include/sys/spa_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or https://opensource.org/licenses/CDDL-1.0.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2011, 2019 by Delphix. All rights reserved.
  24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  25  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  26  * Copyright 2013 Saso Kiselkov. All rights reserved.
  27  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
  28  * Copyright (c) 2017, Intel Corporation.
  29  * Copyright (c) 2019 Datto Inc.
  30  */
  31
  32 #ifndef _SYS_SPA_IMPL_H
  33 #define _SYS_SPA_IMPL_H
  34
  35 #include <sys/spa.h>
  36 #include <sys/spa_checkpoint.h>
  37 #include <sys/spa_log_spacemap.h>
  38 #include <sys/vdev.h>
  39 #include <sys/vdev_rebuild.h>
  40 #include <sys/vdev_removal.h>
  41 #include <sys/vdev_raidz.h>
  42 #include <sys/metaslab.h>
  43 #include <sys/dmu.h>
  44 #include <sys/dsl_pool.h>
  45 #include <sys/uberblock_impl.h>
  46 #include <sys/zfs_context.h>
  47 #include <sys/avl.h>
  48 #include <sys/zfs_refcount.h>
  49 #include <sys/bplist.h>
  50 #include <sys/bpobj.h>
  51 #include <sys/dsl_crypt.h>
  52 #include <sys/zfeature.h>
  53 #include <sys/zthr.h>
  54 #include <sys/dsl_deadlist.h>
  55 #include <zfeature_common.h>
  56
  57 #ifdef  __cplusplus
  58 extern "C" {
  59 #endif
  60
  61 typedef struct spa_alloc {
  62         kmutex_t        spaa_lock;
  63         avl_tree_t      spaa_tree;
  64 } ____cacheline_aligned spa_alloc_t;
  65
  66 typedef struct spa_error_entry {
  67         zbookmark_phys_t        se_bookmark;
  68         char                    *se_name;
  69         avl_node_t              se_avl;
  70         zbookmark_err_phys_t    se_zep;         /* not accounted in avl_find */
  71 } spa_error_entry_t;
  72
  73 typedef struct spa_history_phys {
  74         uint64_t sh_pool_create_len;    /* ending offset of zpool create */
  75         uint64_t sh_phys_max_off;       /* physical EOF */
  76         uint64_t sh_bof;                /* logical BOF */
  77         uint64_t sh_eof;                /* logical EOF */
  78         uint64_t sh_records_lost;       /* num of records overwritten */
  79 } spa_history_phys_t;
  80
  81 /*
  82  * All members must be uint64_t, for byteswap purposes.
  83  */
  84 typedef struct spa_removing_phys {
  85         uint64_t sr_state; /* dsl_scan_state_t */
  86
  87         /*
  88          * The vdev ID that we most recently attempted to remove,
  89          * or -1 if no removal has been attempted.
  90          */
  91         uint64_t sr_removing_vdev;
  92
  93         /*
  94          * The vdev ID that we most recently successfully removed,
  95          * or -1 if no devices have been removed.
  96          */
  97         uint64_t sr_prev_indirect_vdev;
  98
  99         uint64_t sr_start_time;
 100         uint64_t sr_end_time;
 101
 102         /*
 103          * Note that we can not use the space map's or indirect mapping's
 104          * accounting as a substitute for these values, because we need to
 105          * count frees of not-yet-copied data as though it did the copy.
 106          * Otherwise, we could get into a situation where copied > to_copy,
 107          * or we complete before copied == to_copy.
 108          */
 109         uint64_t sr_to_copy; /* bytes that need to be copied */
 110         uint64_t sr_copied; /* bytes that have been copied or freed */
 111 } spa_removing_phys_t;
 112
 113 /*
 114  * This struct is stored as an entry in the DMU_POOL_DIRECTORY_OBJECT
 115  * (with key DMU_POOL_CONDENSING_INDIRECT).  It is present if a condense
 116  * of an indirect vdev's mapping object is in progress.
 117  */
 118 typedef struct spa_condensing_indirect_phys {
 119         /*
 120          * The vdev ID of the indirect vdev whose indirect mapping is
 121          * being condensed.
 122          */
 123         uint64_t        scip_vdev;
 124
 125         /*
 126          * The vdev's old obsolete spacemap.  This spacemap's contents are
 127          * being integrated into the new mapping.
 128          */
 129         uint64_t        scip_prev_obsolete_sm_object;
 130
 131         /*
 132          * The new mapping object that is being created.
 133          */
 134         uint64_t        scip_next_mapping_object;
 135 } spa_condensing_indirect_phys_t;
 136
 137 struct spa_aux_vdev {
 138         uint64_t        sav_object;             /* MOS object for device list */
 139         nvlist_t        *sav_config;            /* cached device config */
 140         vdev_t          **sav_vdevs;            /* devices */
 141         int             sav_count;              /* number devices */
 142         boolean_t       sav_sync;               /* sync the device list */
 143         nvlist_t        **sav_pending;          /* pending device additions */
 144         uint_t          sav_npending;           /* # pending devices */
 145 };
 146
 147 typedef struct spa_config_lock {
 148         kmutex_t        scl_lock;
 149         kthread_t       *scl_writer;
 150         int             scl_write_wanted;
 151         int             scl_count;
 152         kcondvar_t      scl_cv;
 153 } ____cacheline_aligned spa_config_lock_t;
 154
 155 typedef struct spa_config_dirent {
 156         list_node_t     scd_link;
 157         char            *scd_path;
 158 } spa_config_dirent_t;
 159
 160 typedef enum zio_taskq_type {
 161         ZIO_TASKQ_ISSUE = 0,
 162         ZIO_TASKQ_ISSUE_HIGH,
 163         ZIO_TASKQ_INTERRUPT,
 164         ZIO_TASKQ_INTERRUPT_HIGH,
 165         ZIO_TASKQ_TYPES
 166 } zio_taskq_type_t;
 167
 168 /*
 169  * State machine for the zpool-poolname process.  The states transitions
 170  * are done as follows:
 171  *
 172  *      From               To                   Routine
 173  *      PROC_NONE       -> PROC_CREATED         spa_activate()
 174  *      PROC_CREATED    -> PROC_ACTIVE          spa_thread()
 175  *      PROC_ACTIVE     -> PROC_DEACTIVATE      spa_deactivate()
 176  *      PROC_DEACTIVATE -> PROC_GONE            spa_thread()
 177  *      PROC_GONE       -> PROC_NONE            spa_deactivate()
 178  */
 179 typedef enum spa_proc_state {
 180         SPA_PROC_NONE,          /* spa_proc = &p0, no process created */
 181         SPA_PROC_CREATED,       /* spa_activate() has proc, is waiting */
 182         SPA_PROC_ACTIVE,        /* taskqs created, spa_proc set */
 183         SPA_PROC_DEACTIVATE,    /* spa_deactivate() requests process exit */
 184         SPA_PROC_GONE           /* spa_thread() is exiting, spa_proc = &p0 */
 185 } spa_proc_state_t;
 186
 187 typedef struct spa_taskqs {
 188         uint_t stqs_count;
 189         taskq_t **stqs_taskq;
 190 } spa_taskqs_t;
 191
 192 /* one for each thread in the spa sync taskq */
 193 typedef struct spa_syncthread_info {
 194         kthread_t       *sti_thread;
 195         taskq_t         *sti_wr_iss_tq;         /* assigned wr_iss taskq */
 196 } spa_syncthread_info_t;
 197
 198 typedef enum spa_all_vdev_zap_action {
 199         AVZ_ACTION_NONE = 0,
 200         AVZ_ACTION_DESTROY,     /* Destroy all per-vdev ZAPs and the AVZ. */
 201         AVZ_ACTION_REBUILD,     /* Populate the new AVZ, see spa_avz_rebuild */
 202         AVZ_ACTION_INITIALIZE
 203 } spa_avz_action_t;
 204
 205 typedef enum spa_config_source {
 206         SPA_CONFIG_SRC_NONE = 0,
 207         SPA_CONFIG_SRC_SCAN,            /* scan of path (default: /dev/dsk) */
 208         SPA_CONFIG_SRC_CACHEFILE,       /* any cachefile */
 209         SPA_CONFIG_SRC_TRYIMPORT,       /* returned from call to tryimport */
 210         SPA_CONFIG_SRC_SPLIT,           /* new pool in a pool split */
 211         SPA_CONFIG_SRC_MOS              /* MOS, but not always from right txg */
 212 } spa_config_source_t;
 213
 214 struct spa {
 215         /*
 216          * Fields protected by spa_namespace_lock.
 217          */
 218         char            spa_name[ZFS_MAX_DATASET_NAME_LEN];     /* pool name */
 219         char            *spa_comment;           /* comment */
 220         avl_node_t      spa_avl;                /* node in spa_namespace_avl */
 221         nvlist_t        *spa_config;            /* last synced config */
 222         nvlist_t        *spa_config_syncing;    /* currently syncing config */
 223         nvlist_t        *spa_config_splitting;  /* config for splitting */
 224         nvlist_t        *spa_load_info;         /* info and errors from load */
 225         uint64_t        spa_config_txg;         /* txg of last config change */
 226         uint32_t        spa_sync_pass;          /* iterate-to-convergence */
 227         pool_state_t    spa_state;              /* pool state */
 228         int             spa_inject_ref;         /* injection references */
 229         uint8_t         spa_sync_on;            /* sync threads are running */
 230         spa_load_state_t spa_load_state;        /* current load operation */
 231         boolean_t       spa_indirect_vdevs_loaded; /* mappings loaded? */
 232         boolean_t       spa_trust_config;       /* do we trust vdev tree? */
 233         boolean_t       spa_is_splitting;       /* in the middle of a split? */
 234         spa_config_source_t spa_config_source;  /* where config comes from? */
 235         uint64_t        spa_import_flags;       /* import specific flags */
 236         spa_taskqs_t    spa_zio_taskq[ZIO_TYPES][ZIO_TASKQ_TYPES];
 237         dsl_pool_t      *spa_dsl_pool;
 238         boolean_t       spa_is_initializing;    /* true while opening pool */
 239         boolean_t       spa_is_exporting;       /* true while exporting pool */
 240         metaslab_class_t *spa_normal_class;     /* normal data class */
 241         metaslab_class_t *spa_log_class;        /* intent log data class */
 242         metaslab_class_t *spa_embedded_log_class; /* log on normal vdevs */
 243         metaslab_class_t *spa_special_class;    /* special allocation class */
 244         metaslab_class_t *spa_dedup_class;      /* dedup allocation class */
 245         uint64_t        spa_first_txg;          /* first txg after spa_open() */
 246         uint64_t        spa_final_txg;          /* txg of export/destroy */
 247         uint64_t        spa_freeze_txg;         /* freeze pool at this txg */
 248         uint64_t        spa_load_max_txg;       /* best initial ub_txg */
 249         uint64_t        spa_claim_max_txg;      /* highest claimed birth txg */
 250         inode_timespec_t spa_loaded_ts;         /* 1st successful open time */
 251         objset_t        *spa_meta_objset;       /* copy of dp->dp_meta_objset */
 252         kmutex_t        spa_evicting_os_lock;   /* Evicting objset list lock */
 253         list_t          spa_evicting_os_list;   /* Objsets being evicted. */
 254         kcondvar_t      spa_evicting_os_cv;     /* Objset Eviction Completion */
 255         txg_list_t      spa_vdev_txg_list;      /* per-txg dirty vdev list */
 256         vdev_t          *spa_root_vdev;         /* top-level vdev container */
 257         uint64_t        spa_min_ashift;         /* of vdevs in normal class */
 258         uint64_t        spa_max_ashift;         /* of vdevs in normal class */
 259         uint64_t        spa_min_alloc;          /* of vdevs in normal class */
 260         uint64_t        spa_gcd_alloc;          /* of vdevs in normal class */
 261         uint64_t        spa_config_guid;        /* config pool guid */
 262         uint64_t        spa_load_guid;          /* spa_load initialized guid */
 263         uint64_t        spa_last_synced_guid;   /* last synced guid */
 264         list_t          spa_config_dirty_list;  /* vdevs with dirty config */
 265         list_t          spa_state_dirty_list;   /* vdevs with dirty state */
 266         /*
 267          * spa_allocs is an array, whose lengths is stored in spa_alloc_count.
 268          * There is one tree and one lock for each allocator, to help improve
 269          * allocation performance in write-heavy workloads.
 270          */
 271         spa_alloc_t     *spa_allocs;
 272         int             spa_alloc_count;
 273         int             spa_active_allocator;   /* selectable allocator */
 274
 275         /* per-allocator sync thread taskqs */
 276         taskq_t         *spa_sync_tq;
 277         spa_syncthread_info_t *spa_syncthreads;
 278
 279         spa_aux_vdev_t  spa_spares;             /* hot spares */
 280         spa_aux_vdev_t  spa_l2cache;            /* L2ARC cache devices */
 281         nvlist_t        *spa_label_features;    /* Features for reading MOS */
 282         uint64_t        spa_config_object;      /* MOS object for pool config */
 283         uint64_t        spa_config_generation;  /* config generation number */
 284         uint64_t        spa_syncing_txg;        /* txg currently syncing */
 285         bpobj_t         spa_deferred_bpobj;     /* deferred-free bplist */
 286         bplist_t        spa_free_bplist[TXG_SIZE]; /* bplist of stuff to free */
 287         zio_cksum_salt_t spa_cksum_salt;        /* secret salt for cksum */
 288         /* checksum context templates */
 289         kmutex_t        spa_cksum_tmpls_lock;
 290         void            *spa_cksum_tmpls[ZIO_CHECKSUM_FUNCTIONS];
 291         uberblock_t     spa_ubsync;             /* last synced uberblock */
 292         uberblock_t     spa_uberblock;          /* current uberblock */
 293         boolean_t       spa_extreme_rewind;     /* rewind past deferred frees */
 294         kmutex_t        spa_scrub_lock;         /* resilver/scrub lock */
 295         uint64_t        spa_scrub_inflight;     /* in-flight scrub bytes */
 296
 297         /* in-flight verification bytes */
 298         uint64_t        spa_load_verify_bytes;
 299         kcondvar_t      spa_scrub_io_cv;        /* scrub I/O completion */
 300         uint8_t         spa_scrub_active;       /* active or suspended? */
 301         uint8_t         spa_scrub_type;         /* type of scrub we're doing */
 302         uint8_t         spa_scrub_finished;     /* indicator to rotate logs */
 303         uint8_t         spa_scrub_started;      /* started since last boot */
 304         uint8_t         spa_scrub_reopen;       /* scrub doing vdev_reopen */
 305         uint64_t        spa_scan_pass_start;    /* start time per pass/reboot */
 306         uint64_t        spa_scan_pass_scrub_pause; /* scrub pause time */
 307         uint64_t        spa_scan_pass_scrub_spent_paused; /* total paused */
 308         uint64_t        spa_scan_pass_exam;     /* examined bytes per pass */
 309         uint64_t        spa_scan_pass_issued;   /* issued bytes per pass */
 310
 311         /* error scrub pause time in milliseconds */
 312         uint64_t        spa_scan_pass_errorscrub_pause;
 313         /* total error scrub paused time in milliseconds */
 314         uint64_t        spa_scan_pass_errorscrub_spent_paused;
 315         /*
 316          * We are in the middle of a resilver, and another resilver
 317          * is needed once this one completes. This is set iff any
 318          * vdev_resilver_deferred is set.
 319          */
 320         boolean_t       spa_resilver_deferred;
 321         kmutex_t        spa_async_lock;         /* protect async state */
 322         kthread_t       *spa_async_thread;      /* thread doing async task */
 323         int             spa_async_suspended;    /* async tasks suspended */
 324         kcondvar_t      spa_async_cv;           /* wait for thread_exit() */
 325         uint16_t        spa_async_tasks;        /* async task mask */
 326         uint64_t        spa_missing_tvds;       /* unopenable tvds on load */
 327         uint64_t        spa_missing_tvds_allowed; /* allow loading spa? */
 328
 329         uint64_t        spa_nonallocating_dspace;
 330         spa_removing_phys_t spa_removing_phys;
 331         spa_vdev_removal_t *spa_vdev_removal;
 332
 333         spa_condensing_indirect_phys_t  spa_condensing_indirect_phys;
 334         spa_condensing_indirect_t       *spa_condensing_indirect;
 335         zthr_t          *spa_condense_zthr;     /* zthr doing condense. */
 336
 337         vdev_raidz_expand_t     *spa_raidz_expand;
 338         zthr_t          *spa_raidz_expand_zthr;
 339
 340         uint64_t        spa_checkpoint_txg;     /* the txg of the checkpoint */
 341         spa_checkpoint_info_t spa_checkpoint_info; /* checkpoint accounting */
 342         zthr_t          *spa_checkpoint_discard_zthr;
 343
 344         space_map_t     *spa_syncing_log_sm;    /* current log space map */
 345         avl_tree_t      spa_sm_logs_by_txg;
 346         kmutex_t        spa_flushed_ms_lock;    /* for metaslabs_by_flushed */
 347         avl_tree_t      spa_metaslabs_by_flushed;
 348         spa_unflushed_stats_t   spa_unflushed_stats;
 349         list_t          spa_log_summary;
 350         uint64_t        spa_log_flushall_txg;
 351
 352         zthr_t          *spa_livelist_delete_zthr; /* deleting livelists */
 353         zthr_t          *spa_livelist_condense_zthr; /* condensing livelists */
 354         uint64_t        spa_livelists_to_delete; /* set of livelists to free */
 355         livelist_condense_entry_t       spa_to_condense; /* next to condense */
 356
 357         char            *spa_root;              /* alternate root directory */
 358         uint64_t        spa_ena;                /* spa-wide ereport ENA */
 359         int             spa_last_open_failed;   /* error if last open failed */
 360         uint64_t        spa_last_ubsync_txg;    /* "best" uberblock txg */
 361         uint64_t        spa_last_ubsync_txg_ts; /* timestamp from that ub */
 362         uint64_t        spa_load_txg;           /* ub txg that loaded */
 363         uint64_t        spa_load_txg_ts;        /* timestamp from that ub */
 364         uint64_t        spa_load_meta_errors;   /* verify metadata err count */
 365         uint64_t        spa_load_data_errors;   /* verify data err count */
 366         uint64_t        spa_verify_min_txg;     /* start txg of verify scrub */
 367         kmutex_t        spa_errlog_lock;        /* error log lock */
 368         uint64_t        spa_errlog_last;        /* last error log object */
 369         uint64_t        spa_errlog_scrub;       /* scrub error log object */
 370         kmutex_t        spa_errlist_lock;       /* error list/ereport lock */
 371         avl_tree_t      spa_errlist_last;       /* last error list */
 372         avl_tree_t      spa_errlist_scrub;      /* scrub error list */
 373         avl_tree_t      spa_errlist_healed;     /* list of healed blocks */
 374         uint64_t        spa_deflate;            /* should we deflate? */
 375         uint64_t        spa_history;            /* history object */
 376         kmutex_t        spa_history_lock;       /* history lock */
 377         vdev_t          *spa_pending_vdev;      /* pending vdev additions */
 378         kmutex_t        spa_props_lock;         /* property lock */
 379         uint64_t        spa_pool_props_object;  /* object for properties */
 380         uint64_t        spa_bootfs;             /* default boot filesystem */
 381         uint64_t        spa_failmode;           /* failure mode for the pool */
 382         uint64_t        spa_deadman_failmode;   /* failure mode for deadman */
 383         uint64_t        spa_delegation;         /* delegation on/off */
 384         list_t          spa_config_list;        /* previous cache file(s) */
 385         /* per-CPU array of root of async I/O: */
 386         zio_t           **spa_async_zio_root;
 387         zio_t           *spa_suspend_zio_root;  /* root of all suspended I/O */
 388         zio_t           *spa_txg_zio[TXG_SIZE]; /* spa_sync() waits for this */
 389         kmutex_t        spa_suspend_lock;       /* protects suspend_zio_root */
 390         kcondvar_t      spa_suspend_cv;         /* notification of resume */
 391         zio_suspend_reason_t    spa_suspended;  /* pool is suspended */
 392         uint8_t         spa_claiming;           /* pool is doing zil_claim() */
 393         boolean_t       spa_is_root;            /* pool is root */
 394         int             spa_minref;             /* num refs when first opened */
 395         spa_mode_t      spa_mode;               /* SPA_MODE_{READ|WRITE} */
 396         boolean_t       spa_read_spacemaps;     /* spacemaps available if ro */
 397         spa_log_state_t spa_log_state;          /* log state */
 398         uint64_t        spa_autoexpand;         /* lun expansion on/off */
 399         ddt_t           *spa_ddt[ZIO_CHECKSUM_FUNCTIONS]; /* in-core DDTs */
 400         uint64_t        spa_ddt_stat_object;    /* DDT statistics */
 401         uint64_t        spa_dedup_dspace;       /* Cache get_dedup_dspace() */
 402         uint64_t        spa_dedup_checksum;     /* default dedup checksum */
 403         uint64_t        spa_dspace;             /* dspace in normal class */
 404         struct brt      *spa_brt;               /* in-core BRT */
 405         kmutex_t        spa_vdev_top_lock;      /* dueling offline/remove */
 406         kmutex_t        spa_proc_lock;          /* protects spa_proc* */
 407         kcondvar_t      spa_proc_cv;            /* spa_proc_state transitions */
 408         spa_proc_state_t spa_proc_state;        /* see definition */
 409         proc_t          *spa_proc;              /* "zpool-poolname" process */
 410         uintptr_t       spa_did;                /* if procp != p0, did of t1 */
 411         boolean_t       spa_autoreplace;        /* autoreplace set in open */
 412         int             spa_vdev_locks;         /* locks grabbed */
 413         uint64_t        spa_creation_version;   /* version at pool creation */
 414         uint64_t        spa_prev_software_version; /* See ub_software_version */
 415         uint64_t        spa_feat_for_write_obj; /* required to write to pool */
 416         uint64_t        spa_feat_for_read_obj;  /* required to read from pool */
 417         uint64_t        spa_feat_desc_obj;      /* Feature descriptions */
 418         uint64_t        spa_feat_enabled_txg_obj; /* Feature enabled txg */
 419         kmutex_t        spa_feat_stats_lock;    /* protects spa_feat_stats */
 420         nvlist_t        *spa_feat_stats;        /* Cache of enabled features */
 421         /* cache feature refcounts */
 422         uint64_t        spa_feat_refcount_cache[SPA_FEATURES];
 423         taskqid_t       spa_deadman_tqid;       /* Task id */
 424         uint64_t        spa_deadman_calls;      /* number of deadman calls */
 425         hrtime_t        spa_sync_starttime;     /* starting time of spa_sync */
 426         uint64_t        spa_deadman_synctime;   /* deadman sync expiration */
 427         uint64_t        spa_deadman_ziotime;    /* deadman zio expiration */
 428         uint64_t        spa_all_vdev_zaps;      /* ZAP of per-vd ZAP obj #s */
 429         spa_avz_action_t        spa_avz_action; /* destroy/rebuild AVZ? */
 430         uint64_t        spa_autotrim;           /* automatic background trim? */
 431         uint64_t        spa_errata;             /* errata issues detected */
 432         spa_stats_t     spa_stats;              /* assorted spa statistics */
 433         spa_keystore_t  spa_keystore;           /* loaded crypto keys */
 434
 435         /* arc_memory_throttle() parameters during low memory condition */
 436         uint64_t        spa_lowmem_page_load;   /* memory load during txg */
 437         uint64_t        spa_lowmem_last_txg;    /* txg window start */
 438
 439         hrtime_t        spa_ccw_fail_time;      /* Conf cache write fail time */
 440         taskq_t         *spa_zvol_taskq;        /* Taskq for minor management */
 441         taskq_t         *spa_metaslab_taskq;    /* Taskq for metaslab preload */
 442         taskq_t         *spa_prefetch_taskq;    /* Taskq for prefetch threads */
 443         taskq_t         *spa_upgrade_taskq;     /* Taskq for upgrade jobs */
 444         uint64_t        spa_multihost;          /* multihost aware (mmp) */
 445         mmp_thread_t    spa_mmp;                /* multihost mmp thread */
 446         list_t          spa_leaf_list;          /* list of leaf vdevs */
 447         uint64_t        spa_leaf_list_gen;      /* track leaf_list changes */
 448         uint32_t        spa_hostid;             /* cached system hostid */
 449
 450         /* synchronization for threads in spa_wait */
 451         kmutex_t        spa_activities_lock;
 452         kcondvar_t      spa_activities_cv;
 453         kcondvar_t      spa_waiters_cv;
 454         int             spa_waiters;            /* number of waiting threads */
 455         boolean_t       spa_waiters_cancel;     /* waiters should return */
 456
 457         char            *spa_compatibility;     /* compatibility file(s) */
 458
 459         /*
 460          * spa_refcount & spa_config_lock must be the last elements
 461          * because zfs_refcount_t changes size based on compilation options.
 462          * In order for the MDB module to function correctly, the other
 463          * fields must remain in the same location.
 464          */
 465         spa_config_lock_t spa_config_lock[SCL_LOCKS]; /* config changes */
 466         zfs_refcount_t  spa_refcount;           /* number of opens */
 467 };
 468
 469 extern char *spa_config_path;
 470 extern const char *zfs_deadman_failmode;
 471 extern uint_t spa_slop_shift;
 472 extern void spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 473     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent, zio_t *zio);
 474 extern void spa_taskq_dispatch_sync(spa_t *, zio_type_t t, zio_taskq_type_t q,
 475     task_func_t *func, void *arg, uint_t flags);
 476 extern void spa_load_spares(spa_t *spa);
 477 extern void spa_load_l2cache(spa_t *spa);
 478 extern sysevent_t *spa_event_create(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl,
 479     const char *name);
 480 extern void spa_event_post(sysevent_t *ev);
 481 extern int param_set_deadman_failmode_common(const char *val);
 482 extern void spa_set_deadman_synctime(hrtime_t ns);
 483 extern void spa_set_deadman_ziotime(hrtime_t ns);
 484 extern const char *spa_history_zone(void);
 485 extern const char *zfs_active_allocator;
 486 extern int param_set_active_allocator_common(const char *val);
 487
 488 #ifdef  __cplusplus
 489 }
 490 #endif
 491
 492 #endif  /* _SYS_SPA_IMPL_H */