freebsd-dev/sys/geom/geom_io.c
Poul-Henning Kamp 3f521b6022 Add support g_clone_bio() and g_std_done() to spawn multiple children
of a bio and correctly gather status when done.

Sponsored by:	DARPA & NAI Labs.
2002-10-09 07:11:59 +00:00

390 lines
8.3 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#ifndef _KERNEL
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <err.h>
#include <sched.h>
#else
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#endif
#include <sys/errno.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
static struct g_bioq g_bio_run_down;
static struct g_bioq g_bio_run_up;
static struct g_bioq g_bio_idle;
#include <machine/atomic.h>
static void
g_bioq_lock(struct g_bioq *bq)
{
mtx_lock(&bq->bio_queue_lock);
}
static void
g_bioq_unlock(struct g_bioq *bq)
{
mtx_unlock(&bq->bio_queue_lock);
}
#if 0
static void
g_bioq_destroy(struct g_bioq *bq)
{
mtx_destroy(&bq->bio_queue_lock);
}
#endif
static void
g_bioq_init(struct g_bioq *bq)
{
TAILQ_INIT(&bq->bio_queue);
mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
}
static struct bio *
g_bioq_first(struct g_bioq *bq)
{
struct bio *bp;
g_bioq_lock(bq);
bp = TAILQ_FIRST(&bq->bio_queue);
if (bp != NULL) {
TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
bq->bio_queue_length--;
}
g_bioq_unlock(bq);
return (bp);
}
static void
g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
{
g_bioq_lock(rq);
TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
rq->bio_queue_length++;
g_bioq_unlock(rq);
}
struct bio *
g_new_bio(void)
{
struct bio *bp;
bp = g_bioq_first(&g_bio_idle);
if (bp == NULL)
bp = g_malloc(sizeof *bp, M_NOWAIT | M_ZERO);
g_trace(G_T_BIO, "g_new_bio() = %p", bp);
return (bp);
}
void
g_destroy_bio(struct bio *bp)
{
g_trace(G_T_BIO, "g_destroy_bio(%p)", bp);
bzero(bp, sizeof *bp);
g_bioq_enqueue_tail(bp, &g_bio_idle);
}
struct bio *
g_clone_bio(struct bio *bp)
{
struct bio *bp2;
bp2 = g_new_bio();
if (bp2 != NULL) {
bp2->bio_linkage = bp;
bp2->bio_cmd = bp->bio_cmd;
bp2->bio_length = bp->bio_length;
bp2->bio_offset = bp->bio_offset;
bp2->bio_data = bp->bio_data;
bp2->bio_attribute = bp->bio_attribute;
bp->bio_children++; /* XXX: atomic ? */
}
g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2);
return(bp2);
}
void
g_io_init()
{
g_bioq_init(&g_bio_run_down);
g_bioq_init(&g_bio_run_up);
g_bioq_init(&g_bio_idle);
}
int
g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr)
{
struct bio *bp;
int error;
g_trace(G_T_BIO, "bio_setattr(%s)", attr);
bp = g_new_bio();
bp->bio_cmd = BIO_SETATTR;
bp->bio_done = NULL;
bp->bio_attribute = attr;
bp->bio_length = len;
bp->bio_data = ptr;
g_io_request(bp, cp);
error = biowait(bp, "gsetattr");
g_destroy_bio(bp);
return (error);
}
int
g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
{
struct bio *bp;
int error;
g_trace(G_T_BIO, "bio_getattr(%s)", attr);
bp = g_new_bio();
bp->bio_cmd = BIO_GETATTR;
bp->bio_done = NULL;
bp->bio_attribute = attr;
bp->bio_length = *len;
bp->bio_data = ptr;
g_io_request(bp, cp);
error = biowait(bp, "ggetattr");
*len = bp->bio_completed;
g_destroy_bio(bp);
return (error);
}
void
g_io_request(struct bio *bp, struct g_consumer *cp)
{
int error;
off_t excess;
KASSERT(cp != NULL, ("bio_request on thin air"));
error = 0;
bp->bio_from = cp;
bp->bio_to = cp->provider;
bp->bio_error = 0;
bp->bio_completed = 0;
/* begin_stats(&bp->stats); */
atomic_add_int(&cp->biocount, 1);
/* Fail on unattached consumers */
if (bp->bio_to == NULL) {
g_io_deliver(bp, ENXIO);
return;
}
/* Fail if access doesn't allow operation */
switch(bp->bio_cmd) {
case BIO_READ:
case BIO_GETATTR:
if (cp->acr == 0) {
g_io_deliver(bp, EPERM);
return;
}
break;
case BIO_WRITE:
case BIO_DELETE:
if (cp->acw == 0) {
g_io_deliver(bp, EPERM);
return;
}
break;
case BIO_SETATTR:
/* XXX: Should ideally check for (cp->ace == 0) */
if ((cp->acw == 0)) {
#ifdef DIAGNOSTIC
printf("setattr on %s mode (%d,%d,%d)\n",
cp->provider->name,
cp->acr, cp->acw, cp->ace);
#endif
g_io_deliver(bp, EPERM);
return;
}
break;
default:
g_io_deliver(bp, EPERM);
return;
}
/* if provider is marked for error, don't disturb. */
if (bp->bio_to->error) {
g_io_deliver(bp, bp->bio_to->error);
return;
}
switch(bp->bio_cmd) {
case BIO_READ:
case BIO_WRITE:
case BIO_DELETE:
/* Reject requests past the end of media. */
if (bp->bio_offset > bp->bio_to->mediasize) {
g_io_deliver(bp, EIO);
return;
}
/* Truncate requests to the end of providers media. */
excess = bp->bio_offset + bp->bio_length;
if (excess > bp->bio_to->mediasize) {
excess -= bp->bio_to->mediasize;
bp->bio_length -= excess;
}
/* Deliver zero length transfers right here. */
if (bp->bio_length == 0) {
g_io_deliver(bp, 0);
return;
}
break;
default:
break;
}
/* Pass it on down. */
g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
bp, bp->bio_from, bp->bio_from->geom->name,
bp->bio_to, bp->bio_to->name, bp->bio_cmd);
g_bioq_enqueue_tail(bp, &g_bio_run_down);
wakeup(&g_wait_down);
}
void
g_io_deliver(struct bio *bp, int error)
{
g_trace(G_T_BIO,
"g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d",
bp, bp->bio_from, bp->bio_from->geom->name,
bp->bio_to, bp->bio_to->name, bp->bio_cmd, error);
/* finish_stats(&bp->stats); */
bp->bio_error = error;
g_bioq_enqueue_tail(bp, &g_bio_run_up);
wakeup(&g_wait_up);
}
void
g_io_schedule_down(struct thread *tp __unused)
{
struct bio *bp;
for(;;) {
bp = g_bioq_first(&g_bio_run_down);
if (bp == NULL)
break;
bp->bio_to->geom->start(bp);
}
}
void
g_io_schedule_up(struct thread *tp __unused)
{
struct bio *bp;
struct g_consumer *cp;
for(;;) {
bp = g_bioq_first(&g_bio_run_up);
if (bp == NULL)
break;
cp = bp->bio_from;
atomic_add_int(&cp->biocount, -1);
biodone(bp);
}
}
void *
g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
{
struct bio *bp;
void *ptr;
int errorc;
bp = g_new_bio();
bp->bio_cmd = BIO_READ;
bp->bio_done = NULL;
bp->bio_offset = offset;
bp->bio_length = length;
ptr = g_malloc(length, M_WAITOK);
bp->bio_data = ptr;
g_io_request(bp, cp);
errorc = biowait(bp, "gread");
if (error != NULL)
*error = errorc;
g_destroy_bio(bp);
if (errorc) {
g_free(ptr);
ptr = NULL;
}
return (ptr);
}
int
g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
{
struct bio *bp;
int error;
bp = g_new_bio();
bp->bio_cmd = BIO_WRITE;
bp->bio_done = NULL;
bp->bio_offset = offset;
bp->bio_length = length;
bp->bio_data = ptr;
g_io_request(bp, cp);
error = biowait(bp, "gwrite");
g_destroy_bio(bp);
return (error);
}