module/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 L2_dnode_count = DNODES_PER_BLOCK <<
  40             (DMU_META_DNODE(os)->dn_indblkshift - SPA_BLKPTRSHIFT);
  41         dnode_t *dn = NULL;
  42         int restarted = B_FALSE;
  43
  44         mutex_enter(&os->os_obj_lock);
  45         for (;;) {
  46                 object = os->os_obj_next;
  47                 /*
  48                  * Each time we polish off an L2 bp worth of dnodes
  49                  * (2^13 objects), move to another L2 bp that's still
  50                  * reasonably sparse (at most 1/4 full).  Look from the
  51                  * beginning once, but after that keep looking from here.
  52                  * If we can't find one, just keep going from here.
  53                  *
  54                  * Note that dmu_traverse depends on the behavior that we use
  55                  * multiple blocks of the dnode object before going back to
  56                  * reuse objects.  Any change to this algorithm should preserve
  57                  * that property or find another solution to the issues
  58                  * described in traverse_visitbp.
  59                  */
  60                 if (P2PHASE(object, L2_dnode_count) == 0) {
  61                         uint64_t offset = restarted ? object << DNODE_SHIFT : 0;
  62                         int error = dnode_next_offset(DMU_META_DNODE(os),
  63                             DNODE_FIND_HOLE,
  64                             &offset, 2, DNODES_PER_BLOCK >> 2, 0);
  65                         restarted = B_TRUE;
  66                         if (error == 0)
  67                                 object = offset >> DNODE_SHIFT;
  68                 }
  69                 os->os_obj_next = ++object;
  70
  71                 /*
  72                  * XXX We should check for an i/o error here and return
  73                  * up to our caller.  Actually we should pre-read it in
  74                  * dmu_tx_assign(), but there is currently no mechanism
  75                  * to do so.
  76                  */
  77                 (void) dnode_hold_impl(os, object, DNODE_MUST_BE_FREE,
  78                     FTAG, &dn);
  79                 if (dn)
  80                         break;
  81
  82                 if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
  83                         os->os_obj_next = object - 1;
  84         }
  85
  86         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
  87         dnode_rele(dn, FTAG);
  88
  89         mutex_exit(&os->os_obj_lock);
  90
  91         dmu_tx_add_new_object(tx, os, object);
  92         return (object);
  93 }
  94
  95 int
  96 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
  97     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
  98 {
  99         dnode_t *dn;
 100         int err;
 101
 102         if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
 103                 return (SET_ERROR(EBADF));
 104
 105         err = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
 106         if (err)
 107                 return (err);
 108         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
 109         dnode_rele(dn, FTAG);
 110
 111         dmu_tx_add_new_object(tx, os, object);
 112         return (0);
 113 }
 114
 115 int
 116 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 117     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
 118 {
 119         dnode_t *dn;
 120         int err;
 121
 122         if (object == DMU_META_DNODE_OBJECT)
 123                 return (SET_ERROR(EBADF));
 124
 125         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 126             FTAG, &dn);
 127         if (err)
 128                 return (err);
 129
 130         dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
 131
 132         dnode_rele(dn, FTAG);
 133         return (err);
 134 }
 135
 136 int
 137 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
 138 {
 139         dnode_t *dn;
 140         int err;
 141
 142         ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
 143
 144         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 145             FTAG, &dn);
 146         if (err)
 147                 return (err);
 148
 149         ASSERT(dn->dn_type != DMU_OT_NONE);
 150         dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
 151         dnode_free(dn, tx);
 152         dnode_rele(dn, FTAG);
 153
 154         return (0);
 155 }
 156
 157 /*
 158  * Return (in *objectp) the next object which is allocated (or a hole)
 159  * after *object, taking into account only objects that may have been modified
 160  * after the specified txg.
 161  */
 162 int
 163 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
 164 {
 165         uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
 166         int error;
 167
 168         error = dnode_next_offset(DMU_META_DNODE(os),
 169             (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
 170
 171         *objectp = offset >> DNODE_SHIFT;
 172
 173         return (error);
 174 }
 175
 176 /*
 177  * Turn this object from old_type into DMU_OTN_ZAP_METADATA, and bump the
 178  * refcount on SPA_FEATURE_EXTENSIBLE_DATASET.
 179  *
 180  * Only for use from syncing context, on MOS objects.
 181  */
 182 void
 183 dmu_object_zapify(objset_t *mos, uint64_t object, dmu_object_type_t old_type,
 184     dmu_tx_t *tx)
 185 {
 186         dnode_t *dn;
 187
 188         ASSERT(dmu_tx_is_syncing(tx));
 189
 190         VERIFY0(dnode_hold(mos, object, FTAG, &dn));
 191         if (dn->dn_type == DMU_OTN_ZAP_METADATA) {
 192                 dnode_rele(dn, FTAG);
 193                 return;
 194         }
 195         ASSERT3U(dn->dn_type, ==, old_type);
 196         ASSERT0(dn->dn_maxblkid);
 197         dn->dn_next_type[tx->tx_txg & TXG_MASK] = dn->dn_type =
 198             DMU_OTN_ZAP_METADATA;
 199         dnode_setdirty(dn, tx);
 200         dnode_rele(dn, FTAG);
 201
 202         mzap_create_impl(mos, object, 0, 0, tx);
 203
 204         spa_feature_incr(dmu_objset_spa(mos),
 205             SPA_FEATURE_EXTENSIBLE_DATASET, tx);
 206 }
 207
 208 void
 209 dmu_object_free_zapified(objset_t *mos, uint64_t object, dmu_tx_t *tx)
 210 {
 211         dnode_t *dn;
 212         dmu_object_type_t t;
 213
 214         ASSERT(dmu_tx_is_syncing(tx));
 215
 216         VERIFY0(dnode_hold(mos, object, FTAG, &dn));
 217         t = dn->dn_type;
 218         dnode_rele(dn, FTAG);
 219
 220         if (t == DMU_OTN_ZAP_METADATA) {
 221                 spa_feature_decr(dmu_objset_spa(mos),
 222                     SPA_FEATURE_EXTENSIBLE_DATASET, tx);
 223         }
 224         VERIFY0(dmu_object_free(mos, object, tx));
 225 }
 226
 227 #if defined(_KERNEL) && defined(HAVE_SPL)
 228 EXPORT_SYMBOL(dmu_object_alloc);
 229 EXPORT_SYMBOL(dmu_object_claim);
 230 EXPORT_SYMBOL(dmu_object_reclaim);
 231 EXPORT_SYMBOL(dmu_object_free);
 232 EXPORT_SYMBOL(dmu_object_next);
 233 EXPORT_SYMBOL(dmu_object_zapify);
 234 EXPORT_SYMBOL(dmu_object_free_zapified);
 235 #endif