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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  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         objset_impl_t *osi = os->os;
  36         uint64_t object;
  37         uint64_t L2_dnode_count = DNODES_PER_BLOCK <<
  38             (osi->os_meta_dnode->dn_indblkshift - SPA_BLKPTRSHIFT);
  39         dnode_t *dn = NULL;
  40         int restarted = B_FALSE;
  41
  42         mutex_enter(&osi->os_obj_lock);
  43         for (;;) {
  44                 object = osi->os_obj_next;
  45                 /*
  46                  * Each time we polish off an L2 bp worth of dnodes
  47                  * (2^13 objects), move to another L2 bp that's still
  48                  * reasonably sparse (at most 1/4 full).  Look from the
  49                  * beginning once, but after that keep looking from here.
  50                  * If we can't find one, just keep going from here.
  51                  */
  52                 if (P2PHASE(object, L2_dnode_count) == 0) {
  53                         uint64_t offset = restarted ? object << DNODE_SHIFT : 0;
  54                         int error = dnode_next_offset(osi->os_meta_dnode,
  55                             DNODE_FIND_HOLE,
  56                             &offset, 2, DNODES_PER_BLOCK >> 2, 0);
  57                         restarted = B_TRUE;
  58                         if (error == 0)
  59                                 object = offset >> DNODE_SHIFT;
  60                 }
  61                 osi->os_obj_next = ++object;
  62
  63                 /*
  64                  * XXX We should check for an i/o error here and return
  65                  * up to our caller.  Actually we should pre-read it in
  66                  * dmu_tx_assign(), but there is currently no mechanism
  67                  * to do so.
  68                  */
  69                 (void) dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE,
  70                     FTAG, &dn);
  71                 if (dn)
  72                         break;
  73
  74                 if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
  75                         osi->os_obj_next = object - 1;
  76         }
  77
  78         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
  79         dnode_rele(dn, FTAG);
  80
  81         mutex_exit(&osi->os_obj_lock);
  82
  83         dmu_tx_add_new_object(tx, os, object);
  84         return (object);
  85 }
  86
  87 int
  88 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
  89     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
  90 {
  91         dnode_t *dn;
  92         int err;
  93
  94         if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
  95                 return (EBADF);
  96
  97         err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
  98         if (err)
  99                 return (err);
 100         dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
 101         dnode_rele(dn, FTAG);
 102
 103         dmu_tx_add_new_object(tx, os, object);
 104         return (0);
 105 }
 106
 107 int
 108 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 109     int blocksize, dmu_object_type_t bonustype, int bonuslen)
 110 {
 111         dnode_t *dn;
 112         dmu_tx_t *tx;
 113         int nblkptr;
 114         int err;
 115
 116         if (object == DMU_META_DNODE_OBJECT)
 117                 return (EBADF);
 118
 119         err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
 120             FTAG, &dn);
 121         if (err)
 122                 return (err);
 123
 124         if (dn->dn_type == ot && dn->dn_datablksz == blocksize &&
 125             dn->dn_bonustype == bonustype && dn->dn_bonuslen == bonuslen) {
 126                 /* nothing is changing, this is a noop */
 127                 dnode_rele(dn, FTAG);
 128                 return (0);
 129         }
 130
 131         tx = dmu_tx_create(os);
 132         dmu_tx_hold_bonus(tx, object);
 133         err = dmu_tx_assign(tx, TXG_WAIT);
 134         if (err) {
 135                 dmu_tx_abort(tx);
 136                 dnode_rele(dn, FTAG);
 137                 return (err);
 138         }
 139
 140         nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
 141
 142         /*
 143          * If we are losing blkptrs or changing the block size this must
 144          * be a new file instance.   We must clear out the previous file
 145          * contents before we can change this type of metadata in the dnode.
 146          */
 147         if (dn->dn_nblkptr > nblkptr || dn->dn_datablksz != blocksize)
 148                 dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
 149
 150         dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
 151
 152         dmu_tx_commit(tx);
 153
 154         dnode_rele(dn, FTAG);
 155
 156         return (0);
 157 }
 158
 159 int
 160 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
 161 {
 162         dnode_t *dn;
 163         int err;
 164
 165         ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
 166
 167         err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
 168             FTAG, &dn);
 169         if (err)
 170                 return (err);
 171
 172         ASSERT(dn->dn_type != DMU_OT_NONE);
 173         dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
 174         dnode_free(dn, tx);
 175         dnode_rele(dn, FTAG);
 176
 177         return (0);
 178 }
 179
 180 int
 181 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
 182 {
 183         uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
 184         int error;
 185
 186         error = dnode_next_offset(os->os->os_meta_dnode,
 187             (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
 188
 189         *objectp = offset >> DNODE_SHIFT;
 190
 191         return (error);
 192 }