target/linux/generic/patches-2.6.30/065-rootfs_split.patch

   1 --- a/drivers/mtd/Kconfig
   2 +++ b/drivers/mtd/Kconfig
   3 @@ -53,6 +53,16 @@ config MTD_TESTS
   4           should normally be compiled as kernel modules. The modules perform
   5           various checks and verifications when loaded.
   6
   7 +config MTD_ROOTFS_ROOT_DEV
   8 +       bool "Automatically set 'rootfs' partition to be root filesystem"
   9 +       depends on MTD_PARTITIONS
  10 +       default y
  11 +
  12 +config MTD_ROOTFS_SPLIT
  13 +       bool "Automatically split 'rootfs' partition for squashfs"
  14 +       depends on MTD_PARTITIONS
  15 +       default y
  16 +
  17  config MTD_REDBOOT_PARTS
  18         tristate "RedBoot partition table parsing"
  19         depends on MTD_PARTITIONS
  20 --- a/drivers/mtd/mtdpart.c
  21 +++ b/drivers/mtd/mtdpart.c
  22 @@ -18,6 +18,8 @@
  23  #include <linux/mtd/mtd.h>
  24  #include <linux/mtd/partitions.h>
  25  #include <linux/mtd/compatmac.h>
  26 +#include <linux/root_dev.h>
  27 +#include <linux/magic.h>
  28
  29  /* Our partition linked list */
  30  static LIST_HEAD(mtd_partitions);
  31 @@ -37,7 +39,7 @@ struct mtd_part {
  32   * the pointer to that structure with this macro.
  33   */
  34  #define PART(x)  ((struct mtd_part *)(x))
  35 -
  36 +#define IS_PART(mtd) (mtd->read == part_read)
  37
  38  /*
  39   * MTD methods which simply translate the effective address and pass through
  40 @@ -512,6 +514,155 @@ out_register:
  41         return slave;
  42  }
  43
  44 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
  45 +#define ROOTFS_SPLIT_NAME "rootfs_data"
  46 +#define ROOTFS_REMOVED_NAME "<removed>"
  47 +
  48 +struct squashfs_super_block {
  49 +       __le32 s_magic;
  50 +       __le32 pad0[9];
  51 +       __le64 bytes_used;
  52 +};
  53 +
  54 +
  55 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
  56 +{
  57 +       struct squashfs_super_block sb;
  58 +       int len, ret;
  59 +
  60 +       ret = master->read(master, offset, sizeof(sb), &len, (void *) &sb);
  61 +       if (ret || (len != sizeof(sb))) {
  62 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
  63 +                       "from \"%s\"\n", master->name);
  64 +               return -EINVAL;
  65 +       }
  66 +
  67 +       if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
  68 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
  69 +                       master->name);
  70 +               *split_offset = 0;
  71 +               return 0;
  72 +       }
  73 +
  74 +       if (le64_to_cpu((sb.bytes_used)) <= 0) {
  75 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
  76 +                       master->name);
  77 +               *split_offset = 0;
  78 +               return 0;
  79 +       }
  80 +
  81 +       len = (u32) le64_to_cpu(sb.bytes_used);
  82 +       len += (offset & 0x000fffff);
  83 +       len +=  (master->erasesize - 1);
  84 +       len &= ~(master->erasesize - 1);
  85 +       len -= (offset & 0x000fffff);
  86 +       *split_offset = offset + len;
  87 +
  88 +       return 0;
  89 +}
  90 +
  91 +static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, const struct mtd_partition *part,
  92 +               int index)
  93 +{
  94 +       struct mtd_partition *dpart;
  95 +       struct mtd_part *slave = NULL;
  96 +       int split_offset = 0;
  97 +       int ret;
  98 +
  99 +       ret = split_squashfs(master, part->offset, &split_offset);
 100 +       if (ret)
 101 +               return ret;
 102 +
 103 +       if (split_offset <= 0)
 104 +               return 0;
 105 +
 106 +       dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
 107 +       if (dpart == NULL) {
 108 +               printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
 109 +                       ROOTFS_SPLIT_NAME);
 110 +               return -ENOMEM;
 111 +       }
 112 +
 113 +       memcpy(dpart, part, sizeof(*part));
 114 +       dpart->name = (unsigned char *)&dpart[1];
 115 +       strcpy(dpart->name, ROOTFS_SPLIT_NAME);
 116 +
 117 +       dpart->size -= split_offset - dpart->offset;
 118 +       dpart->offset = split_offset;
 119 +
 120 +       if (dpart == NULL)
 121 +               return 1;
 122 +
 123 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%llX, len=%llX \n",
 124 +               ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
 125 +
 126 +       slave = add_one_partition(master, dpart, index, split_offset);
 127 +       if (!slave) {
 128 +               kfree(dpart);
 129 +               return -ENOMEM;
 130 +       }
 131 +       rpart->split = &slave->mtd;
 132 +
 133 +       return 0;
 134 +}
 135 +
 136 +static int refresh_rootfs_split(struct mtd_info *mtd)
 137 +{
 138 +       struct mtd_partition tpart;
 139 +       struct mtd_part *part;
 140 +       char *name;
 141 +       int index = 0;
 142 +       int offset, size;
 143 +       int ret;
 144 +
 145 +       part = PART(mtd);
 146 +
 147 +       /* check for the new squashfs offset first */
 148 +       ret = split_squashfs(part->master, part->offset, &offset);
 149 +       if (ret)
 150 +               return ret;
 151 +
 152 +       if ((offset > 0) && !mtd->split) {
 153 +               printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
 154 +               /* if we don't have a rootfs split partition, create a new one */
 155 +               tpart.name = (char *) mtd->name;
 156 +               tpart.size = mtd->size;
 157 +               tpart.offset = part->offset;
 158 +
 159 +               /* find the index of the last partition */
 160 +               if (!list_empty(&mtd_partitions))
 161 +                       index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
 162 +
 163 +               return split_rootfs_data(part->master, &part->mtd, &tpart, index);
 164 +       } else if ((offset > 0) && mtd->split) {
 165 +               /* update the offsets of the existing partition */
 166 +               size = mtd->size + part->offset - offset;
 167 +
 168 +               part = PART(mtd->split);
 169 +               part->offset = offset;
 170 +               part->mtd.size = size;
 171 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
 172 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
 173 +                       (u32) part->offset, (u32) part->mtd.size);
 174 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 175 +               strcpy(name, ROOTFS_SPLIT_NAME);
 176 +               part->mtd.name = name;
 177 +       } else if ((offset <= 0) && mtd->split) {
 178 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
 179 +
 180 +               /* mark existing partition as removed */
 181 +               part = PART(mtd->split);
 182 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 183 +               strcpy(name, ROOTFS_REMOVED_NAME);
 184 +               part->mtd.name = name;
 185 +               part->offset = 0;
 186 +               part->mtd.size = 0;
 187 +       }
 188 +
 189 +       return 0;
 190 +}
 191 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
 192 +
 193  /*
 194   * This function, given a master MTD object and a partition table, creates
 195   * and registers slave MTD objects which are bound to the master according to
 196 @@ -527,14 +678,29 @@ int add_mtd_partitions(struct mtd_info *
 197  {
 198         struct mtd_part *slave;
 199         uint64_t cur_offset = 0;
 200 -       int i;
 201 +       int i, j, ret;
 202
 203         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 204
 205 -       for (i = 0; i < nbparts; i++) {
 206 -               slave = add_one_partition(master, parts + i, i, cur_offset);
 207 +       for (i = 0, j = 0; i < nbparts; i++) {
 208 +               slave = add_one_partition(master, parts + i, j++, cur_offset);
 209                 if (!slave)
 210                         return -ENOMEM;
 211 +
 212 +               if (!strcmp(parts[i].name, "rootfs") && slave->registered) {
 213 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
 214 +                       if (ROOT_DEV == 0) {
 215 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
 216 +                                       "set to be root filesystem\n");
 217 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
 218 +                       }
 219 +#endif
 220 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 221 +                       ret = split_rootfs_data(master, &slave->mtd, &parts[i], j);
 222 +                       if (ret == 0)
 223 +                               j++;
 224 +#endif
 225 +               }
 226                 cur_offset = slave->offset + slave->mtd.size;
 227         }
 228
 229 @@ -542,6 +708,32 @@ int add_mtd_partitions(struct mtd_info *
 230  }
 231  EXPORT_SYMBOL(add_mtd_partitions);
 232
 233 +int refresh_mtd_partitions(struct mtd_info *mtd)
 234 +{
 235 +       int ret = 0;
 236 +
 237 +       if (IS_PART(mtd)) {
 238 +               struct mtd_part *part;
 239 +               struct mtd_info *master;
 240 +
 241 +               part = PART(mtd);
 242 +               master = part->master;
 243 +               if (master->refresh_device)
 244 +                       ret = master->refresh_device(master);
 245 +       }
 246 +
 247 +       if (!ret && mtd->refresh_device)
 248 +               ret = mtd->refresh_device(mtd);
 249 +
 250 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 251 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
 252 +               refresh_rootfs_split(mtd);
 253 +#endif
 254 +
 255 +       return 0;
 256 +}
 257 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
 258 +
 259  static DEFINE_SPINLOCK(part_parser_lock);
 260  static LIST_HEAD(part_parsers);
 261
 262 --- a/drivers/mtd/devices/block2mtd.c
 263 +++ b/drivers/mtd/devices/block2mtd.c
 264 @@ -29,6 +29,8 @@ struct block2mtd_dev {
 265         struct block_device *blkdev;
 266         struct mtd_info mtd;
 267         struct mutex write_mutex;
 268 +       rwlock_t bdev_mutex;
 269 +       char devname[0];
 270  };
 271
 272
 273 @@ -81,6 +83,12 @@ static int block2mtd_erase(struct mtd_in
 274         size_t len = instr->len;
 275         int err;
 276
 277 +       read_lock(&dev->bdev_mutex);
 278 +       if (!dev->blkdev) {
 279 +               err = -EINVAL;
 280 +               goto done;
 281 +       }
 282 +
 283         instr->state = MTD_ERASING;
 284         mutex_lock(&dev->write_mutex);
 285         err = _block2mtd_erase(dev, from, len);
 286 @@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
 287
 288         instr->state = MTD_ERASE_DONE;
 289         mtd_erase_callback(instr);
 290 +
 291 +done:
 292 +       read_unlock(&dev->bdev_mutex);
 293 +
 294         return err;
 295  }
 296
 297 @@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
 298         struct page *page;
 299         int index = from >> PAGE_SHIFT;
 300         int offset = from & (PAGE_SIZE-1);
 301 -       int cpylen;
 302 +       int cpylen, err = 0;
 303 +
 304 +       read_lock(&dev->bdev_mutex);
 305 +       if (!dev->blkdev || (from > mtd->size)) {
 306 +               err = -EINVAL;
 307 +               goto done;
 308 +       }
 309
 310 -       if (from > mtd->size)
 311 -               return -EINVAL;
 312         if (from + len > mtd->size)
 313                 len = mtd->size - from;
 314
 315 @@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
 316                 len = len - cpylen;
 317
 318                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
 319 -               if (!page)
 320 -                       return -ENOMEM;
 321 -               if (IS_ERR(page))
 322 -                       return PTR_ERR(page);
 323 +               if (!page) {
 324 +                       err = -ENOMEM;
 325 +                       goto done;
 326 +               }
 327 +               if (IS_ERR(page)) {
 328 +                       err = PTR_ERR(page);
 329 +                       goto done;
 330 +               }
 331
 332                 memcpy(buf, page_address(page) + offset, cpylen);
 333                 page_cache_release(page);
 334 @@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
 335                 offset = 0;
 336                 index++;
 337         }
 338 -       return 0;
 339 +
 340 +done:
 341 +       read_unlock(&dev->bdev_mutex);
 342 +       return err;
 343  }
 344
 345
 346 @@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
 347                 size_t *retlen, const u_char *buf)
 348  {
 349         struct block2mtd_dev *dev = mtd->priv;
 350 -       int err;
 351 +       int err = 0;
 352 +
 353 +       read_lock(&dev->bdev_mutex);
 354 +       if (!dev->blkdev) {
 355 +               err = -EINVAL;
 356 +               goto done;
 357 +       }
 358
 359         if (!len)
 360 -               return 0;
 361 -       if (to >= mtd->size)
 362 -               return -ENOSPC;
 363 +               goto done;
 364 +
 365 +       if (to >= mtd->size) {
 366 +               err = -ENOSPC;
 367 +               goto done;
 368 +       }
 369 +
 370         if (to + len > mtd->size)
 371                 len = mtd->size - to;
 372
 373 @@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
 374         mutex_unlock(&dev->write_mutex);
 375         if (err > 0)
 376                 err = 0;
 377 +
 378 +done:
 379 +       read_unlock(&dev->bdev_mutex);
 380         return err;
 381  }
 382
 383 @@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
 384  static void block2mtd_sync(struct mtd_info *mtd)
 385  {
 386         struct block2mtd_dev *dev = mtd->priv;
 387 -       sync_blockdev(dev->blkdev);
 388 -       return;
 389 -}
 390 -
 391 -
 392 -static void block2mtd_free_device(struct block2mtd_dev *dev)
 393 -{
 394 -       if (!dev)
 395 -               return;
 396 -
 397 -       kfree(dev->mtd.name);
 398
 399 -       if (dev->blkdev) {
 400 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 401 -                                       0, -1);
 402 -               close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 403 -       }
 404 +       read_lock(&dev->bdev_mutex);
 405 +       if (dev->blkdev)
 406 +               sync_blockdev(dev->blkdev);
 407 +       read_unlock(&dev->bdev_mutex);
 408
 409 -       kfree(dev);
 410 +       return;
 411  }
 412
 413
 414 -/* FIXME: ensure that mtd->size % erase_size == 0 */
 415 -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
 416 +static int _open_bdev(struct block2mtd_dev *dev)
 417  {
 418         struct block_device *bdev;
 419 -       struct block2mtd_dev *dev;
 420 -       struct mtd_partition *part;
 421 -       char *name;
 422 -
 423 -       if (!devname)
 424 -               return NULL;
 425 -
 426 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
 427 -       if (!dev)
 428 -               return NULL;
 429
 430         /* Get a handle on the device */
 431 -       bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
 432 +       bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
 433  #ifndef MODULE
 434         if (IS_ERR(bdev)) {
 435
 436                 /* We might not have rootfs mounted at this point. Try
 437                    to resolve the device name by other means. */
 438
 439 -               dev_t devt = name_to_dev_t(devname);
 440 +               dev_t devt = name_to_dev_t(dev->devname);
 441                 if (devt) {
 442                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 443                 }
 444 @@ -263,17 +276,98 @@ static struct block2mtd_dev *add_device(
 445  #endif
 446
 447         if (IS_ERR(bdev)) {
 448 -               ERROR("error: cannot open device %s", devname);
 449 -               goto devinit_err;
 450 +               ERROR("error: cannot open device %s", dev->devname);
 451 +               return 1;
 452         }
 453         dev->blkdev = bdev;
 454
 455         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 456                 ERROR("attempting to use an MTD device as a block device");
 457 -               goto devinit_err;
 458 +               return 1;
 459         }
 460
 461 +       return 0;
 462 +}
 463 +
 464 +static void _close_bdev(struct block2mtd_dev *dev)
 465 +{
 466 +       struct block_device *bdev;
 467 +
 468 +       if (!dev->blkdev)
 469 +               return;
 470 +
 471 +       bdev = dev->blkdev;
 472 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
 473 +       close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 474 +       dev->blkdev = NULL;
 475 +}
 476 +
 477 +static void block2mtd_free_device(struct block2mtd_dev *dev)
 478 +{
 479 +       if (!dev)
 480 +               return;
 481 +
 482 +       kfree(dev->mtd.name);
 483 +       _close_bdev(dev);
 484 +       kfree(dev);
 485 +}
 486 +
 487 +
 488 +static int block2mtd_refresh(struct mtd_info *mtd)
 489 +{
 490 +       struct block2mtd_dev *dev = mtd->priv;
 491 +       struct block_device *bdev;
 492 +       dev_t devt;
 493 +       int err = 0;
 494 +
 495 +       /* no other mtd function can run at this point */
 496 +       write_lock(&dev->bdev_mutex);
 497 +
 498 +       /* get the device number for the whole disk */
 499 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
 500 +
 501 +       /* close the old block device */
 502 +       _close_bdev(dev);
 503 +
 504 +       /* open the whole disk, issue a partition rescan, then */
 505 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 506 +       if (!bdev || !bdev->bd_disk)
 507 +               err = -EINVAL;
 508 +#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
 509 +       else
 510 +               err = rescan_partitions(bdev->bd_disk, bdev);
 511 +#endif
 512 +       if (bdev)
 513 +               close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
 514 +
 515 +       /* try to open the partition block device again */
 516 +       _open_bdev(dev);
 517 +       write_unlock(&dev->bdev_mutex);
 518 +
 519 +       return err;
 520 +}
 521 +
 522 +/* FIXME: ensure that mtd->size % erase_size == 0 */
 523 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
 524 +{
 525 +       struct block2mtd_dev *dev;
 526 +       struct mtd_partition *part;
 527 +       char *name;
 528 +
 529 +       if (!devname)
 530 +               return NULL;
 531 +
 532 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 533 +       if (!dev)
 534 +               return NULL;
 535 +
 536 +       strcpy(dev->devname, devname);
 537 +
 538 +       if (_open_bdev(dev))
 539 +               goto devinit_err;
 540 +
 541         mutex_init(&dev->write_mutex);
 542 +       rwlock_init(&dev->bdev_mutex);
 543
 544         if (!mtdname)
 545                 mtdname = devname;
 546 @@ -297,6 +391,7 @@ static struct block2mtd_dev *add_device(
 547         dev->mtd.read = block2mtd_read;
 548         dev->mtd.priv = dev;
 549         dev->mtd.owner = THIS_MODULE;
 550 +       dev->mtd.refresh_device = block2mtd_refresh;
 551
 552         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 553         part->name = dev->mtd.name;
 554 --- a/drivers/mtd/mtdchar.c
 555 +++ b/drivers/mtd/mtdchar.c
 556 @@ -17,6 +17,7 @@
 557
 558  #include <linux/mtd/mtd.h>
 559  #include <linux/mtd/compatmac.h>
 560 +#include <linux/mtd/partitions.h>
 561
 562  #include <asm/uaccess.h>
 563
 564 @@ -750,6 +751,13 @@ static int mtd_ioctl(struct inode *inode
 565                 file->f_pos = 0;
 566                 break;
 567         }
 568 +#ifdef CONFIG_MTD_PARTITIONS
 569 +       case MTDREFRESH:
 570 +       {
 571 +               ret = refresh_mtd_partitions(mtd);
 572 +               break;
 573 +       }
 574 +#endif
 575
 576         default:
 577                 ret = -ENOTTY;
 578 --- a/include/linux/mtd/mtd.h
 579 +++ b/include/linux/mtd/mtd.h
 580 @@ -101,6 +101,7 @@ struct mtd_oob_ops {
 581         uint8_t         *oobbuf;
 582  };
 583
 584 +struct mtd_info;
 585  struct mtd_info {
 586         u_char type;
 587         uint32_t flags;
 588 @@ -241,6 +242,9 @@ struct mtd_info {
 589         struct device dev;
 590         int usecount;
 591
 592 +       int (*refresh_device)(struct mtd_info *mtd);
 593 +       struct mtd_info *split;
 594 +
 595         /* If the driver is something smart, like UBI, it may need to maintain
 596          * its own reference counting. The below functions are only for driver.
 597          * The driver may register its callbacks. These callbacks are not
 598 --- a/include/linux/mtd/partitions.h
 599 +++ b/include/linux/mtd/partitions.h
 600 @@ -34,6 +34,7 @@
 601   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
 602   */
 603
 604 +struct mtd_partition;
 605  struct mtd_partition {
 606         char *name;                     /* identifier string */
 607         uint64_t size;                  /* partition size */
 608 @@ -41,6 +42,7 @@ struct mtd_partition {
 609         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
 610         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only)*/
 611         struct mtd_info **mtdp;         /* pointer to store the MTD object */
 612 +       int (*refresh_partition)(struct mtd_info *);
 613  };
 614
 615  #define MTDPART_OFS_NXTBLK     (-2)
 616 @@ -50,6 +52,7 @@ struct mtd_partition {
 617
 618  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 619  int del_mtd_partitions(struct mtd_info *);
 620 +int refresh_mtd_partitions(struct mtd_info *);
 621
 622  /*
 623   * Functions dealing with the various ways of partitioning the space
 624 --- a/include/mtd/mtd-abi.h
 625 +++ b/include/mtd/mtd-abi.h
 626 @@ -95,6 +95,7 @@ struct otp_info {
 627  #define ECCGETLAYOUT           _IOR('M', 17, struct nand_ecclayout)
 628  #define ECCGETSTATS            _IOR('M', 18, struct mtd_ecc_stats)
 629  #define MTDFILEMODE            _IO('M', 19)
 630 +#define MTDREFRESH             _IO('M', 23)
 631
 632  /*
 633   * Obsolete legacy interface. Keep it in order not to break userspace