xref: /titanic_41/usr/src/uts/common/fs/zfs/dmu_object.c (revision ff3124eff995e6cd8ebd8c6543648e0670920034)
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