diff options
Diffstat (limited to 'uts/common/fs/zfs/zil.c')
| -rw-r--r-- | uts/common/fs/zfs/zil.c | 1992 |
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); +} |