1 /* 2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. 3 * 4 * Copyright (C) 2002-2011 Aleph One Ltd. 5 * for Toby Churchill Ltd and Brightstar Engineering 6 * 7 * Created by Charles Manning <charles@aleph1.co.uk> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include "yaffs_allocator.h" 15 #include "yaffs_guts.h" 16 #include "yaffs_trace.h" 17 #include "yportenv.h" 18 19 /* 20 * Each entry in yaffs_tnode_list and yaffs_obj_list hold blocks 21 * of approx 100 objects that are themn allocated singly. 22 * This is basically a simplified slab allocator. 23 * 24 * We don't use the Linux slab allocator because slab does not allow 25 * us to dump all the objects in one hit when we do a umount and tear 26 * down all the tnodes and objects. slab requires that we first free 27 * the individual objects. 28 * 29 * Once yaffs has been mainlined I shall try to motivate for a change 30 * to slab to provide the extra features we need here. 31 */ 32 33 struct yaffs_tnode_list { 34 struct yaffs_tnode_list *next; 35 struct yaffs_tnode *tnodes; 36 }; 37 38 struct yaffs_obj_list { 39 struct yaffs_obj_list *next; 40 struct yaffs_obj *objects; 41 }; 42 43 struct yaffs_allocator { 44 int n_tnodes_created; 45 struct yaffs_tnode *free_tnodes; 46 int n_free_tnodes; 47 struct yaffs_tnode_list *alloc_tnode_list; 48 49 int n_obj_created; 50 struct list_head free_objs; 51 int n_free_objects; 52 53 struct yaffs_obj_list *allocated_obj_list; 54 }; 55 56 static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev) 57 { 58 struct yaffs_allocator *allocator = 59 (struct yaffs_allocator *)dev->allocator; 60 struct yaffs_tnode_list *tmp; 61 62 if (!allocator) { 63 BUG(); 64 return; 65 } 66 67 while (allocator->alloc_tnode_list) { 68 tmp = allocator->alloc_tnode_list->next; 69 70 kfree(allocator->alloc_tnode_list->tnodes); 71 kfree(allocator->alloc_tnode_list); 72 allocator->alloc_tnode_list = tmp; 73 } 74 75 allocator->free_tnodes = NULL; 76 allocator->n_free_tnodes = 0; 77 allocator->n_tnodes_created = 0; 78 } 79 80 static void yaffs_init_raw_tnodes(struct yaffs_dev *dev) 81 { 82 struct yaffs_allocator *allocator = dev->allocator; 83 84 if (!allocator) { 85 BUG(); 86 return; 87 } 88 89 allocator->alloc_tnode_list = NULL; 90 allocator->free_tnodes = NULL; 91 allocator->n_free_tnodes = 0; 92 allocator->n_tnodes_created = 0; 93 } 94 95 static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes) 96 { 97 struct yaffs_allocator *allocator = 98 (struct yaffs_allocator *)dev->allocator; 99 int i; 100 struct yaffs_tnode *new_tnodes; 101 u8 *mem; 102 struct yaffs_tnode *curr; 103 struct yaffs_tnode *next; 104 struct yaffs_tnode_list *tnl; 105 106 if (!allocator) { 107 BUG(); 108 return YAFFS_FAIL; 109 } 110 111 if (n_tnodes < 1) 112 return YAFFS_OK; 113 114 /* make these things */ 115 new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS); 116 mem = (u8 *) new_tnodes; 117 118 if (!new_tnodes) { 119 yaffs_trace(YAFFS_TRACE_ERROR, 120 "yaffs: Could not allocate Tnodes"); 121 return YAFFS_FAIL; 122 } 123 124 /* New hookup for wide tnodes */ 125 for (i = 0; i < n_tnodes - 1; i++) { 126 curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size]; 127 next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size]; 128 curr->internal[0] = next; 129 } 130 131 curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size]; 132 curr->internal[0] = allocator->free_tnodes; 133 allocator->free_tnodes = (struct yaffs_tnode *)mem; 134 135 allocator->n_free_tnodes += n_tnodes; 136 allocator->n_tnodes_created += n_tnodes; 137 138 /* Now add this bunch of tnodes to a list for freeing up. 139 * NB If we can't add this to the management list it isn't fatal 140 * but it just means we can't free this bunch of tnodes later. 141 */ 142 tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS); 143 if (!tnl) { 144 yaffs_trace(YAFFS_TRACE_ERROR, 145 "Could not add tnodes to management list"); 146 return YAFFS_FAIL; 147 } else { 148 tnl->tnodes = new_tnodes; 149 tnl->next = allocator->alloc_tnode_list; 150 allocator->alloc_tnode_list = tnl; 151 } 152 153 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Tnodes added"); 154 155 return YAFFS_OK; 156 } 157 158 struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev) 159 { 160 struct yaffs_allocator *allocator = 161 (struct yaffs_allocator *)dev->allocator; 162 struct yaffs_tnode *tn = NULL; 163 164 if (!allocator) { 165 BUG(); 166 return NULL; 167 } 168 169 /* If there are none left make more */ 170 if (!allocator->free_tnodes) 171 yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES); 172 173 if (allocator->free_tnodes) { 174 tn = allocator->free_tnodes; 175 allocator->free_tnodes = allocator->free_tnodes->internal[0]; 176 allocator->n_free_tnodes--; 177 } 178 179 return tn; 180 } 181 182 /* FreeTnode frees up a tnode and puts it back on the free list */ 183 void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn) 184 { 185 struct yaffs_allocator *allocator = dev->allocator; 186 187 if (!allocator) { 188 BUG(); 189 return; 190 } 191 192 if (tn) { 193 tn->internal[0] = allocator->free_tnodes; 194 allocator->free_tnodes = tn; 195 allocator->n_free_tnodes++; 196 } 197 dev->checkpoint_blocks_required = 0; /* force recalculation */ 198 } 199 200 /*--------------- yaffs_obj alloaction ------------------------ 201 * 202 * Free yaffs_objs are stored in a list using obj->siblings. 203 * The blocks of allocated objects are stored in a linked list. 204 */ 205 206 static void yaffs_init_raw_objs(struct yaffs_dev *dev) 207 { 208 struct yaffs_allocator *allocator = dev->allocator; 209 210 if (!allocator) { 211 BUG(); 212 return; 213 } 214 215 allocator->allocated_obj_list = NULL; 216 INIT_LIST_HEAD(&allocator->free_objs); 217 allocator->n_free_objects = 0; 218 } 219 220 static void yaffs_deinit_raw_objs(struct yaffs_dev *dev) 221 { 222 struct yaffs_allocator *allocator = dev->allocator; 223 struct yaffs_obj_list *tmp; 224 225 if (!allocator) { 226 BUG(); 227 return; 228 } 229 230 while (allocator->allocated_obj_list) { 231 tmp = allocator->allocated_obj_list->next; 232 kfree(allocator->allocated_obj_list->objects); 233 kfree(allocator->allocated_obj_list); 234 allocator->allocated_obj_list = tmp; 235 } 236 237 INIT_LIST_HEAD(&allocator->free_objs); 238 allocator->n_free_objects = 0; 239 allocator->n_obj_created = 0; 240 } 241 242 static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj) 243 { 244 struct yaffs_allocator *allocator = dev->allocator; 245 int i; 246 struct yaffs_obj *new_objs; 247 struct yaffs_obj_list *list; 248 249 if (!allocator) { 250 BUG(); 251 return YAFFS_FAIL; 252 } 253 254 if (n_obj < 1) 255 return YAFFS_OK; 256 257 /* make these things */ 258 new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS); 259 list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS); 260 261 if (!new_objs || !list) { 262 kfree(new_objs); 263 new_objs = NULL; 264 kfree(list); 265 list = NULL; 266 yaffs_trace(YAFFS_TRACE_ALLOCATE, 267 "Could not allocate more objects"); 268 return YAFFS_FAIL; 269 } 270 271 /* Hook them into the free list */ 272 for (i = 0; i < n_obj; i++) 273 list_add(&new_objs[i].siblings, &allocator->free_objs); 274 275 allocator->n_free_objects += n_obj; 276 allocator->n_obj_created += n_obj; 277 278 /* Now add this bunch of Objects to a list for freeing up. */ 279 280 list->objects = new_objs; 281 list->next = allocator->allocated_obj_list; 282 allocator->allocated_obj_list = list; 283 284 return YAFFS_OK; 285 } 286 287 struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev) 288 { 289 struct yaffs_obj *obj = NULL; 290 struct list_head *lh; 291 struct yaffs_allocator *allocator = dev->allocator; 292 293 if (!allocator) { 294 BUG(); 295 return obj; 296 } 297 298 /* If there are none left make more */ 299 if (list_empty(&allocator->free_objs)) 300 yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS); 301 302 if (!list_empty(&allocator->free_objs)) { 303 lh = allocator->free_objs.next; 304 obj = list_entry(lh, struct yaffs_obj, siblings); 305 list_del_init(lh); 306 allocator->n_free_objects--; 307 } 308 309 return obj; 310 } 311 312 void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj) 313 { 314 315 struct yaffs_allocator *allocator = dev->allocator; 316 317 if (!allocator) { 318 BUG(); 319 return; 320 } 321 322 /* Link into the free list. */ 323 list_add(&obj->siblings, &allocator->free_objs); 324 allocator->n_free_objects++; 325 } 326 327 void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev) 328 { 329 330 if (!dev->allocator) { 331 BUG(); 332 return; 333 } 334 335 yaffs_deinit_raw_tnodes(dev); 336 yaffs_deinit_raw_objs(dev); 337 kfree(dev->allocator); 338 dev->allocator = NULL; 339 } 340 341 void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev) 342 { 343 struct yaffs_allocator *allocator; 344 345 if (dev->allocator) { 346 BUG(); 347 return; 348 } 349 350 allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS); 351 if (allocator) { 352 dev->allocator = allocator; 353 yaffs_init_raw_tnodes(dev); 354 yaffs_init_raw_objs(dev); 355 } 356 } 357