Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * JFFS -- Journaling Flash File System, Linux implementation. |
| 3 | * |
| 4 | * Copyright (C) 1999, 2000 Axis Communications AB. |
| 5 | * |
| 6 | * Created by Finn Hakansson <finn@axis.com>. |
| 7 | * |
| 8 | * This is free software; you can redistribute it and/or modify it |
| 9 | * under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * $Id: jffs_fm.c,v 1.27 2001/09/20 12:29:47 dwmw2 Exp $ |
| 14 | * |
| 15 | * Ported to Linux 2.3.x and MTD: |
| 16 | * Copyright (C) 2000 Alexander Larsson (alex@cendio.se), Cendio Systems AB |
| 17 | * |
| 18 | */ |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/blkdev.h> |
| 21 | #include <linux/jffs.h> |
| 22 | #include "jffs_fm.h" |
| 23 | |
| 24 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE |
| 25 | static int jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset); |
| 26 | #endif |
| 27 | |
| 28 | static struct jffs_fm *jffs_alloc_fm(void); |
| 29 | static void jffs_free_fm(struct jffs_fm *n); |
| 30 | |
| 31 | extern kmem_cache_t *fm_cache; |
| 32 | extern kmem_cache_t *node_cache; |
| 33 | |
Adrian Bunk | 94c9eca | 2005-06-25 14:59:06 -0700 | [diff] [blame] | 34 | #if CONFIG_JFFS_FS_VERBOSE > 0 |
| 35 | void |
| 36 | jffs_print_fmcontrol(struct jffs_fmcontrol *fmc) |
| 37 | { |
| 38 | D(printk("struct jffs_fmcontrol: 0x%p\n", fmc)); |
| 39 | D(printk("{\n")); |
| 40 | D(printk(" %u, /* flash_size */\n", fmc->flash_size)); |
| 41 | D(printk(" %u, /* used_size */\n", fmc->used_size)); |
| 42 | D(printk(" %u, /* dirty_size */\n", fmc->dirty_size)); |
| 43 | D(printk(" %u, /* free_size */\n", fmc->free_size)); |
| 44 | D(printk(" %u, /* sector_size */\n", fmc->sector_size)); |
| 45 | D(printk(" %u, /* min_free_size */\n", fmc->min_free_size)); |
| 46 | D(printk(" %u, /* max_chunk_size */\n", fmc->max_chunk_size)); |
| 47 | D(printk(" 0x%p, /* mtd */\n", fmc->mtd)); |
| 48 | D(printk(" 0x%p, /* head */ " |
| 49 | "(head->offset = 0x%08x)\n", |
| 50 | fmc->head, (fmc->head ? fmc->head->offset : 0))); |
| 51 | D(printk(" 0x%p, /* tail */ " |
| 52 | "(tail->offset + tail->size = 0x%08x)\n", |
| 53 | fmc->tail, |
| 54 | (fmc->tail ? fmc->tail->offset + fmc->tail->size : 0))); |
| 55 | D(printk(" 0x%p, /* head_extra */\n", fmc->head_extra)); |
| 56 | D(printk(" 0x%p, /* tail_extra */\n", fmc->tail_extra)); |
| 57 | D(printk("}\n")); |
| 58 | } |
| 59 | #endif /* CONFIG_JFFS_FS_VERBOSE > 0 */ |
| 60 | |
| 61 | #if CONFIG_JFFS_FS_VERBOSE > 2 |
| 62 | static void |
| 63 | jffs_print_fm(struct jffs_fm *fm) |
| 64 | { |
| 65 | D(printk("struct jffs_fm: 0x%p\n", fm)); |
| 66 | D(printk("{\n")); |
| 67 | D(printk(" 0x%08x, /* offset */\n", fm->offset)); |
| 68 | D(printk(" %u, /* size */\n", fm->size)); |
| 69 | D(printk(" 0x%p, /* prev */\n", fm->prev)); |
| 70 | D(printk(" 0x%p, /* next */\n", fm->next)); |
| 71 | D(printk(" 0x%p, /* nodes */\n", fm->nodes)); |
| 72 | D(printk("}\n")); |
| 73 | } |
| 74 | #endif /* CONFIG_JFFS_FS_VERBOSE > 2 */ |
| 75 | |
| 76 | #if 0 |
| 77 | void |
| 78 | jffs_print_node_ref(struct jffs_node_ref *ref) |
| 79 | { |
| 80 | D(printk("struct jffs_node_ref: 0x%p\n", ref)); |
| 81 | D(printk("{\n")); |
| 82 | D(printk(" 0x%p, /* node */\n", ref->node)); |
| 83 | D(printk(" 0x%p, /* next */\n", ref->next)); |
| 84 | D(printk("}\n")); |
| 85 | } |
| 86 | #endif /* 0 */ |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | /* This function creates a new shiny flash memory control structure. */ |
| 89 | struct jffs_fmcontrol * |
| 90 | jffs_build_begin(struct jffs_control *c, int unit) |
| 91 | { |
| 92 | struct jffs_fmcontrol *fmc; |
| 93 | struct mtd_info *mtd; |
| 94 | |
| 95 | D3(printk("jffs_build_begin()\n")); |
| 96 | fmc = (struct jffs_fmcontrol *)kmalloc(sizeof(struct jffs_fmcontrol), |
| 97 | GFP_KERNEL); |
| 98 | if (!fmc) { |
| 99 | D(printk("jffs_build_begin(): Allocation of " |
| 100 | "struct jffs_fmcontrol failed!\n")); |
| 101 | return (struct jffs_fmcontrol *)0; |
| 102 | } |
| 103 | DJM(no_jffs_fmcontrol++); |
| 104 | |
| 105 | mtd = get_mtd_device(NULL, unit); |
| 106 | |
| 107 | if (!mtd) { |
| 108 | kfree(fmc); |
| 109 | DJM(no_jffs_fmcontrol--); |
| 110 | return NULL; |
| 111 | } |
| 112 | |
| 113 | /* Retrieve the size of the flash memory. */ |
| 114 | fmc->flash_size = mtd->size; |
| 115 | D3(printk(" fmc->flash_size = %d bytes\n", fmc->flash_size)); |
| 116 | |
| 117 | fmc->used_size = 0; |
| 118 | fmc->dirty_size = 0; |
| 119 | fmc->free_size = mtd->size; |
| 120 | fmc->sector_size = mtd->erasesize; |
| 121 | fmc->max_chunk_size = fmc->sector_size >> 1; |
| 122 | /* min_free_size: |
| 123 | 1 sector, obviously. |
| 124 | + 1 x max_chunk_size, for when a nodes overlaps the end of a sector |
| 125 | + 1 x max_chunk_size again, which ought to be enough to handle |
| 126 | the case where a rename causes a name to grow, and GC has |
| 127 | to write out larger nodes than the ones it's obsoleting. |
| 128 | We should fix it so it doesn't have to write the name |
| 129 | _every_ time. Later. |
| 130 | + another 2 sectors because people keep getting GC stuck and |
| 131 | we don't know why. This scares me - I want formal proof |
| 132 | of correctness of whatever number we put here. dwmw2. |
| 133 | */ |
| 134 | fmc->min_free_size = fmc->sector_size << 2; |
| 135 | fmc->mtd = mtd; |
| 136 | fmc->c = c; |
| 137 | fmc->head = NULL; |
| 138 | fmc->tail = NULL; |
| 139 | fmc->head_extra = NULL; |
| 140 | fmc->tail_extra = NULL; |
| 141 | init_MUTEX(&fmc->biglock); |
| 142 | return fmc; |
| 143 | } |
| 144 | |
| 145 | |
| 146 | /* When the flash memory scan has completed, this function should be called |
| 147 | before use of the control structure. */ |
| 148 | void |
| 149 | jffs_build_end(struct jffs_fmcontrol *fmc) |
| 150 | { |
| 151 | D3(printk("jffs_build_end()\n")); |
| 152 | |
| 153 | if (!fmc->head) { |
| 154 | fmc->head = fmc->head_extra; |
| 155 | fmc->tail = fmc->tail_extra; |
| 156 | } |
| 157 | else if (fmc->head_extra) { |
| 158 | fmc->tail_extra->next = fmc->head; |
| 159 | fmc->head->prev = fmc->tail_extra; |
| 160 | fmc->head = fmc->head_extra; |
| 161 | } |
| 162 | fmc->head_extra = NULL; /* These two instructions should be omitted. */ |
| 163 | fmc->tail_extra = NULL; |
| 164 | D3(jffs_print_fmcontrol(fmc)); |
| 165 | } |
| 166 | |
| 167 | |
| 168 | /* Call this function when the file system is unmounted. This function |
| 169 | frees all memory used by this module. */ |
| 170 | void |
| 171 | jffs_cleanup_fmcontrol(struct jffs_fmcontrol *fmc) |
| 172 | { |
| 173 | if (fmc) { |
| 174 | struct jffs_fm *next = fmc->head; |
| 175 | while (next) { |
| 176 | struct jffs_fm *cur = next; |
| 177 | next = next->next; |
| 178 | jffs_free_fm(cur); |
| 179 | } |
| 180 | put_mtd_device(fmc->mtd); |
| 181 | kfree(fmc); |
| 182 | DJM(no_jffs_fmcontrol--); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | |
| 187 | /* This function returns the size of the first chunk of free space on the |
| 188 | flash memory. This function will return something nonzero if the flash |
| 189 | memory contains any free space. */ |
| 190 | __u32 |
| 191 | jffs_free_size1(struct jffs_fmcontrol *fmc) |
| 192 | { |
| 193 | __u32 head; |
| 194 | __u32 tail; |
| 195 | __u32 end = fmc->flash_size; |
| 196 | |
| 197 | if (!fmc->head) { |
| 198 | /* There is nothing on the flash. */ |
| 199 | return fmc->flash_size; |
| 200 | } |
| 201 | |
| 202 | /* Compute the beginning and ending of the contents of the flash. */ |
| 203 | head = fmc->head->offset; |
| 204 | tail = fmc->tail->offset + fmc->tail->size; |
| 205 | if (tail == end) { |
| 206 | tail = 0; |
| 207 | } |
| 208 | ASSERT(else if (tail > end) { |
| 209 | printk(KERN_WARNING "jffs_free_size1(): tail > end\n"); |
| 210 | tail = 0; |
| 211 | }); |
| 212 | |
| 213 | if (head <= tail) { |
| 214 | return end - tail; |
| 215 | } |
| 216 | else { |
| 217 | return head - tail; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | /* This function will return something nonzero in case there are two free |
| 222 | areas on the flash. Like this: |
| 223 | |
| 224 | +----------------+------------------+----------------+ |
| 225 | | FREE 1 | USED / DIRTY | FREE 2 | |
| 226 | +----------------+------------------+----------------+ |
| 227 | fmc->head -----^ |
| 228 | fmc->tail ------------------------^ |
| 229 | |
| 230 | The value returned, will be the size of the first empty area on the |
| 231 | flash, in this case marked "FREE 1". */ |
| 232 | __u32 |
| 233 | jffs_free_size2(struct jffs_fmcontrol *fmc) |
| 234 | { |
| 235 | if (fmc->head) { |
| 236 | __u32 head = fmc->head->offset; |
| 237 | __u32 tail = fmc->tail->offset + fmc->tail->size; |
| 238 | if (tail == fmc->flash_size) { |
| 239 | tail = 0; |
| 240 | } |
| 241 | |
| 242 | if (tail >= head) { |
| 243 | return head; |
| 244 | } |
| 245 | } |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | |
| 250 | /* Allocate a chunk of flash memory. If there is enough space on the |
| 251 | device, a reference to the associated node is stored in the jffs_fm |
| 252 | struct. */ |
| 253 | int |
| 254 | jffs_fmalloc(struct jffs_fmcontrol *fmc, __u32 size, struct jffs_node *node, |
| 255 | struct jffs_fm **result) |
| 256 | { |
| 257 | struct jffs_fm *fm; |
| 258 | __u32 free_chunk_size1; |
| 259 | __u32 free_chunk_size2; |
| 260 | |
| 261 | D2(printk("jffs_fmalloc(): fmc = 0x%p, size = %d, " |
| 262 | "node = 0x%p\n", fmc, size, node)); |
| 263 | |
| 264 | *result = NULL; |
| 265 | |
| 266 | if (!(fm = jffs_alloc_fm())) { |
| 267 | D(printk("jffs_fmalloc(): kmalloc() failed! (fm)\n")); |
| 268 | return -ENOMEM; |
| 269 | } |
| 270 | |
| 271 | free_chunk_size1 = jffs_free_size1(fmc); |
| 272 | free_chunk_size2 = jffs_free_size2(fmc); |
| 273 | if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) { |
| 274 | printk(KERN_WARNING "Free size accounting screwed\n"); |
| 275 | printk(KERN_WARNING "free_chunk_size1 == 0x%x, free_chunk_size2 == 0x%x, fmc->free_size == 0x%x\n", free_chunk_size1, free_chunk_size2, fmc->free_size); |
| 276 | } |
| 277 | |
| 278 | D3(printk("jffs_fmalloc(): free_chunk_size1 = %u, " |
| 279 | "free_chunk_size2 = %u\n", |
| 280 | free_chunk_size1, free_chunk_size2)); |
| 281 | |
| 282 | if (size <= free_chunk_size1) { |
| 283 | if (!(fm->nodes = (struct jffs_node_ref *) |
| 284 | kmalloc(sizeof(struct jffs_node_ref), |
| 285 | GFP_KERNEL))) { |
| 286 | D(printk("jffs_fmalloc(): kmalloc() failed! " |
| 287 | "(node_ref)\n")); |
| 288 | jffs_free_fm(fm); |
| 289 | return -ENOMEM; |
| 290 | } |
| 291 | DJM(no_jffs_node_ref++); |
| 292 | fm->nodes->node = node; |
| 293 | fm->nodes->next = NULL; |
| 294 | if (fmc->tail) { |
| 295 | fm->offset = fmc->tail->offset + fmc->tail->size; |
| 296 | if (fm->offset == fmc->flash_size) { |
| 297 | fm->offset = 0; |
| 298 | } |
| 299 | ASSERT(else if (fm->offset > fmc->flash_size) { |
| 300 | printk(KERN_WARNING "jffs_fmalloc(): " |
| 301 | "offset > flash_end\n"); |
| 302 | fm->offset = 0; |
| 303 | }); |
| 304 | } |
| 305 | else { |
| 306 | /* There don't have to be files in the file |
| 307 | system yet. */ |
| 308 | fm->offset = 0; |
| 309 | } |
| 310 | fm->size = size; |
| 311 | fmc->free_size -= size; |
| 312 | fmc->used_size += size; |
| 313 | } |
| 314 | else if (size > free_chunk_size2) { |
| 315 | printk(KERN_WARNING "JFFS: Tried to allocate a too " |
| 316 | "large flash memory chunk. (size = %u)\n", size); |
| 317 | jffs_free_fm(fm); |
| 318 | return -ENOSPC; |
| 319 | } |
| 320 | else { |
| 321 | fm->offset = fmc->tail->offset + fmc->tail->size; |
| 322 | fm->size = free_chunk_size1; |
| 323 | fm->nodes = NULL; |
| 324 | fmc->free_size -= fm->size; |
| 325 | fmc->dirty_size += fm->size; /* Changed by simonk. This seemingly fixes a |
| 326 | bug that caused infinite garbage collection. |
| 327 | It previously set fmc->dirty_size to size (which is the |
| 328 | size of the requested chunk). |
| 329 | */ |
| 330 | } |
| 331 | |
| 332 | fm->next = NULL; |
| 333 | if (!fmc->head) { |
| 334 | fm->prev = NULL; |
| 335 | fmc->head = fm; |
| 336 | fmc->tail = fm; |
| 337 | } |
| 338 | else { |
| 339 | fm->prev = fmc->tail; |
| 340 | fmc->tail->next = fm; |
| 341 | fmc->tail = fm; |
| 342 | } |
| 343 | |
| 344 | D3(jffs_print_fmcontrol(fmc)); |
| 345 | D3(jffs_print_fm(fm)); |
| 346 | *result = fm; |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | |
| 351 | /* The on-flash space is not needed anymore by the passed node. Remove |
| 352 | the reference to the node from the node list. If the data chunk in |
| 353 | the flash memory isn't used by any more nodes anymore (fm->nodes == 0), |
| 354 | then mark that chunk as dirty. */ |
| 355 | int |
| 356 | jffs_fmfree(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, struct jffs_node *node) |
| 357 | { |
| 358 | struct jffs_node_ref *ref; |
| 359 | struct jffs_node_ref *prev; |
| 360 | ASSERT(int del = 0); |
| 361 | |
| 362 | D2(printk("jffs_fmfree(): node->ino = %u, node->version = %u\n", |
| 363 | node->ino, node->version)); |
| 364 | |
| 365 | ASSERT(if (!fmc || !fm || !fm->nodes) { |
| 366 | printk(KERN_ERR "jffs_fmfree(): fmc: 0x%p, fm: 0x%p, " |
| 367 | "fm->nodes: 0x%p\n", |
| 368 | fmc, fm, (fm ? fm->nodes : NULL)); |
| 369 | return -1; |
| 370 | }); |
| 371 | |
| 372 | /* Find the reference to the node that is going to be removed |
| 373 | and remove it. */ |
| 374 | for (ref = fm->nodes, prev = NULL; ref; ref = ref->next) { |
| 375 | if (ref->node == node) { |
| 376 | if (prev) { |
| 377 | prev->next = ref->next; |
| 378 | } |
| 379 | else { |
| 380 | fm->nodes = ref->next; |
| 381 | } |
| 382 | kfree(ref); |
| 383 | DJM(no_jffs_node_ref--); |
| 384 | ASSERT(del = 1); |
| 385 | break; |
| 386 | } |
| 387 | prev = ref; |
| 388 | } |
| 389 | |
| 390 | /* If the data chunk in the flash memory isn't used anymore |
| 391 | just mark it as obsolete. */ |
| 392 | if (!fm->nodes) { |
| 393 | /* No node uses this chunk so let's remove it. */ |
| 394 | fmc->used_size -= fm->size; |
| 395 | fmc->dirty_size += fm->size; |
| 396 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE |
| 397 | if (jffs_mark_obsolete(fmc, fm->offset) < 0) { |
| 398 | D1(printk("jffs_fmfree(): Failed to mark an on-flash " |
| 399 | "node obsolete!\n")); |
| 400 | return -1; |
| 401 | } |
| 402 | #endif |
| 403 | } |
| 404 | |
| 405 | ASSERT(if (!del) { |
| 406 | printk(KERN_WARNING "***jffs_fmfree(): " |
| 407 | "Didn't delete any node reference!\n"); |
| 408 | }); |
| 409 | |
| 410 | return 0; |
| 411 | } |
| 412 | |
| 413 | |
| 414 | /* This allocation function is used during the initialization of |
| 415 | the file system. */ |
| 416 | struct jffs_fm * |
| 417 | jffs_fmalloced(struct jffs_fmcontrol *fmc, __u32 offset, __u32 size, |
| 418 | struct jffs_node *node) |
| 419 | { |
| 420 | struct jffs_fm *fm; |
| 421 | |
| 422 | D3(printk("jffs_fmalloced()\n")); |
| 423 | |
| 424 | if (!(fm = jffs_alloc_fm())) { |
| 425 | D(printk("jffs_fmalloced(0x%p, %u, %u, 0x%p): failed!\n", |
| 426 | fmc, offset, size, node)); |
| 427 | return NULL; |
| 428 | } |
| 429 | fm->offset = offset; |
| 430 | fm->size = size; |
| 431 | fm->prev = NULL; |
| 432 | fm->next = NULL; |
| 433 | fm->nodes = NULL; |
| 434 | if (node) { |
| 435 | /* `node' exists and it should be associated with the |
| 436 | jffs_fm structure `fm'. */ |
| 437 | if (!(fm->nodes = (struct jffs_node_ref *) |
| 438 | kmalloc(sizeof(struct jffs_node_ref), |
| 439 | GFP_KERNEL))) { |
| 440 | D(printk("jffs_fmalloced(): !fm->nodes\n")); |
| 441 | jffs_free_fm(fm); |
| 442 | return NULL; |
| 443 | } |
| 444 | DJM(no_jffs_node_ref++); |
| 445 | fm->nodes->node = node; |
| 446 | fm->nodes->next = NULL; |
| 447 | fmc->used_size += size; |
| 448 | fmc->free_size -= size; |
| 449 | } |
| 450 | else { |
| 451 | /* If there is no node, then this is just a chunk of dirt. */ |
| 452 | fmc->dirty_size += size; |
| 453 | fmc->free_size -= size; |
| 454 | } |
| 455 | |
| 456 | if (fmc->head_extra) { |
| 457 | fm->prev = fmc->tail_extra; |
| 458 | fmc->tail_extra->next = fm; |
| 459 | fmc->tail_extra = fm; |
| 460 | } |
| 461 | else if (!fmc->head) { |
| 462 | fmc->head = fm; |
| 463 | fmc->tail = fm; |
| 464 | } |
| 465 | else if (fmc->tail->offset + fmc->tail->size < offset) { |
| 466 | fmc->head_extra = fm; |
| 467 | fmc->tail_extra = fm; |
| 468 | } |
| 469 | else { |
| 470 | fm->prev = fmc->tail; |
| 471 | fmc->tail->next = fm; |
| 472 | fmc->tail = fm; |
| 473 | } |
| 474 | D3(jffs_print_fmcontrol(fmc)); |
| 475 | D3(jffs_print_fm(fm)); |
| 476 | return fm; |
| 477 | } |
| 478 | |
| 479 | |
| 480 | /* Add a new node to an already existing jffs_fm struct. */ |
| 481 | int |
| 482 | jffs_add_node(struct jffs_node *node) |
| 483 | { |
| 484 | struct jffs_node_ref *ref; |
| 485 | |
| 486 | D3(printk("jffs_add_node(): ino = %u\n", node->ino)); |
| 487 | |
| 488 | ref = (struct jffs_node_ref *)kmalloc(sizeof(struct jffs_node_ref), |
| 489 | GFP_KERNEL); |
| 490 | if (!ref) |
| 491 | return -ENOMEM; |
| 492 | |
| 493 | DJM(no_jffs_node_ref++); |
| 494 | ref->node = node; |
| 495 | ref->next = node->fm->nodes; |
| 496 | node->fm->nodes = ref; |
| 497 | return 0; |
| 498 | } |
| 499 | |
| 500 | |
| 501 | /* Free a part of some allocated space. */ |
| 502 | void |
| 503 | jffs_fmfree_partly(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, __u32 size) |
| 504 | { |
| 505 | D1(printk("***jffs_fmfree_partly(): fm = 0x%p, fm->nodes = 0x%p, " |
| 506 | "fm->nodes->node->ino = %u, size = %u\n", |
| 507 | fm, (fm ? fm->nodes : 0), |
| 508 | (!fm ? 0 : (!fm->nodes ? 0 : fm->nodes->node->ino)), size)); |
| 509 | |
| 510 | if (fm->nodes) { |
| 511 | kfree(fm->nodes); |
| 512 | DJM(no_jffs_node_ref--); |
| 513 | fm->nodes = NULL; |
| 514 | } |
| 515 | fmc->used_size -= fm->size; |
| 516 | if (fm == fmc->tail) { |
| 517 | fm->size -= size; |
| 518 | fmc->free_size += size; |
| 519 | } |
| 520 | fmc->dirty_size += fm->size; |
| 521 | } |
| 522 | |
| 523 | |
| 524 | /* Find the jffs_fm struct that contains the end of the data chunk that |
| 525 | begins at the logical beginning of the flash memory and spans `size' |
| 526 | bytes. If we want to erase a sector of the flash memory, we use this |
| 527 | function to find where the sector limit cuts a chunk of data. */ |
| 528 | struct jffs_fm * |
| 529 | jffs_cut_node(struct jffs_fmcontrol *fmc, __u32 size) |
| 530 | { |
| 531 | struct jffs_fm *fm; |
| 532 | __u32 pos = 0; |
| 533 | |
| 534 | if (size == 0) { |
| 535 | return NULL; |
| 536 | } |
| 537 | |
| 538 | ASSERT(if (!fmc) { |
| 539 | printk(KERN_ERR "jffs_cut_node(): fmc == NULL\n"); |
| 540 | return NULL; |
| 541 | }); |
| 542 | |
| 543 | fm = fmc->head; |
| 544 | |
| 545 | while (fm) { |
| 546 | pos += fm->size; |
| 547 | if (pos < size) { |
| 548 | fm = fm->next; |
| 549 | } |
| 550 | else if (pos > size) { |
| 551 | break; |
| 552 | } |
| 553 | else { |
| 554 | fm = NULL; |
| 555 | break; |
| 556 | } |
| 557 | } |
| 558 | |
| 559 | return fm; |
| 560 | } |
| 561 | |
| 562 | |
| 563 | /* Move the head of the fmc structures and delete the obsolete parts. */ |
| 564 | void |
| 565 | jffs_sync_erase(struct jffs_fmcontrol *fmc, int erased_size) |
| 566 | { |
| 567 | struct jffs_fm *fm; |
| 568 | struct jffs_fm *del; |
| 569 | |
| 570 | ASSERT(if (!fmc) { |
| 571 | printk(KERN_ERR "jffs_sync_erase(): fmc == NULL\n"); |
| 572 | return; |
| 573 | }); |
| 574 | |
| 575 | fmc->dirty_size -= erased_size; |
| 576 | fmc->free_size += erased_size; |
| 577 | |
| 578 | for (fm = fmc->head; fm && (erased_size > 0);) { |
| 579 | if (erased_size >= fm->size) { |
| 580 | erased_size -= fm->size; |
| 581 | del = fm; |
| 582 | fm = fm->next; |
| 583 | fm->prev = NULL; |
| 584 | fmc->head = fm; |
| 585 | jffs_free_fm(del); |
| 586 | } |
| 587 | else { |
| 588 | fm->size -= erased_size; |
| 589 | fm->offset += erased_size; |
| 590 | break; |
| 591 | } |
| 592 | } |
| 593 | } |
| 594 | |
| 595 | |
| 596 | /* Return the oldest used node in the flash memory. */ |
| 597 | struct jffs_node * |
| 598 | jffs_get_oldest_node(struct jffs_fmcontrol *fmc) |
| 599 | { |
| 600 | struct jffs_fm *fm; |
| 601 | struct jffs_node_ref *nref; |
| 602 | struct jffs_node *node = NULL; |
| 603 | |
| 604 | ASSERT(if (!fmc) { |
| 605 | printk(KERN_ERR "jffs_get_oldest_node(): fmc == NULL\n"); |
| 606 | return NULL; |
| 607 | }); |
| 608 | |
| 609 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next); |
| 610 | |
| 611 | if (!fm) { |
| 612 | return NULL; |
| 613 | } |
| 614 | |
| 615 | /* The oldest node is the last one in the reference list. This list |
| 616 | shouldn't be too long; just one or perhaps two elements. */ |
| 617 | for (nref = fm->nodes; nref; nref = nref->next) { |
| 618 | node = nref->node; |
| 619 | } |
| 620 | |
| 621 | D2(printk("jffs_get_oldest_node(): ino = %u, version = %u\n", |
| 622 | (node ? node->ino : 0), (node ? node->version : 0))); |
| 623 | |
| 624 | return node; |
| 625 | } |
| 626 | |
| 627 | |
| 628 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE |
| 629 | |
| 630 | /* Mark an on-flash node as obsolete. |
| 631 | |
| 632 | Note that this is just an optimization that isn't necessary for the |
| 633 | filesystem to work. */ |
| 634 | |
| 635 | static int |
| 636 | jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset) |
| 637 | { |
| 638 | /* The `accurate_pos' holds the position of the accurate byte |
| 639 | in the jffs_raw_inode structure that we are going to mark |
| 640 | as obsolete. */ |
| 641 | __u32 accurate_pos = fm_offset + JFFS_RAW_INODE_ACCURATE_OFFSET; |
| 642 | unsigned char zero = 0x00; |
| 643 | size_t len; |
| 644 | |
| 645 | D3(printk("jffs_mark_obsolete(): accurate_pos = %u\n", accurate_pos)); |
| 646 | ASSERT(if (!fmc) { |
| 647 | printk(KERN_ERR "jffs_mark_obsolete(): fmc == NULL\n"); |
| 648 | return -1; |
| 649 | }); |
| 650 | |
| 651 | /* Write 0x00 to the raw inode's accurate member. Don't care |
| 652 | about the return value. */ |
| 653 | MTD_WRITE(fmc->mtd, accurate_pos, 1, &len, &zero); |
| 654 | return 0; |
| 655 | } |
| 656 | |
| 657 | #endif /* JFFS_MARK_OBSOLETE */ |
| 658 | |
| 659 | /* check if it's possible to erase the wanted range, and if not, return |
| 660 | * the range that IS erasable, or a negative error code. |
| 661 | */ |
| 662 | static long |
| 663 | jffs_flash_erasable_size(struct mtd_info *mtd, __u32 offset, __u32 size) |
| 664 | { |
| 665 | u_long ssize; |
| 666 | |
| 667 | /* assume that sector size for a partition is constant even |
| 668 | * if it spans more than one chip (you usually put the same |
| 669 | * type of chips in a system) |
| 670 | */ |
| 671 | |
| 672 | ssize = mtd->erasesize; |
| 673 | |
| 674 | if (offset % ssize) { |
| 675 | printk(KERN_WARNING "jffs_flash_erasable_size() given non-aligned offset %x (erasesize %lx)\n", offset, ssize); |
| 676 | /* The offset is not sector size aligned. */ |
| 677 | return -1; |
| 678 | } |
| 679 | else if (offset > mtd->size) { |
| 680 | printk(KERN_WARNING "jffs_flash_erasable_size given offset off the end of device (%x > %x)\n", offset, mtd->size); |
| 681 | return -2; |
| 682 | } |
| 683 | else if (offset + size > mtd->size) { |
| 684 | printk(KERN_WARNING "jffs_flash_erasable_size() given length which runs off the end of device (ofs %x + len %x = %x, > %x)\n", offset,size, offset+size, mtd->size); |
| 685 | return -3; |
| 686 | } |
| 687 | |
| 688 | return (size / ssize) * ssize; |
| 689 | } |
| 690 | |
| 691 | |
| 692 | /* How much dirty flash memory is possible to erase at the moment? */ |
| 693 | long |
| 694 | jffs_erasable_size(struct jffs_fmcontrol *fmc) |
| 695 | { |
| 696 | struct jffs_fm *fm; |
| 697 | __u32 size = 0; |
| 698 | long ret; |
| 699 | |
| 700 | ASSERT(if (!fmc) { |
| 701 | printk(KERN_ERR "jffs_erasable_size(): fmc = NULL\n"); |
| 702 | return -1; |
| 703 | }); |
| 704 | |
| 705 | if (!fmc->head) { |
| 706 | /* The flash memory is totally empty. No nodes. No dirt. |
| 707 | Just return. */ |
| 708 | return 0; |
| 709 | } |
| 710 | |
| 711 | /* Calculate how much space that is dirty. */ |
| 712 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next) { |
| 713 | if (size && fm->offset == 0) { |
| 714 | /* We have reached the beginning of the flash. */ |
| 715 | break; |
| 716 | } |
| 717 | size += fm->size; |
| 718 | } |
| 719 | |
| 720 | /* Someone's signature contained this: |
| 721 | There's a fine line between fishing and just standing on |
| 722 | the shore like an idiot... */ |
| 723 | ret = jffs_flash_erasable_size(fmc->mtd, fmc->head->offset, size); |
| 724 | |
| 725 | ASSERT(if (ret < 0) { |
| 726 | printk("jffs_erasable_size: flash_erasable_size() " |
| 727 | "returned something less than zero (%ld).\n", ret); |
| 728 | printk("jffs_erasable_size: offset = 0x%08x\n", |
| 729 | fmc->head->offset); |
| 730 | }); |
| 731 | |
| 732 | /* If there is dirt on the flash (which is the reason to why |
| 733 | this function was called in the first place) but no space is |
| 734 | possible to erase right now, the initial part of the list of |
| 735 | jffs_fm structs, that hold place for dirty space, could perhaps |
| 736 | be shortened. The list's initial "dirty" elements are merged |
| 737 | into just one large dirty jffs_fm struct. This operation must |
| 738 | only be performed if nothing is possible to erase. Otherwise, |
| 739 | jffs_clear_end_of_node() won't work as expected. */ |
| 740 | if (ret == 0) { |
| 741 | struct jffs_fm *head = fmc->head; |
| 742 | struct jffs_fm *del; |
| 743 | /* While there are two dirty nodes beside each other.*/ |
| 744 | while (head->nodes == 0 |
| 745 | && head->next |
| 746 | && head->next->nodes == 0) { |
| 747 | del = head->next; |
| 748 | head->size += del->size; |
| 749 | head->next = del->next; |
| 750 | if (del->next) { |
| 751 | del->next->prev = head; |
| 752 | } |
| 753 | jffs_free_fm(del); |
| 754 | } |
| 755 | } |
| 756 | |
| 757 | return (ret >= 0 ? ret : 0); |
| 758 | } |
| 759 | |
| 760 | static struct jffs_fm *jffs_alloc_fm(void) |
| 761 | { |
| 762 | struct jffs_fm *fm; |
| 763 | |
| 764 | fm = kmem_cache_alloc(fm_cache,GFP_KERNEL); |
| 765 | DJM(if (fm) no_jffs_fm++;); |
| 766 | |
| 767 | return fm; |
| 768 | } |
| 769 | |
| 770 | static void jffs_free_fm(struct jffs_fm *n) |
| 771 | { |
| 772 | kmem_cache_free(fm_cache,n); |
| 773 | DJM(no_jffs_fm--); |
| 774 | } |
| 775 | |
| 776 | |
| 777 | |
| 778 | struct jffs_node *jffs_alloc_node(void) |
| 779 | { |
| 780 | struct jffs_node *n; |
| 781 | |
| 782 | n = (struct jffs_node *)kmem_cache_alloc(node_cache,GFP_KERNEL); |
| 783 | if(n != NULL) |
| 784 | no_jffs_node++; |
| 785 | return n; |
| 786 | } |
| 787 | |
| 788 | void jffs_free_node(struct jffs_node *n) |
| 789 | { |
| 790 | kmem_cache_free(node_cache,n); |
| 791 | no_jffs_node--; |
| 792 | } |
| 793 | |
| 794 | |
| 795 | int jffs_get_node_inuse(void) |
| 796 | { |
| 797 | return no_jffs_node; |
| 798 | } |