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 https://opensource.org/licenses/CDDL-1.0. 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 boolean_t abd_size_alloc_linear(size_t); 95 void abd_gang_add(abd_t *, abd_t *, boolean_t); 96 void abd_free(abd_t *); 97 abd_t *abd_get_offset(abd_t *, size_t); 98 abd_t *abd_get_offset_size(abd_t *, size_t, size_t); 99 abd_t *abd_get_offset_struct(abd_t *, abd_t *, size_t, size_t); 100 abd_t *abd_get_zeros(size_t); 101 abd_t *abd_get_from_buf(void *, size_t); 102 void abd_cache_reap_now(void); 103 104 /* 105 * Conversion to and from a normal buffer 106 */ 107 108 void *abd_to_buf(abd_t *); 109 void *abd_borrow_buf(abd_t *, size_t); 110 void *abd_borrow_buf_copy(abd_t *, size_t); 111 void abd_return_buf(abd_t *, void *, size_t); 112 void abd_return_buf_copy(abd_t *, void *, size_t); 113 void abd_take_ownership_of_buf(abd_t *, boolean_t); 114 void abd_release_ownership_of_buf(abd_t *); 115 116 /* 117 * ABD operations 118 */ 119 120 int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *); 121 int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t, 122 abd_iter_func2_t *, void *); 123 void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t); 124 void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t); 125 void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t); 126 int abd_cmp(abd_t *, abd_t *); 127 int abd_cmp_buf_off(abd_t *, const void *, size_t, size_t); 128 void abd_zero_off(abd_t *, size_t, size_t); 129 void abd_verify(abd_t *); 130 131 void abd_raidz_gen_iterate(abd_t **cabds, abd_t *dabd, 132 ssize_t csize, ssize_t dsize, const unsigned parity, 133 void (*func_raidz_gen)(void **, const void *, size_t, size_t)); 134 void abd_raidz_rec_iterate(abd_t **cabds, abd_t **tabds, 135 ssize_t tsize, const unsigned parity, 136 void (*func_raidz_rec)(void **t, const size_t tsize, void **c, 137 const unsigned *mul), 138 const unsigned *mul); 139 140 /* 141 * Wrappers for calls with offsets of 0 142 */ 143 144 static inline void 145 abd_copy(abd_t *dabd, abd_t *sabd, size_t size) 146 { 147 abd_copy_off(dabd, sabd, 0, 0, size); 148 } 149 150 static inline void 151 abd_copy_from_buf(abd_t *abd, const void *buf, size_t size) 152 { 153 abd_copy_from_buf_off(abd, buf, 0, size); 154 } 155 156 static inline void 157 abd_copy_to_buf(void* buf, abd_t *abd, size_t size) 158 { 159 abd_copy_to_buf_off(buf, abd, 0, size); 160 } 161 162 static inline int 163 abd_cmp_buf(abd_t *abd, const void *buf, size_t size) 164 { 165 return (abd_cmp_buf_off(abd, buf, 0, size)); 166 } 167 168 static inline void 169 abd_zero(abd_t *abd, size_t size) 170 { 171 abd_zero_off(abd, 0, size); 172 } 173 174 /* 175 * ABD type check functions 176 */ 177 static inline boolean_t 178 abd_is_linear(abd_t *abd) 179 { 180 return ((abd->abd_flags & ABD_FLAG_LINEAR) ? B_TRUE : B_FALSE); 181 } 182 183 static inline boolean_t 184 abd_is_linear_page(abd_t *abd) 185 { 186 return ((abd->abd_flags & ABD_FLAG_LINEAR_PAGE) ? B_TRUE : B_FALSE); 187 } 188 189 static inline boolean_t 190 abd_is_gang(abd_t *abd) 191 { 192 return ((abd->abd_flags & ABD_FLAG_GANG) ? B_TRUE : B_FALSE); 193 } 194 195 static inline uint_t 196 abd_get_size(abd_t *abd) 197 { 198 return (abd->abd_size); 199 } 200 201 /* 202 * Module lifecycle 203 * Defined in each specific OS's abd_os.c 204 */ 205 206 void abd_init(void); 207 void abd_fini(void); 208 209 /* 210 * Linux ABD bio functions 211 */ 212 #if defined(__linux__) && defined(_KERNEL) 213 unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t); 214 unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t); 215 #endif 216 217 #ifdef __cplusplus 218 } 219 #endif 220 221 #endif /* _ABD_H */ 222