error(req, "Error fetching argument '%s'", "nargs");
return;
}
if (*nargs < 2) {
gctl_error(req, "Invalid number of arguments");
return;
}
/* Find "our" geom */
geom_name = gctl_get_asciiparam(req, "arg0");
if (geom_name == NULL) {
gctl_error(req, "Error fetching argument '%s'",
"geom_name (arg0)");
return;
}
sc = virstor_find_geom(cp, geom_name);
if (sc == NULL) {
gctl_error(req, "Don't know anything about '%s'", geom_name);
return;
}
if (virstor_valid_components(sc) != sc->n_components) {
LOG_MSG(LVL_ERROR, "Cannot remove components from incomplete "
"virstor %s", sc->geom->name);
gctl_error(req, "Virstor %s is incomplete", sc->geom->name);
return;
}
removed = 0;
for (i = 1; i < *nargs; i++) {
char param[8];
const char *prov_name;
int j, found;
struct g_virstor_component *newcomp, *compbak;
sprintf(param, "arg%d", i);
prov_name = gctl_get_asciiparam(req, param);
if (prov_name == NULL) {
gctl_error(req, "Error fetching argument '%s'", param);
return;
}
if (strncmp(prov_name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
prov_name += sizeof(_PATH_DEV) - 1;
found = -1;
for (j = 0; j < sc->n_components; j++) {
if (strcmp(sc->components[j].gcons->provider->name,
prov_name) == 0) {
found = j;
break;
}
}
if (found == -1) {
LOG_MSG(LVL_ERROR, "No %s component in %s",
prov_name, sc->geom->name);
continue;
}
compbak = sc->components;
newcomp = malloc(sc->n_components * sizeof(*sc->components),
M_GVIRSTOR, M_WAITOK | M_ZERO);
bcopy(sc->components, newcomp, found * sizeof(*sc->components));
bcopy(&sc->components[found + 1], newcomp + found,
found * sizeof(*sc->components));
if ((sc->components[j].flags & VIRSTOR_PROVIDER_ALLOCATED) != 0) {
LOG_MSG(LVL_ERROR, "Allocated provider %s cannot be "
"removed from %s",
prov_name, sc->geom->name);
free(newcomp, M_GVIRSTOR);
/* We'll consider this non-fatal error */
continue;
}
/* Renumerate unallocated components */
for (j = 0; j < sc->n_components-1; j++) {
if ((sc->components[j].flags &
VIRSTOR_PROVIDER_ALLOCATED) == 0) {
sc->components[j].index = j;
}
}
/* This is the critical section. If a component allocation
* event happens while both variables are not yet set,
* there will be trouble. Something will panic on encountering
* NULL sc->components[x].gcomp member.
* Luckily, component allocation happens very rarely and
* removing components is an abnormal action in any case. */
sc->components = newcomp;
sc->n_components--;
/* End critical section */
g_topology_lock();
if (clear_metadata(&compbak[found]) != 0) {
LOG_MSG(LVL_WARNING, "Trouble ahead: cannot clear "
"metadata on %s", prov_name);
}
g_detach(compbak[found].gcons);
g_destroy_consumer(compbak[found].gcons);
g_topology_unlock();
free(compbak, M_GVIRSTOR);
removed++;
}
/* This call to update_metadata() is critical. In case there's a
* power failure in the middle of it and some components are updated
* while others are not, there will be trouble on next .taste() iff
* a non-updated component is detected first */
g_topology_lock();
update_metadata(sc);
g_topology_unlock();
LOG_MSG(LVL_INFO, "Removed %d component(s) from %s", removed,
sc->geom->name);
}
/*
* Clear metadata sector on component
*/
static int
clear_metadata(struct g_virstor_component *comp)
{
char *buf;
int error;
LOG_MSG(LVL_INFO, "Clearing metadata on %s",
comp->gcons->provider->name);
g_topology_assert();
error = g_access(comp->gcons, 0, 1, 0);
if (error != 0)
return (error);
buf = malloc(comp->gcons->provider->sectorsize, M_GVIRSTOR,
M_WAITOK | M_ZERO);
error = g_write_data(comp->gcons,
comp->gcons->provider->mediasize -
comp->gcons->provider->sectorsize,
buf,
comp->gcons->provider->sectorsize);
free(buf, M_GVIRSTOR);
g_access(comp->gcons, 0, -1, 0);
return (error);
}
/*
* Destroy geom forcibly.
*/
static int
g_virstor_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
struct g_geom *gp)
{
struct g_virstor_softc *sc;
int exitval;
sc = gp->softc;
KASSERT(sc != NULL, ("%s: NULL sc", __func__));
exitval = 0;
LOG_MSG(LVL_DEBUG, "%s called for %s, sc=%p", __func__, gp->name,
gp->softc);
if (sc != NULL) {
#ifdef INVARIANTS
char *buf;
int error;
off_t off;
int isclean, count;
int n;
LOG_MSG(LVL_INFO, "INVARIANTS detected");
LOG_MSG(LVL_INFO, "Verifying allocation "
"table for %s", sc->geom->name);
count = 0;
for (n = 0; n < sc->chunk_count; n++) {
if (sc->map[n].flags || VIRSTOR_MAP_ALLOCATED != 0)
count++;
}
LOG_MSG(LVL_INFO, "Device %s has %d allocated chunks",
sc->geom->name, count);
n = off = count = 0;
isclean = 1;
if (virstor_valid_components(sc) != sc->n_components) {
/* This is a incomplete virstor device (not all
* components have been found) */
LOG_MSG(LVL_ERROR, "Device %s is incomplete",
sc->geom->name);
goto bailout;
}
error = g_access(sc->components[0].gcons, 1, 0, 0);
KASSERT(error == 0, ("%s: g_access failed (%d)", __func__,
error));
/* Compare the whole on-disk allocation table with what's
* currently in memory */
while (n < sc->chunk_count) {
buf = g_read_data(sc->components[0].gcons, off,
sc->sectorsize, &error);
KASSERT(buf != NULL, ("g_read_data returned NULL (%d) "
"for read at %jd", error, off));
if (bcmp(buf, &sc->map[n], sc->sectorsize) != 0) {
LOG_MSG(LVL_ERROR, "ERROR in allocation table, "
"entry %d, offset %jd", n, off);
isclean = 0;
count++;
}
n += sc->me_per_sector;
off += sc->sectorsize;
g_free(buf);
}
error = g_access(sc->components[0].gcons, -1, 0, 0);
KASSERT(error == 0, ("%s: g_access failed (%d) on exit",
__func__, error));
if (isclean != 1) {
LOG_MSG(LVL_ERROR, "ALLOCATION TABLE CORRUPTED FOR %s "
"(%d sectors don't match, max %zu allocations)",
sc->geom->name, count,
count * sc->me_per_sector);
} else {
LOG_MSG(LVL_INFO, "Allocation table ok for %s",
sc->geom->name);
}
bailout:
#endif
update_metadata(sc);
virstor_geom_destroy(sc, FALSE, FALSE);
exitval = EAGAIN;
} else
exitval = 0;
return (exitval);
}
/*
* Taste event (per-class callback)
* Examines a provider and creates geom instances if needed
*/
static struct g_geom *
g_virstor_taste(struct g_class *mp, struct g_provider *pp, int flags)
{
struct g_virstor_metadata md;
struct g_geom *gp;
struct g_consumer *cp;
struct g_virstor_softc *sc;
int error;
g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
g_topology_assert();
LOG_MSG(LVL_DEBUG, "Tasting %s", pp->name);
/* We need a dummy geom to attach a consumer to the given provider */
gp = g_new_geomf(mp, "virstor:taste.helper");
gp->start = (void *)invalid_call; /* XXX: hacked up so the */
gp->access = (void *)invalid_call; /* compiler doesn't complain. */
gp->orphan = (void *)invalid_call; /* I really want these to fail. */
cp = g_new_consumer(gp);
g_attach(cp, pp);
error = read_metadata(cp, &md);
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_geom(gp);
if (error != 0)
return (NULL);
if (strcmp(md.md_magic, G_VIRSTOR_MAGIC) != 0)
return (NULL);
if (md.md_version != G_VIRSTOR_VERSION) {
LOG_MSG(LVL_ERROR, "Kernel module version invalid "
"to handle %s (%s) : %d should be %d",
md.md_name, pp->name, md.md_version, G_VIRSTOR_VERSION);
return (NULL);
}
if (md.provsize != pp->mediasize)
return (NULL);
/* If the provider name is hardcoded, use the offered provider only
* if it's been offered with its proper name (the one used in
* the label command). */
if (md.provider[0] != '\0' &&
!g_compare_names(md.provider, pp->name))
return (NULL);
/* Iterate all geoms this class already knows about to see if a new
* geom instance of this class needs to be created (in case the provider
* is first from a (possibly) multi-consumer geom) or it just needs
* to be added to an existing instance. */
sc = NULL;
gp = NULL;
LIST_FOREACH(gp, &mp->geom, geom) {
sc = gp->softc;
if (sc == NULL)
continue;
if (strcmp(md.md_name, sc->geom->name) != 0)
continue;
if (md.md_id != sc->id)
continue;
break;
}
if (gp != NULL) { /* We found an existing geom instance; add to it */
LOG_MSG(LVL_INFO, "Adding %s to %s", pp->name, md.md_name);
error = add_provider_to_geom(sc, pp, &md);
if (error != 0) {
LOG_MSG(LVL_ERROR, "Error adding %s to %s (error %d)",
pp->name, md.md_name, error);
return (NULL);
}
} else { /* New geom instance needs to be created */
gp = create_virstor_geom(mp, &md);
if (gp == NULL) {
LOG_MSG(LVL_ERROR, "Error creating new instance of "
"class %s: %s", mp->name, md.md_name);
LOG_MSG(LVL_DEBUG, "Error creating %s at %s",
md.md_name, pp->name);
return (NULL);
}
sc = gp->softc;
LOG_MSG(LVL_INFO, "Adding %s to %s (first found)", pp->name,
md.md_name);
error = add_provider_to_geom(sc, pp, &md);
if (error != 0) {
LOG_MSG(LVL_ERROR, "Error adding %s to %s (error %d)",
pp->name, md.md_name, error);
virstor_geom_destroy(sc, TRUE, FALSE);
return (NULL);
}
}
return (gp);
}
/*
* Destroyes consumer passed to it in arguments. Used as a callback
* on g_event queue.
*/
static void
delay_destroy_consumer(void *arg, int flags __unused)
{
struct g_consumer *c = arg;
KASSERT(c != NULL, ("%s: invalid consumer", __func__));
LOG_MSG(LVL_DEBUG, "Consumer %s destroyed with delay",
c->provider->name);
g_detach(c);
g_destroy_consumer(c);
}
/*
* Remove a component (consumer) from geom instance; If it's the first
* component being removed, orphan the provider to announce geom's being
* dismantled
*/
static void
remove_component(struct g_virstor_softc *sc, struct g_virstor_component *comp,
boolean_t delay)
{
struct g_consumer *c;
KASSERT(comp->gcons != NULL, ("Component with no consumer in %s",
sc->geom->name));
c = comp->gcons;
comp->gcons = NULL;
KASSERT(c->provider != NULL, ("%s: no provider", __func__));
LOG_MSG(LVL_DEBUG, "Component %s removed from %s", c->provider->name,
sc->geom->name);
if (sc->provider != NULL) {
/* Whither, GEOM? */
sc->provider->flags |= G_PF_WITHER;
g_orphan_provider(sc->provider, ENXIO);
sc->provider = NULL;
LOG_MSG(LVL_INFO, "Removing provider %s", sc->geom->name);
}
if (c->acr > 0 || c->acw > 0 || c->ace > 0)
g_access(c, -c->acr, -c->acw, -c->ace);
if (delay) {
/* Destroy consumer after it's tasted */
g_post_event(delay_destroy_consumer, c, M_WAITOK, NULL);
} else {
g_detach(c);
g_destroy_consumer(c);
}
}
/*
* Destroy geom - called internally
* See g_virstor_destroy_geom for the other one
*/
static int
virstor_geom_destroy(struct g_virstor_softc *sc, boolean_t force,
boolean_t delay)
{
struct g_provider *pp;
struct g_geom *gp;
int n;
g_topology_assert();
if (sc == NULL)
return (ENXIO);
pp = sc->provider;
if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
LOG_MSG(force ? LVL_WARNING : LVL_ERROR,
"Device %s is still open.", pp->name);
if (!force)
return (EBUSY);
}
for (n = 0; n < sc->n_components; n++) {
if (sc->components[n].gcons != NULL)
remove_component(sc, &sc->components[n], delay);
}
gp = sc->geom;
gp->softc = NULL;
KASSERT(sc->provider == NULL, ("Provider still exists for %s",
gp->name));
/* XXX: This might or might not work, since we're called with
* the topology lock held. Also, it might panic the kernel if
* the error'd BIO is in softupdates code. */
mtx_lock(&sc->delayed_bio_q_mtx);
while (!STAILQ_EMPTY(&sc->delayed_bio_q)) {
struct g_virstor_bio_q *bq;
bq = STAILQ_FIRST(&sc->delayed_bio_q);
bq->bio->bio_error = ENOSPC;
g_io_deliver(bq->bio, EIO);
STAILQ_REMOVE_HEAD(&sc->delayed_bio_q, linkage);
free(bq, M_GVIRSTOR);
}
mtx_unlock(&sc->delayed_bio_q_mtx);
mtx_destroy(&sc->delayed_bio_q_mtx);
free(sc->map, M_GVIRSTOR);
free(sc->components, M_GVIRSTOR);
bzero(sc, sizeof *sc);
free(sc, M_GVIRSTOR);
pp = LIST_FIRST(&gp->provider); /* We only offer one provider */
if (pp == NULL || (pp->acr == 0 && pp->acw == 0 && pp->ace == 0))
LOG_MSG(LVL_DEBUG, "Device %s destroyed", gp->name);
g_wither_geom(gp, ENXIO);
return (0);
}
/*
* Utility function: read metadata & decode. Wants topology lock to be
* held.
*/
static int
read_metadata(struct g_consumer *cp, struct g_virstor_metadata *md)
{
struct g_provider *pp;
char *buf;
int error;
g_topology_assert();
error = g_access(cp, 1, 0, 0);
if (error != 0)
return (error);
pp = cp->provider;
g_topology_unlock();
buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
&error);
g_topology_lock();
g_access(cp, -1, 0, 0);
if (buf == NULL)
return (error);
virstor_metadata_decode(buf, md);
g_free(buf);
return (0);
}
/**
* Utility function: encode & write metadata. Assumes topology lock is
* held.
*
* There is no useful way of recovering from errors in this function,
* not involving panicking the kernel. If the metadata cannot be written
* the most we can do is notify the operator and hope he spots it and
* replaces the broken drive.
*/
static void
write_metadata(struct g_consumer *cp, struct g_virstor_metadata *md)
{
struct g_provider *pp;
char *buf;
int error;
KASSERT(cp != NULL && md != NULL && cp->provider != NULL,
("Something's fishy in %s", __func__));
LOG_MSG(LVL_DEBUG, "Writing metadata on %s", cp->provider->name);
g_topology_assert();
error = g_access(cp, 0, 1, 0);
if (error != 0) {
LOG_MSG(LVL_ERROR, "g_access(0,1,0) failed for %s: %d",
cp->provider->name, error);
return;
}
pp = cp->provider;
buf = malloc(pp->sectorsize, M_GVIRSTOR, M_WAITOK);
virstor_metadata_encode(md, buf);
g_topology_unlock();
error = g_write_data(cp, pp->mediasize - pp->sectorsize, buf,
pp->sectorsize);
g_topology_lock();
g_access(cp, 0, -1, 0);
free(buf, M_GVIRSTOR);
if (error != 0)
LOG_MSG(LVL_ERROR, "Error %d writing metadata to %s",
error, cp->provider->name);
}
/*
* Creates a new instance of this GEOM class, initialise softc
*/
static struct g_geom *
create_virstor_geom(struct g_class *mp, struct g_virstor_metadata *md)
{
struct g_geom *gp;
struct g_virstor_softc *sc;
LOG_MSG(LVL_DEBUG, "Creating geom instance for %s (id=%u)",
md->md_name, md->md_id);
if (md->md_count < 1 || md->md_chunk_size < 1 ||
md->md_virsize < md->md_chunk_size) {
/* This is bogus configuration, and probably means data is
* somehow corrupted. Panic, maybe? */
LOG_MSG(LVL_ERROR, "Nonsensical metadata information for %s",
md->md_name);
return (NULL);
}
/* Check if it's already created */
LIST_FOREACH(gp, &mp->geom, geom) {
sc = gp->softc;
if (sc != NULL && strcmp(sc->geom->name, md->md_name) == 0) {
LOG_MSG(LVL_WARNING, "Geom %s already exists",
md->md_name);
if (sc->id != md->md_id) {
LOG_MSG(LVL_ERROR,
"Some stale or invalid components "
"exist for virstor device named %s. "
"You will need to <CLEAR> all stale "
"components and maybe reconfigure "
"the virstor device. Tune "
"kern.geom.virstor.debug sysctl up "
"for more information.",
sc->geom->name);
}
return (NULL);
}
}
gp = g_new_geomf(mp, "%s", md->md_name);
gp->softc = NULL; /* to circumevent races that test softc */
gp->start = g_virstor_start;
gp->spoiled = g_virstor_orphan;
gp->orphan = g_virstor_orphan;
gp->access = g_virstor_access;
gp->dumpconf = g_virstor_dumpconf;
sc = malloc(sizeof(*sc), M_GVIRSTOR, M_WAITOK | M_ZERO);
sc->id = md->md_id;
sc->n_components = md->md_count;
sc->components = malloc(sizeof(struct g_virstor_component) * md->md_count,
M_GVIRSTOR, M_WAITOK | M_ZERO);
sc->chunk_size = md->md_chunk_size;
sc->virsize = md->md_virsize;
STAILQ_INIT(&sc->delayed_bio_q);
mtx_init(&sc->delayed_bio_q_mtx, "gvirstor_delayed_bio_q_mtx",
"gvirstor", MTX_DEF | MTX_RECURSE);
sc->geom = gp;
sc->provider = NULL; /* virstor_check_and_run will create it */
gp->softc = sc;
LOG_MSG(LVL_ANNOUNCE, "Device %s created", sc->geom->name);
return (gp);
}
/*
* Add provider to a GEOM class instance
*/
static int
add_provider_to_geom(struct g_virstor_softc *sc, struct g_provider *pp,
struct g_virstor_metadata *md)
{
struct g_virstor_component *component;
struct g_consumer *cp, *fcp;
struct g_geom *gp;
int error;
if (md->no >= sc->n_components)
return (EINVAL);
/* "Current" compontent */
component = &(sc->components[md->no]);
if (component->gcons != NULL)
return (EEXIST);
gp = sc->geom;
fcp = LIST_FIRST(&gp->consumer);
cp = g_new_consumer(gp);
error = g_attach(cp, pp);
if (error != 0) {
g_destroy_consumer(cp);
return (error);
}
if (fcp != NULL) {
if (fcp->provider->sectorsize != pp->sectorsize) {
/* TODO: this can be made to work */
LOG_MSG(LVL_ERROR, "Provider %s of %s has invalid "
"sector size (%d)", pp->name, sc->geom->name,
pp->sectorsize);
return (EINVAL);
}
if (fcp->acr > 0 || fcp->acw || fcp->ace > 0) {
/* Replicate access permissions from first "live" consumer
* to the new one */
error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
if (error != 0) {
g_detach(cp);
g_destroy_consumer(cp);
return (error);
}
}
}
/* Bring up a new component */
cp->private = component;
component->gcons = cp;
component->sc = sc;
component->index = md->no;
component->chunk_count = md->chunk_count;
component->chunk_next = md->chunk_next;
component->chunk_reserved = md->chunk_reserved;
component->flags = md->flags;
LOG_MSG(LVL_DEBUG, "%s attached to %s", pp->name, sc->geom->name);
virstor_check_and_run(sc);
return (0);
}
/*
* Check if everything's ready to create the geom provider & device entry,
* create and start provider.
* Called ultimately by .taste, from g_event thread
*/
static void
virstor_check_and_run(struct g_virstor_softc *sc)
{
off_t off;
size_t n, count;
int index;
int error;
if (virstor_valid_components(sc) != sc->n_components)
return;
if (virstor_valid_components(sc) == 0) {
/* This is actually a candidate for panic() */
LOG_MSG(LVL_ERROR, "No valid components for %s?",
sc->provider->name);
return;
}
sc->sectorsize = sc->components[0].gcons->provider->sectorsize;
/* Initialise allocation map from the first consumer */
sc->chunk_count = sc->virsize / sc->chunk_size;
if (sc->chunk_count * (off_t)sc->chunk_size != sc->virsize) {
LOG_MSG(LVL_WARNING, "Device %s truncated to %ju bytes",
sc->provider->name,
sc->chunk_count * (off_t)sc->chunk_size);
}
sc->map_size = sc->chunk_count * sizeof *(sc->map);
/* The following allocation is in order of 4MB - 8MB */
sc->map = malloc(sc->map_size, M_GVIRSTOR, M_WAITOK);
KASSERT(sc->map != NULL, ("%s: Memory allocation error (%zu bytes) for %s",
__func__, sc->map_size, sc->provider->name));
sc->map_sectors = sc->map_size / sc->sectorsize;
count = 0;
for (n = 0; n < sc->n_components; n++)
count += sc->components[n].chunk_count;
LOG_MSG(LVL_INFO, "Device %s has %zu physical chunks and %zu virtual "
"(%zu KB chunks)",
sc->geom->name, count, sc->chunk_count, sc->chunk_size / 1024);
error = g_access(sc->components[0].gcons, 1, 0, 0);
if (error != 0) {
LOG_MSG(LVL_ERROR, "Cannot acquire read access for %s to "
"read allocation map for %s",
sc->components[0].gcons->provider->name,
sc->geom->name);
return;
}
/* Read in the allocation map */
LOG_MSG(LVL_DEBUG, "Reading map for %s from %s", sc->geom->name,
sc->components[0].gcons->provider->name);
off = count = n = 0;
while (count < sc->map_size) {
struct g_virstor_map_entry *mapbuf;
size_t bs;
bs = MIN(MAXPHYS, sc->map_size - count);
if (bs % sc->sectorsize != 0) {
/* Check for alignment errors */
bs = (bs / sc->sectorsize) * sc->sectorsize;
if (bs == 0)
break;
LOG_MSG(LVL_ERROR, "Trouble: map is not sector-aligned "
"for %s on %s", sc->geom->name,
sc->components[0].gcons->provider->name);
}
mapbuf = g_read_data(sc->components[0].gcons, off, bs, &error);
if (mapbuf == NULL) {
free(sc->map, M_GVIRSTOR);
LOG_MSG(LVL_ERROR, "Error reading allocation map "
"for %s from %s (offset %ju) (error %d)",
sc->geom->name,
sc->components[0].gcons->provider->name,
off, error);
return;
}
bcopy(mapbuf, &sc->map[n], bs);
off += bs;
count += bs;
n += bs / sizeof *(sc->map);
g_free(mapbuf);
}
g_access(sc->components[0].gcons, -1, 0, 0);
LOG_MSG(LVL_DEBUG, "Read map for %s", sc->geom->name);
/* find first component with allocatable chunks */
index = -1;
for (n = 0; n < sc->n_components; n++) {
if (sc->components[n].chunk_next <
sc->components[n].chunk_count) {
index = n;
break;
}
}
if (index == -1)
/* not found? set it to the last component and handle it
* later */
index = sc->n_components - 1;
if (index >= sc->n_components - g_virstor_component_watermark - 1) {
LOG_MSG(LVL_WARNING, "Device %s running out of components "
"(%d/%u: %s)", sc->geom->name,
index+1,
sc->n_components,
sc->components[index].gcons->provider->name);
}
sc->curr_component = index;
if (sc->components[index].chunk_next >=
sc->components[index].chunk_count - g_virstor_chunk_watermark) {
LOG_MSG(LVL_WARNING,
"Component %s of %s is running out of free space "
"(%u chunks left)",
sc->components[index].gcons->provider->name,
sc->geom->name, sc->components[index].chunk_count -
sc->components[index].chunk_next);
}
sc->me_per_sector = sc->sectorsize / sizeof *(sc->map);
if (sc->sectorsize % sizeof *(sc->map) != 0) {
LOG_MSG(LVL_ERROR,
"%s: Map entries don't fit exactly in a sector (%s)",
__func__, sc->geom->name);
return;
}
/* Recalculate allocated chunks in components & at the same time
* verify map data is sane. We could trust metadata on this, but
* we want to make sure. */
for (n = 0; n < sc->n_components; n++)
sc->components[n].chunk_next = sc->components[n].chunk_reserved;
for (n = 0; n < sc->chunk_count; n++) {
if (sc->map[n].provider_no >= sc->n_components ||
sc->map[n].provider_chunk >=
sc->components[sc->map[n].provider_no].chunk_count) {
LOG_MSG(LVL_ERROR, "%s: Invalid entry %u in map for %s",
__func__, (u_int)n, sc->geom->name);
LOG_MSG(LVL_ERROR, "%s: provider_no: %u, n_components: %u"
" provider_chunk: %u, chunk_count: %u", __func__,
sc->map[n].provider_no, sc->n_components,
sc->map[n].provider_chunk,
sc->components[sc->map[n].provider_no].chunk_count);
return;
}
if (sc->map[n].flags & VIRSTOR_MAP_ALLOCATED)
sc->components[sc->map[n].provider_no].chunk_next++;
}
sc->provider = g_new_providerf(sc->geom, "virstor/%s",
sc->geom->name);
sc->provider->sectorsize = sc->sectorsize;
sc->provider->mediasize = sc->virsize;
g_error_provider(sc->provider, 0);
LOG_MSG(LVL_INFO, "%s activated", sc->provider->name);
LOG_MSG(LVL_DEBUG, "%s starting with current component %u, starting "
"chunk %u", sc->provider->name, sc->curr_component,
sc->components[sc->curr_component].chunk_next);
}
/*
* Returns count of active providers in this geom instance
*/
static u_int
virstor_valid_components(struct g_virstor_softc *sc)
{
unsigned int nc, i;
nc = 0;
KASSERT(sc != NULL, ("%s: softc is NULL", __func__));
KASSERT(sc->components != NULL, ("%s: sc->components is NULL", __func__));
for (i = 0; i < sc->n_components; i++)
if (sc->components[i].gcons != NULL)
nc++;
return (nc);
}
/*
* Called when the consumer gets orphaned (?)
*/
static void
g_virstor_orphan(struct g_consumer *cp)
{
struct g_virstor_softc *sc;
struct g_virstor_component *comp;
struct g_geom *gp;
g_topology_assert();
gp = cp->geom;
sc = gp->softc;
if (sc == NULL)
return;
comp = cp->private;
KASSERT(comp != NULL, ("%s: No component in private part of consumer",
__func__));
remove_component(sc, comp, FALSE);
if (virstor_valid_components(sc) == 0)
virstor_geom_destroy(sc, TRUE, FALSE);
}
/*
* Called to notify geom when it's been opened, and for what intent
*/
static int
g_virstor_access(struct g_provider *pp, int dr, int dw, int de)
{
struct g_consumer *c;
struct g_virstor_softc *sc;
struct g_geom *gp;
int error;
KASSERT(pp != NULL, ("%s: NULL provider", __func__));
gp = pp->geom;
KASSERT(gp != NULL, ("%s: NULL geom", __func__));
sc = gp->softc;
if (sc == NULL) {
/* It seems that .access can be called with negative dr,dw,dx
* in this case but I want to check for myself */
LOG_MSG(LVL_WARNING, "access(%d, %d, %d) for %s",
dr, dw, de, pp->name);
/* This should only happen when geom is withered so
* allow only negative requests */
KASSERT(dr <= 0 && dw <= 0 && de <= 0,
("%s: Positive access for %s", __func__, pp->name));
if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
LOG_MSG(LVL_DEBUG, "Device %s definitely destroyed",
pp->name);
return (0);
}
/* Grab an exclusive bit to propagate on our consumers on first open */
if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
de++;
/* ... drop it on close */
if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0) {
de--;
update_metadata(sc); /* Writes statistical information */
}
error = ENXIO;
LIST_FOREACH(c, &gp->consumer, consumer) {
KASSERT(c != NULL, ("%s: consumer is NULL", __func__));
error = g_access(c, dr, dw, de);
if (error != 0) {
struct g_consumer *c2;
/* Backout earlier changes */
LIST_FOREACH(c2, &gp->consumer, consumer) {
if (c2 == c) /* all eariler components fixed */
return (error);
g_access(c2, -dr, -dw, -de);
}
}
}
return (error);
}
/*
* Generate XML dump of current state
*/
static void
g_virstor_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
struct g_consumer *cp, struct g_provider *pp)
{
struct g_virstor_softc *sc;
g_topology_assert();
sc = gp->softc;
if (sc == NULL || pp != NULL)
return;
if (cp != NULL) {
/* For each component */
struct g_virstor_component *comp;
comp = cp->private;
if (comp == NULL)
return;
sbuf_printf(sb, "%s<ComponentIndex>%u</ComponentIndex>\n",
indent, comp->index);
sbuf_printf(sb, "%s<ChunkCount>%u</ChunkCount>\n",
indent, comp->chunk_count);
sbuf_printf(sb, "%s<ChunksUsed>%u</ChunksUsed>\n",
indent, comp->chunk_next);
sbuf_printf(sb, "%s<ChunksReserved>%u</ChunksReserved>\n",
indent, comp->chunk_reserved);
sbuf_printf(sb, "%s<StorageFree>%u%%</StorageFree>\n",
indent,
comp->chunk_next > 0 ? 100 -
((comp->chunk_next + comp->chunk_reserved) * 100) /
comp->chunk_count : 100);
} else {
/* For the whole thing */
u_int count, used, i;
off_t size;
count = used = size = 0;
for (i = 0; i < sc->n_components; i++) {
if (sc->components[i].gcons != NULL) {
count += sc->components[i].chunk_count;
used += sc->components[i].chunk_next +
sc->components[i].chunk_reserved;
size += sc->components[i].gcons->
provider->mediasize;
}
}
sbuf_printf(sb, "%s<Status>"
"Components=%u, Online=%u</Status>\n", indent,
sc->n_components, virstor_valid_components(sc));
sbuf_printf(sb, "%s<State>%u%% physical free</State>\n",
indent, 100-(used * 100) / count);
sbuf_printf(sb, "%s<ChunkSize>%zu</ChunkSize>\n", indent,
sc->chunk_size);
sbuf_printf(sb, "%s<PhysicalFree>%u%%</PhysicalFree>\n",
indent, used > 0 ? 100 - (used * 100) / count : 100);
sbuf_printf(sb, "%s<ChunkPhysicalCount>%u</ChunkPhysicalCount>\n",
indent, count);
sbuf_printf(sb, "%s<ChunkVirtualCount>%zu</ChunkVirtualCount>\n",
indent, sc->chunk_count);
sbuf_printf(sb, "%s<PhysicalBacking>%zu%%</PhysicalBacking>\n",
indent,
(count * 100) / sc->chunk_count);
sbuf_printf(sb, "%s<PhysicalBackingSize>%jd</PhysicalBackingSize>\n",
indent, size);
sbuf_printf(sb, "%s<VirtualSize>%jd</VirtualSize>\n", indent,
sc->virsize);
}
}
/*
* GEOM .done handler
* Can't use standard handler because one requested IO may
* fork into additional data IOs
*/
static void
g_virstor_done(struct bio *b)
{
struct g_virstor_softc *sc;
struct bio *parent_b;
parent_b = b->bio_parent;
sc = parent_b->bio_to->geom->softc;
if (b->bio_error != 0) {
LOG_MSG(LVL_ERROR, "Error %d for offset=%ju, length=%ju, %s",
b->bio_error, b->bio_offset, b->bio_length,
b->bio_to->name);
if (parent_b->bio_error == 0)
parent_b->bio_error = b->bio_error;
}
parent_b->bio_inbed++;
parent_b->bio_completed += b->bio_completed;
if (parent_b->bio_children == parent_b->bio_inbed) {
parent_b->bio_completed = parent_b->bio_length;
g_io_deliver(parent_b, parent_b->bio_error);
}
g_destroy_bio(b);
}
/*
* I/O starts here
* Called in g_down thread
*/
static void
g_virstor_start(struct bio *b)
{
struct g_virstor_softc *sc;
struct g_virstor_component *comp;
struct bio *cb;
struct g_provider *pp;
char *addr;
off_t offset, length;
struct bio_queue_head bq;
size_t chunk_size; /* cached for convenience */
u_int count;
pp = b->bio_to;
sc = pp->geom->softc;
KASSERT(sc != NULL, ("%s: no softc (error=%d, device=%s)", __func__,
b->bio_to->error, b->bio_to->name));
LOG_REQ(LVL_MOREDEBUG, b, "%s", __func__);
switch (b->bio_cmd) {
case BIO_READ:
case BIO_WRITE:
case BIO_DELETE:
break;
default:
g_io_deliver(b, EOPNOTSUPP);
return;
}
LOG_MSG(LVL_DEBUG2, "BIO arrived, size=%ju", b->bio_length);
bioq_init(&bq);
chunk_size = sc->chunk_size;
addr = b->bio_data;
offset = b->bio_offset; /* virtual offset and length */
length = b->bio_length;
while (length > 0) {
size_t chunk_index, in_chunk_offset, in_chunk_length;
struct virstor_map_entry *me;
chunk_index = offset / chunk_size; /* round downwards */
in_chunk_offset = offset % chunk_size;
in_chunk_length = min(length, chunk_size - in_chunk_offset);
LOG_MSG(LVL_DEBUG, "Mapped %s(%ju, %ju) to (%zu,%zu,%zu)",
b->bio_cmd == BIO_READ ? "R" : "W",
offset, length,
chunk_index, in_chunk_offset, in_chunk_length);
me = &sc->map[chunk_index];
if (b->bio_cmd == BIO_READ || b->bio_cmd == BIO_DELETE) {
if ((me->flags & VIRSTOR_MAP_ALLOCATED) == 0) {
/* Reads from unallocated chunks return zeroed
* buffers */
if (b->bio_cmd == BIO_READ)
bzero(addr, in_chunk_length);
} else {
comp = &sc->components[me->provider_no];
cb = g_clone_bio(b);
if (cb == NULL) {
bioq_dismantle(&bq);
if (b->bio_error == 0)
b->bio_error = ENOMEM;
g_io_deliver(b, b->bio_error);
return;
}
cb->bio_to = comp->gcons->provider;
cb->bio_done = g_virstor_done;
cb->bio_offset =
(off_t)me->provider_chunk * (off_t)chunk_size
+ in_chunk_offset;
cb->bio_length = in_chunk_length;
cb->bio_data = addr;
cb->bio_caller1 = comp;
bioq_disksort(&bq, cb);
}
} else { /* handle BIO_WRITE */
KASSERT(b->bio_cmd == BIO_WRITE,
("%s: Unknown command %d", __func__,
b->bio_cmd));
if ((me->flags & VIRSTOR_MAP_ALLOCATED) == 0) {
/* We have a virtual chunk, represented by
* the "me" entry, but it's not yet allocated
* (tied to) a physical chunk. So do it now. */
struct virstor_map_entry *data_me;
u_int phys_chunk, comp_no;
off_t s_offset;
int error;
error = allocate_chunk(sc, &comp, &comp_no,
&phys_chunk);
if (error != 0) {
/* We cannot allocate a physical chunk
* to satisfy this request, so we'll
* delay it to when we can...
* XXX: this will prevent the fs from
* being umounted! */
struct g_virstor_bio_q *biq;
biq = malloc(sizeof *biq, M_GVIRSTOR,
M_NOWAIT);
if (biq == NULL) {
bioq_dismantle(&bq);
if (b->bio_error == 0)
b->bio_error = ENOMEM;
g_io_deliver(b, b->bio_error);
return;
}
biq->bio = b;
mtx_lock(&sc->delayed_bio_q_mtx);
STAILQ_INSERT_TAIL(&sc->delayed_bio_q,
biq, linkage);
mtx_unlock(&sc->delayed_bio_q_mtx);
LOG_MSG(LVL_WARNING, "Delaying BIO "
"(size=%ju) until free physical "
"space can be found on %s",
b->bio_length,
sc->provider->name);
return;
}
LOG_MSG(LVL_DEBUG, "Allocated chunk %u on %s "
"for %s",
phys_chunk,
comp->gcons->provider->name,
sc->provider->name);
me->provider_no = comp_no;
me->provider_chunk = phys_chunk;
me->flags |= VIRSTOR_MAP_ALLOCATED;
cb = g_clone_bio(b);
if (cb == NULL) {
me->flags &= ~VIRSTOR_MAP_ALLOCATED;
me->provider_no = 0;
me->provider_chunk = 0;
bioq_dismantle(&bq);
if (b->bio_error == 0)
b->bio_error = ENOMEM;
g_io_deliver(b, b->bio_error);
return;
}
/* The allocation table is stored continuously
* at the start of the drive. We need to
* calculate the offset of the sector that holds
* this map entry both on the drive and in the
* map array.
* sc_offset will end up pointing to the drive
* sector. */
s_offset = chunk_index * sizeof *me;
s_offset = (s_offset / sc->sectorsize) *
sc->sectorsize;
/* data_me points to map entry sector
* in memory (analoguos to offset) */
data_me = &sc->map[(chunk_index /
sc->me_per_sector) * sc->me_per_sector];
/* Commit sector with map entry to storage */
cb->bio_to = sc->components[0].gcons->provider;
cb->bio_done = g_virstor_done;
cb->bio_offset = s_offset;
cb->bio_data = (char *)data_me;
cb->bio_length = sc->sectorsize;
cb->bio_caller1 = &sc->components[0];
bioq_disksort(&bq, cb);
}
comp = &sc->components[me->provider_no];
cb = g_clone_bio(b);
if (cb == NULL) {
bioq_dismantle(&bq);
if (b->bio_error == 0)
b->bio_error = ENOMEM;
g_io_deliver(b, b->bio_error);
return;
}
/* Finally, handle the data */
cb->bio_to = comp->gcons->provider;
cb->bio_done = g_virstor_done;
cb->bio_offset = (off_t)me->provider_chunk*(off_t)chunk_size +
in_chunk_offset;
cb->bio_length = in_chunk_length;
cb->bio_data = addr;
cb->bio_caller1 = comp;
bioq_disksort(&bq, cb);
}
addr += in_chunk_length;
length -= in_chunk_length;
offset += in_chunk_length;
}
/* Fire off bio's here */
count = 0;
for (cb = bioq_first(&bq); cb != NULL; cb = bioq_first(&bq)) {
bioq_remove(&bq, cb);
LOG_REQ(LVL_MOREDEBUG, cb, "Firing request");
comp = cb->bio_caller1;
cb->bio_caller1 = NULL;
LOG_MSG(LVL_DEBUG, " firing bio, offset=%ju, length=%ju",
cb->bio_offset, cb->bio_length);
g_io_request(cb, comp->gcons);
count++;
}
if (count == 0) { /* We handled everything locally */
b->bio_completed = b->bio_length;
g_io_deliver(b, 0);
}
}
/*
* Allocate a chunk from a physical provider. Returns physical component,
* chunk index relative to the component and the component's index.
*/
static int
allocate_chunk(struct g_virstor_softc *sc, struct g_virstor_component **comp,
u_int *comp_no_p, u_int *chunk)
{
u_int comp_no;
KASSERT(sc->curr_component < sc->n_components,
("%s: Invalid curr_component: %u", __func__, sc->curr_component));
comp_no = sc->curr_component;
*comp = &sc->components[comp_no];
dump_component(*comp);
if ((*comp)->chunk_next >= (*comp)->chunk_count) {
/* This component is full. Allocate next component */
if (comp_no >= sc->n_components-1) {
LOG_MSG(LVL_ERROR, "All physical space allocated for %s",
sc->geom->name);
return (-1);
}
(*comp)->flags &= ~VIRSTOR_PROVIDER_CURRENT;
sc->curr_component = ++comp_no;
*comp = &sc->components[comp_no];
if (comp_no >= sc->n_components - g_virstor_component_watermark-1)
LOG_MSG(LVL_WARNING, "Device %s running out of components "
"(switching to %u/%u: %s)", sc->geom->name,
comp_no+1, sc->n_components,
(*comp)->gcons->provider->name);
/* Take care not to overwrite reserved chunks */
if ( (*comp)->chunk_reserved > 0 &&
(*comp)->chunk_next < (*comp)->chunk_reserved)
(*comp)->chunk_next = (*comp)->chunk_reserved;
(*comp)->flags |=
VIRSTOR_PROVIDER_ALLOCATED | VIRSTOR_PROVIDER_CURRENT;
dump_component(*comp);
*comp_no_p = comp_no;
*chunk = (*comp)->chunk_next++;
} else {
*comp_no_p = comp_no;
*chunk = (*comp)->chunk_next++;
}
return (0);
}
/* Dump a component */
static void
dump_component(struct g_virstor_component *comp)
{
if (g_virstor_debug < LVL_DEBUG2)
return;
printf("Component %d: %s\n", comp->index, comp->gcons->provider->name);
printf(" chunk_count: %u\n", comp->chunk_count);
printf(" chunk_next: %u\n", comp->chunk_next);
printf(" flags: %u\n", comp->flags);
}
#if 0
/* Dump a map entry */
static void
dump_me(struct virstor_map_entry *me, unsigned int nr)
{
if (g_virstor_debug < LVL_DEBUG)
return;
printf("VIRT. CHUNK #%d: ", nr);
if ((me->flags & VIRSTOR_MAP_ALLOCATED) == 0)
printf("(unallocated)\n");
else
printf("allocated at provider %u, provider_chunk %u\n",
me->provider_no, me->provider_chunk);
}
#endif
/*
* Dismantle bio_queue and destroy its components
*/
static void
bioq_dismantle(struct bio_queue_head *bq)
{
struct bio *b;
for (b = bioq_first(bq); b != NULL; b = bioq_first(bq)) {
bioq_remove(bq, b);
g_destroy_bio(b);
}
}
/*
* The function that shouldn't be called.
* When this is called, the stack is already garbled because of
* argument mismatch. There's nothing to do now but panic, which is
* accidentally the whole purpose of this function.
* Motivation: to guard from accidentally calling geom methods when
* they shouldn't be called. (see g_..._taste)
*/
static void
invalid_call(void)
{
panic("invalid_call() has just been called. Something's fishy here.");
}
DECLARE_GEOM_CLASS(g_virstor_class, g_virstor); /* Let there be light */