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zfs-builds-mm/zfs-0.8.5/module/zfs/zio.c
root f2f36bfe93 add_zfs_0.8.5
2020-10-22 13:48:46 +02:00

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/*
* 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011, 2019 by Delphix. All rights reserved.
* Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2017, Intel Corporation.
*/
#include <sys/sysmacros.h>
#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/vdev_trim.h>
#include <sys/zio_impl.h>
#include <sys/zio_compress.h>
#include <sys/zio_checksum.h>
#include <sys/dmu_objset.h>
#include <sys/arc.h>
#include <sys/ddt.h>
#include <sys/blkptr.h>
#include <sys/zfeature.h>
#include <sys/dsl_scan.h>
#include <sys/metaslab_impl.h>
#include <sys/time.h>
#include <sys/trace_zio.h>
#include <sys/abd.h>
#include <sys/dsl_crypt.h>
#include <sys/cityhash.h>
/*
* ==========================================================================
* I/O type descriptions
* ==========================================================================
*/
const char *zio_type_name[ZIO_TYPES] = {
/*
* Note: Linux kernel thread name length is limited
* so these names will differ from upstream open zfs.
*/
"z_null", "z_rd", "z_wr", "z_fr", "z_cl", "z_ioctl", "z_trim"
};
int zio_dva_throttle_enabled = B_TRUE;
int zio_deadman_log_all = B_FALSE;
/*
* ==========================================================================
* I/O kmem caches
* ==========================================================================
*/
kmem_cache_t *zio_cache;
kmem_cache_t *zio_link_cache;
kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
#if defined(ZFS_DEBUG) && !defined(_KERNEL)
uint64_t zio_buf_cache_allocs[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
#endif
/* Mark IOs as "slow" if they take longer than 30 seconds */
int zio_slow_io_ms = (30 * MILLISEC);
#define BP_SPANB(indblkshift, level) \
(((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT)))
#define COMPARE_META_LEVEL 0x80000000ul
/*
* The following actions directly effect the spa's sync-to-convergence logic.
* The values below define the sync pass when we start performing the action.
* Care should be taken when changing these values as they directly impact
* spa_sync() performance. Tuning these values may introduce subtle performance
* pathologies and should only be done in the context of performance analysis.
* These tunables will eventually be removed and replaced with #defines once
* enough analysis has been done to determine optimal values.
*
* The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that
* regular blocks are not deferred.
*
* Starting in sync pass 8 (zfs_sync_pass_dont_compress), we disable
* compression (including of metadata). In practice, we don't have this
* many sync passes, so this has no effect.
*
* The original intent was that disabling compression would help the sync
* passes to converge. However, in practice disabling compression increases
* the average number of sync passes, because when we turn compression off, a
* lot of block's size will change and thus we have to re-allocate (not
* overwrite) them. It also increases the number of 128KB allocations (e.g.
* for indirect blocks and spacemaps) because these will not be compressed.
* The 128K allocations are especially detrimental to performance on highly
* fragmented systems, which may have very few free segments of this size,
* and may need to load new metaslabs to satisfy 128K allocations.
*/
int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */
int zfs_sync_pass_dont_compress = 8; /* don't compress starting in this pass */
int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */
/*
* An allocating zio is one that either currently has the DVA allocate
* stage set or will have it later in its lifetime.
*/
#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
/*
* Enable smaller cores by excluding metadata
* allocations as well.
*/
int zio_exclude_metadata = 0;
int zio_requeue_io_start_cut_in_line = 1;
#ifdef ZFS_DEBUG
int zio_buf_debug_limit = 16384;
#else
int zio_buf_debug_limit = 0;
#endif
static inline void __zio_execute(zio_t *zio);
static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t);
void
zio_init(void)
{
size_t c;
vmem_t *data_alloc_arena = NULL;
zio_cache = kmem_cache_create("zio_cache",
sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
zio_link_cache = kmem_cache_create("zio_link_cache",
sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
/*
* For small buffers, we want a cache for each multiple of
* SPA_MINBLOCKSIZE. For larger buffers, we want a cache
* for each quarter-power of 2.
*/
for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
size_t p2 = size;
size_t align = 0;
size_t data_cflags, cflags;
data_cflags = KMC_NODEBUG;
cflags = (zio_exclude_metadata || size > zio_buf_debug_limit) ?
KMC_NODEBUG : 0;
#if defined(_ILP32) && defined(_KERNEL)
/*
* Cache size limited to 1M on 32-bit platforms until ARC
* buffers no longer require virtual address space.
*/
if (size > zfs_max_recordsize)
break;
#endif
while (!ISP2(p2))
p2 &= p2 - 1;
#ifndef _KERNEL
/*
* If we are using watchpoints, put each buffer on its own page,
* to eliminate the performance overhead of trapping to the
* kernel when modifying a non-watched buffer that shares the
* page with a watched buffer.
*/
if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE))
continue;
/*
* Here's the problem - on 4K native devices in userland on
* Linux using O_DIRECT, buffers must be 4K aligned or I/O
* will fail with EINVAL, causing zdb (and others) to coredump.
* Since userland probably doesn't need optimized buffer caches,
* we just force 4K alignment on everything.
*/
align = 8 * SPA_MINBLOCKSIZE;
#else
if (size < PAGESIZE) {
align = SPA_MINBLOCKSIZE;
} else if (IS_P2ALIGNED(size, p2 >> 2)) {
align = PAGESIZE;
}
#endif
if (align != 0) {
char name[36];
(void) snprintf(name, sizeof (name), "zio_buf_%lu",
(ulong_t)size);
zio_buf_cache[c] = kmem_cache_create(name, size,
align, NULL, NULL, NULL, NULL, NULL, cflags);
(void) snprintf(name, sizeof (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, data_cflags);
}
}
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_inject_init();
lz4_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++) {
#ifdef _ILP32
/*
* Cache size limited to 1M on 32-bit platforms until ARC
* buffers no longer require virtual address space.
*/
if (((c + 1) << SPA_MINBLOCKSHIFT) > zfs_max_recordsize)
break;
#endif
#if defined(ZFS_DEBUG) && !defined(_KERNEL)
if (zio_buf_cache_allocs[c] != zio_buf_cache_frees[c])
(void) printf("zio_fini: [%d] %llu != %llu\n",
(int)((c + 1) << SPA_MINBLOCKSHIFT),
(long long unsigned)zio_buf_cache_allocs[c],
(long long unsigned)zio_buf_cache_frees[c]);
#endif
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;
}
kmem_cache_destroy(zio_link_cache);
kmem_cache_destroy(zio_cache);
zio_inject_fini();
lz4_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;
VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
#if defined(ZFS_DEBUG) && !defined(_KERNEL)
atomic_add_64(&zio_buf_cache_allocs[c], 1);
#endif
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;
VERIFY3U(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;
VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
#if defined(ZFS_DEBUG) && !defined(_KERNEL)
atomic_add_64(&zio_buf_cache_frees[c], 1);
#endif
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;
VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
kmem_cache_free(zio_data_buf_cache[c], buf);
}
static void
zio_abd_free(void *abd, size_t size)
{
abd_free((abd_t *)abd);
}
/*
* ==========================================================================
* Push and pop I/O transform buffers
* ==========================================================================
*/
void
zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize,
zio_transform_func_t *transform)
{
zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
zt->zt_orig_abd = zio->io_abd;
zt->zt_orig_size = zio->io_size;
zt->zt_bufsize = bufsize;
zt->zt_transform = transform;
zt->zt_next = zio->io_transform_stack;
zio->io_transform_stack = zt;
zio->io_abd = data;
zio->io_size = size;
}
void
zio_pop_transforms(zio_t *zio)
{
zio_transform_t *zt;
while ((zt = zio->io_transform_stack) != NULL) {
if (zt->zt_transform != NULL)
zt->zt_transform(zio,
zt->zt_orig_abd, zt->zt_orig_size);
if (zt->zt_bufsize != 0)
abd_free(zio->io_abd);
zio->io_abd = zt->zt_orig_abd;
zio->io_size = zt->zt_orig_size;
zio->io_transform_stack = zt->zt_next;
kmem_free(zt, sizeof (zio_transform_t));
}
}
/*
* ==========================================================================
* I/O transform callbacks for subblocks, decompression, and decryption
* ==========================================================================
*/
static void
zio_subblock(zio_t *zio, abd_t *data, uint64_t size)
{
ASSERT(zio->io_size > size);
if (zio->io_type == ZIO_TYPE_READ)
abd_copy(data, zio->io_abd, size);
}
static void
zio_decompress(zio_t *zio, abd_t *data, uint64_t size)
{
if (zio->io_error == 0) {
void *tmp = abd_borrow_buf(data, size);
int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
zio->io_abd, tmp, zio->io_size, size);
abd_return_buf_copy(data, tmp, size);
if (zio_injection_enabled && ret == 0)
ret = zio_handle_fault_injection(zio, EINVAL);
if (ret != 0)
zio->io_error = SET_ERROR(EIO);
}
}
static void
zio_decrypt(zio_t *zio, abd_t *data, uint64_t size)
{
int ret;
void *tmp;
blkptr_t *bp = zio->io_bp;
spa_t *spa = zio->io_spa;
uint64_t dsobj = zio->io_bookmark.zb_objset;
uint64_t lsize = BP_GET_LSIZE(bp);
dmu_object_type_t ot = BP_GET_TYPE(bp);
uint8_t salt[ZIO_DATA_SALT_LEN];
uint8_t iv[ZIO_DATA_IV_LEN];
uint8_t mac[ZIO_DATA_MAC_LEN];
boolean_t no_crypt = B_FALSE;
ASSERT(BP_USES_CRYPT(bp));
ASSERT3U(size, !=, 0);
if (zio->io_error != 0)
return;
/*
* Verify the cksum of MACs stored in an indirect bp. It will always
* be possible to verify this since it does not require an encryption
* key.
*/
if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) {
zio_crypt_decode_mac_bp(bp, mac);
if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) {
/*
* We haven't decompressed the data yet, but
* zio_crypt_do_indirect_mac_checksum() requires
* decompressed data to be able to parse out the MACs
* from the indirect block. We decompress it now and
* throw away the result after we are finished.
*/
tmp = zio_buf_alloc(lsize);
ret = zio_decompress_data(BP_GET_COMPRESS(bp),
zio->io_abd, tmp, zio->io_size, lsize);
if (ret != 0) {
ret = SET_ERROR(EIO);
goto error;
}
ret = zio_crypt_do_indirect_mac_checksum(B_FALSE,
tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac);
zio_buf_free(tmp, lsize);
} else {
ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE,
zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac);
}
abd_copy(data, zio->io_abd, size);
if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) {
ret = zio_handle_decrypt_injection(spa,
&zio->io_bookmark, ot, ECKSUM);
}
if (ret != 0)
goto error;
return;
}
/*
* If this is an authenticated block, just check the MAC. It would be
* nice to separate this out into its own flag, but for the moment
* enum zio_flag is out of bits.
*/
if (BP_IS_AUTHENTICATED(bp)) {
if (ot == DMU_OT_OBJSET) {
ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa,
dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp));
} else {
zio_crypt_decode_mac_bp(bp, mac);
ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj,
zio->io_abd, size, mac);
if (zio_injection_enabled && ret == 0) {
ret = zio_handle_decrypt_injection(spa,
&zio->io_bookmark, ot, ECKSUM);
}
}
abd_copy(data, zio->io_abd, size);
if (ret != 0)
goto error;
return;
}
zio_crypt_decode_params_bp(bp, salt, iv);
if (ot == DMU_OT_INTENT_LOG) {
tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t));
zio_crypt_decode_mac_zil(tmp, mac);
abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t));
} else {
zio_crypt_decode_mac_bp(bp, mac);
}
ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp),
BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data,
zio->io_abd, &no_crypt);
if (no_crypt)
abd_copy(data, zio->io_abd, size);
if (ret != 0)
goto error;
return;
error:
/* assert that the key was found unless this was speculative */
ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE));
/*
* If there was a decryption / authentication error return EIO as
* the io_error. If this was not a speculative zio, create an ereport.
*/
if (ret == ECKSUM) {
zio->io_error = SET_ERROR(EIO);
if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) {
spa_log_error(spa, &zio->io_bookmark);
zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION,
spa, NULL, &zio->io_bookmark, zio, 0, 0);
}
} else {
zio->io_error = ret;
}
}
/*
* ==========================================================================
* I/O parent/child relationships and pipeline interlocks
* ==========================================================================
*/
zio_t *
zio_walk_parents(zio_t *cio, zio_link_t **zl)
{
list_t *pl = &cio->io_parent_list;
*zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl);
if (*zl == NULL)
return (NULL);
ASSERT((*zl)->zl_child == cio);
return ((*zl)->zl_parent);
}
zio_t *
zio_walk_children(zio_t *pio, zio_link_t **zl)
{
list_t *cl = &pio->io_child_list;
ASSERT(MUTEX_HELD(&pio->io_lock));
*zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl);
if (*zl == NULL)
return (NULL);
ASSERT((*zl)->zl_parent == pio);
return ((*zl)->zl_child);
}
zio_t *
zio_unique_parent(zio_t *cio)
{
zio_link_t *zl = NULL;
zio_t *pio = zio_walk_parents(cio, &zl);
VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL);
return (pio);
}
void
zio_add_child(zio_t *pio, zio_t *cio)
{
zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
/*
* Logical I/Os can have logical, gang, or vdev children.
* Gang I/Os can have gang or vdev children.
* Vdev I/Os can only have vdev children.
* The following ASSERT captures all of these constraints.
*/
ASSERT3S(cio->io_child_type, <=, pio->io_child_type);
zl->zl_parent = pio;
zl->zl_child = cio;
mutex_enter(&pio->io_lock);
mutex_enter(&cio->io_lock);
ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
for (int w = 0; w < ZIO_WAIT_TYPES; w++)
pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
list_insert_head(&pio->io_child_list, zl);
list_insert_head(&cio->io_parent_list, zl);
pio->io_child_count++;
cio->io_parent_count++;
mutex_exit(&cio->io_lock);
mutex_exit(&pio->io_lock);
}
static void
zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
{
ASSERT(zl->zl_parent == pio);
ASSERT(zl->zl_child == cio);
mutex_enter(&pio->io_lock);
mutex_enter(&cio->io_lock);
list_remove(&pio->io_child_list, zl);
list_remove(&cio->io_parent_list, zl);
pio->io_child_count--;
cio->io_parent_count--;
mutex_exit(&cio->io_lock);
mutex_exit(&pio->io_lock);
kmem_cache_free(zio_link_cache, zl);
}
static boolean_t
zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
{
boolean_t waiting = B_FALSE;
mutex_enter(&zio->io_lock);
ASSERT(zio->io_stall == NULL);
for (int c = 0; c < ZIO_CHILD_TYPES; c++) {
if (!(ZIO_CHILD_BIT_IS_SET(childbits, c)))
continue;
uint64_t *countp = &zio->io_children[c][wait];
if (*countp != 0) {
zio->io_stage >>= 1;
ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN);
zio->io_stall = countp;
waiting = B_TRUE;
break;
}
}
mutex_exit(&zio->io_lock);
return (waiting);
}
__attribute__((always_inline))
static inline void
zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait,
zio_t **next_to_executep)
{
uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
int *errorp = &pio->io_child_error[zio->io_child_type];
mutex_enter(&pio->io_lock);
if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
*errorp = zio_worst_error(*errorp, zio->io_error);
pio->io_reexecute |= zio->io_reexecute;
ASSERT3U(*countp, >, 0);
(*countp)--;
if (*countp == 0 && pio->io_stall == countp) {
zio_taskq_type_t type =
pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE :
ZIO_TASKQ_INTERRUPT;
pio->io_stall = NULL;
mutex_exit(&pio->io_lock);
/*
* If we can tell the caller to execute this parent next, do
* so. Otherwise dispatch the parent zio as its own task.
*
* Having the caller execute the parent when possible reduces
* locking on the zio taskq's, reduces context switch
* overhead, and has no recursion penalty. Note that one
* read from disk typically causes at least 3 zio's: a
* zio_null(), the logical zio_read(), and then a physical
* zio. When the physical ZIO completes, we are able to call
* zio_done() on all 3 of these zio's from one invocation of
* zio_execute() by returning the parent back to
* zio_execute(). Since the parent isn't executed until this
* thread returns back to zio_execute(), the caller should do
* so promptly.
*
* In other cases, dispatching the parent prevents
* overflowing the stack when we have deeply nested
* parent-child relationships, as we do with the "mega zio"
* of writes for spa_sync(), and the chain of ZIL blocks.
*/
if (next_to_executep != NULL && *next_to_executep == NULL) {
*next_to_executep = pio;
} else {
zio_taskq_dispatch(pio, type, B_FALSE);
}
} else {
mutex_exit(&pio->io_lock);
}
}
static void
zio_inherit_child_errors(zio_t *zio, enum zio_child c)
{
if (zio->io_child_error[c] != 0 && zio->io_error == 0)
zio->io_error = zio->io_child_error[c];
}
int
zio_bookmark_compare(const void *x1, const void *x2)
{
const zio_t *z1 = x1;
const zio_t *z2 = x2;
if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset)
return (-1);
if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset)
return (1);
if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object)
return (-1);
if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object)
return (1);
if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level)
return (-1);
if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level)
return (1);
if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid)
return (-1);
if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid)
return (1);
if (z1 < z2)
return (-1);
if (z1 > z2)
return (1);
return (0);
}
/*
* ==========================================================================
* Create the various types of I/O (read, write, free, etc)
* ==========================================================================
*/
static zio_t *
zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done,
void *private, zio_type_t type, zio_priority_t priority,
enum zio_flag flags, vdev_t *vd, uint64_t offset,
const zbookmark_phys_t *zb, enum zio_stage stage,
enum zio_stage pipeline)
{
zio_t *zio;
IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE);
ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0);
ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
ASSERT(vd || stage == ZIO_STAGE_OPEN);
IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0);
zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
bzero(zio, sizeof (zio_t));
mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL);
cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
list_create(&zio->io_parent_list, sizeof (zio_link_t),
offsetof(zio_link_t, zl_parent_node));
list_create(&zio->io_child_list, sizeof (zio_link_t),
offsetof(zio_link_t, zl_child_node));
metaslab_trace_init(&zio->io_alloc_list);
if (vd != NULL)
zio->io_child_type = ZIO_CHILD_VDEV;
else if (flags & ZIO_FLAG_GANG_CHILD)
zio->io_child_type = ZIO_CHILD_GANG;
else if (flags & ZIO_FLAG_DDT_CHILD)
zio->io_child_type = ZIO_CHILD_DDT;
else
zio->io_child_type = ZIO_CHILD_LOGICAL;
if (bp != NULL) {
zio->io_bp = (blkptr_t *)bp;
zio->io_bp_copy = *bp;
zio->io_bp_orig = *bp;
if (type != ZIO_TYPE_WRITE ||
zio->io_child_type == ZIO_CHILD_DDT)
zio->io_bp = &zio->io_bp_copy; /* so caller can free */
if (zio->io_child_type == ZIO_CHILD_LOGICAL)
zio->io_logical = zio;
if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
pipeline |= ZIO_GANG_STAGES;
}
zio->io_spa = spa;
zio->io_txg = txg;
zio->io_done = done;
zio->io_private = private;
zio->io_type = type;
zio->io_priority = priority;
zio->io_vd = vd;
zio->io_offset = offset;
zio->io_orig_abd = zio->io_abd = data;
zio->io_orig_size = zio->io_size = psize;
zio->io_lsize = lsize;
zio->io_orig_flags = zio->io_flags = flags;
zio->io_orig_stage = zio->io_stage = stage;
zio->io_orig_pipeline = zio->io_pipeline = pipeline;
zio->io_pipeline_trace = ZIO_STAGE_OPEN;
zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
if (zb != NULL)
zio->io_bookmark = *zb;
if (pio != NULL) {
if (zio->io_metaslab_class == NULL)
zio->io_metaslab_class = pio->io_metaslab_class;
if (zio->io_logical == NULL)
zio->io_logical = pio->io_logical;
if (zio->io_child_type == ZIO_CHILD_GANG)
zio->io_gang_leader = pio->io_gang_leader;
zio_add_child(pio, zio);
}
taskq_init_ent(&zio->io_tqent);
return (zio);
}
static void
zio_destroy(zio_t *zio)
{
metaslab_trace_fini(&zio->io_alloc_list);
list_destroy(&zio->io_parent_list);
list_destroy(&zio->io_child_list);
mutex_destroy(&zio->io_lock);
cv_destroy(&zio->io_cv);
kmem_cache_free(zio_cache, zio);
}
zio_t *
zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
void *private, enum zio_flag flags)
{
zio_t *zio;
zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
return (zio);
}
zio_t *
zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
{
return (zio_null(NULL, spa, NULL, done, private, flags));
}
static void
zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held)
{
if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) {
zfs_panic_recover("blkptr at %p has invalid TYPE %llu",
bp, (longlong_t)BP_GET_TYPE(bp));
}
if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS ||
BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) {
zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu",
bp, (longlong_t)BP_GET_CHECKSUM(bp));
}
if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS ||
BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) {
zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu",
bp, (longlong_t)BP_GET_COMPRESS(bp));
}
if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) {
zfs_panic_recover("blkptr at %p has invalid LSIZE %llu",
bp, (longlong_t)BP_GET_LSIZE(bp));
}
if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) {
zfs_panic_recover("blkptr at %p has invalid PSIZE %llu",
bp, (longlong_t)BP_GET_PSIZE(bp));
}
if (BP_IS_EMBEDDED(bp)) {
if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) {
zfs_panic_recover("blkptr at %p has invalid ETYPE %llu",
bp, (longlong_t)BPE_GET_ETYPE(bp));
}
}
/*
* Do not verify individual DVAs if the config is not trusted. This
* will be done once the zio is executed in vdev_mirror_map_alloc.
*/
if (!spa->spa_trust_config)
return;
if (!config_held)
spa_config_enter(spa, SCL_VDEV, bp, RW_READER);
else
ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER));
/*
* Pool-specific checks.
*
* Note: it would be nice to verify that the blk_birth and
* BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze()
* allows the birth time of log blocks (and dmu_sync()-ed blocks
* that are in the log) to be arbitrarily large.
*/
for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]);
if (vdevid >= spa->spa_root_vdev->vdev_children) {
zfs_panic_recover("blkptr at %p DVA %u has invalid "
"VDEV %llu",
bp, i, (longlong_t)vdevid);
continue;
}
vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
if (vd == NULL) {
zfs_panic_recover("blkptr at %p DVA %u has invalid "
"VDEV %llu",
bp, i, (longlong_t)vdevid);
continue;
}
if (vd->vdev_ops == &vdev_hole_ops) {
zfs_panic_recover("blkptr at %p DVA %u has hole "
"VDEV %llu",
bp, i, (longlong_t)vdevid);
continue;
}
if (vd->vdev_ops == &vdev_missing_ops) {
/*
* "missing" vdevs are valid during import, but we
* don't have their detailed info (e.g. asize), so
* we can't perform any more checks on them.
*/
continue;
}
uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]);
if (BP_IS_GANG(bp))
asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
if (offset + asize > vd->vdev_asize) {
zfs_panic_recover("blkptr at %p DVA %u has invalid "
"OFFSET %llu",
bp, i, (longlong_t)offset);
}
}
if (!config_held)
spa_config_exit(spa, SCL_VDEV, bp);
}
boolean_t
zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp)
{
uint64_t vdevid = DVA_GET_VDEV(dva);
if (vdevid >= spa->spa_root_vdev->vdev_children)
return (B_FALSE);
vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
if (vd == NULL)
return (B_FALSE);
if (vd->vdev_ops == &vdev_hole_ops)
return (B_FALSE);
if (vd->vdev_ops == &vdev_missing_ops) {
return (B_FALSE);
}
uint64_t offset = DVA_GET_OFFSET(dva);
uint64_t asize = DVA_GET_ASIZE(dva);
if (BP_IS_GANG(bp))
asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
if (offset + asize > vd->vdev_asize)
return (B_FALSE);
return (B_TRUE);
}
zio_t *
zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
abd_t *data, uint64_t size, zio_done_func_t *done, void *private,
zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb)
{
zio_t *zio;
zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER);
zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
data, size, size, done, private,
ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
return (zio);
}
zio_t *
zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp,
zio_done_func_t *ready, zio_done_func_t *children_ready,
zio_done_func_t *physdone, zio_done_func_t *done,
void *private, zio_priority_t priority, enum zio_flag flags,
const zbookmark_phys_t *zb)
{
zio_t *zio;
ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
zp->zp_compress >= ZIO_COMPRESS_OFF &&
zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
DMU_OT_IS_VALID(zp->zp_type) &&
zp->zp_level < 32 &&
zp->zp_copies > 0 &&
zp->zp_copies <= spa_max_replication(spa));
zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private,
ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
zio->io_ready = ready;
zio->io_children_ready = children_ready;
zio->io_physdone = physdone;
zio->io_prop = *zp;
/*
* Data can be NULL if we are going to call zio_write_override() to
* provide the already-allocated BP. But we may need the data to
* verify a dedup hit (if requested). In this case, don't try to
* dedup (just take the already-allocated BP verbatim). Encrypted
* dedup blocks need data as well so we also disable dedup in this
* case.
*/
if (data == NULL &&
(zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) {
zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE;
}
return (zio);
}
zio_t *
zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data,
uint64_t size, zio_done_func_t *done, void *private,
zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb)
{
zio_t *zio;
zio = zio_create(pio, spa, txg, bp, data, size, size, done, private,
ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb,
ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
return (zio);
}
void
zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
{
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
/*
* We must reset the io_prop to match the values that existed
* when the bp was first written by dmu_sync() keeping in mind
* that nopwrite and dedup are mutually exclusive.
*/
zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
zio->io_prop.zp_nopwrite = nopwrite;
zio->io_prop.zp_copies = copies;
zio->io_bp_override = bp;
}
void
zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
{
zfs_blkptr_verify(spa, bp, B_FALSE);
/*
* The check for EMBEDDED is a performance optimization. We
* process the free here (by ignoring it) rather than
* putting it on the list and then processing it in zio_free_sync().
*/
if (BP_IS_EMBEDDED(bp))
return;
metaslab_check_free(spa, bp);
/*
* Frees that are for the currently-syncing txg, are not going to be
* deferred, and which will not need to do a read (i.e. not GANG or
* DEDUP), can be processed immediately. Otherwise, put them on the
* in-memory list for later processing.
*/
if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) ||
txg != spa->spa_syncing_txg ||
spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) {
bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
} else {
VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0)));
}
}
zio_t *
zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
enum zio_flag flags)
{
zio_t *zio;
enum zio_stage stage = ZIO_FREE_PIPELINE;
ASSERT(!BP_IS_HOLE(bp));
ASSERT(spa_syncing_txg(spa) == txg);
ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free);
if (BP_IS_EMBEDDED(bp))
return (zio_null(pio, spa, NULL, NULL, NULL, 0));
metaslab_check_free(spa, bp);
arc_freed(spa, bp);
dsl_scan_freed(spa, bp);
/*
* GANG and DEDUP blocks can induce a read (for the gang block header,
* or the DDT), so issue them asynchronously so that this thread is
* not tied up.
*/
if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp))
stage |= ZIO_STAGE_ISSUE_ASYNC;
zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
BP_GET_PSIZE(bp), NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW,
flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage);
return (zio);
}
zio_t *
zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
zio_done_func_t *done, void *private, enum zio_flag flags)
{
zio_t *zio;
zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER);
if (BP_IS_EMBEDDED(bp))
return (zio_null(pio, spa, NULL, NULL, NULL, 0));
/*
* 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.
* If txg == 0 we just verify that the block is claimable.
*/
ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <,
spa_min_claim_txg(spa));
ASSERT(txg == spa_min_claim_txg(spa) || txg == 0);
ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */
zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW,
flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
ASSERT0(zio->io_queued_timestamp);
return (zio);
}
zio_t *
zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
zio_done_func_t *done, void *private, enum zio_flag flags)
{
zio_t *zio;
int c;
if (vd->vdev_children == 0) {
zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
zio->io_cmd = cmd;
} else {
zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
for (c = 0; c < vd->vdev_children; c++)
zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
done, private, flags));
}
return (zio);
}
zio_t *
zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
zio_done_func_t *done, void *private, zio_priority_t priority,
enum zio_flag flags, enum trim_flag trim_flags)
{
zio_t *zio;
ASSERT0(vd->vdev_children);
ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift));
ASSERT3U(size, !=, 0);
zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done,
private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL,
vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE);
zio->io_trim_flags = trim_flags;
return (zio);
}
zio_t *
zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
abd_t *data, int checksum, zio_done_func_t *done, void *private,
zio_priority_t priority, enum zio_flag flags, boolean_t labels)
{
zio_t *zio;
ASSERT(vd->vdev_children == 0);
ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
ASSERT3U(offset + size, <=, vd->vdev_psize);
zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd,
offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
zio->io_prop.zp_checksum = checksum;
return (zio);
}
zio_t *
zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
abd_t *data, int checksum, zio_done_func_t *done, void *private,
zio_priority_t priority, enum zio_flag flags, boolean_t labels)
{
zio_t *zio;
ASSERT(vd->vdev_children == 0);
ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
ASSERT3U(offset + size, <=, vd->vdev_psize);
zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd,
offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
zio->io_prop.zp_checksum = checksum;
if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
/*
* zec checksums are necessarily destructive -- they modify
* the end 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 in parallel.
*/
abd_t *wbuf = abd_alloc_sametype(data, size);
abd_copy(wbuf, data, size);
zio_push_transform(zio, wbuf, size, size, NULL);
}
return (zio);
}
/*
* Create a child I/O to do some work for us.
*/
zio_t *
zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
abd_t *data, uint64_t size, int type, zio_priority_t priority,
enum zio_flag flags, zio_done_func_t *done, void *private)
{
enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
zio_t *zio;
/*
* vdev child I/Os do not propagate their error to the parent.
* Therefore, for correct operation the caller *must* check for
* and handle the error in the child i/o's done callback.
* The only exceptions are i/os that we don't care about
* (OPTIONAL or REPAIR).
*/
ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) ||
done != NULL);
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 |= ZIO_STAGE_CHECKSUM_VERIFY;
pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
}
if (vd->vdev_ops->vdev_op_leaf) {
ASSERT0(vd->vdev_children);
offset += VDEV_LABEL_START_SIZE;
}
flags |= ZIO_VDEV_CHILD_FLAGS(pio);
/*
* If we've decided to do a repair, the write is not speculative --
* even if the original read was.
*/
if (flags & ZIO_FLAG_IO_REPAIR)
flags &= ~ZIO_FLAG_SPECULATIVE;
/*
* If we're creating a child I/O that is not associated with a
* top-level vdev, then the child zio is not an allocating I/O.
* If this is a retried I/O then we ignore it since we will
* have already processed the original allocating I/O.
*/
if (flags & ZIO_FLAG_IO_ALLOCATING &&
(vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) {
ASSERT(pio->io_metaslab_class != NULL);
ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled);
ASSERT(type == ZIO_TYPE_WRITE);
ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(!(flags & ZIO_FLAG_IO_REPAIR));
ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) ||
pio->io_child_type == ZIO_CHILD_GANG);
flags &= ~ZIO_FLAG_IO_ALLOCATING;
}
zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size,
done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
zio->io_physdone = pio->io_physdone;
if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL)
zio->io_logical->io_phys_children++;
return (zio);
}
zio_t *
zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
zio_type_t type, zio_priority_t priority, enum zio_flag flags,
zio_done_func_t *done, void *private)
{
zio_t *zio;
ASSERT(vd->vdev_ops->vdev_op_leaf);
zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
data, size, size, done, private, type, priority,
flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED,
vd, offset, NULL,
ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
return (zio);
}
void
zio_flush(zio_t *zio, vdev_t *vd)
{
zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
NULL, NULL,
ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
}
void
zio_shrink(zio_t *zio, uint64_t size)
{
ASSERT3P(zio->io_executor, ==, NULL);
ASSERT3U(zio->io_orig_size, ==, zio->io_size);
ASSERT3U(size, <=, zio->io_size);
/*
* We don't shrink for raidz because of problems with the
* reconstruction when reading back less than the block size.
* Note, BP_IS_RAIDZ() assumes no compression.
*/
ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
if (!BP_IS_RAIDZ(zio->io_bp)) {
/* we are not doing a raw write */
ASSERT3U(zio->io_size, ==, zio->io_lsize);
zio->io_orig_size = zio->io_size = zio->io_lsize = size;
}
}
/*
* ==========================================================================
* Prepare to read and write logical blocks
* ==========================================================================
*/
static zio_t *
zio_read_bp_init(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
uint64_t psize =
BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp);
ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
zio->io_child_type == ZIO_CHILD_LOGICAL &&
!(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
psize, psize, zio_decompress);
}
if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) ||
BP_HAS_INDIRECT_MAC_CKSUM(bp)) &&
zio->io_child_type == ZIO_CHILD_LOGICAL) {
zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
psize, psize, zio_decrypt);
}
if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) {
int psize = BPE_GET_PSIZE(bp);
void *data = abd_borrow_buf(zio->io_abd, psize);
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
decode_embedded_bp_compressed(bp, data);
abd_return_buf_copy(zio->io_abd, data, psize);
} else {
ASSERT(!BP_IS_EMBEDDED(bp));
ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
}
if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
zio->io_flags |= ZIO_FLAG_DONT_CACHE;
if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
zio->io_flags |= ZIO_FLAG_DONT_CACHE;
if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
return (zio);
}
static zio_t *
zio_write_bp_init(zio_t *zio)
{
if (!IO_IS_ALLOCATING(zio))
return (zio);
ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
if (zio->io_bp_override) {
blkptr_t *bp = zio->io_bp;
zio_prop_t *zp = &zio->io_prop;
ASSERT(bp->blk_birth != zio->io_txg);
ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
*bp = *zio->io_bp_override;
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
if (BP_IS_EMBEDDED(bp))
return (zio);
/*
* If we've been overridden and nopwrite is set then
* set the flag accordingly to indicate that a nopwrite
* has already occurred.
*/
if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
ASSERT(!zp->zp_dedup);
ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum);
zio->io_flags |= ZIO_FLAG_NOPWRITE;
return (zio);
}
ASSERT(!zp->zp_nopwrite);
if (BP_IS_HOLE(bp) || !zp->zp_dedup)
return (zio);
ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags &
ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify);
if (BP_GET_CHECKSUM(bp) == zp->zp_checksum &&
!zp->zp_encrypt) {
BP_SET_DEDUP(bp, 1);
zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
return (zio);
}
/*
* We were unable to handle this as an override bp, treat
* it as a regular write I/O.
*/
zio->io_bp_override = NULL;
*bp = zio->io_bp_orig;
zio->io_pipeline = zio->io_orig_pipeline;
}
return (zio);
}
static zio_t *
zio_write_compress(zio_t *zio)
{
spa_t *spa = zio->io_spa;
zio_prop_t *zp = &zio->io_prop;
enum zio_compress compress = zp->zp_compress;
blkptr_t *bp = zio->io_bp;
uint64_t lsize = zio->io_lsize;
uint64_t psize = zio->io_size;
int pass = 1;
/*
* If our children haven't all reached the ready stage,
* wait for them and then repeat this pipeline stage.
*/
if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT |
ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) {
return (NULL);
}
if (!IO_IS_ALLOCATING(zio))
return (zio);
if (zio->io_children_ready != NULL) {
/*
* Now that all our children are ready, run the callback
* associated with this zio in case it wants to modify the
* data to be written.
*/
ASSERT3U(zp->zp_level, >, 0);
zio->io_children_ready(zio);
}
ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
ASSERT(zio->io_bp_override == NULL);
if (!BP_IS_HOLE(bp) && 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(spa);
ASSERT(zio->io_txg == spa_syncing_txg(spa));
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(!BP_GET_DEDUP(bp));
if (pass >= zfs_sync_pass_dont_compress)
compress = ZIO_COMPRESS_OFF;
/* Make sure someone doesn't change their mind on overwrites */
ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp),
spa_max_replication(spa)) == BP_GET_NDVAS(bp));
}
/* If it's a compressed write that is not raw, compress the buffer. */
if (compress != ZIO_COMPRESS_OFF &&
!(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
void *cbuf = zio_buf_alloc(lsize);
psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize);
if (psize == 0 || psize == lsize) {
compress = ZIO_COMPRESS_OFF;
zio_buf_free(cbuf, lsize);
} else if (!zp->zp_dedup && !zp->zp_encrypt &&
psize <= BPE_PAYLOAD_SIZE &&
zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) &&
spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) {
encode_embedded_bp_compressed(bp,
cbuf, compress, lsize, psize);
BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA);
BP_SET_TYPE(bp, zio->io_prop.zp_type);
BP_SET_LEVEL(bp, zio->io_prop.zp_level);
zio_buf_free(cbuf, lsize);
bp->blk_birth = zio->io_txg;
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
ASSERT(spa_feature_is_active(spa,
SPA_FEATURE_EMBEDDED_DATA));
return (zio);
} else {
/*
* Round up compressed size up to the ashift
* of the smallest-ashift device, and zero the tail.
* This ensures that the compressed size of the BP
* (and thus compressratio property) are correct,
* in that we charge for the padding used to fill out
* the last sector.
*/
ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT);
size_t rounded = (size_t)P2ROUNDUP(psize,
1ULL << spa->spa_min_ashift);
if (rounded >= lsize) {
compress = ZIO_COMPRESS_OFF;
zio_buf_free(cbuf, lsize);
psize = lsize;
} else {
abd_t *cdata = abd_get_from_buf(cbuf, lsize);
abd_take_ownership_of_buf(cdata, B_TRUE);
abd_zero_off(cdata, psize, rounded - psize);
psize = rounded;
zio_push_transform(zio, cdata,
psize, lsize, NULL);
}
}
/*
* We were unable to handle this as an override bp, treat
* it as a regular write I/O.
*/
zio->io_bp_override = NULL;
*bp = zio->io_bp_orig;
zio->io_pipeline = zio->io_orig_pipeline;
} else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 &&
zp->zp_type == DMU_OT_DNODE) {
/*
* The DMU actually relies on the zio layer's compression
* to free metadnode blocks that have had all contained
* dnodes freed. As a result, even when doing a raw
* receive, we must check whether the block can be compressed
* to a hole.
*/
psize = zio_compress_data(ZIO_COMPRESS_EMPTY,
zio->io_abd, NULL, lsize);
if (psize == 0)
compress = ZIO_COMPRESS_OFF;
} else {
ASSERT3U(psize, !=, 0);
}
/*
* 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 allocate new blocks, but force rewrites after that.
* There should only be a handful of blocks after pass 1 in any case.
*/
if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg &&
BP_GET_PSIZE(bp) == psize &&
pass >= zfs_sync_pass_rewrite) {
VERIFY3U(psize, !=, 0);
enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
zio->io_flags |= ZIO_FLAG_IO_REWRITE;
} else {
BP_ZERO(bp);
zio->io_pipeline = ZIO_WRITE_PIPELINE;
}
if (psize == 0) {
if (zio->io_bp_orig.blk_birth != 0 &&
spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
BP_SET_LSIZE(bp, lsize);
BP_SET_TYPE(bp, zp->zp_type);
BP_SET_LEVEL(bp, zp->zp_level);
BP_SET_BIRTH(bp, zio->io_txg, 0);
}
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
} else {
ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
BP_SET_LSIZE(bp, lsize);
BP_SET_TYPE(bp, zp->zp_type);
BP_SET_LEVEL(bp, zp->zp_level);
BP_SET_PSIZE(bp, psize);
BP_SET_COMPRESS(bp, compress);
BP_SET_CHECKSUM(bp, zp->zp_checksum);
BP_SET_DEDUP(bp, zp->zp_dedup);
BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
if (zp->zp_dedup) {
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
ASSERT(!zp->zp_encrypt ||
DMU_OT_IS_ENCRYPTED(zp->zp_type));
zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
}
if (zp->zp_nopwrite) {
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
}
}
return (zio);
}
static zio_t *
zio_free_bp_init(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
if (BP_GET_DEDUP(bp))
zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
}
ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
return (zio);
}
/*
* ==========================================================================
* Execute the I/O pipeline
* ==========================================================================
*/
static void
zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
{
spa_t *spa = zio->io_spa;
zio_type_t t = zio->io_type;
int flags = (cutinline ? TQ_FRONT : 0);
/*
* If we're a config writer or a probe, the normal issue and
* interrupt threads may all be blocked waiting for the config lock.
* In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
*/
if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
t = ZIO_TYPE_NULL;
/*
* A similar issue exists for the L2ARC write thread until L2ARC 2.0.
*/
if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
t = ZIO_TYPE_NULL;
/*
* If this is a high priority I/O, then use the high priority taskq if
* available.
*/
if ((zio->io_priority == ZIO_PRIORITY_NOW ||
zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) &&
spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
q++;
ASSERT3U(q, <, ZIO_TASKQ_TYPES);
/*
* NB: We are assuming that the zio can only be dispatched
* to a single taskq at a time. It would be a grievous error
* to dispatch the zio to another taskq at the same time.
*/
ASSERT(taskq_empty_ent(&zio->io_tqent));
spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio,
flags, &zio->io_tqent);
}
static boolean_t
zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
{
kthread_t *executor = zio->io_executor;
spa_t *spa = zio->io_spa;
for (zio_type_t t = 0; t < ZIO_TYPES; t++) {
spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
uint_t i;
for (i = 0; i < tqs->stqs_count; i++) {
if (taskq_member(tqs->stqs_taskq[i], executor))
return (B_TRUE);
}
}
return (B_FALSE);
}
static zio_t *
zio_issue_async(zio_t *zio)
{
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
return (NULL);
}
void
zio_interrupt(zio_t *zio)
{
zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
}
void
zio_delay_interrupt(zio_t *zio)
{
/*
* The timeout_generic() function isn't defined in userspace, so
* rather than trying to implement the function, the zio delay
* functionality has been disabled for userspace builds.
*/
#ifdef _KERNEL
/*
* If io_target_timestamp is zero, then no delay has been registered
* for this IO, thus jump to the end of this function and "skip" the
* delay; issuing it directly to the zio layer.
*/
if (zio->io_target_timestamp != 0) {
hrtime_t now = gethrtime();
if (now >= zio->io_target_timestamp) {
/*
* This IO has already taken longer than the target
* delay to complete, so we don't want to delay it
* any longer; we "miss" the delay and issue it
* directly to the zio layer. This is likely due to
* the target latency being set to a value less than
* the underlying hardware can satisfy (e.g. delay
* set to 1ms, but the disks take 10ms to complete an
* IO request).
*/
DTRACE_PROBE2(zio__delay__miss, zio_t *, zio,
hrtime_t, now);
zio_interrupt(zio);
} else {
taskqid_t tid;
hrtime_t diff = zio->io_target_timestamp - now;
clock_t expire_at_tick = ddi_get_lbolt() +
NSEC_TO_TICK(diff);
DTRACE_PROBE3(zio__delay__hit, zio_t *, zio,
hrtime_t, now, hrtime_t, diff);
if (NSEC_TO_TICK(diff) == 0) {
/* Our delay is less than a jiffy - just spin */
zfs_sleep_until(zio->io_target_timestamp);
zio_interrupt(zio);
} else {
/*
* Use taskq_dispatch_delay() in the place of
* OpenZFS's timeout_generic().
*/
tid = taskq_dispatch_delay(system_taskq,
(task_func_t *)zio_interrupt,
zio, TQ_NOSLEEP, expire_at_tick);
if (tid == TASKQID_INVALID) {
/*
* Couldn't allocate a task. Just
* finish the zio without a delay.
*/
zio_interrupt(zio);
}
}
}
return;
}
#endif
DTRACE_PROBE1(zio__delay__skip, zio_t *, zio);
zio_interrupt(zio);
}
static void
zio_deadman_impl(zio_t *pio, int ziodepth)
{
zio_t *cio, *cio_next;
zio_link_t *zl = NULL;
vdev_t *vd = pio->io_vd;
if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) {
vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL;
zbookmark_phys_t *zb = &pio->io_bookmark;
uint64_t delta = gethrtime() - pio->io_timestamp;
uint64_t failmode = spa_get_deadman_failmode(pio->io_spa);
zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu "
"delta=%llu queued=%llu io=%llu "
"path=%s last=%llu "
"type=%d priority=%d flags=0x%x "
"stage=0x%x pipeline=0x%x pipeline-trace=0x%x "
"objset=%llu object=%llu level=%llu blkid=%llu "
"offset=%llu size=%llu error=%d",
ziodepth, pio, pio->io_timestamp,
delta, pio->io_delta, pio->io_delay,
vd ? vd->vdev_path : "NULL", vq ? vq->vq_io_complete_ts : 0,
pio->io_type, pio->io_priority, pio->io_flags,
pio->io_stage, pio->io_pipeline, pio->io_pipeline_trace,
zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid,
pio->io_offset, pio->io_size, pio->io_error);
zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN,
pio->io_spa, vd, zb, pio, 0, 0);
if (failmode == ZIO_FAILURE_MODE_CONTINUE &&
taskq_empty_ent(&pio->io_tqent)) {
zio_interrupt(pio);
}
}
mutex_enter(&pio->io_lock);
for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
cio_next = zio_walk_children(pio, &zl);
zio_deadman_impl(cio, ziodepth + 1);
}
mutex_exit(&pio->io_lock);
}
/*
* Log the critical information describing this zio and all of its children
* using the zfs_dbgmsg() interface then post deadman event for the ZED.
*/
void
zio_deadman(zio_t *pio, char *tag)
{
spa_t *spa = pio->io_spa;
char *name = spa_name(spa);
if (!zfs_deadman_enabled || spa_suspended(spa))
return;
zio_deadman_impl(pio, 0);
switch (spa_get_deadman_failmode(spa)) {
case ZIO_FAILURE_MODE_WAIT:
zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name);
break;
case ZIO_FAILURE_MODE_CONTINUE:
zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name);
break;
case ZIO_FAILURE_MODE_PANIC:
fm_panic("%s determined I/O to pool '%s' is hung.", tag, name);
break;
}
}
/*
* 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_io().
*
* 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.
*/
static zio_pipe_stage_t *zio_pipeline[];
/*
* zio_execute() is a wrapper around the static function
* __zio_execute() so that we can force __zio_execute() to be
* inlined. This reduces stack overhead which is important
* because __zio_execute() is called recursively in several zio
* code paths. zio_execute() itself cannot be inlined because
* it is externally visible.
*/
void
zio_execute(zio_t *zio)
{
fstrans_cookie_t cookie;
cookie = spl_fstrans_mark();
__zio_execute(zio);
spl_fstrans_unmark(cookie);
}
/*
* Used to determine if in the current context the stack is sized large
* enough to allow zio_execute() to be called recursively. A minimum
* stack size of 16K is required to avoid needing to re-dispatch the zio.
*/
boolean_t
zio_execute_stack_check(zio_t *zio)
{
#if !defined(HAVE_LARGE_STACKS)
dsl_pool_t *dp = spa_get_dsl(zio->io_spa);
/* Executing in txg_sync_thread() context. */
if (dp && curthread == dp->dp_tx.tx_sync_thread)
return (B_TRUE);
/* Pool initialization outside of zio_taskq context. */
if (dp && spa_is_initializing(dp->dp_spa) &&
!zio_taskq_member(zio, ZIO_TASKQ_ISSUE) &&
!zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH))
return (B_TRUE);
#endif /* HAVE_LARGE_STACKS */
return (B_FALSE);
}
__attribute__((always_inline))
static inline void
__zio_execute(zio_t *zio)
{
ASSERT3U(zio->io_queued_timestamp, >, 0);
while (zio->io_stage < ZIO_STAGE_DONE) {
enum zio_stage pipeline = zio->io_pipeline;
enum zio_stage stage = zio->io_stage;
zio->io_executor = curthread;
ASSERT(!MUTEX_HELD(&zio->io_lock));
ASSERT(ISP2(stage));
ASSERT(zio->io_stall == NULL);
do {
stage <<= 1;
} while ((stage & pipeline) == 0);
ASSERT(stage <= ZIO_STAGE_DONE);
/*
* If we are in interrupt context and this pipeline stage
* will grab a config lock that is held across I/O,
* or may wait for an I/O that needs an interrupt thread
* to complete, issue async to avoid deadlock.
*
* For VDEV_IO_START, we cut in line so that the io will
* be sent to disk promptly.
*/
if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
zio_requeue_io_start_cut_in_line : B_FALSE;
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
return;
}
/*
* If the current context doesn't have large enough stacks
* the zio must be issued asynchronously to prevent overflow.
*/
if (zio_execute_stack_check(zio)) {
boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
zio_requeue_io_start_cut_in_line : B_FALSE;
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
return;
}
zio->io_stage = stage;
zio->io_pipeline_trace |= zio->io_stage;
/*
* The zio pipeline stage returns the next zio to execute
* (typically the same as this one), or NULL if we should
* stop.
*/
zio = zio_pipeline[highbit64(stage) - 1](zio);
if (zio == NULL)
return;
}
}
/*
* ==========================================================================
* Initiate I/O, either sync or async
* ==========================================================================
*/
int
zio_wait(zio_t *zio)
{
long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms);
int error;
ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN);
ASSERT3P(zio->io_executor, ==, NULL);
zio->io_waiter = curthread;
ASSERT0(zio->io_queued_timestamp);
zio->io_queued_timestamp = gethrtime();
__zio_execute(zio);
mutex_enter(&zio->io_lock);
while (zio->io_executor != NULL) {
error = cv_timedwait_io(&zio->io_cv, &zio->io_lock,
ddi_get_lbolt() + timeout);
if (zfs_deadman_enabled && error == -1 &&
gethrtime() - zio->io_queued_timestamp >
spa_deadman_ziotime(zio->io_spa)) {
mutex_exit(&zio->io_lock);
timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms);
zio_deadman(zio, FTAG);
mutex_enter(&zio->io_lock);
}
}
mutex_exit(&zio->io_lock);
error = zio->io_error;
zio_destroy(zio);
return (error);
}
void
zio_nowait(zio_t *zio)
{
ASSERT3P(zio->io_executor, ==, NULL);
if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
zio_unique_parent(zio) == NULL) {
zio_t *pio;
/*
* This is a logical async I/O with no parent to wait for it.
* We add it to the spa_async_root_zio "Godfather" I/O which
* will ensure they complete prior to unloading the pool.
*/
spa_t *spa = zio->io_spa;
kpreempt_disable();
pio = spa->spa_async_zio_root[CPU_SEQID];
kpreempt_enable();
zio_add_child(pio, zio);
}
ASSERT0(zio->io_queued_timestamp);
zio->io_queued_timestamp = gethrtime();
__zio_execute(zio);
}
/*
* ==========================================================================
* Reexecute, cancel, or suspend/resume failed I/O
* ==========================================================================
*/
static void
zio_reexecute(zio_t *pio)
{
zio_t *cio, *cio_next;
ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
ASSERT(pio->io_gang_leader == NULL);
ASSERT(pio->io_gang_tree == NULL);
pio->io_flags = pio->io_orig_flags;
pio->io_stage = pio->io_orig_stage;
pio->io_pipeline = pio->io_orig_pipeline;
pio->io_reexecute = 0;
pio->io_flags |= ZIO_FLAG_REEXECUTED;
pio->io_pipeline_trace = 0;
pio->io_error = 0;
for (int w = 0; w < ZIO_WAIT_TYPES; w++)
pio->io_state[w] = 0;
for (int c = 0; c < ZIO_CHILD_TYPES; c++)
pio->io_child_error[c] = 0;
if (IO_IS_ALLOCATING(pio))
BP_ZERO(pio->io_bp);
/*
* As we reexecute pio's children, new children could be created.
* New children go to the head of pio's io_child_list, however,
* so we will (correctly) not reexecute them. The key is that
* the remainder of pio's io_child_list, from 'cio_next' onward,
* cannot be affected by any side effects of reexecuting 'cio'.
*/
zio_link_t *zl = NULL;
mutex_enter(&pio->io_lock);
for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
cio_next = zio_walk_children(pio, &zl);
for (int w = 0; w < ZIO_WAIT_TYPES; w++)
pio->io_children[cio->io_child_type][w]++;
mutex_exit(&pio->io_lock);
zio_reexecute(cio);
mutex_enter(&pio->io_lock);
}
mutex_exit(&pio->io_lock);
/*
* Now that all children have been reexecuted, execute the parent.
* We don't reexecute "The Godfather" I/O here as it's the
* responsibility of the caller to wait on it.
*/
if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) {
pio->io_queued_timestamp = gethrtime();
__zio_execute(pio);
}
}
void
zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
{
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 "
"failure and has been suspended.\n", spa_name(spa));
zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL,
NULL, NULL, 0, 0);
mutex_enter(&spa->spa_suspend_lock);
if (spa->spa_suspend_zio_root == NULL)
spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
ZIO_FLAG_GODFATHER);
spa->spa_suspended = reason;
if (zio != NULL) {
ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
ASSERT(zio != spa->spa_suspend_zio_root);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(zio_unique_parent(zio) == NULL);
ASSERT(zio->io_stage == ZIO_STAGE_DONE);
zio_add_child(spa->spa_suspend_zio_root, zio);
}
mutex_exit(&spa->spa_suspend_lock);
}
int
zio_resume(spa_t *spa)
{
zio_t *pio;
/*
* Reexecute all previously suspended i/o.
*/
mutex_enter(&spa->spa_suspend_lock);
spa->spa_suspended = ZIO_SUSPEND_NONE;
cv_broadcast(&spa->spa_suspend_cv);
pio = spa->spa_suspend_zio_root;
spa->spa_suspend_zio_root = NULL;
mutex_exit(&spa->spa_suspend_lock);
if (pio == NULL)
return (0);
zio_reexecute(pio);
return (zio_wait(pio));
}
void
zio_resume_wait(spa_t *spa)
{
mutex_enter(&spa->spa_suspend_lock);
while (spa_suspended(spa))
cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
mutex_exit(&spa->spa_suspend_lock);
}
/*
* ==========================================================================
* Gang blocks.
*
* A gang block is a collection of small blocks that looks to the DMU
* like one large block. When zio_dva_allocate() cannot find a block
* of the requested size, due to either severe fragmentation or the pool
* being nearly full, it calls zio_write_gang_block() to construct the
* block from smaller fragments.
*
* A gang block consists of a gang header (zio_gbh_phys_t) and up to
* three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
* an indirect block: it's an array of block pointers. It consumes
* only one sector and hence is allocatable regardless of fragmentation.
* The gang header's bps point to its gang members, which hold the data.
*
* Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
* as the verifier to ensure uniqueness of the SHA256 checksum.
* Critically, the gang block bp's blk_cksum is the checksum of the data,
* not the gang header. This ensures that data block signatures (needed for
* deduplication) are independent of how the block is physically stored.
*
* Gang blocks can be nested: a gang member may itself be a gang block.
* Thus every gang block is a tree in which root and all interior nodes are
* gang headers, and the leaves are normal blocks that contain user data.
* The root of the gang tree is called the gang leader.
*
* To perform any operation (read, rewrite, free, claim) on a gang block,
* zio_gang_assemble() first assembles the gang tree (minus data leaves)
* in the io_gang_tree field of the original logical i/o by recursively
* reading the gang leader and all gang headers below it. This yields
* an in-core tree containing the contents of every gang header and the
* bps for every constituent of the gang block.
*
* With the gang tree now assembled, zio_gang_issue() just walks the gang tree
* and invokes a callback on each bp. To free a gang block, zio_gang_issue()
* calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
* zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
* zio_read_gang() is a wrapper around zio_read() that omits reading gang
* headers, since we already have those in io_gang_tree. zio_rewrite_gang()
* performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
* of the gang header plus zio_checksum_compute() of the data to update the
* gang header's blk_cksum as described above.
*
* The two-phase assemble/issue model solves the problem of partial failure --
* what if you'd freed part of a gang block but then couldn't read the
* gang header for another part? Assembling the entire gang tree first
* ensures that all the necessary gang header I/O has succeeded before
* starting the actual work of free, claim, or write. Once the gang tree
* is assembled, free and claim are in-memory operations that cannot fail.
*
* In the event that a gang write fails, zio_dva_unallocate() walks the
* gang tree to immediately free (i.e. insert back into the space map)
* everything we've allocated. This ensures that we don't get ENOSPC
* errors during repeated suspend/resume cycles due to a flaky device.
*
* Gang rewrites only happen during sync-to-convergence. If we can't assemble
* the gang tree, we won't modify the block, so we can safely defer the free
* (knowing that the block is still intact). If we *can* assemble the gang
* tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
* each constituent bp and we can allocate a new block on the next sync pass.
*
* In all cases, the gang tree allows complete recovery from partial failure.
* ==========================================================================
*/
static void
zio_gang_issue_func_done(zio_t *zio)
{
abd_put(zio->io_abd);
}
static zio_t *
zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
uint64_t offset)
{
if (gn != NULL)
return (pio);
return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset),
BP_GET_PSIZE(bp), zio_gang_issue_func_done,
NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
&pio->io_bookmark));
}
static zio_t *
zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
uint64_t offset)
{
zio_t *zio;
if (gn != NULL) {
abd_t *gbh_abd =
abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL,
pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
&pio->io_bookmark);
/*
* As we rewrite each gang header, the pipeline will compute
* a new gang block header checksum for it; but no one will
* compute a new data checksum, so we do that here. The one
* exception is the gang leader: the pipeline already computed
* its data checksum because that stage precedes gang assembly.
* (Presently, nothing actually uses interior data checksums;
* this is just good hygiene.)
*/
if (gn != pio->io_gang_leader->io_gang_tree) {
abd_t *buf = abd_get_offset(data, offset);
zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
buf, BP_GET_PSIZE(bp));
abd_put(buf);
}
/*
* If we are here to damage data for testing purposes,
* leave the GBH alone so that we can detect the damage.
*/
if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
} else {
zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
abd_get_offset(data, offset), BP_GET_PSIZE(bp),
zio_gang_issue_func_done, NULL, pio->io_priority,
ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
}
return (zio);
}
/* ARGSUSED */
static zio_t *
zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
uint64_t offset)
{
return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
ZIO_GANG_CHILD_FLAGS(pio)));
}
/* ARGSUSED */
static zio_t *
zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
uint64_t offset)
{
return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
}
static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
NULL,
zio_read_gang,
zio_rewrite_gang,
zio_free_gang,
zio_claim_gang,
NULL
};
static void zio_gang_tree_assemble_done(zio_t *zio);
static zio_gang_node_t *
zio_gang_node_alloc(zio_gang_node_t **gnpp)
{
zio_gang_node_t *gn;
ASSERT(*gnpp == NULL);
gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
*gnpp = gn;
return (gn);
}
static void
zio_gang_node_free(zio_gang_node_t **gnpp)
{
zio_gang_node_t *gn = *gnpp;
for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
ASSERT(gn->gn_child[g] == NULL);
zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
kmem_free(gn, sizeof (*gn));
*gnpp = NULL;
}
static void
zio_gang_tree_free(zio_gang_node_t **gnpp)
{
zio_gang_node_t *gn = *gnpp;
if (gn == NULL)
return;
for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
zio_gang_tree_free(&gn->gn_child[g]);
zio_gang_node_free(gnpp);
}
static void
zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
{
zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
ASSERT(gio->io_gang_leader == gio);
ASSERT(BP_IS_GANG(bp));
zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE,
zio_gang_tree_assemble_done, gn, gio->io_priority,
ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
}
static void
zio_gang_tree_assemble_done(zio_t *zio)
{
zio_t *gio = zio->io_gang_leader;
zio_gang_node_t *gn = zio->io_private;
blkptr_t *bp = zio->io_bp;
ASSERT(gio == zio_unique_parent(zio));
ASSERT(zio->io_child_count == 0);
if (zio->io_error)
return;
/* this ABD was created from a linear buf in zio_gang_tree_assemble */
if (BP_SHOULD_BYTESWAP(bp))
byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size);
ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh);
ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
abd_put(zio->io_abd);
for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
if (!BP_IS_GANG(gbp))
continue;
zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
}
}
static void
zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data,
uint64_t offset)
{
zio_t *gio = pio->io_gang_leader;
zio_t *zio;
ASSERT(BP_IS_GANG(bp) == !!gn);
ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
/*
* If you're a gang header, your data is in gn->gn_gbh.
* If you're a gang member, your data is in 'data' and gn == NULL.
*/
zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset);
if (gn != NULL) {
ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
if (BP_IS_HOLE(gbp))
continue;
zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data,
offset);
offset += BP_GET_PSIZE(gbp);
}
}
if (gn == gio->io_gang_tree)
ASSERT3U(gio->io_size, ==, offset);
if (zio != pio)
zio_nowait(zio);
}
static zio_t *
zio_gang_assemble(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
zio->io_gang_leader = zio;
zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
return (zio);
}
static zio_t *
zio_gang_issue(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) {
return (NULL);
}
ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd,
0);
else
zio_gang_tree_free(&zio->io_gang_tree);
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
return (zio);
}
static void
zio_write_gang_member_ready(zio_t *zio)
{
zio_t *pio = zio_unique_parent(zio);
dva_t *cdva = zio->io_bp->blk_dva;
dva_t *pdva = pio->io_bp->blk_dva;
uint64_t asize;
ASSERTV(zio_t *gio = zio->io_gang_leader);
if (BP_IS_HOLE(zio->io_bp))
return;
ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
mutex_enter(&pio->io_lock);
for (int d = 0; d < BP_GET_NDVAS(zio->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 void
zio_write_gang_done(zio_t *zio)
{
/*
* The io_abd field will be NULL for a zio with no data. The io_flags
* will initially have the ZIO_FLAG_NODATA bit flag set, but we can't
* check for it here as it is cleared in zio_ready.
*/
if (zio->io_abd != NULL)
abd_put(zio->io_abd);
}
static zio_t *
zio_write_gang_block(zio_t *pio)
{
spa_t *spa = pio->io_spa;
metaslab_class_t *mc = spa_normal_class(spa);
blkptr_t *bp = pio->io_bp;
zio_t *gio = pio->io_gang_leader;
zio_t *zio;
zio_gang_node_t *gn, **gnpp;
zio_gbh_phys_t *gbh;
abd_t *gbh_abd;
uint64_t txg = pio->io_txg;
uint64_t resid = pio->io_size;
uint64_t lsize;
int copies = gio->io_prop.zp_copies;
int gbh_copies;
zio_prop_t zp;
int error;
boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA);
/*
* encrypted blocks need DVA[2] free so encrypted gang headers can't
* have a third copy.
*/
gbh_copies = MIN(copies + 1, spa_max_replication(spa));
if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP)
gbh_copies = SPA_DVAS_PER_BP - 1;
int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER;
if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(has_data);
flags |= METASLAB_ASYNC_ALLOC;
VERIFY(zfs_refcount_held(&mc->mc_alloc_slots[pio->io_allocator],
pio));
/*
* The logical zio has already placed a reservation for
* 'copies' allocation slots but gang blocks may require
* additional copies. These additional copies
* (i.e. gbh_copies - copies) are guaranteed to succeed
* since metaslab_class_throttle_reserve() always allows
* additional reservations for gang blocks.
*/
VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies,
pio->io_allocator, pio, flags));
}
error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE,
bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags,
&pio->io_alloc_list, pio, pio->io_allocator);
if (error) {
if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(has_data);
/*
* If we failed to allocate the gang block header then
* we remove any additional allocation reservations that
* we placed here. The original reservation will
* be removed when the logical I/O goes to the ready
* stage.
*/
metaslab_class_throttle_unreserve(mc,
gbh_copies - copies, pio->io_allocator, pio);
}
pio->io_error = error;
return (pio);
}
if (pio == gio) {
gnpp = &gio->io_gang_tree;
} else {
gnpp = pio->io_private;
ASSERT(pio->io_ready == zio_write_gang_member_ready);
}
gn = zio_gang_node_alloc(gnpp);
gbh = gn->gn_gbh;
bzero(gbh, SPA_GANGBLOCKSIZE);
gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE);
/*
* Create the gang header.
*/
zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE,
zio_write_gang_done, NULL, pio->io_priority,
ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
/*
* Create and nowait the gang children.
*/
for (int g = 0; resid != 0; resid -= lsize, g++) {
lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
SPA_MINBLOCKSIZE);
ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
zp.zp_checksum = gio->io_prop.zp_checksum;
zp.zp_compress = ZIO_COMPRESS_OFF;
zp.zp_type = DMU_OT_NONE;
zp.zp_level = 0;
zp.zp_copies = gio->io_prop.zp_copies;
zp.zp_dedup = B_FALSE;
zp.zp_dedup_verify = B_FALSE;
zp.zp_nopwrite = B_FALSE;
zp.zp_encrypt = gio->io_prop.zp_encrypt;
zp.zp_byteorder = gio->io_prop.zp_byteorder;
bzero(zp.zp_salt, ZIO_DATA_SALT_LEN);
bzero(zp.zp_iv, ZIO_DATA_IV_LEN);
bzero(zp.zp_mac, ZIO_DATA_MAC_LEN);
zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
has_data ? abd_get_offset(pio->io_abd, pio->io_size -
resid) : NULL, lsize, lsize, &zp,
zio_write_gang_member_ready, NULL, NULL,
zio_write_gang_done, &gn->gn_child[g], pio->io_priority,
ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(has_data);
/*
* Gang children won't throttle but we should
* account for their work, so reserve an allocation
* slot for them here.
*/
VERIFY(metaslab_class_throttle_reserve(mc,
zp.zp_copies, cio->io_allocator, cio, flags));
}
zio_nowait(cio);
}
/*
* Set pio's pipeline to just wait for zio to finish.
*/
pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
/*
* We didn't allocate this bp, so make sure it doesn't get unmarked.
*/
pio->io_flags &= ~ZIO_FLAG_FASTWRITE;
zio_nowait(zio);
return (pio);
}
/*
* The zio_nop_write stage in the pipeline determines if allocating a
* new bp is necessary. The nopwrite feature can handle writes in
* either syncing or open context (i.e. zil writes) and as a result is
* mutually exclusive with dedup.
*
* By leveraging a cryptographically secure checksum, such as SHA256, we
* can compare the checksums of the new data and the old to determine if
* allocating a new block is required. Note that our requirements for
* cryptographic strength are fairly weak: there can't be any accidental
* hash collisions, but we don't need to be secure against intentional
* (malicious) collisions. To trigger a nopwrite, you have to be able
* to write the file to begin with, and triggering an incorrect (hash
* collision) nopwrite is no worse than simply writing to the file.
* That said, there are no known attacks against the checksum algorithms
* used for nopwrite, assuming that the salt and the checksums
* themselves remain secret.
*/
static zio_t *
zio_nop_write(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
blkptr_t *bp_orig = &zio->io_bp_orig;
zio_prop_t *zp = &zio->io_prop;
ASSERT(BP_GET_LEVEL(bp) == 0);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
ASSERT(zp->zp_nopwrite);
ASSERT(!zp->zp_dedup);
ASSERT(zio->io_bp_override == NULL);
ASSERT(IO_IS_ALLOCATING(zio));
/*
* Check to see if the original bp and the new bp have matching
* characteristics (i.e. same checksum, compression algorithms, etc).
* If they don't then just continue with the pipeline which will
* allocate a new bp.
*/
if (BP_IS_HOLE(bp_orig) ||
!(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags &
ZCHECKSUM_FLAG_NOPWRITE) ||
BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) ||
BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
zp->zp_copies != BP_GET_NDVAS(bp_orig))
return (zio);
/*
* If the checksums match then reset the pipeline so that we
* avoid allocating a new bp and issuing any I/O.
*/
if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags &
ZCHECKSUM_FLAG_NOPWRITE);
ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
sizeof (uint64_t)) == 0);
/*
* If we're overwriting a block that is currently on an
* indirect vdev, then ignore the nopwrite request and
* allow a new block to be allocated on a concrete vdev.
*/
spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER);
vdev_t *tvd = vdev_lookup_top(zio->io_spa,
DVA_GET_VDEV(&bp->blk_dva[0]));
if (tvd->vdev_ops == &vdev_indirect_ops) {
spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
return (zio);
}
spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
*bp = *bp_orig;
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
zio->io_flags |= ZIO_FLAG_NOPWRITE;
}
return (zio);
}
/*
* ==========================================================================
* Dedup
* ==========================================================================
*/
static void
zio_ddt_child_read_done(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
ddt_entry_t *dde = zio->io_private;
ddt_phys_t *ddp;
zio_t *pio = zio_unique_parent(zio);
mutex_enter(&pio->io_lock);
ddp = ddt_phys_select(dde, bp);
if (zio->io_error == 0)
ddt_phys_clear(ddp); /* this ddp doesn't need repair */
if (zio->io_error == 0 && dde->dde_repair_abd == NULL)
dde->dde_repair_abd = zio->io_abd;
else
abd_free(zio->io_abd);
mutex_exit(&pio->io_lock);
}
static zio_t *
zio_ddt_read_start(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
ASSERT(BP_GET_DEDUP(bp));
ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
if (zio->io_child_error[ZIO_CHILD_DDT]) {
ddt_t *ddt = ddt_select(zio->io_spa, bp);
ddt_entry_t *dde = ddt_repair_start(ddt, bp);
ddt_phys_t *ddp = dde->dde_phys;
ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
blkptr_t blk;
ASSERT(zio->io_vsd == NULL);
zio->io_vsd = dde;
if (ddp_self == NULL)
return (zio);
for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
continue;
ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
&blk);
zio_nowait(zio_read(zio, zio->io_spa, &blk,
abd_alloc_for_io(zio->io_size, B_TRUE),
zio->io_size, zio_ddt_child_read_done, dde,
zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) |
ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark));
}
return (zio);
}
zio_nowait(zio_read(zio, zio->io_spa, bp,
zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority,
ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
return (zio);
}
static zio_t *
zio_ddt_read_done(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) {
return (NULL);
}
ASSERT(BP_GET_DEDUP(bp));
ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
if (zio->io_child_error[ZIO_CHILD_DDT]) {
ddt_t *ddt = ddt_select(zio->io_spa, bp);
ddt_entry_t *dde = zio->io_vsd;
if (ddt == NULL) {
ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
return (zio);
}
if (dde == NULL) {
zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
return (NULL);
}
if (dde->dde_repair_abd != NULL) {
abd_copy(zio->io_abd, dde->dde_repair_abd,
zio->io_size);
zio->io_child_error[ZIO_CHILD_DDT] = 0;
}
ddt_repair_done(ddt, dde);
zio->io_vsd = NULL;
}
ASSERT(zio->io_vsd == NULL);
return (zio);
}
static boolean_t
zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
{
spa_t *spa = zio->io_spa;
boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW);
ASSERT(!(zio->io_bp_override && do_raw));
/*
* Note: we compare the original data, not the transformed data,
* because when zio->io_bp is an override bp, we will not have
* pushed the I/O transforms. That's an important optimization
* because otherwise we'd compress/encrypt all dmu_sync() data twice.
* However, we should never get a raw, override zio so in these
* cases we can compare the io_abd directly. This is useful because
* it allows us to do dedup verification even if we don't have access
* to the original data (for instance, if the encryption keys aren't
* loaded).
*/
for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
zio_t *lio = dde->dde_lead_zio[p];
if (lio != NULL && do_raw) {
return (lio->io_size != zio->io_size ||
abd_cmp(zio->io_abd, lio->io_abd) != 0);
} else if (lio != NULL) {
return (lio->io_orig_size != zio->io_orig_size ||
abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0);
}
}
for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
ddt_phys_t *ddp = &dde->dde_phys[p];
if (ddp->ddp_phys_birth != 0 && do_raw) {
blkptr_t blk = *zio->io_bp;
uint64_t psize;
abd_t *tmpabd;
int error;
ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
psize = BP_GET_PSIZE(&blk);
if (psize != zio->io_size)
return (B_TRUE);
ddt_exit(ddt);
tmpabd = abd_alloc_for_io(psize, B_TRUE);
error = zio_wait(zio_read(NULL, spa, &blk, tmpabd,
psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
ZIO_FLAG_RAW, &zio->io_bookmark));
if (error == 0) {
if (abd_cmp(tmpabd, zio->io_abd) != 0)
error = SET_ERROR(ENOENT);
}
abd_free(tmpabd);
ddt_enter(ddt);
return (error != 0);
} else if (ddp->ddp_phys_birth != 0) {
arc_buf_t *abuf = NULL;
arc_flags_t aflags = ARC_FLAG_WAIT;
blkptr_t blk = *zio->io_bp;
int error;
ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
if (BP_GET_LSIZE(&blk) != zio->io_orig_size)
return (B_TRUE);
ddt_exit(ddt);
error = arc_read(NULL, spa, &blk,
arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
&aflags, &zio->io_bookmark);
if (error == 0) {
if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data,
zio->io_orig_size) != 0)
error = SET_ERROR(ENOENT);
arc_buf_destroy(abuf, &abuf);
}
ddt_enter(ddt);
return (error != 0);
}
}
return (B_FALSE);
}
static void
zio_ddt_child_write_ready(zio_t *zio)
{
int p = zio->io_prop.zp_copies;
ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
ddt_entry_t *dde = zio->io_private;
ddt_phys_t *ddp = &dde->dde_phys[p];
zio_t *pio;
if (zio->io_error)
return;
ddt_enter(ddt);
ASSERT(dde->dde_lead_zio[p] == zio);
ddt_phys_fill(ddp, zio->io_bp);
zio_link_t *zl = NULL;
while ((pio = zio_walk_parents(zio, &zl)) != NULL)
ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
ddt_exit(ddt);
}
static void
zio_ddt_child_write_done(zio_t *zio)
{
int p = zio->io_prop.zp_copies;
ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
ddt_entry_t *dde = zio->io_private;
ddt_phys_t *ddp = &dde->dde_phys[p];
ddt_enter(ddt);
ASSERT(ddp->ddp_refcnt == 0);
ASSERT(dde->dde_lead_zio[p] == zio);
dde->dde_lead_zio[p] = NULL;
if (zio->io_error == 0) {
zio_link_t *zl = NULL;
while (zio_walk_parents(zio, &zl) != NULL)
ddt_phys_addref(ddp);
} else {
ddt_phys_clear(ddp);
}
ddt_exit(ddt);
}
static void
zio_ddt_ditto_write_done(zio_t *zio)
{
int p = DDT_PHYS_DITTO;
ASSERTV(zio_prop_t *zp = &zio->io_prop);
blkptr_t *bp = zio->io_bp;
ddt_t *ddt = ddt_select(zio->io_spa, bp);
ddt_entry_t *dde = zio->io_private;
ddt_phys_t *ddp = &dde->dde_phys[p];
ddt_key_t *ddk = &dde->dde_key;
ddt_enter(ddt);
ASSERT(ddp->ddp_refcnt == 0);
ASSERT(dde->dde_lead_zio[p] == zio);
dde->dde_lead_zio[p] = NULL;
if (zio->io_error == 0) {
ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum));
ASSERT(zp->zp_copies < SPA_DVAS_PER_BP);
ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp));
if (ddp->ddp_phys_birth != 0)
ddt_phys_free(ddt, ddk, ddp, zio->io_txg);
ddt_phys_fill(ddp, bp);
}
ddt_exit(ddt);
}
static zio_t *
zio_ddt_write(zio_t *zio)
{
spa_t *spa = zio->io_spa;
blkptr_t *bp = zio->io_bp;
uint64_t txg = zio->io_txg;
zio_prop_t *zp = &zio->io_prop;
int p = zp->zp_copies;
int ditto_copies;
zio_t *cio = NULL;
zio_t *dio = NULL;
ddt_t *ddt = ddt_select(spa, bp);
ddt_entry_t *dde;
ddt_phys_t *ddp;
ASSERT(BP_GET_DEDUP(bp));
ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW)));
ddt_enter(ddt);
dde = ddt_lookup(ddt, bp, B_TRUE);
ddp = &dde->dde_phys[p];
if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
/*
* If we're using a weak checksum, upgrade to a strong checksum
* and try again. If we're already using a strong checksum,
* we can't resolve it, so just convert to an ordinary write.
* (And automatically e-mail a paper to Nature?)
*/
if (!(zio_checksum_table[zp->zp_checksum].ci_flags &
ZCHECKSUM_FLAG_DEDUP)) {
zp->zp_checksum = spa_dedup_checksum(spa);
zio_pop_transforms(zio);
zio->io_stage = ZIO_STAGE_OPEN;
BP_ZERO(bp);
} else {
zp->zp_dedup = B_FALSE;
BP_SET_DEDUP(bp, B_FALSE);
}
ASSERT(!BP_GET_DEDUP(bp));
zio->io_pipeline = ZIO_WRITE_PIPELINE;
ddt_exit(ddt);
return (zio);
}
ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp);
ASSERT(ditto_copies < SPA_DVAS_PER_BP);
if (ditto_copies > ddt_ditto_copies_present(dde) &&
dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) {
zio_prop_t czp = *zp;
czp.zp_copies = ditto_copies;
/*
* If we arrived here with an override bp, we won't have run
* the transform stack, so we won't have the data we need to
* generate a child i/o. So, toss the override bp and restart.
* This is safe, because using the override bp is just an
* optimization; and it's rare, so the cost doesn't matter.
*/
if (zio->io_bp_override) {
zio_pop_transforms(zio);
zio->io_stage = ZIO_STAGE_OPEN;
zio->io_pipeline = ZIO_WRITE_PIPELINE;
zio->io_bp_override = NULL;
BP_ZERO(bp);
ddt_exit(ddt);
return (zio);
}
dio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
zio->io_orig_size, zio->io_orig_size, &czp, NULL, NULL,
NULL, zio_ddt_ditto_write_done, dde, zio->io_priority,
ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
zio_push_transform(dio, zio->io_abd, zio->io_size, 0, NULL);
dde->dde_lead_zio[DDT_PHYS_DITTO] = dio;
}
if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
if (ddp->ddp_phys_birth != 0)
ddt_bp_fill(ddp, bp, txg);
if (dde->dde_lead_zio[p] != NULL)
zio_add_child(zio, dde->dde_lead_zio[p]);
else
ddt_phys_addref(ddp);
} else if (zio->io_bp_override) {
ASSERT(bp->blk_birth == txg);
ASSERT(BP_EQUAL(bp, zio->io_bp_override));
ddt_phys_fill(ddp, bp);
ddt_phys_addref(ddp);
} else {
cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
zio->io_orig_size, zio->io_orig_size, zp,
zio_ddt_child_write_ready, NULL, NULL,
zio_ddt_child_write_done, dde, zio->io_priority,
ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL);
dde->dde_lead_zio[p] = cio;
}
ddt_exit(ddt);
if (cio)
zio_nowait(cio);
if (dio)
zio_nowait(dio);
return (zio);
}
ddt_entry_t *freedde; /* for debugging */
static zio_t *
zio_ddt_free(zio_t *zio)
{
spa_t *spa = zio->io_spa;
blkptr_t *bp = zio->io_bp;
ddt_t *ddt = ddt_select(spa, bp);
ddt_entry_t *dde;
ddt_phys_t *ddp;
ASSERT(BP_GET_DEDUP(bp));
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ddt_enter(ddt);
freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
if (dde) {
ddp = ddt_phys_select(dde, bp);
if (ddp)
ddt_phys_decref(ddp);
}
ddt_exit(ddt);
return (zio);
}
/*
* ==========================================================================
* Allocate and free blocks
* ==========================================================================
*/
static zio_t *
zio_io_to_allocate(spa_t *spa, int allocator)
{
zio_t *zio;
ASSERT(MUTEX_HELD(&spa->spa_alloc_locks[allocator]));
zio = avl_first(&spa->spa_alloc_trees[allocator]);
if (zio == NULL)
return (NULL);
ASSERT(IO_IS_ALLOCATING(zio));
/*
* Try to place a reservation for this zio. If we're unable to
* reserve then we throttle.
*/
ASSERT3U(zio->io_allocator, ==, allocator);
if (!metaslab_class_throttle_reserve(zio->io_metaslab_class,
zio->io_prop.zp_copies, zio->io_allocator, zio, 0)) {
return (NULL);
}
avl_remove(&spa->spa_alloc_trees[allocator], zio);
ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE);
return (zio);
}
static zio_t *
zio_dva_throttle(zio_t *zio)
{
spa_t *spa = zio->io_spa;
zio_t *nio;
metaslab_class_t *mc;
/* locate an appropriate allocation class */
mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type,
zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk);
if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE ||
!mc->mc_alloc_throttle_enabled ||
zio->io_child_type == ZIO_CHILD_GANG ||
zio->io_flags & ZIO_FLAG_NODATA) {
return (zio);
}
ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
ASSERT3U(zio->io_queued_timestamp, >, 0);
ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE);
zbookmark_phys_t *bm = &zio->io_bookmark;
/*
* We want to try to use as many allocators as possible to help improve
* performance, but we also want logically adjacent IOs to be physically
* adjacent to improve sequential read performance. We chunk each object
* into 2^20 block regions, and then hash based on the objset, object,
* level, and region to accomplish both of these goals.
*/
zio->io_allocator = cityhash4(bm->zb_objset, bm->zb_object,
bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count;
mutex_enter(&spa->spa_alloc_locks[zio->io_allocator]);
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
zio->io_metaslab_class = mc;
avl_add(&spa->spa_alloc_trees[zio->io_allocator], zio);
nio = zio_io_to_allocate(spa, zio->io_allocator);
mutex_exit(&spa->spa_alloc_locks[zio->io_allocator]);
return (nio);
}
static void
zio_allocate_dispatch(spa_t *spa, int allocator)
{
zio_t *zio;
mutex_enter(&spa->spa_alloc_locks[allocator]);
zio = zio_io_to_allocate(spa, allocator);
mutex_exit(&spa->spa_alloc_locks[allocator]);
if (zio == NULL)
return;
ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE);
ASSERT0(zio->io_error);
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE);
}
static zio_t *
zio_dva_allocate(zio_t *zio)
{
spa_t *spa = zio->io_spa;
metaslab_class_t *mc;
blkptr_t *bp = zio->io_bp;
int error;
int flags = 0;
if (zio->io_gang_leader == NULL) {
ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
zio->io_gang_leader = zio;
}
ASSERT(BP_IS_HOLE(bp));
ASSERT0(BP_GET_NDVAS(bp));
ASSERT3U(zio->io_prop.zp_copies, >, 0);
ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0;
if (zio->io_flags & ZIO_FLAG_NODATA)
flags |= METASLAB_DONT_THROTTLE;
if (zio->io_flags & ZIO_FLAG_GANG_CHILD)
flags |= METASLAB_GANG_CHILD;
if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE)
flags |= METASLAB_ASYNC_ALLOC;
/*
* if not already chosen, locate an appropriate allocation class
*/
mc = zio->io_metaslab_class;
if (mc == NULL) {
mc = spa_preferred_class(spa, zio->io_size,
zio->io_prop.zp_type, zio->io_prop.zp_level,
zio->io_prop.zp_zpl_smallblk);
zio->io_metaslab_class = mc;
}
error = metaslab_alloc(spa, mc, zio->io_size, bp,
zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
&zio->io_alloc_list, zio, zio->io_allocator);
/*
* Fallback to normal class when an alloc class is full
*/
if (error == ENOSPC && mc != spa_normal_class(spa)) {
/*
* If throttling, transfer reservation over to normal class.
* The io_allocator slot can remain the same even though we
* are switching classes.
*/
if (mc->mc_alloc_throttle_enabled &&
(zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) {
metaslab_class_throttle_unreserve(mc,
zio->io_prop.zp_copies, zio->io_allocator, zio);
zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING;
mc = spa_normal_class(spa);
VERIFY(metaslab_class_throttle_reserve(mc,
zio->io_prop.zp_copies, zio->io_allocator, zio,
flags | METASLAB_MUST_RESERVE));
} else {
mc = spa_normal_class(spa);
}
zio->io_metaslab_class = mc;
error = metaslab_alloc(spa, mc, zio->io_size, bp,
zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
&zio->io_alloc_list, zio, zio->io_allocator);
}
if (error != 0) {
zfs_dbgmsg("%s: metaslab allocation failure: zio %px, "
"size %llu, error %d", spa_name(spa), zio, zio->io_size,
error);
if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE)
return (zio_write_gang_block(zio));
zio->io_error = error;
}
return (zio);
}
static zio_t *
zio_dva_free(zio_t *zio)
{
metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
return (zio);
}
static zio_t *
zio_dva_claim(zio_t *zio)
{
int error;
error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
if (error)
zio->io_error = error;
return (zio);
}
/*
* Undo an allocation. This is used by zio_done() when an I/O fails
* and we want to give back the block we just allocated.
* This handles both normal blocks and gang blocks.
*/
static void
zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
{
ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
ASSERT(zio->io_bp_override == NULL);
if (!BP_IS_HOLE(bp))
metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
if (gn != NULL) {
for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
zio_dva_unallocate(zio, gn->gn_child[g],
&gn->gn_gbh->zg_blkptr[g]);
}
}
}
/*
* Try to allocate an intent log block. Return 0 on success, errno on failure.
*/
int
zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp,
uint64_t size, boolean_t *slog)
{
int error = 1;
zio_alloc_list_t io_alloc_list;
ASSERT(txg > spa_syncing_txg(spa));
metaslab_trace_init(&io_alloc_list);
/*
* Block pointer fields are useful to metaslabs for stats and debugging.
* Fill in the obvious ones before calling into metaslab_alloc().
*/
BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
BP_SET_PSIZE(new_bp, size);
BP_SET_LEVEL(new_bp, 0);
/*
* When allocating a zil block, we don't have information about
* the final destination of the block except the objset it's part
* of, so we just hash the objset ID to pick the allocator to get
* some parallelism.
*/
error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1,
txg, NULL, METASLAB_FASTWRITE, &io_alloc_list, NULL,
cityhash4(0, 0, 0, os->os_dsl_dataset->ds_object) %
spa->spa_alloc_count);
if (error == 0) {
*slog = TRUE;
} else {
error = metaslab_alloc(spa, spa_normal_class(spa), size,
new_bp, 1, txg, NULL, METASLAB_FASTWRITE,
&io_alloc_list, NULL, cityhash4(0, 0, 0,
os->os_dsl_dataset->ds_object) % spa->spa_alloc_count);
if (error == 0)
*slog = FALSE;
}
metaslab_trace_fini(&io_alloc_list);
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,
spa_version(spa) >= SPA_VERSION_SLIM_ZIL
? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
BP_SET_LEVEL(new_bp, 0);
BP_SET_DEDUP(new_bp, 0);
BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
/*
* encrypted blocks will require an IV and salt. We generate
* these now since we will not be rewriting the bp at
* rewrite time.
*/
if (os->os_encrypted) {
uint8_t iv[ZIO_DATA_IV_LEN];
uint8_t salt[ZIO_DATA_SALT_LEN];
BP_SET_CRYPT(new_bp, B_TRUE);
VERIFY0(spa_crypt_get_salt(spa,
dmu_objset_id(os), salt));
VERIFY0(zio_crypt_generate_iv(iv));
zio_crypt_encode_params_bp(new_bp, salt, iv);
}
} else {
zfs_dbgmsg("%s: zil block allocation failure: "
"size %llu, error %d", spa_name(spa), size, error);
}
return (error);
}
/*
* ==========================================================================
* Read and write to physical devices
* ==========================================================================
*/
/*
* Issue an I/O to the underlying vdev. Typically the issue pipeline
* stops after this stage and will resume upon I/O completion.
* However, there are instances where the vdev layer may need to
* continue the pipeline when an I/O was not issued. Since the I/O
* that was sent to the vdev layer might be different than the one
* currently active in the pipeline (see vdev_queue_io()), we explicitly
* force the underlying vdev layers to call either zio_execute() or
* zio_interrupt() to ensure that the pipeline continues with the correct I/O.
*/
static zio_t *
zio_vdev_io_start(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
uint64_t align;
spa_t *spa = zio->io_spa;
zio->io_delay = 0;
ASSERT(zio->io_error == 0);
ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
if (vd == NULL) {
if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
/*
* The mirror_ops handle multiple DVAs in a single BP.
*/
vdev_mirror_ops.vdev_op_io_start(zio);
return (NULL);
}
ASSERT3P(zio->io_logical, !=, zio);
if (zio->io_type == ZIO_TYPE_WRITE) {
ASSERT(spa->spa_trust_config);
/*
* Note: the code can handle other kinds of writes,
* but we don't expect them.
*/
if (zio->io_vd->vdev_removing) {
ASSERT(zio->io_flags &
(ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL |
ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE));
}
}
align = 1ULL << vd->vdev_top->vdev_ashift;
if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) &&
P2PHASE(zio->io_size, align) != 0) {
/* Transform logical writes to be a full physical block size. */
uint64_t asize = P2ROUNDUP(zio->io_size, align);
abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize);
ASSERT(vd == vd->vdev_top);
if (zio->io_type == ZIO_TYPE_WRITE) {
abd_copy(abuf, zio->io_abd, zio->io_size);
abd_zero_off(abuf, zio->io_size, asize - zio->io_size);
}
zio_push_transform(zio, abuf, asize, asize, zio_subblock);
}
/*
* If this is not a physical io, make sure that it is properly aligned
* before proceeding.
*/
if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) {
ASSERT0(P2PHASE(zio->io_offset, align));
ASSERT0(P2PHASE(zio->io_size, align));
} else {
/*
* For physical writes, we allow 512b aligned writes and assume
* the device will perform a read-modify-write as necessary.
*/
ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE));
ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE));
}
VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
/*
* If this is a repair I/O, and there's no self-healing involved --
* that is, we're just resilvering what we expect to resilver --
* then don't do the I/O unless zio's txg is actually in vd's DTL.
* This prevents spurious resilvering.
*
* There are a few ways that we can end up creating these spurious
* resilver i/os:
*
* 1. A resilver i/o will be issued if any DVA in the BP has a
* dirty DTL. The mirror code will issue resilver writes to
* each DVA, including the one(s) that are not on vdevs with dirty
* DTLs.
*
* 2. With nested replication, which happens when we have a
* "replacing" or "spare" vdev that's a child of a mirror or raidz.
* For example, given mirror(replacing(A+B), C), it's likely that
* only A is out of date (it's the new device). In this case, we'll
* read from C, then use the data to resilver A+B -- but we don't
* actually want to resilver B, just A. The top-level mirror has no
* way to know this, so instead we just discard unnecessary repairs
* as we work our way down the vdev tree.
*
* 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc.
* The same logic applies to any form of nested replication: ditto
* + mirror, RAID-Z + replacing, etc.
*
* However, indirect vdevs point off to other vdevs which may have
* DTL's, so we never bypass them. The child i/os on concrete vdevs
* will be properly bypassed instead.
*/
if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
!(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
zio->io_txg != 0 && /* not a delegated i/o */
vd->vdev_ops != &vdev_indirect_ops &&
!vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
zio_vdev_io_bypass(zio);
return (zio);
}
if (vd->vdev_ops->vdev_op_leaf && (zio->io_type == ZIO_TYPE_READ ||
zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM)) {
if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio))
return (zio);
if ((zio = vdev_queue_io(zio)) == NULL)
return (NULL);
if (!vdev_accessible(vd, zio)) {
zio->io_error = SET_ERROR(ENXIO);
zio_interrupt(zio);
return (NULL);
}
zio->io_delay = gethrtime();
}
vd->vdev_ops->vdev_op_io_start(zio);
return (NULL);
}
static zio_t *
zio_vdev_io_done(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
boolean_t unexpected_error = B_FALSE;
if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
return (NULL);
}
ASSERT(zio->io_type == ZIO_TYPE_READ ||
zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM);
if (zio->io_delay)
zio->io_delay = gethrtime() - zio->io_delay;
if (vd != NULL && vd->vdev_ops->vdev_op_leaf) {
vdev_queue_io_done(zio);
if (zio->io_type == ZIO_TYPE_WRITE)
vdev_cache_write(zio);
if (zio_injection_enabled && zio->io_error == 0)
zio->io_error = zio_handle_device_injections(vd, zio,
EIO, EILSEQ);
if (zio_injection_enabled && zio->io_error == 0)
zio->io_error = zio_handle_label_injection(zio, EIO);
if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) {
if (!vdev_accessible(vd, zio)) {
zio->io_error = SET_ERROR(ENXIO);
} else {
unexpected_error = B_TRUE;
}
}
}
ops->vdev_op_io_done(zio);
if (unexpected_error)
VERIFY(vdev_probe(vd, zio) == NULL);
return (zio);
}
/*
* This function is used to change the priority of an existing zio that is
* currently in-flight. This is used by the arc to upgrade priority in the
* event that a demand read is made for a block that is currently queued
* as a scrub or async read IO. Otherwise, the high priority read request
* would end up having to wait for the lower priority IO.
*/
void
zio_change_priority(zio_t *pio, zio_priority_t priority)
{
zio_t *cio, *cio_next;
zio_link_t *zl = NULL;
ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);
if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) {
vdev_queue_change_io_priority(pio, priority);
} else {
pio->io_priority = priority;
}
mutex_enter(&pio->io_lock);
for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
cio_next = zio_walk_children(pio, &zl);
zio_change_priority(cio, priority);
}
mutex_exit(&pio->io_lock);
}
/*
* For non-raidz ZIOs, we can just copy aside the bad data read from the
* disk, and use that to finish the checksum ereport later.
*/
static void
zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
const abd_t *good_buf)
{
/* no processing needed */
zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
}
/*ARGSUSED*/
void
zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored)
{
void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size);
abd_copy(abd, zio->io_abd, zio->io_size);
zcr->zcr_cbinfo = zio->io_size;
zcr->zcr_cbdata = abd;
zcr->zcr_finish = zio_vsd_default_cksum_finish;
zcr->zcr_free = zio_abd_free;
}
static zio_t *
zio_vdev_io_assess(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
return (NULL);
}
if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
spa_config_exit(zio->io_spa, SCL_ZIO, zio);
if (zio->io_vsd != NULL) {
zio->io_vsd_ops->vsd_free(zio);
zio->io_vsd = NULL;
}
if (zio_injection_enabled && zio->io_error == 0)
zio->io_error = zio_handle_fault_injection(zio, EIO);
/*
* If the I/O failed, determine whether we should attempt to retry it.
*
* On retry, we cut in line in the issue queue, since we don't want
* compression/checksumming/etc. work to prevent our (cheap) IO reissue.
*/
if (zio->io_error && vd == NULL &&
!(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */
zio->io_error = 0;
zio->io_flags |= ZIO_FLAG_IO_RETRY |
ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
zio_requeue_io_start_cut_in_line);
return (NULL);
}
/*
* If we got an error on a leaf device, convert it to ENXIO
* if the device is not accessible at all.
*/
if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
!vdev_accessible(vd, zio))
zio->io_error = SET_ERROR(ENXIO);
/*
* If we can't write to an interior vdev (mirror or RAID-Z),
* set vdev_cant_write so that we stop trying to allocate from it.
*/
if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
vd != NULL && !vd->vdev_ops->vdev_op_leaf) {
vd->vdev_cant_write = B_TRUE;
}
/*
* If a cache flush returns ENOTSUP or ENOTTY, we know that no future
* attempts will ever succeed. In this case we set a persistent
* boolean flag so that we don't bother with it in the future.
*/
if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) &&
zio->io_type == ZIO_TYPE_IOCTL &&
zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL)
vd->vdev_nowritecache = B_TRUE;
if (zio->io_error)
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
zio->io_physdone != NULL) {
ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED));
ASSERT(zio->io_child_type == ZIO_CHILD_VDEV);
zio->io_physdone(zio->io_logical);
}
return (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 >>= 1;
}
void
zio_vdev_io_redone(zio_t *zio)
{
ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
zio->io_stage >>= 1;
}
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;
}
/*
* ==========================================================================
* Encrypt and store encryption parameters
* ==========================================================================
*/
/*
* This function is used for ZIO_STAGE_ENCRYPT. It is responsible for
* managing the storage of encryption parameters and passing them to the
* lower-level encryption functions.
*/
static zio_t *
zio_encrypt(zio_t *zio)
{
zio_prop_t *zp = &zio->io_prop;
spa_t *spa = zio->io_spa;
blkptr_t *bp = zio->io_bp;
uint64_t psize = BP_GET_PSIZE(bp);
uint64_t dsobj = zio->io_bookmark.zb_objset;
dmu_object_type_t ot = BP_GET_TYPE(bp);
void *enc_buf = NULL;
abd_t *eabd = NULL;
uint8_t salt[ZIO_DATA_SALT_LEN];
uint8_t iv[ZIO_DATA_IV_LEN];
uint8_t mac[ZIO_DATA_MAC_LEN];
boolean_t no_crypt = B_FALSE;
/* the root zio already encrypted the data */
if (zio->io_child_type == ZIO_CHILD_GANG)
return (zio);
/* only ZIL blocks are re-encrypted on rewrite */
if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG)
return (zio);
if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) {
BP_SET_CRYPT(bp, B_FALSE);
return (zio);
}
/* if we are doing raw encryption set the provided encryption params */
if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) {
ASSERT0(BP_GET_LEVEL(bp));
BP_SET_CRYPT(bp, B_TRUE);
BP_SET_BYTEORDER(bp, zp->zp_byteorder);
if (ot != DMU_OT_OBJSET)
zio_crypt_encode_mac_bp(bp, zp->zp_mac);
/* dnode blocks must be written out in the provided byteorder */
if (zp->zp_byteorder != ZFS_HOST_BYTEORDER &&
ot == DMU_OT_DNODE) {
void *bswap_buf = zio_buf_alloc(psize);
abd_t *babd = abd_get_from_buf(bswap_buf, psize);
ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
abd_copy_to_buf(bswap_buf, zio->io_abd, psize);
dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf,
psize);
abd_take_ownership_of_buf(babd, B_TRUE);
zio_push_transform(zio, babd, psize, psize, NULL);
}
if (DMU_OT_IS_ENCRYPTED(ot))
zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv);
return (zio);
}
/* indirect blocks only maintain a cksum of the lower level MACs */
if (BP_GET_LEVEL(bp) > 0) {
BP_SET_CRYPT(bp, B_TRUE);
VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE,
zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp),
mac));
zio_crypt_encode_mac_bp(bp, mac);
return (zio);
}
/*
* Objset blocks are a special case since they have 2 256-bit MACs
* embedded within them.
*/
if (ot == DMU_OT_OBJSET) {
ASSERT0(DMU_OT_IS_ENCRYPTED(ot));
ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
BP_SET_CRYPT(bp, B_TRUE);
VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj,
zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp)));
return (zio);
}
/* unencrypted object types are only authenticated with a MAC */
if (!DMU_OT_IS_ENCRYPTED(ot)) {
BP_SET_CRYPT(bp, B_TRUE);
VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj,
zio->io_abd, psize, mac));
zio_crypt_encode_mac_bp(bp, mac);
return (zio);
}
/*
* Later passes of sync-to-convergence may decide to rewrite data
* in place to avoid more disk reallocations. This presents a problem
* for encryption because this constitutes rewriting the new data with
* the same encryption key and IV. However, this only applies to blocks
* in the MOS (particularly the spacemaps) and we do not encrypt the
* MOS. We assert that the zio is allocating or an intent log write
* to enforce this.
*/
ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG);
ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG);
ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION));
ASSERT3U(psize, !=, 0);
enc_buf = zio_buf_alloc(psize);
eabd = abd_get_from_buf(enc_buf, psize);
abd_take_ownership_of_buf(eabd, B_TRUE);
/*
* For an explanation of what encryption parameters are stored
* where, see the block comment in zio_crypt.c.
*/
if (ot == DMU_OT_INTENT_LOG) {
zio_crypt_decode_params_bp(bp, salt, iv);
} else {
BP_SET_CRYPT(bp, B_TRUE);
}
/* Perform the encryption. This should not fail */
VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark,
BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp),
salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt));
/* encode encryption metadata into the bp */
if (ot == DMU_OT_INTENT_LOG) {
/*
* ZIL blocks store the MAC in the embedded checksum, so the
* transform must always be applied.
*/
zio_crypt_encode_mac_zil(enc_buf, mac);
zio_push_transform(zio, eabd, psize, psize, NULL);
} else {
BP_SET_CRYPT(bp, B_TRUE);
zio_crypt_encode_params_bp(bp, salt, iv);
zio_crypt_encode_mac_bp(bp, mac);
if (no_crypt) {
ASSERT3U(ot, ==, DMU_OT_DNODE);
abd_free(eabd);
} else {
zio_push_transform(zio, eabd, psize, psize, NULL);
}
}
return (zio);
}
/*
* ==========================================================================
* Generate and verify checksums
* ==========================================================================
*/
static zio_t *
zio_checksum_generate(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
enum zio_checksum checksum;
if (bp == NULL) {
/*
* This is zio_write_phys().
* We're either generating a label checksum, or none at all.
*/
checksum = zio->io_prop.zp_checksum;
if (checksum == ZIO_CHECKSUM_OFF)
return (zio);
ASSERT(checksum == ZIO_CHECKSUM_LABEL);
} else {
if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
ASSERT(!IO_IS_ALLOCATING(zio));
checksum = ZIO_CHECKSUM_GANG_HEADER;
} else {
checksum = BP_GET_CHECKSUM(bp);
}
}
zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size);
return (zio);
}
static zio_t *
zio_checksum_verify(zio_t *zio)
{
zio_bad_cksum_t info;
blkptr_t *bp = zio->io_bp;
int error;
ASSERT(zio->io_vd != NULL);
if (bp == NULL) {
/*
* This is zio_read_phys().
* We're either verifying a label checksum, or nothing at all.
*/
if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
return (zio);
ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL);
}
if ((error = zio_checksum_error(zio, &info)) != 0) {
zio->io_error = error;
if (error == ECKSUM &&
!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
mutex_enter(&zio->io_vd->vdev_stat_lock);
zio->io_vd->vdev_stat.vs_checksum_errors++;
mutex_exit(&zio->io_vd->vdev_stat_lock);
zfs_ereport_start_checksum(zio->io_spa,
zio->io_vd, &zio->io_bookmark, zio,
zio->io_offset, zio->io_size, NULL, &info);
}
}
return (zio);
}
/*
* Called by RAID-Z to ensure we don't compute the checksum twice.
*/
void
zio_checksum_verified(zio_t *zio)
{
zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
}
/*
* ==========================================================================
* Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
* An error of 0 indicates success. ENXIO indicates whole-device failure,
* which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO
* indicate errors that are specific to one I/O, and most likely permanent.
* Any other error is presumed to be worse because we weren't expecting it.
* ==========================================================================
*/
int
zio_worst_error(int e1, int e2)
{
static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
int r1, r2;
for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
if (e1 == zio_error_rank[r1])
break;
for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
if (e2 == zio_error_rank[r2])
break;
return (r1 > r2 ? e1 : e2);
}
/*
* ==========================================================================
* I/O completion
* ==========================================================================
*/
static zio_t *
zio_ready(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
zio_t *pio, *pio_next;
zio_link_t *zl = NULL;
if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT,
ZIO_WAIT_READY)) {
return (NULL);
}
if (zio->io_ready) {
ASSERT(IO_IS_ALLOCATING(zio));
ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
(zio->io_flags & ZIO_FLAG_NOPWRITE));
ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
zio->io_ready(zio);
}
if (bp != NULL && bp != &zio->io_bp_copy)
zio->io_bp_copy = *bp;
if (zio->io_error != 0) {
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
ASSERT(IO_IS_ALLOCATING(zio));
ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(zio->io_metaslab_class != NULL);
/*
* We were unable to allocate anything, unreserve and
* issue the next I/O to allocate.
*/
metaslab_class_throttle_unreserve(
zio->io_metaslab_class, zio->io_prop.zp_copies,
zio->io_allocator, zio);
zio_allocate_dispatch(zio->io_spa, zio->io_allocator);
}
}
mutex_enter(&zio->io_lock);
zio->io_state[ZIO_WAIT_READY] = 1;
pio = zio_walk_parents(zio, &zl);
mutex_exit(&zio->io_lock);
/*
* As we notify zio's parents, new parents could be added.
* New parents go to the head of zio's io_parent_list, however,
* so we will (correctly) not notify them. The remainder of zio's
* io_parent_list, from 'pio_next' onward, cannot change because
* all parents must wait for us to be done before they can be done.
*/
for (; pio != NULL; pio = pio_next) {
pio_next = zio_walk_parents(zio, &zl);
zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL);
}
if (zio->io_flags & ZIO_FLAG_NODATA) {
if (BP_IS_GANG(bp)) {
zio->io_flags &= ~ZIO_FLAG_NODATA;
} else {
ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE);
zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
}
}
if (zio_injection_enabled &&
zio->io_spa->spa_syncing_txg == zio->io_txg)
zio_handle_ignored_writes(zio);
return (zio);
}
/*
* Update the allocation throttle accounting.
*/
static void
zio_dva_throttle_done(zio_t *zio)
{
ASSERTV(zio_t *lio = zio->io_logical);
zio_t *pio = zio_unique_parent(zio);
vdev_t *vd = zio->io_vd;
int flags = METASLAB_ASYNC_ALLOC;
ASSERT3P(zio->io_bp, !=, NULL);
ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE);
ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
ASSERT(vd != NULL);
ASSERT3P(vd, ==, vd->vdev_top);
ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY));
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING);
ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE));
ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA));
/*
* Parents of gang children can have two flavors -- ones that
* allocated the gang header (will have ZIO_FLAG_IO_REWRITE set)
* and ones that allocated the constituent blocks. The allocation
* throttle needs to know the allocating parent zio so we must find
* it here.
*/
if (pio->io_child_type == ZIO_CHILD_GANG) {
/*
* If our parent is a rewrite gang child then our grandparent
* would have been the one that performed the allocation.
*/
if (pio->io_flags & ZIO_FLAG_IO_REWRITE)
pio = zio_unique_parent(pio);
flags |= METASLAB_GANG_CHILD;
}
ASSERT(IO_IS_ALLOCATING(pio));
ASSERT3P(zio, !=, zio->io_logical);
ASSERT(zio->io_logical != NULL);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE);
ASSERT(zio->io_metaslab_class != NULL);
mutex_enter(&pio->io_lock);
metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags,
pio->io_allocator, B_TRUE);
mutex_exit(&pio->io_lock);
metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1,
pio->io_allocator, pio);
/*
* Call into the pipeline to see if there is more work that
* needs to be done. If there is work to be done it will be
* dispatched to another taskq thread.
*/
zio_allocate_dispatch(zio->io_spa, pio->io_allocator);
}
static zio_t *
zio_done(zio_t *zio)
{
/*
* Always attempt to keep stack usage minimal here since
* we can be called recursively up to 19 levels deep.
*/
const uint64_t psize = zio->io_size;
zio_t *pio, *pio_next;
zio_link_t *zl = NULL;
/*
* If our children haven't all completed,
* wait for them and then repeat this pipeline stage.
*/
if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) {
return (NULL);
}
/*
* If the allocation throttle is enabled, then update the accounting.
* We only track child I/Os that are part of an allocating async
* write. We must do this since the allocation is performed
* by the logical I/O but the actual write is done by child I/Os.
*/
if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING &&
zio->io_child_type == ZIO_CHILD_VDEV) {
ASSERT(zio->io_metaslab_class != NULL);
ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled);
zio_dva_throttle_done(zio);
}
/*
* If the allocation throttle is enabled, verify that
* we have decremented the refcounts for every I/O that was throttled.
*/
if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
ASSERT(zio->io_bp != NULL);
metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio,
zio->io_allocator);
VERIFY(zfs_refcount_not_held(
&zio->io_metaslab_class->mc_alloc_slots[zio->io_allocator],
zio));
}
for (int c = 0; c < ZIO_CHILD_TYPES; c++)
for (int w = 0; w < ZIO_WAIT_TYPES; w++)
ASSERT(zio->io_children[c][w] == 0);
if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) {
ASSERT(zio->io_bp->blk_pad[0] == 0);
ASSERT(zio->io_bp->blk_pad[1] == 0);
ASSERT(bcmp(zio->io_bp, &zio->io_bp_copy,
sizeof (blkptr_t)) == 0 ||
(zio->io_bp == zio_unique_parent(zio)->io_bp));
if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) &&
zio->io_bp_override == NULL &&
!(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
ASSERT3U(zio->io_prop.zp_copies, <=,
BP_GET_NDVAS(zio->io_bp));
ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 ||
(BP_COUNT_GANG(zio->io_bp) ==
BP_GET_NDVAS(zio->io_bp)));
}
if (zio->io_flags & ZIO_FLAG_NOPWRITE)
VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig));
}
/*
* If there were child vdev/gang/ddt errors, they apply to us now.
*/
zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
/*
* If the I/O on the transformed data was successful, generate any
* checksum reports now while we still have the transformed data.
*/
if (zio->io_error == 0) {
while (zio->io_cksum_report != NULL) {
zio_cksum_report_t *zcr = zio->io_cksum_report;
uint64_t align = zcr->zcr_align;
uint64_t asize = P2ROUNDUP(psize, align);
abd_t *adata = zio->io_abd;
if (asize != psize) {
adata = abd_alloc(asize, B_TRUE);
abd_copy(adata, zio->io_abd, psize);
abd_zero_off(adata, psize, asize - psize);
}
zio->io_cksum_report = zcr->zcr_next;
zcr->zcr_next = NULL;
zcr->zcr_finish(zcr, adata);
zfs_ereport_free_checksum(zcr);
if (asize != psize)
abd_free(adata);
}
}
zio_pop_transforms(zio); /* note: may set zio->io_error */
vdev_stat_update(zio, psize);
/*
* If this I/O is attached to a particular vdev is slow, exceeding
* 30 seconds to complete, post an error described the I/O delay.
* We ignore these errors if the device is currently unavailable.
*/
if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) {
if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) {
/*
* We want to only increment our slow IO counters if
* the IO is valid (i.e. not if the drive is removed).
*
* zfs_ereport_post() will also do these checks, but
* it can also ratelimit and have other failures, so we
* need to increment the slow_io counters independent
* of it.
*/
if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY,
zio->io_spa, zio->io_vd, zio)) {
mutex_enter(&zio->io_vd->vdev_stat_lock);
zio->io_vd->vdev_stat.vs_slow_ios++;
mutex_exit(&zio->io_vd->vdev_stat_lock);
zfs_ereport_post(FM_EREPORT_ZFS_DELAY,
zio->io_spa, zio->io_vd, &zio->io_bookmark,
zio, 0, 0);
}
}
}
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 && zio->io_vd != NULL &&
!vdev_is_dead(zio->io_vd)) {
mutex_enter(&zio->io_vd->vdev_stat_lock);
if (zio->io_type == ZIO_TYPE_READ) {
zio->io_vd->vdev_stat.vs_read_errors++;
} else if (zio->io_type == ZIO_TYPE_WRITE) {
zio->io_vd->vdev_stat.vs_write_errors++;
}
mutex_exit(&zio->io_vd->vdev_stat_lock);
zfs_ereport_post(FM_EREPORT_ZFS_IO, zio->io_spa,
zio->io_vd, &zio->io_bookmark, zio, 0, 0);
}
if ((zio->io_error == EIO || !(zio->io_flags &
(ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
zio == zio->io_logical) {
/*
* For logical I/O requests, tell the SPA to log the
* error and generate a logical data ereport.
*/
spa_log_error(zio->io_spa, &zio->io_bookmark);
zfs_ereport_post(FM_EREPORT_ZFS_DATA, zio->io_spa,
NULL, &zio->io_bookmark, zio, 0, 0);
}
}
if (zio->io_error && zio == zio->io_logical) {
/*
* Determine whether zio should be reexecuted. This will
* propagate all the way to the root via zio_notify_parent().
*/
ASSERT(zio->io_vd == NULL && zio->io_bp != NULL);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
if (IO_IS_ALLOCATING(zio) &&
!(zio->io_flags & ZIO_FLAG_CANFAIL)) {
if (zio->io_error != ENOSPC)
zio->io_reexecute |= ZIO_REEXECUTE_NOW;
else
zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
}
if ((zio->io_type == ZIO_TYPE_READ ||
zio->io_type == ZIO_TYPE_FREE) &&
!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
zio->io_error == ENXIO &&
spa_load_state(zio->io_spa) == SPA_LOAD_NONE &&
spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE)
zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
/*
* Here is a possibly good place to attempt to do
* either combinatorial reconstruction or error correction
* based on checksums. It also might be a good place
* to send out preliminary ereports before we suspend
* processing.
*/
}
/*
* If there were logical child errors, they apply to us now.
* We defer this until now to avoid conflating logical child
* errors with errors that happened to the zio itself when
* updating vdev stats and reporting FMA events above.
*/
zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
if ((zio->io_error || zio->io_reexecute) &&
IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
!(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp);
zio_gang_tree_free(&zio->io_gang_tree);
/*
* Godfather I/Os should never suspend.
*/
if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
(zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND;
if (zio->io_reexecute) {
/*
* This is a logical I/O that wants to reexecute.
*
* Reexecute is top-down. When an i/o fails, if it's not
* the root, it simply notifies its parent and sticks around.
* The parent, seeing that it still has children in zio_done(),
* does the same. This percolates all the way up to the root.
* The root i/o will reexecute or suspend the entire tree.
*
* This approach ensures that zio_reexecute() honors
* all the original i/o dependency relationships, e.g.
* parents not executing until children are ready.
*/
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
zio->io_gang_leader = NULL;
mutex_enter(&zio->io_lock);
zio->io_state[ZIO_WAIT_DONE] = 1;
mutex_exit(&zio->io_lock);
/*
* "The Godfather" I/O monitors its children but is
* not a true parent to them. It will track them through
* the pipeline but severs its ties whenever they get into
* trouble (e.g. suspended). This allows "The Godfather"
* I/O to return status without blocking.
*/
zl = NULL;
for (pio = zio_walk_parents(zio, &zl); pio != NULL;
pio = pio_next) {
zio_link_t *remove_zl = zl;
pio_next = zio_walk_parents(zio, &zl);
if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
(zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
zio_remove_child(pio, zio, remove_zl);
/*
* This is a rare code path, so we don't
* bother with "next_to_execute".
*/
zio_notify_parent(pio, zio, ZIO_WAIT_DONE,
NULL);
}
}
if ((pio = zio_unique_parent(zio)) != NULL) {
/*
* We're not a root i/o, so there's nothing to do
* but notify our parent. Don't propagate errors
* upward since we haven't permanently failed yet.
*/
ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
/*
* This is a rare code path, so we don't bother with
* "next_to_execute".
*/
zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL);
} else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
/*
* We'd fail again if we reexecuted now, so suspend
* until conditions improve (e.g. device comes online).
*/
zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR);
} else {
/*
* Reexecution is potentially a huge amount of work.
* Hand it off to the otherwise-unused claim taskq.
*/
ASSERT(taskq_empty_ent(&zio->io_tqent));
spa_taskq_dispatch_ent(zio->io_spa,
ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE,
(task_func_t *)zio_reexecute, zio, 0,
&zio->io_tqent);
}
return (NULL);
}
ASSERT(zio->io_child_count == 0);
ASSERT(zio->io_reexecute == 0);
ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
/*
* Report any checksum errors, since the I/O is complete.
*/
while (zio->io_cksum_report != NULL) {
zio_cksum_report_t *zcr = zio->io_cksum_report;
zio->io_cksum_report = zcr->zcr_next;
zcr->zcr_next = NULL;
zcr->zcr_finish(zcr, NULL);
zfs_ereport_free_checksum(zcr);
}
if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp &&
!BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) &&
!(zio->io_flags & ZIO_FLAG_NOPWRITE)) {
metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp);
}
/*
* It is the responsibility of the done callback to ensure that this
* particular zio is no longer discoverable for adoption, and as
* such, cannot acquire any new parents.
*/
if (zio->io_done)
zio->io_done(zio);
mutex_enter(&zio->io_lock);
zio->io_state[ZIO_WAIT_DONE] = 1;
mutex_exit(&zio->io_lock);
/*
* We are done executing this zio. We may want to execute a parent
* next. See the comment in zio_notify_parent().
*/
zio_t *next_to_execute = NULL;
zl = NULL;
for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) {
zio_link_t *remove_zl = zl;
pio_next = zio_walk_parents(zio, &zl);
zio_remove_child(pio, zio, remove_zl);
zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute);
}
if (zio->io_waiter != NULL) {
mutex_enter(&zio->io_lock);
zio->io_executor = NULL;
cv_broadcast(&zio->io_cv);
mutex_exit(&zio->io_lock);
} else {
zio_destroy(zio);
}
return (next_to_execute);
}
/*
* ==========================================================================
* I/O pipeline definition
* ==========================================================================
*/
static zio_pipe_stage_t *zio_pipeline[] = {
NULL,
zio_read_bp_init,
zio_write_bp_init,
zio_free_bp_init,
zio_issue_async,
zio_write_compress,
zio_encrypt,
zio_checksum_generate,
zio_nop_write,
zio_ddt_read_start,
zio_ddt_read_done,
zio_ddt_write,
zio_ddt_free,
zio_gang_assemble,
zio_gang_issue,
zio_dva_throttle,
zio_dva_allocate,
zio_dva_free,
zio_dva_claim,
zio_ready,
zio_vdev_io_start,
zio_vdev_io_done,
zio_vdev_io_assess,
zio_checksum_verify,
zio_done
};
/*
* Compare two zbookmark_phys_t's to see which we would reach first in a
* pre-order traversal of the object tree.
*
* This is simple in every case aside from the meta-dnode object. For all other
* objects, we traverse them in order (object 1 before object 2, and so on).
* However, all of these objects are traversed while traversing object 0, since
* the data it points to is the list of objects. Thus, we need to convert to a
* canonical representation so we can compare meta-dnode bookmarks to
* non-meta-dnode bookmarks.
*
* We do this by calculating "equivalents" for each field of the zbookmark.
* zbookmarks outside of the meta-dnode use their own object and level, and
* calculate the level 0 equivalent (the first L0 blkid that is contained in the
* blocks this bookmark refers to) by multiplying their blkid by their span
* (the number of L0 blocks contained within one block at their level).
* zbookmarks inside the meta-dnode calculate their object equivalent
* (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use
* level + 1<<31 (any value larger than a level could ever be) for their level.
* This causes them to always compare before a bookmark in their object
* equivalent, compare appropriately to bookmarks in other objects, and to
* compare appropriately to other bookmarks in the meta-dnode.
*/
int
zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2,
const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2)
{
/*
* These variables represent the "equivalent" values for the zbookmark,
* after converting zbookmarks inside the meta dnode to their
* normal-object equivalents.
*/
uint64_t zb1obj, zb2obj;
uint64_t zb1L0, zb2L0;
uint64_t zb1level, zb2level;
if (zb1->zb_object == zb2->zb_object &&
zb1->zb_level == zb2->zb_level &&
zb1->zb_blkid == zb2->zb_blkid)
return (0);
/*
* BP_SPANB calculates the span in blocks.
*/
zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level);
zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level);
if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
zb1L0 = 0;
zb1level = zb1->zb_level + COMPARE_META_LEVEL;
} else {
zb1obj = zb1->zb_object;
zb1level = zb1->zb_level;
}
if (zb2->zb_object == DMU_META_DNODE_OBJECT) {
zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
zb2L0 = 0;
zb2level = zb2->zb_level + COMPARE_META_LEVEL;
} else {
zb2obj = zb2->zb_object;
zb2level = zb2->zb_level;
}
/* Now that we have a canonical representation, do the comparison. */
if (zb1obj != zb2obj)
return (zb1obj < zb2obj ? -1 : 1);
else if (zb1L0 != zb2L0)
return (zb1L0 < zb2L0 ? -1 : 1);
else if (zb1level != zb2level)
return (zb1level > zb2level ? -1 : 1);
/*
* This can (theoretically) happen if the bookmarks have the same object
* and level, but different blkids, if the block sizes are not the same.
* There is presently no way to change the indirect block sizes
*/
return (0);
}
/*
* This function checks the following: given that last_block is the place that
* our traversal stopped last time, does that guarantee that we've visited
* every node under subtree_root? Therefore, we can't just use the raw output
* of zbookmark_compare. We have to pass in a modified version of
* subtree_root; by incrementing the block id, and then checking whether
* last_block is before or equal to that, we can tell whether or not having
* visited last_block implies that all of subtree_root's children have been
* visited.
*/
boolean_t
zbookmark_subtree_completed(const dnode_phys_t *dnp,
const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block)
{
zbookmark_phys_t mod_zb = *subtree_root;
mod_zb.zb_blkid++;
ASSERT(last_block->zb_level == 0);
/* The objset_phys_t isn't before anything. */
if (dnp == NULL)
return (B_FALSE);
/*
* We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the
* data block size in sectors, because that variable is only used if
* the bookmark refers to a block in the meta-dnode. Since we don't
* know without examining it what object it refers to, and there's no
* harm in passing in this value in other cases, we always pass it in.
*
* We pass in 0 for the indirect block size shift because zb2 must be
* level 0. The indirect block size is only used to calculate the span
* of the bookmark, but since the bookmark must be level 0, the span is
* always 1, so the math works out.
*
* If you make changes to how the zbookmark_compare code works, be sure
* to make sure that this code still works afterwards.
*/
return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift,
1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb,
last_block) <= 0);
}
#if defined(_KERNEL)
EXPORT_SYMBOL(zio_type_name);
EXPORT_SYMBOL(zio_buf_alloc);
EXPORT_SYMBOL(zio_data_buf_alloc);
EXPORT_SYMBOL(zio_buf_free);
EXPORT_SYMBOL(zio_data_buf_free);
module_param(zio_slow_io_ms, int, 0644);
MODULE_PARM_DESC(zio_slow_io_ms,
"Max I/O completion time (milliseconds) before marking it as slow");
module_param(zio_requeue_io_start_cut_in_line, int, 0644);
MODULE_PARM_DESC(zio_requeue_io_start_cut_in_line, "Prioritize requeued I/O");
module_param(zfs_sync_pass_deferred_free, int, 0644);
MODULE_PARM_DESC(zfs_sync_pass_deferred_free,
"Defer frees starting in this pass");
module_param(zfs_sync_pass_dont_compress, int, 0644);
MODULE_PARM_DESC(zfs_sync_pass_dont_compress,
"Don't compress starting in this pass");
module_param(zfs_sync_pass_rewrite, int, 0644);
MODULE_PARM_DESC(zfs_sync_pass_rewrite,
"Rewrite new bps starting in this pass");
module_param(zio_dva_throttle_enabled, int, 0644);
MODULE_PARM_DESC(zio_dva_throttle_enabled,
"Throttle block allocations in the ZIO pipeline");
module_param(zio_deadman_log_all, int, 0644);
MODULE_PARM_DESC(zio_deadman_log_all,
"Log all slow ZIOs, not just those with vdevs");
#endif
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