PSARC 2002/240 ZFS
6338653 Integrate ZFS
PSARC 2004/652 - DKIOCFLUSH
5096886 Write caching disks need mechanism to flush cache to physical media
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/spa_impl.h>
#include <sys/vdev_impl.h>
#include <sys/zio_impl.h>
#include <sys/zio_compress.h>
#include <sys/zio_checksum.h>
static void zio_vdev_io_enter(zio_t *zio);
static void zio_vdev_io_exit(zio_t *zio);
/*
* ==========================================================================
* I/O priority table
* ==========================================================================
*/
uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE] = {
0, /* ZIO_PRIORITY_NOW */
0, /* ZIO_PRIORITY_SYNC_READ */
0, /* ZIO_PRIORITY_SYNC_WRITE */
6, /* ZIO_PRIORITY_ASYNC_READ */
4, /* ZIO_PRIORITY_ASYNC_WRITE */
4, /* ZIO_PRIORITY_FREE */
0, /* ZIO_PRIORITY_CACHE_FILL */
0, /* ZIO_PRIORITY_LOG_WRITE */
10, /* ZIO_PRIORITY_RESILVER */
20, /* ZIO_PRIORITY_SCRUB */
};
/*
* ==========================================================================
* I/O type descriptions
* ==========================================================================
*/
char *zio_type_name[ZIO_TYPES] = {
"null", "read", "write", "free", "claim", "ioctl" };
/* At or above this size, force gang blocking - for testing */
uint64_t zio_gang_bang = SPA_MAXBLOCKSIZE + 1;
typedef struct zio_sync_pass {
int zp_defer_free; /* defer frees after this pass */
int zp_dontcompress; /* don't compress after this pass */
int zp_rewrite; /* rewrite new bps after this pass */
} zio_sync_pass_t;
zio_sync_pass_t zio_sync_pass = {
1, /* zp_defer_free */
4, /* zp_dontcompress */
1, /* zp_rewrite */
};
/*
* ==========================================================================
* I/O kmem caches
* ==========================================================================
*/
kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
void
zio_init(void)
{
size_t c;
/*
* For small buffers, we want a cache for each multiple of
* SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache
* for each quarter-power of 2. For large buffers, we want
* a cache for each multiple of PAGESIZE.
*/
for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
size_t p2 = size;
size_t align = 0;
while (p2 & (p2 - 1))
p2 &= p2 - 1;
if (size <= 4 * SPA_MINBLOCKSIZE) {
align = SPA_MINBLOCKSIZE;
} else if (P2PHASE(size, PAGESIZE) == 0) {
align = PAGESIZE;
} else if (P2PHASE(size, p2 >> 2) == 0) {
align = p2 >> 2;
}
if (align != 0) {
char name[30];
(void) sprintf(name, "zio_buf_%lu", size);
zio_buf_cache[c] = kmem_cache_create(name, size,
align, NULL, NULL, NULL, NULL, NULL, 0);
dprintf("creating cache for size %5lx align %5lx\n",
size, align);
}
}
while (--c != 0) {
ASSERT(zio_buf_cache[c] != NULL);
if (zio_buf_cache[c - 1] == NULL)
zio_buf_cache[c - 1] = zio_buf_cache[c];
}
}
void
zio_fini(void)
{
size_t c;
kmem_cache_t *last_cache = NULL;
for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
if (zio_buf_cache[c] != last_cache) {
last_cache = zio_buf_cache[c];
kmem_cache_destroy(zio_buf_cache[c]);
}
zio_buf_cache[c] = NULL;
}
}
/*
* ==========================================================================
* Allocate and free I/O buffers
* ==========================================================================
*/
void *
zio_buf_alloc(size_t size)
{
size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
return (kmem_cache_alloc(zio_buf_cache[c], KM_SLEEP));
}
void
zio_buf_free(void *buf, size_t size)
{
size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
kmem_cache_free(zio_buf_cache[c], buf);
}
/*
* ==========================================================================
* Push and pop I/O transform buffers
* ==========================================================================
*/
static void
zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize)
{
zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
zt->zt_data = data;
zt->zt_size = size;
zt->zt_bufsize = bufsize;
zt->zt_next = zio->io_transform_stack;
zio->io_transform_stack = zt;
zio->io_data = data;
zio->io_size = size;
}
static void
zio_pop_transform(zio_t *zio, void **data, uint64_t *size, uint64_t *bufsize)
{
zio_transform_t *zt = zio->io_transform_stack;
*data = zt->zt_data;
*size = zt->zt_size;
*bufsize = zt->zt_bufsize;
zio->io_transform_stack = zt->zt_next;
kmem_free(zt, sizeof (zio_transform_t));
if ((zt = zio->io_transform_stack) != NULL) {
zio->io_data = zt->zt_data;
zio->io_size = zt->zt_size;
}
}
static void
zio_clear_transform_stack(zio_t *zio)
{
void *data;
uint64_t size, bufsize;
ASSERT(zio->io_transform_stack != NULL);
zio_pop_transform(zio, &data, &size, &bufsize);
while (zio->io_transform_stack != NULL) {
zio_buf_free(data, bufsize);
zio_pop_transform(zio, &data, &size, &bufsize);
}
}
/*
* ==========================================================================
* Create the various types of I/O (read, write, free)
* ==========================================================================
*/
static zio_t *
zio_create(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
void *data, uint64_t size, zio_done_func_t *done, void *private,
zio_type_t type, int priority, int flags, uint8_t stage, uint32_t pipeline)
{
zio_t *zio;
ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0);
zio = kmem_zalloc(sizeof (zio_t), KM_SLEEP);
zio->io_parent = pio;
zio->io_spa = spa;
zio->io_txg = txg;
if (bp != NULL) {
zio->io_bp = bp;
zio->io_bp_copy = *bp;
zio->io_bp_orig = *bp;
/* XXBP - Need to inherit this when it matters */
zio->io_dva_index = 0;
}
zio->io_done = done;
zio->io_private = private;
zio->io_type = type;
zio->io_priority = priority;
zio->io_stage = stage;
zio->io_pipeline = pipeline;
zio->io_async_stages = ZIO_ASYNC_PIPELINE_STAGES;
zio->io_timestamp = lbolt64;
zio->io_flags = flags;
zio_push_transform(zio, data, size, size);
if (pio == NULL) {
if (!(flags & ZIO_FLAG_CONFIG_HELD))
spa_config_enter(zio->io_spa, RW_READER);
zio->io_root = zio;
} else {
zio->io_root = pio->io_root;
mutex_enter(&pio->io_lock);
if (stage < ZIO_STAGE_READY)
pio->io_children_notready++;
pio->io_children_notdone++;
zio->io_sibling_next = pio->io_child;
zio->io_sibling_prev = NULL;
if (pio->io_child != NULL)
pio->io_child->io_sibling_prev = zio;
pio->io_child = zio;
mutex_exit(&pio->io_lock);
}
return (zio);
}
zio_t *
zio_null(zio_t *pio, spa_t *spa, zio_done_func_t *done, void *private,
int flags)
{
zio_t *zio;
zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, ZIO_STAGE_OPEN,
ZIO_WAIT_FOR_CHILDREN_PIPELINE);
return (zio);
}
zio_t *
zio_root(spa_t *spa, zio_done_func_t *done, void *private, int flags)
{
return (zio_null(NULL, spa, done, private, flags));
}
zio_t *
zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
uint64_t size, zio_done_func_t *done, void *private,
int priority, int flags)
{
zio_t *zio;
dva_t *dva;
ASSERT3U(size, ==, BP_GET_LSIZE(bp));
zio = zio_create(pio, spa, bp->blk_birth, bp, data, size, done, private,
ZIO_TYPE_READ, priority, flags, ZIO_STAGE_OPEN, ZIO_READ_PIPELINE);
/*
* Work off our copy of the bp so the caller can free it.
*/
zio->io_bp = &zio->io_bp_copy;
bp = zio->io_bp;
dva = ZIO_GET_DVA(zio);
if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) {
uint64_t csize = BP_GET_PSIZE(bp);
void *cbuf = zio_buf_alloc(csize);
zio_push_transform(zio, cbuf, csize, csize);
zio->io_pipeline |= 1U << ZIO_STAGE_READ_DECOMPRESS;
}
if (DVA_GET_GANG(dva)) {
uint64_t gsize = SPA_GANGBLOCKSIZE;
void *gbuf = zio_buf_alloc(gsize);
zio_push_transform(zio, gbuf, gsize, gsize);
zio->io_pipeline |= 1U << ZIO_STAGE_READ_GANG_MEMBERS;
}
return (zio);
}
zio_t *
zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
zio_done_func_t *done, void *private, int priority, int flags)
{
zio_t *zio;
ASSERT(checksum >= ZIO_CHECKSUM_OFF &&
checksum < ZIO_CHECKSUM_FUNCTIONS);
ASSERT(compress >= ZIO_COMPRESS_OFF &&
compress < ZIO_COMPRESS_FUNCTIONS);
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags,
ZIO_STAGE_OPEN, ZIO_WRITE_PIPELINE);
zio->io_checksum = checksum;
zio->io_compress = compress;
if (compress != ZIO_COMPRESS_OFF)
zio->io_async_stages |= 1U << ZIO_STAGE_WRITE_COMPRESS;
if (bp->blk_birth != txg) {
/* XXX the bp usually (always?) gets re-zeroed later */
BP_ZERO(bp);
BP_SET_LSIZE(bp, size);
BP_SET_PSIZE(bp, size);
}
return (zio);
}
zio_t *
zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
zio_done_func_t *done, void *private, int priority, int flags)
{
zio_t *zio;
/* XXBP - We need to re-evaluate when to insert pipeline stages */
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags,
ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
zio->io_checksum = checksum;
zio->io_compress = ZIO_COMPRESS_OFF;
return (zio);
}
static zio_t *
zio_write_allocate(zio_t *pio, spa_t *spa, int checksum,
uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
zio_done_func_t *done, void *private, int priority, int flags)
{
zio_t *zio;
BP_ZERO(bp);
BP_SET_LSIZE(bp, size);
BP_SET_PSIZE(bp, size);
BP_SET_COMPRESS(bp, ZIO_COMPRESS_OFF);
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags,
ZIO_STAGE_OPEN, ZIO_WRITE_ALLOCATE_PIPELINE);
zio->io_checksum = checksum;
zio->io_compress = ZIO_COMPRESS_OFF;
return (zio);
}
zio_t *
zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
zio_done_func_t *done, void *private)
{
zio_t *zio;
ASSERT(!BP_IS_HOLE(bp));
if (txg == spa->spa_syncing_txg &&
spa->spa_sync_pass > zio_sync_pass.zp_defer_free) {
bplist_enqueue_deferred(&spa->spa_sync_bplist, bp);
return (zio_null(pio, spa, NULL, NULL, 0));
}
/* XXBP - We need to re-evaluate when to insert pipeline stages */
zio = zio_create(pio, spa, txg, bp, NULL, 0, done, private,
ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, 0,
ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE);
zio->io_bp = &zio->io_bp_copy;
return (zio);
}
zio_t *
zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
zio_done_func_t *done, void *private)
{
zio_t *zio;
/*
* A claim is an allocation of a specific block. Claims are needed
* to support immediate writes in the intent log. The issue is that
* immediate writes contain committed data, but in a txg that was
* *not* committed. Upon opening the pool after an unclean shutdown,
* the intent log claims all blocks that contain immediate write data
* so that the SPA knows they're in use.
*
* All claims *must* be resolved in the first txg -- before the SPA
* starts allocating blocks -- so that nothing is allocated twice.
*/
ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa));
ASSERT3U(spa_first_txg(spa), <=, txg);
/* XXBP - We need to re-evaluate when to insert pipeline stages */
zio = zio_create(pio, spa, txg, bp, NULL, 0, done, private,
ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, 0,
ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
zio->io_bp = &zio->io_bp_copy;
return (zio);
}
zio_t *
zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
zio_done_func_t *done, void *private, int priority, int flags)
{
zio_t *zio;
int c;
if (vd->vdev_children == 0) {
zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
ZIO_TYPE_IOCTL, priority, flags,
ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
zio->io_vd = vd;
zio->io_cmd = cmd;
} else {
zio = zio_null(pio, spa, NULL, NULL, flags);
for (c = 0; c < vd->vdev_children; c++)
zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
done, private, priority, flags));
}
return (zio);
}
static void
zio_phys_bp_init(vdev_t *vd, blkptr_t *bp, uint64_t offset, uint64_t size,
int checksum)
{
ASSERT(vd->vdev_children == 0);
ASSERT(size <= SPA_MAXBLOCKSIZE);
ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0);
ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
ASSERT(offset + size <= VDEV_LABEL_START_SIZE ||
offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
ASSERT3U(offset + size, <=, vd->vdev_psize);
BP_ZERO(bp);
BP_SET_LSIZE(bp, size);
BP_SET_PSIZE(bp, size);
BP_SET_CHECKSUM(bp, checksum);
BP_SET_COMPRESS(bp, ZIO_COMPRESS_OFF);
BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
if (checksum != ZIO_CHECKSUM_OFF)
ZIO_SET_CHECKSUM(&bp->blk_cksum, offset, 0, 0, 0);
}
zio_t *
zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
void *data, int checksum, zio_done_func_t *done, void *private,
int priority, int flags)
{
zio_t *zio;
blkptr_t blk;
zio_phys_bp_init(vd, &blk, offset, size, checksum);
zio = zio_create(pio, vd->vdev_spa, 0, &blk, data, size, done, private,
ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL,
ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
zio->io_vd = vd;
zio->io_offset = offset;
/*
* Work off our copy of the bp so the caller can free it.
*/
zio->io_bp = &zio->io_bp_copy;
return (zio);
}
zio_t *
zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
void *data, int checksum, zio_done_func_t *done, void *private,
int priority, int flags)
{
zio_block_tail_t *zbt;
void *wbuf;
zio_t *zio;
blkptr_t blk;
zio_phys_bp_init(vd, &blk, offset, size, checksum);
zio = zio_create(pio, vd->vdev_spa, 0, &blk, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL,
ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
zio->io_vd = vd;
zio->io_offset = offset;
zio->io_bp = &zio->io_bp_copy;
zio->io_checksum = checksum;
if (zio_checksum_table[checksum].ci_zbt) {
/*
* zbt checksums are necessarily destructive -- they modify
* one word of the write buffer to hold the verifier/checksum.
* Therefore, we must make a local copy in case the data is
* being written to multiple places.
*/
wbuf = zio_buf_alloc(size);
bcopy(data, wbuf, size);
zio_push_transform(zio, wbuf, size, size);
zbt = (zio_block_tail_t *)((char *)wbuf + size) - 1;
zbt->zbt_cksum = blk.blk_cksum;
}
return (zio);
}
/*
* Create a child I/O to do some work for us. It has no associated bp.
*/
zio_t *
zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
void *data, uint64_t size, int type, int priority, int flags,
zio_done_func_t *done, void *private)
{
uint32_t pipeline = ZIO_VDEV_CHILD_PIPELINE;
zio_t *cio;
if (type == ZIO_TYPE_READ && bp != NULL) {
/*
* If we have the bp, then the child should perform the
* checksum and the parent need not. This pushes error
* detection as close to the leaves as possible and
* eliminates redundant checksums in the interior nodes.
*/
pipeline |= 1U << ZIO_STAGE_CHECKSUM_VERIFY;
zio->io_pipeline &= ~(1U << ZIO_STAGE_CHECKSUM_VERIFY);
}
cio = zio_create(zio, zio->io_spa, zio->io_txg, bp, data, size,
done, private, type, priority,
(zio->io_flags & ZIO_FLAG_VDEV_INHERIT) | ZIO_FLAG_CANFAIL | flags,
ZIO_STAGE_VDEV_IO_SETUP - 1, pipeline);
cio->io_vd = vd;
cio->io_offset = offset;
return (cio);
}
/*
* ==========================================================================
* Initiate I/O, either sync or async
* ==========================================================================
*/
int
zio_wait(zio_t *zio)
{
int error;
ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
zio->io_waiter = curthread;
zio_next_stage_async(zio);
mutex_enter(&zio->io_lock);
while (zio->io_stalled != ZIO_STAGE_DONE)
cv_wait(&zio->io_cv, &zio->io_lock);
mutex_exit(&zio->io_lock);
error = zio->io_error;
kmem_free(zio, sizeof (zio_t));
return (error);
}
void
zio_nowait(zio_t *zio)
{
zio_next_stage_async(zio);
}
/*
* ==========================================================================
* I/O pipeline interlocks: parent/child dependency scoreboarding
* ==========================================================================
*/
static void
zio_wait_for_children(zio_t *zio, uint32_t stage, uint64_t *countp)
{
mutex_enter(&zio->io_lock);
if (*countp == 0) {
ASSERT(zio->io_stalled == 0);
mutex_exit(&zio->io_lock);
zio_next_stage(zio);
} else {
if (zio->io_stage == ZIO_STAGE_VDEV_IO_START)
zio_vdev_io_exit(zio);
zio->io_stalled = stage;
mutex_exit(&zio->io_lock);
}
}
static void
zio_notify_parent(zio_t *zio, uint32_t stage, uint64_t *countp)
{
zio_t *pio = zio->io_parent;
mutex_enter(&pio->io_lock);
if (pio->io_error == 0 && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
pio->io_error = zio->io_error;
if (--*countp == 0 && pio->io_stalled == stage) {
if (pio->io_stage == ZIO_STAGE_VDEV_IO_START)
zio_vdev_io_enter(pio);
pio->io_stalled = 0;
mutex_exit(&pio->io_lock);
zio_next_stage_async(pio);
} else {
mutex_exit(&pio->io_lock);
}
}
static void
zio_wait_children_ready(zio_t *zio)
{
zio_wait_for_children(zio, ZIO_STAGE_WAIT_CHILDREN_READY,
&zio->io_children_notready);
}
void
zio_wait_children_done(zio_t *zio)
{
zio_wait_for_children(zio, ZIO_STAGE_WAIT_CHILDREN_DONE,
&zio->io_children_notdone);
}
static void
zio_ready(zio_t *zio)
{
zio_t *pio = zio->io_parent;
if (pio != NULL)
zio_notify_parent(zio, ZIO_STAGE_WAIT_CHILDREN_READY,
&pio->io_children_notready);
if (zio->io_bp)
zio->io_bp_copy = *zio->io_bp;
zio_next_stage(zio);
}
static void
zio_done(zio_t *zio)
{
zio_t *pio = zio->io_parent;
spa_t *spa = zio->io_spa;
blkptr_t *bp = zio->io_bp;
vdev_t *vd = zio->io_vd;
char blkbuf[300];
ASSERT(zio->io_children_notready == 0);
ASSERT(zio->io_children_notdone == 0);
if (bp != NULL) {
ASSERT(bp->blk_pad[0] == 0);
ASSERT(bp->blk_pad[1] == 0);
ASSERT(bp->blk_pad[2] == 0);
ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0);
if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) &&
!(zio->io_flags & ZIO_FLAG_IO_REPAIR))
ASSERT(!BP_SHOULD_BYTESWAP(bp));
}
if (vd != NULL)
vdev_stat_update(zio);
if (zio->io_error) {
sprintf_blkptr(blkbuf, bp ? bp : &zio->io_bp_copy);
dprintf("ZFS: %s (%s on %s off %llx: zio %p %s): error %d\n",
zio->io_error == ECKSUM ? "bad checksum" : "I/O failure",
zio_type_name[zio->io_type],
vdev_description(vd),
(u_longlong_t)zio->io_offset,
zio, blkbuf, zio->io_error);
}
if (zio->io_numerrors != 0 && zio->io_type == ZIO_TYPE_WRITE) {
sprintf_blkptr(blkbuf, bp ? bp : &zio->io_bp_copy);
dprintf("ZFS: %s (%s on %s off %llx: zio %p %s): %d errors\n",
"partial write",
zio_type_name[zio->io_type],
vdev_description(vd),
(u_longlong_t)zio->io_offset,
zio, blkbuf, zio->io_numerrors);
}
if (zio->io_error && !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
sprintf_blkptr(blkbuf, bp ? bp : &zio->io_bp_copy);
panic("ZFS: %s (%s on %s off %llx: zio %p %s): error %d",
zio->io_error == ECKSUM ? "bad checksum" : "I/O failure",
zio_type_name[zio->io_type],
vdev_description(vd),
(u_longlong_t)zio->io_offset,
zio, blkbuf, zio->io_error);
}
zio_clear_transform_stack(zio);
if (zio->io_done)
zio->io_done(zio);
ASSERT(zio->io_delegate_list == NULL);
ASSERT(zio->io_delegate_next == NULL);
if (pio != NULL) {
zio_t *next, *prev;
mutex_enter(&pio->io_lock);
next = zio->io_sibling_next;
prev = zio->io_sibling_prev;
if (next != NULL)
next->io_sibling_prev = prev;
if (prev != NULL)
prev->io_sibling_next = next;
if (pio->io_child == zio)
pio->io_child = next;
mutex_exit(&pio->io_lock);
zio_notify_parent(zio, ZIO_STAGE_WAIT_CHILDREN_DONE,
&pio->io_children_notdone);
}
if (pio == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_HELD))
spa_config_exit(spa);
if (zio->io_waiter != NULL) {
mutex_enter(&zio->io_lock);
ASSERT(zio->io_stage == ZIO_STAGE_DONE);
zio->io_stalled = zio->io_stage;
cv_broadcast(&zio->io_cv);
mutex_exit(&zio->io_lock);
} else {
kmem_free(zio, sizeof (zio_t));
}
}
/*
* ==========================================================================
* Compression support
* ==========================================================================
*/
static void
zio_write_compress(zio_t *zio)
{
int compress = zio->io_compress;
blkptr_t *bp = zio->io_bp;
void *cbuf;
uint64_t lsize = zio->io_size;
uint64_t csize = lsize;
uint64_t cbufsize = 0;
int pass;
if (bp->blk_birth == zio->io_txg) {
/*
* We're rewriting an existing block, which means we're
* working on behalf of spa_sync(). For spa_sync() to
* converge, it must eventually be the case that we don't
* have to allocate new blocks. But compression changes
* the blocksize, which forces a reallocate, and makes
* convergence take longer. Therefore, after the first
* few passes, stop compressing to ensure convergence.
*/
pass = spa_sync_pass(zio->io_spa);
if (pass > zio_sync_pass.zp_dontcompress)
compress = ZIO_COMPRESS_OFF;
} else {
ASSERT(BP_IS_HOLE(bp));
pass = 1;
}
if (compress != ZIO_COMPRESS_OFF)
if (!zio_compress_data(compress, zio->io_data, zio->io_size,
&cbuf, &csize, &cbufsize))
compress = ZIO_COMPRESS_OFF;
if (compress != ZIO_COMPRESS_OFF && csize != 0)
zio_push_transform(zio, cbuf, csize, cbufsize);
/*
* The final pass of spa_sync() must be all rewrites, but the first
* few passes offer a trade-off: allocating blocks defers convergence,
* but newly allocated blocks are sequential, so they can be written
* to disk faster. Therefore, we allow the first few passes of
* spa_sync() to reallocate new blocks, but force rewrites after that.
* There should only be a handful of blocks after pass 1 in any case.
*/
if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == csize &&
pass > zio_sync_pass.zp_rewrite) {
ASSERT(csize != 0);
ASSERT3U(BP_GET_COMPRESS(bp), ==, compress);
ASSERT3U(BP_GET_LSIZE(bp), ==, lsize);
zio->io_pipeline = ZIO_REWRITE_PIPELINE;
} else {
if (bp->blk_birth == zio->io_txg) {
ASSERT3U(BP_GET_LSIZE(bp), ==, lsize);
bzero(bp, sizeof (blkptr_t));
}
if (csize == 0) {
BP_ZERO(bp);
zio->io_pipeline = ZIO_WAIT_FOR_CHILDREN_PIPELINE;
} else {
BP_SET_LSIZE(bp, lsize);
BP_SET_PSIZE(bp, csize);
BP_SET_COMPRESS(bp, compress);
zio->io_pipeline = ZIO_WRITE_ALLOCATE_PIPELINE;
}
}
zio_next_stage(zio);
}
static void
zio_read_decompress(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
void *data;
uint64_t size;
uint64_t bufsize;
int compress = BP_GET_COMPRESS(bp);
ASSERT(compress != ZIO_COMPRESS_OFF);
zio_pop_transform(zio, &data, &size, &bufsize);
if (zio_decompress_data(compress, data, size,
zio->io_data, zio->io_size))
zio->io_error = EIO;
zio_buf_free(data, bufsize);
zio_next_stage(zio);
}
/*
* ==========================================================================
* Gang block support
* ==========================================================================
*/
static void
zio_gang_pipeline(zio_t *zio)
{
/*
* By default, the pipeline assumes that we're dealing with a gang
* block. If we're not, strip out any gang-specific stages.
*/
if (!DVA_GET_GANG(ZIO_GET_DVA(zio)))
zio->io_pipeline &= ~ZIO_GANG_STAGES;
zio_next_stage(zio);
}
static void
zio_gang_byteswap(zio_t *zio)
{
ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
if (BP_SHOULD_BYTESWAP(zio->io_bp))
byteswap_uint64_array(zio->io_data, zio->io_size);
}
static void
zio_get_gang_header(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
uint64_t gsize = SPA_GANGBLOCKSIZE;
void *gbuf = zio_buf_alloc(gsize);
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
zio_push_transform(zio, gbuf, gsize, gsize);
zio_nowait(zio_create(zio, zio->io_spa, bp->blk_birth, bp, gbuf, gsize,
NULL, NULL, ZIO_TYPE_READ, zio->io_priority,
zio->io_flags & ZIO_FLAG_GANG_INHERIT,
ZIO_STAGE_OPEN, ZIO_READ_PIPELINE));
zio_wait_children_done(zio);
}
static void
zio_read_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize, loff, lsize;
int i;
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
zio_gang_byteswap(zio);
zio_pop_transform(zio, (void **)&gbh, &gsize, &gbufsize);
for (loff = 0, i = 0; loff != zio->io_size; loff += lsize, i++) {
blkptr_t *gbp = &gbh->zg_blkptr[i];
lsize = BP_GET_PSIZE(gbp);
ASSERT(BP_GET_COMPRESS(gbp) == ZIO_COMPRESS_OFF);
ASSERT3U(lsize, ==, BP_GET_LSIZE(gbp));
ASSERT3U(loff + lsize, <=, zio->io_size);
ASSERT(i < SPA_GBH_NBLKPTRS);
ASSERT(!BP_IS_HOLE(gbp));
zio_nowait(zio_read(zio, zio->io_spa, gbp,
(char *)zio->io_data + loff, lsize, NULL, NULL,
zio->io_priority, zio->io_flags & ZIO_FLAG_GANG_INHERIT));
}
zio_buf_free(gbh, gbufsize);
zio_wait_children_done(zio);
}
static void
zio_rewrite_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize, loff, lsize;
int i;
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
ASSERT3U(zio->io_size, ==, SPA_GANGBLOCKSIZE);
zio_gang_byteswap(zio);
zio_pop_transform(zio, (void **)&gbh, &gsize, &gbufsize);
ASSERT(gsize == gbufsize);
for (loff = 0, i = 0; loff != zio->io_size; loff += lsize, i++) {
blkptr_t *gbp = &gbh->zg_blkptr[i];
lsize = BP_GET_PSIZE(gbp);
ASSERT(BP_GET_COMPRESS(gbp) == ZIO_COMPRESS_OFF);
ASSERT3U(lsize, ==, BP_GET_LSIZE(gbp));
ASSERT3U(loff + lsize, <=, zio->io_size);
ASSERT(i < SPA_GBH_NBLKPTRS);
ASSERT(!BP_IS_HOLE(gbp));
zio_nowait(zio_rewrite(zio, zio->io_spa, zio->io_checksum,
zio->io_txg, gbp, (char *)zio->io_data + loff, lsize,
NULL, NULL, zio->io_priority, zio->io_flags));
}
zio_push_transform(zio, gbh, gsize, gbufsize);
zio_wait_children_ready(zio);
}
static void
zio_free_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize;
int i;
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
zio_gang_byteswap(zio);
zio_pop_transform(zio, (void **)&gbh, &gsize, &gbufsize);
for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
blkptr_t *gbp = &gbh->zg_blkptr[i];
if (BP_IS_HOLE(gbp))
continue;
zio_nowait(zio_free(zio, zio->io_spa, zio->io_txg,
gbp, NULL, NULL));
}
zio_buf_free(gbh, gbufsize);
zio_next_stage(zio);
}
static void
zio_claim_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize;
int i;
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
zio_gang_byteswap(zio);
zio_pop_transform(zio, (void **)&gbh, &gsize, &gbufsize);
for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
blkptr_t *gbp = &gbh->zg_blkptr[i];
if (BP_IS_HOLE(gbp))
continue;
zio_nowait(zio_claim(zio, zio->io_spa, zio->io_txg,
gbp, NULL, NULL));
}
zio_buf_free(gbh, gbufsize);
zio_next_stage(zio);
}
static void
zio_write_allocate_gang_member_done(zio_t *zio)
{
zio_t *pio = zio->io_parent;
dva_t *cdva = ZIO_GET_DVA(zio);
dva_t *pdva = ZIO_GET_DVA(pio);
uint64_t asize;
ASSERT(DVA_GET_GANG(pdva));
/* XXBP - Need to be careful here with multiple DVAs */
mutex_enter(&pio->io_lock);
asize = DVA_GET_ASIZE(pdva);
asize += DVA_GET_ASIZE(cdva);
DVA_SET_ASIZE(pdva, asize);
mutex_exit(&pio->io_lock);
}
static void
zio_write_allocate_gang_members(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dva_t *dva = ZIO_GET_DVA(zio);
zio_gbh_phys_t *gbh;
uint64_t resid = zio->io_size;
uint64_t maxalloc = P2ROUNDUP(zio->io_size >> 1, SPA_MINBLOCKSIZE);
uint64_t gsize, loff, lsize;
uint32_t gbps_left;
int error;
int i;
gsize = SPA_GANGBLOCKSIZE;
gbps_left = SPA_GBH_NBLKPTRS;
error = metaslab_alloc(zio->io_spa, gsize, dva, zio->io_txg);
if (error == ENOSPC)
panic("can't allocate gang block header");
ASSERT(error == 0);
DVA_SET_GANG(dva, 1);
bp->blk_birth = zio->io_txg;
gbh = zio_buf_alloc(gsize);
bzero(gbh, gsize);
for (loff = 0, i = 0; loff != zio->io_size;
loff += lsize, resid -= lsize, gbps_left--, i++) {
blkptr_t *gbp = &gbh->zg_blkptr[i];
dva = &gbp->blk_dva[0];
ASSERT(gbps_left != 0);
maxalloc = MIN(maxalloc, resid);
while (resid <= maxalloc * gbps_left) {
error = metaslab_alloc(zio->io_spa, maxalloc, dva,
zio->io_txg);
if (error == 0)
break;
ASSERT3U(error, ==, ENOSPC);
if (maxalloc == SPA_MINBLOCKSIZE)
panic("really out of space");
maxalloc = P2ROUNDUP(maxalloc >> 1, SPA_MINBLOCKSIZE);
}
if (resid <= maxalloc * gbps_left) {
lsize = maxalloc;
BP_SET_LSIZE(gbp, lsize);
BP_SET_PSIZE(gbp, lsize);
BP_SET_COMPRESS(gbp, ZIO_COMPRESS_OFF);
gbp->blk_birth = zio->io_txg;
zio_nowait(zio_rewrite(zio, zio->io_spa,
zio->io_checksum, zio->io_txg, gbp,
(char *)zio->io_data + loff, lsize,
zio_write_allocate_gang_member_done, NULL,
zio->io_priority, zio->io_flags));
} else {
lsize = P2ROUNDUP(resid / gbps_left, SPA_MINBLOCKSIZE);
ASSERT(lsize != SPA_MINBLOCKSIZE);
zio_nowait(zio_write_allocate(zio, zio->io_spa,
zio->io_checksum, zio->io_txg, gbp,
(char *)zio->io_data + loff, lsize,
zio_write_allocate_gang_member_done, NULL,
zio->io_priority, zio->io_flags));
}
}
ASSERT(resid == 0 && loff == zio->io_size);
zio->io_pipeline |= 1U << ZIO_STAGE_GANG_CHECKSUM_GENERATE;
zio_push_transform(zio, gbh, gsize, gsize);
zio_wait_children_done(zio);
}
/*
* ==========================================================================
* Allocate and free blocks
* ==========================================================================
*/
static void
zio_dva_allocate(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dva_t *dva = ZIO_GET_DVA(zio);
int error;
ASSERT(BP_IS_HOLE(bp));
/* For testing, make some blocks above a certain size be gang blocks */
if (zio->io_size >= zio_gang_bang && (lbolt & 0x3) == 0) {
zio_write_allocate_gang_members(zio);
return;
}
ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
error = metaslab_alloc(zio->io_spa, zio->io_size, dva, zio->io_txg);
if (error == 0) {
bp->blk_birth = zio->io_txg;
} else if (error == ENOSPC) {
if (zio->io_size == SPA_MINBLOCKSIZE)
panic("really, truly out of space");
zio_write_allocate_gang_members(zio);
return;
} else {
zio->io_error = error;
}
zio_next_stage(zio);
}
static void
zio_dva_free(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dva_t *dva = ZIO_GET_DVA(zio);
ASSERT(!BP_IS_HOLE(bp));
metaslab_free(zio->io_spa, dva, zio->io_txg);
BP_ZERO(bp);
zio_next_stage(zio);
}
static void
zio_dva_claim(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dva_t *dva = ZIO_GET_DVA(zio);
ASSERT(!BP_IS_HOLE(bp));
zio->io_error = metaslab_claim(zio->io_spa, dva, zio->io_txg);
zio_next_stage(zio);
}
static void
zio_dva_translate(zio_t *zio)
{
spa_t *spa = zio->io_spa;
dva_t *dva = ZIO_GET_DVA(zio);
uint64_t vdev = DVA_GET_VDEV(dva);
uint64_t offset = DVA_GET_OFFSET(dva);
ASSERT3U(zio->io_size, ==, ZIO_GET_IOSIZE(zio));
zio->io_offset = offset;
if ((zio->io_vd = vdev_lookup_top(spa, vdev)) == NULL)
zio->io_error = ENXIO;
else if (offset + zio->io_size > zio->io_vd->vdev_asize)
zio->io_error = EOVERFLOW;
zio_next_stage(zio);
}
/*
* ==========================================================================
* Read and write to physical devices
* ==========================================================================
*/
static void
zio_vdev_io_enter(zio_t *zio)
{
vdev_t *tvd = zio->io_vd->vdev_top;
mutex_enter(&tvd->vdev_io_lock);
ASSERT(zio->io_pending.list_next == NULL);
list_insert_tail(&tvd->vdev_io_pending, zio);
mutex_exit(&tvd->vdev_io_lock);
}
static void
zio_vdev_io_exit(zio_t *zio)
{
vdev_t *tvd = zio->io_vd->vdev_top;
mutex_enter(&tvd->vdev_io_lock);
ASSERT(zio->io_pending.list_next != NULL);
list_remove(&tvd->vdev_io_pending, zio);
if (list_head(&tvd->vdev_io_pending) == NULL)
cv_broadcast(&tvd->vdev_io_cv);
mutex_exit(&tvd->vdev_io_lock);
}
static void
zio_vdev_io_retry(void *vdarg)
{
vdev_t *vd = vdarg;
zio_t *zio, *zq;
ASSERT(vd == vd->vdev_top);
/* XXPOLICY */
delay(hz);
vdev_reopen(vd, &zq);
while ((zio = zq) != NULL) {
zq = zio->io_retry_next;
zio->io_retry_next = NULL;
dprintf("async retry #%d for I/O to %s offset %llx\n",
zio->io_retries, vdev_description(vd), zio->io_offset);
zio_next_stage_async(zio);
}
}
static void
zio_vdev_io_setup(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
/* XXPOLICY */
if (zio->io_retries == 0 && vd == vd->vdev_top)
zio->io_flags |= ZIO_FLAG_FAILFAST;
if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && vd->vdev_children == 0) {
zio->io_flags |= ZIO_FLAG_PHYSICAL;
zio->io_offset += VDEV_LABEL_START_SIZE;
}
zio_vdev_io_enter(zio);
zio_next_stage(zio);
}
static void
zio_vdev_io_start(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
ASSERT(P2PHASE(zio->io_offset, 1ULL << zio->io_vd->vdev_ashift) == 0);
ASSERT(P2PHASE(zio->io_size, 1ULL << zio->io_vd->vdev_ashift) == 0);
ASSERT(bp == NULL || ZIO_GET_IOSIZE(zio) == zio->io_size);
ASSERT(zio->io_type != ZIO_TYPE_WRITE || (spa_mode & FWRITE));
vdev_io_start(zio);
/* zio_next_stage_async() gets called from io completion interrupt */
}
static void
zio_vdev_io_done(zio_t *zio)
{
vdev_io_done(zio);
}
/* XXPOLICY */
static boolean_t
zio_should_retry(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
if (zio->io_error == 0)
return (B_FALSE);
if (zio->io_delegate_list != NULL)
return (B_FALSE);
if (vd != vd->vdev_top)
return (B_FALSE);
if (zio->io_flags & ZIO_FLAG_DONT_RETRY)
return (B_FALSE);
if (zio->io_retries > 300 &&
(zio->io_flags & (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL)))
return (B_FALSE);
if (zio->io_retries > 1 &&
(zio->io_error == ECKSUM || zio->io_error == ENXIO))
return (B_FALSE);
return (B_TRUE);
}
static void
zio_vdev_io_assess(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_t *tvd = vd->vdev_top;
zio_vdev_io_exit(zio);
ASSERT(zio->io_vsd == NULL);
/*
* If the I/O failed, determine whether we should attempt to retry it.
*/
/* XXPOLICY */
if (zio_should_retry(zio)) {
zio_t *zq;
ASSERT(tvd == vd);
ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE));
zio->io_retries++;
zio->io_error = 0;
zio->io_flags &= ZIO_FLAG_VDEV_INHERIT;
/* XXPOLICY */
zio->io_flags &= ~ZIO_FLAG_FAILFAST;
zio->io_flags |= ZIO_FLAG_DONT_CACHE;
zio->io_stage = ZIO_STAGE_VDEV_IO_SETUP - 1;
dprintf("retry #%d for %s to %s offset %llx\n",
zio->io_retries, zio_type_name[zio->io_type],
vdev_description(vd), zio->io_offset);
/*
* If this is the first retry, do it immediately.
*/
/* XXPOLICY */
if (zio->io_retries == 1) {
zio_next_stage_async(zio);
return;
}
/*
* This was not the first retry, so go through the
* longer enqueue/delay/vdev_reopen() process.
*/
mutex_enter(&tvd->vdev_io_lock);
ASSERT(zio->io_retry_next == NULL);
zio->io_retry_next = zq = tvd->vdev_io_retry;
tvd->vdev_io_retry = zio;
mutex_exit(&tvd->vdev_io_lock);
if (zq == NULL)
(void) taskq_dispatch(
tvd->vdev_spa->spa_vdev_retry_taskq,
zio_vdev_io_retry, tvd, TQ_SLEEP);
return;
}
zio_next_stage(zio);
}
void
zio_vdev_io_reissue(zio_t *zio)
{
ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
ASSERT(zio->io_error == 0);
zio->io_stage--;
}
void
zio_vdev_io_redone(zio_t *zio)
{
ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
zio->io_stage--;
}
void
zio_vdev_io_bypass(zio_t *zio)
{
ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
ASSERT(zio->io_error == 0);
zio->io_flags |= ZIO_FLAG_IO_BYPASS;
zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS - 1;
}
/*
* ==========================================================================
* Generate and verify checksums
* ==========================================================================
*/
static void
zio_checksum_generate(zio_t *zio)
{
int checksum = zio->io_checksum;
blkptr_t *bp = zio->io_bp;
ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
BP_SET_CHECKSUM(bp, checksum);
BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
zio_checksum(checksum, &bp->blk_cksum, zio->io_data, zio->io_size);
zio_next_stage(zio);
}
static void
zio_gang_checksum_generate(zio_t *zio)
{
zio_cksum_t zc;
zio_gbh_phys_t *gbh = zio->io_data;
ASSERT3U(zio->io_size, ==, SPA_GANGBLOCKSIZE);
ASSERT(DVA_GET_GANG(ZIO_GET_DVA(zio)));
zio_set_gang_verifier(zio, &gbh->zg_tail.zbt_cksum);
zio_checksum(ZIO_CHECKSUM_GANG_HEADER, &zc, zio->io_data, zio->io_size);
zio_next_stage(zio);
}
static void
zio_checksum_verify(zio_t *zio)
{
if (zio->io_bp != NULL) {
zio->io_error = zio_checksum_error(zio);
if (zio->io_error) {
dprintf("bad checksum on vdev %s\n",
vdev_description(zio->io_vd));
}
}
zio_next_stage(zio);
}
/*
* Called by RAID-Z to ensure we don't compute the checksum twice.
*/
void
zio_checksum_verified(zio_t *zio)
{
zio->io_pipeline &= ~(1U << ZIO_STAGE_CHECKSUM_VERIFY);
}
/*
* Set the external verifier for a gang block based on stuff in the bp
*/
void
zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp)
{
zcp->zc_word[0] = DVA_GET_VDEV(ZIO_GET_DVA(zio));
zcp->zc_word[1] = DVA_GET_OFFSET(ZIO_GET_DVA(zio));
zcp->zc_word[2] = zio->io_bp->blk_birth;
zcp->zc_word[3] = 0;
}
/*
* ==========================================================================
* Define the pipeline
* ==========================================================================
*/
typedef void zio_pipe_stage_t(zio_t *zio);
static void
zio_badop(zio_t *zio)
{
panic("Invalid I/O pipeline stage %u for zio %p", zio->io_stage, zio);
}
zio_pipe_stage_t *zio_pipeline[ZIO_STAGE_DONE + 2] = {
zio_badop,
zio_wait_children_ready,
zio_write_compress,
zio_checksum_generate,
zio_gang_pipeline,
zio_get_gang_header,
zio_rewrite_gang_members,
zio_free_gang_members,
zio_claim_gang_members,
zio_dva_allocate,
zio_dva_free,
zio_dva_claim,
zio_gang_checksum_generate,
zio_ready,
zio_dva_translate,
zio_vdev_io_setup,
zio_vdev_io_start,
zio_vdev_io_done,
zio_vdev_io_assess,
zio_wait_children_done,
zio_checksum_verify,
zio_read_gang_members,
zio_read_decompress,
zio_done,
zio_badop
};
/*
* Move an I/O to the next stage of the pipeline and execute that stage.
* There's no locking on io_stage because there's no legitimate way for
* multiple threads to be attempting to process the same I/O.
*/
void
zio_next_stage(zio_t *zio)
{
uint32_t pipeline = zio->io_pipeline;
ASSERT(!MUTEX_HELD(&zio->io_lock));
if (zio->io_error) {
dprintf("zio %p vdev %s offset %llx stage %d error %d\n",
zio, vdev_description(zio->io_vd),
zio->io_offset, zio->io_stage, zio->io_error);
if (((1U << zio->io_stage) & ZIO_VDEV_IO_PIPELINE) == 0)
pipeline &= ZIO_ERROR_PIPELINE_MASK;
}
while (((1U << ++zio->io_stage) & pipeline) == 0)
continue;
ASSERT(zio->io_stage <= ZIO_STAGE_DONE);
ASSERT(zio->io_stalled == 0);
zio_pipeline[zio->io_stage](zio);
}
void
zio_next_stage_async(zio_t *zio)
{
taskq_t *tq;
uint32_t pipeline = zio->io_pipeline;
ASSERT(!MUTEX_HELD(&zio->io_lock));
if (zio->io_error) {
dprintf("zio %p vdev %s offset %llx stage %d error %d\n",
zio, vdev_description(zio->io_vd),
zio->io_offset, zio->io_stage, zio->io_error);
if (((1U << zio->io_stage) & ZIO_VDEV_IO_PIPELINE) == 0)
pipeline &= ZIO_ERROR_PIPELINE_MASK;
}
while (((1U << ++zio->io_stage) & pipeline) == 0)
continue;
ASSERT(zio->io_stage <= ZIO_STAGE_DONE);
ASSERT(zio->io_stalled == 0);
/*
* For performance, we'll probably want two sets of task queues:
* per-CPU issue taskqs and per-CPU completion taskqs. The per-CPU
* part is for read performance: since we have to make a pass over
* the data to checksum it anyway, we want to do this on the same CPU
* that issued the read, because (assuming CPU scheduling affinity)
* that thread is probably still there. Getting this optimization
* right avoids performance-hostile cache-to-cache transfers.
*
* Note that having two sets of task queues is also necessary for
* correctness: if all of the issue threads get bogged down waiting
* for dependent reads (e.g. metaslab freelist) to complete, then
* there won't be any threads available to service I/O completion
* interrupts.
*/
if ((1U << zio->io_stage) & zio->io_async_stages) {
if (zio->io_stage < ZIO_STAGE_VDEV_IO_DONE)
tq = zio->io_spa->spa_zio_issue_taskq[zio->io_type];
else
tq = zio->io_spa->spa_zio_intr_taskq[zio->io_type];
(void) taskq_dispatch(tq,
(task_func_t *)zio_pipeline[zio->io_stage], zio, TQ_SLEEP);
} else {
zio_pipeline[zio->io_stage](zio);
}
}
/*
* Try to allocate an intent log block. Return 0 on success, errno on failure.
*/
int
zio_alloc_blk(spa_t *spa, int checksum, uint64_t size, blkptr_t *bp,
uint64_t txg)
{
int error;
spa_config_enter(spa, RW_READER);
BP_ZERO(bp);
error = metaslab_alloc(spa, size, BP_IDENTITY(bp), txg);
if (error == 0) {
BP_SET_CHECKSUM(bp, checksum);
BP_SET_LSIZE(bp, size);
BP_SET_PSIZE(bp, size);
BP_SET_COMPRESS(bp, ZIO_COMPRESS_OFF);
BP_SET_TYPE(bp, DMU_OT_INTENT_LOG);
BP_SET_LEVEL(bp, 0);
BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
bp->blk_birth = txg;
}
spa_config_exit(spa);
return (error);
}
/*
* Free an intent log block. We know it can't be a gang block, so there's
* nothing to do except metaslab_free() it.
*/
void
zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg)
{
ASSERT(DVA_GET_GANG(BP_IDENTITY(bp)) == 0);
dprintf_bp(bp, "txg %llu: ", txg);
spa_config_enter(spa, RW_READER);
metaslab_free(spa, BP_IDENTITY(bp), txg);
spa_config_exit(spa);
}