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-rw-r--r--uts/common/fs/zfs/zil.c1992
1 files changed, 1992 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/zil.c b/uts/common/fs/zfs/zil.c
new file mode 100644
index 000000000000..c66313ff6f85
--- /dev/null
+++ b/uts/common/fs/zfs/zil.c
@@ -0,0 +1,1992 @@
+/*
+ * 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.
+ */
+
+/* Portions Copyright 2010 Robert Milkowski */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.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_impl.h>
+#include <sys/dmu_tx.h>
+#include <sys/dsl_pool.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_replay_disable = 0; /* disable intent logging replay */
+
+/*
+ * 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 void zil_async_to_sync(zilog_t *zilog, uint64_t foid);
+
+#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
+ sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
+
+
+/*
+ * ziltest is by and large an ugly hack, but very useful in
+ * checking replay without tedious work.
+ * When running ziltest we want to keep all itx's and so maintain
+ * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG
+ * We subtract TXG_CONCURRENT_STATES to allow for common code.
+ */
+#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES)
+
+static int
+zil_bp_compare(const void *x1, const void *x2)
+{
+ const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva;
+ const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva;
+
+ 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_bp_tree_init(zilog_t *zilog)
+{
+ avl_create(&zilog->zl_bp_tree, zil_bp_compare,
+ sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node));
+}
+
+static void
+zil_bp_tree_fini(zilog_t *zilog)
+{
+ avl_tree_t *t = &zilog->zl_bp_tree;
+ zil_bp_node_t *zn;
+ void *cookie = NULL;
+
+ while ((zn = avl_destroy_nodes(t, &cookie)) != NULL)
+ kmem_free(zn, sizeof (zil_bp_node_t));
+
+ avl_destroy(t);
+}
+
+int
+zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp)
+{
+ avl_tree_t *t = &zilog->zl_bp_tree;
+ const dva_t *dva = BP_IDENTITY(bp);
+ zil_bp_node_t *zn;
+ avl_index_t where;
+
+ if (avl_find(t, dva, &where) != NULL)
+ return (EEXIST);
+
+ zn = kmem_alloc(sizeof (zil_bp_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 and make sure it's valid.
+ */
+static int
+zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst,
+ char **end)
+{
+ enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
+ uint32_t aflags = ARC_WAIT;
+ arc_buf_t *abuf = NULL;
+ zbookmark_t zb;
+ int error;
+
+ if (zilog->zl_header->zh_claim_txg == 0)
+ zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
+
+ if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
+ zio_flags |= ZIO_FLAG_SPECULATIVE;
+
+ SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET],
+ ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
+
+ error = dsl_read_nolock(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
+ ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
+
+ if (error == 0) {
+ 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 (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
+ zil_chain_t *zilc = abuf->b_data;
+ char *lr = (char *)(zilc + 1);
+ uint64_t len = zilc->zc_nused - sizeof (zil_chain_t);
+
+ if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
+ sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) {
+ error = ECKSUM;
+ } else {
+ bcopy(lr, dst, len);
+ *end = (char *)dst + len;
+ *nbp = zilc->zc_next_blk;
+ }
+ } else {
+ char *lr = abuf->b_data;
+ uint64_t size = BP_GET_LSIZE(bp);
+ zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1;
+
+ if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
+ sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) ||
+ (zilc->zc_nused > (size - sizeof (*zilc)))) {
+ error = ECKSUM;
+ } else {
+ bcopy(lr, dst, zilc->zc_nused);
+ *end = (char *)dst + zilc->zc_nused;
+ *nbp = zilc->zc_next_blk;
+ }
+ }
+
+ VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
+ }
+
+ return (error);
+}
+
+/*
+ * Read a TX_WRITE log data block.
+ */
+static int
+zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf)
+{
+ enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
+ const blkptr_t *bp = &lr->lr_blkptr;
+ uint32_t aflags = ARC_WAIT;
+ arc_buf_t *abuf = NULL;
+ zbookmark_t zb;
+ int error;
+
+ if (BP_IS_HOLE(bp)) {
+ if (wbuf != NULL)
+ bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length));
+ return (0);
+ }
+
+ if (zilog->zl_header->zh_claim_txg == 0)
+ zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
+
+ SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid,
+ ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
+
+ error = arc_read_nolock(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
+ ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
+
+ if (error == 0) {
+ if (wbuf != NULL)
+ bcopy(abuf->b_data, wbuf, arc_buf_size(abuf));
+ (void) arc_buf_remove_ref(abuf, &abuf);
+ }
+
+ return (error);
+}
+
+/*
+ * Parse the intent log, and call parse_func for each valid record within.
+ */
+int
+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;
+ boolean_t claimed = !!zh->zh_claim_txg;
+ uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX;
+ uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX;
+ uint64_t max_blk_seq = 0;
+ uint64_t max_lr_seq = 0;
+ uint64_t blk_count = 0;
+ uint64_t lr_count = 0;
+ blkptr_t blk, next_blk;
+ char *lrbuf, *lrp;
+ int error = 0;
+
+ /*
+ * Old logs didn't record the maximum zh_claim_lr_seq.
+ */
+ if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
+ claim_lr_seq = UINT64_MAX;
+
+ /*
+ * 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.
+ */
+ lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE);
+ zil_bp_tree_init(zilog);
+
+ for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) {
+ uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
+ int reclen;
+ char *end;
+
+ if (blk_seq > claim_blk_seq)
+ break;
+ if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0)
+ break;
+ ASSERT3U(max_blk_seq, <, blk_seq);
+ max_blk_seq = blk_seq;
+ blk_count++;
+
+ if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq)
+ break;
+
+ error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end);
+ if (error)
+ break;
+
+ for (lrp = lrbuf; lrp < end; lrp += reclen) {
+ lr_t *lr = (lr_t *)lrp;
+ reclen = lr->lrc_reclen;
+ ASSERT3U(reclen, >=, sizeof (lr_t));
+ if (lr->lrc_seq > claim_lr_seq)
+ goto done;
+ if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0)
+ goto done;
+ ASSERT3U(max_lr_seq, <, lr->lrc_seq);
+ max_lr_seq = lr->lrc_seq;
+ lr_count++;
+ }
+ }
+done:
+ zilog->zl_parse_error = error;
+ zilog->zl_parse_blk_seq = max_blk_seq;
+ zilog->zl_parse_lr_seq = max_lr_seq;
+ zilog->zl_parse_blk_count = blk_count;
+ zilog->zl_parse_lr_count = lr_count;
+
+ ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) ||
+ (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq));
+
+ zil_bp_tree_fini(zilog);
+ zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE);
+
+ return (error);
+}
+
+static int
+zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
+{
+ /*
+ * Claim log block if not already committed and not already claimed.
+ * If tx == NULL, just verify that the block is claimable.
+ */
+ if (bp->blk_birth < first_txg || zil_bp_tree_add(zilog, bp) != 0)
+ return (0);
+
+ return (zio_wait(zio_claim(NULL, zilog->zl_spa,
+ tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL,
+ ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB)));
+}
+
+static int
+zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
+{
+ lr_write_t *lr = (lr_write_t *)lrc;
+ int error;
+
+ if (lrc->lrc_txtype != TX_WRITE)
+ return (0);
+
+ /*
+ * If the block is not readable, don't claim it. This can happen
+ * in normal operation when a log block is written to disk before
+ * some of the dmu_sync() blocks it points to. In this case, the
+ * transaction cannot have been committed to anyone (we would have
+ * waited for all writes to be stable first), so it is semantically
+ * correct to declare this the end of the log.
+ */
+ if (lr->lr_blkptr.blk_birth >= first_txg &&
+ (error = zil_read_log_data(zilog, lr, NULL)) != 0)
+ return (error);
+ return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
+}
+
+/* ARGSUSED */
+static int
+zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
+{
+ zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
+
+ return (0);
+}
+
+static int
+zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
+{
+ lr_write_t *lr = (lr_write_t *)lrc;
+ blkptr_t *bp = &lr->lr_blkptr;
+
+ /*
+ * If we previously claimed it, we need to free it.
+ */
+ if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE &&
+ bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0)
+ zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
+
+ return (0);
+}
+
+static lwb_t *
+zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg)
+{
+ lwb_t *lwb;
+
+ lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
+ lwb->lwb_zilog = zilog;
+ lwb->lwb_blk = *bp;
+ lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
+ lwb->lwb_max_txg = txg;
+ lwb->lwb_zio = NULL;
+ lwb->lwb_tx = NULL;
+ if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
+ lwb->lwb_nused = sizeof (zil_chain_t);
+ lwb->lwb_sz = BP_GET_LSIZE(bp);
+ } else {
+ lwb->lwb_nused = 0;
+ lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t);
+ }
+
+ mutex_enter(&zilog->zl_lock);
+ list_insert_tail(&zilog->zl_lwb_list, lwb);
+ mutex_exit(&zilog->zl_lock);
+
+ return (lwb);
+}
+
+/*
+ * Create an on-disk intent log.
+ */
+static lwb_t *
+zil_create(zilog_t *zilog)
+{
+ const zil_header_t *zh = zilog->zl_header;
+ lwb_t *lwb = NULL;
+ 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;
+
+ /*
+ * Allocate an initial log block if:
+ * - there isn't one already
+ * - the existing block is the wrong endianess
+ */
+ if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
+ tx = dmu_tx_create(zilog->zl_os);
+ VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
+ dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
+ txg = dmu_tx_get_txg(tx);
+
+ if (!BP_IS_HOLE(&blk)) {
+ zio_free_zil(zilog->zl_spa, txg, &blk);
+ BP_ZERO(&blk);
+ }
+
+ error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL,
+ ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
+
+ if (error == 0)
+ zil_init_log_chain(zilog, &blk);
+ }
+
+ /*
+ * Allocate a log write buffer (lwb) for the first log block.
+ */
+ if (error == 0)
+ lwb = zil_alloc_lwb(zilog, &blk, txg);
+
+ /*
+ * 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);
+
+ return (lwb);
+}
+
+/*
+ * 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);
+
+ zilog->zl_old_header = *zh; /* debugging aid */
+
+ if (BP_IS_HOLE(&zh->zh_log))
+ return;
+
+ tx = dmu_tx_create(zilog->zl_os);
+ VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
+ dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
+ txg = dmu_tx_get_txg(tx);
+
+ mutex_enter(&zilog->zl_lock);
+
+ 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_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
+ 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);
+}
+
+int
+zil_claim(const 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_hold(osname, FTAG, &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 (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
+ if (!BP_IS_HOLE(&zh->zh_log))
+ zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
+ BP_ZERO(&zh->zh_log);
+ dsl_dataset_dirty(dmu_objset_ds(os), tx);
+ dmu_objset_rele(os, FTAG);
+ return (0);
+ }
+
+ /*
+ * 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)) {
+ (void) zil_parse(zilog, zil_claim_log_block,
+ zil_claim_log_record, tx, first_txg);
+ zh->zh_claim_txg = first_txg;
+ zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
+ zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
+ if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
+ zh->zh_flags |= ZIL_REPLAY_NEEDED;
+ zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
+ dsl_dataset_dirty(dmu_objset_ds(os), tx);
+ }
+
+ ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
+ dmu_objset_rele(os, FTAG);
+ 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.
+ */
+int
+zil_check_log_chain(const char *osname, void *tx)
+{
+ zilog_t *zilog;
+ objset_t *os;
+ blkptr_t *bp;
+ int error;
+
+ ASSERT(tx == NULL);
+
+ error = dmu_objset_hold(osname, FTAG, &os);
+ if (error) {
+ cmn_err(CE_WARN, "can't open objset for %s", osname);
+ return (0);
+ }
+
+ zilog = dmu_objset_zil(os);
+ bp = (blkptr_t *)&zilog->zl_header->zh_log;
+
+ /*
+ * Check the first block and determine if it's on a log device
+ * which may have been removed or faulted prior to loading this
+ * pool. If so, there's no point in checking the rest of the log
+ * as its content should have already been synced to the pool.
+ */
+ if (!BP_IS_HOLE(bp)) {
+ vdev_t *vd;
+ boolean_t valid = B_TRUE;
+
+ spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
+ vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
+ if (vd->vdev_islog && vdev_is_dead(vd))
+ valid = vdev_log_state_valid(vd);
+ spa_config_exit(os->os_spa, SCL_STATE, FTAG);
+
+ if (!valid) {
+ dmu_objset_rele(os, FTAG);
+ return (0);
+ }
+ }
+
+ /*
+ * Because tx == NULL, zil_claim_log_block() will not actually claim
+ * any blocks, but just determine whether it is possible to do so.
+ * In addition to checking the log chain, zil_claim_log_block()
+ * will invoke zio_claim() with a done func of spa_claim_notify(),
+ * which will update spa_max_claim_txg. See spa_load() for details.
+ */
+ error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
+ zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
+
+ dmu_objset_rele(os, FTAG);
+
+ return ((error == ECKSUM || error == ENOENT) ? 0 : error);
+}
+
+static int
+zil_vdev_compare(const void *x1, const void *x2)
+{
+ const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
+ const 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, const 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);
+}
+
+static 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;
+ dmu_tx_t *tx = lwb->lwb_tx;
+
+ ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
+ 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;
+ lwb->lwb_tx = NULL;
+ mutex_exit(&zilog->zl_lock);
+
+ /*
+ * 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.
+ */
+ dmu_tx_commit(tx);
+}
+
+/*
+ * Initialize the io for a log block.
+ */
+static void
+zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
+{
+ zbookmark_t zb;
+
+ SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
+ ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
+ 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, BP_GET_LSIZE(&lwb->lwb_blk),
+ zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE,
+ ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb);
+ }
+}
+
+/*
+ * Define a limited set of intent log block sizes.
+ * These must be a multiple of 4KB. Note only the amount used (again
+ * aligned to 4KB) actually gets written. However, we can't always just
+ * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted.
+ */
+uint64_t zil_block_buckets[] = {
+ 4096, /* non TX_WRITE */
+ 8192+4096, /* data base */
+ 32*1024 + 4096, /* NFS writes */
+ UINT64_MAX
+};
+
+/*
+ * Use the slog as long as the logbias is 'latency' and the current commit size
+ * is less than the limit or the total list size is less than 2X the limit.
+ * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX.
+ */
+uint64_t zil_slog_limit = 1024 * 1024;
+#define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \
+ (((zilog)->zl_cur_used < zil_slog_limit) || \
+ ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1))))
+
+/*
+ * 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 = NULL;
+ zil_chain_t *zilc;
+ spa_t *spa = zilog->zl_spa;
+ blkptr_t *bp;
+ dmu_tx_t *tx;
+ uint64_t txg;
+ uint64_t zil_blksz, wsz;
+ int i, error;
+
+ if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
+ zilc = (zil_chain_t *)lwb->lwb_buf;
+ bp = &zilc->zc_next_blk;
+ } else {
+ zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
+ bp = &zilc->zc_next_blk;
+ }
+
+ ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
+
+ /*
+ * 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 dmu_tx_commit() until zil_lwb_write_done().
+ * We dirty the dataset to ensure that zil_sync() will be called
+ * to clean up in the event of allocation failure or I/O failure.
+ */
+ tx = dmu_tx_create(zilog->zl_os);
+ VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
+ dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
+ txg = dmu_tx_get_txg(tx);
+
+ lwb->lwb_tx = tx;
+
+ /*
+ * Log blocks are pre-allocated. Here we select the size of the next
+ * block, based on size used in the last block.
+ * - first find the smallest bucket that will fit the block from a
+ * limited set of block sizes. This is because it's faster to write
+ * blocks allocated from the same metaslab as they are adjacent or
+ * close.
+ * - next find the maximum from the new suggested size and an array of
+ * previous sizes. This lessens a picket fence effect of wrongly
+ * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
+ * requests.
+ *
+ * Note we only write what is used, but we can't just allocate
+ * the maximum block size because we can exhaust the available
+ * pool log space.
+ */
+ zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
+ for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
+ continue;
+ zil_blksz = zil_block_buckets[i];
+ if (zil_blksz == UINT64_MAX)
+ zil_blksz = SPA_MAXBLOCKSIZE;
+ zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
+ for (i = 0; i < ZIL_PREV_BLKS; i++)
+ zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
+ zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
+
+ BP_ZERO(bp);
+ /* pass the old blkptr in order to spread log blocks across devs */
+ error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz,
+ USE_SLOG(zilog));
+ if (!error) {
+ ASSERT3U(bp->blk_birth, ==, txg);
+ bp->blk_cksum = lwb->lwb_blk.blk_cksum;
+ bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
+
+ /*
+ * Allocate a new log write buffer (lwb).
+ */
+ nlwb = zil_alloc_lwb(zilog, bp, txg);
+
+ /* Record the block for later vdev flushing */
+ zil_add_block(zilog, &lwb->lwb_blk);
+ }
+
+ if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
+ /* For Slim ZIL only write what is used. */
+ wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
+ ASSERT3U(wsz, <=, lwb->lwb_sz);
+ zio_shrink(lwb->lwb_zio, wsz);
+
+ } else {
+ wsz = lwb->lwb_sz;
+ }
+
+ zilc->zc_pad = 0;
+ zilc->zc_nused = lwb->lwb_nused;
+ zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
+
+ /*
+ * clear unused data for security
+ */
+ bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
+
+ zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
+
+ /*
+ * If there was an allocation failure then nlwb will be null which
+ * forces a txg_wait_synced().
+ */
+ 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 *lrw = (lr_write_t *)lrc;
+ char *lr_buf;
+ uint64_t txg = lrc->lrc_txg;
+ uint64_t reclen = lrc->lrc_reclen;
+ uint64_t dlen = 0;
+
+ 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(
+ lrw->lr_length, sizeof (uint64_t), uint64_t);
+
+ 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 > lwb->lwb_sz) {
+ lwb = zil_lwb_write_start(zilog, lwb);
+ if (lwb == NULL)
+ return (NULL);
+ zil_lwb_write_init(zilog, lwb);
+ ASSERT(LWB_EMPTY(lwb));
+ if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
+ txg_wait_synced(zilog->zl_dmu_pool, txg);
+ return (lwb);
+ }
+ }
+
+ lr_buf = lwb->lwb_buf + lwb->lwb_nused;
+ bcopy(lrc, lr_buf, reclen);
+ lrc = (lr_t *)lr_buf;
+ lrw = (lr_write_t *)lrc;
+
+ /*
+ * 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;
+
+ if (dlen) {
+ ASSERT(itx->itx_wr_state == WR_NEED_COPY);
+ dbuf = lr_buf + reclen;
+ lrw->lr_common.lrc_reclen += dlen;
+ } else {
+ ASSERT(itx->itx_wr_state == WR_INDIRECT);
+ dbuf = NULL;
+ }
+ error = zilog->zl_get_data(
+ itx->itx_private, lrw, 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);
+ }
+ }
+ }
+
+ /*
+ * We're actually making an entry, so update lrc_seq to be the
+ * log record sequence number. Note that this is generally not
+ * equal to the itx sequence number because not all transactions
+ * are synchronous, and sometimes spa_sync() gets there first.
+ */
+ lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
+ lwb->lwb_nused += reclen + dlen;
+ lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
+ ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
+ 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 */
+ itx->itx_sync = B_TRUE; /* default is synchronous */
+
+ return (itx);
+}
+
+void
+zil_itx_destroy(itx_t *itx)
+{
+ kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen);
+}
+
+/*
+ * Free up the sync and async itxs. The itxs_t has already been detached
+ * so no locks are needed.
+ */
+static void
+zil_itxg_clean(itxs_t *itxs)
+{
+ itx_t *itx;
+ list_t *list;
+ avl_tree_t *t;
+ void *cookie;
+ itx_async_node_t *ian;
+
+ list = &itxs->i_sync_list;
+ while ((itx = list_head(list)) != NULL) {
+ list_remove(list, itx);
+ kmem_free(itx, offsetof(itx_t, itx_lr) +
+ itx->itx_lr.lrc_reclen);
+ }
+
+ cookie = NULL;
+ t = &itxs->i_async_tree;
+ while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
+ list = &ian->ia_list;
+ while ((itx = list_head(list)) != NULL) {
+ list_remove(list, itx);
+ kmem_free(itx, offsetof(itx_t, itx_lr) +
+ itx->itx_lr.lrc_reclen);
+ }
+ list_destroy(list);
+ kmem_free(ian, sizeof (itx_async_node_t));
+ }
+ avl_destroy(t);
+
+ kmem_free(itxs, sizeof (itxs_t));
+}
+
+static int
+zil_aitx_compare(const void *x1, const void *x2)
+{
+ const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
+ const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
+
+ if (o1 < o2)
+ return (-1);
+ if (o1 > o2)
+ return (1);
+
+ return (0);
+}
+
+/*
+ * Remove all async itx with the given oid.
+ */
+static void
+zil_remove_async(zilog_t *zilog, uint64_t oid)
+{
+ uint64_t otxg, txg;
+ itx_async_node_t *ian;
+ avl_tree_t *t;
+ avl_index_t where;
+ list_t clean_list;
+ itx_t *itx;
+
+ ASSERT(oid != 0);
+ list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
+
+ if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
+ otxg = ZILTEST_TXG;
+ else
+ otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
+
+ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
+ itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
+
+ mutex_enter(&itxg->itxg_lock);
+ if (itxg->itxg_txg != txg) {
+ mutex_exit(&itxg->itxg_lock);
+ continue;
+ }
+
+ /*
+ * Locate the object node and append its list.
+ */
+ t = &itxg->itxg_itxs->i_async_tree;
+ ian = avl_find(t, &oid, &where);
+ if (ian != NULL)
+ list_move_tail(&clean_list, &ian->ia_list);
+ mutex_exit(&itxg->itxg_lock);
+ }
+ 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);
+}
+
+void
+zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
+{
+ uint64_t txg;
+ itxg_t *itxg;
+ itxs_t *itxs, *clean = NULL;
+
+ /*
+ * Object ids can be re-instantiated in the next txg so
+ * remove any async transactions to avoid future leaks.
+ * This can happen if a fsync occurs on the re-instantiated
+ * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
+ * the new file data and flushes a write record for the old object.
+ */
+ if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
+ zil_remove_async(zilog, itx->itx_oid);
+
+ /*
+ * Ensure the data of a renamed file is committed before the rename.
+ */
+ if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
+ zil_async_to_sync(zilog, itx->itx_oid);
+
+ if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
+ txg = ZILTEST_TXG;
+ else
+ txg = dmu_tx_get_txg(tx);
+
+ itxg = &zilog->zl_itxg[txg & TXG_MASK];
+ mutex_enter(&itxg->itxg_lock);
+ itxs = itxg->itxg_itxs;
+ if (itxg->itxg_txg != txg) {
+ if (itxs != NULL) {
+ /*
+ * The zil_clean callback hasn't got around to cleaning
+ * this itxg. Save the itxs for release below.
+ * This should be rare.
+ */
+ atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
+ itxg->itxg_sod = 0;
+ clean = itxg->itxg_itxs;
+ }
+ ASSERT(itxg->itxg_sod == 0);
+ itxg->itxg_txg = txg;
+ itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP);
+
+ list_create(&itxs->i_sync_list, sizeof (itx_t),
+ offsetof(itx_t, itx_node));
+ avl_create(&itxs->i_async_tree, zil_aitx_compare,
+ sizeof (itx_async_node_t),
+ offsetof(itx_async_node_t, ia_node));
+ }
+ if (itx->itx_sync) {
+ list_insert_tail(&itxs->i_sync_list, itx);
+ atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
+ itxg->itxg_sod += itx->itx_sod;
+ } else {
+ avl_tree_t *t = &itxs->i_async_tree;
+ uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid;
+ itx_async_node_t *ian;
+ avl_index_t where;
+
+ ian = avl_find(t, &foid, &where);
+ if (ian == NULL) {
+ ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP);
+ list_create(&ian->ia_list, sizeof (itx_t),
+ offsetof(itx_t, itx_node));
+ ian->ia_foid = foid;
+ avl_insert(t, ian, where);
+ }
+ list_insert_tail(&ian->ia_list, itx);
+ }
+
+ itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
+ mutex_exit(&itxg->itxg_lock);
+
+ /* Release the old itxs now we've dropped the lock */
+ if (clean != NULL)
+ zil_itxg_clean(clean);
+}
+
+/*
+ * 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, uint64_t synced_txg)
+{
+ itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
+ itxs_t *clean_me;
+
+ mutex_enter(&itxg->itxg_lock);
+ if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
+ mutex_exit(&itxg->itxg_lock);
+ return;
+ }
+ ASSERT3U(itxg->itxg_txg, <=, synced_txg);
+ ASSERT(itxg->itxg_txg != 0);
+ ASSERT(zilog->zl_clean_taskq != NULL);
+ atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
+ itxg->itxg_sod = 0;
+ clean_me = itxg->itxg_itxs;
+ itxg->itxg_itxs = NULL;
+ itxg->itxg_txg = 0;
+ mutex_exit(&itxg->itxg_lock);
+ /*
+ * Preferably start a task queue to free up the old itxs but
+ * if taskq_dispatch can't allocate resources to do that then
+ * free it in-line. This should be rare. Note, using TQ_SLEEP
+ * created a bad performance problem.
+ */
+ if (taskq_dispatch(zilog->zl_clean_taskq,
+ (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL)
+ zil_itxg_clean(clean_me);
+}
+
+/*
+ * Get the list of itxs to commit into zl_itx_commit_list.
+ */
+static void
+zil_get_commit_list(zilog_t *zilog)
+{
+ uint64_t otxg, txg;
+ list_t *commit_list = &zilog->zl_itx_commit_list;
+ uint64_t push_sod = 0;
+
+ if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
+ otxg = ZILTEST_TXG;
+ else
+ otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
+
+ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
+ itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
+
+ mutex_enter(&itxg->itxg_lock);
+ if (itxg->itxg_txg != txg) {
+ mutex_exit(&itxg->itxg_lock);
+ continue;
+ }
+
+ list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
+ push_sod += itxg->itxg_sod;
+ itxg->itxg_sod = 0;
+
+ mutex_exit(&itxg->itxg_lock);
+ }
+ atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
+}
+
+/*
+ * Move the async itxs for a specified object to commit into sync lists.
+ */
+static void
+zil_async_to_sync(zilog_t *zilog, uint64_t foid)
+{
+ uint64_t otxg, txg;
+ itx_async_node_t *ian;
+ avl_tree_t *t;
+ avl_index_t where;
+
+ if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
+ otxg = ZILTEST_TXG;
+ else
+ otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
+
+ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
+ itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
+
+ mutex_enter(&itxg->itxg_lock);
+ if (itxg->itxg_txg != txg) {
+ mutex_exit(&itxg->itxg_lock);
+ continue;
+ }
+
+ /*
+ * If a foid is specified then find that node and append its
+ * list. Otherwise walk the tree appending all the lists
+ * to the sync list. We add to the end rather than the
+ * beginning to ensure the create has happened.
+ */
+ t = &itxg->itxg_itxs->i_async_tree;
+ if (foid != 0) {
+ ian = avl_find(t, &foid, &where);
+ if (ian != NULL) {
+ list_move_tail(&itxg->itxg_itxs->i_sync_list,
+ &ian->ia_list);
+ }
+ } else {
+ void *cookie = NULL;
+
+ while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
+ list_move_tail(&itxg->itxg_itxs->i_sync_list,
+ &ian->ia_list);
+ list_destroy(&ian->ia_list);
+ kmem_free(ian, sizeof (itx_async_node_t));
+ }
+ }
+ mutex_exit(&itxg->itxg_lock);
+ }
+}
+
+static void
+zil_commit_writer(zilog_t *zilog)
+{
+ uint64_t txg;
+ itx_t *itx;
+ lwb_t *lwb;
+ spa_t *spa = zilog->zl_spa;
+ int error = 0;
+
+ ASSERT(zilog->zl_root_zio == NULL);
+
+ mutex_exit(&zilog->zl_lock);
+
+ zil_get_commit_list(zilog);
+
+ /*
+ * Return if there's nothing to commit before we dirty the fs by
+ * calling zil_create().
+ */
+ if (list_head(&zilog->zl_itx_commit_list) == NULL) {
+ mutex_enter(&zilog->zl_lock);
+ return;
+ }
+
+ if (zilog->zl_suspend) {
+ lwb = NULL;
+ } else {
+ lwb = list_tail(&zilog->zl_lwb_list);
+ if (lwb == NULL)
+ lwb = zil_create(zilog);
+ }
+
+ DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
+ while (itx = list_head(&zilog->zl_itx_commit_list)) {
+ 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);
+ list_remove(&zilog->zl_itx_commit_list, itx);
+ kmem_free(itx, offsetof(itx_t, itx_lr)
+ + itx->itx_lr.lrc_reclen);
+ }
+ DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
+
+ /* write the last block out */
+ if (lwb != NULL && lwb->lwb_zio != NULL)
+ lwb = zil_lwb_write_start(zilog, lwb);
+
+ zilog->zl_cur_used = 0;
+
+ /*
+ * Wait if necessary for the log blocks to be on stable storage.
+ */
+ if (zilog->zl_root_zio) {
+ error = zio_wait(zilog->zl_root_zio);
+ zilog->zl_root_zio = NULL;
+ zil_flush_vdevs(zilog);
+ }
+
+ if (error || lwb == NULL)
+ txg_wait_synced(zilog->zl_dmu_pool, 0);
+
+ mutex_enter(&zilog->zl_lock);
+
+ /*
+ * Remember the highest committed log sequence number for ztest.
+ * We only update this value when all the log writes succeeded,
+ * because ztest wants to ASSERT that it got the whole log chain.
+ */
+ if (error == 0 && lwb != NULL)
+ zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
+}
+
+/*
+ * Commit zfs transactions to stable storage.
+ * If foid is 0 push out all transactions, otherwise push only those
+ * for that object or might reference that object.
+ *
+ * itxs are committed in batches. In a heavily stressed zil there will be
+ * a commit writer thread who is writing out a bunch of itxs to the log
+ * for a set of committing threads (cthreads) in the same batch as the writer.
+ * Those cthreads are all waiting on the same cv for that batch.
+ *
+ * There will also be a different and growing batch of threads that are
+ * waiting to commit (qthreads). When the committing batch completes
+ * a transition occurs such that the cthreads exit and the qthreads become
+ * cthreads. One of the new cthreads becomes the writer thread for the
+ * batch. Any new threads arriving become new qthreads.
+ *
+ * Only 2 condition variables are needed and there's no transition
+ * between the two cvs needed. They just flip-flop between qthreads
+ * and cthreads.
+ *
+ * Using this scheme we can efficiently wakeup up only those threads
+ * that have been committed.
+ */
+void
+zil_commit(zilog_t *zilog, uint64_t foid)
+{
+ uint64_t mybatch;
+
+ if (zilog->zl_sync == ZFS_SYNC_DISABLED)
+ return;
+
+ /* move the async itxs for the foid to the sync queues */
+ zil_async_to_sync(zilog, foid);
+
+ mutex_enter(&zilog->zl_lock);
+ mybatch = zilog->zl_next_batch;
+ while (zilog->zl_writer) {
+ cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
+ if (mybatch <= zilog->zl_com_batch) {
+ mutex_exit(&zilog->zl_lock);
+ return;
+ }
+ }
+
+ zilog->zl_next_batch++;
+ zilog->zl_writer = B_TRUE;
+ zil_commit_writer(zilog);
+ zilog->zl_com_batch = mybatch;
+ zilog->zl_writer = B_FALSE;
+ mutex_exit(&zilog->zl_lock);
+
+ /* wake up one thread to become the next writer */
+ cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
+
+ /* wake up all threads waiting for this batch to be committed */
+ cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
+}
+
+/*
+ * 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;
+ uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
+ 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);
+
+ if (*replayed_seq != 0) {
+ ASSERT(zh->zh_replay_seq < *replayed_seq);
+ zh->zh_replay_seq = *replayed_seq;
+ *replayed_seq = 0;
+ }
+
+ 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_zil(spa, txg, &lwb->lwb_blk);
+ 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);
+}
+
+void
+zil_set_sync(zilog_t *zilog, uint64_t sync)
+{
+ zilog->zl_sync = sync;
+}
+
+void
+zil_set_logbias(zilog_t *zilog, uint64_t logbias)
+{
+ zilog->zl_logbias = logbias;
+}
+
+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;
+ zilog->zl_logbias = dmu_objset_logbias(os);
+ zilog->zl_sync = dmu_objset_syncprop(os);
+ zilog->zl_next_batch = 1;
+
+ mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
+
+ for (int i = 0; i < TXG_SIZE; i++) {
+ mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
+ MUTEX_DEFAULT, NULL);
+ }
+
+ list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
+ offsetof(lwb_t, lwb_node));
+
+ list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
+ offsetof(itx_t, itx_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);
+ cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
+ cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
+
+ return (zilog);
+}
+
+void
+zil_free(zilog_t *zilog)
+{
+ lwb_t *head_lwb;
+
+ zilog->zl_stop_sync = 1;
+
+ /*
+ * After zil_close() there should only be one lwb with a buffer.
+ */
+ head_lwb = list_head(&zilog->zl_lwb_list);
+ if (head_lwb) {
+ ASSERT(head_lwb == list_tail(&zilog->zl_lwb_list));
+ list_remove(&zilog->zl_lwb_list, head_lwb);
+ zio_buf_free(head_lwb->lwb_buf, head_lwb->lwb_sz);
+ kmem_cache_free(zil_lwb_cache, head_lwb);
+ }
+ list_destroy(&zilog->zl_lwb_list);
+
+ avl_destroy(&zilog->zl_vdev_tree);
+ mutex_destroy(&zilog->zl_vdev_lock);
+
+ ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
+ list_destroy(&zilog->zl_itx_commit_list);
+
+ for (int i = 0; i < TXG_SIZE; i++) {
+ /*
+ * It's possible for an itx to be generated that doesn't dirty
+ * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
+ * callback to remove the entry. We remove those here.
+ *
+ * Also free up the ziltest itxs.
+ */
+ if (zilog->zl_itxg[i].itxg_itxs)
+ zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
+ mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
+ }
+
+ mutex_destroy(&zilog->zl_lock);
+
+ cv_destroy(&zilog->zl_cv_writer);
+ cv_destroy(&zilog->zl_cv_suspend);
+ cv_destroy(&zilog->zl_cv_batch[0]);
+ cv_destroy(&zilog->zl_cv_batch[1]);
+
+ 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)
+{
+ lwb_t *tail_lwb;
+ uint64_t txg = 0;
+
+ zil_commit(zilog, 0); /* commit all itx */
+
+ /*
+ * The lwb_max_txg for the stubby lwb will reflect the last activity
+ * for the zil. After a txg_wait_synced() on the txg we know all the
+ * callbacks have occurred that may clean the zil. Only then can we
+ * destroy the zl_clean_taskq.
+ */
+ mutex_enter(&zilog->zl_lock);
+ tail_lwb = list_tail(&zilog->zl_lwb_list);
+ if (tail_lwb != NULL)
+ txg = tail_lwb->lwb_max_txg;
+ mutex_exit(&zilog->zl_lock);
+ if (txg)
+ txg_wait_synced(zilog->zl_dmu_pool, txg);
+
+ taskq_destroy(zilog->zl_clean_taskq);
+ zilog->zl_clean_taskq = NULL;
+ zilog->zl_get_data = 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, 0);
+
+ 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 {
+ zil_replay_func_t **zr_replay;
+ void *zr_arg;
+ boolean_t zr_byteswap;
+ char *zr_lr;
+} zil_replay_arg_t;
+
+static int
+zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
+{
+ char name[MAXNAMELEN];
+
+ zilog->zl_replaying_seq--; /* didn't actually replay this one */
+
+ dmu_objset_name(zilog->zl_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)(lr->lrc_txtype & ~TX_CI),
+ (lr->lrc_txtype & TX_CI) ? "CI" : "");
+
+ return (error);
+}
+
+static int
+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;
+ int error = 0;
+
+ zilog->zl_replaying_seq = lr->lrc_seq;
+
+ if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
+ return (0);
+
+ if (lr->lrc_txg < claim_txg) /* already committed */
+ return (0);
+
+ /* Strip case-insensitive bit, still present in log record */
+ txtype &= ~TX_CI;
+
+ if (txtype == 0 || txtype >= TX_MAX_TYPE)
+ return (zil_replay_error(zilog, lr, EINVAL));
+
+ /*
+ * If this record type can be logged out of order, the object
+ * (lr_foid) may no longer exist. That's legitimate, not an error.
+ */
+ if (TX_OOO(txtype)) {
+ error = dmu_object_info(zilog->zl_os,
+ ((lr_ooo_t *)lr)->lr_foid, NULL);
+ if (error == ENOENT || error == EEXIST)
+ return (0);
+ }
+
+ /*
+ * Make a copy of the data so we can revise and extend it.
+ */
+ bcopy(lr, zr->zr_lr, reclen);
+
+ /*
+ * If this is a TX_WRITE with a blkptr, suck in the data.
+ */
+ if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
+ error = zil_read_log_data(zilog, (lr_write_t *)lr,
+ zr->zr_lr + reclen);
+ if (error)
+ return (zil_replay_error(zilog, lr, error));
+ }
+
+ /*
+ * 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 record 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_lr, reclen);
+
+ /*
+ * 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.
+ */
+ error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
+ if (error) {
+ /*
+ * 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. Note that we
+ * specify B_FALSE for byteswap now, so we don't do it twice.
+ */
+ txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
+ error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
+ if (error)
+ return (zil_replay_error(zilog, lr, error));
+ }
+ return (0);
+}
+
+/* ARGSUSED */
+static int
+zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
+{
+ zilog->zl_replay_blks++;
+
+ return (0);
+}
+
+/*
+ * 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_replay = replay_func;
+ zr.zr_arg = arg;
+ zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
+ zr.zr_lr = kmem_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 = ddi_get_lbolt();
+ ASSERT(zilog->zl_replay_blks == 0);
+ (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
+ zh->zh_claim_txg);
+ kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
+
+ zil_destroy(zilog, B_FALSE);
+ txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
+ zilog->zl_replay = B_FALSE;
+}
+
+boolean_t
+zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
+{
+ if (zilog->zl_sync == ZFS_SYNC_DISABLED)
+ return (B_TRUE);
+
+ if (zilog->zl_replay) {
+ dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
+ zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
+ zilog->zl_replaying_seq;
+ return (B_TRUE);
+ }
+
+ return (B_FALSE);
+}
+
+/* ARGSUSED */
+int
+zil_vdev_offline(const char *osname, void *arg)
+{
+ objset_t *os;
+ zilog_t *zilog;
+ int error;
+
+ error = dmu_objset_hold(osname, FTAG, &os);
+ if (error)
+ return (error);
+
+ zilog = dmu_objset_zil(os);
+ if (zil_suspend(zilog) != 0)
+ error = EEXIST;
+ else
+ zil_resume(zilog);
+ dmu_objset_rele(os, FTAG);
+ return (error);
+}