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mirror_zfs/zfs/lib/libzpool/zio.c

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Initial Linux ZFS GIT Repo
2008-11-20 23:01:55 +03:00
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (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 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "@(#)zio.c 1.32 08/03/20 SMI"
#include <sys/zfs_context.h>
#include <sys/fm/fs/zfs.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>
/*
* ==========================================================================
* 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" };
/* Force an allocation failure when non-zero */
uint16_t zio_zil_fail_shift = 0;
uint16_t zio_io_fail_shift = 0;
/* Enable/disable the write-retry logic */
int zio_write_retry = 1;
/* Taskq to handle reissuing of I/Os */
taskq_t *zio_taskq;
int zio_resume_threads = 4;
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 */
};
static boolean_t zio_io_should_fail(uint16_t);
/*
* ==========================================================================
* I/O kmem caches
* ==========================================================================
*/
kmem_cache_t *zio_cache;
kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
#ifdef _KERNEL
extern vmem_t *zio_alloc_arena;
#endif
/*
* Determine if we are allowed to issue the IO based on the
* pool state. If we must wait then block until we are told
* that we may continue.
*/
#define ZIO_ENTER(spa) { \
if (spa->spa_state == POOL_STATE_IO_FAILURE) { \
mutex_enter(&spa->spa_zio_lock); \
while (spa->spa_state == POOL_STATE_IO_FAILURE) \
cv_wait(&spa->spa_zio_cv, &spa->spa_zio_lock); \
mutex_exit(&spa->spa_zio_lock); \
} \
}
/*
* An allocation zio is one that either currently has the DVA allocate
* stage set or will have it later in it's lifetime.
*/
#define IO_IS_ALLOCATING(zio) \
((zio)->io_orig_pipeline & (1U << ZIO_STAGE_DVA_ALLOCATE))
void
zio_init(void)
{
size_t c;
vmem_t *data_alloc_arena = NULL;
#ifdef _KERNEL
data_alloc_arena = zio_alloc_arena;
#endif
zio_cache = kmem_cache_create("zio_cache", sizeof (zio_t), 0,
NULL, NULL, NULL, NULL, NULL, 0);
/*
* 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[36];
(void) sprintf(name, "zio_buf_%lu", (ulong_t)size);
zio_buf_cache[c] = kmem_cache_create(name, size,
align, NULL, NULL, NULL, NULL, NULL, KMC_NODEBUG);
(void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size);
zio_data_buf_cache[c] = kmem_cache_create(name, size,
align, NULL, NULL, NULL, NULL, data_alloc_arena,
KMC_NODEBUG);
}
}
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];
ASSERT(zio_data_buf_cache[c] != NULL);
if (zio_data_buf_cache[c - 1] == NULL)
zio_data_buf_cache[c - 1] = zio_data_buf_cache[c];
}
zio_taskq = taskq_create("zio_taskq", zio_resume_threads,
maxclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
zio_inject_init();
}
void
zio_fini(void)
{
size_t c;
kmem_cache_t *last_cache = NULL;
kmem_cache_t *last_data_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;
if (zio_data_buf_cache[c] != last_data_cache) {
last_data_cache = zio_data_buf_cache[c];
kmem_cache_destroy(zio_data_buf_cache[c]);
}
zio_data_buf_cache[c] = NULL;
}
taskq_destroy(zio_taskq);
kmem_cache_destroy(zio_cache);
zio_inject_fini();
}
/*
* ==========================================================================
* Allocate and free I/O buffers
* ==========================================================================
*/
/*
* Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
* crashdump if the kernel panics, so use it judiciously. Obviously, it's
* useful to inspect ZFS metadata, but if possible, we should avoid keeping
* excess / transient data in-core during a crashdump.
*/
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_PUSHPAGE));
}
/*
* Use zio_data_buf_alloc to allocate data. The data will not appear in a
* crashdump if the kernel panics. This exists so that we will limit the amount
* of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
* of kernel heap dumped to disk when the kernel panics)
*/
void *
zio_data_buf_alloc(size_t size)
{
size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
}
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);
}
void
zio_data_buf_free(void *buf, size_t size)
{
size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
kmem_cache_free(zio_data_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_cache_alloc(zio_cache, KM_SLEEP);
bzero(zio, sizeof (zio_t));
zio->io_parent = pio;
zio->io_spa = spa;
zio->io_txg = txg;
zio->io_flags = flags;
if (bp != NULL) {
zio->io_bp = bp;
zio->io_bp_copy = *bp;
zio->io_bp_orig = *bp;
}
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_timestamp = lbolt64;
mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL);
cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
zio_push_transform(zio, data, size, size);
/*
* Note on config lock:
*
* If CONFIG_HELD is set, then the caller already has the config
* lock, so we don't need it for this io.
*
* We set CONFIG_GRABBED to indicate that we have grabbed the
* config lock on behalf of this io, so it should be released
* in zio_done.
*
* Unless CONFIG_HELD is set, we will grab the config lock for
* any top-level (parent-less) io, *except* NULL top-level ios.
* The NULL top-level ios rarely have any children, so we delay
* grabbing the lock until the first child is added (but it is
* still grabbed on behalf of the top-level i/o, so additional
* children don't need to also grab it). This greatly reduces
* contention on the config lock.
*/
if (pio == NULL) {
if (type != ZIO_TYPE_NULL &&
!(flags & ZIO_FLAG_CONFIG_HELD)) {
spa_config_enter(spa, RW_READER, zio);
zio->io_flags |= ZIO_FLAG_CONFIG_GRABBED;
}
zio->io_root = zio;
} else {
zio->io_root = pio->io_root;
if (!(flags & ZIO_FLAG_NOBOOKMARK))
zio->io_logical = pio->io_logical;
mutex_enter(&pio->io_lock);
if (pio->io_parent == NULL &&
pio->io_type == ZIO_TYPE_NULL &&
!(pio->io_flags & ZIO_FLAG_CONFIG_GRABBED) &&
!(pio->io_flags & ZIO_FLAG_CONFIG_HELD)) {
pio->io_flags |= ZIO_FLAG_CONFIG_GRABBED;
spa_config_enter(spa, RW_READER, pio);
}
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;
zio->io_ndvas = pio->io_ndvas;
mutex_exit(&pio->io_lock);
}
/*
* Save off the original state incase we need to retry later.
*/
zio->io_orig_stage = zio->io_stage;
zio->io_orig_pipeline = zio->io_pipeline;
zio->io_orig_flags = zio->io_flags;
return (zio);
}
static void
zio_reset(zio_t *zio)
{
zio_clear_transform_stack(zio);
zio->io_flags = zio->io_orig_flags;
zio->io_stage = zio->io_orig_stage;
zio->io_pipeline = zio->io_orig_pipeline;
zio_push_transform(zio, zio->io_data, zio->io_size, zio->io_size);
}
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, zbookmark_t *zb)
{
zio_t *zio;
ASSERT3U(size, ==, BP_GET_LSIZE(bp));
/*
* If the user has specified that we allow I/Os to continue
* then attempt to satisfy the read.
*/
if (spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE)
ZIO_ENTER(spa);
zio = zio_create(pio, spa, bp->blk_birth, bp, data, size, done, private,
ZIO_TYPE_READ, priority, flags | ZIO_FLAG_USER,
ZIO_STAGE_OPEN, ZIO_READ_PIPELINE);
zio->io_bookmark = *zb;
zio->io_logical = zio;
/*
* 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(zio_t *pio, spa_t *spa, int checksum, int compress, int ncopies,
uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
zio_done_func_t *ready, zio_done_func_t *done, void *private, int priority,
int flags, zbookmark_t *zb)
{
zio_t *zio;
ASSERT(checksum >= ZIO_CHECKSUM_OFF &&
checksum < ZIO_CHECKSUM_FUNCTIONS);
ASSERT(compress >= ZIO_COMPRESS_OFF &&
compress < ZIO_COMPRESS_FUNCTIONS);
ZIO_ENTER(spa);
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_USER,
ZIO_STAGE_OPEN, ZIO_WRITE_PIPELINE);
zio->io_ready = ready;
zio->io_bookmark = *zb;
zio->io_logical = zio;
zio->io_checksum = checksum;
zio->io_compress = compress;
zio->io_ndvas = ncopies;
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);
} else {
/* Make sure someone doesn't change their mind on overwrites */
ASSERT(MIN(zio->io_ndvas + BP_IS_GANG(bp),
spa_max_replication(spa)) == BP_GET_NDVAS(bp));
}
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,
zbookmark_t *zb)
{
zio_t *zio;
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_USER,
ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE(bp));
zio->io_bookmark = *zb;
zio->io_checksum = checksum;
zio->io_compress = ZIO_COMPRESS_OFF;
if (pio != NULL)
ASSERT3U(zio->io_ndvas, <=, BP_GET_NDVAS(bp));
return (zio);
}
static void
zio_write_allocate_ready(zio_t *zio)
{
/* Free up the previous block */
if (!BP_IS_HOLE(&zio->io_bp_orig)) {
zio_nowait(zio_free(zio, zio->io_spa, zio->io_txg,
&zio->io_bp_orig, NULL, NULL));
}
}
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;
zio->io_ready = zio_write_allocate_ready;
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));
}
zio = zio_create(pio, spa, txg, bp, NULL, 0, done, private,
ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, ZIO_FLAG_USER,
ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE(bp));
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);
zio = zio_create(pio, spa, txg, bp, NULL, 0, done, private,
ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, 0,
ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE(bp));
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, boolean_t labels)
{
ASSERT(vd->vdev_children == 0);
ASSERT(size <= SPA_MAXBLOCKSIZE);
ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0);
ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
#ifdef ZFS_DEBUG
if (labels) {
ASSERT(offset + size <= VDEV_LABEL_START_SIZE ||
offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
}
#endif
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, boolean_t labels)
{
zio_t *zio;
blkptr_t blk;
ZIO_ENTER(vd->vdev_spa);
zio_phys_bp_init(vd, &blk, offset, size, checksum, labels);
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, boolean_t labels)
{
zio_block_tail_t *zbt;
void *wbuf;
zio_t *zio;
blkptr_t blk;
ZIO_ENTER(vd->vdev_spa);
zio_phys_bp_init(vd, &blk, offset, size, checksum, labels);
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_START - 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_execute(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;
mutex_destroy(&zio->io_lock);
cv_destroy(&zio->io_cv);
kmem_cache_free(zio_cache, zio);
return (error);
}
void
zio_nowait(zio_t *zio)
{
zio_execute(zio);
}
void
zio_interrupt(zio_t *zio)
{
(void) taskq_dispatch(zio->io_spa->spa_zio_intr_taskq[zio->io_type],
(task_func_t *)zio_execute, zio, TQ_SLEEP);
}
static int
zio_issue_async(zio_t *zio)
{
(void) taskq_dispatch(zio->io_spa->spa_zio_issue_taskq[zio->io_type],
(task_func_t *)zio_execute, zio, TQ_SLEEP);
return (ZIO_PIPELINE_STOP);
}
/*
* ==========================================================================
* I/O pipeline interlocks: parent/child dependency scoreboarding
* ==========================================================================
*/
static int
zio_wait_for_children(zio_t *zio, uint32_t stage, uint64_t *countp)
{
int rv = ZIO_PIPELINE_CONTINUE;
mutex_enter(&zio->io_lock);
ASSERT(zio->io_stalled == 0);
if (*countp != 0) {
zio->io_stalled = stage;
rv = ZIO_PIPELINE_STOP;
}
mutex_exit(&zio->io_lock);
return (rv);
}
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;
ASSERT3U(*countp, >, 0);
if (--*countp == 0 && pio->io_stalled == stage) {
pio->io_stalled = 0;
mutex_exit(&pio->io_lock);
zio_execute(pio);
} else {
mutex_exit(&pio->io_lock);
}
}
int
zio_wait_for_children_ready(zio_t *zio)
{
return (zio_wait_for_children(zio, ZIO_STAGE_WAIT_FOR_CHILDREN_READY,
&zio->io_children_notready));
}
int
zio_wait_for_children_done(zio_t *zio)
{
return (zio_wait_for_children(zio, ZIO_STAGE_WAIT_FOR_CHILDREN_DONE,
&zio->io_children_notdone));
}
static int
zio_read_init(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
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 (BP_IS_GANG(bp)) {
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;
}
if (!dmu_ot[BP_GET_TYPE(bp)].ot_metadata && BP_GET_LEVEL(bp) == 0)
zio->io_flags |= ZIO_FLAG_DONT_CACHE;
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_ready(zio_t *zio)
{
zio_t *pio = zio->io_parent;
if (zio->io_ready)
zio->io_ready(zio);
if (pio != NULL)
zio_notify_parent(zio, ZIO_STAGE_WAIT_FOR_CHILDREN_READY,
&pio->io_children_notready);
if (zio->io_bp)
zio->io_bp_copy = *zio->io_bp;
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_vdev_retry_io(zio_t *zio)
{
zio_t *pio = zio->io_parent;
/*
* Preserve the failed bp so that the io_ready() callback can
* update the accounting accordingly. The callback will also be
* responsible for freeing the previously allocated block, if one
* exists.
*/
zio->io_bp_orig = *zio->io_bp;
/*
* We must zero out the old DVA and blk_birth before reallocating
* the bp.
*/
BP_ZERO_DVAS(zio->io_bp);
zio_reset(zio);
if (pio) {
/*
* Let the parent know that we will
* re-alloc the write (=> new bp info).
*/
mutex_enter(&pio->io_lock);
pio->io_children_notready++;
/*
* If the parent I/O is still in the open stage, then
* don't bother telling it to retry since it hasn't
* progressed far enough for it to care.
*/
if (pio->io_stage > ZIO_STAGE_OPEN && IO_IS_ALLOCATING(pio))
pio->io_flags |= ZIO_FLAG_WRITE_RETRY;
ASSERT(pio->io_stage <= ZIO_STAGE_WAIT_FOR_CHILDREN_DONE);
mutex_exit(&pio->io_lock);
}
/*
* We are getting ready to process the retry request so clear
* the flag and the zio's current error status.
*/
zio->io_flags &= ~ZIO_FLAG_WRITE_RETRY;
zio->io_error = 0;
return (ZIO_PIPELINE_CONTINUE);
}
int
zio_vdev_resume_io(spa_t *spa)
{
zio_t *zio;
mutex_enter(&spa->spa_zio_lock);
/*
* Probe all of vdevs that have experienced an I/O error.
* If we are still unable to verify the integrity of the vdev
* then we prevent the resume from proceeeding.
*/
for (zio = list_head(&spa->spa_zio_list); zio != NULL;
zio = list_next(&spa->spa_zio_list, zio)) {
int error = 0;
/* We only care about I/Os that must succeed */
if (zio->io_vd == NULL || zio->io_flags & ZIO_FLAG_CANFAIL)
continue;
error = vdev_probe(zio->io_vd);
if (error) {
mutex_exit(&spa->spa_zio_lock);
return (error);
}
}
/*
* Clear the vdev stats so that I/O can flow.
*/
vdev_clear(spa, NULL, B_FALSE);
spa->spa_state = POOL_STATE_ACTIVE;
while ((zio = list_head(&spa->spa_zio_list)) != NULL) {
list_remove(&spa->spa_zio_list, zio);
zio->io_error = 0;
/*
* If we are resuming an allocating I/O then we force it
* to retry and let it resume operation where it left off.
* Otherwise, go back to the ready stage and pick up from
* there.
*/
if (zio_write_retry && IO_IS_ALLOCATING(zio)) {
zio->io_flags |= ZIO_FLAG_WRITE_RETRY;
zio->io_stage--;
} else {
zio->io_stage = ZIO_STAGE_READY;
}
(void) taskq_dispatch(zio_taskq, (task_func_t *)zio_execute,
zio, TQ_SLEEP);
}
mutex_exit(&spa->spa_zio_lock);
/*
* Wait for the taskqs to finish and recheck the pool state since
* it's possible that a resumed I/O has failed again.
*/
taskq_wait(zio_taskq);
if (spa_state(spa) == POOL_STATE_IO_FAILURE)
return (EIO);
mutex_enter(&spa->spa_zio_lock);
cv_broadcast(&spa->spa_zio_cv);
mutex_exit(&spa->spa_zio_lock);
return (0);
}
static int
zio_vdev_suspend_io(zio_t *zio)
{
spa_t *spa = zio->io_spa;
/*
* We've experienced an unrecoverable failure so
* set the pool state accordingly and queue all
* failed IOs.
*/
spa->spa_state = POOL_STATE_IO_FAILURE;
mutex_enter(&spa->spa_zio_lock);
list_insert_tail(&spa->spa_zio_list, zio);
#ifndef _KERNEL
/* Used to notify ztest that the pool has suspended */
cv_broadcast(&spa->spa_zio_cv);
#endif
mutex_exit(&spa->spa_zio_lock);
return (ZIO_PIPELINE_STOP);
}
static int
zio_assess(zio_t *zio)
{
spa_t *spa = zio->io_spa;
blkptr_t *bp = zio->io_bp;
vdev_t *vd = zio->io_vd;
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 (zio->io_ndvas != 0)
ASSERT3U(zio->io_ndvas, <=, BP_GET_NDVAS(bp));
ASSERT(BP_COUNT_GANG(bp) == 0 ||
(BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp)));
}
}
/*
* Some child I/O has indicated that a retry is necessary, so
* we set an error on the I/O and let the logic below do the
* rest.
*/
if (zio->io_flags & ZIO_FLAG_WRITE_RETRY)
zio->io_error = ERESTART;
if (vd != NULL)
vdev_stat_update(zio);
if (zio->io_error) {
/*
* If this I/O is attached to a particular vdev,
* generate an error message describing the I/O failure
* at the block level. We ignore these errors if the
* device is currently unavailable.
*/
if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd))
zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0);
if ((zio->io_error == EIO ||
!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) &&
zio->io_logical == zio) {
/*
* For root I/O requests, tell the SPA to log the error
* appropriately. Also, generate a logical data
* ereport.
*/
spa_log_error(spa, zio);
zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio,
0, 0);
}
/*
* If we are an allocating I/O then we attempt to reissue
* the I/O on another vdev unless the pool is out of space.
* We handle this condition based on the spa's failmode
* property.
*/
if (zio_write_retry && zio->io_error != ENOSPC &&
IO_IS_ALLOCATING(zio))
return (zio_vdev_retry_io(zio));
ASSERT(!(zio->io_flags & ZIO_FLAG_WRITE_RETRY));
/*
* For I/O requests that cannot fail, we carry out
* the requested behavior based on the failmode pool
* property.
*
* XXX - Need to differentiate between an ENOSPC as
* a result of vdev failures vs. a full pool.
*/
if (!(zio->io_flags & ZIO_FLAG_CANFAIL)) {
char *blkbuf;
#ifdef ZFS_DEBUG
blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_NOSLEEP);
if (blkbuf) {
sprintf_blkptr(blkbuf, BP_SPRINTF_LEN,
bp ? bp : &zio->io_bp_copy);
}
cmn_err(CE_WARN, "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,
(void *)zio, blkbuf ? blkbuf : "", zio->io_error);
#endif
if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) {
fm_panic("Pool '%s' has encountered an "
"uncorrectable I/O failure and the "
"failure mode property for this pool "
"is set to panic.", spa_name(spa));
}
cmn_err(CE_WARN, "Pool '%s' has encountered "
"an uncorrectable I/O error. "
"Manual intervention is required.", spa_name(spa));
return (zio_vdev_suspend_io(zio));
}
}
ASSERT(!(zio->io_flags & ZIO_FLAG_WRITE_RETRY));
ASSERT(zio->io_children_notready == 0);
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_done(zio_t *zio)
{
zio_t *pio = zio->io_parent;
spa_t *spa = zio->io_spa;
ASSERT(zio->io_children_notready == 0);
ASSERT(zio->io_children_notdone == 0);
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_FOR_CHILDREN_DONE,
&pio->io_children_notdone);
}
/*
* Note: this I/O is now done, and will shortly be freed, so there is no
* need to clear this (or any other) flag.
*/
if (zio->io_flags & ZIO_FLAG_CONFIG_GRABBED)
spa_config_exit(spa, zio);
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 {
mutex_destroy(&zio->io_lock);
cv_destroy(&zio->io_cv);
kmem_cache_free(zio_cache, zio);
}
return (ZIO_PIPELINE_STOP);
}
/*
* ==========================================================================
* Compression support
* ==========================================================================
*/
static int
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);
BP_SET_LSIZE(bp, lsize);
BP_SET_COMPRESS(bp, compress);
zio->io_pipeline = ZIO_REWRITE_PIPELINE(bp);
} else {
if (bp->blk_birth == zio->io_txg)
BP_ZERO(bp);
if (csize == 0) {
BP_ZERO(bp);
zio->io_pipeline = ZIO_WAIT_FOR_CHILDREN_PIPELINE;
} else {
ASSERT3U(BP_GET_NDVAS(bp), ==, 0);
BP_SET_LSIZE(bp, lsize);
BP_SET_PSIZE(bp, csize);
BP_SET_COMPRESS(bp, compress);
}
}
return (ZIO_PIPELINE_CONTINUE);
}
static int
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);
return (ZIO_PIPELINE_CONTINUE);
}
/*
* ==========================================================================
* Gang block support
* ==========================================================================
*/
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 int
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(BP_IS_GANG(bp));
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_GANG_PIPELINE));
return (zio_wait_for_children_done(zio));
}
static int
zio_read_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize, loff, lsize;
int i;
ASSERT(BP_IS_GANG(zio->io_bp));
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->io_bookmark));
}
zio_buf_free(gbh, gbufsize);
return (zio_wait_for_children_done(zio));
}
static int
zio_rewrite_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize, loff, lsize;
int i;
ASSERT(BP_IS_GANG(zio->io_bp));
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_FLAG_GANG_INHERIT, &zio->io_bookmark));
}
zio_push_transform(zio, gbh, gsize, gbufsize);
return (zio_wait_for_children_ready(zio));
}
static int
zio_free_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize;
int i;
ASSERT(BP_IS_GANG(zio->io_bp));
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);
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_claim_gang_members(zio_t *zio)
{
zio_gbh_phys_t *gbh;
uint64_t gsize, gbufsize;
int i;
ASSERT(BP_IS_GANG(zio->io_bp));
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);
return (ZIO_PIPELINE_CONTINUE);
}
static void
zio_write_allocate_gang_member_done(zio_t *zio)
{
zio_t *pio = zio->io_parent;
dva_t *cdva = zio->io_bp->blk_dva;
dva_t *pdva = pio->io_bp->blk_dva;
uint64_t asize;
int d;
ASSERT3U(pio->io_ndvas, ==, zio->io_ndvas);
ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
ASSERT3U(zio->io_ndvas, <=, BP_GET_NDVAS(zio->io_bp));
ASSERT3U(pio->io_ndvas, <=, BP_GET_NDVAS(pio->io_bp));
mutex_enter(&pio->io_lock);
for (d = 0; d < BP_GET_NDVAS(pio->io_bp); d++) {
ASSERT(DVA_GET_GANG(&pdva[d]));
asize = DVA_GET_ASIZE(&pdva[d]);
asize += DVA_GET_ASIZE(&cdva[d]);
DVA_SET_ASIZE(&pdva[d], asize);
}
mutex_exit(&pio->io_lock);
}
static int
zio_write_allocate_gang_members(zio_t *zio, metaslab_class_t *mc)
{
blkptr_t *bp = zio->io_bp;
dva_t *dva = bp->blk_dva;
spa_t *spa = zio->io_spa;
zio_gbh_phys_t *gbh;
uint64_t txg = zio->io_txg;
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 ndvas = zio->io_ndvas;
int gbh_ndvas = MIN(ndvas + 1, spa_max_replication(spa));
int error;
int i, d;
gsize = SPA_GANGBLOCKSIZE;
gbps_left = SPA_GBH_NBLKPTRS;
error = metaslab_alloc(spa, mc, gsize, bp, gbh_ndvas, txg, NULL,
B_FALSE);
if (error) {
zio->io_error = error;
return (ZIO_PIPELINE_CONTINUE);
}
for (d = 0; d < gbh_ndvas; d++)
DVA_SET_GANG(&dva[d], 1);
bp->blk_birth = 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;
ASSERT(gbps_left != 0);
maxalloc = MIN(maxalloc, resid);
while (resid <= maxalloc * gbps_left) {
error = metaslab_alloc(spa, mc, maxalloc, gbp, ndvas,
txg, bp, B_FALSE);
if (error == 0)
break;
ASSERT3U(error, ==, ENOSPC);
/* XXX - free up previous allocations? */
if (maxalloc == SPA_MINBLOCKSIZE) {
zio->io_error = error;
return (ZIO_PIPELINE_CONTINUE);
}
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 = txg;
zio_nowait(zio_rewrite(zio, spa,
zio->io_checksum, txg, gbp,
(char *)zio->io_data + loff, lsize,
zio_write_allocate_gang_member_done, NULL,
zio->io_priority,
zio->io_flags & ZIO_FLAG_GANG_INHERIT,
&zio->io_bookmark));
} else {
lsize = P2ROUNDUP(resid / gbps_left, SPA_MINBLOCKSIZE);
ASSERT(lsize != SPA_MINBLOCKSIZE);
zio_nowait(zio_write_allocate(zio, spa,
zio->io_checksum, txg, gbp,
(char *)zio->io_data + loff, lsize,
zio_write_allocate_gang_member_done, NULL,
zio->io_priority,
zio->io_flags & ZIO_FLAG_GANG_INHERIT));
}
}
ASSERT(resid == 0 && loff == zio->io_size);
zio->io_pipeline |= 1U << ZIO_STAGE_GANG_CHECKSUM_GENERATE;
zio_push_transform(zio, gbh, gsize, gsize);
/*
* As much as we'd like this to be 'ready' instead of 'done',
* updating our ASIZE doesn't happen until the io_done callback,
* so we have to wait for that to finish in order for our BP
* to be stable.
*/
return (zio_wait_for_children_done(zio));
}
/*
* ==========================================================================
* Allocate and free blocks
* ==========================================================================
*/
static int
zio_dva_allocate(zio_t *zio)
{
spa_t *spa = zio->io_spa;
metaslab_class_t *mc = spa->spa_normal_class;
blkptr_t *bp = zio->io_bp;
int error;
ASSERT(BP_IS_HOLE(bp));
ASSERT3U(BP_GET_NDVAS(bp), ==, 0);
ASSERT3U(zio->io_ndvas, >, 0);
ASSERT3U(zio->io_ndvas, <=, spa_max_replication(spa));
/*
* For testing purposes, we force I/Os to retry. We don't allow
* retries beyond the first pass since those I/Os are non-allocating
* writes.
*/
if (zio_io_fail_shift &&
spa_sync_pass(zio->io_spa) <= zio_sync_pass.zp_rewrite &&
zio_io_should_fail(zio_io_fail_shift))
zio->io_flags |= ZIO_FLAG_WRITE_RETRY;
ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
error = metaslab_alloc(spa, mc, zio->io_size, bp, zio->io_ndvas,
zio->io_txg, NULL, B_FALSE);
if (error == 0) {
bp->blk_birth = zio->io_txg;
} else if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) {
return (zio_write_allocate_gang_members(zio, mc));
} else {
zio->io_error = error;
}
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_dva_free(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
metaslab_free(zio->io_spa, bp, zio->io_txg, B_FALSE);
BP_ZERO(bp);
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_dva_claim(zio_t *zio)
{
zio->io_error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
return (ZIO_PIPELINE_CONTINUE);
}
/*
* ==========================================================================
* Read and write to physical devices
* ==========================================================================
*/
static int
zio_vdev_io_start(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_t *tvd = vd ? vd->vdev_top : NULL;
blkptr_t *bp = zio->io_bp;
uint64_t align;
spa_t *spa = zio->io_spa;
/*
* If the pool is already in a failure state then just suspend
* this IO until the problem is resolved. We will reissue them
* at that time.
*/
if (spa_state(spa) == POOL_STATE_IO_FAILURE &&
zio->io_type == ZIO_TYPE_WRITE)
return (zio_vdev_suspend_io(zio));
/*
* The mirror_ops handle multiple DVAs in a single BP
*/
if (vd == NULL)
return (vdev_mirror_ops.vdev_op_io_start(zio));
align = 1ULL << tvd->vdev_ashift;
if (zio->io_retries == 0 && vd == tvd)
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;
}
if (P2PHASE(zio->io_size, align) != 0) {
uint64_t asize = P2ROUNDUP(zio->io_size, align);
char *abuf = zio_buf_alloc(asize);
ASSERT(vd == tvd);
if (zio->io_type == ZIO_TYPE_WRITE) {
bcopy(zio->io_data, abuf, zio->io_size);
bzero(abuf + zio->io_size, asize - zio->io_size);
}
zio_push_transform(zio, abuf, asize, asize);
ASSERT(!(zio->io_flags & ZIO_FLAG_SUBBLOCK));
zio->io_flags |= ZIO_FLAG_SUBBLOCK;
}
ASSERT(P2PHASE(zio->io_offset, align) == 0);
ASSERT(P2PHASE(zio->io_size, align) == 0);
ASSERT(bp == NULL ||
P2ROUNDUP(ZIO_GET_IOSIZE(zio), align) == zio->io_size);
ASSERT(zio->io_type != ZIO_TYPE_WRITE || (spa_mode & FWRITE));
return (vd->vdev_ops->vdev_op_io_start(zio));
}
static int
zio_vdev_io_done(zio_t *zio)
{
if (zio->io_vd == NULL)
return (vdev_mirror_ops.vdev_op_io_done(zio));
return (zio->io_vd->vdev_ops->vdev_op_io_done(zio));
}
/* XXPOLICY */
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 != vd->vdev_top)
return (B_FALSE);
if (zio->io_flags & ZIO_FLAG_DONT_RETRY)
return (B_FALSE);
if (zio->io_retries > 0)
return (B_FALSE);
return (B_TRUE);
}
static int
zio_vdev_io_assess(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_t *tvd = vd ? vd->vdev_top : NULL;
ASSERT(zio->io_vsd == NULL);
if (zio->io_flags & ZIO_FLAG_SUBBLOCK) {
void *abuf;
uint64_t asize;
ASSERT(vd == tvd);
zio_pop_transform(zio, &abuf, &asize, &asize);
if (zio->io_type == ZIO_TYPE_READ)
bcopy(abuf, zio->io_data, zio->io_size);
zio_buf_free(abuf, asize);
zio->io_flags &= ~ZIO_FLAG_SUBBLOCK;
}
if (zio_injection_enabled && !zio->io_error)
zio->io_error = zio_handle_fault_injection(zio, EIO);
/*
* If the I/O failed, determine whether we should attempt to retry it.
*/
/* XXPOLICY */
if (zio_should_retry(zio)) {
ASSERT(tvd == vd);
zio->io_retries++;
zio->io_error = 0;
zio->io_flags &= ZIO_FLAG_RETRY_INHERIT;
/* XXPOLICY */
zio->io_flags &= ~ZIO_FLAG_FAILFAST;
zio->io_flags |= ZIO_FLAG_DONT_CACHE;
zio->io_stage = ZIO_STAGE_VDEV_IO_START - 1;
return (ZIO_PIPELINE_CONTINUE);
}
return (ZIO_PIPELINE_CONTINUE);
}
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 int
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);
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_gang_checksum_generate(zio_t *zio)
{
zio_cksum_t zc;
zio_gbh_phys_t *gbh = zio->io_data;
ASSERT(BP_IS_GANG(zio->io_bp));
ASSERT3U(zio->io_size, ==, SPA_GANGBLOCKSIZE);
zio_set_gang_verifier(zio, &gbh->zg_tail.zbt_cksum);
zio_checksum(ZIO_CHECKSUM_GANG_HEADER, &zc, zio->io_data, zio->io_size);
return (ZIO_PIPELINE_CONTINUE);
}
static int
zio_checksum_verify(zio_t *zio)
{
if (zio->io_bp != NULL) {
zio->io_error = zio_checksum_error(zio);
if (zio->io_error && !(zio->io_flags & ZIO_FLAG_SPECULATIVE))
zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM,
zio->io_spa, zio->io_vd, zio, 0, 0);
}
return (ZIO_PIPELINE_CONTINUE);
}
/*
* 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)
{
blkptr_t *bp = zio->io_bp;
zcp->zc_word[0] = DVA_GET_VDEV(BP_IDENTITY(bp));
zcp->zc_word[1] = DVA_GET_OFFSET(BP_IDENTITY(bp));
zcp->zc_word[2] = bp->blk_birth;
zcp->zc_word[3] = 0;
}
/*
* ==========================================================================
* Define the pipeline
* ==========================================================================
*/
typedef int zio_pipe_stage_t(zio_t *zio);
zio_pipe_stage_t *zio_pipeline[ZIO_STAGE_DONE + 2] = {
NULL,
zio_wait_for_children_ready,
zio_read_init,
zio_issue_async,
zio_write_compress,
zio_checksum_generate,
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_vdev_io_start,
zio_vdev_io_done,
zio_vdev_io_assess,
zio_wait_for_children_done,
zio_checksum_verify,
zio_read_gang_members,
zio_read_decompress,
zio_assess,
zio_done,
NULL
};
/*
* Execute the I/O pipeline until one of the following occurs:
* (1) the I/O completes; (2) the pipeline stalls waiting for
* dependent child I/Os; (3) the I/O issues, so we're waiting
* for an I/O completion interrupt; (4) the I/O is delegated by
* vdev-level caching or aggregation; (5) the I/O is deferred
* due to vdev-level queueing; (6) the I/O is handed off to
* another thread. In all cases, the pipeline stops whenever
* there's no CPU work; it never burns a thread in cv_wait().
*
* 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_execute(zio_t *zio)
{
while (zio->io_stage < ZIO_STAGE_DONE) {
uint32_t pipeline = zio->io_pipeline;
int rv;
ASSERT(!MUTEX_HELD(&zio->io_lock));
/*
* If an error occurred outside the vdev stack,
* just execute the interlock stages to clean up.
*/
if (zio->io_error &&
((1U << zio->io_stage) & ZIO_VDEV_IO_STAGES) == 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);
rv = zio_pipeline[zio->io_stage](zio);
if (rv == ZIO_PIPELINE_STOP)
return;
ASSERT(rv == ZIO_PIPELINE_CONTINUE);
}
}
static boolean_t
zio_io_should_fail(uint16_t range)
{
static uint16_t allocs = 0;
return (P2PHASE(allocs++, 1U<<range) == 0);
}
/*
* Try to allocate an intent log block. Return 0 on success, errno on failure.
*/
int
zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp, blkptr_t *old_bp,
uint64_t txg)
{
int error;
spa_config_enter(spa, RW_READER, FTAG);
if (zio_zil_fail_shift && zio_io_should_fail(zio_zil_fail_shift)) {
spa_config_exit(spa, FTAG);
return (ENOSPC);
}
/*
* We were passed the previous log block's DVA in bp->blk_dva[0].
* We use that as a hint for which vdev to allocate from next.
*/
error = metaslab_alloc(spa, spa->spa_log_class, size,
new_bp, 1, txg, old_bp, B_TRUE);
if (error)
error = metaslab_alloc(spa, spa->spa_normal_class, size,
new_bp, 1, txg, old_bp, B_TRUE);
if (error == 0) {
BP_SET_LSIZE(new_bp, size);
BP_SET_PSIZE(new_bp, size);
BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
BP_SET_CHECKSUM(new_bp, ZIO_CHECKSUM_ZILOG);
BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
BP_SET_LEVEL(new_bp, 0);
BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
new_bp->blk_birth = txg;
}
spa_config_exit(spa, FTAG);
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(!BP_IS_GANG(bp));
spa_config_enter(spa, RW_READER, FTAG);
metaslab_free(spa, bp, txg, B_FALSE);
spa_config_exit(spa, FTAG);
}
/*
* start an async flush of the write cache for this vdev
*/
void
zio_flush(zio_t *zio, vdev_t *vd)
{
zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
NULL, NULL, ZIO_PRIORITY_NOW,
ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY));
}
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