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 by Delphix. All rights reserved.
  24  */
  25
  26 #include <sys/dmu.h>
  27 #include <sys/dmu_objset.h>
  28 #include <sys/dmu_tx.h>
  29 #include <sys/dnode.h>
  30
  31 uint64_t
  32 dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize,
  33     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
  34 {
  35         uint64_t object;
  36         uint64_t L2_dnode_count = DNODES_PER_BLOCK <<
  37             (DMU_META_DNODE(os)->dn_indblkshift - SPA_BLKPTRSHIFT);
  38         dnode_t *dn = NULL;
  39         int restarted = B_FALSE;
  40
  41         mutex_enter(&os->os_obj_lock);
  42         for (;;) {
  43                 object = os->os_obj_next;
  44                 /*
  45                  * Each time we polish off an L2 bp worth of dnodes
  46                  * (2^13 objects), move to another L2 bp that's still
  47                  * reasonably sparse (at most 1/4 full).  Look from the
  48                  * beginning once, but after that keep looking from here.
  49                  * If we can't find one, just keep going from here.
  50                  */
  51                 if (P2PHASE(object, L2_dnode_count) == 0) {
  52                         uint64_t offset = restarted ? object << DNODE_SHIFT : 0;
  53                         int error = dnode_next_offset(DMU_META_DNODE(os),
  54                             DNODE_FIND_HOLE,
  55                             &offset, 2, DNODES_PER_BLOCK >> 2, 0);
  56                         restarted = B_TRUE;
  57                         if (error == 0)
  58                                 object = offset >> DNODE_SHIFT;
  59                 }
  60                 os->os_obj_next = ++object;
  61
  62                 /*
  63                  * XXX We should check for an i/o error here and return
  64                  * up to our caller.  Actually we should pre-read it in
  65                  * dmu_tx_assign(), but there is currently no mechanism
  66                  * to do so.
  67                  */
  68                 (void) dnode_hold_impl(os, object, DNODE_MUST_BE_FREE,
  69                     FTAG, &dn);
  70                 if (dn)
  71                         break;
  72
  73                 if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
  74                         os->os_obj_next = object - 1;
  75         }
  76
  77         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
  78         dnode_rele(dn, FTAG);
  79
  80         mutex_exit(&os->os_obj_lock);
  81
  82         dmu_tx_add_new_object(tx, os, object);
  83         return (object);
  84 }
  85
  86 int
  87 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
  88     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
  89 {
  90         dnode_t *dn;
  91         int err;
  92
  93         if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
  94                 return (SET_ERROR(EBADF));
  95
  96         err = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
  97         if (err)
  98                 return (err);
  99         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
 100         dnode_rele(dn, FTAG);
 101
 102         dmu_tx_add_new_object(tx, os, object);
 103         return (0);
 104 }
 105
 106 int
 107 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 108     int blocksize, dmu_object_type_t bonustype, int bonuslen)
 109 {
 110         dnode_t *dn;
 111         dmu_tx_t *tx;
 112         int nblkptr;
 113         int err;
 114
 115         if (object == DMU_META_DNODE_OBJECT)
 116                 return (SET_ERROR(EBADF));
 117
 118         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 119             FTAG, &dn);
 120         if (err)
 121                 return (err);
 122
 123         if (dn->dn_type == ot && dn->dn_datablksz == blocksize &&
 124             dn->dn_bonustype == bonustype && dn->dn_bonuslen == bonuslen) {
 125                 /* nothing is changing, this is a noop */
 126                 dnode_rele(dn, FTAG);
 127                 return (0);
 128         }
 129
 130         if (bonustype == DMU_OT_SA) {
 131                 nblkptr = 1;
 132         } else {
 133                 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
 134         }
 135
 136         /*
 137          * If we are losing blkptrs or changing the block size this must
 138          * be a new file instance.   We must clear out the previous file
 139          * contents before we can change this type of metadata in the dnode.
 140          */
 141         if (dn->dn_nblkptr > nblkptr || dn->dn_datablksz != blocksize) {
 142                 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
 143                 if (err)
 144                         goto out;
 145         }
 146
 147         tx = dmu_tx_create(os);
 148         dmu_tx_hold_bonus(tx, object);
 149         err = dmu_tx_assign(tx, TXG_WAIT);
 150         if (err) {
 151                 dmu_tx_abort(tx);
 152                 goto out;
 153         }
 154
 155         dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
 156
 157         dmu_tx_commit(tx);
 158 out:
 159         dnode_rele(dn, FTAG);
 160
 161         return (err);
 162 }
 163
 164 int
 165 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
 166 {
 167         dnode_t *dn;
 168         int err;
 169
 170         ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
 171
 172         err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
 173             FTAG, &dn);
 174         if (err)
 175                 return (err);
 176
 177         ASSERT(dn->dn_type != DMU_OT_NONE);
 178         dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
 179         dnode_free(dn, tx);
 180         dnode_rele(dn, FTAG);
 181
 182         return (0);
 183 }
 184
 185 int
 186 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
 187 {
 188         uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
 189         int error;
 190
 191         error = dnode_next_offset(DMU_META_DNODE(os),
 192             (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
 193
 194         *objectp = offset >> DNODE_SHIFT;
 195
 196         return (error);
 197 }
 198
 199 #if defined(_KERNEL) && defined(HAVE_SPL)
 200 EXPORT_SYMBOL(dmu_object_alloc);
 201 EXPORT_SYMBOL(dmu_object_claim);
 202 EXPORT_SYMBOL(dmu_object_reclaim);
 203 EXPORT_SYMBOL(dmu_object_free);
 204 EXPORT_SYMBOL(dmu_object_next);
 205 #endif