/* * 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. * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright (c) 2014 Integros [integros.com] */ /* Portions Copyright 2010 Robert Milkowski */ #ifndef _SYS_ZIL_IMPL_H #define _SYS_ZIL_IMPL_H #include <sys/zil.h> #include <sys/dmu_objset.h> #ifdef __cplusplus extern "C" { #endif /* * Possbile states for a given lwb structure. * * An lwb will start out in the "closed" state, and then transition to * the "opened" state via a call to zil_lwb_write_open(). When * transitioning from "closed" to "opened" the zilog's "zl_issuer_lock" * must be held. * * After the lwb is "opened", it can transition into the "issued" state * via zil_lwb_write_issue(). Again, the zilog's "zl_issuer_lock" must * be held when making this transition. * * After the lwb's write zio completes, it transitions into the "write * done" state via zil_lwb_write_done(); and then into the "flush done" * state via zil_lwb_flush_vdevs_done(). When transitioning from * "issued" to "write done", and then from "write done" to "flush done", * the zilog's "zl_lock" must be held, *not* the "zl_issuer_lock". * * The zilog's "zl_issuer_lock" can become heavily contended in certain * workloads, so we specifically avoid acquiring that lock when * transitioning an lwb from "issued" to "done". This allows us to avoid * having to acquire the "zl_issuer_lock" for each lwb ZIO completion, * which would have added more lock contention on an already heavily * contended lock. * * Additionally, correctness when reading an lwb's state is often * acheived by exploiting the fact that these state transitions occur in * this specific order; i.e. "closed" to "opened" to "issued" to "done". * * Thus, if an lwb is in the "closed" or "opened" state, holding the * "zl_issuer_lock" will prevent a concurrent thread from transitioning * that lwb to the "issued" state. Likewise, if an lwb is already in the * "issued" state, holding the "zl_lock" will prevent a concurrent * thread from transitioning that lwb to the "write done" state. */ typedef enum { LWB_STATE_CLOSED, LWB_STATE_OPENED, LWB_STATE_ISSUED, LWB_STATE_WRITE_DONE, LWB_STATE_FLUSH_DONE, LWB_NUM_STATES } lwb_state_t; /* * Log write block (lwb) * * Prior to an lwb being issued to disk via zil_lwb_write_issue(), it * will be protected by the zilog's "zl_issuer_lock". Basically, prior * to it being issued, it will only be accessed by the thread that's * holding the "zl_issuer_lock". After the lwb is issued, the zilog's * "zl_lock" is used to protect the lwb against concurrent access. */ typedef struct lwb { zilog_t *lwb_zilog; /* back pointer to log struct */ blkptr_t lwb_blk; /* on disk address of this log blk */ boolean_t lwb_slog; /* lwb_blk is on SLOG device */ int lwb_nused; /* # used bytes in buffer */ int lwb_sz; /* size of block and buffer */ lwb_state_t lwb_state; /* the state of this lwb */ char *lwb_buf; /* log write buffer */ zio_t *lwb_write_zio; /* zio for the lwb buffer */ zio_t *lwb_root_zio; /* root zio for lwb write and flushes */ dmu_tx_t *lwb_tx; /* tx for log block allocation */ uint64_t lwb_max_txg; /* highest txg in this lwb */ list_node_t lwb_node; /* zilog->zl_lwb_list linkage */ list_t lwb_waiters; /* list of zil_commit_waiter's */ avl_tree_t lwb_vdev_tree; /* vdevs to flush after lwb write */ kmutex_t lwb_vdev_lock; /* protects lwb_vdev_tree */ hrtime_t lwb_issued_timestamp; /* when was the lwb issued? */ } lwb_t; /* * ZIL commit waiter. * * This structure is allocated each time zil_commit() is called, and is * used by zil_commit() to communicate with other parts of the ZIL, such * that zil_commit() can know when it safe for it return. For more * details, see the comment above zil_commit(). * * The "zcw_lock" field is used to protect the commit waiter against * concurrent access. This lock is often acquired while already holding * the zilog's "zl_issuer_lock" or "zl_lock"; see the functions * zil_process_commit_list() and zil_lwb_flush_vdevs_done() as examples * of this. Thus, one must be careful not to acquire the * "zl_issuer_lock" or "zl_lock" when already holding the "zcw_lock"; * e.g. see the zil_commit_waiter_timeout() function. */ typedef struct zil_commit_waiter { kcondvar_t zcw_cv; /* signalled when "done" */ kmutex_t zcw_lock; /* protects fields of this struct */ list_node_t zcw_node; /* linkage in lwb_t:lwb_waiter list */ lwb_t *zcw_lwb; /* back pointer to lwb when linked */ boolean_t zcw_done; /* B_TRUE when "done", else B_FALSE */ int zcw_zio_error; /* contains the zio io_error value */ } zil_commit_waiter_t; /* * Intent log transaction lists */ typedef struct itxs { list_t i_sync_list; /* list of synchronous itxs */ avl_tree_t i_async_tree; /* tree of foids for async itxs */ } itxs_t; typedef struct itxg { kmutex_t itxg_lock; /* lock for this structure */ uint64_t itxg_txg; /* txg for this chain */ itxs_t *itxg_itxs; /* sync and async itxs */ } itxg_t; /* for async nodes we build up an AVL tree of lists of async itxs per file */ typedef struct itx_async_node { uint64_t ia_foid; /* file object id */ list_t ia_list; /* list of async itxs for this foid */ avl_node_t ia_node; /* AVL tree linkage */ } itx_async_node_t; /* * Vdev flushing: during a zil_commit(), we build up an AVL tree of the vdevs * we've touched so we know which ones need a write cache flush at the end. */ typedef struct zil_vdev_node { uint64_t zv_vdev; /* vdev to be flushed */ avl_node_t zv_node; /* AVL tree linkage */ } zil_vdev_node_t; #define ZIL_PREV_BLKS 16 /* * Stable storage intent log management structure. One per dataset. */ struct zilog { kmutex_t zl_lock; /* protects most zilog_t fields */ struct dsl_pool *zl_dmu_pool; /* DSL pool */ spa_t *zl_spa; /* handle for read/write log */ const zil_header_t *zl_header; /* log header buffer */ objset_t *zl_os; /* object set we're logging */ zil_get_data_t *zl_get_data; /* callback to get object content */ lwb_t *zl_last_lwb_opened; /* most recent lwb opened */ hrtime_t zl_last_lwb_latency; /* zio latency of last lwb done */ uint64_t zl_lr_seq; /* on-disk log record sequence number */ uint64_t zl_commit_lr_seq; /* last committed on-disk lr seq */ uint64_t zl_destroy_txg; /* txg of last zil_destroy() */ uint64_t zl_replayed_seq[TXG_SIZE]; /* last replayed rec seq */ uint64_t zl_replaying_seq; /* current replay seq number */ uint32_t zl_suspend; /* log suspend count */ kcondvar_t zl_cv_suspend; /* log suspend completion */ uint8_t zl_suspending; /* log is currently suspending */ uint8_t zl_keep_first; /* keep first log block in destroy */ uint8_t zl_replay; /* replaying records while set */ uint8_t zl_stop_sync; /* for debugging */ kmutex_t zl_issuer_lock; /* single writer, per ZIL, at a time */ uint8_t zl_logbias; /* latency or throughput */ uint8_t zl_sync; /* synchronous or asynchronous */ int zl_parse_error; /* last zil_parse() error */ uint64_t zl_parse_blk_seq; /* highest blk seq on last parse */ uint64_t zl_parse_lr_seq; /* highest lr seq on last parse */ uint64_t zl_parse_blk_count; /* number of blocks parsed */ uint64_t zl_parse_lr_count; /* number of log records parsed */ itxg_t zl_itxg[TXG_SIZE]; /* intent log txg chains */ list_t zl_itx_commit_list; /* itx list to be committed */ uint64_t zl_cur_used; /* current commit log size used */ list_t zl_lwb_list; /* in-flight log write list */ avl_tree_t zl_bp_tree; /* track bps during log parse */ clock_t zl_replay_time; /* lbolt of when replay started */ uint64_t zl_replay_blks; /* number of log blocks replayed */ zil_header_t zl_old_header; /* debugging aid */ uint_t zl_prev_blks[ZIL_PREV_BLKS]; /* size - sector rounded */ uint_t zl_prev_rotor; /* rotor for zl_prev[] */ txg_node_t zl_dirty_link; /* protected by dp_dirty_zilogs list */ uint64_t zl_dirty_max_txg; /* highest txg used to dirty zilog */ }; typedef struct zil_bp_node { dva_t zn_dva; avl_node_t zn_node; } zil_bp_node_t; /* * Maximum amount of write data that can be put into single log block. */ #define ZIL_MAX_LOG_DATA (SPA_OLD_MAXBLOCKSIZE - sizeof (zil_chain_t) - \ sizeof (lr_write_t)) /* * Maximum amount of log space we agree to waste to reduce number of * WR_NEED_COPY chunks to reduce zl_get_data() overhead (~12%). */ #define ZIL_MAX_WASTE_SPACE (ZIL_MAX_LOG_DATA / 8) /* * Maximum amount of write data for WR_COPIED. Fall back to WR_NEED_COPY * as more space efficient if we can't fit at least two log records into * maximum sized log block. */ #define ZIL_MAX_COPIED_DATA ((SPA_OLD_MAXBLOCKSIZE - \ sizeof (zil_chain_t)) / 2 - sizeof (lr_write_t)) #ifdef __cplusplus } #endif #endif /* _SYS_ZIL_IMPL_H */
