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      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 2006 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     27 
     28 #include <sys/dmu.h>
     29 #include <sys/dmu_objset.h>
     30 #include <sys/dmu_tx.h>
     31 #include <sys/dnode.h>
     32 
     33 uint64_t
     34 dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize,
     35     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
     36 {
     37 	objset_impl_t *osi = os->os;
     38 	uint64_t object;
     39 	uint64_t L2_dnode_count = DNODES_PER_BLOCK <<
     40 	    (osi->os_meta_dnode->dn_indblkshift - SPA_BLKPTRSHIFT);
     41 	dnode_t *dn = NULL;
     42 	int restarted = B_FALSE;
     43 
     44 	mutex_enter(&osi->os_obj_lock);
     45 	for (;;) {
     46 		object = osi->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 		if (P2PHASE(object, L2_dnode_count) == 0) {
     55 			uint64_t offset = restarted ? object << DNODE_SHIFT : 0;
     56 			int error = dnode_next_offset(osi->os_meta_dnode,
     57 			    B_TRUE, &offset, 2, DNODES_PER_BLOCK >> 2, 0);
     58 			restarted = B_TRUE;
     59 			if (error == 0)
     60 				object = offset >> DNODE_SHIFT;
     61 		}
     62 		osi->os_obj_next = ++object;
     63 
     64 		/*
     65 		 * XXX We should check for an i/o error here and return
     66 		 * up to our caller.  Actually we should pre-read it in
     67 		 * dmu_tx_assign(), but there is currently no mechanism
     68 		 * to do so.
     69 		 */
     70 		(void) dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE,
     71 		    FTAG, &dn);
     72 		if (dn)
     73 			break;
     74 
     75 		if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
     76 			osi->os_obj_next = object - 1;
     77 	}
     78 
     79 	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
     80 	dnode_rele(dn, FTAG);
     81 
     82 	mutex_exit(&osi->os_obj_lock);
     83 
     84 	dmu_tx_add_new_object(tx, os, object);
     85 	return (object);
     86 }
     87 
     88 int
     89 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
     90     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
     91 {
     92 	dnode_t *dn;
     93 	int err;
     94 
     95 	if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
     96 		return (EBADF);
     97 
     98 	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
     99 	if (err)
    100 		return (err);
    101 	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
    102 	dnode_rele(dn, FTAG);
    103 
    104 	dmu_tx_add_new_object(tx, os, object);
    105 	return (0);
    106 }
    107 
    108 int
    109 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
    110     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
    111 {
    112 	dnode_t *dn;
    113 	int err;
    114 
    115 	if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
    116 		return (EBADF);
    117 
    118 	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
    119 	    FTAG, &dn);
    120 	if (err)
    121 		return (err);
    122 	dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
    123 	dnode_rele(dn, FTAG);
    124 
    125 	return (0);
    126 }
    127 
    128 int
    129 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
    130 {
    131 	dnode_t *dn;
    132 	int err;
    133 
    134 	ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
    135 
    136 	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
    137 	    FTAG, &dn);
    138 	if (err)
    139 		return (err);
    140 
    141 	ASSERT(dn->dn_type != DMU_OT_NONE);
    142 	dnode_free(dn, tx);
    143 	dnode_rele(dn, FTAG);
    144 
    145 	return (0);
    146 }
    147 
    148 int
    149 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
    150 {
    151 	uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
    152 	int error;
    153 
    154 	error = dnode_next_offset(os->os->os_meta_dnode,
    155 	    hole, &offset, 0, DNODES_PER_BLOCK, txg);
    156 
    157 	*objectp = offset >> DNODE_SHIFT;
    158 
    159 	return (error);
    160 }
    161