drivers/mtd/ubi/block.c

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This source file includes following definitions.
ubiblock_set_param
find_dev_nolock
ubiblock_read
ubiblock_open
ubiblock_release
ubiblock_getgeo
ubiblock_do_work
ubiblock_queue_rq
ubiblock_init_request
calc_disk_capacity
ubiblock_create
ubiblock_cleanup
ubiblock_remove
ubiblock_resize
ubiblock_notify
open_volume_desc
ubiblock_create_from_param
ubiblock_remove_all
ubiblock_init
ubiblock_exit
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2014 Ezequiel Garcia
   4  * Copyright (c) 2011 Free Electrons
   5  *
   6  * Driver parameter handling strongly based on drivers/mtd/ubi/build.c
   7  *   Copyright (c) International Business Machines Corp., 2006
   8  *   Copyright (c) Nokia Corporation, 2007
   9  *   Authors: Artem Bityutskiy, Frank Haverkamp
  10  */
  11 
  12 /*
  13  * Read-only block devices on top of UBI volumes
  14  *
  15  * A simple implementation to allow a block device to be layered on top of a
  16  * UBI volume. The implementation is provided by creating a static 1-to-1
  17  * mapping between the block device and the UBI volume.
  18  *
  19  * The addressed byte is obtained from the addressed block sector, which is
  20  * mapped linearly into the corresponding LEB:
  21  *
  22  *   LEB number = addressed byte / LEB size
  23  *
  24  * This feature is compiled in the UBI core, and adds a 'block' parameter
  25  * to allow early creation of block devices on top of UBI volumes. Runtime
  26  * block creation/removal for UBI volumes is provided through two UBI ioctls:
  27  * UBI_IOCVOLCRBLK and UBI_IOCVOLRMBLK.
  28  */
  29 
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/err.h>
  33 #include <linux/kernel.h>
  34 #include <linux/list.h>
  35 #include <linux/mutex.h>
  36 #include <linux/slab.h>
  37 #include <linux/mtd/ubi.h>
  38 #include <linux/workqueue.h>
  39 #include <linux/blkdev.h>
  40 #include <linux/blk-mq.h>
  41 #include <linux/hdreg.h>
  42 #include <linux/scatterlist.h>
  43 #include <linux/idr.h>
  44 #include <asm/div64.h>
  45 
  46 #include "ubi-media.h"
  47 #include "ubi.h"
  48 
  49 /* Maximum number of supported devices */
  50 #define UBIBLOCK_MAX_DEVICES 32
  51 
  52 /* Maximum length of the 'block=' parameter */
  53 #define UBIBLOCK_PARAM_LEN 63
  54 
  55 /* Maximum number of comma-separated items in the 'block=' parameter */
  56 #define UBIBLOCK_PARAM_COUNT 2
  57 
  58 struct ubiblock_param {
  59         int ubi_num;
  60         int vol_id;
  61         char name[UBIBLOCK_PARAM_LEN+1];
  62 };
  63 
  64 struct ubiblock_pdu {
  65         struct work_struct work;
  66         struct ubi_sgl usgl;
  67 };
  68 
  69 /* Numbers of elements set in the @ubiblock_param array */
  70 static int ubiblock_devs __initdata;
  71 
  72 /* MTD devices specification parameters */
  73 static struct ubiblock_param ubiblock_param[UBIBLOCK_MAX_DEVICES] __initdata;
  74 
  75 struct ubiblock {
  76         struct ubi_volume_desc *desc;
  77         int ubi_num;
  78         int vol_id;
  79         int refcnt;
  80         int leb_size;
  81 
  82         struct gendisk *gd;
  83         struct request_queue *rq;
  84 
  85         struct workqueue_struct *wq;
  86 
  87         struct mutex dev_mutex;
  88         struct list_head list;
  89         struct blk_mq_tag_set tag_set;
  90 };
  91 
  92 /* Linked list of all ubiblock instances */
  93 static LIST_HEAD(ubiblock_devices);
  94 static DEFINE_IDR(ubiblock_minor_idr);
  95 /* Protects ubiblock_devices and ubiblock_minor_idr */
  96 static DEFINE_MUTEX(devices_mutex);
  97 static int ubiblock_major;
  98 
  99 static int __init ubiblock_set_param(const char *val,
 100                                      const struct kernel_param *kp)
 101 {
 102         int i, ret;
 103         size_t len;
 104         struct ubiblock_param *param;
 105         char buf[UBIBLOCK_PARAM_LEN];
 106         char *pbuf = &buf[0];
 107         char *tokens[UBIBLOCK_PARAM_COUNT];
 108 
 109         if (!val)
 110                 return -EINVAL;
 111 
 112         len = strnlen(val, UBIBLOCK_PARAM_LEN);
 113         if (len == 0) {
 114                 pr_warn("UBI: block: empty 'block=' parameter - ignored\n");
 115                 return 0;
 116         }
 117 
 118         if (len == UBIBLOCK_PARAM_LEN) {
 119                 pr_err("UBI: block: parameter \"%s\" is too long, max. is %d\n",
 120                        val, UBIBLOCK_PARAM_LEN);
 121                 return -EINVAL;
 122         }
 123 
 124         strcpy(buf, val);
 125 
 126         /* Get rid of the final newline */
 127         if (buf[len - 1] == '\n')
 128                 buf[len - 1] = '\0';
 129 
 130         for (i = 0; i < UBIBLOCK_PARAM_COUNT; i++)
 131                 tokens[i] = strsep(&pbuf, ",");
 132 
 133         param = &ubiblock_param[ubiblock_devs];
 134         if (tokens[1]) {
 135                 /* Two parameters: can be 'ubi, vol_id' or 'ubi, vol_name' */
 136                 ret = kstrtoint(tokens[0], 10, &param->ubi_num);
 137                 if (ret < 0)
 138                         return -EINVAL;
 139 
 140                 /* Second param can be a number or a name */
 141                 ret = kstrtoint(tokens[1], 10, &param->vol_id);
 142                 if (ret < 0) {
 143                         param->vol_id = -1;
 144                         strcpy(param->name, tokens[1]);
 145                 }
 146 
 147         } else {
 148                 /* One parameter: must be device path */
 149                 strcpy(param->name, tokens[0]);
 150                 param->ubi_num = -1;
 151                 param->vol_id = -1;
 152         }
 153 
 154         ubiblock_devs++;
 155 
 156         return 0;
 157 }
 158 
 159 static const struct kernel_param_ops ubiblock_param_ops = {
 160         .set    = ubiblock_set_param,
 161 };
 162 module_param_cb(block, &ubiblock_param_ops, NULL, 0);
 163 MODULE_PARM_DESC(block, "Attach block devices to UBI volumes. Parameter format: block=<path|dev,num|dev,name>.\n"
 164                         "Multiple \"block\" parameters may be specified.\n"
 165                         "UBI volumes may be specified by their number, name, or path to the device node.\n"
 166                         "Examples\n"
 167                         "Using the UBI volume path:\n"
 168                         "ubi.block=/dev/ubi0_0\n"
 169                         "Using the UBI device, and the volume name:\n"
 170                         "ubi.block=0,rootfs\n"
 171                         "Using both UBI device number and UBI volume number:\n"
 172                         "ubi.block=0,0\n");
 173 
 174 static struct ubiblock *find_dev_nolock(int ubi_num, int vol_id)
 175 {
 176         struct ubiblock *dev;
 177 
 178         list_for_each_entry(dev, &ubiblock_devices, list)
 179                 if (dev->ubi_num == ubi_num && dev->vol_id == vol_id)
 180                         return dev;
 181         return NULL;
 182 }
 183 
 184 static int ubiblock_read(struct ubiblock_pdu *pdu)
 185 {
 186         int ret, leb, offset, bytes_left, to_read;
 187         u64 pos;
 188         struct request *req = blk_mq_rq_from_pdu(pdu);
 189         struct ubiblock *dev = req->q->queuedata;
 190 
 191         to_read = blk_rq_bytes(req);
 192         pos = blk_rq_pos(req) << 9;
 193 
 194         /* Get LEB:offset address to read from */
 195         offset = do_div(pos, dev->leb_size);
 196         leb = pos;
 197         bytes_left = to_read;
 198 
 199         while (bytes_left) {
 200                 /*
 201                  * We can only read one LEB at a time. Therefore if the read
 202                  * length is larger than one LEB size, we split the operation.
 203                  */
 204                 if (offset + to_read > dev->leb_size)
 205                         to_read = dev->leb_size - offset;
 206 
 207                 ret = ubi_read_sg(dev->desc, leb, &pdu->usgl, offset, to_read);
 208                 if (ret < 0)
 209                         return ret;
 210 
 211                 bytes_left -= to_read;
 212                 to_read = bytes_left;
 213                 leb += 1;
 214                 offset = 0;
 215         }
 216         return 0;
 217 }
 218 
 219 static int ubiblock_open(struct block_device *bdev, fmode_t mode)
 220 {
 221         struct ubiblock *dev = bdev->bd_disk->private_data;
 222         int ret;
 223 
 224         mutex_lock(&dev->dev_mutex);
 225         if (dev->refcnt > 0) {
 226                 /*
 227                  * The volume is already open, just increase the reference
 228                  * counter.
 229                  */
 230                 goto out_done;
 231         }
 232 
 233         /*
 234          * We want users to be aware they should only mount us as read-only.
 235          * It's just a paranoid check, as write requests will get rejected
 236          * in any case.
 237          */
 238         if (mode & FMODE_WRITE) {
 239                 ret = -EROFS;
 240                 goto out_unlock;
 241         }
 242 
 243         dev->desc = ubi_open_volume(dev->ubi_num, dev->vol_id, UBI_READONLY);
 244         if (IS_ERR(dev->desc)) {
 245                 dev_err(disk_to_dev(dev->gd), "failed to open ubi volume %d_%d",
 246                         dev->ubi_num, dev->vol_id);
 247                 ret = PTR_ERR(dev->desc);
 248                 dev->desc = NULL;
 249                 goto out_unlock;
 250         }
 251 
 252 out_done:
 253         dev->refcnt++;
 254         mutex_unlock(&dev->dev_mutex);
 255         return 0;
 256 
 257 out_unlock:
 258         mutex_unlock(&dev->dev_mutex);
 259         return ret;
 260 }
 261 
 262 static void ubiblock_release(struct gendisk *gd, fmode_t mode)
 263 {
 264         struct ubiblock *dev = gd->private_data;
 265 
 266         mutex_lock(&dev->dev_mutex);
 267         dev->refcnt--;
 268         if (dev->refcnt == 0) {
 269                 ubi_close_volume(dev->desc);
 270                 dev->desc = NULL;
 271         }
 272         mutex_unlock(&dev->dev_mutex);
 273 }
 274 
 275 static int ubiblock_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 276 {
 277         /* Some tools might require this information */
 278         geo->heads = 1;
 279         geo->cylinders = 1;
 280         geo->sectors = get_capacity(bdev->bd_disk);
 281         geo->start = 0;
 282         return 0;
 283 }
 284 
 285 static const struct block_device_operations ubiblock_ops = {
 286         .owner = THIS_MODULE,
 287         .open = ubiblock_open,
 288         .release = ubiblock_release,
 289         .getgeo = ubiblock_getgeo,
 290 };
 291 
 292 static void ubiblock_do_work(struct work_struct *work)
 293 {
 294         int ret;
 295         struct ubiblock_pdu *pdu = container_of(work, struct ubiblock_pdu, work);
 296         struct request *req = blk_mq_rq_from_pdu(pdu);
 297 
 298         blk_mq_start_request(req);
 299 
 300         /*
 301          * It is safe to ignore the return value of blk_rq_map_sg() because
 302          * the number of sg entries is limited to UBI_MAX_SG_COUNT
 303          * and ubi_read_sg() will check that limit.
 304          */
 305         blk_rq_map_sg(req->q, req, pdu->usgl.sg);
 306 
 307         ret = ubiblock_read(pdu);
 308         rq_flush_dcache_pages(req);
 309 
 310         blk_mq_end_request(req, errno_to_blk_status(ret));
 311 }
 312 
 313 static blk_status_t ubiblock_queue_rq(struct blk_mq_hw_ctx *hctx,
 314                              const struct blk_mq_queue_data *bd)
 315 {
 316         struct request *req = bd->rq;
 317         struct ubiblock *dev = hctx->queue->queuedata;
 318         struct ubiblock_pdu *pdu = blk_mq_rq_to_pdu(req);
 319 
 320         switch (req_op(req)) {
 321         case REQ_OP_READ:
 322                 ubi_sgl_init(&pdu->usgl);
 323                 queue_work(dev->wq, &pdu->work);
 324                 return BLK_STS_OK;
 325         default:
 326                 return BLK_STS_IOERR;
 327         }
 328 
 329 }
 330 
 331 static int ubiblock_init_request(struct blk_mq_tag_set *set,
 332                 struct request *req, unsigned int hctx_idx,
 333                 unsigned int numa_node)
 334 {
 335         struct ubiblock_pdu *pdu = blk_mq_rq_to_pdu(req);
 336 
 337         sg_init_table(pdu->usgl.sg, UBI_MAX_SG_COUNT);
 338         INIT_WORK(&pdu->work, ubiblock_do_work);
 339 
 340         return 0;
 341 }
 342 
 343 static const struct blk_mq_ops ubiblock_mq_ops = {
 344         .queue_rq       = ubiblock_queue_rq,
 345         .init_request   = ubiblock_init_request,
 346 };
 347 
 348 static int calc_disk_capacity(struct ubi_volume_info *vi, u64 *disk_capacity)
 349 {
 350         u64 size = vi->used_bytes >> 9;
 351 
 352         if (vi->used_bytes % 512) {
 353                 pr_warn("UBI: block: volume size is not a multiple of 512, "
 354                         "last %llu bytes are ignored!\n",
 355                         vi->used_bytes - (size << 9));
 356         }
 357 
 358         if ((sector_t)size != size)
 359                 return -EFBIG;
 360 
 361         *disk_capacity = size;
 362 
 363         return 0;
 364 }
 365 
 366 int ubiblock_create(struct ubi_volume_info *vi)
 367 {
 368         struct ubiblock *dev;
 369         struct gendisk *gd;
 370         u64 disk_capacity;
 371         int ret;
 372 
 373         ret = calc_disk_capacity(vi, &disk_capacity);
 374         if (ret) {
 375                 return ret;
 376         }
 377 
 378         /* Check that the volume isn't already handled */
 379         mutex_lock(&devices_mutex);
 380         if (find_dev_nolock(vi->ubi_num, vi->vol_id)) {
 381                 ret = -EEXIST;
 382                 goto out_unlock;
 383         }
 384 
 385         dev = kzalloc(sizeof(struct ubiblock), GFP_KERNEL);
 386         if (!dev) {
 387                 ret = -ENOMEM;
 388                 goto out_unlock;
 389         }
 390 
 391         mutex_init(&dev->dev_mutex);
 392 
 393         dev->ubi_num = vi->ubi_num;
 394         dev->vol_id = vi->vol_id;
 395         dev->leb_size = vi->usable_leb_size;
 396 
 397         /* Initialize the gendisk of this ubiblock device */
 398         gd = alloc_disk(1);
 399         if (!gd) {
 400                 pr_err("UBI: block: alloc_disk failed\n");
 401                 ret = -ENODEV;
 402                 goto out_free_dev;
 403         }
 404 
 405         gd->fops = &ubiblock_ops;
 406         gd->major = ubiblock_major;
 407         gd->first_minor = idr_alloc(&ubiblock_minor_idr, dev, 0, 0, GFP_KERNEL);
 408         if (gd->first_minor < 0) {
 409                 dev_err(disk_to_dev(gd),
 410                         "block: dynamic minor allocation failed");
 411                 ret = -ENODEV;
 412                 goto out_put_disk;
 413         }
 414         gd->private_data = dev;
 415         sprintf(gd->disk_name, "ubiblock%d_%d", dev->ubi_num, dev->vol_id);
 416         set_capacity(gd, disk_capacity);
 417         dev->gd = gd;
 418 
 419         dev->tag_set.ops = &ubiblock_mq_ops;
 420         dev->tag_set.queue_depth = 64;
 421         dev->tag_set.numa_node = NUMA_NO_NODE;
 422         dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 423         dev->tag_set.cmd_size = sizeof(struct ubiblock_pdu);
 424         dev->tag_set.driver_data = dev;
 425         dev->tag_set.nr_hw_queues = 1;
 426 
 427         ret = blk_mq_alloc_tag_set(&dev->tag_set);
 428         if (ret) {
 429                 dev_err(disk_to_dev(dev->gd), "blk_mq_alloc_tag_set failed");
 430                 goto out_remove_minor;
 431         }
 432 
 433         dev->rq = blk_mq_init_queue(&dev->tag_set);
 434         if (IS_ERR(dev->rq)) {
 435                 dev_err(disk_to_dev(gd), "blk_mq_init_queue failed");
 436                 ret = PTR_ERR(dev->rq);
 437                 goto out_free_tags;
 438         }
 439         blk_queue_max_segments(dev->rq, UBI_MAX_SG_COUNT);
 440 
 441         dev->rq->queuedata = dev;
 442         dev->gd->queue = dev->rq;
 443 
 444         /*
 445          * Create one workqueue per volume (per registered block device).
 446          * Rembember workqueues are cheap, they're not threads.
 447          */
 448         dev->wq = alloc_workqueue("%s", 0, 0, gd->disk_name);
 449         if (!dev->wq) {
 450                 ret = -ENOMEM;
 451                 goto out_free_queue;
 452         }
 453 
 454         list_add_tail(&dev->list, &ubiblock_devices);
 455 
 456         /* Must be the last step: anyone can call file ops from now on */
 457         add_disk(dev->gd);
 458         dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)",
 459                  dev->ubi_num, dev->vol_id, vi->name);
 460         mutex_unlock(&devices_mutex);
 461         return 0;
 462 
 463 out_free_queue:
 464         blk_cleanup_queue(dev->rq);
 465 out_free_tags:
 466         blk_mq_free_tag_set(&dev->tag_set);
 467 out_remove_minor:
 468         idr_remove(&ubiblock_minor_idr, gd->first_minor);
 469 out_put_disk:
 470         put_disk(dev->gd);
 471 out_free_dev:
 472         kfree(dev);
 473 out_unlock:
 474         mutex_unlock(&devices_mutex);
 475 
 476         return ret;
 477 }
 478 
 479 static void ubiblock_cleanup(struct ubiblock *dev)
 480 {
 481         /* Stop new requests to arrive */
 482         del_gendisk(dev->gd);
 483         /* Flush pending work */
 484         destroy_workqueue(dev->wq);
 485         /* Finally destroy the blk queue */
 486         blk_cleanup_queue(dev->rq);
 487         blk_mq_free_tag_set(&dev->tag_set);
 488         dev_info(disk_to_dev(dev->gd), "released");
 489         idr_remove(&ubiblock_minor_idr, dev->gd->first_minor);
 490         put_disk(dev->gd);
 491 }
 492 
 493 int ubiblock_remove(struct ubi_volume_info *vi)
 494 {
 495         struct ubiblock *dev;
 496         int ret;
 497 
 498         mutex_lock(&devices_mutex);
 499         dev = find_dev_nolock(vi->ubi_num, vi->vol_id);
 500         if (!dev) {
 501                 ret = -ENODEV;
 502                 goto out_unlock;
 503         }
 504 
 505         /* Found a device, let's lock it so we can check if it's busy */
 506         mutex_lock(&dev->dev_mutex);
 507         if (dev->refcnt > 0) {
 508                 ret = -EBUSY;
 509                 goto out_unlock_dev;
 510         }
 511 
 512         /* Remove from device list */
 513         list_del(&dev->list);
 514         ubiblock_cleanup(dev);
 515         mutex_unlock(&dev->dev_mutex);
 516         mutex_unlock(&devices_mutex);
 517 
 518         kfree(dev);
 519         return 0;
 520 
 521 out_unlock_dev:
 522         mutex_unlock(&dev->dev_mutex);
 523 out_unlock:
 524         mutex_unlock(&devices_mutex);
 525         return ret;
 526 }
 527 
 528 static int ubiblock_resize(struct ubi_volume_info *vi)
 529 {
 530         struct ubiblock *dev;
 531         u64 disk_capacity;
 532         int ret;
 533 
 534         /*
 535          * Need to lock the device list until we stop using the device,
 536          * otherwise the device struct might get released in
 537          * 'ubiblock_remove()'.
 538          */
 539         mutex_lock(&devices_mutex);
 540         dev = find_dev_nolock(vi->ubi_num, vi->vol_id);
 541         if (!dev) {
 542                 mutex_unlock(&devices_mutex);
 543                 return -ENODEV;
 544         }
 545 
 546         ret = calc_disk_capacity(vi, &disk_capacity);
 547         if (ret) {
 548                 mutex_unlock(&devices_mutex);
 549                 if (ret == -EFBIG) {
 550                         dev_warn(disk_to_dev(dev->gd),
 551                                  "the volume is too big (%d LEBs), cannot resize",
 552                                  vi->size);
 553                 }
 554                 return ret;
 555         }
 556 
 557         mutex_lock(&dev->dev_mutex);
 558 
 559         if (get_capacity(dev->gd) != disk_capacity) {
 560                 set_capacity(dev->gd, disk_capacity);
 561                 dev_info(disk_to_dev(dev->gd), "resized to %lld bytes",
 562                          vi->used_bytes);
 563         }
 564         mutex_unlock(&dev->dev_mutex);
 565         mutex_unlock(&devices_mutex);
 566         return 0;
 567 }
 568 
 569 static int ubiblock_notify(struct notifier_block *nb,
 570                          unsigned long notification_type, void *ns_ptr)
 571 {
 572         struct ubi_notification *nt = ns_ptr;
 573 
 574         switch (notification_type) {
 575         case UBI_VOLUME_ADDED:
 576                 /*
 577                  * We want to enforce explicit block device creation for
 578                  * volumes, so when a volume is added we do nothing.
 579                  */
 580                 break;
 581         case UBI_VOLUME_REMOVED:
 582                 ubiblock_remove(&nt->vi);
 583                 break;
 584         case UBI_VOLUME_RESIZED:
 585                 ubiblock_resize(&nt->vi);
 586                 break;
 587         case UBI_VOLUME_UPDATED:
 588                 /*
 589                  * If the volume is static, a content update might mean the
 590                  * size (i.e. used_bytes) was also changed.
 591                  */
 592                 if (nt->vi.vol_type == UBI_STATIC_VOLUME)
 593                         ubiblock_resize(&nt->vi);
 594                 break;
 595         default:
 596                 break;
 597         }
 598         return NOTIFY_OK;
 599 }
 600 
 601 static struct notifier_block ubiblock_notifier = {
 602         .notifier_call = ubiblock_notify,
 603 };
 604 
 605 static struct ubi_volume_desc * __init
 606 open_volume_desc(const char *name, int ubi_num, int vol_id)
 607 {
 608         if (ubi_num == -1)
 609                 /* No ubi num, name must be a vol device path */
 610                 return ubi_open_volume_path(name, UBI_READONLY);
 611         else if (vol_id == -1)
 612                 /* No vol_id, must be vol_name */
 613                 return ubi_open_volume_nm(ubi_num, name, UBI_READONLY);
 614         else
 615                 return ubi_open_volume(ubi_num, vol_id, UBI_READONLY);
 616 }
 617 
 618 static void __init ubiblock_create_from_param(void)
 619 {
 620         int i, ret = 0;
 621         struct ubiblock_param *p;
 622         struct ubi_volume_desc *desc;
 623         struct ubi_volume_info vi;
 624 
 625         /*
 626          * If there is an error creating one of the ubiblocks, continue on to
 627          * create the following ubiblocks. This helps in a circumstance where
 628          * the kernel command-line specifies multiple block devices and some
 629          * may be broken, but we still want the working ones to come up.
 630          */
 631         for (i = 0; i < ubiblock_devs; i++) {
 632                 p = &ubiblock_param[i];
 633 
 634                 desc = open_volume_desc(p->name, p->ubi_num, p->vol_id);
 635                 if (IS_ERR(desc)) {
 636                         pr_err(
 637                                "UBI: block: can't open volume on ubi%d_%d, err=%ld\n",
 638                                p->ubi_num, p->vol_id, PTR_ERR(desc));
 639                         continue;
 640                 }
 641 
 642                 ubi_get_volume_info(desc, &vi);
 643                 ubi_close_volume(desc);
 644 
 645                 ret = ubiblock_create(&vi);
 646                 if (ret) {
 647                         pr_err(
 648                                "UBI: block: can't add '%s' volume on ubi%d_%d, err=%d\n",
 649                                vi.name, p->ubi_num, p->vol_id, ret);
 650                         continue;
 651                 }
 652         }
 653 }
 654 
 655 static void ubiblock_remove_all(void)
 656 {
 657         struct ubiblock *next;
 658         struct ubiblock *dev;
 659 
 660         mutex_lock(&devices_mutex);
 661         list_for_each_entry_safe(dev, next, &ubiblock_devices, list) {
 662                 /* The module is being forcefully removed */
 663                 WARN_ON(dev->desc);
 664                 /* Remove from device list */
 665                 list_del(&dev->list);
 666                 ubiblock_cleanup(dev);
 667                 kfree(dev);
 668         }
 669         mutex_unlock(&devices_mutex);
 670 }
 671 
 672 int __init ubiblock_init(void)
 673 {
 674         int ret;
 675 
 676         ubiblock_major = register_blkdev(0, "ubiblock");
 677         if (ubiblock_major < 0)
 678                 return ubiblock_major;
 679 
 680         /*
 681          * Attach block devices from 'block=' module param.
 682          * Even if one block device in the param list fails to come up,
 683          * still allow the module to load and leave any others up.
 684          */
 685         ubiblock_create_from_param();
 686 
 687         /*
 688          * Block devices are only created upon user requests, so we ignore
 689          * existing volumes.
 690          */
 691         ret = ubi_register_volume_notifier(&ubiblock_notifier, 1);
 692         if (ret)
 693                 goto err_unreg;
 694         return 0;
 695 
 696 err_unreg:
 697         unregister_blkdev(ubiblock_major, "ubiblock");
 698         ubiblock_remove_all();
 699         return ret;
 700 }
 701 
 702 void __exit ubiblock_exit(void)
 703 {
 704         ubi_unregister_volume_notifier(&ubiblock_notifier);
 705         ubiblock_remove_all();
 706         unregister_blkdev(ubiblock_major, "ubiblock");
 707 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/mtd/ubi/block.c

DEFINITIONS
