target/linux/generic/patches-2.6.31/065-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 @@ -35,7 +37,7 @@ 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 @@ -502,6 +504,152 @@ 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 +{
  93 +       struct mtd_partition *dpart;
  94 +       struct mtd_part *slave = NULL;
  95 +       struct mtd_part *spart;
  96 +       int split_offset = 0;
  97 +       int ret;
  98 +
  99 +       spart = PART(rpart);
 100 +       ret = split_squashfs(master, spart->offset, &split_offset);
 101 +       if (ret)
 102 +               return ret;
 103 +
 104 +       if (split_offset <= 0)
 105 +               return 0;
 106 +
 107 +       dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
 108 +       if (dpart == NULL) {
 109 +               printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
 110 +                       ROOTFS_SPLIT_NAME);
 111 +               return -ENOMEM;
 112 +       }
 113 +
 114 +       memcpy(dpart, part, sizeof(*part));
 115 +       dpart->name = (unsigned char *)&dpart[1];
 116 +       strcpy(dpart->name, ROOTFS_SPLIT_NAME);
 117 +
 118 +       dpart->size = rpart->size - (split_offset - spart->offset);
 119 +       dpart->offset = split_offset;
 120 +
 121 +       if (dpart == NULL)
 122 +               return 1;
 123 +
 124 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%llX, len=%llX \n",
 125 +               ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
 126 +
 127 +       slave = add_one_partition(master, dpart, 0, split_offset);
 128 +       if (!slave) {
 129 +               kfree(dpart);
 130 +               return -ENOMEM;
 131 +       }
 132 +       rpart->split = &slave->mtd;
 133 +
 134 +       return 0;
 135 +}
 136 +
 137 +static int refresh_rootfs_split(struct mtd_info *mtd)
 138 +{
 139 +       struct mtd_partition tpart;
 140 +       struct mtd_part *part;
 141 +       char *name;
 142 +       //int index = 0;
 143 +       int offset, size;
 144 +       int ret;
 145 +
 146 +       part = PART(mtd);
 147 +
 148 +       /* check for the new squashfs offset first */
 149 +       ret = split_squashfs(part->master, part->offset, &offset);
 150 +       if (ret)
 151 +               return ret;
 152 +
 153 +       if ((offset > 0) && !mtd->split) {
 154 +               printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
 155 +               /* if we don't have a rootfs split partition, create a new one */
 156 +               tpart.name = (char *) mtd->name;
 157 +               tpart.size = mtd->size;
 158 +               tpart.offset = part->offset;
 159 +
 160 +               return split_rootfs_data(part->master, &part->mtd, &tpart);
 161 +       } else if ((offset > 0) && mtd->split) {
 162 +               /* update the offsets of the existing partition */
 163 +               size = mtd->size + part->offset - offset;
 164 +
 165 +               part = PART(mtd->split);
 166 +               part->offset = offset;
 167 +               part->mtd.size = size;
 168 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
 169 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
 170 +                       (u32) part->offset, (u32) part->mtd.size);
 171 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 172 +               strcpy(name, ROOTFS_SPLIT_NAME);
 173 +               part->mtd.name = name;
 174 +       } else if ((offset <= 0) && mtd->split) {
 175 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
 176 +
 177 +               /* mark existing partition as removed */
 178 +               part = PART(mtd->split);
 179 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
 180 +               strcpy(name, ROOTFS_REMOVED_NAME);
 181 +               part->mtd.name = name;
 182 +               part->offset = 0;
 183 +               part->mtd.size = 0;
 184 +       }
 185 +
 186 +       return 0;
 187 +}
 188 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
 189 +
 190  /*
 191   * This function, given a master MTD object and a partition table, creates
 192   * and registers slave MTD objects which are bound to the master according to
 193 @@ -517,7 +665,7 @@ int add_mtd_partitions(struct mtd_info *
 194  {
 195         struct mtd_part *slave;
 196         uint64_t cur_offset = 0;
 197 -       int i;
 198 +       int i, ret;
 199
 200         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 201
 202 @@ -525,6 +673,21 @@ int add_mtd_partitions(struct mtd_info *
 203                 slave = add_one_partition(master, parts + i, i, cur_offset);
 204                 if (!slave)
 205                         return -ENOMEM;
 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                 cur_offset = slave->offset + slave->mtd.size;
 222         }
 223
 224 @@ -532,6 +695,32 @@ int add_mtd_partitions(struct mtd_info *
 225  }
 226  EXPORT_SYMBOL(add_mtd_partitions);
 227
 228 +int refresh_mtd_partitions(struct mtd_info *mtd)
 229 +{
 230 +       int ret = 0;
 231 +
 232 +       if (IS_PART(mtd)) {
 233 +               struct mtd_part *part;
 234 +               struct mtd_info *master;
 235 +
 236 +               part = PART(mtd);
 237 +               master = part->master;
 238 +               if (master->refresh_device)
 239 +                       ret = master->refresh_device(master);
 240 +       }
 241 +
 242 +       if (!ret && mtd->refresh_device)
 243 +               ret = mtd->refresh_device(mtd);
 244 +
 245 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 246 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
 247 +               refresh_rootfs_split(mtd);
 248 +#endif
 249 +
 250 +       return 0;
 251 +}
 252 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
 253 +
 254  static DEFINE_SPINLOCK(part_parser_lock);
 255  static LIST_HEAD(part_parsers);
 256
 257 --- a/drivers/mtd/devices/block2mtd.c
 258 +++ b/drivers/mtd/devices/block2mtd.c
 259 @@ -29,6 +29,8 @@ struct block2mtd_dev {
 260         struct block_device *blkdev;
 261         struct mtd_info mtd;
 262         struct mutex write_mutex;
 263 +       rwlock_t bdev_mutex;
 264 +       char devname[0];
 265  };
 266
 267
 268 @@ -81,6 +83,12 @@ static int block2mtd_erase(struct mtd_in
 269         size_t len = instr->len;
 270         int err;
 271
 272 +       read_lock(&dev->bdev_mutex);
 273 +       if (!dev->blkdev) {
 274 +               err = -EINVAL;
 275 +               goto done;
 276 +       }
 277 +
 278         instr->state = MTD_ERASING;
 279         mutex_lock(&dev->write_mutex);
 280         err = _block2mtd_erase(dev, from, len);
 281 @@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
 282
 283         instr->state = MTD_ERASE_DONE;
 284         mtd_erase_callback(instr);
 285 +
 286 +done:
 287 +       read_unlock(&dev->bdev_mutex);
 288 +
 289         return err;
 290  }
 291
 292 @@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
 293         struct page *page;
 294         int index = from >> PAGE_SHIFT;
 295         int offset = from & (PAGE_SIZE-1);
 296 -       int cpylen;
 297 +       int cpylen, err = 0;
 298 +
 299 +       read_lock(&dev->bdev_mutex);
 300 +       if (!dev->blkdev || (from > mtd->size)) {
 301 +               err = -EINVAL;
 302 +               goto done;
 303 +       }
 304
 305 -       if (from > mtd->size)
 306 -               return -EINVAL;
 307         if (from + len > mtd->size)
 308                 len = mtd->size - from;
 309
 310 @@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
 311                 len = len - cpylen;
 312
 313                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
 314 -               if (!page)
 315 -                       return -ENOMEM;
 316 -               if (IS_ERR(page))
 317 -                       return PTR_ERR(page);
 318 +               if (!page) {
 319 +                       err = -ENOMEM;
 320 +                       goto done;
 321 +               }
 322 +               if (IS_ERR(page)) {
 323 +                       err = PTR_ERR(page);
 324 +                       goto done;
 325 +               }
 326
 327                 memcpy(buf, page_address(page) + offset, cpylen);
 328                 page_cache_release(page);
 329 @@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
 330                 offset = 0;
 331                 index++;
 332         }
 333 -       return 0;
 334 +
 335 +done:
 336 +       read_unlock(&dev->bdev_mutex);
 337 +       return err;
 338  }
 339
 340
 341 @@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
 342                 size_t *retlen, const u_char *buf)
 343  {
 344         struct block2mtd_dev *dev = mtd->priv;
 345 -       int err;
 346 +       int err = 0;
 347 +
 348 +       read_lock(&dev->bdev_mutex);
 349 +       if (!dev->blkdev) {
 350 +               err = -EINVAL;
 351 +               goto done;
 352 +       }
 353
 354         if (!len)
 355 -               return 0;
 356 -       if (to >= mtd->size)
 357 -               return -ENOSPC;
 358 +               goto done;
 359 +
 360 +       if (to >= mtd->size) {
 361 +               err = -ENOSPC;
 362 +               goto done;
 363 +       }
 364 +
 365         if (to + len > mtd->size)
 366                 len = mtd->size - to;
 367
 368 @@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
 369         mutex_unlock(&dev->write_mutex);
 370         if (err > 0)
 371                 err = 0;
 372 +
 373 +done:
 374 +       read_unlock(&dev->bdev_mutex);
 375         return err;
 376  }
 377
 378 @@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
 379  static void block2mtd_sync(struct mtd_info *mtd)
 380  {
 381         struct block2mtd_dev *dev = mtd->priv;
 382 -       sync_blockdev(dev->blkdev);
 383 -       return;
 384 -}
 385 -
 386 -
 387 -static void block2mtd_free_device(struct block2mtd_dev *dev)
 388 -{
 389 -       if (!dev)
 390 -               return;
 391 -
 392 -       kfree(dev->mtd.name);
 393
 394 -       if (dev->blkdev) {
 395 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 396 -                                       0, -1);
 397 -               close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 398 -       }
 399 +       read_lock(&dev->bdev_mutex);
 400 +       if (dev->blkdev)
 401 +               sync_blockdev(dev->blkdev);
 402 +       read_unlock(&dev->bdev_mutex);
 403
 404 -       kfree(dev);
 405 +       return;
 406  }
 407
 408
 409 -/* FIXME: ensure that mtd->size % erase_size == 0 */
 410 -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
 411 +static int _open_bdev(struct block2mtd_dev *dev)
 412  {
 413         struct block_device *bdev;
 414 -       struct block2mtd_dev *dev;
 415 -       struct mtd_partition *part;
 416 -       char *name;
 417 -
 418 -       if (!devname)
 419 -               return NULL;
 420 -
 421 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
 422 -       if (!dev)
 423 -               return NULL;
 424
 425         /* Get a handle on the device */
 426 -       bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
 427 +       bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
 428  #ifndef MODULE
 429         if (IS_ERR(bdev)) {
 430
 431                 /* We might not have rootfs mounted at this point. Try
 432                    to resolve the device name by other means. */
 433
 434 -               dev_t devt = name_to_dev_t(devname);
 435 +               dev_t devt = name_to_dev_t(dev->devname);
 436                 if (devt) {
 437                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 438                 }
 439 @@ -263,17 +276,98 @@ static struct block2mtd_dev *add_device(
 440  #endif
 441
 442         if (IS_ERR(bdev)) {
 443 -               ERROR("error: cannot open device %s", devname);
 444 -               goto devinit_err;
 445 +               ERROR("error: cannot open device %s", dev->devname);
 446 +               return 1;
 447         }
 448         dev->blkdev = bdev;
 449
 450         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 451                 ERROR("attempting to use an MTD device as a block device");
 452 -               goto devinit_err;
 453 +               return 1;
 454         }
 455
 456 +       return 0;
 457 +}
 458 +
 459 +static void _close_bdev(struct block2mtd_dev *dev)
 460 +{
 461 +       struct block_device *bdev;
 462 +
 463 +       if (!dev->blkdev)
 464 +               return;
 465 +
 466 +       bdev = dev->blkdev;
 467 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
 468 +       close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 469 +       dev->blkdev = NULL;
 470 +}
 471 +
 472 +static void block2mtd_free_device(struct block2mtd_dev *dev)
 473 +{
 474 +       if (!dev)
 475 +               return;
 476 +
 477 +       kfree(dev->mtd.name);
 478 +       _close_bdev(dev);
 479 +       kfree(dev);
 480 +}
 481 +
 482 +
 483 +static int block2mtd_refresh(struct mtd_info *mtd)
 484 +{
 485 +       struct block2mtd_dev *dev = mtd->priv;
 486 +       struct block_device *bdev;
 487 +       dev_t devt;
 488 +       int err = 0;
 489 +
 490 +       /* no other mtd function can run at this point */
 491 +       write_lock(&dev->bdev_mutex);
 492 +
 493 +       /* get the device number for the whole disk */
 494 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
 495 +
 496 +       /* close the old block device */
 497 +       _close_bdev(dev);
 498 +
 499 +       /* open the whole disk, issue a partition rescan, then */
 500 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
 501 +       if (!bdev || !bdev->bd_disk)
 502 +               err = -EINVAL;
 503 +#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
 504 +       else
 505 +               err = rescan_partitions(bdev->bd_disk, bdev);
 506 +#endif
 507 +       if (bdev)
 508 +               close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
 509 +
 510 +       /* try to open the partition block device again */
 511 +       _open_bdev(dev);
 512 +       write_unlock(&dev->bdev_mutex);
 513 +
 514 +       return err;
 515 +}
 516 +
 517 +/* FIXME: ensure that mtd->size % erase_size == 0 */
 518 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
 519 +{
 520 +       struct block2mtd_dev *dev;
 521 +       struct mtd_partition *part;
 522 +       char *name;
 523 +
 524 +       if (!devname)
 525 +               return NULL;
 526 +
 527 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 528 +       if (!dev)
 529 +               return NULL;
 530 +
 531 +       strcpy(dev->devname, devname);
 532 +
 533 +       if (_open_bdev(dev))
 534 +               goto devinit_err;
 535 +
 536         mutex_init(&dev->write_mutex);
 537 +       rwlock_init(&dev->bdev_mutex);
 538
 539         if (!mtdname)
 540                 mtdname = devname;
 541 @@ -297,6 +391,7 @@ static struct block2mtd_dev *add_device(
 542         dev->mtd.read = block2mtd_read;
 543         dev->mtd.priv = dev;
 544         dev->mtd.owner = THIS_MODULE;
 545 +       dev->mtd.refresh_device = block2mtd_refresh;
 546
 547         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 548         part->name = dev->mtd.name;
 549 --- a/drivers/mtd/mtdchar.c
 550 +++ b/drivers/mtd/mtdchar.c
 551 @@ -18,6 +18,7 @@
 552
 553  #include <linux/mtd/mtd.h>
 554  #include <linux/mtd/compatmac.h>
 555 +#include <linux/mtd/partitions.h>
 556
 557  #include <asm/uaccess.h>
 558
 559 @@ -814,6 +815,13 @@ static int mtd_ioctl(struct inode *inode
 560                 file->f_pos = 0;
 561                 break;
 562         }
 563 +#ifdef CONFIG_MTD_PARTITIONS
 564 +       case MTDREFRESH:
 565 +       {
 566 +               ret = refresh_mtd_partitions(mtd);
 567 +               break;
 568 +       }
 569 +#endif
 570
 571         default:
 572                 ret = -ENOTTY;
 573 --- a/include/linux/mtd/mtd.h
 574 +++ b/include/linux/mtd/mtd.h
 575 @@ -101,6 +101,7 @@ struct mtd_oob_ops {
 576         uint8_t         *oobbuf;
 577  };
 578
 579 +struct mtd_info;
 580  struct mtd_info {
 581         u_char type;
 582         uint32_t flags;
 583 @@ -241,6 +242,9 @@ struct mtd_info {
 584         struct device dev;
 585         int usecount;
 586
 587 +       int (*refresh_device)(struct mtd_info *mtd);
 588 +       struct mtd_info *split;
 589 +
 590         /* If the driver is something smart, like UBI, it may need to maintain
 591          * its own reference counting. The below functions are only for driver.
 592          * The driver may register its callbacks. These callbacks are not
 593 --- a/include/linux/mtd/partitions.h
 594 +++ b/include/linux/mtd/partitions.h
 595 @@ -34,12 +34,14 @@
 596   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
 597   */
 598
 599 +struct mtd_partition;
 600  struct mtd_partition {
 601         char *name;                     /* identifier string */
 602         uint64_t size;                  /* partition size */
 603         uint64_t offset;                /* offset within the master MTD space */
 604         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
 605         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only)*/
 606 +       int (*refresh_partition)(struct mtd_info *);
 607  };
 608
 609  #define MTDPART_OFS_NXTBLK     (-2)
 610 @@ -51,6 +53,7 @@ struct mtd_info;
 611
 612  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 613  int del_mtd_partitions(struct mtd_info *);
 614 +int refresh_mtd_partitions(struct mtd_info *);
 615
 616  /*
 617   * Functions dealing with the various ways of partitioning the space
 618 --- a/include/mtd/mtd-abi.h
 619 +++ b/include/mtd/mtd-abi.h
 620 @@ -110,6 +110,7 @@ struct otp_info {
 621  #define MEMERASE64             _IOW('M', 20, struct erase_info_user64)
 622  #define MEMWRITEOOB64          _IOWR('M', 21, struct mtd_oob_buf64)
 623  #define MEMREADOOB64           _IOWR('M', 22, struct mtd_oob_buf64)
 624 +#define MTDREFRESH             _IO('M', 23)
 625
 626  /*
 627   * Obsolete legacy interface. Keep it in order not to break userspace