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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 2008 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 			    DNODE_FIND_HOLE,
     58 			    &offset, 2, DNODES_PER_BLOCK >> 2, 0);
     59 			restarted = B_TRUE;
     60 			if (error == 0)
     61 				object = offset >> DNODE_SHIFT;
     62 		}
     63 		osi->os_obj_next = ++object;
     64 
     65 		/*
     66 		 * XXX We should check for an i/o error here and return
     67 		 * up to our caller.  Actually we should pre-read it in
     68 		 * dmu_tx_assign(), but there is currently no mechanism
     69 		 * to do so.
     70 		 */
     71 		(void) dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE,
     72 		    FTAG, &dn);
     73 		if (dn)
     74 			break;
     75 
     76 		if (dmu_object_next(os, &object, B_TRUE, 0) == 0)
     77 			osi->os_obj_next = object - 1;
     78 	}
     79 
     80 	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
     81 	dnode_rele(dn, FTAG);
     82 
     83 	mutex_exit(&osi->os_obj_lock);
     84 
     85 	dmu_tx_add_new_object(tx, os, object);
     86 	return (object);
     87 }
     88 
     89 int
     90 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
     91     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
     92 {
     93 	dnode_t *dn;
     94 	int err;
     95 
     96 	if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
     97 		return (EBADF);
     98 
     99 	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE, FTAG, &dn);
    100 	if (err)
    101 		return (err);
    102 	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);
    103 	dnode_rele(dn, FTAG);
    104 
    105 	dmu_tx_add_new_object(tx, os, object);
    106 	return (0);
    107 }
    108 
    109 int
    110 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
    111     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
    112 {
    113 	dnode_t *dn;
    114 	int err;
    115 
    116 	if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
    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 	dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);
    124 	dnode_rele(dn, FTAG);
    125 
    126 	return (0);
    127 }
    128 
    129 int
    130 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
    131 {
    132 	dnode_t *dn;
    133 	int err;
    134 
    135 	ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
    136 
    137 	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
    138 	    FTAG, &dn);
    139 	if (err)
    140 		return (err);
    141 
    142 	ASSERT(dn->dn_type != DMU_OT_NONE);
    143 	dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
    144 	dnode_free(dn, tx);
    145 	dnode_rele(dn, FTAG);
    146 
    147 	return (0);
    148 }
    149 
    150 int
    151 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
    152 {
    153 	uint64_t offset = (*objectp + 1) << DNODE_SHIFT;
    154 	int error;
    155 
    156 	error = dnode_next_offset(os->os->os_meta_dnode,
    157 	    (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
    158 
    159 	*objectp = offset >> DNODE_SHIFT;
    160 
    161 	return (error);
    162 }
    163