1 /* 2 * Copyright (c) International Business Machines Corp., 2006 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 12 * the GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * Author: Artem Bityutskiy (Битюцкий Артём) 19 */ 20 21 /* This file mostly implements UBI kernel API functions */ 22 23 #include <linux/module.h> 24 #include <linux/err.h> 25 #include <asm/div64.h> 26 #include "ubi.h" 27 28 /** 29 * ubi_get_device_info - get information about UBI device. 30 * @ubi_num: UBI device number 31 * @di: the information is stored here 32 * 33 * This function returns %0 in case of success, %-EINVAL if the UBI device 34 * number is invalid, and %-ENODEV if there is no such UBI device. 35 */ 36 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) 37 { 38 struct ubi_device *ubi; 39 40 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) 41 return -EINVAL; 42 43 ubi = ubi_get_device(ubi_num); 44 if (!ubi) 45 return -ENODEV; 46 47 di->ubi_num = ubi->ubi_num; 48 di->leb_size = ubi->leb_size; 49 di->min_io_size = ubi->min_io_size; 50 di->ro_mode = ubi->ro_mode; 51 di->cdev = ubi->cdev.dev; 52 53 ubi_put_device(ubi); 54 return 0; 55 } 56 EXPORT_SYMBOL_GPL(ubi_get_device_info); 57 58 /** 59 * ubi_get_volume_info - get information about UBI volume. 60 * @desc: volume descriptor 61 * @vi: the information is stored here 62 */ 63 void ubi_get_volume_info(struct ubi_volume_desc *desc, 64 struct ubi_volume_info *vi) 65 { 66 const struct ubi_volume *vol = desc->vol; 67 const struct ubi_device *ubi = vol->ubi; 68 69 vi->vol_id = vol->vol_id; 70 vi->ubi_num = ubi->ubi_num; 71 vi->size = vol->reserved_pebs; 72 vi->used_bytes = vol->used_bytes; 73 vi->vol_type = vol->vol_type; 74 vi->corrupted = vol->corrupted; 75 vi->upd_marker = vol->upd_marker; 76 vi->alignment = vol->alignment; 77 vi->usable_leb_size = vol->usable_leb_size; 78 vi->name_len = vol->name_len; 79 vi->name = vol->name; 80 vi->cdev = vol->cdev.dev; 81 } 82 EXPORT_SYMBOL_GPL(ubi_get_volume_info); 83 84 /** 85 * ubi_open_volume - open UBI volume. 86 * @ubi_num: UBI device number 87 * @vol_id: volume ID 88 * @mode: open mode 89 * 90 * The @mode parameter specifies if the volume should be opened in read-only 91 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that 92 * nobody else will be able to open this volume. UBI allows to have many volume 93 * readers and one writer at a time. 94 * 95 * If a static volume is being opened for the first time since boot, it will be 96 * checked by this function, which means it will be fully read and the CRC 97 * checksum of each logical eraseblock will be checked. 98 * 99 * This function returns volume descriptor in case of success and a negative 100 * error code in case of failure. 101 */ 102 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) 103 { 104 int err; 105 struct ubi_volume_desc *desc; 106 struct ubi_device *ubi; 107 struct ubi_volume *vol; 108 109 dbg_gen("open device %d volume %d, mode %d", ubi_num, vol_id, mode); 110 111 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) 112 return ERR_PTR(-EINVAL); 113 114 if (mode != UBI_READONLY && mode != UBI_READWRITE && 115 mode != UBI_EXCLUSIVE) 116 return ERR_PTR(-EINVAL); 117 118 /* 119 * First of all, we have to get the UBI device to prevent its removal. 120 */ 121 ubi = ubi_get_device(ubi_num); 122 if (!ubi) 123 return ERR_PTR(-ENODEV); 124 125 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) { 126 err = -EINVAL; 127 goto out_put_ubi; 128 } 129 130 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); 131 if (!desc) { 132 err = -ENOMEM; 133 goto out_put_ubi; 134 } 135 136 err = -ENODEV; 137 if (!try_module_get(THIS_MODULE)) 138 goto out_free; 139 140 spin_lock(&ubi->volumes_lock); 141 vol = ubi->volumes[vol_id]; 142 if (!vol) 143 goto out_unlock; 144 145 err = -EBUSY; 146 switch (mode) { 147 case UBI_READONLY: 148 if (vol->exclusive) 149 goto out_unlock; 150 vol->readers += 1; 151 break; 152 153 case UBI_READWRITE: 154 if (vol->exclusive || vol->writers > 0) 155 goto out_unlock; 156 vol->writers += 1; 157 break; 158 159 case UBI_EXCLUSIVE: 160 if (vol->exclusive || vol->writers || vol->readers) 161 goto out_unlock; 162 vol->exclusive = 1; 163 break; 164 } 165 get_device(&vol->dev); 166 vol->ref_count += 1; 167 spin_unlock(&ubi->volumes_lock); 168 169 desc->vol = vol; 170 desc->mode = mode; 171 172 mutex_lock(&ubi->ckvol_mutex); 173 if (!vol->checked) { 174 /* This is the first open - check the volume */ 175 err = ubi_check_volume(ubi, vol_id); 176 if (err < 0) { 177 mutex_unlock(&ubi->ckvol_mutex); 178 ubi_close_volume(desc); 179 return ERR_PTR(err); 180 } 181 if (err == 1) { 182 ubi_warn("volume %d on UBI device %d is corrupted", 183 vol_id, ubi->ubi_num); 184 vol->corrupted = 1; 185 } 186 vol->checked = 1; 187 } 188 mutex_unlock(&ubi->ckvol_mutex); 189 190 return desc; 191 192 out_unlock: 193 spin_unlock(&ubi->volumes_lock); 194 module_put(THIS_MODULE); 195 out_free: 196 kfree(desc); 197 out_put_ubi: 198 ubi_put_device(ubi); 199 return ERR_PTR(err); 200 } 201 EXPORT_SYMBOL_GPL(ubi_open_volume); 202 203 /** 204 * ubi_open_volume_nm - open UBI volume by name. 205 * @ubi_num: UBI device number 206 * @name: volume name 207 * @mode: open mode 208 * 209 * This function is similar to 'ubi_open_volume()', but opens a volume by name. 210 */ 211 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 212 int mode) 213 { 214 int i, vol_id = -1, len; 215 struct ubi_device *ubi; 216 struct ubi_volume_desc *ret; 217 218 dbg_gen("open volume %s, mode %d", name, mode); 219 220 if (!name) 221 return ERR_PTR(-EINVAL); 222 223 len = strnlen(name, UBI_VOL_NAME_MAX + 1); 224 if (len > UBI_VOL_NAME_MAX) 225 return ERR_PTR(-EINVAL); 226 227 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) 228 return ERR_PTR(-EINVAL); 229 230 ubi = ubi_get_device(ubi_num); 231 if (!ubi) 232 return ERR_PTR(-ENODEV); 233 234 spin_lock(&ubi->volumes_lock); 235 /* Walk all volumes of this UBI device */ 236 for (i = 0; i < ubi->vtbl_slots; i++) { 237 struct ubi_volume *vol = ubi->volumes[i]; 238 239 if (vol && len == vol->name_len && !strcmp(name, vol->name)) { 240 vol_id = i; 241 break; 242 } 243 } 244 spin_unlock(&ubi->volumes_lock); 245 246 if (vol_id >= 0) 247 ret = ubi_open_volume(ubi_num, vol_id, mode); 248 else 249 ret = ERR_PTR(-ENODEV); 250 251 /* 252 * We should put the UBI device even in case of success, because 253 * 'ubi_open_volume()' took a reference as well. 254 */ 255 ubi_put_device(ubi); 256 return ret; 257 } 258 EXPORT_SYMBOL_GPL(ubi_open_volume_nm); 259 260 /** 261 * ubi_close_volume - close UBI volume. 262 * @desc: volume descriptor 263 */ 264 void ubi_close_volume(struct ubi_volume_desc *desc) 265 { 266 struct ubi_volume *vol = desc->vol; 267 struct ubi_device *ubi = vol->ubi; 268 269 dbg_gen("close volume %d, mode %d", vol->vol_id, desc->mode); 270 271 spin_lock(&ubi->volumes_lock); 272 switch (desc->mode) { 273 case UBI_READONLY: 274 vol->readers -= 1; 275 break; 276 case UBI_READWRITE: 277 vol->writers -= 1; 278 break; 279 case UBI_EXCLUSIVE: 280 vol->exclusive = 0; 281 } 282 vol->ref_count -= 1; 283 spin_unlock(&ubi->volumes_lock); 284 285 kfree(desc); 286 put_device(&vol->dev); 287 ubi_put_device(ubi); 288 module_put(THIS_MODULE); 289 } 290 EXPORT_SYMBOL_GPL(ubi_close_volume); 291 292 /** 293 * ubi_leb_read - read data. 294 * @desc: volume descriptor 295 * @lnum: logical eraseblock number to read from 296 * @buf: buffer where to store the read data 297 * @offset: offset within the logical eraseblock to read from 298 * @len: how many bytes to read 299 * @check: whether UBI has to check the read data's CRC or not. 300 * 301 * This function reads data from offset @offset of logical eraseblock @lnum and 302 * stores the data at @buf. When reading from static volumes, @check specifies 303 * whether the data has to be checked or not. If yes, the whole logical 304 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC 305 * checksum is per-eraseblock). So checking may substantially slow down the 306 * read speed. The @check argument is ignored for dynamic volumes. 307 * 308 * In case of success, this function returns zero. In case of failure, this 309 * function returns a negative error code. 310 * 311 * %-EBADMSG error code is returned: 312 * o for both static and dynamic volumes if MTD driver has detected a data 313 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND); 314 * o for static volumes in case of data CRC mismatch. 315 * 316 * If the volume is damaged because of an interrupted update this function just 317 * returns immediately with %-EBADF error code. 318 */ 319 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 320 int len, int check) 321 { 322 struct ubi_volume *vol = desc->vol; 323 struct ubi_device *ubi = vol->ubi; 324 int err, vol_id = vol->vol_id; 325 326 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); 327 328 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 || 329 lnum >= vol->used_ebs || offset < 0 || len < 0 || 330 offset + len > vol->usable_leb_size) 331 return -EINVAL; 332 333 if (vol->vol_type == UBI_STATIC_VOLUME) { 334 if (vol->used_ebs == 0) 335 /* Empty static UBI volume */ 336 return 0; 337 if (lnum == vol->used_ebs - 1 && 338 offset + len > vol->last_eb_bytes) 339 return -EINVAL; 340 } 341 342 if (vol->upd_marker) 343 return -EBADF; 344 if (len == 0) 345 return 0; 346 347 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check); 348 if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) { 349 ubi_warn("mark volume %d as corrupted", vol_id); 350 vol->corrupted = 1; 351 } 352 353 return err; 354 } 355 EXPORT_SYMBOL_GPL(ubi_leb_read); 356 357 /** 358 * ubi_leb_write - write data. 359 * @desc: volume descriptor 360 * @lnum: logical eraseblock number to write to 361 * @buf: data to write 362 * @offset: offset within the logical eraseblock where to write 363 * @len: how many bytes to write 364 * @dtype: expected data type 365 * 366 * This function writes @len bytes of data from @buf to offset @offset of 367 * logical eraseblock @lnum. The @dtype argument describes expected lifetime of 368 * the data. 369 * 370 * This function takes care of physical eraseblock write failures. If write to 371 * the physical eraseblock write operation fails, the logical eraseblock is 372 * re-mapped to another physical eraseblock, the data is recovered, and the 373 * write finishes. UBI has a pool of reserved physical eraseblocks for this. 374 * 375 * If all the data were successfully written, zero is returned. If an error 376 * occurred and UBI has not been able to recover from it, this function returns 377 * a negative error code. Note, in case of an error, it is possible that 378 * something was still written to the flash media, but that may be some 379 * garbage. 380 * 381 * If the volume is damaged because of an interrupted update this function just 382 * returns immediately with %-EBADF code. 383 */ 384 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 385 int offset, int len, int dtype) 386 { 387 struct ubi_volume *vol = desc->vol; 388 struct ubi_device *ubi = vol->ubi; 389 int vol_id = vol->vol_id; 390 391 dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset); 392 393 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) 394 return -EINVAL; 395 396 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) 397 return -EROFS; 398 399 if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || 400 offset + len > vol->usable_leb_size || 401 offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1)) 402 return -EINVAL; 403 404 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && 405 dtype != UBI_UNKNOWN) 406 return -EINVAL; 407 408 if (vol->upd_marker) 409 return -EBADF; 410 411 if (len == 0) 412 return 0; 413 414 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype); 415 } 416 EXPORT_SYMBOL_GPL(ubi_leb_write); 417 418 /* 419 * ubi_leb_change - change logical eraseblock atomically. 420 * @desc: volume descriptor 421 * @lnum: logical eraseblock number to change 422 * @buf: data to write 423 * @len: how many bytes to write 424 * @dtype: expected data type 425 * 426 * This function changes the contents of a logical eraseblock atomically. @buf 427 * has to contain new logical eraseblock data, and @len - the length of the 428 * data, which has to be aligned. The length may be shorter then the logical 429 * eraseblock size, ant the logical eraseblock may be appended to more times 430 * later on. This function guarantees that in case of an unclean reboot the old 431 * contents is preserved. Returns zero in case of success and a negative error 432 * code in case of failure. 433 */ 434 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 435 int len, int dtype) 436 { 437 struct ubi_volume *vol = desc->vol; 438 struct ubi_device *ubi = vol->ubi; 439 int vol_id = vol->vol_id; 440 441 dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum); 442 443 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) 444 return -EINVAL; 445 446 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) 447 return -EROFS; 448 449 if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || 450 len > vol->usable_leb_size || len & (ubi->min_io_size - 1)) 451 return -EINVAL; 452 453 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && 454 dtype != UBI_UNKNOWN) 455 return -EINVAL; 456 457 if (vol->upd_marker) 458 return -EBADF; 459 460 if (len == 0) 461 return 0; 462 463 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype); 464 } 465 EXPORT_SYMBOL_GPL(ubi_leb_change); 466 467 /** 468 * ubi_leb_erase - erase logical eraseblock. 469 * @desc: volume descriptor 470 * @lnum: logical eraseblock number 471 * 472 * This function un-maps logical eraseblock @lnum and synchronously erases the 473 * correspondent physical eraseblock. Returns zero in case of success and a 474 * negative error code in case of failure. 475 * 476 * If the volume is damaged because of an interrupted update this function just 477 * returns immediately with %-EBADF code. 478 */ 479 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum) 480 { 481 struct ubi_volume *vol = desc->vol; 482 struct ubi_device *ubi = vol->ubi; 483 int err; 484 485 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum); 486 487 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) 488 return -EROFS; 489 490 if (lnum < 0 || lnum >= vol->reserved_pebs) 491 return -EINVAL; 492 493 if (vol->upd_marker) 494 return -EBADF; 495 496 err = ubi_eba_unmap_leb(ubi, vol, lnum); 497 if (err) 498 return err; 499 500 return ubi_wl_flush(ubi); 501 } 502 EXPORT_SYMBOL_GPL(ubi_leb_erase); 503 504 /** 505 * ubi_leb_unmap - un-map logical eraseblock. 506 * @desc: volume descriptor 507 * @lnum: logical eraseblock number 508 * 509 * This function un-maps logical eraseblock @lnum and schedules the 510 * corresponding physical eraseblock for erasure, so that it will eventually be 511 * physically erased in background. This operation is much faster then the 512 * erase operation. 513 * 514 * Unlike erase, the un-map operation does not guarantee that the logical 515 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For 516 * example, if several logical eraseblocks are un-mapped, and an unclean reboot 517 * happens after this, the logical eraseblocks will not necessarily be 518 * un-mapped again when this MTD device is attached. They may actually be 519 * mapped to the same physical eraseblocks again. So, this function has to be 520 * used with care. 521 * 522 * In other words, when un-mapping a logical eraseblock, UBI does not store 523 * any information about this on the flash media, it just marks the logical 524 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical 525 * eraseblock is physically erased, it will be mapped again to the same logical 526 * eraseblock when the MTD device is attached again. 527 * 528 * The main and obvious use-case of this function is when the contents of a 529 * logical eraseblock has to be re-written. Then it is much more efficient to 530 * first un-map it, then write new data, rather then first erase it, then write 531 * new data. Note, once new data has been written to the logical eraseblock, 532 * UBI guarantees that the old contents has gone forever. In other words, if an 533 * unclean reboot happens after the logical eraseblock has been un-mapped and 534 * then written to, it will contain the last written data. 535 * 536 * This function returns zero in case of success and a negative error code in 537 * case of failure. If the volume is damaged because of an interrupted update 538 * this function just returns immediately with %-EBADF code. 539 */ 540 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) 541 { 542 struct ubi_volume *vol = desc->vol; 543 struct ubi_device *ubi = vol->ubi; 544 545 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum); 546 547 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) 548 return -EROFS; 549 550 if (lnum < 0 || lnum >= vol->reserved_pebs) 551 return -EINVAL; 552 553 if (vol->upd_marker) 554 return -EBADF; 555 556 return ubi_eba_unmap_leb(ubi, vol, lnum); 557 } 558 EXPORT_SYMBOL_GPL(ubi_leb_unmap); 559 560 /** 561 * ubi_leb_map - map logical erasblock to a physical eraseblock. 562 * @desc: volume descriptor 563 * @lnum: logical eraseblock number 564 * @dtype: expected data type 565 * 566 * This function maps an un-mapped logical eraseblock @lnum to a physical 567 * eraseblock. This means, that after a successful invocation of this 568 * function the logical eraseblock @lnum will be empty (contain only %0xFF 569 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot 570 * happens. 571 * 572 * This function returns zero in case of success, %-EBADF if the volume is 573 * damaged because of an interrupted update, %-EBADMSG if the logical 574 * eraseblock is already mapped, and other negative error codes in case of 575 * other failures. 576 */ 577 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype) 578 { 579 struct ubi_volume *vol = desc->vol; 580 struct ubi_device *ubi = vol->ubi; 581 582 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum); 583 584 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) 585 return -EROFS; 586 587 if (lnum < 0 || lnum >= vol->reserved_pebs) 588 return -EINVAL; 589 590 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && 591 dtype != UBI_UNKNOWN) 592 return -EINVAL; 593 594 if (vol->upd_marker) 595 return -EBADF; 596 597 if (vol->eba_tbl[lnum] >= 0) 598 return -EBADMSG; 599 600 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype); 601 } 602 EXPORT_SYMBOL_GPL(ubi_leb_map); 603 604 /** 605 * ubi_is_mapped - check if logical eraseblock is mapped. 606 * @desc: volume descriptor 607 * @lnum: logical eraseblock number 608 * 609 * This function checks if logical eraseblock @lnum is mapped to a physical 610 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily 611 * mean it will still be un-mapped after the UBI device is re-attached. The 612 * logical eraseblock may become mapped to the physical eraseblock it was last 613 * mapped to. 614 * 615 * This function returns %1 if the LEB is mapped, %0 if not, and a negative 616 * error code in case of failure. If the volume is damaged because of an 617 * interrupted update this function just returns immediately with %-EBADF error 618 * code. 619 */ 620 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum) 621 { 622 struct ubi_volume *vol = desc->vol; 623 624 dbg_gen("test LEB %d:%d", vol->vol_id, lnum); 625 626 if (lnum < 0 || lnum >= vol->reserved_pebs) 627 return -EINVAL; 628 629 if (vol->upd_marker) 630 return -EBADF; 631 632 return vol->eba_tbl[lnum] >= 0; 633 } 634 EXPORT_SYMBOL_GPL(ubi_is_mapped); 635 636 /** 637 * ubi_sync - synchronize UBI device buffers. 638 * @ubi_num: UBI device to synchronize 639 * 640 * The underlying MTD device may cache data in hardware or in software. This 641 * function ensures the caches are flushed. Returns zero in case of success and 642 * a negative error code in case of failure. 643 */ 644 int ubi_sync(int ubi_num) 645 { 646 struct ubi_device *ubi; 647 648 ubi = ubi_get_device(ubi_num); 649 if (!ubi) 650 return -ENODEV; 651 652 if (ubi->mtd->sync) 653 ubi->mtd->sync(ubi->mtd); 654 655 ubi_put_device(ubi); 656 return 0; 657 } 658 EXPORT_SYMBOL_GPL(ubi_sync); 659