usr/src/uts/common/fs/zfs/dmu_object.c

   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 http://www.opensolaris.org/os/licensing.
  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) 2013, 2015 by Delphix. All rights reserved.
  24  * Copyright 2014 HybridCluster. All rights reserved.
  25  */
  26
  27 #include <sys/dmu.h>
  28 #include <sys/dmu_objset.h>
  29 #include <sys/dmu_tx.h>
  30 #include <sys/dnode.h>
  31 #include <sys/zap.h>
  32 #include <sys/zfeature.h>
  33
  34 uint64_t
  35 dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize,
  36     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
  37 {
  38         uint64_t object;
  39         uint64_t L1_dnode_count = DNODES_PER_BLOCK <<
  40             (DMU_META_DNODE(os)->dn_indblkshift - SPA_BLKPTRSHIFT);
  41         dnode_t *dn = NULL;
  42
  43         mutex_enter(&os->os_obj_lock);
  44         for (;;) {
  45                 object = os->os_obj_next;
  46                 /*
  47                  * Each time we polish off a L1 bp worth of dnodes (2^12
  48                  * objects), move to another L1 bp that's still reasonably
  49                  * sparse (at most 1/4 full). Look from the beginning at most
  50                  * once per txg, but after that keep looking from here.
  51                  * os_scan_dnodes is set during txg sync if enough objects
  52                  * have been freed since the previous rescan to justify
  53                  * backfilling again. If we can't find a suitable block, just
  54                  * keep going from here.
  55                  *
  56                  * Note that dmu_traverse depends on the behavior that we use
  57                  * multiple blocks of the dnode object before going back to
  58                  * reuse objects.  Any change to this algorithm should preserve
  59                  * that property or find another solution to the issues
  60                  * described in traverse_visitbp.
  61                  */
  62
  63                 if (P2PHASE(object, L1_dnode_count) == 0) {
  64                         uint64_t offset;
  65                         int error;
  66                         if (os->os_rescan_dnodes) {
  67                                 offset = 0;
  68                                 os->os_rescan_dnodes = B_FALSE;
  69                         } else {
  70                                 offset = object << DNODE_SHIFT;
  71                         }
  72                         error = dnode_next_offset(DMU_META_DNODE(os),
  73                             DNODE_FIND_HOLE,
  74                             &offset, 2, DNODES_PER_BLOCK >> 2, 0);
  75                         if (error == 0)
  76                                 object = offset >> DNODE_SHIFT;
  77                 }
  78                 os->os_obj_next = ++object;
  79
  80                 /*
  81                  * XXX We should check for an i/o error here and return
  82                  * up to our caller.  Actually we should pre-read it in
  83                  * dmu_tx_assign(), but there is currently no mechanism
  84                  * to do so.
  85                  */
  86                 (void) dnode_hold_impl(os, object, DNODE_MUST_BE_FREE,
  87                     FTAG, &dn);
  88                 if (dn)
  89                         break;
  90
  91                 if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
  92                         os->os_obj_next = object - 1;
  93         }
  94
  95         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
  96         mutex_exit(&os->os_obj_lock);
  97
  98         dmu_tx_add_new_object(tx, dn);
  99         dnode_rele(dn, FTAG);
 100
 101         return (object);
 102 }
 103
 104 int
 105 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 106     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
 107 {
 108         dnode_t *dn;
 109         int err;
 110
 111         if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
 112                 return (SET_ERROR(EBADF));
 113
 114         err = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
 115         if (err)
 116                 return (err);
 117         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
 118         dmu_tx_add_new_object(tx, dn);
 119
 120         dnode_rele(dn, FTAG);
 121
 122         return (0);
 123 }
 124
 125 int
 126 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 127     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
 128 {
 129         dnode_t *dn;
 130         int err;
 131
 132         if (object == DMU_META_DNODE_OBJECT)
 133                 return (SET_ERROR(EBADF));
 134
 135         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 136             FTAG, &dn);
 137         if (err)
 138                 return (err);
 139
 140         dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
 141
 142         dnode_rele(dn, FTAG);
 143         return (err);
 144 }
 145
 146 int
 147 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
 148 {
 149         dnode_t *dn;
 150         int err;
 151
 152         ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
 153
 154         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 155             FTAG, &dn);
 156         if (err)
 157                 return (err);
 158
 159         ASSERT(dn->dn_type != DMU_OT_NONE);
 160         dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
 161         dnode_free(dn, tx);
 162         dnode_rele(dn, FTAG);
 163
 164         return (0);
 165 }
 166
 167 /*
 168  * Return (in *objectp) the next object which is allocated (or a hole)
 169  * after *object, taking into account only objects that may have been modified
 170  * after the specified txg.
 171  */
 172 int
 173 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
 174 {
 175         uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
 176         int error;
 177
 178         error = dnode_next_offset(DMU_META_DNODE(os),
 179             (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
 180
 181         *objectp = offset >> DNODE_SHIFT;
 182
 183         return (error);
 184 }
 185
 186 /*
 187  * Turn this object from old_type into DMU_OTN_ZAP_METADATA, and bump the
 188  * refcount on SPA_FEATURE_EXTENSIBLE_DATASET.
 189  *
 190  * Only for use from syncing context, on MOS objects.
 191  */
 192 void
 193 dmu_object_zapify(objset_t *mos, uint64_t object, dmu_object_type_t old_type,
 194     dmu_tx_t *tx)
 195 {
 196         dnode_t *dn;
 197
 198         ASSERT(dmu_tx_is_syncing(tx));
 199
 200         VERIFY0(dnode_hold(mos, object, FTAG, &dn));
 201         if (dn->dn_type == DMU_OTN_ZAP_METADATA) {
 202                 dnode_rele(dn, FTAG);
 203                 return;
 204         }
 205         ASSERT3U(dn->dn_type, ==, old_type);
 206         ASSERT0(dn->dn_maxblkid);
 207         dn->dn_next_type[tx->tx_txg & TXG_MASK] = dn->dn_type =
 208             DMU_OTN_ZAP_METADATA;
 209         dnode_setdirty(dn, tx);
 210         dnode_rele(dn, FTAG);
 211
 212         mzap_create_impl(mos, object, 0, 0, tx);
 213
 214         spa_feature_incr(dmu_objset_spa(mos),
 215             SPA_FEATURE_EXTENSIBLE_DATASET, tx);
 216 }
 217
 218 void
 219 dmu_object_free_zapified(objset_t *mos, uint64_t object, dmu_tx_t *tx)
 220 {
 221         dnode_t *dn;
 222         dmu_object_type_t t;
 223
 224         ASSERT(dmu_tx_is_syncing(tx));
 225
 226         VERIFY0(dnode_hold(mos, object, FTAG, &dn));
 227         t = dn->dn_type;
 228         dnode_rele(dn, FTAG);
 229
 230         if (t == DMU_OTN_ZAP_METADATA) {
 231                 spa_feature_decr(dmu_objset_spa(mos),
 232                     SPA_FEATURE_EXTENSIBLE_DATASET, tx);
 233         }
 234         VERIFY0(dmu_object_free(mos, object, tx));
 235 }