NEX-3508 CLONE - Port NEX-2946 Add UNMAP/TRIM functionality to ZFS and illumos
Reviewed by: Josef Sipek <josef.sipek@nexenta.com>
Reviewed by: Alek Pinchuk <alek.pinchuk@nexenta.com>
Conflicts:
    usr/src/uts/common/io/scsi/targets/sd.c
    usr/src/uts/common/sys/scsi/targets/sddef.h

*** 22,32 ****
   * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  /*
!  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
   */
  
  #include <sys/zfs_context.h>
  #include <sys/spa.h>
  #include <sys/vdev_impl.h>
--- 22,32 ----
   * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  /*
!  * Copyright (c) 2013 by Delphix. All rights reserved.
   */
  
  #include <sys/zfs_context.h>
  #include <sys/spa.h>
  #include <sys/vdev_impl.h>
*** 35,92 ****
  
  /*
   * Virtual device vector for the pool's root vdev.
   */
  
- static uint64_t
- vdev_root_core_tvds(vdev_t *vd)
- {
-         uint64_t tvds = 0;
- 
-         for (uint64_t c = 0; c < vd->vdev_children; c++) {
-                 vdev_t *cvd = vd->vdev_child[c];
- 
-                 if (!cvd->vdev_ishole && !cvd->vdev_islog &&
-                     cvd->vdev_ops != &vdev_indirect_ops) {
-                         tvds++;
-                 }
-         }
- 
-         return (tvds);
- }
- 
  /*
   * We should be able to tolerate one failure with absolutely no damage
   * to our metadata.  Two failures will take out space maps, a bunch of
   * indirect block trees, meta dnodes, dnodes, etc.  Probably not a happy
   * place to live.  When we get smarter, we can liberalize this policy.
   * e.g. If we haven't lost two consecutive top-level vdevs, then we are
   * probably fine.  Adding bean counters during alloc/free can make this
   * future guesswork more accurate.
   */
! static boolean_t
! too_many_errors(vdev_t *vd, uint64_t numerrors)
  {
!         uint64_t tvds;
! 
!         if (numerrors == 0)
!                 return (B_FALSE);
! 
!         tvds = vdev_root_core_tvds(vd);
!         ASSERT3U(numerrors, <=, tvds);
! 
!         if (numerrors == tvds)
!                 return (B_TRUE);
! 
!         return (numerrors > spa_missing_tvds_allowed(vd->vdev_spa));
  }
  
  static int
  vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
      uint64_t *ashift)
  {
-         spa_t *spa = vd->vdev_spa;
          int lasterror = 0;
          int numerrors = 0;
  
          if (vd->vdev_children == 0) {
                  vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
--- 35,64 ----
  
  /*
   * Virtual device vector for the pool's root vdev.
   */
  
  /*
   * We should be able to tolerate one failure with absolutely no damage
   * to our metadata.  Two failures will take out space maps, a bunch of
   * indirect block trees, meta dnodes, dnodes, etc.  Probably not a happy
   * place to live.  When we get smarter, we can liberalize this policy.
   * e.g. If we haven't lost two consecutive top-level vdevs, then we are
   * probably fine.  Adding bean counters during alloc/free can make this
   * future guesswork more accurate.
   */
! static int
! too_many_errors(vdev_t *vd, int numerrors)
  {
!         ASSERT3U(numerrors, <=, vd->vdev_children);
!         return (numerrors > 0);
  }
  
  static int
  vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
      uint64_t *ashift)
  {
          int lasterror = 0;
          int numerrors = 0;
  
          if (vd->vdev_children == 0) {
                  vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
*** 102,114 ****
                          lasterror = cvd->vdev_open_error;
                          numerrors++;
                  }
          }
  
-         if (spa_load_state(spa) != SPA_LOAD_NONE)
-                 spa_set_missing_tvds(spa, numerrors);
- 
          if (too_many_errors(vd, numerrors)) {
                  vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
                  return (lasterror);
          }
  
--- 74,83 ----
*** 130,140 ****
  vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
  {
          if (too_many_errors(vd, faulted)) {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
                      VDEV_AUX_NO_REPLICAS);
!         } else if (degraded || faulted) {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
          } else {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
          }
  }
--- 99,109 ----
  vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
  {
          if (too_many_errors(vd, faulted)) {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
                      VDEV_AUX_NO_REPLICAS);
!         } else if (degraded) {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
          } else {
                  vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
          }
  }