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