/* * 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 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" #include #include #include #include #include #include #include #include #include #include #include /* * 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: */ /* * These global ZIL switches affect all pools */ int zil_disable = 0; /* disable intent logging */ int zil_always = 0; /* make every transaction synchronous */ int zil_purge = 0; /* at pool open, just throw everything away */ int zil_noflush = 0; /* don't flush write cache buffers on disks */ static kmem_cache_t *zil_lwb_cache; static int zil_dva_compare(const void *x1, const void *x2) { const dva_t *dva1 = x1; const dva_t *dva2 = x2; if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) return (-1); if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) return (1); if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) return (-1); if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) return (1); return (0); } static void zil_dva_tree_init(avl_tree_t *t) { avl_create(t, zil_dva_compare, sizeof (zil_dva_node_t), offsetof(zil_dva_node_t, zn_node)); } static void zil_dva_tree_fini(avl_tree_t *t) { zil_dva_node_t *zn; void *cookie = NULL; while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) kmem_free(zn, sizeof (zil_dva_node_t)); avl_destroy(t); } static int zil_dva_tree_add(avl_tree_t *t, dva_t *dva) { zil_dva_node_t *zn; avl_index_t where; if (avl_find(t, dva, &where) != NULL) return (EEXIST); zn = kmem_alloc(sizeof (zil_dva_node_t), KM_SLEEP); zn->zn_dva = *dva; avl_insert(t, zn, where); return (0); } /* * Read a log block, make sure it's valid, and byteswap it if necessary. */ static int zil_read_log_block(zilog_t *zilog, blkptr_t *bp, char *buf) { uint64_t blksz = BP_GET_LSIZE(bp); zil_trailer_t *ztp = (zil_trailer_t *)(buf + blksz) - 1; zio_cksum_t cksum; zbookmark_t zb; int error; zb.zb_objset = bp->blk_cksum.zc_word[2]; zb.zb_object = 0; zb.zb_level = -1; zb.zb_blkid = bp->blk_cksum.zc_word[3]; error = zio_wait(zio_read(NULL, zilog->zl_spa, bp, buf, blksz, NULL, NULL, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb)); if (error) { dprintf_bp(bp, "zilog %p bp %p read failed, error %d: ", zilog, bp, error); return (error); } if (BP_SHOULD_BYTESWAP(bp)) byteswap_uint64_array(buf, blksz); /* * Sequence numbers should be... sequential. The checksum verifier for * the next block should be: . */ cksum = bp->blk_cksum; cksum.zc_word[3]++; if (bcmp(&cksum, &ztp->zit_next_blk.blk_cksum, sizeof (cksum)) != 0) { dprintf_bp(bp, "zilog %p bp %p stale pointer: ", zilog, bp); return (ESTALE); } if (BP_IS_HOLE(&ztp->zit_next_blk)) { dprintf_bp(bp, "zilog %p bp %p hole: ", zilog, bp); return (ENOENT); } if (ztp->zit_nused > (blksz - sizeof (zil_trailer_t))) { dprintf("zilog %p bp %p nused exceeds blksz\n", zilog, bp); return (EOVERFLOW); } dprintf_bp(bp, "zilog %p bp %p good block: ", zilog, bp); return (0); } /* * Parse the intent log, and call parse_func for each valid record within. */ void 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) { blkptr_t blk; char *lrbuf, *lrp; zil_trailer_t *ztp; int reclen, error; blk = zilog->zl_header->zh_log; if (BP_IS_HOLE(&blk)) return; /* * 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(). */ zil_dva_tree_init(&zilog->zl_dva_tree); lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); for (;;) { error = zil_read_log_block(zilog, &blk, lrbuf); if (parse_blk_func != NULL) parse_blk_func(zilog, &blk, arg, txg); if (error) break; ztp = (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1; blk = ztp->zit_next_blk; if (parse_lr_func == NULL) continue; for (lrp = lrbuf; lrp < lrbuf + ztp->zit_nused; lrp += reclen) { lr_t *lr = (lr_t *)lrp; reclen = lr->lrc_reclen; ASSERT3U(reclen, >=, sizeof (lr_t)); parse_lr_func(zilog, lr, arg, txg); } } zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); zil_dva_tree_fini(&zilog->zl_dva_tree); } /* ARGSUSED */ static void zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) { spa_t *spa = zilog->zl_spa; int err; dprintf_bp(bp, "first_txg %llu: ", first_txg); /* * Claim log block if not already committed and not already claimed. */ if (bp->blk_birth >= first_txg && zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp)) == 0) { err = zio_wait(zio_claim(NULL, spa, first_txg, bp, NULL, NULL)); ASSERT(err == 0); } } static void zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) { if (lrc->lrc_txtype == TX_WRITE) { lr_write_t *lr = (lr_write_t *)lrc; zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg); } } /* ARGSUSED */ static void zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) { zio_free_blk(zilog->zl_spa, bp, dmu_tx_get_txg(tx)); } static void zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) { /* * If we previously claimed it, we need to free it. */ if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE) { lr_write_t *lr = (lr_write_t *)lrc; blkptr_t *bp = &lr->lr_blkptr; if (bp->blk_birth >= claim_txg && !zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp))) { (void) arc_free(NULL, zilog->zl_spa, dmu_tx_get_txg(tx), bp, NULL, NULL, ARC_WAIT); } } } /* * Create an on-disk intent log. */ static void zil_create(zilog_t *zilog) { lwb_t *lwb; uint64_t txg; dmu_tx_t *tx; blkptr_t blk; int error; int no_blk; ASSERT(zilog->zl_header->zh_claim_txg == 0); ASSERT(zilog->zl_header->zh_replay_seq == 0); /* * Initialize the log header block. */ tx = dmu_tx_create(zilog->zl_os); (void) dmu_tx_assign(tx, TXG_WAIT); dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); txg = dmu_tx_get_txg(tx); /* * If we don't have a log block already then * allocate the first log block and assign its checksum verifier. */ no_blk = BP_IS_HOLE(&zilog->zl_header->zh_log); if (no_blk) { error = zio_alloc_blk(zilog->zl_spa, ZIO_CHECKSUM_ZILOG, ZIL_MIN_BLKSZ, &blk, txg); } else { blk = zilog->zl_header->zh_log; error = 0; } if (error == 0) { ZIO_SET_CHECKSUM(&blk.blk_cksum, spa_get_random(-1ULL), spa_get_random(-1ULL), dmu_objset_id(zilog->zl_os), 1ULL); /* * Allocate a log write buffer (lwb) for the first log block. */ lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); lwb->lwb_zilog = zilog; lwb->lwb_blk = blk; lwb->lwb_nused = 0; lwb->lwb_sz = BP_GET_LSIZE(&lwb->lwb_blk); lwb->lwb_buf = zio_buf_alloc(lwb->lwb_sz); lwb->lwb_max_txg = txg; lwb->lwb_seq = 0; lwb->lwb_state = UNWRITTEN; mutex_enter(&zilog->zl_lock); list_insert_tail(&zilog->zl_lwb_list, lwb); mutex_exit(&zilog->zl_lock); } dmu_tx_commit(tx); if (no_blk) txg_wait_synced(zilog->zl_dmu_pool, txg); } /* * In one tx, free all log blocks and clear the log header. */ void zil_destroy(zilog_t *zilog) { dmu_tx_t *tx; uint64_t txg; mutex_enter(&zilog->zl_destroy_lock); if (BP_IS_HOLE(&zilog->zl_header->zh_log)) { mutex_exit(&zilog->zl_destroy_lock); return; } tx = dmu_tx_create(zilog->zl_os); (void) dmu_tx_assign(tx, TXG_WAIT); dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); txg = dmu_tx_get_txg(tx); zil_parse(zilog, zil_free_log_block, zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); /* * zil_sync clears the zil header as soon as the zl_destroy_txg commits */ zilog->zl_destroy_txg = txg; dmu_tx_commit(tx); txg_wait_synced(zilog->zl_dmu_pool, txg); mutex_exit(&zilog->zl_destroy_lock); } void zil_claim(char *osname, void *txarg) { dmu_tx_t *tx = txarg; uint64_t first_txg = dmu_tx_get_txg(tx); zilog_t *zilog; zil_header_t *zh; objset_t *os; int error; error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_STANDARD, &os); if (error) { cmn_err(CE_WARN, "can't process intent log for %s", osname); return; } zilog = dmu_objset_zil(os); zh = zilog->zl_header; /* * Claim all log blocks if we haven't already done so. */ ASSERT3U(zh->zh_claim_txg, <=, first_txg); if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { zh->zh_claim_txg = first_txg; zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, first_txg); dsl_dataset_dirty(dmu_objset_ds(os), tx); } ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); dmu_objset_close(os); } void zil_add_vdev(zilog_t *zilog, uint64_t vdev, uint64_t seq) { zil_vdev_t *zv; if (zil_noflush) return; ASSERT(MUTEX_HELD(&zilog->zl_lock)); zv = kmem_alloc(sizeof (zil_vdev_t), KM_SLEEP); zv->vdev = vdev; zv->seq = seq; list_insert_tail(&zilog->zl_vdev_list, zv); } void zil_flush_vdevs(zilog_t *zilog, uint64_t seq) { vdev_t *vd; zil_vdev_t *zv, *zv2; zio_t *zio; spa_t *spa; uint64_t vdev; if (zil_noflush) return; ASSERT(MUTEX_HELD(&zilog->zl_lock)); spa = zilog->zl_spa; zio = NULL; while ((zv = list_head(&zilog->zl_vdev_list)) != NULL && zv->seq <= seq) { vdev = zv->vdev; list_remove(&zilog->zl_vdev_list, zv); kmem_free(zv, sizeof (zil_vdev_t)); /* * remove all chained entries <= seq with same vdev */ zv = list_head(&zilog->zl_vdev_list); while (zv && zv->seq <= seq) { zv2 = list_next(&zilog->zl_vdev_list, zv); if (zv->vdev == vdev) { list_remove(&zilog->zl_vdev_list, zv); kmem_free(zv, sizeof (zil_vdev_t)); } zv = zv2; } /* flush the write cache for this vdev */ mutex_exit(&zilog->zl_lock); if (zio == NULL) zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); vd = vdev_lookup_top(spa, vdev); ASSERT(vd); (void) zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, NULL, NULL, ZIO_PRIORITY_NOW, ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); mutex_enter(&zilog->zl_lock); } /* * Wait for all the flushes to complete. Not all devices actually * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. */ if (zio != NULL) { mutex_exit(&zilog->zl_lock); (void) zio_wait(zio); mutex_enter(&zilog->zl_lock); } } /* * Function called when a log block write completes */ static void zil_lwb_write_done(zio_t *zio) { lwb_t *prev; lwb_t *lwb = zio->io_private; zilog_t *zilog = lwb->lwb_zilog; uint64_t max_seq; /* * 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. */ txg_rele_to_sync(&lwb->lwb_txgh); zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); mutex_enter(&zilog->zl_lock); lwb->lwb_buf = NULL; if (zio->io_error) { zilog->zl_log_error = B_TRUE; mutex_exit(&zilog->zl_lock); cv_broadcast(&zilog->zl_cv_seq); return; } prev = list_prev(&zilog->zl_lwb_list, lwb); if (prev && prev->lwb_state != SEQ_COMPLETE) { /* There's an unwritten buffer in the chain before this one */ lwb->lwb_state = SEQ_INCOMPLETE; mutex_exit(&zilog->zl_lock); return; } max_seq = lwb->lwb_seq; lwb->lwb_state = SEQ_COMPLETE; /* * We must also follow up the chain for already written buffers * to see if we can set zl_ss_seq even higher. */ while (lwb = list_next(&zilog->zl_lwb_list, lwb)) { if (lwb->lwb_state != SEQ_INCOMPLETE) break; lwb->lwb_state = SEQ_COMPLETE; /* lwb_seq will be zero if we've written an empty buffer */ if (lwb->lwb_seq) { ASSERT3U(max_seq, <, lwb->lwb_seq); max_seq = lwb->lwb_seq; } } zilog->zl_ss_seq = MAX(max_seq, zilog->zl_ss_seq); mutex_exit(&zilog->zl_lock); cv_broadcast(&zilog->zl_cv_seq); } /* * Start a log block write and advance to the next log block. * Calls are serialized. */ static lwb_t * zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) { lwb_t *nlwb; zil_trailer_t *ztp = (zil_trailer_t *)(lwb->lwb_buf + lwb->lwb_sz) - 1; uint64_t txg; uint64_t zil_blksz; zbookmark_t zb; int error; ASSERT(lwb->lwb_nused <= ZIL_BLK_DATA_SZ(lwb)); /* * Allocate the next block and save its address in this block * before writing it in order to establish the log chain. * Note that if the allocation of nlwb synced before we wrote * the block that points at it (lwb), we'd leak it if we crashed. * Therefore, we don't do txg_rele_to_sync() until zil_lwb_write_done(). */ txg = txg_hold_open(zilog->zl_dmu_pool, &lwb->lwb_txgh); txg_rele_to_quiesce(&lwb->lwb_txgh); /* * Pick a ZIL blocksize. We request a size that is the * maximum of the previous used size, the current used size and * the amount waiting in the queue. */ zil_blksz = MAX(zilog->zl_cur_used, zilog->zl_prev_used); zil_blksz = MAX(zil_blksz, zilog->zl_itx_list_sz + sizeof (*ztp)); zil_blksz = P2ROUNDUP(zil_blksz, ZIL_MIN_BLKSZ); if (zil_blksz > ZIL_MAX_BLKSZ) zil_blksz = ZIL_MAX_BLKSZ; error = zio_alloc_blk(zilog->zl_spa, ZIO_CHECKSUM_ZILOG, zil_blksz, &ztp->zit_next_blk, txg); if (error) { /* * Reinitialise the lwb. * By returning NULL the caller will call tx_wait_synced() */ mutex_enter(&zilog->zl_lock); ASSERT(lwb->lwb_state == UNWRITTEN); lwb->lwb_nused = 0; lwb->lwb_seq = 0; mutex_exit(&zilog->zl_lock); txg_rele_to_sync(&lwb->lwb_txgh); return (NULL); } ASSERT3U(ztp->zit_next_blk.blk_birth, ==, txg); ztp->zit_pad = 0; ztp->zit_nused = lwb->lwb_nused; ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum; ztp->zit_next_blk.blk_cksum = lwb->lwb_blk.blk_cksum; ztp->zit_next_blk.blk_cksum.zc_word[3]++; /* * Allocate a new log write buffer (lwb). */ nlwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); nlwb->lwb_zilog = zilog; nlwb->lwb_blk = ztp->zit_next_blk; nlwb->lwb_nused = 0; nlwb->lwb_sz = BP_GET_LSIZE(&nlwb->lwb_blk); nlwb->lwb_buf = zio_buf_alloc(nlwb->lwb_sz); nlwb->lwb_max_txg = txg; nlwb->lwb_seq = 0; nlwb->lwb_state = UNWRITTEN; /* * Put new lwb at the end of the log chain, * and record the vdev for later flushing */ mutex_enter(&zilog->zl_lock); list_insert_tail(&zilog->zl_lwb_list, nlwb); zil_add_vdev(zilog, DVA_GET_VDEV(BP_IDENTITY(&(lwb->lwb_blk))), lwb->lwb_seq); mutex_exit(&zilog->zl_lock); /* * write the old log block */ dprintf_bp(&lwb->lwb_blk, "lwb %p txg %llu: ", lwb, txg); zb.zb_objset = lwb->lwb_blk.blk_cksum.zc_word[2]; zb.zb_object = 0; zb.zb_level = -1; zb.zb_blkid = lwb->lwb_blk.blk_cksum.zc_word[3]; zio_nowait(zio_rewrite(NULL, zilog->zl_spa, ZIO_CHECKSUM_ZILOG, 0, &lwb->lwb_blk, lwb->lwb_buf, lwb->lwb_sz, zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb)); 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 */ uint64_t seq = lrc->lrc_seq; uint64_t txg = lrc->lrc_txg; uint64_t reclen = lrc->lrc_reclen; int error; if (lwb == NULL) return (NULL); ASSERT(lwb->lwb_buf != NULL); /* * If it's a write, fetch the data or get its blkptr as appropriate. */ if (lrc->lrc_txtype == TX_WRITE) { lr_write_t *lr = (lr_write_t *)lrc; if (txg > spa_freeze_txg(zilog->zl_spa)) txg_wait_synced(zilog->zl_dmu_pool, txg); if (!itx->itx_data_copied && (error = zilog->zl_get_data(itx->itx_private, lr)) != 0) { if (error != ENOENT && error != EALREADY) { txg_wait_synced(zilog->zl_dmu_pool, txg); mutex_enter(&zilog->zl_lock); zilog->zl_ss_seq = MAX(seq, zilog->zl_ss_seq); zil_add_vdev(zilog, DVA_GET_VDEV(BP_IDENTITY(&(lr->lr_blkptr))), seq); mutex_exit(&zilog->zl_lock); return (lwb); } mutex_enter(&zilog->zl_lock); zil_add_vdev(zilog, DVA_GET_VDEV(BP_IDENTITY(&(lr->lr_blkptr))), seq); mutex_exit(&zilog->zl_lock); return (lwb); } } zilog->zl_cur_used += reclen; /* * If this record won't fit in the current log block, start a new one. */ if (lwb->lwb_nused + reclen > ZIL_BLK_DATA_SZ(lwb)) { lwb = zil_lwb_write_start(zilog, lwb); if (lwb == NULL) return (NULL); ASSERT(lwb->lwb_nused == 0); if (reclen > ZIL_BLK_DATA_SZ(lwb)) { txg_wait_synced(zilog->zl_dmu_pool, txg); mutex_enter(&zilog->zl_lock); zilog->zl_ss_seq = MAX(seq, zilog->zl_ss_seq); mutex_exit(&zilog->zl_lock); return (lwb); } } bcopy(lrc, lwb->lwb_buf + lwb->lwb_nused, reclen); lwb->lwb_nused += reclen; lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); ASSERT3U(lwb->lwb_seq, <, seq); lwb->lwb_seq = seq; ASSERT3U(lwb->lwb_nused, <=, ZIL_BLK_DATA_SZ(lwb)); ASSERT3U(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)), ==, 0); return (lwb); } itx_t * zil_itx_create(int txtype, size_t lrsize) { itx_t *itx; lrsize = P2ROUNDUP(lrsize, sizeof (uint64_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_lr.lrc_seq = 0; /* defensive */ return (itx); } uint64_t zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) { uint64_t seq; ASSERT(itx->itx_lr.lrc_seq == 0); mutex_enter(&zilog->zl_lock); list_insert_tail(&zilog->zl_itx_list, itx); zilog->zl_itx_list_sz += itx->itx_lr.lrc_reclen; itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); itx->itx_lr.lrc_seq = seq = ++zilog->zl_itx_seq; mutex_exit(&zilog->zl_lock); return (seq); } /* * Free up all in-memory intent log transactions that have now been synced. */ static void zil_itx_clean(zilog_t *zilog) { uint64_t synced_txg = spa_last_synced_txg(zilog->zl_spa); uint64_t freeze_txg = spa_freeze_txg(zilog->zl_spa); uint64_t max_seq = 0; itx_t *itx; mutex_enter(&zilog->zl_lock); while ((itx = list_head(&zilog->zl_itx_list)) != NULL && itx->itx_lr.lrc_txg <= MIN(synced_txg, freeze_txg)) { list_remove(&zilog->zl_itx_list, itx); zilog->zl_itx_list_sz -= itx->itx_lr.lrc_reclen; ASSERT3U(max_seq, <, itx->itx_lr.lrc_seq); max_seq = itx->itx_lr.lrc_seq; kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); } if (max_seq > zilog->zl_ss_seq) { zilog->zl_ss_seq = max_seq; cv_broadcast(&zilog->zl_cv_seq); } mutex_exit(&zilog->zl_lock); } void zil_clean(zilog_t *zilog) { /* * Check for any log blocks that can be freed. * Log blocks are only freed when the log block allocation and * log records contained within are both known to be committed. */ mutex_enter(&zilog->zl_lock); if (list_head(&zilog->zl_itx_list) != NULL) (void) taskq_dispatch(zilog->zl_clean_taskq, (void (*)(void *))zil_itx_clean, zilog, TQ_NOSLEEP); mutex_exit(&zilog->zl_lock); } /* * Push zfs transactions to stable storage up to the supplied sequence number. */ void zil_commit(zilog_t *zilog, uint64_t seq, int ioflag) { uint64_t txg; uint64_t max_seq; uint64_t reclen; itx_t *itx; lwb_t *lwb; spa_t *spa; if (zilog == NULL || seq == 0 || ((ioflag & (FSYNC | FDSYNC | FRSYNC)) == 0 && !zil_always)) return; spa = zilog->zl_spa; mutex_enter(&zilog->zl_lock); seq = MIN(seq, zilog->zl_itx_seq); /* cap seq at largest itx seq */ for (;;) { if (zilog->zl_ss_seq >= seq) { /* already on stable storage */ mutex_exit(&zilog->zl_lock); return; } if (zilog->zl_writer == B_FALSE) /* no one writing, do it */ break; cv_wait(&zilog->zl_cv_write, &zilog->zl_lock); } zilog->zl_writer = B_TRUE; max_seq = 0; if (zilog->zl_suspend) { lwb = NULL; } else { lwb = list_tail(&zilog->zl_lwb_list); if (lwb == NULL) { mutex_exit(&zilog->zl_lock); zil_create(zilog); mutex_enter(&zilog->zl_lock); lwb = list_tail(&zilog->zl_lwb_list); } } /* * Loop through in-memory log transactions filling log blocks, * until we reach the given sequence number and there's no more * room in the write buffer. */ for (;;) { itx = list_head(&zilog->zl_itx_list); if (itx == NULL) break; reclen = itx->itx_lr.lrc_reclen; if ((itx->itx_lr.lrc_seq > seq) && ((lwb == NULL) || (lwb->lwb_nused + reclen > ZIL_BLK_DATA_SZ(lwb)))) break; list_remove(&zilog->zl_itx_list, itx); txg = itx->itx_lr.lrc_txg; ASSERT(txg); mutex_exit(&zilog->zl_lock); if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) lwb = zil_lwb_commit(zilog, itx, lwb); else max_seq = itx->itx_lr.lrc_seq; kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); mutex_enter(&zilog->zl_lock); zilog->zl_itx_list_sz -= reclen; } mutex_exit(&zilog->zl_lock); /* write the last block out */ if (lwb != NULL && lwb->lwb_nused != 0) lwb = zil_lwb_write_start(zilog, lwb); zilog->zl_prev_used = zilog->zl_cur_used; zilog->zl_cur_used = 0; mutex_enter(&zilog->zl_lock); if (max_seq > zilog->zl_ss_seq) { zilog->zl_ss_seq = max_seq; cv_broadcast(&zilog->zl_cv_seq); } /* * Wait if necessary for our seq to be committed. */ if (lwb) { while (zilog->zl_ss_seq < seq && zilog->zl_log_error == 0) cv_wait(&zilog->zl_cv_seq, &zilog->zl_lock); zil_flush_vdevs(zilog, seq); } if (zilog->zl_log_error || lwb == NULL) { zilog->zl_log_error = 0; max_seq = zilog->zl_itx_seq; mutex_exit(&zilog->zl_lock); txg_wait_synced(zilog->zl_dmu_pool, 0); mutex_enter(&zilog->zl_lock); zilog->zl_ss_seq = MAX(max_seq, zilog->zl_ss_seq); cv_broadcast(&zilog->zl_cv_seq); } /* wake up others waiting to start a write */ zilog->zl_writer = B_FALSE; mutex_exit(&zilog->zl_lock); cv_broadcast(&zilog->zl_cv_write); } /* * Called in syncing context to free committed log blocks and update log header. */ void zil_sync(zilog_t *zilog, dmu_tx_t *tx) { uint64_t txg = dmu_tx_get_txg(tx); spa_t *spa = zilog->zl_spa; lwb_t *lwb; ASSERT(zilog->zl_stop_sync == 0); zilog->zl_header->zh_replay_seq = zilog->zl_replay_seq[txg & TXG_MASK]; if (zilog->zl_destroy_txg == txg) { bzero(zilog->zl_header, sizeof (zil_header_t)); bzero(zilog->zl_replay_seq, sizeof (zilog->zl_replay_seq)); zilog->zl_destroy_txg = 0; } mutex_enter(&zilog->zl_lock); for (;;) { lwb = list_head(&zilog->zl_lwb_list); if (lwb == NULL) { mutex_exit(&zilog->zl_lock); return; } if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) break; list_remove(&zilog->zl_lwb_list, lwb); zio_free_blk(spa, &lwb->lwb_blk, txg); kmem_cache_free(zil_lwb_cache, lwb); } zilog->zl_header->zh_log = lwb->lwb_blk; mutex_exit(&zilog->zl_lock); } void zil_init(void) { zil_lwb_cache = kmem_cache_create("zil_lwb_cache", sizeof (struct lwb), NULL, NULL, NULL, NULL, NULL, NULL, 0); } void zil_fini(void) { kmem_cache_destroy(zil_lwb_cache); } zilog_t * zil_alloc(objset_t *os, zil_header_t *zh_phys) { zilog_t *zilog; zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); zilog->zl_header = zh_phys; zilog->zl_os = os; zilog->zl_spa = dmu_objset_spa(os); zilog->zl_dmu_pool = dmu_objset_pool(os); list_create(&zilog->zl_itx_list, sizeof (itx_t), offsetof(itx_t, itx_node)); list_create(&zilog->zl_lwb_list, sizeof (lwb_t), offsetof(lwb_t, lwb_node)); list_create(&zilog->zl_vdev_list, sizeof (zil_vdev_t), offsetof(zil_vdev_t, vdev_seq_node)); return (zilog); } void zil_free(zilog_t *zilog) { lwb_t *lwb; zil_vdev_t *zv; zilog->zl_stop_sync = 1; while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { list_remove(&zilog->zl_lwb_list, lwb); if (lwb->lwb_buf != NULL) zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); kmem_cache_free(zil_lwb_cache, lwb); } list_destroy(&zilog->zl_lwb_list); while ((zv = list_head(&zilog->zl_vdev_list)) != NULL) { list_remove(&zilog->zl_vdev_list, zv); kmem_free(zv, sizeof (zil_vdev_t)); } list_destroy(&zilog->zl_vdev_list); ASSERT(list_head(&zilog->zl_itx_list) == NULL); list_destroy(&zilog->zl_itx_list); kmem_free(zilog, sizeof (zilog_t)); } /* * return true if the initial log block is not valid */ static int zil_empty(zilog_t *zilog) { blkptr_t blk; char *lrbuf; int error; blk = zilog->zl_header->zh_log; if (BP_IS_HOLE(&blk)) return (1); lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); error = zil_read_log_block(zilog, &blk, lrbuf); zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); return (error ? 1 : 0); } /* * Open an intent log. */ zilog_t * zil_open(objset_t *os, zil_get_data_t *get_data) { zilog_t *zilog = dmu_objset_zil(os); zilog->zl_get_data = get_data; zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 2, 2, TASKQ_PREPOPULATE); return (zilog); } /* * Close an intent log. */ void zil_close(zilog_t *zilog) { if (!zil_is_committed(zilog)) txg_wait_synced(zilog->zl_dmu_pool, 0); taskq_destroy(zilog->zl_clean_taskq); zilog->zl_clean_taskq = NULL; zilog->zl_get_data = NULL; zil_itx_clean(zilog); ASSERT(list_head(&zilog->zl_itx_list) == NULL); } /* * Suspend an intent log. While in suspended mode, we still honor * synchronous semantics, but we rely on txg_wait_synced() to do it. * We suspend the log briefly when taking a snapshot so that the snapshot * contains all the data it's supposed to, and has an empty intent log. */ int zil_suspend(zilog_t *zilog) { lwb_t *lwb; mutex_enter(&zilog->zl_lock); if (zilog->zl_header->zh_claim_txg != 0) { /* unplayed log */ mutex_exit(&zilog->zl_lock); return (EBUSY); } zilog->zl_suspend++; mutex_exit(&zilog->zl_lock); zil_commit(zilog, UINT64_MAX, FSYNC); mutex_enter(&zilog->zl_lock); while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { if (lwb->lwb_buf != NULL) { /* * Wait for the buffer if it's in the process of * being written. */ if ((lwb->lwb_seq != 0) && (lwb->lwb_state != SEQ_COMPLETE)) { cv_wait(&zilog->zl_cv_seq, &zilog->zl_lock); continue; } zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); } list_remove(&zilog->zl_lwb_list, lwb); kmem_cache_free(zil_lwb_cache, lwb); } mutex_exit(&zilog->zl_lock); zil_destroy(zilog); return (0); } void zil_resume(zilog_t *zilog) { mutex_enter(&zilog->zl_lock); ASSERT(zilog->zl_suspend != 0); zilog->zl_suspend--; mutex_exit(&zilog->zl_lock); } typedef struct zil_replay_arg { objset_t *zr_os; zil_replay_func_t **zr_replay; void *zr_arg; void (*zr_rm_sync)(void *arg); uint64_t *zr_txgp; boolean_t zr_byteswap; char *zr_lrbuf; } zil_replay_arg_t; static void zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) { zil_replay_arg_t *zr = zra; zil_header_t *zh = zilog->zl_header; uint64_t reclen = lr->lrc_reclen; uint64_t txtype = lr->lrc_txtype; int pass, error; if (zilog->zl_stop_replay) return; if (lr->lrc_txg < claim_txg) /* already committed */ return; if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ return; /* * Make a copy of the data so we can revise and extend it. */ bcopy(lr, zr->zr_lrbuf, reclen); /* * The log block containing this lr may have been byteswapped * so that we can easily examine common fields like lrc_txtype. * However, the log is a mix of different data types, and only the * replay vectors know how to byteswap their records. Therefore, if * the lr was byteswapped, undo it before invoking the replay vector. */ if (zr->zr_byteswap) byteswap_uint64_array(zr->zr_lrbuf, reclen); /* * If this is a TX_WRITE with a blkptr, suck in the data. */ if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { lr_write_t *lrw = (lr_write_t *)lr; blkptr_t *wbp = &lrw->lr_blkptr; uint64_t wlen = lrw->lr_length; char *wbuf = zr->zr_lrbuf + reclen; if (BP_IS_HOLE(wbp)) { /* compressed to a hole */ bzero(wbuf, wlen); } else { /* * A subsequent write may have overwritten this block, * in which case wbp may have been been freed and * reallocated, and our read of wbp may fail with a * checksum error. We can safely ignore this because * the later write will provide the correct data. */ zbookmark_t zb; zb.zb_objset = dmu_objset_id(zilog->zl_os); zb.zb_object = lrw->lr_foid; zb.zb_level = -1; zb.zb_blkid = lrw->lr_offset / BP_GET_LSIZE(wbp); (void) zio_wait(zio_read(NULL, zilog->zl_spa, wbp, wbuf, BP_GET_LSIZE(wbp), NULL, NULL, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb)); (void) memmove(wbuf, wbuf + lrw->lr_blkoff, wlen); } } /* * We must now do two things atomically: replay this log record, * and update the log header to reflect the fact that we did so. * We use the DMU's ability to assign into a specific txg to do this. */ for (pass = 1; /* CONSTANTCONDITION */; pass++) { uint64_t replay_txg; dmu_tx_t *replay_tx; replay_tx = dmu_tx_create(zr->zr_os); error = dmu_tx_assign(replay_tx, TXG_WAIT); if (error) { dmu_tx_abort(replay_tx); break; } replay_txg = dmu_tx_get_txg(replay_tx); if (txtype == 0 || txtype >= TX_MAX_TYPE) { error = EINVAL; } else { /* * On the first pass, arrange for the replay vector * to fail its dmu_tx_assign(). That's the only way * to ensure that those code paths remain well tested. */ *zr->zr_txgp = replay_txg - (pass == 1); error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lrbuf, zr->zr_byteswap); *zr->zr_txgp = TXG_NOWAIT; } if (error == 0) { dsl_dataset_dirty(dmu_objset_ds(zr->zr_os), replay_tx); zilog->zl_replay_seq[replay_txg & TXG_MASK] = lr->lrc_seq; } dmu_tx_commit(replay_tx); if (error != ERESTART) break; if (pass != 1) txg_wait_open(spa_get_dsl(zilog->zl_spa), replay_txg + 1); dprintf("pass %d, retrying\n", pass); } if (error) { char *name = kmem_alloc(MAXNAMELEN, KM_SLEEP); dmu_objset_name(zr->zr_os, name); cmn_err(CE_WARN, "ZFS replay transaction error %d, " "dataset %s, seq 0x%llx, txtype %llu\n", error, name, (u_longlong_t)lr->lrc_seq, (u_longlong_t)txtype); zilog->zl_stop_replay = 1; kmem_free(name, MAXNAMELEN); } /* * The DMU's dnode layer doesn't see removes until the txg commits, * so a subsequent claim can spuriously fail with EEXIST. * To prevent this, if we might have removed an object, * wait for the delete thread to delete it, and then * wait for the transaction group to sync. */ if (txtype == TX_REMOVE || txtype == TX_RMDIR || txtype == TX_RENAME) { if (zr->zr_rm_sync != NULL) zr->zr_rm_sync(zr->zr_arg); txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); } } /* * If this dataset has a non-empty intent log, replay it and destroy it. */ void zil_replay(objset_t *os, void *arg, uint64_t *txgp, zil_replay_func_t *replay_func[TX_MAX_TYPE], void (*rm_sync)(void *arg)) { zilog_t *zilog = dmu_objset_zil(os); zil_replay_arg_t zr; if (zil_empty(zilog)) { /* * Initialise the log header but don't free the log block * which will get reused. */ zilog->zl_header->zh_claim_txg = 0; zilog->zl_header->zh_replay_seq = 0; return; } zr.zr_os = os; zr.zr_replay = replay_func; zr.zr_arg = arg; zr.zr_rm_sync = rm_sync; zr.zr_txgp = txgp; zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zilog->zl_header->zh_log); zr.zr_lrbuf = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); /* * Wait for in-progress removes to sync before starting replay. */ if (rm_sync != NULL) rm_sync(arg); txg_wait_synced(zilog->zl_dmu_pool, 0); zilog->zl_stop_replay = 0; zil_parse(zilog, NULL, zil_replay_log_record, &zr, zilog->zl_header->zh_claim_txg); kmem_free(zr.zr_lrbuf, 2 * SPA_MAXBLOCKSIZE); zil_destroy(zilog); } /* * Report whether all transactions are committed */ int zil_is_committed(zilog_t *zilog) { lwb_t *lwb; if (zilog == NULL || list_head(&zilog->zl_itx_list)) return (B_FALSE); /* * A log write buffer at the head of the list that is not UNWRITTEN * means there's a lwb yet to be freed after a txg commit */ lwb = list_head(&zilog->zl_lwb_list); if (lwb && lwb->lwb_state != UNWRITTEN) return (B_FALSE); ASSERT(zil_empty(zilog)); return (B_TRUE); }