zfs/module/zfs/zil.c

1676 lines
43 KiB
C

/*
* 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 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/dmu.h>
#include <sys/zap.h>
#include <sys/arc.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/dsl_dataset.h>
#include <sys/vdev.h>
#include <sys/dmu_tx.h>
/*
* The zfs intent log (ZIL) saves transaction records of system calls
* that change the file system in memory with enough information
* to be able to replay them. These are stored in memory until
* either the DMU transaction group (txg) commits them to the stable pool
* and they can be discarded, or they are flushed to the stable log
* (also in the pool) due to a fsync, O_DSYNC or other synchronous
* requirement. In the event of a panic or power fail then those log
* records (transactions) are replayed.
*
* There is one ZIL per file system. Its on-disk (pool) format consists
* of 3 parts:
*
* - ZIL header
* - ZIL blocks
* - ZIL records
*
* A log record holds a system call transaction. Log blocks can
* hold many log records and the blocks are chained together.
* Each ZIL block contains a block pointer (blkptr_t) to the next
* ZIL block in the chain. The ZIL header points to the first
* block in the chain. Note there is not a fixed place in the pool
* to hold blocks. They are dynamically allocated and freed as
* needed from the blocks available. Figure X shows the ZIL structure:
*/
/*
* This global ZIL switch affects all pools
*/
int zil_disable = 0; /* disable intent logging */
/*
* Tunable parameter for debugging or performance analysis. Setting
* zfs_nocacheflush will cause corruption on power loss if a volatile
* out-of-order write cache is enabled.
*/
boolean_t zfs_nocacheflush = B_FALSE;
static kmem_cache_t *zil_lwb_cache;
static int
zil_dva_compare(const void *x1, const void *x2)
{
const dva_t *dva1 = x1;
const dva_t *dva2 = x2;
if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2))
return (-1);
if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2))
return (1);
if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2))
return (-1);
if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2))
return (1);
return (0);
}
static void
zil_dva_tree_init(avl_tree_t *t)
{
avl_create(t, zil_dva_compare, sizeof (zil_dva_node_t),
offsetof(zil_dva_node_t, zn_node));
}
static void
zil_dva_tree_fini(avl_tree_t *t)
{
zil_dva_node_t *zn;
void *cookie = NULL;
while ((zn = avl_destroy_nodes(t, &cookie)) != NULL)
kmem_free(zn, sizeof (zil_dva_node_t));
avl_destroy(t);
}
static int
zil_dva_tree_add(avl_tree_t *t, dva_t *dva)
{
zil_dva_node_t *zn;
avl_index_t where;
if (avl_find(t, dva, &where) != NULL)
return (EEXIST);
zn = kmem_alloc(sizeof (zil_dva_node_t), KM_SLEEP);
zn->zn_dva = *dva;
avl_insert(t, zn, where);
return (0);
}
static zil_header_t *
zil_header_in_syncing_context(zilog_t *zilog)
{
return ((zil_header_t *)zilog->zl_header);
}
static void
zil_init_log_chain(zilog_t *zilog, blkptr_t *bp)
{
zio_cksum_t *zc = &bp->blk_cksum;
zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL);
zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL);
zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os);
zc->zc_word[ZIL_ZC_SEQ] = 1ULL;
}
/*
* Read a log block, make sure it's valid, and byteswap it if necessary.
*/
static int
zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, arc_buf_t **abufpp)
{
blkptr_t blk = *bp;
zbookmark_t zb;
uint32_t aflags = ARC_WAIT;
int error;
zb.zb_objset = bp->blk_cksum.zc_word[ZIL_ZC_OBJSET];
zb.zb_object = 0;
zb.zb_level = -1;
zb.zb_blkid = bp->blk_cksum.zc_word[ZIL_ZC_SEQ];
*abufpp = NULL;
/*
* We shouldn't be doing any scrubbing while we're doing log
* replay, it's OK to not lock.
*/
error = arc_read_nolock(NULL, zilog->zl_spa, &blk,
arc_getbuf_func, abufpp, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL |
ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB, &aflags, &zb);
if (error == 0) {
char *data = (*abufpp)->b_data;
uint64_t blksz = BP_GET_LSIZE(bp);
zil_trailer_t *ztp = (zil_trailer_t *)(data + blksz) - 1;
zio_cksum_t cksum = bp->blk_cksum;
/*
* Validate the checksummed log block.
*
* Sequence numbers should be... sequential. The checksum
* verifier for the next block should be bp's checksum plus 1.
*
* Also check the log chain linkage and size used.
*/
cksum.zc_word[ZIL_ZC_SEQ]++;
if (bcmp(&cksum, &ztp->zit_next_blk.blk_cksum,
sizeof (cksum)) || BP_IS_HOLE(&ztp->zit_next_blk) ||
(ztp->zit_nused > (blksz - sizeof (zil_trailer_t)))) {
error = ECKSUM;
}
if (error) {
VERIFY(arc_buf_remove_ref(*abufpp, abufpp) == 1);
*abufpp = NULL;
}
}
dprintf("error %d on %llu:%llu\n", error, zb.zb_objset, zb.zb_blkid);
return (error);
}
/*
* Parse the intent log, and call parse_func for each valid record within.
* Return the highest sequence number.
*/
uint64_t
zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
{
const zil_header_t *zh = zilog->zl_header;
uint64_t claim_seq = zh->zh_claim_seq;
uint64_t seq = 0;
uint64_t max_seq = 0;
blkptr_t blk = zh->zh_log;
arc_buf_t *abuf;
char *lrbuf, *lrp;
zil_trailer_t *ztp;
int reclen, error;
if (BP_IS_HOLE(&blk))
return (max_seq);
/*
* Starting at the block pointed to by zh_log we read the log chain.
* For each block in the chain we strongly check that block to
* ensure its validity. We stop when an invalid block is found.
* For each block pointer in the chain we call parse_blk_func().
* For each record in each valid block we call parse_lr_func().
* If the log has been claimed, stop if we encounter a sequence
* number greater than the highest claimed sequence number.
*/
zil_dva_tree_init(&zilog->zl_dva_tree);
for (;;) {
seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
if (claim_seq != 0 && seq > claim_seq)
break;
ASSERT(max_seq < seq);
max_seq = seq;
error = zil_read_log_block(zilog, &blk, &abuf);
if (parse_blk_func != NULL)
parse_blk_func(zilog, &blk, arg, txg);
if (error)
break;
lrbuf = abuf->b_data;
ztp = (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1;
blk = ztp->zit_next_blk;
if (parse_lr_func == NULL) {
VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
continue;
}
for (lrp = lrbuf; lrp < lrbuf + ztp->zit_nused; lrp += reclen) {
lr_t *lr = (lr_t *)lrp;
reclen = lr->lrc_reclen;
ASSERT3U(reclen, >=, sizeof (lr_t));
parse_lr_func(zilog, lr, arg, txg);
}
VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
}
zil_dva_tree_fini(&zilog->zl_dva_tree);
return (max_seq);
}
/* ARGSUSED */
static void
zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
{
spa_t *spa = zilog->zl_spa;
int err;
/*
* Claim log block if not already committed and not already claimed.
*/
if (bp->blk_birth >= first_txg &&
zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp)) == 0) {
err = zio_wait(zio_claim(NULL, spa, first_txg, bp, NULL, NULL,
ZIO_FLAG_MUSTSUCCEED));
ASSERT(err == 0);
}
}
static void
zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
{
if (lrc->lrc_txtype == TX_WRITE) {
lr_write_t *lr = (lr_write_t *)lrc;
zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg);
}
}
/* ARGSUSED */
static void
zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
{
zio_free_blk(zilog->zl_spa, bp, dmu_tx_get_txg(tx));
}
static void
zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
{
/*
* If we previously claimed it, we need to free it.
*/
if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE) {
lr_write_t *lr = (lr_write_t *)lrc;
blkptr_t *bp = &lr->lr_blkptr;
if (bp->blk_birth >= claim_txg &&
!zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp))) {
(void) arc_free(NULL, zilog->zl_spa,
dmu_tx_get_txg(tx), bp, NULL, NULL, ARC_WAIT);
}
}
}
/*
* Create an on-disk intent log.
*/
static void
zil_create(zilog_t *zilog)
{
const zil_header_t *zh = zilog->zl_header;
lwb_t *lwb;
uint64_t txg = 0;
dmu_tx_t *tx = NULL;
blkptr_t blk;
int error = 0;
/*
* Wait for any previous destroy to complete.
*/
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
ASSERT(zh->zh_claim_txg == 0);
ASSERT(zh->zh_replay_seq == 0);
blk = zh->zh_log;
/*
* If we don't already have an initial log block or we have one
* but it's the wrong endianness then allocate one.
*/
if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
tx = dmu_tx_create(zilog->zl_os);
(void) dmu_tx_assign(tx, TXG_WAIT);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
if (!BP_IS_HOLE(&blk)) {
zio_free_blk(zilog->zl_spa, &blk, txg);
BP_ZERO(&blk);
}
error = zio_alloc_blk(zilog->zl_spa, ZIL_MIN_BLKSZ, &blk,
NULL, txg);
if (error == 0)
zil_init_log_chain(zilog, &blk);
}
/*
* Allocate a log write buffer (lwb) for the first log block.
*/
if (error == 0) {
lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
lwb->lwb_zilog = zilog;
lwb->lwb_blk = blk;
lwb->lwb_nused = 0;
lwb->lwb_sz = BP_GET_LSIZE(&lwb->lwb_blk);
lwb->lwb_buf = zio_buf_alloc(lwb->lwb_sz);
lwb->lwb_max_txg = txg;
lwb->lwb_zio = NULL;
mutex_enter(&zilog->zl_lock);
list_insert_tail(&zilog->zl_lwb_list, lwb);
mutex_exit(&zilog->zl_lock);
}
/*
* If we just allocated the first log block, commit our transaction
* and wait for zil_sync() to stuff the block poiner into zh_log.
* (zh is part of the MOS, so we cannot modify it in open context.)
*/
if (tx != NULL) {
dmu_tx_commit(tx);
txg_wait_synced(zilog->zl_dmu_pool, txg);
}
ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
}
/*
* In one tx, free all log blocks and clear the log header.
* If keep_first is set, then we're replaying a log with no content.
* We want to keep the first block, however, so that the first
* synchronous transaction doesn't require a txg_wait_synced()
* in zil_create(). We don't need to txg_wait_synced() here either
* when keep_first is set, because both zil_create() and zil_destroy()
* will wait for any in-progress destroys to complete.
*/
void
zil_destroy(zilog_t *zilog, boolean_t keep_first)
{
const zil_header_t *zh = zilog->zl_header;
lwb_t *lwb;
dmu_tx_t *tx;
uint64_t txg;
/*
* Wait for any previous destroy to complete.
*/
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
if (BP_IS_HOLE(&zh->zh_log))
return;
tx = dmu_tx_create(zilog->zl_os);
(void) dmu_tx_assign(tx, TXG_WAIT);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
mutex_enter(&zilog->zl_lock);
/*
* It is possible for the ZIL to get the previously mounted zilog
* structure of the same dataset if quickly remounted and the dbuf
* eviction has not completed. In this case we can see a non
* empty lwb list and keep_first will be set. We fix this by
* clearing the keep_first. This will be slower but it's very rare.
*/
if (!list_is_empty(&zilog->zl_lwb_list) && keep_first)
keep_first = B_FALSE;
ASSERT3U(zilog->zl_destroy_txg, <, txg);
zilog->zl_destroy_txg = txg;
zilog->zl_keep_first = keep_first;
if (!list_is_empty(&zilog->zl_lwb_list)) {
ASSERT(zh->zh_claim_txg == 0);
ASSERT(!keep_first);
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
list_remove(&zilog->zl_lwb_list, lwb);
if (lwb->lwb_buf != NULL)
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
zio_free_blk(zilog->zl_spa, &lwb->lwb_blk, txg);
kmem_cache_free(zil_lwb_cache, lwb);
}
} else {
if (!keep_first) {
(void) zil_parse(zilog, zil_free_log_block,
zil_free_log_record, tx, zh->zh_claim_txg);
}
}
mutex_exit(&zilog->zl_lock);
dmu_tx_commit(tx);
}
/*
* return true if the initial log block is not valid
*/
static boolean_t
zil_empty(zilog_t *zilog)
{
const zil_header_t *zh = zilog->zl_header;
arc_buf_t *abuf = NULL;
if (BP_IS_HOLE(&zh->zh_log))
return (B_TRUE);
if (zil_read_log_block(zilog, &zh->zh_log, &abuf) != 0)
return (B_TRUE);
VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
return (B_FALSE);
}
int
zil_claim(char *osname, void *txarg)
{
dmu_tx_t *tx = txarg;
uint64_t first_txg = dmu_tx_get_txg(tx);
zilog_t *zilog;
zil_header_t *zh;
objset_t *os;
int error;
error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
if (error) {
cmn_err(CE_WARN, "can't open objset for %s", osname);
return (0);
}
zilog = dmu_objset_zil(os);
zh = zil_header_in_syncing_context(zilog);
if (zilog->zl_spa->spa_log_state == SPA_LOG_CLEAR) {
if (!BP_IS_HOLE(&zh->zh_log))
zio_free_blk(zilog->zl_spa, &zh->zh_log, first_txg);
BP_ZERO(&zh->zh_log);
dsl_dataset_dirty(dmu_objset_ds(os), tx);
}
/*
* Record here whether the zil has any records to replay.
* If the header block pointer is null or the block points
* to the stubby then we know there are no valid log records.
* We use the header to store this state as the the zilog gets
* freed later in dmu_objset_close().
* The flags (and the rest of the header fields) are cleared in
* zil_sync() as a result of a zil_destroy(), after replaying the log.
*
* Note, the intent log can be empty but still need the
* stubby to be claimed.
*/
if (!zil_empty(zilog)) {
zh->zh_flags |= ZIL_REPLAY_NEEDED;
dsl_dataset_dirty(dmu_objset_ds(os), tx);
}
/*
* Claim all log blocks if we haven't already done so, and remember
* the highest claimed sequence number. This ensures that if we can
* read only part of the log now (e.g. due to a missing device),
* but we can read the entire log later, we will not try to replay
* or destroy beyond the last block we successfully claimed.
*/
ASSERT3U(zh->zh_claim_txg, <=, first_txg);
if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
zh->zh_claim_txg = first_txg;
zh->zh_claim_seq = zil_parse(zilog, zil_claim_log_block,
zil_claim_log_record, tx, first_txg);
dsl_dataset_dirty(dmu_objset_ds(os), tx);
}
ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
dmu_objset_close(os);
return (0);
}
/*
* Check the log by walking the log chain.
* Checksum errors are ok as they indicate the end of the chain.
* Any other error (no device or read failure) returns an error.
*/
/* ARGSUSED */
int
zil_check_log_chain(char *osname, void *txarg)
{
zilog_t *zilog;
zil_header_t *zh;
blkptr_t blk;
arc_buf_t *abuf;
objset_t *os;
char *lrbuf;
zil_trailer_t *ztp;
int error;
error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
if (error) {
cmn_err(CE_WARN, "can't open objset for %s", osname);
return (0);
}
zilog = dmu_objset_zil(os);
zh = zil_header_in_syncing_context(zilog);
blk = zh->zh_log;
if (BP_IS_HOLE(&blk)) {
dmu_objset_close(os);
return (0); /* no chain */
}
for (;;) {
error = zil_read_log_block(zilog, &blk, &abuf);
if (error)
break;
lrbuf = abuf->b_data;
ztp = (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1;
blk = ztp->zit_next_blk;
VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
}
dmu_objset_close(os);
if (error == ECKSUM)
return (0); /* normal end of chain */
return (error);
}
static int
zil_vdev_compare(const void *x1, const void *x2)
{
uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
if (v1 < v2)
return (-1);
if (v1 > v2)
return (1);
return (0);
}
void
zil_add_block(zilog_t *zilog, blkptr_t *bp)
{
avl_tree_t *t = &zilog->zl_vdev_tree;
avl_index_t where;
zil_vdev_node_t *zv, zvsearch;
int ndvas = BP_GET_NDVAS(bp);
int i;
if (zfs_nocacheflush)
return;
ASSERT(zilog->zl_writer);
/*
* Even though we're zl_writer, we still need a lock because the
* zl_get_data() callbacks may have dmu_sync() done callbacks
* that will run concurrently.
*/
mutex_enter(&zilog->zl_vdev_lock);
for (i = 0; i < ndvas; i++) {
zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
if (avl_find(t, &zvsearch, &where) == NULL) {
zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
zv->zv_vdev = zvsearch.zv_vdev;
avl_insert(t, zv, where);
}
}
mutex_exit(&zilog->zl_vdev_lock);
}
void
zil_flush_vdevs(zilog_t *zilog)
{
spa_t *spa = zilog->zl_spa;
avl_tree_t *t = &zilog->zl_vdev_tree;
void *cookie = NULL;
zil_vdev_node_t *zv;
zio_t *zio;
ASSERT(zilog->zl_writer);
/*
* We don't need zl_vdev_lock here because we're the zl_writer,
* and all zl_get_data() callbacks are done.
*/
if (avl_numnodes(t) == 0)
return;
spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
if (vd != NULL)
zio_flush(zio, vd);
kmem_free(zv, sizeof (*zv));
}
/*
* Wait for all the flushes to complete. Not all devices actually
* support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
*/
(void) zio_wait(zio);
spa_config_exit(spa, SCL_STATE, FTAG);
}
/*
* Function called when a log block write completes
*/
static void
zil_lwb_write_done(zio_t *zio)
{
lwb_t *lwb = zio->io_private;
zilog_t *zilog = lwb->lwb_zilog;
ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
ASSERT(BP_GET_CHECKSUM(zio->io_bp) == ZIO_CHECKSUM_ZILOG);
ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
ASSERT(!BP_IS_GANG(zio->io_bp));
ASSERT(!BP_IS_HOLE(zio->io_bp));
ASSERT(zio->io_bp->blk_fill == 0);
/*
* Ensure the lwb buffer pointer is cleared before releasing
* the txg. If we have had an allocation failure and
* the txg is waiting to sync then we want want zil_sync()
* to remove the lwb so that it's not picked up as the next new
* one in zil_commit_writer(). zil_sync() will only remove
* the lwb if lwb_buf is null.
*/
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
mutex_enter(&zilog->zl_lock);
lwb->lwb_buf = NULL;
if (zio->io_error)
zilog->zl_log_error = B_TRUE;
/*
* Now that we've written this log block, we have a stable pointer
* to the next block in the chain, so it's OK to let the txg in
* which we allocated the next block sync. We still have the
* zl_lock to ensure zil_sync doesn't kmem free the lwb.
*/
txg_rele_to_sync(&lwb->lwb_txgh);
mutex_exit(&zilog->zl_lock);
}
/*
* Initialize the io for a log block.
*/
static void
zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
{
zbookmark_t zb;
zb.zb_objset = lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET];
zb.zb_object = 0;
zb.zb_level = -1;
zb.zb_blkid = lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
if (zilog->zl_root_zio == NULL) {
zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
ZIO_FLAG_CANFAIL);
}
if (lwb->lwb_zio == NULL) {
lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
0, &lwb->lwb_blk, lwb->lwb_buf, lwb->lwb_sz,
zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb);
}
}
/*
* Start a log block write and advance to the next log block.
* Calls are serialized.
*/
static lwb_t *
zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
{
lwb_t *nlwb;
zil_trailer_t *ztp = (zil_trailer_t *)(lwb->lwb_buf + lwb->lwb_sz) - 1;
spa_t *spa = zilog->zl_spa;
blkptr_t *bp = &ztp->zit_next_blk;
uint64_t txg;
uint64_t zil_blksz;
int error;
ASSERT(lwb->lwb_nused <= ZIL_BLK_DATA_SZ(lwb));
/*
* Allocate the next block and save its address in this block
* before writing it in order to establish the log chain.
* Note that if the allocation of nlwb synced before we wrote
* the block that points at it (lwb), we'd leak it if we crashed.
* Therefore, we don't do txg_rele_to_sync() until zil_lwb_write_done().
*/
txg = txg_hold_open(zilog->zl_dmu_pool, &lwb->lwb_txgh);
txg_rele_to_quiesce(&lwb->lwb_txgh);
/*
* Pick a ZIL blocksize. We request a size that is the
* maximum of the previous used size, the current used size and
* the amount waiting in the queue.
*/
zil_blksz = MAX(zilog->zl_prev_used,
zilog->zl_cur_used + sizeof (*ztp));
zil_blksz = MAX(zil_blksz, zilog->zl_itx_list_sz + sizeof (*ztp));
zil_blksz = P2ROUNDUP_TYPED(zil_blksz, ZIL_MIN_BLKSZ, uint64_t);
if (zil_blksz > ZIL_MAX_BLKSZ)
zil_blksz = ZIL_MAX_BLKSZ;
BP_ZERO(bp);
/* pass the old blkptr in order to spread log blocks across devs */
error = zio_alloc_blk(spa, zil_blksz, bp, &lwb->lwb_blk, txg);
if (error) {
dmu_tx_t *tx = dmu_tx_create_assigned(zilog->zl_dmu_pool, txg);
/*
* We dirty the dataset to ensure that zil_sync() will
* be called to remove this lwb from our zl_lwb_list.
* Failing to do so, may leave an lwb with a NULL lwb_buf
* hanging around on the zl_lwb_list.
*/
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
dmu_tx_commit(tx);
/*
* Since we've just experienced an allocation failure so we
* terminate the current lwb and send it on its way.
*/
ztp->zit_pad = 0;
ztp->zit_nused = lwb->lwb_nused;
ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum;
zio_nowait(lwb->lwb_zio);
/*
* By returning NULL the caller will call tx_wait_synced()
*/
return (NULL);
}
ASSERT3U(bp->blk_birth, ==, txg);
ztp->zit_pad = 0;
ztp->zit_nused = lwb->lwb_nused;
ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum;
bp->blk_cksum = lwb->lwb_blk.blk_cksum;
bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
/*
* Allocate a new log write buffer (lwb).
*/
nlwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
nlwb->lwb_zilog = zilog;
nlwb->lwb_blk = *bp;
nlwb->lwb_nused = 0;
nlwb->lwb_sz = BP_GET_LSIZE(&nlwb->lwb_blk);
nlwb->lwb_buf = zio_buf_alloc(nlwb->lwb_sz);
nlwb->lwb_max_txg = txg;
nlwb->lwb_zio = NULL;
/*
* Put new lwb at the end of the log chain
*/
mutex_enter(&zilog->zl_lock);
list_insert_tail(&zilog->zl_lwb_list, nlwb);
mutex_exit(&zilog->zl_lock);
/* Record the block for later vdev flushing */
zil_add_block(zilog, &lwb->lwb_blk);
/*
* kick off the write for the old log block
*/
dprintf_bp(&lwb->lwb_blk, "lwb %p txg %llu: ", lwb, txg);
ASSERT(lwb->lwb_zio);
zio_nowait(lwb->lwb_zio);
return (nlwb);
}
static lwb_t *
zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
{
lr_t *lrc = &itx->itx_lr; /* common log record */
lr_write_t *lr = (lr_write_t *)lrc;
uint64_t txg = lrc->lrc_txg;
uint64_t reclen = lrc->lrc_reclen;
uint64_t dlen;
if (lwb == NULL)
return (NULL);
ASSERT(lwb->lwb_buf != NULL);
if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
dlen = P2ROUNDUP_TYPED(
lr->lr_length, sizeof (uint64_t), uint64_t);
else
dlen = 0;
zilog->zl_cur_used += (reclen + dlen);
zil_lwb_write_init(zilog, lwb);
/*
* If this record won't fit in the current log block, start a new one.
*/
if (lwb->lwb_nused + reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) {
lwb = zil_lwb_write_start(zilog, lwb);
if (lwb == NULL)
return (NULL);
zil_lwb_write_init(zilog, lwb);
ASSERT(lwb->lwb_nused == 0);
if (reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) {
txg_wait_synced(zilog->zl_dmu_pool, txg);
return (lwb);
}
}
/*
* Update the lrc_seq, to be log record sequence number. See zil.h
* Then copy the record to the log buffer.
*/
lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
bcopy(lrc, lwb->lwb_buf + lwb->lwb_nused, reclen);
/*
* If it's a write, fetch the data or get its blkptr as appropriate.
*/
if (lrc->lrc_txtype == TX_WRITE) {
if (txg > spa_freeze_txg(zilog->zl_spa))
txg_wait_synced(zilog->zl_dmu_pool, txg);
if (itx->itx_wr_state != WR_COPIED) {
char *dbuf;
int error;
/* alignment is guaranteed */
lr = (lr_write_t *)(lwb->lwb_buf + lwb->lwb_nused);
if (dlen) {
ASSERT(itx->itx_wr_state == WR_NEED_COPY);
dbuf = lwb->lwb_buf + lwb->lwb_nused + reclen;
lr->lr_common.lrc_reclen += dlen;
} else {
ASSERT(itx->itx_wr_state == WR_INDIRECT);
dbuf = NULL;
}
error = zilog->zl_get_data(
itx->itx_private, lr, dbuf, lwb->lwb_zio);
if (error == EIO) {
txg_wait_synced(zilog->zl_dmu_pool, txg);
return (lwb);
}
if (error) {
ASSERT(error == ENOENT || error == EEXIST ||
error == EALREADY);
return (lwb);
}
}
}
lwb->lwb_nused += reclen + dlen;
lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
ASSERT3U(lwb->lwb_nused, <=, ZIL_BLK_DATA_SZ(lwb));
ASSERT3U(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)), ==, 0);
return (lwb);
}
itx_t *
zil_itx_create(uint64_t txtype, size_t lrsize)
{
itx_t *itx;
lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
itx->itx_lr.lrc_txtype = txtype;
itx->itx_lr.lrc_reclen = lrsize;
itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
itx->itx_lr.lrc_seq = 0; /* defensive */
return (itx);
}
uint64_t
zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
{
uint64_t seq;
ASSERT(itx->itx_lr.lrc_seq == 0);
mutex_enter(&zilog->zl_lock);
list_insert_tail(&zilog->zl_itx_list, itx);
zilog->zl_itx_list_sz += itx->itx_sod;
itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
itx->itx_lr.lrc_seq = seq = ++zilog->zl_itx_seq;
mutex_exit(&zilog->zl_lock);
return (seq);
}
/*
* Free up all in-memory intent log transactions that have now been synced.
*/
static void
zil_itx_clean(zilog_t *zilog)
{
uint64_t synced_txg = spa_last_synced_txg(zilog->zl_spa);
uint64_t freeze_txg = spa_freeze_txg(zilog->zl_spa);
list_t clean_list;
itx_t *itx;
list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
mutex_enter(&zilog->zl_lock);
/* wait for a log writer to finish walking list */
while (zilog->zl_writer) {
cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
}
/*
* Move the sync'd log transactions to a separate list so we can call
* kmem_free without holding the zl_lock.
*
* There is no need to set zl_writer as we don't drop zl_lock here
*/
while ((itx = list_head(&zilog->zl_itx_list)) != NULL &&
itx->itx_lr.lrc_txg <= MIN(synced_txg, freeze_txg)) {
list_remove(&zilog->zl_itx_list, itx);
zilog->zl_itx_list_sz -= itx->itx_sod;
list_insert_tail(&clean_list, itx);
}
cv_broadcast(&zilog->zl_cv_writer);
mutex_exit(&zilog->zl_lock);
/* destroy sync'd log transactions */
while ((itx = list_head(&clean_list)) != NULL) {
list_remove(&clean_list, itx);
kmem_free(itx, offsetof(itx_t, itx_lr)
+ itx->itx_lr.lrc_reclen);
}
list_destroy(&clean_list);
}
/*
* If there are any in-memory intent log transactions which have now been
* synced then start up a taskq to free them.
*/
void
zil_clean(zilog_t *zilog)
{
itx_t *itx;
mutex_enter(&zilog->zl_lock);
itx = list_head(&zilog->zl_itx_list);
if ((itx != NULL) &&
(itx->itx_lr.lrc_txg <= spa_last_synced_txg(zilog->zl_spa))) {
(void) taskq_dispatch(zilog->zl_clean_taskq,
(task_func_t *)zil_itx_clean, zilog, TQ_SLEEP);
}
mutex_exit(&zilog->zl_lock);
}
static void
zil_commit_writer(zilog_t *zilog, uint64_t seq, uint64_t foid)
{
uint64_t txg;
uint64_t commit_seq = 0;
itx_t *itx, *itx_next = (itx_t *)-1;
lwb_t *lwb;
spa_t *spa;
zilog->zl_writer = B_TRUE;
ASSERT(zilog->zl_root_zio == NULL);
spa = zilog->zl_spa;
if (zilog->zl_suspend) {
lwb = NULL;
} else {
lwb = list_tail(&zilog->zl_lwb_list);
if (lwb == NULL) {
/*
* Return if there's nothing to flush before we
* dirty the fs by calling zil_create()
*/
if (list_is_empty(&zilog->zl_itx_list)) {
zilog->zl_writer = B_FALSE;
return;
}
mutex_exit(&zilog->zl_lock);
zil_create(zilog);
mutex_enter(&zilog->zl_lock);
lwb = list_tail(&zilog->zl_lwb_list);
}
}
/* Loop through in-memory log transactions filling log blocks. */
DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
for (;;) {
/*
* Find the next itx to push:
* Push all transactions related to specified foid and all
* other transactions except TX_WRITE, TX_TRUNCATE,
* TX_SETATTR and TX_ACL for all other files.
*/
if (itx_next != (itx_t *)-1)
itx = itx_next;
else
itx = list_head(&zilog->zl_itx_list);
for (; itx != NULL; itx = list_next(&zilog->zl_itx_list, itx)) {
if (foid == 0) /* push all foids? */
break;
if (itx->itx_sync) /* push all O_[D]SYNC */
break;
switch (itx->itx_lr.lrc_txtype) {
case TX_SETATTR:
case TX_WRITE:
case TX_TRUNCATE:
case TX_ACL:
/* lr_foid is same offset for these records */
if (((lr_write_t *)&itx->itx_lr)->lr_foid
!= foid) {
continue; /* skip this record */
}
}
break;
}
if (itx == NULL)
break;
if ((itx->itx_lr.lrc_seq > seq) &&
((lwb == NULL) || (lwb->lwb_nused == 0) ||
(lwb->lwb_nused + itx->itx_sod > ZIL_BLK_DATA_SZ(lwb)))) {
break;
}
/*
* Save the next pointer. Even though we soon drop
* zl_lock all threads that may change the list
* (another writer or zil_itx_clean) can't do so until
* they have zl_writer.
*/
itx_next = list_next(&zilog->zl_itx_list, itx);
list_remove(&zilog->zl_itx_list, itx);
zilog->zl_itx_list_sz -= itx->itx_sod;
mutex_exit(&zilog->zl_lock);
txg = itx->itx_lr.lrc_txg;
ASSERT(txg);
if (txg > spa_last_synced_txg(spa) ||
txg > spa_freeze_txg(spa))
lwb = zil_lwb_commit(zilog, itx, lwb);
kmem_free(itx, offsetof(itx_t, itx_lr)
+ itx->itx_lr.lrc_reclen);
mutex_enter(&zilog->zl_lock);
}
DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
/* determine commit sequence number */
itx = list_head(&zilog->zl_itx_list);
if (itx)
commit_seq = itx->itx_lr.lrc_seq;
else
commit_seq = zilog->zl_itx_seq;
mutex_exit(&zilog->zl_lock);
/* write the last block out */
if (lwb != NULL && lwb->lwb_zio != NULL)
lwb = zil_lwb_write_start(zilog, lwb);
zilog->zl_prev_used = zilog->zl_cur_used;
zilog->zl_cur_used = 0;
/*
* Wait if necessary for the log blocks to be on stable storage.
*/
if (zilog->zl_root_zio) {
DTRACE_PROBE1(zil__cw3, zilog_t *, zilog);
(void) zio_wait(zilog->zl_root_zio);
zilog->zl_root_zio = NULL;
DTRACE_PROBE1(zil__cw4, zilog_t *, zilog);
zil_flush_vdevs(zilog);
}
if (zilog->zl_log_error || lwb == NULL) {
zilog->zl_log_error = 0;
txg_wait_synced(zilog->zl_dmu_pool, 0);
}
mutex_enter(&zilog->zl_lock);
zilog->zl_writer = B_FALSE;
ASSERT3U(commit_seq, >=, zilog->zl_commit_seq);
zilog->zl_commit_seq = commit_seq;
}
/*
* Push zfs transactions to stable storage up to the supplied sequence number.
* If foid is 0 push out all transactions, otherwise push only those
* for that file or might have been used to create that file.
*/
void
zil_commit(zilog_t *zilog, uint64_t seq, uint64_t foid)
{
if (zilog == NULL || seq == 0)
return;
mutex_enter(&zilog->zl_lock);
seq = MIN(seq, zilog->zl_itx_seq); /* cap seq at largest itx seq */
while (zilog->zl_writer) {
cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
if (seq < zilog->zl_commit_seq) {
mutex_exit(&zilog->zl_lock);
return;
}
}
zil_commit_writer(zilog, seq, foid); /* drops zl_lock */
/* wake up others waiting on the commit */
cv_broadcast(&zilog->zl_cv_writer);
mutex_exit(&zilog->zl_lock);
}
/*
* Called in syncing context to free committed log blocks and update log header.
*/
void
zil_sync(zilog_t *zilog, dmu_tx_t *tx)
{
zil_header_t *zh = zil_header_in_syncing_context(zilog);
uint64_t txg = dmu_tx_get_txg(tx);
spa_t *spa = zilog->zl_spa;
lwb_t *lwb;
/*
* We don't zero out zl_destroy_txg, so make sure we don't try
* to destroy it twice.
*/
if (spa_sync_pass(spa) != 1)
return;
mutex_enter(&zilog->zl_lock);
ASSERT(zilog->zl_stop_sync == 0);
zh->zh_replay_seq = zilog->zl_replayed_seq[txg & TXG_MASK];
if (zilog->zl_destroy_txg == txg) {
blkptr_t blk = zh->zh_log;
ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
bzero(zh, sizeof (zil_header_t));
bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
if (zilog->zl_keep_first) {
/*
* If this block was part of log chain that couldn't
* be claimed because a device was missing during
* zil_claim(), but that device later returns,
* then this block could erroneously appear valid.
* To guard against this, assign a new GUID to the new
* log chain so it doesn't matter what blk points to.
*/
zil_init_log_chain(zilog, &blk);
zh->zh_log = blk;
}
}
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
zh->zh_log = lwb->lwb_blk;
if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
break;
list_remove(&zilog->zl_lwb_list, lwb);
zio_free_blk(spa, &lwb->lwb_blk, txg);
kmem_cache_free(zil_lwb_cache, lwb);
/*
* If we don't have anything left in the lwb list then
* we've had an allocation failure and we need to zero
* out the zil_header blkptr so that we don't end
* up freeing the same block twice.
*/
if (list_head(&zilog->zl_lwb_list) == NULL)
BP_ZERO(&zh->zh_log);
}
mutex_exit(&zilog->zl_lock);
}
void
zil_init(void)
{
zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
}
void
zil_fini(void)
{
kmem_cache_destroy(zil_lwb_cache);
}
zilog_t *
zil_alloc(objset_t *os, zil_header_t *zh_phys)
{
zilog_t *zilog;
zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
zilog->zl_header = zh_phys;
zilog->zl_os = os;
zilog->zl_spa = dmu_objset_spa(os);
zilog->zl_dmu_pool = dmu_objset_pool(os);
zilog->zl_destroy_txg = TXG_INITIAL - 1;
mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
list_create(&zilog->zl_itx_list, sizeof (itx_t),
offsetof(itx_t, itx_node));
list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
offsetof(lwb_t, lwb_node));
mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
return (zilog);
}
void
zil_free(zilog_t *zilog)
{
lwb_t *lwb;
zilog->zl_stop_sync = 1;
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
list_remove(&zilog->zl_lwb_list, lwb);
if (lwb->lwb_buf != NULL)
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
kmem_cache_free(zil_lwb_cache, lwb);
}
list_destroy(&zilog->zl_lwb_list);
avl_destroy(&zilog->zl_vdev_tree);
mutex_destroy(&zilog->zl_vdev_lock);
ASSERT(list_head(&zilog->zl_itx_list) == NULL);
list_destroy(&zilog->zl_itx_list);
mutex_destroy(&zilog->zl_lock);
cv_destroy(&zilog->zl_cv_writer);
cv_destroy(&zilog->zl_cv_suspend);
kmem_free(zilog, sizeof (zilog_t));
}
/*
* Open an intent log.
*/
zilog_t *
zil_open(objset_t *os, zil_get_data_t *get_data)
{
zilog_t *zilog = dmu_objset_zil(os);
zilog->zl_get_data = get_data;
zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
2, 2, TASKQ_PREPOPULATE);
return (zilog);
}
/*
* Close an intent log.
*/
void
zil_close(zilog_t *zilog)
{
/*
* If the log isn't already committed, mark the objset dirty
* (so zil_sync() will be called) and wait for that txg to sync.
*/
if (!zil_is_committed(zilog)) {
uint64_t txg;
dmu_tx_t *tx = dmu_tx_create(zilog->zl_os);
(void) dmu_tx_assign(tx, TXG_WAIT);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
dmu_tx_commit(tx);
txg_wait_synced(zilog->zl_dmu_pool, txg);
}
taskq_destroy(zilog->zl_clean_taskq);
zilog->zl_clean_taskq = NULL;
zilog->zl_get_data = NULL;
zil_itx_clean(zilog);
ASSERT(list_head(&zilog->zl_itx_list) == NULL);
}
/*
* Suspend an intent log. While in suspended mode, we still honor
* synchronous semantics, but we rely on txg_wait_synced() to do it.
* We suspend the log briefly when taking a snapshot so that the snapshot
* contains all the data it's supposed to, and has an empty intent log.
*/
int
zil_suspend(zilog_t *zilog)
{
const zil_header_t *zh = zilog->zl_header;
mutex_enter(&zilog->zl_lock);
if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
mutex_exit(&zilog->zl_lock);
return (EBUSY);
}
if (zilog->zl_suspend++ != 0) {
/*
* Someone else already began a suspend.
* Just wait for them to finish.
*/
while (zilog->zl_suspending)
cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
mutex_exit(&zilog->zl_lock);
return (0);
}
zilog->zl_suspending = B_TRUE;
mutex_exit(&zilog->zl_lock);
zil_commit(zilog, UINT64_MAX, 0);
/*
* Wait for any in-flight log writes to complete.
*/
mutex_enter(&zilog->zl_lock);
while (zilog->zl_writer)
cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
mutex_exit(&zilog->zl_lock);
zil_destroy(zilog, B_FALSE);
mutex_enter(&zilog->zl_lock);
zilog->zl_suspending = B_FALSE;
cv_broadcast(&zilog->zl_cv_suspend);
mutex_exit(&zilog->zl_lock);
return (0);
}
void
zil_resume(zilog_t *zilog)
{
mutex_enter(&zilog->zl_lock);
ASSERT(zilog->zl_suspend != 0);
zilog->zl_suspend--;
mutex_exit(&zilog->zl_lock);
}
typedef struct zil_replay_arg {
objset_t *zr_os;
zil_replay_func_t **zr_replay;
void *zr_arg;
boolean_t zr_byteswap;
char *zr_lrbuf;
} zil_replay_arg_t;
static void
zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
{
zil_replay_arg_t *zr = zra;
const zil_header_t *zh = zilog->zl_header;
uint64_t reclen = lr->lrc_reclen;
uint64_t txtype = lr->lrc_txtype;
char *name;
int pass, error;
if (!zilog->zl_replay) /* giving up */
return;
if (lr->lrc_txg < claim_txg) /* already committed */
return;
if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
return;
/* Strip case-insensitive bit, still present in log record */
txtype &= ~TX_CI;
if (txtype == 0 || txtype >= TX_MAX_TYPE) {
error = EINVAL;
goto bad;
}
/*
* Make a copy of the data so we can revise and extend it.
*/
bcopy(lr, zr->zr_lrbuf, reclen);
/*
* The log block containing this lr may have been byteswapped
* so that we can easily examine common fields like lrc_txtype.
* However, the log is a mix of different data types, and only the
* replay vectors know how to byteswap their records. Therefore, if
* the lr was byteswapped, undo it before invoking the replay vector.
*/
if (zr->zr_byteswap)
byteswap_uint64_array(zr->zr_lrbuf, reclen);
/*
* If this is a TX_WRITE with a blkptr, suck in the data.
*/
if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
lr_write_t *lrw = (lr_write_t *)lr;
blkptr_t *wbp = &lrw->lr_blkptr;
uint64_t wlen = lrw->lr_length;
char *wbuf = zr->zr_lrbuf + reclen;
if (BP_IS_HOLE(wbp)) { /* compressed to a hole */
bzero(wbuf, wlen);
} else {
/*
* A subsequent write may have overwritten this block,
* in which case wbp may have been been freed and
* reallocated, and our read of wbp may fail with a
* checksum error. We can safely ignore this because
* the later write will provide the correct data.
*/
zbookmark_t zb;
zb.zb_objset = dmu_objset_id(zilog->zl_os);
zb.zb_object = lrw->lr_foid;
zb.zb_level = -1;
zb.zb_blkid = lrw->lr_offset / BP_GET_LSIZE(wbp);
(void) zio_wait(zio_read(NULL, zilog->zl_spa,
wbp, wbuf, BP_GET_LSIZE(wbp), NULL, NULL,
ZIO_PRIORITY_SYNC_READ,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb));
(void) memmove(wbuf, wbuf + lrw->lr_blkoff, wlen);
}
}
/*
* We must now do two things atomically: replay this log record,
* and update the log header sequence number to reflect the fact that
* we did so. At the end of each replay function the sequence number
* is updated if we are in replay mode.
*/
for (pass = 1; pass <= 2; pass++) {
zilog->zl_replaying_seq = lr->lrc_seq;
/* Only byteswap (if needed) on the 1st pass. */
error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lrbuf,
zr->zr_byteswap && pass == 1);
if (!error)
return;
/*
* The DMU's dnode layer doesn't see removes until the txg
* commits, so a subsequent claim can spuriously fail with
* EEXIST. So if we receive any error we try syncing out
* any removes then retry the transaction.
*/
if (pass == 1)
txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
}
bad:
ASSERT(error);
name = kmem_alloc(MAXNAMELEN, KM_SLEEP);
dmu_objset_name(zr->zr_os, name);
cmn_err(CE_WARN, "ZFS replay transaction error %d, "
"dataset %s, seq 0x%llx, txtype %llu %s\n",
error, name, (u_longlong_t)lr->lrc_seq, (u_longlong_t)txtype,
(lr->lrc_txtype & TX_CI) ? "CI" : "");
zilog->zl_replay = B_FALSE;
kmem_free(name, MAXNAMELEN);
}
/* ARGSUSED */
static void
zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
{
zilog->zl_replay_blks++;
}
/*
* If this dataset has a non-empty intent log, replay it and destroy it.
*/
void
zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
{
zilog_t *zilog = dmu_objset_zil(os);
const zil_header_t *zh = zilog->zl_header;
zil_replay_arg_t zr;
if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
zil_destroy(zilog, B_TRUE);
return;
}
zr.zr_os = os;
zr.zr_replay = replay_func;
zr.zr_arg = arg;
zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
/* XXX: Changed to use vmem_alloc instead of kmem_alloc for
* large allocation size (I think this is safe here).
*/
zr.zr_lrbuf = vmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
/*
* Wait for in-progress removes to sync before starting replay.
*/
txg_wait_synced(zilog->zl_dmu_pool, 0);
zilog->zl_replay = B_TRUE;
zilog->zl_replay_time = lbolt;
ASSERT(zilog->zl_replay_blks == 0);
(void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
zh->zh_claim_txg);
vmem_free(zr.zr_lrbuf, 2 * SPA_MAXBLOCKSIZE);
zil_destroy(zilog, B_FALSE);
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
zilog->zl_replay = B_FALSE;
}
/*
* Report whether all transactions are committed
*/
int
zil_is_committed(zilog_t *zilog)
{
lwb_t *lwb;
int ret;
mutex_enter(&zilog->zl_lock);
while (zilog->zl_writer)
cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
/* recent unpushed intent log transactions? */
if (!list_is_empty(&zilog->zl_itx_list)) {
ret = B_FALSE;
goto out;
}
/* intent log never used? */
lwb = list_head(&zilog->zl_lwb_list);
if (lwb == NULL) {
ret = B_TRUE;
goto out;
}
/*
* more than 1 log buffer means zil_sync() hasn't yet freed
* entries after a txg has committed
*/
if (list_next(&zilog->zl_lwb_list, lwb)) {
ret = B_FALSE;
goto out;
}
ASSERT(zil_empty(zilog));
ret = B_TRUE;
out:
cv_broadcast(&zilog->zl_cv_writer);
mutex_exit(&zilog->zl_lock);
return (ret);
}
/* ARGSUSED */
int
zil_vdev_offline(char *osname, void *arg)
{
objset_t *os;
zilog_t *zilog;
int error;
error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
if (error)
return (error);
zilog = dmu_objset_zil(os);
if (zil_suspend(zilog) != 0)
error = EEXIST;
else
zil_resume(zilog);
dmu_objset_close(os);
return (error);
}