target/linux/generic/patches-2.6.37/065-rootfs_split.patch

   1 --- a/drivers/mtd/Kconfig
   2 +++ b/drivers/mtd/Kconfig
   3 @@ -53,6 +53,16 @@ config MTD_PARTITIONS
   4           devices. Partitioning on NFTL 'devices' is a different - that's the
   5           'normal' form of partitioning used on a block device.
   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 @@ -29,6 +29,8 @@
  23  #include <linux/kmod.h>
  24  #include <linux/mtd/mtd.h>
  25  #include <linux/mtd/partitions.h>
  26 +#include <linux/root_dev.h>
  27 +#include <linux/magic.h>
  28  #include <linux/err.h>
  29
  30  /* Our partition linked list */
  31 @@ -48,7 +50,7 @@ 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 @@ -618,6 +620,153 @@ int mtd_del_partition(struct mtd_info *m
  41  }
  42  EXPORT_SYMBOL_GPL(mtd_del_partition);
  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 +{
  93 +       struct mtd_partition *dpart;
  94 +       struct mtd_part *slave = NULL;
  95 +       int ret, split_offset = 0;
  96 +
  97 +       ret = split_squashfs(master, part->offset, &split_offset);
  98 +       if (ret)
  99 +               return ret;
 100 +
 101 +       if (split_offset <= 0)
 102 +               return 0;
 103 +
 104 +       dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
 105 +       if (dpart == NULL) {
 106 +               printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
 107 +                       ROOTFS_SPLIT_NAME);
 108 +               return -ENOMEM;
 109 +       }
 110 +
 111 +       memcpy(dpart, part, sizeof(*part));
 112 +       dpart->name = (unsigned char *)&dpart[1];
 113 +       strcpy(dpart->name, ROOTFS_SPLIT_NAME);
 114 +
 115 +       dpart->size -= split_offset - dpart->offset;
 116 +       dpart->offset = split_offset;
 117 +
 118 +       if (dpart == NULL)
 119 +               return 1;
 120 +
 121 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%llX, len=%llX \n",
 122 +               ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
 123 +
 124 +       slave = allocate_partition(master, dpart, 0, split_offset);
 125 +       if (IS_ERR(slave))
 126 +               return PTR_ERR(slave);
 127 +       mutex_lock(&mtd_partitions_mutex);
 128 +       list_add(&slave->list, &mtd_partitions);
 129 +       mutex_unlock(&mtd_partitions_mutex);
 130 +
 131 +       add_mtd_device(&slave->mtd);
 132 +
 133 +       rpart->split = &slave->mtd;
 134 +
 135 +       return 0;
 136 +}
 137 +
 138 +static int refresh_rootfs_split(struct mtd_info *mtd)
 139 +{
 140 +       struct mtd_partition tpart;
 141 +       struct mtd_part *part;
 142 +       char *name;
 143 +       //int index = 0;
 144 +       int offset, size;
 145 +       int ret;
 146 +
 147 +       part = PART(mtd);
 148 +
 149 +       /* check for the new squashfs offset first */
 150 +       ret = split_squashfs(part->master, part->offset, &offset);
 151 +       if (ret)
 152 +               return ret;
 153 +
 154 +       if ((offset > 0) && !mtd->split) {
 155 +               printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
 156 +               /* if we don't have a rootfs split partition, create a new one */
 157 +               tpart.name = (char *) mtd->name;
 158 +               tpart.size = mtd->size;
 159 +               tpart.offset = part->offset;
 160 +
 161 +               return split_rootfs_data(part->master, &part->mtd, &tpart);
 162 +       } else if ((offset > 0) && mtd->split) {
 163 +               /* update the offsets of the existing partition */
 164 +               size = mtd->size + part->offset - offset;
 165 +
 166 +               part = PART(mtd->split);
 167 +               part->offset = offset;
 168 +               part->mtd.size = size;
 169 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
 170 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
 171 +                       (u32) part->offset, (u32) part->mtd.size);
 172 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 173 +               strcpy(name, ROOTFS_SPLIT_NAME);
 174 +               part->mtd.name = name;
 175 +       } else if ((offset <= 0) && mtd->split) {
 176 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
 177 +
 178 +               /* mark existing partition as removed */
 179 +               part = PART(mtd->split);
 180 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 181 +               strcpy(name, ROOTFS_REMOVED_NAME);
 182 +               part->mtd.name = name;
 183 +               part->offset = 0;
 184 +               part->mtd.size = 0;
 185 +       }
 186 +
 187 +       return 0;
 188 +}
 189 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
 190 +
 191  /*
 192   * This function, given a master MTD object and a partition table, creates
 193   * and registers slave MTD objects which are bound to the master according to
 194 @@ -633,7 +782,7 @@ int add_mtd_partitions(struct mtd_info *
 195  {
 196         struct mtd_part *slave;
 197         uint64_t cur_offset = 0;
 198 -       int i;
 199 +       int i, ret;
 200
 201         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 202
 203 @@ -648,6 +797,21 @@ int add_mtd_partitions(struct mtd_info *
 204
 205                 add_mtd_device(&slave->mtd);
 206
 207 +               if (!strcmp(parts[i].name, "rootfs")) {
 208 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
 209 +                       if (ROOT_DEV == 0) {
 210 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
 211 +                                       "set to be root filesystem\n");
 212 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
 213 +                       }
 214 +#endif
 215 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 216 +                       ret = split_rootfs_data(master, &slave->mtd, &parts[i]);
 217 +                       /* if (ret == 0)
 218 +                        *      j++; */
 219 +#endif
 220 +               }
 221 +
 222                 cur_offset = slave->offset + slave->mtd.size;
 223         }
 224
 225 @@ -655,6 +819,32 @@ int add_mtd_partitions(struct mtd_info *
 226  }
 227  EXPORT_SYMBOL(add_mtd_partitions);
 228
 229 +int refresh_mtd_partitions(struct mtd_info *mtd)
 230 +{
 231 +       int ret = 0;
 232 +
 233 +       if (IS_PART(mtd)) {
 234 +               struct mtd_part *part;
 235 +               struct mtd_info *master;
 236 +
 237 +               part = PART(mtd);
 238 +               master = part->master;
 239 +               if (master->refresh_device)
 240 +                       ret = master->refresh_device(master);
 241 +       }
 242 +
 243 +       if (!ret && mtd->refresh_device)
 244 +               ret = mtd->refresh_device(mtd);
 245 +
 246 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 247 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
 248 +               refresh_rootfs_split(mtd);
 249 +#endif
 250 +
 251 +       return 0;
 252 +}
 253 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
 254 +
 255  static DEFINE_SPINLOCK(part_parser_lock);
 256  static LIST_HEAD(part_parsers);
 257
 258 --- a/drivers/mtd/devices/block2mtd.c
 259 +++ b/drivers/mtd/devices/block2mtd.c
 260 @@ -30,6 +30,8 @@ struct block2mtd_dev {
 261         struct block_device *blkdev;
 262         struct mtd_info mtd;
 263         struct mutex write_mutex;
 264 +       rwlock_t bdev_mutex;
 265 +       char devname[0];
 266  };
 267
 268
 269 @@ -82,6 +84,12 @@ static int block2mtd_erase(struct mtd_in
 270         size_t len = instr->len;
 271         int err;
 272
 273 +       read_lock(&dev->bdev_mutex);
 274 +       if (!dev->blkdev) {
 275 +               err = -EINVAL;
 276 +               goto done;
 277 +       }
 278 +
 279         instr->state = MTD_ERASING;
 280         mutex_lock(&dev->write_mutex);
 281         err = _block2mtd_erase(dev, from, len);
 282 @@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
 283                 instr->state = MTD_ERASE_DONE;
 284
 285         mtd_erase_callback(instr);
 286 +
 287 +done:
 288 +       read_unlock(&dev->bdev_mutex);
 289 +
 290         return err;
 291  }
 292
 293 @@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
 294         struct page *page;
 295         int index = from >> PAGE_SHIFT;
 296         int offset = from & (PAGE_SIZE-1);
 297 -       int cpylen;
 298 +       int cpylen, err = 0;
 299 +
 300 +       read_lock(&dev->bdev_mutex);
 301 +       if (!dev->blkdev || (from > mtd->size)) {
 302 +               err = -EINVAL;
 303 +               goto done;
 304 +       }
 305
 306 -       if (from > mtd->size)
 307 -               return -EINVAL;
 308         if (from + len > mtd->size)
 309                 len = mtd->size - from;
 310
 311 @@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
 312                 len = len - cpylen;
 313
 314                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
 315 -               if (!page)
 316 -                       return -ENOMEM;
 317 -               if (IS_ERR(page))
 318 -                       return PTR_ERR(page);
 319 +               if (!page) {
 320 +                       err = -ENOMEM;
 321 +                       goto done;
 322 +               }
 323 +               if (IS_ERR(page)) {
 324 +                       err = PTR_ERR(page);
 325 +                       goto done;
 326 +               }
 327
 328                 memcpy(buf, page_address(page) + offset, cpylen);
 329                 page_cache_release(page);
 330 @@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
 331                 offset = 0;
 332                 index++;
 333         }
 334 -       return 0;
 335 +
 336 +done:
 337 +       read_unlock(&dev->bdev_mutex);
 338 +       return err;
 339  }
 340
 341
 342 @@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
 343                 size_t *retlen, const u_char *buf)
 344  {
 345         struct block2mtd_dev *dev = mtd->priv;
 346 -       int err;
 347 +       int err = 0;
 348 +
 349 +       read_lock(&dev->bdev_mutex);
 350 +       if (!dev->blkdev) {
 351 +               err = -EINVAL;
 352 +               goto done;
 353 +       }
 354
 355         if (!len)
 356 -               return 0;
 357 -       if (to >= mtd->size)
 358 -               return -ENOSPC;
 359 +               goto done;
 360 +
 361 +       if (to >= mtd->size) {
 362 +               err = -ENOSPC;
 363 +               goto done;
 364 +       }
 365 +
 366         if (to + len > mtd->size)
 367                 len = mtd->size - to;
 368
 369 @@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
 370         mutex_unlock(&dev->write_mutex);
 371         if (err > 0)
 372                 err = 0;
 373 +
 374 +done:
 375 +       read_unlock(&dev->bdev_mutex);
 376         return err;
 377  }
 378
 379 @@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
 380  static void block2mtd_sync(struct mtd_info *mtd)
 381  {
 382         struct block2mtd_dev *dev = mtd->priv;
 383 -       sync_blockdev(dev->blkdev);
 384 -       return;
 385 -}
 386 -
 387 -
 388 -static void block2mtd_free_device(struct block2mtd_dev *dev)
 389 -{
 390 -       if (!dev)
 391 -               return;
 392 -
 393 -       kfree(dev->mtd.name);
 394
 395 -       if (dev->blkdev) {
 396 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 397 -                                       0, -1);
 398 -               close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 399 -       }
 400 +       read_lock(&dev->bdev_mutex);
 401 +       if (dev->blkdev)
 402 +               sync_blockdev(dev->blkdev);
 403 +       read_unlock(&dev->bdev_mutex);
 404
 405 -       kfree(dev);
 406 +       return;
 407  }
 408
 409
 410 -/* FIXME: ensure that mtd->size % erase_size == 0 */
 411 -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
 412 +static int _open_bdev(struct block2mtd_dev *dev)
 413  {
 414         struct block_device *bdev;
 415 -       struct block2mtd_dev *dev;
 416 -       struct mtd_partition *part;
 417 -       char *name;
 418 -
 419 -       if (!devname)
 420 -               return NULL;
 421 -
 422 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
 423 -       if (!dev)
 424 -               return NULL;
 425
 426         /* Get a handle on the device */
 427 -       bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
 428 +       bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
 429  #ifndef MODULE
 430         if (IS_ERR(bdev)) {
 431
 432                 /* We might not have rootfs mounted at this point. Try
 433                    to resolve the device name by other means. */
 434
 435 -               dev_t devt = name_to_dev_t(devname);
 436 +               dev_t devt = name_to_dev_t(dev->devname);
 437                 if (devt) {
 438                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 439                 }
 440 @@ -263,17 +276,98 @@ static struct block2mtd_dev *add_device(
 441  #endif
 442
 443         if (IS_ERR(bdev)) {
 444 -               ERROR("error: cannot open device %s", devname);
 445 -               goto devinit_err;
 446 +               ERROR("error: cannot open device %s", dev->devname);
 447 +               return 1;
 448         }
 449         dev->blkdev = bdev;
 450
 451         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 452                 ERROR("attempting to use an MTD device as a block device");
 453 -               goto devinit_err;
 454 +               return 1;
 455         }
 456
 457 +       return 0;
 458 +}
 459 +
 460 +static void _close_bdev(struct block2mtd_dev *dev)
 461 +{
 462 +       struct block_device *bdev;
 463 +
 464 +       if (!dev->blkdev)
 465 +               return;
 466 +
 467 +       bdev = dev->blkdev;
 468 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
 469 +       close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 470 +       dev->blkdev = NULL;
 471 +}
 472 +
 473 +static void block2mtd_free_device(struct block2mtd_dev *dev)
 474 +{
 475 +       if (!dev)
 476 +               return;
 477 +
 478 +       kfree(dev->mtd.name);
 479 +       _close_bdev(dev);
 480 +       kfree(dev);
 481 +}
 482 +
 483 +
 484 +static int block2mtd_refresh(struct mtd_info *mtd)
 485 +{
 486 +       struct block2mtd_dev *dev = mtd->priv;
 487 +       struct block_device *bdev;
 488 +       dev_t devt;
 489 +       int err = 0;
 490 +
 491 +       /* no other mtd function can run at this point */
 492 +       write_lock(&dev->bdev_mutex);
 493 +
 494 +       /* get the device number for the whole disk */
 495 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
 496 +
 497 +       /* close the old block device */
 498 +       _close_bdev(dev);
 499 +
 500 +       /* open the whole disk, issue a partition rescan, then */
 501 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 502 +       if (!bdev || !bdev->bd_disk)
 503 +               err = -EINVAL;
 504 +#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
 505 +       else
 506 +               err = rescan_partitions(bdev->bd_disk, bdev);
 507 +#endif
 508 +       if (bdev)
 509 +               close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
 510 +
 511 +       /* try to open the partition block device again */
 512 +       _open_bdev(dev);
 513 +       write_unlock(&dev->bdev_mutex);
 514 +
 515 +       return err;
 516 +}
 517 +
 518 +/* FIXME: ensure that mtd->size % erase_size == 0 */
 519 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
 520 +{
 521 +       struct block2mtd_dev *dev;
 522 +       struct mtd_partition *part;
 523 +       char *name;
 524 +
 525 +       if (!devname)
 526 +               return NULL;
 527 +
 528 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 529 +       if (!dev)
 530 +               return NULL;
 531 +
 532 +       strcpy(dev->devname, devname);
 533 +
 534 +       if (_open_bdev(dev))
 535 +               goto devinit_err;
 536 +
 537         mutex_init(&dev->write_mutex);
 538 +       rwlock_init(&dev->bdev_mutex);
 539
 540         /* Setup the MTD structure */
 541         /* make the name contain the block device in */
 542 @@ -298,6 +392,7 @@ static struct block2mtd_dev *add_device(
 543         dev->mtd.read = block2mtd_read;
 544         dev->mtd.priv = dev;
 545         dev->mtd.owner = THIS_MODULE;
 546 +       dev->mtd.refresh_device = block2mtd_refresh;
 547
 548         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 549         part->name = dev->mtd.name;
 550 --- a/drivers/mtd/mtdchar.c
 551 +++ b/drivers/mtd/mtdchar.c
 552 @@ -841,6 +841,13 @@ static int mtd_ioctl(struct file *file,
 553                 file->f_pos = 0;
 554                 break;
 555         }
 556 +#ifdef CONFIG_MTD_PARTITIONS
 557 +       case MTDREFRESH:
 558 +       {
 559 +               ret = refresh_mtd_partitions(mtd);
 560 +               break;
 561 +       }
 562 +#endif
 563
 564         case OTPGETREGIONCOUNT:
 565         case OTPGETREGIONINFO:
 566 --- a/include/linux/mtd/mtd.h
 567 +++ b/include/linux/mtd/mtd.h
 568 @@ -125,6 +125,7 @@ struct nand_ecclayout {
 569         struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
 570  };
 571
 572 +struct mtd_info;
 573  struct mtd_info {
 574         u_char type;
 575         uint32_t flags;
 576 @@ -266,6 +267,9 @@ struct mtd_info {
 577         struct device dev;
 578         int usecount;
 579
 580 +       int (*refresh_device)(struct mtd_info *mtd);
 581 +       struct mtd_info *split;
 582 +
 583         /* If the driver is something smart, like UBI, it may need to maintain
 584          * its own reference counting. The below functions are only for driver.
 585          * The driver may register its callbacks. These callbacks are not
 586 --- a/include/linux/mtd/partitions.h
 587 +++ b/include/linux/mtd/partitions.h
 588 @@ -34,12 +34,14 @@
 589   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
 590   */
 591
 592 +struct mtd_partition;
 593  struct mtd_partition {
 594         char *name;                     /* identifier string */
 595         uint64_t size;                  /* partition size */
 596         uint64_t offset;                /* offset within the master MTD space */
 597         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
 598         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only) */
 599 +       int (*refresh_partition)(struct mtd_info *);
 600  };
 601
 602  #define MTDPART_OFS_NXTBLK     (-2)
 603 @@ -51,6 +53,7 @@ struct mtd_info;
 604
 605  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 606  int del_mtd_partitions(struct mtd_info *);
 607 +int refresh_mtd_partitions(struct mtd_info *);
 608
 609  /*
 610   * Functions dealing with the various ways of partitioning the space
 611 --- a/include/mtd/mtd-abi.h
 612 +++ b/include/mtd/mtd-abi.h
 613 @@ -127,6 +127,7 @@ struct otp_info {
 614  #define MEMWRITEOOB64          _IOWR('M', 21, struct mtd_oob_buf64)
 615  #define MEMREADOOB64           _IOWR('M', 22, struct mtd_oob_buf64)
 616  #define MEMISLOCKED            _IOR('M', 23, struct erase_info_user)
 617 +#define MTDREFRESH             _IO('M', 23)
 618
 619  /*
 620   * Obsolete legacy interface. Keep it in order not to break userspace