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) 2014 by Chunwei Chen. All rights reserved.
23 * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
24 */
25
26 #ifndef _ABD_H
27 #define _ABD_H
28
29 #include <sys/isa_defs.h>
30 #include <sys/debug.h>
31 #include <sys/zfs_refcount.h>
32 #include <sys/uio.h>
33
34 #ifdef __cplusplus
35 extern "C" {
36 #endif
37
38 typedef enum abd_flags {
39 ABD_FLAG_LINEAR = 1 << 0, /* is buffer linear (or scattered)? */
40 ABD_FLAG_OWNER = 1 << 1, /* does it own its data buffers? */
41 ABD_FLAG_META = 1 << 2, /* does this represent FS metadata? */
42 ABD_FLAG_MULTI_ZONE = 1 << 3, /* pages split over memory zones */
43 ABD_FLAG_MULTI_CHUNK = 1 << 4, /* pages split over multiple chunks */
44 ABD_FLAG_LINEAR_PAGE = 1 << 5, /* linear but allocd from page */
45 ABD_FLAG_GANG = 1 << 6, /* mult ABDs chained together */
46 ABD_FLAG_GANG_FREE = 1 << 7, /* gang ABD is responsible for mem */
47 ABD_FLAG_ZEROS = 1 << 8, /* ABD for zero-filled buffer */
48 ABD_FLAG_ALLOCD = 1 << 9, /* we allocated the abd_t */
49 } abd_flags_t;
50
51 typedef struct abd {
52 abd_flags_t abd_flags;
53 uint_t abd_size; /* excludes scattered abd_offset */
54 list_node_t abd_gang_link;
55 #ifdef ZFS_DEBUG
56 struct abd *abd_parent;
57 zfs_refcount_t abd_children;
58 #endif
59 kmutex_t abd_mtx;
60 union {
61 struct abd_scatter {
62 uint_t abd_offset;
63 #if defined(__FreeBSD__) && defined(_KERNEL)
64 void *abd_chunks[1]; /* actually variable-length */
65 #else
66 uint_t abd_nents;
67 struct scatterlist *abd_sgl;
68 #endif
69 } abd_scatter;
70 struct abd_linear {
71 void *abd_buf;
72 struct scatterlist *abd_sgl; /* for LINEAR_PAGE */
73 } abd_linear;
74 struct abd_gang {
75 list_t abd_gang_chain;
76 } abd_gang;
77 } abd_u;
78 } abd_t;
79
80 typedef int abd_iter_func_t(void *buf, size_t len, void *priv);
81 typedef int abd_iter_func2_t(void *bufa, void *bufb, size_t len, void *priv);
82
83 extern int zfs_abd_scatter_enabled;
84
85 /*
86 * Allocations and deallocations
87 */
88
89 abd_t *abd_alloc(size_t, boolean_t);
90 abd_t *abd_alloc_linear(size_t, boolean_t);
91 abd_t *abd_alloc_gang(void);
92 abd_t *abd_alloc_for_io(size_t, boolean_t);
93 abd_t *abd_alloc_sametype(abd_t *, size_t);
94 void abd_gang_add(abd_t *, abd_t *, boolean_t);
95 void abd_free(abd_t *);
96 abd_t *abd_get_offset(abd_t *, size_t);
97 abd_t *abd_get_offset_size(abd_t *, size_t, size_t);
98 abd_t *abd_get_offset_struct(abd_t *, abd_t *, size_t, size_t);
99 abd_t *abd_get_zeros(size_t);
100 abd_t *abd_get_from_buf(void *, size_t);
101 void abd_cache_reap_now(void);
102
103 /*
104 * Conversion to and from a normal buffer
105 */
106
107 void *abd_to_buf(abd_t *);
108 void *abd_borrow_buf(abd_t *, size_t);
109 void *abd_borrow_buf_copy(abd_t *, size_t);
110 void abd_return_buf(abd_t *, void *, size_t);
111 void abd_return_buf_copy(abd_t *, void *, size_t);
112 void abd_take_ownership_of_buf(abd_t *, boolean_t);
113 void abd_release_ownership_of_buf(abd_t *);
114
115 /*
116 * ABD operations
117 */
118
119 int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *);
120 int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t,
121 abd_iter_func2_t *, void *);
122 void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t);
123 void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t);
124 void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t);
125 int abd_cmp(abd_t *, abd_t *);
126 int abd_cmp_buf_off(abd_t *, const void *, size_t, size_t);
127 void abd_zero_off(abd_t *, size_t, size_t);
128 void abd_verify(abd_t *);
129
130 void abd_raidz_gen_iterate(abd_t **cabds, abd_t *dabd,
131 ssize_t csize, ssize_t dsize, const unsigned parity,
132 void (*func_raidz_gen)(void **, const void *, size_t, size_t));
133 void abd_raidz_rec_iterate(abd_t **cabds, abd_t **tabds,
134 ssize_t tsize, const unsigned parity,
135 void (*func_raidz_rec)(void **t, const size_t tsize, void **c,
136 const unsigned *mul),
137 const unsigned *mul);
138
139 /*
140 * Wrappers for calls with offsets of 0
141 */
142
143 static inline void
abd_copy(abd_t * dabd,abd_t * sabd,size_t size)144 abd_copy(abd_t *dabd, abd_t *sabd, size_t size)
145 {
146 abd_copy_off(dabd, sabd, 0, 0, size);
147 }
148
149 static inline void
abd_copy_from_buf(abd_t * abd,const void * buf,size_t size)150 abd_copy_from_buf(abd_t *abd, const void *buf, size_t size)
151 {
152 abd_copy_from_buf_off(abd, buf, 0, size);
153 }
154
155 static inline void
abd_copy_to_buf(void * buf,abd_t * abd,size_t size)156 abd_copy_to_buf(void* buf, abd_t *abd, size_t size)
157 {
158 abd_copy_to_buf_off(buf, abd, 0, size);
159 }
160
161 static inline int
abd_cmp_buf(abd_t * abd,const void * buf,size_t size)162 abd_cmp_buf(abd_t *abd, const void *buf, size_t size)
163 {
164 return (abd_cmp_buf_off(abd, buf, 0, size));
165 }
166
167 static inline void
abd_zero(abd_t * abd,size_t size)168 abd_zero(abd_t *abd, size_t size)
169 {
170 abd_zero_off(abd, 0, size);
171 }
172
173 /*
174 * ABD type check functions
175 */
176 static inline boolean_t
abd_is_linear(abd_t * abd)177 abd_is_linear(abd_t *abd)
178 {
179 return ((abd->abd_flags & ABD_FLAG_LINEAR) ? B_TRUE : B_FALSE);
180 }
181
182 static inline boolean_t
abd_is_linear_page(abd_t * abd)183 abd_is_linear_page(abd_t *abd)
184 {
185 return ((abd->abd_flags & ABD_FLAG_LINEAR_PAGE) ? B_TRUE : B_FALSE);
186 }
187
188 static inline boolean_t
abd_is_gang(abd_t * abd)189 abd_is_gang(abd_t *abd)
190 {
191 return ((abd->abd_flags & ABD_FLAG_GANG) ? B_TRUE : B_FALSE);
192 }
193
194 static inline uint_t
abd_get_size(abd_t * abd)195 abd_get_size(abd_t *abd)
196 {
197 return (abd->abd_size);
198 }
199
200 /*
201 * Module lifecycle
202 * Defined in each specific OS's abd_os.c
203 */
204
205 void abd_init(void);
206 void abd_fini(void);
207
208 /*
209 * Linux ABD bio functions
210 */
211 #if defined(__linux__) && defined(_KERNEL)
212 unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t);
213 unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t);
214 #endif
215
216 #ifdef __cplusplus
217 }
218 #endif
219
220 #endif /* _ABD_H */
221