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5056 ZFS deadlock on db_mtx and dn_holds
Reviewed by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
    
      
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          --- old/usr/src/uts/common/fs/zfs/spa_misc.c
          +++ new/usr/src/uts/common/fs/zfs/spa_misc.c
   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  
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  15   15   * If applicable, add the following below this CDDL HEADER, with the
  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *
  19   19   * CDDL HEADER END
  20   20   */
  21   21  /*
  22   22   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23   23   * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
  24   24   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
       25 + * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  25   26   */
  26   27  
  27   28  #include <sys/zfs_context.h>
  28   29  #include <sys/spa_impl.h>
  29   30  #include <sys/spa_boot.h>
  30   31  #include <sys/zio.h>
  31   32  #include <sys/zio_checksum.h>
  32   33  #include <sys/zio_compress.h>
  33   34  #include <sys/dmu.h>
  34   35  #include <sys/dmu_tx.h>
  35   36  #include <sys/zap.h>
  36   37  #include <sys/zil.h>
  37   38  #include <sys/vdev_impl.h>
  38   39  #include <sys/metaslab.h>
  39   40  #include <sys/uberblock_impl.h>
  40   41  #include <sys/txg.h>
  41   42  #include <sys/avl.h>
  42   43  #include <sys/unique.h>
  43   44  #include <sys/dsl_pool.h>
  44   45  #include <sys/dsl_dir.h>
  45   46  #include <sys/dsl_prop.h>
  46   47  #include <sys/dsl_scan.h>
  47   48  #include <sys/fs/zfs.h>
  48   49  #include <sys/metaslab_impl.h>
  49   50  #include <sys/arc.h>
  50   51  #include <sys/ddt.h>
  51   52  #include "zfs_prop.h"
  52   53  #include "zfeature_common.h"
  53   54  
  54   55  /*
  55   56   * SPA locking
  56   57   *
  57   58   * There are four basic locks for managing spa_t structures:
  58   59   *
  59   60   * spa_namespace_lock (global mutex)
  60   61   *
  61   62   *      This lock must be acquired to do any of the following:
  62   63   *
  63   64   *              - Lookup a spa_t by name
  64   65   *              - Add or remove a spa_t from the namespace
  65   66   *              - Increase spa_refcount from non-zero
  66   67   *              - Check if spa_refcount is zero
  67   68   *              - Rename a spa_t
  68   69   *              - add/remove/attach/detach devices
  69   70   *              - Held for the duration of create/destroy/import/export
  70   71   *
  71   72   *      It does not need to handle recursion.  A create or destroy may
  72   73   *      reference objects (files or zvols) in other pools, but by
  73   74   *      definition they must have an existing reference, and will never need
  74   75   *      to lookup a spa_t by name.
  75   76   *
  76   77   * spa_refcount (per-spa refcount_t protected by mutex)
  77   78   *
  78   79   *      This reference count keep track of any active users of the spa_t.  The
  79   80   *      spa_t cannot be destroyed or freed while this is non-zero.  Internally,
  80   81   *      the refcount is never really 'zero' - opening a pool implicitly keeps
  81   82   *      some references in the DMU.  Internally we check against spa_minref, but
  82   83   *      present the image of a zero/non-zero value to consumers.
  83   84   *
  84   85   * spa_config_lock[] (per-spa array of rwlocks)
  85   86   *
  86   87   *      This protects the spa_t from config changes, and must be held in
  87   88   *      the following circumstances:
  88   89   *
  89   90   *              - RW_READER to perform I/O to the spa
  90   91   *              - RW_WRITER to change the vdev config
  91   92   *
  92   93   * The locking order is fairly straightforward:
  93   94   *
  94   95   *              spa_namespace_lock      ->      spa_refcount
  95   96   *
  96   97   *      The namespace lock must be acquired to increase the refcount from 0
  97   98   *      or to check if it is zero.
  98   99   *
  99  100   *              spa_refcount            ->      spa_config_lock[]
 100  101   *
 101  102   *      There must be at least one valid reference on the spa_t to acquire
 102  103   *      the config lock.
 103  104   *
 104  105   *              spa_namespace_lock      ->      spa_config_lock[]
 105  106   *
 106  107   *      The namespace lock must always be taken before the config lock.
 107  108   *
 108  109   *
 109  110   * The spa_namespace_lock can be acquired directly and is globally visible.
 110  111   *
 111  112   * The namespace is manipulated using the following functions, all of which
 112  113   * require the spa_namespace_lock to be held.
 113  114   *
 114  115   *      spa_lookup()            Lookup a spa_t by name.
 115  116   *
 116  117   *      spa_add()               Create a new spa_t in the namespace.
 117  118   *
 118  119   *      spa_remove()            Remove a spa_t from the namespace.  This also
 119  120   *                              frees up any memory associated with the spa_t.
 120  121   *
 121  122   *      spa_next()              Returns the next spa_t in the system, or the
 122  123   *                              first if NULL is passed.
 123  124   *
 124  125   *      spa_evict_all()         Shutdown and remove all spa_t structures in
 125  126   *                              the system.
 126  127   *
 127  128   *      spa_guid_exists()       Determine whether a pool/device guid exists.
 128  129   *
 129  130   * The spa_refcount is manipulated using the following functions:
 130  131   *
 131  132   *      spa_open_ref()          Adds a reference to the given spa_t.  Must be
 132  133   *                              called with spa_namespace_lock held if the
 133  134   *                              refcount is currently zero.
 134  135   *
 135  136   *      spa_close()             Remove a reference from the spa_t.  This will
 136  137   *                              not free the spa_t or remove it from the
 137  138   *                              namespace.  No locking is required.
 138  139   *
 139  140   *      spa_refcount_zero()     Returns true if the refcount is currently
 140  141   *                              zero.  Must be called with spa_namespace_lock
 141  142   *                              held.
 142  143   *
 143  144   * The spa_config_lock[] is an array of rwlocks, ordered as follows:
 144  145   * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
 145  146   * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
 146  147   *
 147  148   * To read the configuration, it suffices to hold one of these locks as reader.
 148  149   * To modify the configuration, you must hold all locks as writer.  To modify
 149  150   * vdev state without altering the vdev tree's topology (e.g. online/offline),
 150  151   * you must hold SCL_STATE and SCL_ZIO as writer.
 151  152   *
 152  153   * We use these distinct config locks to avoid recursive lock entry.
 153  154   * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
 154  155   * block allocations (SCL_ALLOC), which may require reading space maps
 155  156   * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
 156  157   *
 157  158   * The spa config locks cannot be normal rwlocks because we need the
 158  159   * ability to hand off ownership.  For example, SCL_ZIO is acquired
 159  160   * by the issuing thread and later released by an interrupt thread.
 160  161   * They do, however, obey the usual write-wanted semantics to prevent
 161  162   * writer (i.e. system administrator) starvation.
 162  163   *
 163  164   * The lock acquisition rules are as follows:
 164  165   *
 165  166   * SCL_CONFIG
 166  167   *      Protects changes to the vdev tree topology, such as vdev
 167  168   *      add/remove/attach/detach.  Protects the dirty config list
 168  169   *      (spa_config_dirty_list) and the set of spares and l2arc devices.
 169  170   *
 170  171   * SCL_STATE
 171  172   *      Protects changes to pool state and vdev state, such as vdev
 172  173   *      online/offline/fault/degrade/clear.  Protects the dirty state list
 173  174   *      (spa_state_dirty_list) and global pool state (spa_state).
 174  175   *
 175  176   * SCL_ALLOC
 176  177   *      Protects changes to metaslab groups and classes.
 177  178   *      Held as reader by metaslab_alloc() and metaslab_claim().
 178  179   *
 179  180   * SCL_ZIO
 180  181   *      Held by bp-level zios (those which have no io_vd upon entry)
 181  182   *      to prevent changes to the vdev tree.  The bp-level zio implicitly
 182  183   *      protects all of its vdev child zios, which do not hold SCL_ZIO.
 183  184   *
 184  185   * SCL_FREE
 185  186   *      Protects changes to metaslab groups and classes.
 186  187   *      Held as reader by metaslab_free().  SCL_FREE is distinct from
 187  188   *      SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
 188  189   *      blocks in zio_done() while another i/o that holds either
 189  190   *      SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
 190  191   *
 191  192   * SCL_VDEV
 192  193   *      Held as reader to prevent changes to the vdev tree during trivial
 193  194   *      inquiries such as bp_get_dsize().  SCL_VDEV is distinct from the
 194  195   *      other locks, and lower than all of them, to ensure that it's safe
 195  196   *      to acquire regardless of caller context.
 196  197   *
 197  198   * In addition, the following rules apply:
 198  199   *
 199  200   * (a)  spa_props_lock protects pool properties, spa_config and spa_config_list.
 200  201   *      The lock ordering is SCL_CONFIG > spa_props_lock.
 201  202   *
 202  203   * (b)  I/O operations on leaf vdevs.  For any zio operation that takes
 203  204   *      an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
 204  205   *      or zio_write_phys() -- the caller must ensure that the config cannot
 205  206   *      cannot change in the interim, and that the vdev cannot be reopened.
 206  207   *      SCL_STATE as reader suffices for both.
 207  208   *
 208  209   * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
 209  210   *
 210  211   *      spa_vdev_enter()        Acquire the namespace lock and the config lock
 211  212   *                              for writing.
 212  213   *
 213  214   *      spa_vdev_exit()         Release the config lock, wait for all I/O
 214  215   *                              to complete, sync the updated configs to the
 215  216   *                              cache, and release the namespace lock.
 216  217   *
 217  218   * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
 218  219   * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
 219  220   * locking is, always, based on spa_namespace_lock and spa_config_lock[].
 220  221   *
 221  222   * spa_rename() is also implemented within this file since it requires
 222  223   * manipulation of the namespace.
 223  224   */
 224  225  
 225  226  static avl_tree_t spa_namespace_avl;
 226  227  kmutex_t spa_namespace_lock;
 227  228  static kcondvar_t spa_namespace_cv;
 228  229  static int spa_active_count;
 229  230  int spa_max_replication_override = SPA_DVAS_PER_BP;
 230  231  
 231  232  static kmutex_t spa_spare_lock;
 232  233  static avl_tree_t spa_spare_avl;
 233  234  static kmutex_t spa_l2cache_lock;
 234  235  static avl_tree_t spa_l2cache_avl;
 235  236  
 236  237  kmem_cache_t *spa_buffer_pool;
 237  238  int spa_mode_global;
 238  239  
 239  240  #ifdef ZFS_DEBUG
 240  241  /* Everything except dprintf and spa is on by default in debug builds */
 241  242  int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA);
 242  243  #else
 243  244  int zfs_flags = 0;
 244  245  #endif
 245  246  
 246  247  /*
 247  248   * zfs_recover can be set to nonzero to attempt to recover from
 248  249   * otherwise-fatal errors, typically caused by on-disk corruption.  When
 249  250   * set, calls to zfs_panic_recover() will turn into warning messages.
 250  251   * This should only be used as a last resort, as it typically results
 251  252   * in leaked space, or worse.
 252  253   */
 253  254  boolean_t zfs_recover = B_FALSE;
 254  255  
 255  256  /*
 256  257   * If destroy encounters an EIO while reading metadata (e.g. indirect
 257  258   * blocks), space referenced by the missing metadata can not be freed.
 258  259   * Normally this causes the background destroy to become "stalled", as
 259  260   * it is unable to make forward progress.  While in this stalled state,
 260  261   * all remaining space to free from the error-encountering filesystem is
 261  262   * "temporarily leaked".  Set this flag to cause it to ignore the EIO,
 262  263   * permanently leak the space from indirect blocks that can not be read,
 263  264   * and continue to free everything else that it can.
 264  265   *
 265  266   * The default, "stalling" behavior is useful if the storage partially
 266  267   * fails (i.e. some but not all i/os fail), and then later recovers.  In
 267  268   * this case, we will be able to continue pool operations while it is
 268  269   * partially failed, and when it recovers, we can continue to free the
 269  270   * space, with no leaks.  However, note that this case is actually
 270  271   * fairly rare.
 271  272   *
 272  273   * Typically pools either (a) fail completely (but perhaps temporarily,
 273  274   * e.g. a top-level vdev going offline), or (b) have localized,
 274  275   * permanent errors (e.g. disk returns the wrong data due to bit flip or
 275  276   * firmware bug).  In case (a), this setting does not matter because the
 276  277   * pool will be suspended and the sync thread will not be able to make
 277  278   * forward progress regardless.  In case (b), because the error is
 278  279   * permanent, the best we can do is leak the minimum amount of space,
 279  280   * which is what setting this flag will do.  Therefore, it is reasonable
 280  281   * for this flag to normally be set, but we chose the more conservative
 281  282   * approach of not setting it, so that there is no possibility of
 282  283   * leaking space in the "partial temporary" failure case.
 283  284   */
 284  285  boolean_t zfs_free_leak_on_eio = B_FALSE;
 285  286  
 286  287  /*
 287  288   * Expiration time in milliseconds. This value has two meanings. First it is
 288  289   * used to determine when the spa_deadman() logic should fire. By default the
 289  290   * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds.
 290  291   * Secondly, the value determines if an I/O is considered "hung". Any I/O that
 291  292   * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting
 292  293   * in a system panic.
 293  294   */
 294  295  uint64_t zfs_deadman_synctime_ms = 1000000ULL;
 295  296  
 296  297  /*
 297  298   * Check time in milliseconds. This defines the frequency at which we check
 298  299   * for hung I/O.
 299  300   */
 300  301  uint64_t zfs_deadman_checktime_ms = 5000ULL;
 301  302  
 302  303  /*
 303  304   * Override the zfs deadman behavior via /etc/system. By default the
 304  305   * deadman is enabled except on VMware and sparc deployments.
 305  306   */
 306  307  int zfs_deadman_enabled = -1;
 307  308  
 308  309  /*
 309  310   * The worst case is single-sector max-parity RAID-Z blocks, in which
 310  311   * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
 311  312   * times the size; so just assume that.  Add to this the fact that
 312  313   * we can have up to 3 DVAs per bp, and one more factor of 2 because
 313  314   * the block may be dittoed with up to 3 DVAs by ddt_sync().  All together,
 314  315   * the worst case is:
 315  316   *     (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24
 316  317   */
 317  318  int spa_asize_inflation = 24;
 318  319  
 319  320  /*
 320  321   * Normally, we don't allow the last 3.2% (1/(2^spa_slop_shift)) of space in
 321  322   * the pool to be consumed.  This ensures that we don't run the pool
 322  323   * completely out of space, due to unaccounted changes (e.g. to the MOS).
 323  324   * It also limits the worst-case time to allocate space.  If we have
 324  325   * less than this amount of free space, most ZPL operations (e.g. write,
 325  326   * create) will return ENOSPC.
 326  327   *
 327  328   * Certain operations (e.g. file removal, most administrative actions) can
 328  329   * use half the slop space.  They will only return ENOSPC if less than half
 329  330   * the slop space is free.  Typically, once the pool has less than the slop
 330  331   * space free, the user will use these operations to free up space in the pool.
 331  332   * These are the operations that call dsl_pool_adjustedsize() with the netfree
 332  333   * argument set to TRUE.
 333  334   *
 334  335   * A very restricted set of operations are always permitted, regardless of
 335  336   * the amount of free space.  These are the operations that call
 336  337   * dsl_sync_task(ZFS_SPACE_CHECK_NONE), e.g. "zfs destroy".  If these
 337  338   * operations result in a net increase in the amount of space used,
 338  339   * it is possible to run the pool completely out of space, causing it to
 339  340   * be permanently read-only.
 340  341   *
 341  342   * See also the comments in zfs_space_check_t.
 342  343   */
 343  344  int spa_slop_shift = 5;
 344  345  
 345  346  /*
 346  347   * ==========================================================================
 347  348   * SPA config locking
 348  349   * ==========================================================================
 349  350   */
 350  351  static void
 351  352  spa_config_lock_init(spa_t *spa)
 352  353  {
 353  354          for (int i = 0; i < SCL_LOCKS; i++) {
 354  355                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 355  356                  mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
 356  357                  cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
 357  358                  refcount_create_untracked(&scl->scl_count);
 358  359                  scl->scl_writer = NULL;
 359  360                  scl->scl_write_wanted = 0;
 360  361          }
 361  362  }
 362  363  
 363  364  static void
 364  365  spa_config_lock_destroy(spa_t *spa)
 365  366  {
 366  367          for (int i = 0; i < SCL_LOCKS; i++) {
 367  368                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 368  369                  mutex_destroy(&scl->scl_lock);
 369  370                  cv_destroy(&scl->scl_cv);
 370  371                  refcount_destroy(&scl->scl_count);
 371  372                  ASSERT(scl->scl_writer == NULL);
 372  373                  ASSERT(scl->scl_write_wanted == 0);
 373  374          }
 374  375  }
 375  376  
 376  377  int
 377  378  spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
 378  379  {
 379  380          for (int i = 0; i < SCL_LOCKS; i++) {
 380  381                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 381  382                  if (!(locks & (1 << i)))
 382  383                          continue;
 383  384                  mutex_enter(&scl->scl_lock);
 384  385                  if (rw == RW_READER) {
 385  386                          if (scl->scl_writer || scl->scl_write_wanted) {
 386  387                                  mutex_exit(&scl->scl_lock);
 387  388                                  spa_config_exit(spa, locks ^ (1 << i), tag);
 388  389                                  return (0);
 389  390                          }
 390  391                  } else {
 391  392                          ASSERT(scl->scl_writer != curthread);
 392  393                          if (!refcount_is_zero(&scl->scl_count)) {
 393  394                                  mutex_exit(&scl->scl_lock);
 394  395                                  spa_config_exit(spa, locks ^ (1 << i), tag);
 395  396                                  return (0);
 396  397                          }
 397  398                          scl->scl_writer = curthread;
 398  399                  }
 399  400                  (void) refcount_add(&scl->scl_count, tag);
 400  401                  mutex_exit(&scl->scl_lock);
 401  402          }
 402  403          return (1);
 403  404  }
 404  405  
 405  406  void
 406  407  spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
 407  408  {
 408  409          int wlocks_held = 0;
 409  410  
 410  411          ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
 411  412  
 412  413          for (int i = 0; i < SCL_LOCKS; i++) {
 413  414                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 414  415                  if (scl->scl_writer == curthread)
 415  416                          wlocks_held |= (1 << i);
 416  417                  if (!(locks & (1 << i)))
 417  418                          continue;
 418  419                  mutex_enter(&scl->scl_lock);
 419  420                  if (rw == RW_READER) {
 420  421                          while (scl->scl_writer || scl->scl_write_wanted) {
 421  422                                  cv_wait(&scl->scl_cv, &scl->scl_lock);
 422  423                          }
 423  424                  } else {
 424  425                          ASSERT(scl->scl_writer != curthread);
 425  426                          while (!refcount_is_zero(&scl->scl_count)) {
 426  427                                  scl->scl_write_wanted++;
 427  428                                  cv_wait(&scl->scl_cv, &scl->scl_lock);
 428  429                                  scl->scl_write_wanted--;
 429  430                          }
 430  431                          scl->scl_writer = curthread;
 431  432                  }
 432  433                  (void) refcount_add(&scl->scl_count, tag);
 433  434                  mutex_exit(&scl->scl_lock);
 434  435          }
 435  436          ASSERT(wlocks_held <= locks);
 436  437  }
 437  438  
 438  439  void
 439  440  spa_config_exit(spa_t *spa, int locks, void *tag)
 440  441  {
 441  442          for (int i = SCL_LOCKS - 1; i >= 0; i--) {
 442  443                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 443  444                  if (!(locks & (1 << i)))
 444  445                          continue;
 445  446                  mutex_enter(&scl->scl_lock);
 446  447                  ASSERT(!refcount_is_zero(&scl->scl_count));
 447  448                  if (refcount_remove(&scl->scl_count, tag) == 0) {
 448  449                          ASSERT(scl->scl_writer == NULL ||
 449  450                              scl->scl_writer == curthread);
 450  451                          scl->scl_writer = NULL; /* OK in either case */
 451  452                          cv_broadcast(&scl->scl_cv);
 452  453                  }
 453  454                  mutex_exit(&scl->scl_lock);
 454  455          }
 455  456  }
 456  457  
 457  458  int
 458  459  spa_config_held(spa_t *spa, int locks, krw_t rw)
 459  460  {
 460  461          int locks_held = 0;
 461  462  
 462  463          for (int i = 0; i < SCL_LOCKS; i++) {
 463  464                  spa_config_lock_t *scl = &spa->spa_config_lock[i];
 464  465                  if (!(locks & (1 << i)))
 465  466                          continue;
 466  467                  if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
 467  468                      (rw == RW_WRITER && scl->scl_writer == curthread))
 468  469                          locks_held |= 1 << i;
 469  470          }
 470  471  
 471  472          return (locks_held);
 472  473  }
 473  474  
 474  475  /*
 475  476   * ==========================================================================
 476  477   * SPA namespace functions
 477  478   * ==========================================================================
 478  479   */
 479  480  
 480  481  /*
 481  482   * Lookup the named spa_t in the AVL tree.  The spa_namespace_lock must be held.
 482  483   * Returns NULL if no matching spa_t is found.
 483  484   */
 484  485  spa_t *
 485  486  spa_lookup(const char *name)
 486  487  {
 487  488          static spa_t search;    /* spa_t is large; don't allocate on stack */
 488  489          spa_t *spa;
 489  490          avl_index_t where;
 490  491          char *cp;
 491  492  
 492  493          ASSERT(MUTEX_HELD(&spa_namespace_lock));
 493  494  
 494  495          (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
 495  496  
 496  497          /*
 497  498           * If it's a full dataset name, figure out the pool name and
 498  499           * just use that.
 499  500           */
 500  501          cp = strpbrk(search.spa_name, "/@#");
 501  502          if (cp != NULL)
 502  503                  *cp = '\0';
 503  504  
 504  505          spa = avl_find(&spa_namespace_avl, &search, &where);
 505  506  
 506  507          return (spa);
 507  508  }
 508  509  
 509  510  /*
 510  511   * Fires when spa_sync has not completed within zfs_deadman_synctime_ms.
 511  512   * If the zfs_deadman_enabled flag is set then it inspects all vdev queues
 512  513   * looking for potentially hung I/Os.
 513  514   */
 514  515  void
 515  516  spa_deadman(void *arg)
 516  517  {
 517  518          spa_t *spa = arg;
 518  519  
 519  520          /*
 520  521           * Disable the deadman timer if the pool is suspended.
 521  522           */
 522  523          if (spa_suspended(spa)) {
 523  524                  VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
 524  525                  return;
 525  526          }
 526  527  
 527  528          zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
 528  529              (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
 529  530              ++spa->spa_deadman_calls);
 530  531          if (zfs_deadman_enabled)
 531  532                  vdev_deadman(spa->spa_root_vdev);
 532  533  }
 533  534  
 534  535  /*
 535  536   * Create an uninitialized spa_t with the given name.  Requires
 536  537   * spa_namespace_lock.  The caller must ensure that the spa_t doesn't already
 537  538   * exist by calling spa_lookup() first.
 538  539   */
 539  540  spa_t *
 540  541  spa_add(const char *name, nvlist_t *config, const char *altroot)
 541  542  {
 542  543          spa_t *spa;
 543  544          spa_config_dirent_t *dp;
  
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 544  545          cyc_handler_t hdlr;
 545  546          cyc_time_t when;
 546  547  
 547  548          ASSERT(MUTEX_HELD(&spa_namespace_lock));
 548  549  
 549  550          spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
 550  551  
 551  552          mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
 552  553          mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
 553  554          mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
      555 +        mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL);
 554  556          mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
 555  557          mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
 556  558          mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
 557  559          mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
 558  560          mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
 559  561          mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
 560  562          mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL);
 561  563  
 562  564          cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
      565 +        cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL);
 563  566          cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
 564  567          cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
 565  568          cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
 566  569  
 567  570          for (int t = 0; t < TXG_SIZE; t++)
 568  571                  bplist_create(&spa->spa_free_bplist[t]);
 569  572  
 570  573          (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
 571  574          spa->spa_state = POOL_STATE_UNINITIALIZED;
 572  575          spa->spa_freeze_txg = UINT64_MAX;
 573  576          spa->spa_final_txg = UINT64_MAX;
 574  577          spa->spa_load_max_txg = UINT64_MAX;
 575  578          spa->spa_proc = &p0;
 576  579          spa->spa_proc_state = SPA_PROC_NONE;
 577  580  
 578  581          hdlr.cyh_func = spa_deadman;
 579  582          hdlr.cyh_arg = spa;
 580  583          hdlr.cyh_level = CY_LOW_LEVEL;
 581  584  
 582  585          spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms);
 583  586  
 584  587          /*
 585  588           * This determines how often we need to check for hung I/Os after
 586  589           * the cyclic has already fired. Since checking for hung I/Os is
 587  590           * an expensive operation we don't want to check too frequently.
 588  591           * Instead wait for 5 seconds before checking again.
 589  592           */
 590  593          when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms);
 591  594          when.cyt_when = CY_INFINITY;
 592  595          mutex_enter(&cpu_lock);
 593  596          spa->spa_deadman_cycid = cyclic_add(&hdlr, &when);
 594  597          mutex_exit(&cpu_lock);
 595  598  
 596  599          refcount_create(&spa->spa_refcount);
 597  600          spa_config_lock_init(spa);
 598  601  
 599  602          avl_add(&spa_namespace_avl, spa);
 600  603  
 601  604          /*
 602  605           * Set the alternate root, if there is one.
 603  606           */
 604  607          if (altroot) {
 605  608                  spa->spa_root = spa_strdup(altroot);
 606  609                  spa_active_count++;
 607  610          }
 608  611  
 609  612          /*
 610  613           * Every pool starts with the default cachefile
 611  614           */
 612  615          list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
 613  616              offsetof(spa_config_dirent_t, scd_link));
 614  617  
 615  618          dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
 616  619          dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
 617  620          list_insert_head(&spa->spa_config_list, dp);
 618  621  
 619  622          VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
 620  623              KM_SLEEP) == 0);
 621  624  
 622  625          if (config != NULL) {
 623  626                  nvlist_t *features;
 624  627  
 625  628                  if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
 626  629                      &features) == 0) {
 627  630                          VERIFY(nvlist_dup(features, &spa->spa_label_features,
 628  631                              0) == 0);
 629  632                  }
 630  633  
 631  634                  VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
 632  635          }
 633  636  
 634  637          if (spa->spa_label_features == NULL) {
 635  638                  VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME,
 636  639                      KM_SLEEP) == 0);
 637  640          }
 638  641  
 639  642          spa->spa_iokstat = kstat_create("zfs", 0, name,
 640  643              "disk", KSTAT_TYPE_IO, 1, 0);
 641  644          if (spa->spa_iokstat) {
 642  645                  spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock;
 643  646                  kstat_install(spa->spa_iokstat);
 644  647          }
 645  648  
 646  649          spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0);
 647  650  
 648  651          /*
 649  652           * As a pool is being created, treat all features as disabled by
 650  653           * setting SPA_FEATURE_DISABLED for all entries in the feature
 651  654           * refcount cache.
 652  655           */
 653  656          for (int i = 0; i < SPA_FEATURES; i++) {
 654  657                  spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED;
 655  658          }
 656  659  
 657  660          return (spa);
 658  661  }
 659  662  
 660  663  /*
 661  664   * Removes a spa_t from the namespace, freeing up any memory used.  Requires
  
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 662  665   * spa_namespace_lock.  This is called only after the spa_t has been closed and
 663  666   * deactivated.
 664  667   */
 665  668  void
 666  669  spa_remove(spa_t *spa)
 667  670  {
 668  671          spa_config_dirent_t *dp;
 669  672  
 670  673          ASSERT(MUTEX_HELD(&spa_namespace_lock));
 671  674          ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
      675 +        ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0);
 672  676  
 673  677          nvlist_free(spa->spa_config_splitting);
 674  678  
 675  679          avl_remove(&spa_namespace_avl, spa);
 676  680          cv_broadcast(&spa_namespace_cv);
 677  681  
 678  682          if (spa->spa_root) {
 679  683                  spa_strfree(spa->spa_root);
 680  684                  spa_active_count--;
 681  685          }
 682  686  
 683  687          while ((dp = list_head(&spa->spa_config_list)) != NULL) {
 684  688                  list_remove(&spa->spa_config_list, dp);
 685  689                  if (dp->scd_path != NULL)
 686  690                          spa_strfree(dp->scd_path);
 687  691                  kmem_free(dp, sizeof (spa_config_dirent_t));
 688  692          }
 689  693  
 690  694          list_destroy(&spa->spa_config_list);
 691  695  
 692  696          nvlist_free(spa->spa_label_features);
 693  697          nvlist_free(spa->spa_load_info);
 694  698          spa_config_set(spa, NULL);
 695  699  
 696  700          mutex_enter(&cpu_lock);
 697  701          if (spa->spa_deadman_cycid != CYCLIC_NONE)
 698  702                  cyclic_remove(spa->spa_deadman_cycid);
 699  703          mutex_exit(&cpu_lock);
 700  704          spa->spa_deadman_cycid = CYCLIC_NONE;
 701  705  
 702  706          refcount_destroy(&spa->spa_refcount);
  
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 703  707  
 704  708          spa_config_lock_destroy(spa);
 705  709  
 706  710          kstat_delete(spa->spa_iokstat);
 707  711          spa->spa_iokstat = NULL;
 708  712  
 709  713          for (int t = 0; t < TXG_SIZE; t++)
 710  714                  bplist_destroy(&spa->spa_free_bplist[t]);
 711  715  
 712  716          cv_destroy(&spa->spa_async_cv);
      717 +        cv_destroy(&spa->spa_evicting_os_cv);
 713  718          cv_destroy(&spa->spa_proc_cv);
 714  719          cv_destroy(&spa->spa_scrub_io_cv);
 715  720          cv_destroy(&spa->spa_suspend_cv);
 716  721  
 717  722          mutex_destroy(&spa->spa_async_lock);
 718  723          mutex_destroy(&spa->spa_errlist_lock);
 719  724          mutex_destroy(&spa->spa_errlog_lock);
      725 +        mutex_destroy(&spa->spa_evicting_os_lock);
 720  726          mutex_destroy(&spa->spa_history_lock);
 721  727          mutex_destroy(&spa->spa_proc_lock);
 722  728          mutex_destroy(&spa->spa_props_lock);
 723  729          mutex_destroy(&spa->spa_scrub_lock);
 724  730          mutex_destroy(&spa->spa_suspend_lock);
 725  731          mutex_destroy(&spa->spa_vdev_top_lock);
 726  732          mutex_destroy(&spa->spa_iokstat_lock);
 727  733  
 728  734          kmem_free(spa, sizeof (spa_t));
 729  735  }
 730  736  
 731  737  /*
 732  738   * Given a pool, return the next pool in the namespace, or NULL if there is
 733  739   * none.  If 'prev' is NULL, return the first pool.
 734  740   */
 735  741  spa_t *
 736  742  spa_next(spa_t *prev)
 737  743  {
 738  744          ASSERT(MUTEX_HELD(&spa_namespace_lock));
 739  745  
 740  746          if (prev)
 741  747                  return (AVL_NEXT(&spa_namespace_avl, prev));
 742  748          else
 743  749                  return (avl_first(&spa_namespace_avl));
 744  750  }
 745  751  
 746  752  /*
 747  753   * ==========================================================================
 748  754   * SPA refcount functions
 749  755   * ==========================================================================
 750  756   */
 751  757  
 752  758  /*
 753  759   * Add a reference to the given spa_t.  Must have at least one reference, or
 754  760   * have the namespace lock held.
 755  761   */
 756  762  void
 757  763  spa_open_ref(spa_t *spa, void *tag)
 758  764  {
 759  765          ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
 760  766              MUTEX_HELD(&spa_namespace_lock));
 761  767          (void) refcount_add(&spa->spa_refcount, tag);
 762  768  }
 763  769  
 764  770  /*
 765  771   * Remove a reference to the given spa_t.  Must have at least one reference, or
 766  772   * have the namespace lock held.
  
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 767  773   */
 768  774  void
 769  775  spa_close(spa_t *spa, void *tag)
 770  776  {
 771  777          ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
 772  778              MUTEX_HELD(&spa_namespace_lock));
 773  779          (void) refcount_remove(&spa->spa_refcount, tag);
 774  780  }
 775  781  
 776  782  /*
      783 + * Remove a reference to the given spa_t held by a dsl dir that is
      784 + * being asynchronously released.  Async releases occur from a taskq
      785 + * performing eviction of dsl datasets and dirs.  The namespace lock
      786 + * isn't held and the hold by the object being evicted may contribute to
      787 + * spa_minref (e.g. dataset or directory released during pool export),
      788 + * so the asserts in spa_close() do not apply.
      789 + */
      790 +void
      791 +spa_async_close(spa_t *spa, void *tag)
      792 +{
      793 +        (void) refcount_remove(&spa->spa_refcount, tag);
      794 +}
      795 +
      796 +/*
 777  797   * Check to see if the spa refcount is zero.  Must be called with
 778  798   * spa_namespace_lock held.  We really compare against spa_minref, which is the
 779  799   * number of references acquired when opening a pool
 780  800   */
 781  801  boolean_t
 782  802  spa_refcount_zero(spa_t *spa)
 783  803  {
 784  804          ASSERT(MUTEX_HELD(&spa_namespace_lock));
 785  805  
 786  806          return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
 787  807  }
 788  808  
 789  809  /*
 790  810   * ==========================================================================
 791  811   * SPA spare and l2cache tracking
 792  812   * ==========================================================================
 793  813   */
 794  814  
 795  815  /*
 796  816   * Hot spares and cache devices are tracked using the same code below,
 797  817   * for 'auxiliary' devices.
 798  818   */
 799  819  
 800  820  typedef struct spa_aux {
 801  821          uint64_t        aux_guid;
 802  822          uint64_t        aux_pool;
 803  823          avl_node_t      aux_avl;
 804  824          int             aux_count;
 805  825  } spa_aux_t;
 806  826  
 807  827  static int
 808  828  spa_aux_compare(const void *a, const void *b)
 809  829  {
 810  830          const spa_aux_t *sa = a;
 811  831          const spa_aux_t *sb = b;
 812  832  
 813  833          if (sa->aux_guid < sb->aux_guid)
 814  834                  return (-1);
 815  835          else if (sa->aux_guid > sb->aux_guid)
 816  836                  return (1);
 817  837          else
 818  838                  return (0);
 819  839  }
 820  840  
 821  841  void
 822  842  spa_aux_add(vdev_t *vd, avl_tree_t *avl)
 823  843  {
 824  844          avl_index_t where;
 825  845          spa_aux_t search;
 826  846          spa_aux_t *aux;
 827  847  
 828  848          search.aux_guid = vd->vdev_guid;
 829  849          if ((aux = avl_find(avl, &search, &where)) != NULL) {
 830  850                  aux->aux_count++;
 831  851          } else {
 832  852                  aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
 833  853                  aux->aux_guid = vd->vdev_guid;
 834  854                  aux->aux_count = 1;
 835  855                  avl_insert(avl, aux, where);
 836  856          }
 837  857  }
 838  858  
 839  859  void
 840  860  spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
 841  861  {
 842  862          spa_aux_t search;
 843  863          spa_aux_t *aux;
 844  864          avl_index_t where;
 845  865  
 846  866          search.aux_guid = vd->vdev_guid;
 847  867          aux = avl_find(avl, &search, &where);
 848  868  
 849  869          ASSERT(aux != NULL);
 850  870  
 851  871          if (--aux->aux_count == 0) {
 852  872                  avl_remove(avl, aux);
 853  873                  kmem_free(aux, sizeof (spa_aux_t));
 854  874          } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
 855  875                  aux->aux_pool = 0ULL;
 856  876          }
 857  877  }
 858  878  
 859  879  boolean_t
 860  880  spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
 861  881  {
 862  882          spa_aux_t search, *found;
 863  883  
 864  884          search.aux_guid = guid;
 865  885          found = avl_find(avl, &search, NULL);
 866  886  
 867  887          if (pool) {
 868  888                  if (found)
 869  889                          *pool = found->aux_pool;
 870  890                  else
 871  891                          *pool = 0ULL;
 872  892          }
 873  893  
 874  894          if (refcnt) {
 875  895                  if (found)
 876  896                          *refcnt = found->aux_count;
 877  897                  else
 878  898                          *refcnt = 0;
 879  899          }
 880  900  
 881  901          return (found != NULL);
 882  902  }
 883  903  
 884  904  void
 885  905  spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
 886  906  {
 887  907          spa_aux_t search, *found;
 888  908          avl_index_t where;
 889  909  
 890  910          search.aux_guid = vd->vdev_guid;
 891  911          found = avl_find(avl, &search, &where);
 892  912          ASSERT(found != NULL);
 893  913          ASSERT(found->aux_pool == 0ULL);
 894  914  
 895  915          found->aux_pool = spa_guid(vd->vdev_spa);
 896  916  }
 897  917  
 898  918  /*
 899  919   * Spares are tracked globally due to the following constraints:
 900  920   *
 901  921   *      - A spare may be part of multiple pools.
 902  922   *      - A spare may be added to a pool even if it's actively in use within
 903  923   *        another pool.
 904  924   *      - A spare in use in any pool can only be the source of a replacement if
 905  925   *        the target is a spare in the same pool.
 906  926   *
 907  927   * We keep track of all spares on the system through the use of a reference
 908  928   * counted AVL tree.  When a vdev is added as a spare, or used as a replacement
 909  929   * spare, then we bump the reference count in the AVL tree.  In addition, we set
 910  930   * the 'vdev_isspare' member to indicate that the device is a spare (active or
 911  931   * inactive).  When a spare is made active (used to replace a device in the
 912  932   * pool), we also keep track of which pool its been made a part of.
 913  933   *
 914  934   * The 'spa_spare_lock' protects the AVL tree.  These functions are normally
 915  935   * called under the spa_namespace lock as part of vdev reconfiguration.  The
 916  936   * separate spare lock exists for the status query path, which does not need to
 917  937   * be completely consistent with respect to other vdev configuration changes.
 918  938   */
 919  939  
 920  940  static int
 921  941  spa_spare_compare(const void *a, const void *b)
 922  942  {
 923  943          return (spa_aux_compare(a, b));
 924  944  }
 925  945  
 926  946  void
 927  947  spa_spare_add(vdev_t *vd)
 928  948  {
 929  949          mutex_enter(&spa_spare_lock);
 930  950          ASSERT(!vd->vdev_isspare);
 931  951          spa_aux_add(vd, &spa_spare_avl);
 932  952          vd->vdev_isspare = B_TRUE;
 933  953          mutex_exit(&spa_spare_lock);
 934  954  }
 935  955  
 936  956  void
 937  957  spa_spare_remove(vdev_t *vd)
 938  958  {
 939  959          mutex_enter(&spa_spare_lock);
 940  960          ASSERT(vd->vdev_isspare);
 941  961          spa_aux_remove(vd, &spa_spare_avl);
 942  962          vd->vdev_isspare = B_FALSE;
 943  963          mutex_exit(&spa_spare_lock);
 944  964  }
 945  965  
 946  966  boolean_t
 947  967  spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
 948  968  {
 949  969          boolean_t found;
 950  970  
 951  971          mutex_enter(&spa_spare_lock);
 952  972          found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
 953  973          mutex_exit(&spa_spare_lock);
 954  974  
 955  975          return (found);
 956  976  }
 957  977  
 958  978  void
 959  979  spa_spare_activate(vdev_t *vd)
 960  980  {
 961  981          mutex_enter(&spa_spare_lock);
 962  982          ASSERT(vd->vdev_isspare);
 963  983          spa_aux_activate(vd, &spa_spare_avl);
 964  984          mutex_exit(&spa_spare_lock);
 965  985  }
 966  986  
 967  987  /*
 968  988   * Level 2 ARC devices are tracked globally for the same reasons as spares.
 969  989   * Cache devices currently only support one pool per cache device, and so
 970  990   * for these devices the aux reference count is currently unused beyond 1.
 971  991   */
 972  992  
 973  993  static int
 974  994  spa_l2cache_compare(const void *a, const void *b)
 975  995  {
 976  996          return (spa_aux_compare(a, b));
 977  997  }
 978  998  
 979  999  void
 980 1000  spa_l2cache_add(vdev_t *vd)
 981 1001  {
 982 1002          mutex_enter(&spa_l2cache_lock);
 983 1003          ASSERT(!vd->vdev_isl2cache);
 984 1004          spa_aux_add(vd, &spa_l2cache_avl);
 985 1005          vd->vdev_isl2cache = B_TRUE;
 986 1006          mutex_exit(&spa_l2cache_lock);
 987 1007  }
 988 1008  
 989 1009  void
 990 1010  spa_l2cache_remove(vdev_t *vd)
 991 1011  {
 992 1012          mutex_enter(&spa_l2cache_lock);
 993 1013          ASSERT(vd->vdev_isl2cache);
 994 1014          spa_aux_remove(vd, &spa_l2cache_avl);
 995 1015          vd->vdev_isl2cache = B_FALSE;
 996 1016          mutex_exit(&spa_l2cache_lock);
 997 1017  }
 998 1018  
 999 1019  boolean_t
1000 1020  spa_l2cache_exists(uint64_t guid, uint64_t *pool)
1001 1021  {
1002 1022          boolean_t found;
1003 1023  
1004 1024          mutex_enter(&spa_l2cache_lock);
1005 1025          found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
1006 1026          mutex_exit(&spa_l2cache_lock);
1007 1027  
1008 1028          return (found);
1009 1029  }
1010 1030  
1011 1031  void
1012 1032  spa_l2cache_activate(vdev_t *vd)
1013 1033  {
1014 1034          mutex_enter(&spa_l2cache_lock);
1015 1035          ASSERT(vd->vdev_isl2cache);
1016 1036          spa_aux_activate(vd, &spa_l2cache_avl);
1017 1037          mutex_exit(&spa_l2cache_lock);
1018 1038  }
1019 1039  
1020 1040  /*
1021 1041   * ==========================================================================
1022 1042   * SPA vdev locking
1023 1043   * ==========================================================================
1024 1044   */
1025 1045  
1026 1046  /*
1027 1047   * Lock the given spa_t for the purpose of adding or removing a vdev.
1028 1048   * Grabs the global spa_namespace_lock plus the spa config lock for writing.
1029 1049   * It returns the next transaction group for the spa_t.
1030 1050   */
1031 1051  uint64_t
1032 1052  spa_vdev_enter(spa_t *spa)
1033 1053  {
1034 1054          mutex_enter(&spa->spa_vdev_top_lock);
1035 1055          mutex_enter(&spa_namespace_lock);
1036 1056          return (spa_vdev_config_enter(spa));
1037 1057  }
1038 1058  
1039 1059  /*
1040 1060   * Internal implementation for spa_vdev_enter().  Used when a vdev
1041 1061   * operation requires multiple syncs (i.e. removing a device) while
1042 1062   * keeping the spa_namespace_lock held.
1043 1063   */
1044 1064  uint64_t
1045 1065  spa_vdev_config_enter(spa_t *spa)
1046 1066  {
1047 1067          ASSERT(MUTEX_HELD(&spa_namespace_lock));
1048 1068  
1049 1069          spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1050 1070  
1051 1071          return (spa_last_synced_txg(spa) + 1);
1052 1072  }
1053 1073  
1054 1074  /*
1055 1075   * Used in combination with spa_vdev_config_enter() to allow the syncing
1056 1076   * of multiple transactions without releasing the spa_namespace_lock.
1057 1077   */
1058 1078  void
1059 1079  spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
1060 1080  {
1061 1081          ASSERT(MUTEX_HELD(&spa_namespace_lock));
1062 1082  
1063 1083          int config_changed = B_FALSE;
1064 1084  
1065 1085          ASSERT(txg > spa_last_synced_txg(spa));
1066 1086  
1067 1087          spa->spa_pending_vdev = NULL;
1068 1088  
1069 1089          /*
1070 1090           * Reassess the DTLs.
1071 1091           */
1072 1092          vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
1073 1093  
1074 1094          if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
1075 1095                  config_changed = B_TRUE;
1076 1096                  spa->spa_config_generation++;
1077 1097          }
1078 1098  
1079 1099          /*
1080 1100           * Verify the metaslab classes.
1081 1101           */
1082 1102          ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
1083 1103          ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
1084 1104  
1085 1105          spa_config_exit(spa, SCL_ALL, spa);
1086 1106  
1087 1107          /*
1088 1108           * Panic the system if the specified tag requires it.  This
1089 1109           * is useful for ensuring that configurations are updated
1090 1110           * transactionally.
1091 1111           */
1092 1112          if (zio_injection_enabled)
1093 1113                  zio_handle_panic_injection(spa, tag, 0);
1094 1114  
1095 1115          /*
1096 1116           * Note: this txg_wait_synced() is important because it ensures
1097 1117           * that there won't be more than one config change per txg.
1098 1118           * This allows us to use the txg as the generation number.
1099 1119           */
1100 1120          if (error == 0)
1101 1121                  txg_wait_synced(spa->spa_dsl_pool, txg);
1102 1122  
1103 1123          if (vd != NULL) {
1104 1124                  ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
1105 1125                  spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1106 1126                  vdev_free(vd);
1107 1127                  spa_config_exit(spa, SCL_ALL, spa);
1108 1128          }
1109 1129  
1110 1130          /*
1111 1131           * If the config changed, update the config cache.
1112 1132           */
1113 1133          if (config_changed)
1114 1134                  spa_config_sync(spa, B_FALSE, B_TRUE);
1115 1135  }
1116 1136  
1117 1137  /*
1118 1138   * Unlock the spa_t after adding or removing a vdev.  Besides undoing the
1119 1139   * locking of spa_vdev_enter(), we also want make sure the transactions have
1120 1140   * synced to disk, and then update the global configuration cache with the new
1121 1141   * information.
1122 1142   */
1123 1143  int
1124 1144  spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
1125 1145  {
1126 1146          spa_vdev_config_exit(spa, vd, txg, error, FTAG);
1127 1147          mutex_exit(&spa_namespace_lock);
1128 1148          mutex_exit(&spa->spa_vdev_top_lock);
1129 1149  
1130 1150          return (error);
1131 1151  }
1132 1152  
1133 1153  /*
1134 1154   * Lock the given spa_t for the purpose of changing vdev state.
1135 1155   */
1136 1156  void
1137 1157  spa_vdev_state_enter(spa_t *spa, int oplocks)
1138 1158  {
1139 1159          int locks = SCL_STATE_ALL | oplocks;
1140 1160  
1141 1161          /*
1142 1162           * Root pools may need to read of the underlying devfs filesystem
1143 1163           * when opening up a vdev.  Unfortunately if we're holding the
1144 1164           * SCL_ZIO lock it will result in a deadlock when we try to issue
1145 1165           * the read from the root filesystem.  Instead we "prefetch"
1146 1166           * the associated vnodes that we need prior to opening the
1147 1167           * underlying devices and cache them so that we can prevent
1148 1168           * any I/O when we are doing the actual open.
1149 1169           */
1150 1170          if (spa_is_root(spa)) {
1151 1171                  int low = locks & ~(SCL_ZIO - 1);
1152 1172                  int high = locks & ~low;
1153 1173  
1154 1174                  spa_config_enter(spa, high, spa, RW_WRITER);
1155 1175                  vdev_hold(spa->spa_root_vdev);
1156 1176                  spa_config_enter(spa, low, spa, RW_WRITER);
1157 1177          } else {
1158 1178                  spa_config_enter(spa, locks, spa, RW_WRITER);
1159 1179          }
1160 1180          spa->spa_vdev_locks = locks;
1161 1181  }
1162 1182  
1163 1183  int
1164 1184  spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
1165 1185  {
1166 1186          boolean_t config_changed = B_FALSE;
1167 1187  
1168 1188          if (vd != NULL || error == 0)
1169 1189                  vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
1170 1190                      0, 0, B_FALSE);
1171 1191  
1172 1192          if (vd != NULL) {
1173 1193                  vdev_state_dirty(vd->vdev_top);
1174 1194                  config_changed = B_TRUE;
1175 1195                  spa->spa_config_generation++;
1176 1196          }
1177 1197  
1178 1198          if (spa_is_root(spa))
1179 1199                  vdev_rele(spa->spa_root_vdev);
1180 1200  
1181 1201          ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1182 1202          spa_config_exit(spa, spa->spa_vdev_locks, spa);
1183 1203  
1184 1204          /*
1185 1205           * If anything changed, wait for it to sync.  This ensures that,
1186 1206           * from the system administrator's perspective, zpool(1M) commands
1187 1207           * are synchronous.  This is important for things like zpool offline:
1188 1208           * when the command completes, you expect no further I/O from ZFS.
1189 1209           */
1190 1210          if (vd != NULL)
1191 1211                  txg_wait_synced(spa->spa_dsl_pool, 0);
1192 1212  
1193 1213          /*
1194 1214           * If the config changed, update the config cache.
1195 1215           */
1196 1216          if (config_changed) {
1197 1217                  mutex_enter(&spa_namespace_lock);
1198 1218                  spa_config_sync(spa, B_FALSE, B_TRUE);
1199 1219                  mutex_exit(&spa_namespace_lock);
1200 1220          }
1201 1221  
1202 1222          return (error);
1203 1223  }
1204 1224  
1205 1225  /*
1206 1226   * ==========================================================================
1207 1227   * Miscellaneous functions
1208 1228   * ==========================================================================
1209 1229   */
1210 1230  
1211 1231  void
1212 1232  spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx)
1213 1233  {
1214 1234          if (!nvlist_exists(spa->spa_label_features, feature)) {
1215 1235                  fnvlist_add_boolean(spa->spa_label_features, feature);
1216 1236                  /*
1217 1237                   * When we are creating the pool (tx_txg==TXG_INITIAL), we can't
1218 1238                   * dirty the vdev config because lock SCL_CONFIG is not held.
1219 1239                   * Thankfully, in this case we don't need to dirty the config
1220 1240                   * because it will be written out anyway when we finish
1221 1241                   * creating the pool.
1222 1242                   */
1223 1243                  if (tx->tx_txg != TXG_INITIAL)
1224 1244                          vdev_config_dirty(spa->spa_root_vdev);
1225 1245          }
1226 1246  }
1227 1247  
1228 1248  void
1229 1249  spa_deactivate_mos_feature(spa_t *spa, const char *feature)
1230 1250  {
1231 1251          if (nvlist_remove_all(spa->spa_label_features, feature) == 0)
1232 1252                  vdev_config_dirty(spa->spa_root_vdev);
1233 1253  }
1234 1254  
1235 1255  /*
1236 1256   * Rename a spa_t.
1237 1257   */
1238 1258  int
1239 1259  spa_rename(const char *name, const char *newname)
1240 1260  {
1241 1261          spa_t *spa;
1242 1262          int err;
1243 1263  
1244 1264          /*
1245 1265           * Lookup the spa_t and grab the config lock for writing.  We need to
1246 1266           * actually open the pool so that we can sync out the necessary labels.
1247 1267           * It's OK to call spa_open() with the namespace lock held because we
1248 1268           * allow recursive calls for other reasons.
1249 1269           */
1250 1270          mutex_enter(&spa_namespace_lock);
1251 1271          if ((err = spa_open(name, &spa, FTAG)) != 0) {
1252 1272                  mutex_exit(&spa_namespace_lock);
1253 1273                  return (err);
1254 1274          }
1255 1275  
1256 1276          spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1257 1277  
1258 1278          avl_remove(&spa_namespace_avl, spa);
1259 1279          (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1260 1280          avl_add(&spa_namespace_avl, spa);
1261 1281  
1262 1282          /*
1263 1283           * Sync all labels to disk with the new names by marking the root vdev
1264 1284           * dirty and waiting for it to sync.  It will pick up the new pool name
1265 1285           * during the sync.
1266 1286           */
1267 1287          vdev_config_dirty(spa->spa_root_vdev);
1268 1288  
1269 1289          spa_config_exit(spa, SCL_ALL, FTAG);
1270 1290  
1271 1291          txg_wait_synced(spa->spa_dsl_pool, 0);
1272 1292  
1273 1293          /*
1274 1294           * Sync the updated config cache.
1275 1295           */
1276 1296          spa_config_sync(spa, B_FALSE, B_TRUE);
1277 1297  
1278 1298          spa_close(spa, FTAG);
1279 1299  
1280 1300          mutex_exit(&spa_namespace_lock);
1281 1301  
1282 1302          return (0);
1283 1303  }
1284 1304  
1285 1305  /*
1286 1306   * Return the spa_t associated with given pool_guid, if it exists.  If
1287 1307   * device_guid is non-zero, determine whether the pool exists *and* contains
1288 1308   * a device with the specified device_guid.
1289 1309   */
1290 1310  spa_t *
1291 1311  spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1292 1312  {
1293 1313          spa_t *spa;
1294 1314          avl_tree_t *t = &spa_namespace_avl;
1295 1315  
1296 1316          ASSERT(MUTEX_HELD(&spa_namespace_lock));
1297 1317  
1298 1318          for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1299 1319                  if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1300 1320                          continue;
1301 1321                  if (spa->spa_root_vdev == NULL)
1302 1322                          continue;
1303 1323                  if (spa_guid(spa) == pool_guid) {
1304 1324                          if (device_guid == 0)
1305 1325                                  break;
1306 1326  
1307 1327                          if (vdev_lookup_by_guid(spa->spa_root_vdev,
1308 1328                              device_guid) != NULL)
1309 1329                                  break;
1310 1330  
1311 1331                          /*
1312 1332                           * Check any devices we may be in the process of adding.
1313 1333                           */
1314 1334                          if (spa->spa_pending_vdev) {
1315 1335                                  if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1316 1336                                      device_guid) != NULL)
1317 1337                                          break;
1318 1338                          }
1319 1339                  }
1320 1340          }
1321 1341  
1322 1342          return (spa);
1323 1343  }
1324 1344  
1325 1345  /*
1326 1346   * Determine whether a pool with the given pool_guid exists.
1327 1347   */
1328 1348  boolean_t
1329 1349  spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1330 1350  {
1331 1351          return (spa_by_guid(pool_guid, device_guid) != NULL);
1332 1352  }
1333 1353  
1334 1354  char *
1335 1355  spa_strdup(const char *s)
1336 1356  {
1337 1357          size_t len;
1338 1358          char *new;
1339 1359  
1340 1360          len = strlen(s);
1341 1361          new = kmem_alloc(len + 1, KM_SLEEP);
1342 1362          bcopy(s, new, len);
1343 1363          new[len] = '\0';
1344 1364  
1345 1365          return (new);
1346 1366  }
1347 1367  
1348 1368  void
1349 1369  spa_strfree(char *s)
1350 1370  {
1351 1371          kmem_free(s, strlen(s) + 1);
1352 1372  }
1353 1373  
1354 1374  uint64_t
1355 1375  spa_get_random(uint64_t range)
1356 1376  {
1357 1377          uint64_t r;
1358 1378  
1359 1379          ASSERT(range != 0);
1360 1380  
1361 1381          (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1362 1382  
1363 1383          return (r % range);
1364 1384  }
1365 1385  
1366 1386  uint64_t
1367 1387  spa_generate_guid(spa_t *spa)
1368 1388  {
1369 1389          uint64_t guid = spa_get_random(-1ULL);
1370 1390  
1371 1391          if (spa != NULL) {
1372 1392                  while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1373 1393                          guid = spa_get_random(-1ULL);
1374 1394          } else {
1375 1395                  while (guid == 0 || spa_guid_exists(guid, 0))
1376 1396                          guid = spa_get_random(-1ULL);
1377 1397          }
1378 1398  
1379 1399          return (guid);
1380 1400  }
1381 1401  
1382 1402  void
1383 1403  snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp)
1384 1404  {
1385 1405          char type[256];
1386 1406          char *checksum = NULL;
1387 1407          char *compress = NULL;
1388 1408  
1389 1409          if (bp != NULL) {
1390 1410                  if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) {
1391 1411                          dmu_object_byteswap_t bswap =
1392 1412                              DMU_OT_BYTESWAP(BP_GET_TYPE(bp));
1393 1413                          (void) snprintf(type, sizeof (type), "bswap %s %s",
1394 1414                              DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ?
1395 1415                              "metadata" : "data",
1396 1416                              dmu_ot_byteswap[bswap].ob_name);
1397 1417                  } else {
1398 1418                          (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name,
1399 1419                              sizeof (type));
1400 1420                  }
1401 1421                  if (!BP_IS_EMBEDDED(bp)) {
1402 1422                          checksum =
1403 1423                              zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1404 1424                  }
1405 1425                  compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1406 1426          }
1407 1427  
1408 1428          SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum,
1409 1429              compress);
1410 1430  }
1411 1431  
1412 1432  void
1413 1433  spa_freeze(spa_t *spa)
1414 1434  {
1415 1435          uint64_t freeze_txg = 0;
1416 1436  
1417 1437          spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1418 1438          if (spa->spa_freeze_txg == UINT64_MAX) {
1419 1439                  freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1420 1440                  spa->spa_freeze_txg = freeze_txg;
1421 1441          }
1422 1442          spa_config_exit(spa, SCL_ALL, FTAG);
1423 1443          if (freeze_txg != 0)
1424 1444                  txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1425 1445  }
1426 1446  
1427 1447  void
1428 1448  zfs_panic_recover(const char *fmt, ...)
1429 1449  {
1430 1450          va_list adx;
1431 1451  
1432 1452          va_start(adx, fmt);
1433 1453          vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1434 1454          va_end(adx);
1435 1455  }
1436 1456  
1437 1457  /*
1438 1458   * This is a stripped-down version of strtoull, suitable only for converting
1439 1459   * lowercase hexadecimal numbers that don't overflow.
1440 1460   */
1441 1461  uint64_t
1442 1462  strtonum(const char *str, char **nptr)
1443 1463  {
1444 1464          uint64_t val = 0;
1445 1465          char c;
1446 1466          int digit;
1447 1467  
1448 1468          while ((c = *str) != '\0') {
1449 1469                  if (c >= '0' && c <= '9')
1450 1470                          digit = c - '0';
1451 1471                  else if (c >= 'a' && c <= 'f')
1452 1472                          digit = 10 + c - 'a';
1453 1473                  else
1454 1474                          break;
1455 1475  
1456 1476                  val *= 16;
1457 1477                  val += digit;
1458 1478  
1459 1479                  str++;
1460 1480          }
1461 1481  
1462 1482          if (nptr)
1463 1483                  *nptr = (char *)str;
1464 1484  
1465 1485          return (val);
1466 1486  }
1467 1487  
1468 1488  /*
1469 1489   * ==========================================================================
1470 1490   * Accessor functions
1471 1491   * ==========================================================================
1472 1492   */
1473 1493  
1474 1494  boolean_t
1475 1495  spa_shutting_down(spa_t *spa)
1476 1496  {
1477 1497          return (spa->spa_async_suspended);
1478 1498  }
1479 1499  
1480 1500  dsl_pool_t *
1481 1501  spa_get_dsl(spa_t *spa)
1482 1502  {
1483 1503          return (spa->spa_dsl_pool);
1484 1504  }
1485 1505  
1486 1506  boolean_t
1487 1507  spa_is_initializing(spa_t *spa)
1488 1508  {
1489 1509          return (spa->spa_is_initializing);
1490 1510  }
1491 1511  
1492 1512  blkptr_t *
1493 1513  spa_get_rootblkptr(spa_t *spa)
1494 1514  {
1495 1515          return (&spa->spa_ubsync.ub_rootbp);
1496 1516  }
1497 1517  
1498 1518  void
1499 1519  spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1500 1520  {
1501 1521          spa->spa_uberblock.ub_rootbp = *bp;
1502 1522  }
1503 1523  
1504 1524  void
1505 1525  spa_altroot(spa_t *spa, char *buf, size_t buflen)
1506 1526  {
1507 1527          if (spa->spa_root == NULL)
1508 1528                  buf[0] = '\0';
1509 1529          else
1510 1530                  (void) strncpy(buf, spa->spa_root, buflen);
1511 1531  }
1512 1532  
1513 1533  int
1514 1534  spa_sync_pass(spa_t *spa)
1515 1535  {
1516 1536          return (spa->spa_sync_pass);
1517 1537  }
1518 1538  
1519 1539  char *
1520 1540  spa_name(spa_t *spa)
1521 1541  {
1522 1542          return (spa->spa_name);
1523 1543  }
1524 1544  
1525 1545  uint64_t
1526 1546  spa_guid(spa_t *spa)
1527 1547  {
1528 1548          dsl_pool_t *dp = spa_get_dsl(spa);
1529 1549          uint64_t guid;
1530 1550  
1531 1551          /*
1532 1552           * If we fail to parse the config during spa_load(), we can go through
1533 1553           * the error path (which posts an ereport) and end up here with no root
1534 1554           * vdev.  We stash the original pool guid in 'spa_config_guid' to handle
1535 1555           * this case.
1536 1556           */
1537 1557          if (spa->spa_root_vdev == NULL)
1538 1558                  return (spa->spa_config_guid);
1539 1559  
1540 1560          guid = spa->spa_last_synced_guid != 0 ?
1541 1561              spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid;
1542 1562  
1543 1563          /*
1544 1564           * Return the most recently synced out guid unless we're
1545 1565           * in syncing context.
1546 1566           */
1547 1567          if (dp && dsl_pool_sync_context(dp))
1548 1568                  return (spa->spa_root_vdev->vdev_guid);
1549 1569          else
1550 1570                  return (guid);
1551 1571  }
1552 1572  
1553 1573  uint64_t
1554 1574  spa_load_guid(spa_t *spa)
1555 1575  {
1556 1576          /*
1557 1577           * This is a GUID that exists solely as a reference for the
1558 1578           * purposes of the arc.  It is generated at load time, and
1559 1579           * is never written to persistent storage.
1560 1580           */
1561 1581          return (spa->spa_load_guid);
1562 1582  }
1563 1583  
1564 1584  uint64_t
1565 1585  spa_last_synced_txg(spa_t *spa)
1566 1586  {
1567 1587          return (spa->spa_ubsync.ub_txg);
1568 1588  }
1569 1589  
1570 1590  uint64_t
1571 1591  spa_first_txg(spa_t *spa)
1572 1592  {
1573 1593          return (spa->spa_first_txg);
1574 1594  }
1575 1595  
1576 1596  uint64_t
1577 1597  spa_syncing_txg(spa_t *spa)
1578 1598  {
1579 1599          return (spa->spa_syncing_txg);
1580 1600  }
1581 1601  
1582 1602  pool_state_t
1583 1603  spa_state(spa_t *spa)
1584 1604  {
1585 1605          return (spa->spa_state);
1586 1606  }
1587 1607  
1588 1608  spa_load_state_t
1589 1609  spa_load_state(spa_t *spa)
1590 1610  {
1591 1611          return (spa->spa_load_state);
1592 1612  }
1593 1613  
1594 1614  uint64_t
1595 1615  spa_freeze_txg(spa_t *spa)
1596 1616  {
1597 1617          return (spa->spa_freeze_txg);
1598 1618  }
1599 1619  
1600 1620  /* ARGSUSED */
1601 1621  uint64_t
1602 1622  spa_get_asize(spa_t *spa, uint64_t lsize)
1603 1623  {
1604 1624          return (lsize * spa_asize_inflation);
1605 1625  }
1606 1626  
1607 1627  /*
1608 1628   * Return the amount of slop space in bytes.  It is 1/32 of the pool (3.2%),
1609 1629   * or at least 32MB.
1610 1630   *
1611 1631   * See the comment above spa_slop_shift for details.
1612 1632   */
1613 1633  uint64_t
1614 1634  spa_get_slop_space(spa_t *spa) {
1615 1635          uint64_t space = spa_get_dspace(spa);
1616 1636          return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1));
1617 1637  }
1618 1638  
1619 1639  uint64_t
1620 1640  spa_get_dspace(spa_t *spa)
1621 1641  {
1622 1642          return (spa->spa_dspace);
1623 1643  }
1624 1644  
1625 1645  void
1626 1646  spa_update_dspace(spa_t *spa)
1627 1647  {
1628 1648          spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1629 1649              ddt_get_dedup_dspace(spa);
1630 1650  }
1631 1651  
1632 1652  /*
1633 1653   * Return the failure mode that has been set to this pool. The default
1634 1654   * behavior will be to block all I/Os when a complete failure occurs.
1635 1655   */
1636 1656  uint8_t
1637 1657  spa_get_failmode(spa_t *spa)
1638 1658  {
1639 1659          return (spa->spa_failmode);
1640 1660  }
1641 1661  
1642 1662  boolean_t
1643 1663  spa_suspended(spa_t *spa)
1644 1664  {
1645 1665          return (spa->spa_suspended);
1646 1666  }
1647 1667  
1648 1668  uint64_t
1649 1669  spa_version(spa_t *spa)
1650 1670  {
1651 1671          return (spa->spa_ubsync.ub_version);
1652 1672  }
1653 1673  
1654 1674  boolean_t
1655 1675  spa_deflate(spa_t *spa)
1656 1676  {
1657 1677          return (spa->spa_deflate);
1658 1678  }
1659 1679  
1660 1680  metaslab_class_t *
1661 1681  spa_normal_class(spa_t *spa)
  
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1662 1682  {
1663 1683          return (spa->spa_normal_class);
1664 1684  }
1665 1685  
1666 1686  metaslab_class_t *
1667 1687  spa_log_class(spa_t *spa)
1668 1688  {
1669 1689          return (spa->spa_log_class);
1670 1690  }
1671 1691  
     1692 +void
     1693 +spa_evicting_os_register(spa_t *spa, objset_t *os)
     1694 +{
     1695 +        mutex_enter(&spa->spa_evicting_os_lock);
     1696 +        list_insert_head(&spa->spa_evicting_os_list, os);
     1697 +        mutex_exit(&spa->spa_evicting_os_lock);
     1698 +}
     1699 +
     1700 +void
     1701 +spa_evicting_os_deregister(spa_t *spa, objset_t *os)
     1702 +{
     1703 +        mutex_enter(&spa->spa_evicting_os_lock);
     1704 +        list_remove(&spa->spa_evicting_os_list, os);
     1705 +        cv_broadcast(&spa->spa_evicting_os_cv);
     1706 +        mutex_exit(&spa->spa_evicting_os_lock);
     1707 +}
     1708 +
     1709 +void
     1710 +spa_evicting_os_wait(spa_t *spa)
     1711 +{
     1712 +        mutex_enter(&spa->spa_evicting_os_lock);
     1713 +        while (!list_is_empty(&spa->spa_evicting_os_list))
     1714 +                cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock);
     1715 +        mutex_exit(&spa->spa_evicting_os_lock);
     1716 +
     1717 +        dmu_buf_user_evict_wait();
     1718 +}
     1719 +
1672 1720  int
1673 1721  spa_max_replication(spa_t *spa)
1674 1722  {
1675 1723          /*
1676 1724           * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1677 1725           * handle BPs with more than one DVA allocated.  Set our max
1678 1726           * replication level accordingly.
1679 1727           */
1680 1728          if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1681 1729                  return (1);
1682 1730          return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1683 1731  }
1684 1732  
1685 1733  int
1686 1734  spa_prev_software_version(spa_t *spa)
1687 1735  {
1688 1736          return (spa->spa_prev_software_version);
1689 1737  }
1690 1738  
1691 1739  uint64_t
1692 1740  spa_deadman_synctime(spa_t *spa)
1693 1741  {
1694 1742          return (spa->spa_deadman_synctime);
1695 1743  }
1696 1744  
1697 1745  uint64_t
1698 1746  dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1699 1747  {
1700 1748          uint64_t asize = DVA_GET_ASIZE(dva);
1701 1749          uint64_t dsize = asize;
1702 1750  
1703 1751          ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1704 1752  
1705 1753          if (asize != 0 && spa->spa_deflate) {
1706 1754                  vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1707 1755                  dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1708 1756          }
1709 1757  
1710 1758          return (dsize);
1711 1759  }
1712 1760  
1713 1761  uint64_t
1714 1762  bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1715 1763  {
1716 1764          uint64_t dsize = 0;
1717 1765  
1718 1766          for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1719 1767                  dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1720 1768  
1721 1769          return (dsize);
1722 1770  }
1723 1771  
1724 1772  uint64_t
1725 1773  bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1726 1774  {
1727 1775          uint64_t dsize = 0;
1728 1776  
1729 1777          spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1730 1778  
1731 1779          for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1732 1780                  dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1733 1781  
1734 1782          spa_config_exit(spa, SCL_VDEV, FTAG);
1735 1783  
1736 1784          return (dsize);
1737 1785  }
1738 1786  
1739 1787  /*
1740 1788   * ==========================================================================
1741 1789   * Initialization and Termination
1742 1790   * ==========================================================================
1743 1791   */
1744 1792  
1745 1793  static int
1746 1794  spa_name_compare(const void *a1, const void *a2)
1747 1795  {
1748 1796          const spa_t *s1 = a1;
1749 1797          const spa_t *s2 = a2;
1750 1798          int s;
1751 1799  
1752 1800          s = strcmp(s1->spa_name, s2->spa_name);
1753 1801          if (s > 0)
1754 1802                  return (1);
1755 1803          if (s < 0)
1756 1804                  return (-1);
1757 1805          return (0);
1758 1806  }
1759 1807  
1760 1808  int
1761 1809  spa_busy(void)
1762 1810  {
1763 1811          return (spa_active_count);
1764 1812  }
1765 1813  
1766 1814  void
1767 1815  spa_boot_init()
1768 1816  {
1769 1817          spa_config_load();
1770 1818  }
1771 1819  
1772 1820  void
1773 1821  spa_init(int mode)
1774 1822  {
1775 1823          mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1776 1824          mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1777 1825          mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1778 1826          cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1779 1827  
1780 1828          avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1781 1829              offsetof(spa_t, spa_avl));
1782 1830  
1783 1831          avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1784 1832              offsetof(spa_aux_t, aux_avl));
1785 1833  
1786 1834          avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1787 1835              offsetof(spa_aux_t, aux_avl));
1788 1836  
1789 1837          spa_mode_global = mode;
1790 1838  
1791 1839  #ifdef _KERNEL
1792 1840          spa_arch_init();
1793 1841  #else
1794 1842          if (spa_mode_global != FREAD && dprintf_find_string("watch")) {
1795 1843                  arc_procfd = open("/proc/self/ctl", O_WRONLY);
1796 1844                  if (arc_procfd == -1) {
1797 1845                          perror("could not enable watchpoints: "
1798 1846                              "opening /proc/self/ctl failed: ");
1799 1847                  } else {
1800 1848                          arc_watch = B_TRUE;
1801 1849                  }
1802 1850          }
1803 1851  #endif
1804 1852  
1805 1853          refcount_init();
1806 1854          unique_init();
1807 1855          range_tree_init();
1808 1856          zio_init();
1809 1857          dmu_init();
1810 1858          zil_init();
1811 1859          vdev_cache_stat_init();
1812 1860          zfs_prop_init();
1813 1861          zpool_prop_init();
1814 1862          zpool_feature_init();
1815 1863          spa_config_load();
1816 1864          l2arc_start();
1817 1865  }
1818 1866  
1819 1867  void
1820 1868  spa_fini(void)
1821 1869  {
1822 1870          l2arc_stop();
1823 1871  
1824 1872          spa_evict_all();
1825 1873  
1826 1874          vdev_cache_stat_fini();
1827 1875          zil_fini();
1828 1876          dmu_fini();
1829 1877          zio_fini();
1830 1878          range_tree_fini();
1831 1879          unique_fini();
1832 1880          refcount_fini();
1833 1881  
1834 1882          avl_destroy(&spa_namespace_avl);
1835 1883          avl_destroy(&spa_spare_avl);
1836 1884          avl_destroy(&spa_l2cache_avl);
1837 1885  
1838 1886          cv_destroy(&spa_namespace_cv);
1839 1887          mutex_destroy(&spa_namespace_lock);
1840 1888          mutex_destroy(&spa_spare_lock);
1841 1889          mutex_destroy(&spa_l2cache_lock);
1842 1890  }
1843 1891  
1844 1892  /*
1845 1893   * Return whether this pool has slogs. No locking needed.
1846 1894   * It's not a problem if the wrong answer is returned as it's only for
1847 1895   * performance and not correctness
1848 1896   */
1849 1897  boolean_t
1850 1898  spa_has_slogs(spa_t *spa)
1851 1899  {
1852 1900          return (spa->spa_log_class->mc_rotor != NULL);
1853 1901  }
1854 1902  
1855 1903  spa_log_state_t
1856 1904  spa_get_log_state(spa_t *spa)
1857 1905  {
1858 1906          return (spa->spa_log_state);
1859 1907  }
1860 1908  
1861 1909  void
1862 1910  spa_set_log_state(spa_t *spa, spa_log_state_t state)
1863 1911  {
1864 1912          spa->spa_log_state = state;
1865 1913  }
1866 1914  
1867 1915  boolean_t
1868 1916  spa_is_root(spa_t *spa)
1869 1917  {
1870 1918          return (spa->spa_is_root);
1871 1919  }
1872 1920  
1873 1921  boolean_t
1874 1922  spa_writeable(spa_t *spa)
1875 1923  {
1876 1924          return (!!(spa->spa_mode & FWRITE));
1877 1925  }
1878 1926  
1879 1927  /*
1880 1928   * Returns true if there is a pending sync task in any of the current
1881 1929   * syncing txg, the current quiescing txg, or the current open txg.
1882 1930   */
1883 1931  boolean_t
1884 1932  spa_has_pending_synctask(spa_t *spa)
1885 1933  {
1886 1934          return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks));
1887 1935  }
1888 1936  
1889 1937  int
1890 1938  spa_mode(spa_t *spa)
1891 1939  {
1892 1940          return (spa->spa_mode);
1893 1941  }
1894 1942  
1895 1943  uint64_t
1896 1944  spa_bootfs(spa_t *spa)
1897 1945  {
1898 1946          return (spa->spa_bootfs);
1899 1947  }
1900 1948  
1901 1949  uint64_t
1902 1950  spa_delegation(spa_t *spa)
1903 1951  {
1904 1952          return (spa->spa_delegation);
1905 1953  }
1906 1954  
1907 1955  objset_t *
1908 1956  spa_meta_objset(spa_t *spa)
1909 1957  {
1910 1958          return (spa->spa_meta_objset);
1911 1959  }
1912 1960  
1913 1961  enum zio_checksum
1914 1962  spa_dedup_checksum(spa_t *spa)
1915 1963  {
1916 1964          return (spa->spa_dedup_checksum);
1917 1965  }
1918 1966  
1919 1967  /*
1920 1968   * Reset pool scan stat per scan pass (or reboot).
1921 1969   */
1922 1970  void
1923 1971  spa_scan_stat_init(spa_t *spa)
1924 1972  {
1925 1973          /* data not stored on disk */
1926 1974          spa->spa_scan_pass_start = gethrestime_sec();
1927 1975          spa->spa_scan_pass_exam = 0;
1928 1976          vdev_scan_stat_init(spa->spa_root_vdev);
1929 1977  }
1930 1978  
1931 1979  /*
1932 1980   * Get scan stats for zpool status reports
1933 1981   */
1934 1982  int
1935 1983  spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1936 1984  {
1937 1985          dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1938 1986  
1939 1987          if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1940 1988                  return (SET_ERROR(ENOENT));
1941 1989          bzero(ps, sizeof (pool_scan_stat_t));
1942 1990  
1943 1991          /* data stored on disk */
1944 1992          ps->pss_func = scn->scn_phys.scn_func;
1945 1993          ps->pss_start_time = scn->scn_phys.scn_start_time;
1946 1994          ps->pss_end_time = scn->scn_phys.scn_end_time;
1947 1995          ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1948 1996          ps->pss_examined = scn->scn_phys.scn_examined;
1949 1997          ps->pss_to_process = scn->scn_phys.scn_to_process;
1950 1998          ps->pss_processed = scn->scn_phys.scn_processed;
1951 1999          ps->pss_errors = scn->scn_phys.scn_errors;
1952 2000          ps->pss_state = scn->scn_phys.scn_state;
1953 2001  
1954 2002          /* data not stored on disk */
1955 2003          ps->pss_pass_start = spa->spa_scan_pass_start;
1956 2004          ps->pss_pass_exam = spa->spa_scan_pass_exam;
1957 2005  
1958 2006          return (0);
1959 2007  }
1960 2008  
1961 2009  boolean_t
1962 2010  spa_debug_enabled(spa_t *spa)
1963 2011  {
1964 2012          return (spa->spa_debug);
1965 2013  }
1966 2014  
1967 2015  int
1968 2016  spa_maxblocksize(spa_t *spa)
1969 2017  {
1970 2018          if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS))
1971 2019                  return (SPA_MAXBLOCKSIZE);
1972 2020          else
1973 2021                  return (SPA_OLD_MAXBLOCKSIZE);
1974 2022  }
  
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