1 /* 2 * Copyright (C) 2011 Red Hat, Inc. 3 * 4 * This file is released under the GPL. 5 */ 6 7 #include "dm-space-map-common.h" 8 #include "dm-space-map-disk.h" 9 #include "dm-space-map.h" 10 #include "dm-transaction-manager.h" 11 12 #include <linux/list.h> 13 #include <linux/slab.h> 14 #include <linux/export.h> 15 #include <linux/device-mapper.h> 16 17 #define DM_MSG_PREFIX "space map disk" 18 19 /*----------------------------------------------------------------*/ 20 21 /* 22 * Space map interface. 23 */ 24 struct sm_disk { 25 struct dm_space_map sm; 26 27 struct ll_disk ll; 28 struct ll_disk old_ll; 29 30 dm_block_t begin; 31 dm_block_t nr_allocated_this_transaction; 32 }; 33 34 static void sm_disk_destroy(struct dm_space_map *sm) 35 { 36 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 37 38 kfree(smd); 39 } 40 41 static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks) 42 { 43 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 44 45 return sm_ll_extend(&smd->ll, extra_blocks); 46 } 47 48 static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count) 49 { 50 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 51 *count = smd->old_ll.nr_blocks; 52 53 return 0; 54 } 55 56 static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count) 57 { 58 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 59 *count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction; 60 61 return 0; 62 } 63 64 static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b, 65 uint32_t *result) 66 { 67 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 68 return sm_ll_lookup(&smd->ll, b, result); 69 } 70 71 static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b, 72 int *result) 73 { 74 int r; 75 uint32_t count; 76 77 r = sm_disk_get_count(sm, b, &count); 78 if (r) 79 return r; 80 81 *result = count > 1; 82 83 return 0; 84 } 85 86 static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b, 87 uint32_t count) 88 { 89 int r; 90 int32_t nr_allocations; 91 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 92 93 r = sm_ll_insert(&smd->ll, b, count, &nr_allocations); 94 if (!r) { 95 smd->nr_allocated_this_transaction += nr_allocations; 96 } 97 98 return r; 99 } 100 101 static int sm_disk_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e) 102 { 103 int r; 104 int32_t nr_allocations; 105 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 106 107 r = sm_ll_inc(&smd->ll, b, e, &nr_allocations); 108 if (!r) 109 smd->nr_allocated_this_transaction += nr_allocations; 110 111 return r; 112 } 113 114 static int sm_disk_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e) 115 { 116 int r; 117 int32_t nr_allocations; 118 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 119 120 r = sm_ll_dec(&smd->ll, b, e, &nr_allocations); 121 if (!r) 122 smd->nr_allocated_this_transaction += nr_allocations; 123 124 return r; 125 } 126 127 static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b) 128 { 129 int r; 130 int32_t nr_allocations; 131 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 132 133 /* 134 * Any block we allocate has to be free in both the old and current ll. 135 */ 136 r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b); 137 if (r == -ENOSPC) { 138 /* 139 * There's no free block between smd->begin and the end of the metadata device. 140 * We search before smd->begin in case something has been freed. 141 */ 142 r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b); 143 } 144 145 if (r) 146 return r; 147 148 smd->begin = *b + 1; 149 r = sm_ll_inc(&smd->ll, *b, *b + 1, &nr_allocations); 150 if (!r) { 151 smd->nr_allocated_this_transaction += nr_allocations; 152 } 153 154 return r; 155 } 156 157 static int sm_disk_commit(struct dm_space_map *sm) 158 { 159 int r; 160 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 161 162 r = sm_ll_commit(&smd->ll); 163 if (r) 164 return r; 165 166 memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll)); 167 smd->nr_allocated_this_transaction = 0; 168 169 return 0; 170 } 171 172 static int sm_disk_root_size(struct dm_space_map *sm, size_t *result) 173 { 174 *result = sizeof(struct disk_sm_root); 175 176 return 0; 177 } 178 179 static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max) 180 { 181 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 182 struct disk_sm_root root_le; 183 184 root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks); 185 root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated); 186 root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root); 187 root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root); 188 189 if (max < sizeof(root_le)) 190 return -ENOSPC; 191 192 memcpy(where_le, &root_le, sizeof(root_le)); 193 194 return 0; 195 } 196 197 /*----------------------------------------------------------------*/ 198 199 static struct dm_space_map ops = { 200 .destroy = sm_disk_destroy, 201 .extend = sm_disk_extend, 202 .get_nr_blocks = sm_disk_get_nr_blocks, 203 .get_nr_free = sm_disk_get_nr_free, 204 .get_count = sm_disk_get_count, 205 .count_is_more_than_one = sm_disk_count_is_more_than_one, 206 .set_count = sm_disk_set_count, 207 .inc_blocks = sm_disk_inc_blocks, 208 .dec_blocks = sm_disk_dec_blocks, 209 .new_block = sm_disk_new_block, 210 .commit = sm_disk_commit, 211 .root_size = sm_disk_root_size, 212 .copy_root = sm_disk_copy_root, 213 .register_threshold_callback = NULL 214 }; 215 216 struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm, 217 dm_block_t nr_blocks) 218 { 219 int r; 220 struct sm_disk *smd; 221 222 smd = kmalloc(sizeof(*smd), GFP_KERNEL); 223 if (!smd) 224 return ERR_PTR(-ENOMEM); 225 226 smd->begin = 0; 227 smd->nr_allocated_this_transaction = 0; 228 memcpy(&smd->sm, &ops, sizeof(smd->sm)); 229 230 r = sm_ll_new_disk(&smd->ll, tm); 231 if (r) 232 goto bad; 233 234 r = sm_ll_extend(&smd->ll, nr_blocks); 235 if (r) 236 goto bad; 237 238 r = sm_disk_commit(&smd->sm); 239 if (r) 240 goto bad; 241 242 return &smd->sm; 243 244 bad: 245 kfree(smd); 246 return ERR_PTR(r); 247 } 248 EXPORT_SYMBOL_GPL(dm_sm_disk_create); 249 250 struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm, 251 void *root_le, size_t len) 252 { 253 int r; 254 struct sm_disk *smd; 255 256 smd = kmalloc(sizeof(*smd), GFP_KERNEL); 257 if (!smd) 258 return ERR_PTR(-ENOMEM); 259 260 smd->begin = 0; 261 smd->nr_allocated_this_transaction = 0; 262 memcpy(&smd->sm, &ops, sizeof(smd->sm)); 263 264 r = sm_ll_open_disk(&smd->ll, tm, root_le, len); 265 if (r) 266 goto bad; 267 268 r = sm_disk_commit(&smd->sm); 269 if (r) 270 goto bad; 271 272 return &smd->sm; 273 274 bad: 275 kfree(smd); 276 return ERR_PTR(r); 277 } 278 EXPORT_SYMBOL_GPL(dm_sm_disk_open); 279 280 /*----------------------------------------------------------------*/ 281