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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/geom/vinum/geom_vinum_raid5.c |
/*-
* Copyright (c) 2004, 2007 Lukas Ertl
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/geom/vinum/geom_vinum_raid5.c 191856 2009-05-06 19:34:32Z lulf $");
#include <sys/param.h>
#include <sys/bio.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <geom/geom.h>
#include <geom/vinum/geom_vinum_var.h>
#include <geom/vinum/geom_vinum_raid5.h>
#include <geom/vinum/geom_vinum.h>
static int gv_raid5_offset(struct gv_plex *, off_t, off_t,
off_t *, off_t *, int *, int *, int);
static struct bio * gv_raid5_clone_bio(struct bio *, struct gv_sd *,
struct gv_raid5_packet *, caddr_t, int);
static int gv_raid5_request(struct gv_plex *, struct gv_raid5_packet *,
struct bio *, caddr_t, off_t, off_t, int *);
static int gv_raid5_check(struct gv_plex *, struct gv_raid5_packet *,
struct bio *, caddr_t, off_t, off_t);
static int gv_raid5_rebuild(struct gv_plex *, struct gv_raid5_packet *,
struct bio *, caddr_t, off_t, off_t);
struct gv_raid5_packet *
gv_raid5_start(struct gv_plex *p, struct bio *bp, caddr_t addr, off_t boff,
off_t bcount)
{
struct bio *cbp;
struct gv_raid5_packet *wp, *wp2;
struct gv_bioq *bq, *bq2;
int err, delay;
delay = 0;
wp = g_malloc(sizeof(*wp), M_WAITOK | M_ZERO);
wp->bio = bp;
wp->waiting = NULL;
wp->parity = NULL;
TAILQ_INIT(&wp->bits);
if (bp->bio_pflags & GV_BIO_REBUILD)
err = gv_raid5_rebuild(p, wp, bp, addr, boff, bcount);
else if (bp->bio_pflags & GV_BIO_CHECK)
err = gv_raid5_check(p, wp, bp, addr, boff, bcount);
else
err = gv_raid5_request(p, wp, bp, addr, boff, bcount, &delay);
/* Means we have a delayed request. */
if (delay) {
g_free(wp);
return (NULL);
}
/*
* Building the sub-request failed, we probably need to clean up a lot.
*/
if (err) {
G_VINUM_LOGREQ(0, bp, "raid5 plex request failed.");
TAILQ_FOREACH_SAFE(bq, &wp->bits, queue, bq2) {
TAILQ_REMOVE(&wp->bits, bq, queue);
g_free(bq);
}
if (wp->waiting != NULL) {
if (wp->waiting->bio_cflags & GV_BIO_MALLOC)
g_free(wp->waiting->bio_data);
g_destroy_bio(wp->waiting);
}
if (wp->parity != NULL) {
if (wp->parity->bio_cflags & GV_BIO_MALLOC)
g_free(wp->parity->bio_data);
g_destroy_bio(wp->parity);
}
g_free(wp);
TAILQ_FOREACH_SAFE(wp, &p->packets, list, wp2) {
if (wp->bio != bp)
continue;
TAILQ_REMOVE(&p->packets, wp, list);
TAILQ_FOREACH_SAFE(bq, &wp->bits, queue, bq2) {
TAILQ_REMOVE(&wp->bits, bq, queue);
g_free(bq);
}
g_free(wp);
}
cbp = bioq_takefirst(p->bqueue);
while (cbp != NULL) {
if (cbp->bio_cflags & GV_BIO_MALLOC)
g_free(cbp->bio_data);
g_destroy_bio(cbp);
cbp = bioq_takefirst(p->bqueue);
}
/* If internal, stop and reset state. */
if (bp->bio_pflags & GV_BIO_INTERNAL) {
if (bp->bio_pflags & GV_BIO_MALLOC)
g_free(bp->bio_data);
g_destroy_bio(bp);
/* Reset flags. */
p->flags &= ~(GV_PLEX_SYNCING | GV_PLEX_REBUILDING |
GV_PLEX_GROWING);
return (NULL);
}
g_io_deliver(bp, err);
return (NULL);
}
return (wp);
}
/*
* Check if the stripe that the work packet wants is already being used by
* some other work packet.
*/
int
gv_stripe_active(struct gv_plex *p, struct bio *bp)
{
struct gv_raid5_packet *wp, *owp;
int overlap;
wp = bp->bio_caller2;
if (wp->lockbase == -1)
return (0);
overlap = 0;
TAILQ_FOREACH(owp, &p->packets, list) {
if (owp == wp)
break;
if ((wp->lockbase >= owp->lockbase) &&
(wp->lockbase <= owp->lockbase + owp->length)) {
overlap++;
break;
}
if ((wp->lockbase <= owp->lockbase) &&
(wp->lockbase + wp->length >= owp->lockbase)) {
overlap++;
break;
}
}
return (overlap);
}
static int
gv_raid5_check(struct gv_plex *p, struct gv_raid5_packet *wp, struct bio *bp,
caddr_t addr, off_t boff, off_t bcount)
{
struct gv_sd *parity, *s;
struct gv_bioq *bq;
struct bio *cbp;
int i, psdno;
off_t real_len, real_off;
if (p == NULL || LIST_EMPTY(&p->subdisks))
return (ENXIO);
gv_raid5_offset(p, boff, bcount, &real_off, &real_len, NULL, &psdno, 1);
/* Find the right subdisk. */
parity = NULL;
i = 0;
LIST_FOREACH(s, &p->subdisks, in_plex) {
if (i == psdno) {
parity = s;
break;
}
i++;
}
/* Parity stripe not found. */
if (parity == NULL)
return (ENXIO);
if (parity->state != GV_SD_UP)
return (ENXIO);
wp->length = real_len;
wp->data = addr;
wp->lockbase = real_off;
/* Read all subdisks. */
LIST_FOREACH(s, &p->subdisks, in_plex) {
/* Skip the parity subdisk. */
if (s == parity)
continue;
/* Skip growing subdisks. */
if (s->flags & GV_SD_GROW)
continue;
cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
}
/* Read the parity data. */
cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
wp->waiting = cbp;
/*
* In case we want to rebuild the parity, create an extra BIO to write
* it out. It also acts as buffer for the XOR operations.
*/
cbp = gv_raid5_clone_bio(bp, parity, wp, addr, 1);
if (cbp == NULL)
return (ENOMEM);
wp->parity = cbp;
return (0);
}
/* Rebuild a degraded RAID5 plex. */
static int
gv_raid5_rebuild(struct gv_plex *p, struct gv_raid5_packet *wp, struct bio *bp,
caddr_t addr, off_t boff, off_t bcount)
{
struct gv_sd *broken, *s;
struct gv_bioq *bq;
struct bio *cbp;
off_t real_len, real_off;
if (p == NULL || LIST_EMPTY(&p->subdisks))
return (ENXIO);
gv_raid5_offset(p, boff, bcount, &real_off, &real_len, NULL, NULL, 1);
/* Find the right subdisk. */
broken = NULL;
LIST_FOREACH(s, &p->subdisks, in_plex) {
if (s->state != GV_SD_UP)
broken = s;
}
/* Broken stripe not found. */
if (broken == NULL)
return (ENXIO);
switch (broken->state) {
case GV_SD_UP:
return (EINVAL);
case GV_SD_STALE:
if (!(bp->bio_pflags & GV_BIO_REBUILD))
return (ENXIO);
G_VINUM_DEBUG(1, "sd %s is reviving", broken->name);
gv_set_sd_state(broken, GV_SD_REVIVING, GV_SETSTATE_FORCE);
/* Set this bit now, but should be set at end. */
broken->flags |= GV_SD_CANGOUP;
break;
case GV_SD_REVIVING:
break;
default:
/* All other subdisk states mean it's not accessible. */
return (ENXIO);
}
wp->length = real_len;
wp->data = addr;
wp->lockbase = real_off;
KASSERT(wp->length >= 0, ("gv_rebuild_raid5: wp->length < 0"));
/* Read all subdisks. */
LIST_FOREACH(s, &p->subdisks, in_plex) {
/* Skip the broken subdisk. */
if (s == broken)
continue;
/* Skip growing subdisks. */
if (s->flags & GV_SD_GROW)
continue;
cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
}
/* Write the parity data. */
cbp = gv_raid5_clone_bio(bp, broken, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
wp->parity = cbp;
p->synced = boff;
/* Post notification that we're finished. */
return (0);
}
/* Build a request group to perform (part of) a RAID5 request. */
static int
gv_raid5_request(struct gv_plex *p, struct gv_raid5_packet *wp,
struct bio *bp, caddr_t addr, off_t boff, off_t bcount, int *delay)
{
struct g_geom *gp;
struct gv_sd *broken, *original, *parity, *s;
struct gv_bioq *bq;
struct bio *cbp;
int i, psdno, sdno, type, grow;
off_t real_len, real_off;
gp = bp->bio_to->geom;
if (p == NULL || LIST_EMPTY(&p->subdisks))
return (ENXIO);
/* We are optimistic and assume that this request will be OK. */
#define REQ_TYPE_NORMAL 0
#define REQ_TYPE_DEGRADED 1
#define REQ_TYPE_NOPARITY 2
type = REQ_TYPE_NORMAL;
original = parity = broken = NULL;
/* XXX: The resize won't crash with rebuild or sync, but we should still
* be aware of it. Also this should perhaps be done on rebuild/check as
* well?
*/
/* If we're over, we must use the old. */
if (boff >= p->synced) {
grow = 1;
/* Or if over the resized offset, we use all drives. */
} else if (boff + bcount <= p->synced) {
grow = 0;
/* Else, we're in the middle, and must wait a bit. */
} else {
bioq_disksort(p->rqueue, bp);
*delay = 1;
return (0);
}
gv_raid5_offset(p, boff, bcount, &real_off, &real_len,
&sdno, &psdno, grow);
/* Find the right subdisks. */
i = 0;
LIST_FOREACH(s, &p->subdisks, in_plex) {
if (i == sdno)
original = s;
if (i == psdno)
parity = s;
if (s->state != GV_SD_UP)
broken = s;
i++;
}
if ((original == NULL) || (parity == NULL))
return (ENXIO);
/* Our data stripe is missing. */
if (original->state != GV_SD_UP)
type = REQ_TYPE_DEGRADED;
/* If synchronizing request, just write it if disks are stale. */
if (original->state == GV_SD_STALE && parity->state == GV_SD_STALE &&
bp->bio_pflags & GV_BIO_SYNCREQ && bp->bio_cmd == BIO_WRITE) {
type = REQ_TYPE_NORMAL;
/* Our parity stripe is missing. */
} else if (parity->state != GV_SD_UP) {
/* We cannot take another failure if we're already degraded. */
if (type != REQ_TYPE_NORMAL)
return (ENXIO);
else
type = REQ_TYPE_NOPARITY;
}
wp->length = real_len;
wp->data = addr;
wp->lockbase = real_off;
KASSERT(wp->length >= 0, ("gv_build_raid5_request: wp->length < 0"));
if ((p->flags & GV_PLEX_REBUILDING) && (boff + real_len < p->synced))
type = REQ_TYPE_NORMAL;
if ((p->flags & GV_PLEX_REBUILDING) && (boff + real_len >= p->synced)) {
bioq_disksort(p->rqueue, bp);
*delay = 1;
return (0);
}
switch (bp->bio_cmd) {
case BIO_READ:
/*
* For a degraded read we need to read in all stripes except
* the broken one plus the parity stripe and then recalculate
* the desired data.
*/
if (type == REQ_TYPE_DEGRADED) {
bzero(wp->data, wp->length);
LIST_FOREACH(s, &p->subdisks, in_plex) {
/* Skip the broken subdisk. */
if (s == broken)
continue;
/* Skip growing if within offset. */
if (grow && s->flags & GV_SD_GROW)
continue;
cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
}
/* A normal read can be fulfilled with the original subdisk. */
} else {
cbp = gv_raid5_clone_bio(bp, original, wp, addr, 0);
if (cbp == NULL)
return (ENOMEM);
bioq_insert_tail(p->bqueue, cbp);
}
wp->lockbase = -1;
break;
case BIO_WRITE:
/*
* A degraded write means we cannot write to the original data
* subdisk. Thus we need to read in all valid stripes,
* recalculate the parity from the original data, and then
* write the parity stripe back out.
*/
if (type == REQ_TYPE_DEGRADED) {
/* Read all subdisks. */
LIST_FOREACH(s, &p->subdisks, in_plex) {
/* Skip the broken and the parity subdisk. */
if ((s == broken) || (s == parity))
continue;
/* Skip growing if within offset. */
if (grow && s->flags & GV_SD_GROW)
continue;
cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
}
/* Write the parity data. */
cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
bcopy(addr, cbp->bio_data, wp->length);
wp->parity = cbp;
/*
* When the parity stripe is missing we just write out the data.
*/
} else if (type == REQ_TYPE_NOPARITY) {
cbp = gv_raid5_clone_bio(bp, original, wp, addr, 1);
if (cbp == NULL)
return (ENOMEM);
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
/*
* A normal write request goes to the original subdisk, then we
* read in all other stripes, recalculate the parity and write
* out the parity again.
*/
} else {
/* Read old parity. */
cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
/* Read old data. */
cbp = gv_raid5_clone_bio(bp, original, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
cbp->bio_cmd = BIO_READ;
bioq_insert_tail(p->bqueue, cbp);
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = cbp;
TAILQ_INSERT_TAIL(&wp->bits, bq, queue);
/* Write new data. */
cbp = gv_raid5_clone_bio(bp, original, wp, addr, 1);
if (cbp == NULL)
return (ENOMEM);
/*
* We must not write the new data until the old data
* was read, so hold this BIO back until we're ready
* for it.
*/
wp->waiting = cbp;
/* The final bio for the parity. */
cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1);
if (cbp == NULL)
return (ENOMEM);
/* Remember that this is the BIO for the parity data. */
wp->parity = cbp;
}
break;
default:
return (EINVAL);
}
return (0);
}
/*
* Calculate the offsets in the various subdisks for a RAID5 request. Also take
* care of new subdisks in an expanded RAID5 array.
* XXX: This assumes that the new subdisks are inserted after the others (which
* is okay as long as plex_offset is larger). If subdisks are inserted into the
* plexlist before, we get problems.
*/
static int
gv_raid5_offset(struct gv_plex *p, off_t boff, off_t bcount, off_t *real_off,
off_t *real_len, int *sdno, int *psdno, int growing)
{
struct gv_sd *s;
int sd, psd, sdcount;
off_t len_left, stripeend, stripeoff, stripestart;
sdcount = p->sdcount;
if (growing) {
LIST_FOREACH(s, &p->subdisks, in_plex) {
if (s->flags & GV_SD_GROW)
sdcount--;
}
}
/* The number of the subdisk containing the parity stripe. */
psd = sdcount - 1 - ( boff / (p->stripesize * (sdcount - 1))) %
sdcount;
KASSERT(psdno >= 0, ("gv_raid5_offset: psdno < 0"));
/* Offset of the start address from the start of the stripe. */
stripeoff = boff % (p->stripesize * (sdcount - 1));
KASSERT(stripeoff >= 0, ("gv_raid5_offset: stripeoff < 0"));
/* The number of the subdisk where the stripe resides. */
sd = stripeoff / p->stripesize;
KASSERT(sdno >= 0, ("gv_raid5_offset: sdno < 0"));
/* At or past parity subdisk. */
if (sd >= psd)
sd++;
/* The offset of the stripe on this subdisk. */
stripestart = (boff - stripeoff) / (sdcount - 1);
KASSERT(stripestart >= 0, ("gv_raid5_offset: stripestart < 0"));
stripeoff %= p->stripesize;
/* The offset of the request on this subdisk. */
*real_off = stripestart + stripeoff;
stripeend = stripestart + p->stripesize;
len_left = stripeend - *real_off;
KASSERT(len_left >= 0, ("gv_raid5_offset: len_left < 0"));
*real_len = (bcount <= len_left) ? bcount : len_left;
if (sdno != NULL)
*sdno = sd;
if (psdno != NULL)
*psdno = psd;
return (0);
}
static struct bio *
gv_raid5_clone_bio(struct bio *bp, struct gv_sd *s, struct gv_raid5_packet *wp,
caddr_t addr, int use_wp)
{
struct bio *cbp;
cbp = g_clone_bio(bp);
if (cbp == NULL)
return (NULL);
if (addr == NULL) {
cbp->bio_data = g_malloc(wp->length, M_WAITOK | M_ZERO);
cbp->bio_cflags |= GV_BIO_MALLOC;
} else
cbp->bio_data = addr;
cbp->bio_offset = wp->lockbase + s->drive_offset;
cbp->bio_length = wp->length;
cbp->bio_done = gv_done;
cbp->bio_caller1 = s;
if (use_wp)
cbp->bio_caller2 = wp;
return (cbp);
}