/* * 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) 2017, 2018 by Delphix. All rights reserved. */ #include #include #include #include #include #include #include #include #ifdef _KERNEL #include #include #include #endif /* * This controls the number of entries in the buffer the redaction_list_update * synctask uses to buffer writes to the redaction list. */ int redact_sync_bufsize = 1024; /* * Controls how often to update the redaction list when creating a redaction * list. */ uint64_t redaction_list_update_interval_ns = 1000 * 1000 * 1000ULL; /* NS */ /* * This tunable controls the length of the queues that zfs redact worker threads * use to communicate. If the dmu_redact_snap thread is blocking on these * queues, this variable may need to be increased. If there is a significant * slowdown at the start of a redact operation as these threads consume all the * available IO resources, or the queues are consuming too much memory, this * variable may need to be decreased. */ int zfs_redact_queue_length = 1024 * 1024; /* * These tunables control the fill fraction of the queues by zfs redact. The * fill fraction controls the frequency with which threads have to be * cv_signaled. If a lot of cpu time is being spent on cv_signal, then these * should be tuned down. If the queues empty before the signalled thread can * catch up, then these should be tuned up. */ uint64_t zfs_redact_queue_ff = 20; struct redact_record { bqueue_node_t ln; boolean_t eos_marker; /* Marks the end of the stream */ uint64_t start_object; uint64_t start_blkid; uint64_t end_object; uint64_t end_blkid; uint8_t indblkshift; uint32_t datablksz; }; struct redact_thread_arg { bqueue_t q; objset_t *os; /* Objset to traverse */ dsl_dataset_t *ds; /* Dataset to traverse */ struct redact_record *current_record; int error_code; boolean_t cancel; zbookmark_phys_t resume; objlist_t *deleted_objs; uint64_t *num_blocks_visited; uint64_t ignore_object; /* ignore further callbacks on this */ uint64_t txg; /* txg to traverse since */ }; /* * The redaction node is a wrapper around the redaction record that is used * by the redaction merging thread to sort the records and determine overlaps. * * It contains two nodes; one sorts the records by their start_zb, and the other * sorts the records by their end_zb. */ struct redact_node { avl_node_t avl_node_start; avl_node_t avl_node_end; struct redact_record *record; struct redact_thread_arg *rt_arg; uint32_t thread_num; }; struct merge_data { list_t md_redact_block_pending; redact_block_phys_t md_coalesce_block; uint64_t md_last_time; redact_block_phys_t md_furthest[TXG_SIZE]; /* Lists of struct redact_block_list_node. */ list_t md_blocks[TXG_SIZE]; boolean_t md_synctask_txg[TXG_SIZE]; uint64_t md_latest_synctask_txg; redaction_list_t *md_redaction_list; }; /* * A wrapper around struct redact_block so it can be stored in a list_t. */ struct redact_block_list_node { redact_block_phys_t block; list_node_t node; }; /* * We've found a new redaction candidate. In order to improve performance, we * coalesce these blocks when they're adjacent to each other. This function * handles that. If the new candidate block range is immediately after the * range we're building, coalesce it into the range we're building. Otherwise, * put the record we're building on the queue, and update the build pointer to * point to the new record. */ static void record_merge_enqueue(bqueue_t *q, struct redact_record **build, struct redact_record *new) { if (new->eos_marker) { if (*build != NULL) bqueue_enqueue(q, *build, sizeof (*build)); bqueue_enqueue_flush(q, new, sizeof (*new)); return; } if (*build == NULL) { *build = new; return; } struct redact_record *curbuild = *build; if ((curbuild->end_object == new->start_object && curbuild->end_blkid + 1 == new->start_blkid && curbuild->end_blkid != UINT64_MAX) || (curbuild->end_object + 1 == new->start_object && curbuild->end_blkid == UINT64_MAX && new->start_blkid == 0)) { curbuild->end_object = new->end_object; curbuild->end_blkid = new->end_blkid; kmem_free(new, sizeof (*new)); } else { bqueue_enqueue(q, curbuild, sizeof (*curbuild)); *build = new; } } #ifdef _KERNEL struct objnode { avl_node_t node; uint64_t obj; }; static int objnode_compare(const void *o1, const void *o2) { const struct objnode *obj1 = o1; const struct objnode *obj2 = o2; if (obj1->obj < obj2->obj) return (-1); if (obj1->obj > obj2->obj) return (1); return (0); } static objlist_t * zfs_get_deleteq(objset_t *os) { objlist_t *deleteq_objlist = objlist_create(); uint64_t deleteq_obj; zap_cursor_t zc; zap_attribute_t za; dmu_object_info_t doi; ASSERT3U(os->os_phys->os_type, ==, DMU_OST_ZFS); VERIFY0(dmu_object_info(os, MASTER_NODE_OBJ, &doi)); ASSERT3U(doi.doi_type, ==, DMU_OT_MASTER_NODE); VERIFY0(zap_lookup(os, MASTER_NODE_OBJ, ZFS_UNLINKED_SET, sizeof (uint64_t), 1, &deleteq_obj)); /* * In order to insert objects into the objlist, they must be in sorted * order. We don't know what order we'll get them out of the ZAP in, so * we insert them into and remove them from an avl_tree_t to sort them. */ avl_tree_t at; avl_create(&at, objnode_compare, sizeof (struct objnode), offsetof(struct objnode, node)); for (zap_cursor_init(&zc, os, deleteq_obj); zap_cursor_retrieve(&zc, &za) == 0; zap_cursor_advance(&zc)) { struct objnode *obj = kmem_zalloc(sizeof (*obj), KM_SLEEP); obj->obj = za.za_first_integer; avl_add(&at, obj); } zap_cursor_fini(&zc); struct objnode *next, *found = avl_first(&at); while (found != NULL) { next = AVL_NEXT(&at, found); objlist_insert(deleteq_objlist, found->obj); found = next; } void *cookie = NULL; while ((found = avl_destroy_nodes(&at, &cookie)) != NULL) kmem_free(found, sizeof (*found)); avl_destroy(&at); return (deleteq_objlist); } #endif /* * This is the callback function to traverse_dataset for the redaction threads * for dmu_redact_snap. This thread is responsible for creating redaction * records for all the data that is modified by the snapshots we're redacting * with respect to. Redaction records represent ranges of data that have been * modified by one of the redaction snapshots, and are stored in the * redact_record struct. We need to create redaction records for three * cases: * * First, if there's a normal write, we need to create a redaction record for * that block. * * Second, if there's a hole, we need to create a redaction record that covers * the whole range of the hole. If the hole is in the meta-dnode, it must cover * every block in all of the objects in the hole. * * Third, if there is a deleted object, we need to create a redaction record for * all of the blocks in that object. */ /*ARGSUSED*/ static int redact_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg) { struct redact_thread_arg *rta = arg; struct redact_record *record; ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT || zb->zb_object >= rta->resume.zb_object); if (rta->cancel) return (SET_ERROR(EINTR)); if (rta->ignore_object == zb->zb_object) return (0); /* * If we're visiting a dnode, we need to handle the case where the * object has been deleted. */ if (zb->zb_level == ZB_DNODE_LEVEL) { ASSERT3U(zb->zb_level, ==, ZB_DNODE_LEVEL); if (zb->zb_object == 0) return (0); /* * If the object has been deleted, redact all of the blocks in * it. */ if (dnp->dn_type == DMU_OT_NONE || objlist_exists(rta->deleted_objs, zb->zb_object)) { rta->ignore_object = zb->zb_object; record = kmem_zalloc(sizeof (struct redact_record), KM_SLEEP); record->eos_marker = B_FALSE; record->start_object = record->end_object = zb->zb_object; record->start_blkid = 0; record->end_blkid = UINT64_MAX; record_merge_enqueue(&rta->q, &rta->current_record, record); } return (0); } else if (zb->zb_level < 0) { return (0); } else if (zb->zb_level > 0 && !BP_IS_HOLE(bp)) { /* * If this is an indirect block, but not a hole, it doesn't * provide any useful information for redaction, so ignore it. */ return (0); } /* * At this point, there are two options left for the type of block we're * looking at. Either this is a hole (which could be in the dnode or * the meta-dnode), or it's a level 0 block of some sort. If it's a * hole, we create a redaction record that covers the whole range. If * the hole is in a dnode, we need to redact all the blocks in that * hole. If the hole is in the meta-dnode, we instead need to redact * all blocks in every object covered by that hole. If it's a level 0 * block, we only need to redact that single block. */ record = kmem_zalloc(sizeof (struct redact_record), KM_SLEEP); record->eos_marker = B_FALSE; record->start_object = record->end_object = zb->zb_object; if (BP_IS_HOLE(bp)) { record->start_blkid = zb->zb_blkid * bp_span_in_blocks(dnp->dn_indblkshift, zb->zb_level); record->end_blkid = ((zb->zb_blkid + 1) * bp_span_in_blocks(dnp->dn_indblkshift, zb->zb_level)) - 1; if (zb->zb_object == DMU_META_DNODE_OBJECT) { record->start_object = record->start_blkid * ((SPA_MINBLOCKSIZE * dnp->dn_datablkszsec) / sizeof (dnode_phys_t)); record->start_blkid = 0; record->end_object = ((record->end_blkid + 1) * ((SPA_MINBLOCKSIZE * dnp->dn_datablkszsec) / sizeof (dnode_phys_t))) - 1; record->end_blkid = UINT64_MAX; } } else if (zb->zb_level != 0 || zb->zb_object == DMU_META_DNODE_OBJECT) { kmem_free(record, sizeof (*record)); return (0); } else { record->start_blkid = record->end_blkid = zb->zb_blkid; } record->indblkshift = dnp->dn_indblkshift; record->datablksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT; record_merge_enqueue(&rta->q, &rta->current_record, record); return (0); } static void redact_traverse_thread(void *arg) { struct redact_thread_arg *rt_arg = arg; int err; struct redact_record *data; #ifdef _KERNEL if (rt_arg->os->os_phys->os_type == DMU_OST_ZFS) rt_arg->deleted_objs = zfs_get_deleteq(rt_arg->os); else rt_arg->deleted_objs = objlist_create(); #else rt_arg->deleted_objs = objlist_create(); #endif err = traverse_dataset_resume(rt_arg->ds, rt_arg->txg, &rt_arg->resume, TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, redact_cb, rt_arg); if (err != EINTR) rt_arg->error_code = err; objlist_destroy(rt_arg->deleted_objs); data = kmem_zalloc(sizeof (*data), KM_SLEEP); data->eos_marker = B_TRUE; record_merge_enqueue(&rt_arg->q, &rt_arg->current_record, data); thread_exit(); } static inline void create_zbookmark_from_obj_off(zbookmark_phys_t *zb, uint64_t object, uint64_t blkid) { zb->zb_object = object; zb->zb_level = 0; zb->zb_blkid = blkid; } /* * This is a utility function that can do the comparison for the start or ends * of the ranges in a redact_record. */ static int redact_range_compare(uint64_t obj1, uint64_t off1, uint32_t dbss1, uint64_t obj2, uint64_t off2, uint32_t dbss2) { zbookmark_phys_t z1, z2; create_zbookmark_from_obj_off(&z1, obj1, off1); create_zbookmark_from_obj_off(&z2, obj2, off2); return (zbookmark_compare(dbss1 >> SPA_MINBLOCKSHIFT, 0, dbss2 >> SPA_MINBLOCKSHIFT, 0, &z1, &z2)); } /* * Compare two redaction records by their range's start location. Also makes * eos records always compare last. We use the thread number in the redact_node * to ensure that records do not compare equal (which is not allowed in our avl * trees). */ static int redact_node_compare_start(const void *arg1, const void *arg2) { const struct redact_node *rn1 = arg1; const struct redact_node *rn2 = arg2; const struct redact_record *rr1 = rn1->record; const struct redact_record *rr2 = rn2->record; if (rr1->eos_marker) return (1); if (rr2->eos_marker) return (-1); int cmp = redact_range_compare(rr1->start_object, rr1->start_blkid, rr1->datablksz, rr2->start_object, rr2->start_blkid, rr2->datablksz); if (cmp == 0) cmp = (rn1->thread_num < rn2->thread_num ? -1 : 1); return (cmp); } /* * Compare two redaction records by their range's end location. Also makes * eos records always compare last. We use the thread number in the redact_node * to ensure that records do not compare equal (which is not allowed in our avl * trees). */ static int redact_node_compare_end(const void *arg1, const void *arg2) { const struct redact_node *rn1 = arg1; const struct redact_node *rn2 = arg2; const struct redact_record *srr1 = rn1->record; const struct redact_record *srr2 = rn2->record; if (srr1->eos_marker) return (1); if (srr2->eos_marker) return (-1); int cmp = redact_range_compare(srr1->end_object, srr1->end_blkid, srr1->datablksz, srr2->end_object, srr2->end_blkid, srr2->datablksz); if (cmp == 0) cmp = (rn1->thread_num < rn2->thread_num ? -1 : 1); return (cmp); } /* * Utility function that compares two redaction records to determine if any part * of the "from" record is before any part of the "to" record. Also causes End * of Stream redaction records to compare after all others, so that the * redaction merging logic can stay simple. */ static boolean_t redact_record_before(const struct redact_record *from, const struct redact_record *to) { if (from->eos_marker == B_TRUE) return (B_FALSE); else if (to->eos_marker == B_TRUE) return (B_TRUE); return (redact_range_compare(from->start_object, from->start_blkid, from->datablksz, to->end_object, to->end_blkid, to->datablksz) <= 0); } /* * Pop a new redaction record off the queue, check that the records are in the * right order, and free the old data. */ static struct redact_record * get_next_redact_record(bqueue_t *bq, struct redact_record *prev) { struct redact_record *next = bqueue_dequeue(bq); ASSERT(redact_record_before(prev, next)); kmem_free(prev, sizeof (*prev)); return (next); } /* * Remove the given redaction node from both trees, pull a new redaction record * off the queue, free the old redaction record, update the redaction node, and * reinsert the node into the trees. */ static int update_avl_trees(avl_tree_t *start_tree, avl_tree_t *end_tree, struct redact_node *redact_node) { avl_remove(start_tree, redact_node); avl_remove(end_tree, redact_node); redact_node->record = get_next_redact_record(&redact_node->rt_arg->q, redact_node->record); avl_add(end_tree, redact_node); avl_add(start_tree, redact_node); return (redact_node->rt_arg->error_code); } /* * Synctask for updating redaction lists. We first take this txg's list of * redacted blocks and append those to the redaction list. We then update the * redaction list's bonus buffer. We store the furthest blocks we visited and * the list of snapshots that we're redacting with respect to. We need these so * that redacted sends and receives can be correctly resumed. */ static void redaction_list_update_sync(void *arg, dmu_tx_t *tx) { struct merge_data *md = arg; uint64_t txg = dmu_tx_get_txg(tx); list_t *list = &md->md_blocks[txg & TXG_MASK]; redact_block_phys_t *furthest_visited = &md->md_furthest[txg & TXG_MASK]; objset_t *mos = tx->tx_pool->dp_meta_objset; redaction_list_t *rl = md->md_redaction_list; int bufsize = redact_sync_bufsize; redact_block_phys_t *buf = kmem_alloc(bufsize * sizeof (*buf), KM_SLEEP); int index = 0; dmu_buf_will_dirty(rl->rl_dbuf, tx); for (struct redact_block_list_node *rbln = list_remove_head(list); rbln != NULL; rbln = list_remove_head(list)) { ASSERT3U(rbln->block.rbp_object, <=, furthest_visited->rbp_object); ASSERT(rbln->block.rbp_object < furthest_visited->rbp_object || rbln->block.rbp_blkid <= furthest_visited->rbp_blkid); buf[index] = rbln->block; index++; if (index == bufsize) { dmu_write(mos, rl->rl_object, rl->rl_phys->rlp_num_entries * sizeof (*buf), bufsize * sizeof (*buf), buf, tx); rl->rl_phys->rlp_num_entries += bufsize; index = 0; } kmem_free(rbln, sizeof (*rbln)); } if (index > 0) { dmu_write(mos, rl->rl_object, rl->rl_phys->rlp_num_entries * sizeof (*buf), index * sizeof (*buf), buf, tx); rl->rl_phys->rlp_num_entries += index; } kmem_free(buf, bufsize * sizeof (*buf)); md->md_synctask_txg[txg & TXG_MASK] = B_FALSE; rl->rl_phys->rlp_last_object = furthest_visited->rbp_object; rl->rl_phys->rlp_last_blkid = furthest_visited->rbp_blkid; } static void commit_rl_updates(objset_t *os, struct merge_data *md, uint64_t object, uint64_t blkid) { dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(os->os_spa)->dp_mos_dir); dmu_tx_hold_space(tx, sizeof (struct redact_block_list_node)); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); uint64_t txg = dmu_tx_get_txg(tx); if (!md->md_synctask_txg[txg & TXG_MASK]) { dsl_sync_task_nowait(dmu_tx_pool(tx), redaction_list_update_sync, md, tx); md->md_synctask_txg[txg & TXG_MASK] = B_TRUE; md->md_latest_synctask_txg = txg; } md->md_furthest[txg & TXG_MASK].rbp_object = object; md->md_furthest[txg & TXG_MASK].rbp_blkid = blkid; list_move_tail(&md->md_blocks[txg & TXG_MASK], &md->md_redact_block_pending); dmu_tx_commit(tx); md->md_last_time = gethrtime(); } /* * We want to store the list of blocks that we're redacting in the bookmark's * redaction list. However, this list is stored in the MOS, which means it can * only be written to in syncing context. To get around this, we create a * synctask that will write to the mos for us. We tell it what to write by * a linked list for each current transaction group; every time we decide to * redact a block, we append it to the transaction group that is currently in * open context. We also update some progress information that the synctask * will store to enable resumable redacted sends. */ static void update_redaction_list(struct merge_data *md, objset_t *os, uint64_t object, uint64_t blkid, uint64_t endblkid, uint32_t blksz) { boolean_t enqueue = B_FALSE; redact_block_phys_t cur = {0}; uint64_t count = endblkid - blkid + 1; while (count > REDACT_BLOCK_MAX_COUNT) { update_redaction_list(md, os, object, blkid, blkid + REDACT_BLOCK_MAX_COUNT - 1, blksz); blkid += REDACT_BLOCK_MAX_COUNT; count -= REDACT_BLOCK_MAX_COUNT; } redact_block_phys_t *coalesce = &md->md_coalesce_block; boolean_t new; if (coalesce->rbp_size_count == 0) { new = B_TRUE; enqueue = B_FALSE; } else { uint64_t old_count = redact_block_get_count(coalesce); if (coalesce->rbp_object == object && coalesce->rbp_blkid + old_count == blkid && old_count + count <= REDACT_BLOCK_MAX_COUNT) { ASSERT3U(redact_block_get_size(coalesce), ==, blksz); redact_block_set_count(coalesce, old_count + count); new = B_FALSE; enqueue = B_FALSE; } else { new = B_TRUE; enqueue = B_TRUE; } } if (new) { cur = *coalesce; coalesce->rbp_blkid = blkid; coalesce->rbp_object = object; redact_block_set_count(coalesce, count); redact_block_set_size(coalesce, blksz); } if (enqueue && redact_block_get_size(&cur) != 0) { struct redact_block_list_node *rbln = kmem_alloc(sizeof (struct redact_block_list_node), KM_SLEEP); rbln->block = cur; list_insert_tail(&md->md_redact_block_pending, rbln); } if (gethrtime() > md->md_last_time + redaction_list_update_interval_ns) { commit_rl_updates(os, md, object, blkid); } } /* * This thread merges all the redaction records provided by the worker threads, * and determines which blocks are redacted by all the snapshots. The algorithm * for doing so is similar to performing a merge in mergesort with n sub-lists * instead of 2, with some added complexity due to the fact that the entries are * ranges, not just single blocks. This algorithm relies on the fact that the * queues are sorted, which is ensured by the fact that traverse_dataset * traverses the dataset in a consistent order. We pull one entry off the front * of the queues of each secure dataset traversal thread. Then we repeat the * following: each record represents a range of blocks modified by one of the * redaction snapshots, and each block in that range may need to be redacted in * the send stream. Find the record with the latest start of its range, and the * record with the earliest end of its range. If the last start is before the * first end, then we know that the blocks in the range [last_start, first_end] * are covered by all of the ranges at the front of the queues, which means * every thread redacts that whole range. For example, let's say the ranges on * each queue look like this: * * Block Id 1 2 3 4 5 6 7 8 9 10 11 * Thread 1 | [====================] * Thread 2 | [========] * Thread 3 | [=================] * * Thread 3 has the last start (5), and the thread 2 has the last end (6). All * three threads modified the range [5,6], so that data should not be sent over * the wire. After we've determined whether or not to redact anything, we take * the record with the first end. We discard that record, and pull a new one * off the front of the queue it came from. In the above example, we would * discard Thread 2's record, and pull a new one. Let's say the next record we * pulled from Thread 2 covered range [10,11]. The new layout would look like * this: * * Block Id 1 2 3 4 5 6 7 8 9 10 11 * Thread 1 | [====================] * Thread 2 | [==] * Thread 3 | [=================] * * When we compare the last start (10, from Thread 2) and the first end (9, from * Thread 1), we see that the last start is greater than the first end. * Therefore, we do not redact anything from these records. We'll iterate by * replacing the record from Thread 1. * * We iterate by replacing the record with the lowest end because we know * that the record with the lowest end has helped us as much as it can. All the * ranges before it that we will ever redact have been redacted. In addition, * by replacing the one with the lowest end, we guarantee we catch all ranges * that need to be redacted. For example, if in the case above we had replaced * the record from Thread 1 instead, we might have ended up with the following: * * Block Id 1 2 3 4 5 6 7 8 9 10 11 12 * Thread 1 | [==] * Thread 2 | [========] * Thread 3 | [=================] * * If the next record from Thread 2 had been [8,10], for example, we should have * redacted part of that range, but because we updated Thread 1's record, we * missed it. * * We implement this algorithm by using two trees. The first sorts the * redaction records by their start_zb, and the second sorts them by their * end_zb. We use these to find the record with the last start and the record * with the first end. We create a record with that start and end, and send it * on. The overall runtime of this implementation is O(n log m), where n is the * total number of redaction records from all the different redaction snapshots, * and m is the number of redaction snapshots. * * If we redact with respect to zero snapshots, we create a redaction * record with the start object and blkid to 0, and the end object and blkid to * UINT64_MAX. This will result in us redacting every block. */ static int perform_thread_merge(bqueue_t *q, uint32_t num_threads, struct redact_thread_arg *thread_args, boolean_t *cancel) { struct redact_node *redact_nodes = NULL; avl_tree_t start_tree, end_tree; struct redact_record *record; struct redact_record *current_record = NULL; int err = 0; struct merge_data md = { {0} }; list_create(&md.md_redact_block_pending, sizeof (struct redact_block_list_node), offsetof(struct redact_block_list_node, node)); /* * If we're redacting with respect to zero snapshots, then no data is * permitted to be sent. We enqueue a record that redacts all blocks, * and an eos marker. */ if (num_threads == 0) { record = kmem_zalloc(sizeof (struct redact_record), KM_SLEEP); // We can't redact object 0, so don't try. record->start_object = 1; record->start_blkid = 0; record->end_object = record->end_blkid = UINT64_MAX; bqueue_enqueue(q, record, sizeof (*record)); return (0); } if (num_threads > 0) { redact_nodes = kmem_zalloc(num_threads * sizeof (*redact_nodes), KM_SLEEP); } avl_create(&start_tree, redact_node_compare_start, sizeof (struct redact_node), offsetof(struct redact_node, avl_node_start)); avl_create(&end_tree, redact_node_compare_end, sizeof (struct redact_node), offsetof(struct redact_node, avl_node_end)); for (int i = 0; i < num_threads; i++) { struct redact_node *node = &redact_nodes[i]; struct redact_thread_arg *targ = &thread_args[i]; node->record = bqueue_dequeue(&targ->q); node->rt_arg = targ; node->thread_num = i; avl_add(&start_tree, node); avl_add(&end_tree, node); } /* * Once the first record in the end tree has returned EOS, every record * must be an EOS record, so we should stop. */ while (err == 0 && !((struct redact_node *)avl_first(&end_tree))-> record->eos_marker) { if (*cancel) { err = EINTR; break; } struct redact_node *last_start = avl_last(&start_tree); struct redact_node *first_end = avl_first(&end_tree); /* * If the last start record is before the first end record, * then we have blocks that are redacted by all threads. * Therefore, we should redact them. Copy the record, and send * it to the main thread. */ if (redact_record_before(last_start->record, first_end->record)) { record = kmem_zalloc(sizeof (struct redact_record), KM_SLEEP); *record = *first_end->record; record->start_object = last_start->record->start_object; record->start_blkid = last_start->record->start_blkid; record_merge_enqueue(q, ¤t_record, record); } err = update_avl_trees(&start_tree, &end_tree, first_end); } /* * We're done; if we were cancelled, we need to cancel our workers and * clear out their queues. Either way, we need to remove every thread's * redact_node struct from the avl trees. */ for (int i = 0; i < num_threads; i++) { if (err != 0) { thread_args[i].cancel = B_TRUE; while (!redact_nodes[i].record->eos_marker) { (void) update_avl_trees(&start_tree, &end_tree, &redact_nodes[i]); } } avl_remove(&start_tree, &redact_nodes[i]); avl_remove(&end_tree, &redact_nodes[i]); kmem_free(redact_nodes[i].record, sizeof (struct redact_record)); } avl_destroy(&start_tree); avl_destroy(&end_tree); kmem_free(redact_nodes, num_threads * sizeof (*redact_nodes)); if (current_record != NULL) bqueue_enqueue(q, current_record, sizeof (current_record)); return (err); } struct redact_merge_thread_arg { bqueue_t q; spa_t *spa; int numsnaps; struct redact_thread_arg *thr_args; boolean_t cancel; int error_code; }; static void redact_merge_thread(void *arg) { struct redact_merge_thread_arg *rmta = arg; rmta->error_code = perform_thread_merge(&rmta->q, rmta->numsnaps, rmta->thr_args, &rmta->cancel); struct redact_record *rec = kmem_zalloc(sizeof (*rec), KM_SLEEP); rec->eos_marker = B_TRUE; bqueue_enqueue_flush(&rmta->q, rec, 1); thread_exit(); } /* * Find the next object in or after the redaction range passed in, and hold * its dnode with the provided tag. Also update *object to contain the new * object number. */ static int hold_next_object(objset_t *os, struct redact_record *rec, void *tag, uint64_t *object, dnode_t **dn) { int err = 0; if (*dn != NULL) dnode_rele(*dn, FTAG); *dn = NULL; if (*object < rec->start_object) { *object = rec->start_object - 1; } err = dmu_object_next(os, object, B_FALSE, 0); if (err != 0) return (err); err = dnode_hold(os, *object, tag, dn); while (err == 0 && (*object < rec->start_object || DMU_OT_IS_METADATA((*dn)->dn_type))) { dnode_rele(*dn, tag); *dn = NULL; err = dmu_object_next(os, object, B_FALSE, 0); if (err != 0) break; err = dnode_hold(os, *object, tag, dn); } return (err); } static int perform_redaction(objset_t *os, redaction_list_t *rl, struct redact_merge_thread_arg *rmta) { int err = 0; bqueue_t *q = &rmta->q; struct redact_record *rec = NULL; struct merge_data md = { {0} }; list_create(&md.md_redact_block_pending, sizeof (struct redact_block_list_node), offsetof(struct redact_block_list_node, node)); md.md_redaction_list = rl; for (int i = 0; i < TXG_SIZE; i++) { list_create(&md.md_blocks[i], sizeof (struct redact_block_list_node), offsetof(struct redact_block_list_node, node)); } dnode_t *dn = NULL; uint64_t prev_obj = 0; for (rec = bqueue_dequeue(q); !rec->eos_marker && err == 0; rec = get_next_redact_record(q, rec)) { ASSERT3U(rec->start_object, !=, 0); uint64_t object; if (prev_obj != rec->start_object) { object = rec->start_object - 1; err = hold_next_object(os, rec, FTAG, &object, &dn); } else { object = prev_obj; } while (err == 0 && object <= rec->end_object) { if (issig(JUSTLOOKING) && issig(FORREAL)) { err = EINTR; break; } /* * Part of the current object is contained somewhere in * the range covered by rec. */ uint64_t startblkid; uint64_t endblkid; uint64_t maxblkid = dn->dn_phys->dn_maxblkid; if (rec->start_object < object) startblkid = 0; else if (rec->start_blkid > maxblkid) break; else startblkid = rec->start_blkid; if (rec->end_object > object || rec->end_blkid > maxblkid) { endblkid = maxblkid; } else { endblkid = rec->end_blkid; } update_redaction_list(&md, os, object, startblkid, endblkid, dn->dn_datablksz); if (object == rec->end_object) break; err = hold_next_object(os, rec, FTAG, &object, &dn); } if (err == ESRCH) err = 0; if (dn != NULL) prev_obj = object; } if (err == 0 && dn != NULL) dnode_rele(dn, FTAG); if (err == ESRCH) err = 0; rmta->cancel = B_TRUE; while (!rec->eos_marker) rec = get_next_redact_record(q, rec); kmem_free(rec, sizeof (*rec)); /* * There may be a block that's being coalesced, sync that out before we * return. */ if (err == 0 && md.md_coalesce_block.rbp_size_count != 0) { struct redact_block_list_node *rbln = kmem_alloc(sizeof (struct redact_block_list_node), KM_SLEEP); rbln->block = md.md_coalesce_block; list_insert_tail(&md.md_redact_block_pending, rbln); } commit_rl_updates(os, &md, UINT64_MAX, UINT64_MAX); /* * Wait for all the redaction info to sync out before we return, so that * anyone who attempts to resume this redaction will have all the data * they need. */ dsl_pool_t *dp = spa_get_dsl(os->os_spa); if (md.md_latest_synctask_txg != 0) txg_wait_synced(dp, md.md_latest_synctask_txg); for (int i = 0; i < TXG_SIZE; i++) list_destroy(&md.md_blocks[i]); return (err); } static boolean_t redact_snaps_contains(uint64_t *snaps, uint64_t num_snaps, uint64_t guid) { for (int i = 0; i < num_snaps; i++) { if (snaps[i] == guid) return (B_TRUE); } return (B_FALSE); } int dmu_redact_snap(const char *snapname, nvlist_t *redactnvl, const char *redactbook) { int err = 0; dsl_pool_t *dp = NULL; dsl_dataset_t *ds = NULL; int numsnaps = 0; objset_t *os; struct redact_thread_arg *args = NULL; redaction_list_t *new_rl = NULL; char *newredactbook; if ((err = dsl_pool_hold(snapname, FTAG, &dp)) != 0) return (err); newredactbook = kmem_zalloc(sizeof (char) * ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); if ((err = dsl_dataset_hold_flags(dp, snapname, DS_HOLD_FLAG_DECRYPT, FTAG, &ds)) != 0) { goto out; } dsl_dataset_long_hold(ds, FTAG); if (!ds->ds_is_snapshot || dmu_objset_from_ds(ds, &os) != 0) { err = EINVAL; goto out; } if (dsl_dataset_feature_is_active(ds, SPA_FEATURE_REDACTED_DATASETS)) { err = EALREADY; goto out; } numsnaps = fnvlist_num_pairs(redactnvl); if (numsnaps > 0) args = kmem_zalloc(numsnaps * sizeof (*args), KM_SLEEP); nvpair_t *pair = NULL; for (int i = 0; i < numsnaps; i++) { pair = nvlist_next_nvpair(redactnvl, pair); const char *name = nvpair_name(pair); struct redact_thread_arg *rta = &args[i]; err = dsl_dataset_hold_flags(dp, name, DS_HOLD_FLAG_DECRYPT, FTAG, &rta->ds); if (err != 0) break; /* * We want to do the long hold before we can get any other * errors, because the cleanup code will release the long * hold if rta->ds is filled in. */ dsl_dataset_long_hold(rta->ds, FTAG); err = dmu_objset_from_ds(rta->ds, &rta->os); if (err != 0) break; if (!dsl_dataset_is_before(rta->ds, ds, 0)) { err = EINVAL; break; } if (dsl_dataset_feature_is_active(rta->ds, SPA_FEATURE_REDACTED_DATASETS)) { err = EALREADY; break; } } VERIFY3P(nvlist_next_nvpair(redactnvl, pair), ==, NULL); if (err != 0) goto out; boolean_t resuming = B_FALSE; zfs_bookmark_phys_t bookmark; (void) strlcpy(newredactbook, snapname, ZFS_MAX_DATASET_NAME_LEN); char *c = strchr(newredactbook, '@'); ASSERT3P(c, !=, NULL); int n = snprintf(c, ZFS_MAX_DATASET_NAME_LEN - (c - newredactbook), "#%s", redactbook); if (n >= ZFS_MAX_DATASET_NAME_LEN - (c - newredactbook)) { dsl_pool_rele(dp, FTAG); kmem_free(newredactbook, sizeof (char) * ZFS_MAX_DATASET_NAME_LEN); return (SET_ERROR(ENAMETOOLONG)); } err = dsl_bookmark_lookup(dp, newredactbook, NULL, &bookmark); if (err == 0) { resuming = B_TRUE; if (bookmark.zbm_redaction_obj == 0) { err = EEXIST; goto out; } err = dsl_redaction_list_hold_obj(dp, bookmark.zbm_redaction_obj, FTAG, &new_rl); if (err != 0) { err = EIO; goto out; } dsl_redaction_list_long_hold(dp, new_rl, FTAG); if (new_rl->rl_phys->rlp_num_snaps != numsnaps) { err = ESRCH; goto out; } for (int i = 0; i < numsnaps; i++) { struct redact_thread_arg *rta = &args[i]; if (!redact_snaps_contains(new_rl->rl_phys->rlp_snaps, new_rl->rl_phys->rlp_num_snaps, dsl_dataset_phys(rta->ds)->ds_guid)) { err = ESRCH; goto out; } } if (new_rl->rl_phys->rlp_last_blkid == UINT64_MAX && new_rl->rl_phys->rlp_last_object == UINT64_MAX) { err = EEXIST; goto out; } dsl_pool_rele(dp, FTAG); dp = NULL; } else { uint64_t *guids = NULL; if (numsnaps > 0) { guids = kmem_zalloc(numsnaps * sizeof (uint64_t), KM_SLEEP); } for (int i = 0; i < numsnaps; i++) { struct redact_thread_arg *rta = &args[i]; guids[i] = dsl_dataset_phys(rta->ds)->ds_guid; } dsl_pool_rele(dp, FTAG); dp = NULL; err = dsl_bookmark_create_redacted(newredactbook, snapname, numsnaps, guids, FTAG, &new_rl); kmem_free(guids, numsnaps * sizeof (uint64_t)); if (err != 0) { goto out; } } for (int i = 0; i < numsnaps; i++) { struct redact_thread_arg *rta = &args[i]; (void) bqueue_init(&rta->q, zfs_redact_queue_ff, zfs_redact_queue_length, offsetof(struct redact_record, ln)); if (resuming) { rta->resume.zb_blkid = new_rl->rl_phys->rlp_last_blkid; rta->resume.zb_object = new_rl->rl_phys->rlp_last_object; } rta->txg = dsl_dataset_phys(ds)->ds_creation_txg; (void) thread_create(NULL, 0, redact_traverse_thread, rta, 0, curproc, TS_RUN, minclsyspri); } struct redact_merge_thread_arg *rmta; rmta = kmem_zalloc(sizeof (struct redact_merge_thread_arg), KM_SLEEP); (void) bqueue_init(&rmta->q, zfs_redact_queue_ff, zfs_redact_queue_length, offsetof(struct redact_record, ln)); rmta->numsnaps = numsnaps; rmta->spa = os->os_spa; rmta->thr_args = args; (void) thread_create(NULL, 0, redact_merge_thread, rmta, 0, curproc, TS_RUN, minclsyspri); err = perform_redaction(os, new_rl, rmta); kmem_free(rmta, sizeof (struct redact_merge_thread_arg)); out: kmem_free(newredactbook, sizeof (char) * ZFS_MAX_DATASET_NAME_LEN); if (new_rl != NULL) { dsl_redaction_list_long_rele(new_rl, FTAG); dsl_redaction_list_rele(new_rl, FTAG); } for (int i = 0; i < numsnaps; i++) { struct redact_thread_arg *rta = &args[i]; /* * rta->ds may be NULL if we got an error while filling * it in. */ if (rta->ds != NULL) { dsl_dataset_long_rele(rta->ds, FTAG); dsl_dataset_rele_flags(rta->ds, DS_HOLD_FLAG_DECRYPT, FTAG); } } if (args != NULL) kmem_free(args, numsnaps * sizeof (*args)); if (dp != NULL) dsl_pool_rele(dp, FTAG); if (ds != NULL) { dsl_dataset_long_rele(ds, FTAG); dsl_dataset_rele_flags(ds, DS_HOLD_FLAG_DECRYPT, FTAG); } return (SET_ERROR(err)); }