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