xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zap_impl.h (revision 66328dd3)
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 #ifndef	_SYS_ZAP_IMPL_H
27 #define	_SYS_ZAP_IMPL_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/zap.h>
32 #include <sys/zfs_context.h>
33 #include <sys/avl.h>
34 
35 #ifdef	__cplusplus
36 extern "C" {
37 #endif
38 
39 extern int fzap_default_block_shift;
40 
41 #define	ZAP_MAGIC 0x2F52AB2AB
42 
43 #define	FZAP_BLOCK_SHIFT(zap)	((zap)->zap_f.zap_block_shift)
44 
45 #define	ZAP_MAXCD		(uint32_t)(-1)
46 #define	ZAP_HASHBITS		28
47 #define	MZAP_ENT_LEN		64
48 #define	MZAP_NAME_LEN		(MZAP_ENT_LEN - 8 - 4 - 2)
49 #define	MZAP_MAX_BLKSHIFT	SPA_MAXBLOCKSHIFT
50 #define	MZAP_MAX_BLKSZ		(1 << MZAP_MAX_BLKSHIFT)
51 
52 typedef struct mzap_ent_phys {
53 	uint64_t mze_value;
54 	uint32_t mze_cd;
55 	uint16_t mze_pad;	/* in case we want to chain them someday */
56 	char mze_name[MZAP_NAME_LEN];
57 } mzap_ent_phys_t;
58 
59 typedef struct mzap_phys {
60 	uint64_t mz_block_type;	/* ZBT_MICRO */
61 	uint64_t mz_salt;
62 	uint64_t mz_pad[6];
63 	mzap_ent_phys_t mz_chunk[1];
64 	/* actually variable size depending on block size */
65 } mzap_phys_t;
66 
67 typedef struct mzap_ent {
68 	avl_node_t mze_node;
69 	int mze_chunkid;
70 	uint64_t mze_hash;
71 	mzap_ent_phys_t mze_phys;
72 } mzap_ent_t;
73 
74 
75 /*
76  * The (fat) zap is stored in one object. It is an array of
77  * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
78  *
79  * ptrtbl fits in first block:
80  * 	[zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
81  *
82  * ptrtbl too big for first block:
83  * 	[zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
84  *
85  */
86 
87 struct dmu_buf;
88 struct zap_leaf;
89 
90 #define	ZBT_LEAF		((1ULL << 63) + 0)
91 #define	ZBT_HEADER		((1ULL << 63) + 1)
92 #define	ZBT_MICRO		((1ULL << 63) + 3)
93 /* any other values are ptrtbl blocks */
94 
95 /*
96  * the embedded pointer table takes up half a block:
97  * block size / entry size (2^3) / 2
98  */
99 #define	ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)
100 
101 /*
102  * The embedded pointer table starts half-way through the block.  Since
103  * the pointer table itself is half the block, it starts at (64-bit)
104  * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
105  */
106 #define	ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
107 	((uint64_t *)(zap)->zap_f.zap_phys) \
108 	[(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]
109 
110 /*
111  * TAKE NOTE:
112  * If zap_phys_t is modified, zap_byteswap() must be modified.
113  */
114 typedef struct zap_phys {
115 	uint64_t zap_block_type;	/* ZBT_HEADER */
116 	uint64_t zap_magic;		/* ZAP_MAGIC */
117 
118 	struct zap_table_phys {
119 		uint64_t zt_blk;	/* starting block number */
120 		uint64_t zt_numblks;	/* number of blocks */
121 		uint64_t zt_shift;	/* bits to index it */
122 		uint64_t zt_nextblk;	/* next (larger) copy start block */
123 		uint64_t zt_blks_copied; /* number source blocks copied */
124 	} zap_ptrtbl;
125 
126 	uint64_t zap_freeblk;		/* the next free block */
127 	uint64_t zap_num_leafs;		/* number of leafs */
128 	uint64_t zap_num_entries;	/* number of entries */
129 	uint64_t zap_salt;		/* salt to stir into hash function */
130 	/*
131 	 * This structure is followed by padding, and then the embedded
132 	 * pointer table.  The embedded pointer table takes up second
133 	 * half of the block.  It is accessed using the
134 	 * ZAP_EMBEDDED_PTRTBL_ENT() macro.
135 	 */
136 } zap_phys_t;
137 
138 typedef struct zap_table_phys zap_table_phys_t;
139 
140 typedef struct zap {
141 	objset_t *zap_objset;
142 	uint64_t zap_object;
143 	struct dmu_buf *zap_dbuf;
144 	krwlock_t zap_rwlock;
145 	int zap_ismicro;
146 	uint64_t zap_salt;
147 	union {
148 		struct {
149 			zap_phys_t *zap_phys;
150 
151 			/*
152 			 * zap_num_entries_mtx protects
153 			 * zap_num_entries
154 			 */
155 			kmutex_t zap_num_entries_mtx;
156 			int zap_block_shift;
157 		} zap_fat;
158 		struct {
159 			mzap_phys_t *zap_phys;
160 			int16_t zap_num_entries;
161 			int16_t zap_num_chunks;
162 			int16_t zap_alloc_next;
163 			avl_tree_t zap_avl;
164 		} zap_micro;
165 	} zap_u;
166 } zap_t;
167 
168 #define	zap_f	zap_u.zap_fat
169 #define	zap_m	zap_u.zap_micro
170 
171 uint64_t zap_hash(zap_t *zap, const char *name);
172 int zap_lockdir(objset_t *os, uint64_t obj, dmu_tx_t *tx,
173     krw_t lti, int fatreader, zap_t **zapp);
174 void zap_unlockdir(zap_t *zap);
175 void zap_pageout(dmu_buf_t *db, void *vmzap);
176 
177 #define	ZAP_HASH_IDX(hash, n) (((n) == 0) ? 0 : ((hash) >> (64 - (n))))
178 
179 void fzap_byteswap(void *buf, size_t size);
180 int fzap_count(zap_t *zap, uint64_t *count);
181 int fzap_lookup(zap_t *zap, const char *name,
182     uint64_t integer_size, uint64_t num_integers, void *buf);
183 int fzap_add(zap_t *zap, const char *name,
184     uint64_t integer_size, uint64_t num_integers,
185     const void *val, dmu_tx_t *tx);
186 int fzap_update(zap_t *zap, const char *name,
187     int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
188 int fzap_length(zap_t *zap, const char *name,
189     uint64_t *integer_size, uint64_t *num_integers);
190 int fzap_remove(zap_t *zap, const char *name, dmu_tx_t *tx);
191 int fzap_cursor_retrieve(zap_t *zap, zap_cursor_t *zc, zap_attribute_t *za);
192 void fzap_get_stats(zap_t *zap, zap_stats_t *zs);
193 void zap_put_leaf(struct zap_leaf *l);
194 
195 int fzap_add_cd(zap_t *zap, const char *name,
196     uint64_t integer_size, uint64_t num_integers,
197     const void *val, uint32_t cd, dmu_tx_t *tx);
198 void fzap_upgrade(zap_t *zap, dmu_tx_t *tx);
199 
200 #ifdef	__cplusplus
201 }
202 #endif
203 
204 #endif /* _SYS_ZAP_IMPL_H */
205