rename target/linux/generic-2.6 to generic
[15.05/openwrt.git] / target / linux / generic / patches-2.6.25 / 065-rootfs_split.patch
1 --- a/drivers/mtd/Kconfig
2 +++ b/drivers/mtd/Kconfig
3 @@ -47,6 +47,16 @@ 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 @@ -20,6 +20,8 @@
23  #include <linux/mtd/mtd.h>
24  #include <linux/mtd/partitions.h>
25  #include <linux/mtd/compatmac.h>
26 +#include <linux/squashfs_fs.h>
27 +#include <linux/root_dev.h>
28  
29  /* Our partition linked list */
30  static LIST_HEAD(mtd_partitions);
31 @@ -39,7 +41,7 @@ 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 @@ -322,6 +324,316 @@ int del_mtd_partitions(struct mtd_info *
41         return 0;
42  }
43  
44 +static u_int32_t cur_offset = 0;
45 +static int add_one_partition(struct mtd_info *master, const struct mtd_partition *part,
46 +               int i, struct mtd_part **slp)
47 +{
48 +       struct mtd_part *slave;
49 +
50 +       /* allocate the partition structure */
51 +       slave = kzalloc (sizeof(*slave), GFP_KERNEL);
52 +       if (!slave) {
53 +               printk ("memory allocation error while creating partitions for \"%s\"\n",
54 +                       master->name);
55 +               del_mtd_partitions(master);
56 +               return -ENOMEM;
57 +       }
58 +       list_add(&slave->list, &mtd_partitions);
59 +
60 +       /* set up the MTD object for this partition */
61 +       slave->mtd.type = master->type;
62 +       slave->mtd.flags = master->flags & ~part->mask_flags;
63 +       slave->mtd.size = part->size;
64 +       slave->mtd.writesize = master->writesize;
65 +       slave->mtd.oobsize = master->oobsize;
66 +       slave->mtd.oobavail = master->oobavail;
67 +       slave->mtd.subpage_sft = master->subpage_sft;
68 +
69 +       slave->mtd.name = part->name;
70 +       slave->mtd.owner = master->owner;
71 +
72 +       slave->mtd.read = part_read;
73 +       slave->mtd.write = part_write;
74 +
75 +       if (master->panic_write)
76 +               slave->mtd.panic_write = part_panic_write;
77 +
78 +       slave->mtd.refresh_device = part->refresh_partition;
79 +
80 +       if(master->point && master->unpoint){
81 +               slave->mtd.point = part_point;
82 +               slave->mtd.unpoint = part_unpoint;
83 +       }
84 +
85 +       if (master->read_oob)
86 +               slave->mtd.read_oob = part_read_oob;
87 +       if (master->write_oob)
88 +               slave->mtd.write_oob = part_write_oob;
89 +       if(master->read_user_prot_reg)
90 +               slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
91 +       if(master->read_fact_prot_reg)
92 +               slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
93 +       if(master->write_user_prot_reg)
94 +               slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
95 +       if(master->lock_user_prot_reg)
96 +               slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
97 +       if(master->get_user_prot_info)
98 +               slave->mtd.get_user_prot_info = part_get_user_prot_info;
99 +       if(master->get_fact_prot_info)
100 +               slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
101 +       if (master->sync)
102 +               slave->mtd.sync = part_sync;
103 +       if (!i && master->suspend && master->resume) {
104 +                       slave->mtd.suspend = part_suspend;
105 +                       slave->mtd.resume = part_resume;
106 +       }
107 +       if (master->writev)
108 +               slave->mtd.writev = part_writev;
109 +       if (master->lock)
110 +               slave->mtd.lock = part_lock;
111 +       if (master->unlock)
112 +               slave->mtd.unlock = part_unlock;
113 +       if (master->block_isbad)
114 +               slave->mtd.block_isbad = part_block_isbad;
115 +       if (master->block_markbad)
116 +               slave->mtd.block_markbad = part_block_markbad;
117 +       slave->mtd.erase = part_erase;
118 +       slave->master = master;
119 +       slave->offset = part->offset;
120 +       slave->index = i;
121 +
122 +       if (slave->offset == MTDPART_OFS_APPEND)
123 +               slave->offset = cur_offset;
124 +       if (slave->offset == MTDPART_OFS_NXTBLK) {
125 +               slave->offset = cur_offset;
126 +               if ((cur_offset % master->erasesize) != 0) {
127 +                       /* Round up to next erasesize */
128 +                       slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
129 +                       printk(KERN_NOTICE "Moving partition %d: "
130 +                              "0x%08x -> 0x%08x\n", i,
131 +                              cur_offset, slave->offset);
132 +               }
133 +       }
134 +       if (slave->mtd.size == MTDPART_SIZ_FULL)
135 +               slave->mtd.size = master->size - slave->offset;
136 +       cur_offset = slave->offset + slave->mtd.size;
137 +
138 +       printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
139 +               slave->offset + slave->mtd.size, slave->mtd.name);
140 +
141 +       /* let's do some sanity checks */
142 +       if (slave->offset >= master->size) {
143 +                       /* let's register it anyway to preserve ordering */
144 +               slave->offset = 0;
145 +               slave->mtd.size = 0;
146 +               printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
147 +                       part->name);
148 +       }
149 +       if (slave->offset + slave->mtd.size > master->size) {
150 +               slave->mtd.size = master->size - slave->offset;
151 +               printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
152 +                       part->name, master->name, slave->mtd.size);
153 +       }
154 +       if (master->numeraseregions>1) {
155 +               /* Deal with variable erase size stuff */
156 +               int i;
157 +               struct mtd_erase_region_info *regions = master->eraseregions;
158 +
159 +               /* Find the first erase regions which is part of this partition. */
160 +               for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
161 +                       ;
162 +
163 +               for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
164 +                       if (slave->mtd.erasesize < regions[i].erasesize) {
165 +                               slave->mtd.erasesize = regions[i].erasesize;
166 +                       }
167 +               }
168 +       } else {
169 +               /* Single erase size */
170 +               slave->mtd.erasesize = master->erasesize;
171 +       }
172 +
173 +       if ((slave->mtd.flags & MTD_WRITEABLE) &&
174 +           (slave->offset % slave->mtd.erasesize)) {
175 +               /* Doesn't start on a boundary of major erase size */
176 +               /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
177 +               slave->mtd.flags &= ~MTD_WRITEABLE;
178 +               printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
179 +                       part->name);
180 +       }
181 +       if ((slave->mtd.flags & MTD_WRITEABLE) &&
182 +           (slave->mtd.size % slave->mtd.erasesize)) {
183 +               slave->mtd.flags &= ~MTD_WRITEABLE;
184 +               printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
185 +                       part->name);
186 +       }
187 +
188 +       slave->mtd.ecclayout = master->ecclayout;
189 +       if (master->block_isbad) {
190 +               uint32_t offs = 0;
191 +
192 +               while(offs < slave->mtd.size) {
193 +                       if (master->block_isbad(master,
194 +                                               offs + slave->offset))
195 +                               slave->mtd.ecc_stats.badblocks++;
196 +                       offs += slave->mtd.erasesize;
197 +               }
198 +       }
199 +
200 +       if(part->mtdp)
201 +       {       /* store the object pointer (caller may or may not register it */
202 +               *part->mtdp = &slave->mtd;
203 +               slave->registered = 0;
204 +       }
205 +       else
206 +       {
207 +               /* register our partition */
208 +               add_mtd_device(&slave->mtd);
209 +               slave->registered = 1;
210 +       }
211 +
212 +       if (slp)
213 +               *slp = slave;
214 +
215 +       return 0;
216 +}
217 +
218 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
219 +#define ROOTFS_SPLIT_NAME "rootfs_data"
220 +#define ROOTFS_REMOVED_NAME "<removed>"
221 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
222 +{
223 +       char buf[512];
224 +       struct squashfs_super_block *sb = (struct squashfs_super_block *) buf;
225 +       int len, ret;
226 +
227 +       ret = master->read(master, offset, sizeof(*sb), &len, buf);
228 +       if (ret || (len != sizeof(*sb))) {
229 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
230 +                       "from \"%s\"\n", master->name);
231 +               return -EINVAL;
232 +       }
233 +
234 +       if (*((u32 *) buf) != SQUASHFS_MAGIC) {
235 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
236 +                       master->name);
237 +               *split_offset = 0;
238 +               return 0;
239 +       }
240 +
241 +       if (sb->bytes_used <= 0) {
242 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
243 +                       master->name);
244 +               *split_offset = 0;
245 +               return 0;
246 +       }
247 +
248 +       len = (u32) sb->bytes_used;
249 +       len += (offset & 0x000fffff);
250 +       len +=  (master->erasesize - 1);
251 +       len &= ~(master->erasesize - 1);
252 +       len -= (offset & 0x000fffff);
253 +       *split_offset = offset + len;
254 +
255 +       return 0;
256 +}
257 +
258 +static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, struct mtd_partition *part,
259 +               int index)
260 +{
261 +       struct mtd_partition *dpart;
262 +       struct mtd_part *slave = NULL;
263 +       int split_offset = 0;
264 +       int ret;
265 +
266 +       ret = split_squashfs(master, part->offset, &split_offset);
267 +       if (ret)
268 +               return ret;
269 +
270 +       if (split_offset <= 0)
271 +               return 0;
272 +
273 +       dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
274 +       if (dpart == NULL) {
275 +               printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
276 +                       ROOTFS_SPLIT_NAME);
277 +               return -ENOMEM;
278 +       }
279 +
280 +       memcpy(dpart, part, sizeof(*part));
281 +       dpart->name = (unsigned char *)&dpart[1];
282 +       strcpy(dpart->name, ROOTFS_SPLIT_NAME);
283 +
284 +       dpart->size -= split_offset - dpart->offset;
285 +       dpart->offset = split_offset;
286 +
287 +       if (dpart == NULL)
288 +               return 1;
289 +
290 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%X, len=%X \n",
291 +               ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
292 +
293 +       ret = add_one_partition(master, dpart, index, &slave);
294 +       if (ret)
295 +               kfree(dpart);
296 +       else if (slave)
297 +               rpart->split = &slave->mtd;
298 +
299 +       return ret;
300 +}
301 +
302 +static int refresh_rootfs_split(struct mtd_info *mtd)
303 +{
304 +       struct mtd_partition tpart;
305 +       struct mtd_part *part;
306 +       int index = 0;
307 +       int offset, size;
308 +       int ret;
309 +
310 +       part = PART(mtd);
311 +
312 +       /* check for the new squashfs offset first */
313 +       ret = split_squashfs(part->master, part->offset, &offset);
314 +       if (ret)
315 +               return ret;
316 +
317 +       if ((offset > 0) && !mtd->split) {
318 +               printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
319 +               /* if we don't have a rootfs split partition, create a new one */
320 +               tpart.name = mtd->name;
321 +               tpart.size = mtd->size;
322 +               tpart.offset = part->offset;
323 +
324 +               /* find the index of the last partition */
325 +               if (!list_empty(&mtd_partitions))
326 +                       index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
327 +
328 +               return split_rootfs_data(part->master, &part->mtd, &tpart, index);
329 +       } else if ((offset > 0) && mtd->split) {
330 +               /* update the offsets of the existing partition */
331 +               size = mtd->size + part->offset - offset;
332 +
333 +               part = PART(mtd->split);
334 +               part->offset = offset;
335 +               part->mtd.size = size;
336 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
337 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
338 +                       part->offset, part->mtd.size);
339 +               strcpy(part->mtd.name, ROOTFS_SPLIT_NAME);
340 +       } else if ((offset <= 0) && mtd->split) {
341 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
342 +
343 +               /* mark existing partition as removed */
344 +               part = PART(mtd->split);
345 +               strcpy(part->mtd.name, ROOTFS_REMOVED_NAME);
346 +               part->offset = 0;
347 +               part->mtd.size = 0;
348 +       }
349 +
350 +       return 0;
351 +}
352 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
353 +
354  /*
355   * This function, given a master MTD object and a partition table, creates
356   * and registers slave MTD objects which are bound to the master according to
357 @@ -334,171 +646,31 @@ int add_mtd_partitions(struct mtd_info *
358                        int nbparts)
359  {
360         struct mtd_part *slave;
361 -       u_int32_t cur_offset = 0;
362 -       int i;
363 +       struct mtd_partition *part;
364 +       int i, j, ret = 0;
365  
366         printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
367  
368 -       for (i = 0; i < nbparts; i++) {
369 -
370 -               /* allocate the partition structure */
371 -               slave = kzalloc (sizeof(*slave), GFP_KERNEL);
372 -               if (!slave) {
373 -                       printk ("memory allocation error while creating partitions for \"%s\"\n",
374 -                               master->name);
375 -                       del_mtd_partitions(master);
376 -                       return -ENOMEM;
377 -               }
378 -               list_add(&slave->list, &mtd_partitions);
379 -
380 -               /* set up the MTD object for this partition */
381 -               slave->mtd.type = master->type;
382 -               slave->mtd.flags = master->flags & ~parts[i].mask_flags;
383 -               slave->mtd.size = parts[i].size;
384 -               slave->mtd.writesize = master->writesize;
385 -               slave->mtd.oobsize = master->oobsize;
386 -               slave->mtd.oobavail = master->oobavail;
387 -               slave->mtd.subpage_sft = master->subpage_sft;
388 -
389 -               slave->mtd.name = parts[i].name;
390 -               slave->mtd.owner = master->owner;
391 -
392 -               slave->mtd.read = part_read;
393 -               slave->mtd.write = part_write;
394 -
395 -               if (master->panic_write)
396 -                       slave->mtd.panic_write = part_panic_write;
397 -
398 -               if(master->point && master->unpoint){
399 -                       slave->mtd.point = part_point;
400 -                       slave->mtd.unpoint = part_unpoint;
401 -               }
402 -
403 -               if (master->read_oob)
404 -                       slave->mtd.read_oob = part_read_oob;
405 -               if (master->write_oob)
406 -                       slave->mtd.write_oob = part_write_oob;
407 -               if(master->read_user_prot_reg)
408 -                       slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
409 -               if(master->read_fact_prot_reg)
410 -                       slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
411 -               if(master->write_user_prot_reg)
412 -                       slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
413 -               if(master->lock_user_prot_reg)
414 -                       slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
415 -               if(master->get_user_prot_info)
416 -                       slave->mtd.get_user_prot_info = part_get_user_prot_info;
417 -               if(master->get_fact_prot_info)
418 -                       slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
419 -               if (master->sync)
420 -                       slave->mtd.sync = part_sync;
421 -               if (!i && master->suspend && master->resume) {
422 -                               slave->mtd.suspend = part_suspend;
423 -                               slave->mtd.resume = part_resume;
424 -               }
425 -               if (master->writev)
426 -                       slave->mtd.writev = part_writev;
427 -               if (master->lock)
428 -                       slave->mtd.lock = part_lock;
429 -               if (master->unlock)
430 -                       slave->mtd.unlock = part_unlock;
431 -               if (master->block_isbad)
432 -                       slave->mtd.block_isbad = part_block_isbad;
433 -               if (master->block_markbad)
434 -                       slave->mtd.block_markbad = part_block_markbad;
435 -               slave->mtd.erase = part_erase;
436 -               slave->master = master;
437 -               slave->offset = parts[i].offset;
438 -               slave->index = i;
439 -
440 -               if (slave->offset == MTDPART_OFS_APPEND)
441 -                       slave->offset = cur_offset;
442 -               if (slave->offset == MTDPART_OFS_NXTBLK) {
443 -                       slave->offset = cur_offset;
444 -                       if ((cur_offset % master->erasesize) != 0) {
445 -                               /* Round up to next erasesize */
446 -                               slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
447 -                               printk(KERN_NOTICE "Moving partition %d: "
448 -                                      "0x%08x -> 0x%08x\n", i,
449 -                                      cur_offset, slave->offset);
450 -                       }
451 -               }
452 -               if (slave->mtd.size == MTDPART_SIZ_FULL)
453 -                       slave->mtd.size = master->size - slave->offset;
454 -               cur_offset = slave->offset + slave->mtd.size;
455 -
456 -               printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
457 -                       slave->offset + slave->mtd.size, slave->mtd.name);
458 -
459 -               /* let's do some sanity checks */
460 -               if (slave->offset >= master->size) {
461 -                               /* let's register it anyway to preserve ordering */
462 -                       slave->offset = 0;
463 -                       slave->mtd.size = 0;
464 -                       printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
465 -                               parts[i].name);
466 -               }
467 -               if (slave->offset + slave->mtd.size > master->size) {
468 -                       slave->mtd.size = master->size - slave->offset;
469 -                       printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
470 -                               parts[i].name, master->name, slave->mtd.size);
471 -               }
472 -               if (master->numeraseregions>1) {
473 -                       /* Deal with variable erase size stuff */
474 -                       int i;
475 -                       struct mtd_erase_region_info *regions = master->eraseregions;
476 -
477 -                       /* Find the first erase regions which is part of this partition. */
478 -                       for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
479 -                               ;
480 -
481 -                       for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
482 -                               if (slave->mtd.erasesize < regions[i].erasesize) {
483 -                                       slave->mtd.erasesize = regions[i].erasesize;
484 -                               }
485 +       for (i = 0, j = 0; i < nbparts; i++) {
486 +               part = (struct mtd_partition *) &parts[i];
487 +               ret = add_one_partition(master, part, j, &slave);
488 +               if (ret)
489 +                       return ret;
490 +               j++;
491 +
492 +               if (strcmp(part->name, "rootfs") == 0 && slave->registered) {
493 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
494 +                       if (ROOT_DEV == 0) {
495 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
496 +                                       "set to be root filesystem\n");
497 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
498                         }
499 -               } else {
500 -                       /* Single erase size */
501 -                       slave->mtd.erasesize = master->erasesize;
502 -               }
503 -
504 -               if ((slave->mtd.flags & MTD_WRITEABLE) &&
505 -                   (slave->offset % slave->mtd.erasesize)) {
506 -                       /* Doesn't start on a boundary of major erase size */
507 -                       /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
508 -                       slave->mtd.flags &= ~MTD_WRITEABLE;
509 -                       printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
510 -                               parts[i].name);
511 -               }
512 -               if ((slave->mtd.flags & MTD_WRITEABLE) &&
513 -                   (slave->mtd.size % slave->mtd.erasesize)) {
514 -                       slave->mtd.flags &= ~MTD_WRITEABLE;
515 -                       printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
516 -                               parts[i].name);
517 -               }
518 -
519 -               slave->mtd.ecclayout = master->ecclayout;
520 -               if (master->block_isbad) {
521 -                       uint32_t offs = 0;
522 -
523 -                       while(offs < slave->mtd.size) {
524 -                               if (master->block_isbad(master,
525 -                                                       offs + slave->offset))
526 -                                       slave->mtd.ecc_stats.badblocks++;
527 -                               offs += slave->mtd.erasesize;
528 -                       }
529 -               }
530 -
531 -               if(parts[i].mtdp)
532 -               {       /* store the object pointer (caller may or may not register it */
533 -                       *parts[i].mtdp = &slave->mtd;
534 -                       slave->registered = 0;
535 -               }
536 -               else
537 -               {
538 -                       /* register our partition */
539 -                       add_mtd_device(&slave->mtd);
540 -                       slave->registered = 1;
541 +#endif
542 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
543 +                       ret = split_rootfs_data(master, &slave->mtd, part, j);
544 +                       if (ret == 0)
545 +                               j++;
546 +#endif
547                 }
548         }
549  
550 @@ -574,6 +746,32 @@ int parse_mtd_partitions(struct mtd_info
551         return ret;
552  }
553  
554 +int refresh_mtd_partitions(struct mtd_info *mtd)
555 +{
556 +       int ret = 0;
557 +
558 +       if (IS_PART(mtd)) {
559 +               struct mtd_part *part;
560 +               struct mtd_info *master;
561 +
562 +               part = PART(mtd);
563 +               master = part->master;
564 +               if (master->refresh_device)
565 +                       ret = master->refresh_device(master);
566 +       }
567 +
568 +       if (!ret && mtd->refresh_device)
569 +               ret = mtd->refresh_device(mtd);
570 +
571 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
572 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
573 +               refresh_rootfs_split(mtd);
574 +#endif
575 +
576 +       return 0;
577 +}
578 +
579  EXPORT_SYMBOL_GPL(parse_mtd_partitions);
580 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
581  EXPORT_SYMBOL_GPL(register_mtd_parser);
582  EXPORT_SYMBOL_GPL(deregister_mtd_parser);
583 --- a/drivers/mtd/devices/block2mtd.c
584 +++ b/drivers/mtd/devices/block2mtd.c
585 @@ -34,6 +34,8 @@ struct block2mtd_dev {
586         struct block_device *blkdev;
587         struct mtd_info mtd;
588         struct mutex write_mutex;
589 +       rwlock_t bdev_mutex;
590 +       char devname[0];
591  };
592  
593  
594 @@ -86,6 +88,12 @@ static int block2mtd_erase(struct mtd_in
595         size_t len = instr->len;
596         int err;
597  
598 +       read_lock(&dev->bdev_mutex);
599 +       if (!dev->blkdev) {
600 +               err = -EINVAL;
601 +               goto done;
602 +       }
603 +
604         instr->state = MTD_ERASING;
605         mutex_lock(&dev->write_mutex);
606         err = _block2mtd_erase(dev, from, len);
607 @@ -98,6 +106,10 @@ static int block2mtd_erase(struct mtd_in
608  
609         instr->state = MTD_ERASE_DONE;
610         mtd_erase_callback(instr);
611 +
612 +done:
613 +       read_unlock(&dev->bdev_mutex);
614 +
615         return err;
616  }
617  
618 @@ -109,10 +121,14 @@ static int block2mtd_read(struct mtd_inf
619         struct page *page;
620         int index = from >> PAGE_SHIFT;
621         int offset = from & (PAGE_SIZE-1);
622 -       int cpylen;
623 +       int cpylen, err = 0;
624 +
625 +       read_lock(&dev->bdev_mutex);
626 +       if (!dev->blkdev || (from > mtd->size)) {
627 +               err = -EINVAL;
628 +               goto done;
629 +       }
630  
631 -       if (from > mtd->size)
632 -               return -EINVAL;
633         if (from + len > mtd->size)
634                 len = mtd->size - from;
635  
636 @@ -127,10 +143,14 @@ static int block2mtd_read(struct mtd_inf
637                 len = len - cpylen;
638  
639                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
640 -               if (!page)
641 -                       return -ENOMEM;
642 -               if (IS_ERR(page))
643 -                       return PTR_ERR(page);
644 +               if (!page) {
645 +                       err = -ENOMEM;
646 +                       goto done;
647 +               }
648 +               if (IS_ERR(page)) {
649 +                       err = PTR_ERR(page);
650 +                       goto done;
651 +               }
652  
653                 memcpy(buf, page_address(page) + offset, cpylen);
654                 page_cache_release(page);
655 @@ -141,7 +161,10 @@ static int block2mtd_read(struct mtd_inf
656                 offset = 0;
657                 index++;
658         }
659 -       return 0;
660 +
661 +done:
662 +       read_unlock(&dev->bdev_mutex);
663 +       return err;
664  }
665  
666  
667 @@ -193,12 +216,22 @@ static int block2mtd_write(struct mtd_in
668                 size_t *retlen, const u_char *buf)
669  {
670         struct block2mtd_dev *dev = mtd->priv;
671 -       int err;
672 +       int err = 0;
673 +
674 +       read_lock(&dev->bdev_mutex);
675 +       if (!dev->blkdev) {
676 +               err = -EINVAL;
677 +               goto done;
678 +       }
679  
680         if (!len)
681 -               return 0;
682 -       if (to >= mtd->size)
683 -               return -ENOSPC;
684 +               goto done;
685 +
686 +       if (to >= mtd->size) {
687 +               err = -ENOSPC;
688 +               goto done;
689 +       }
690 +
691         if (to + len > mtd->size)
692                 len = mtd->size - to;
693  
694 @@ -207,6 +240,9 @@ static int block2mtd_write(struct mtd_in
695         mutex_unlock(&dev->write_mutex);
696         if (err > 0)
697                 err = 0;
698 +
699 +done:
700 +       read_unlock(&dev->bdev_mutex);
701         return err;
702  }
703  
704 @@ -215,51 +251,29 @@ static int block2mtd_write(struct mtd_in
705  static void block2mtd_sync(struct mtd_info *mtd)
706  {
707         struct block2mtd_dev *dev = mtd->priv;
708 -       sync_blockdev(dev->blkdev);
709 -       return;
710 -}
711 -
712 -
713 -static void block2mtd_free_device(struct block2mtd_dev *dev)
714 -{
715 -       if (!dev)
716 -               return;
717 -
718 -       kfree(dev->mtd.name);
719  
720 -       if (dev->blkdev) {
721 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
722 -                                       0, -1);
723 -               close_bdev_excl(dev->blkdev);
724 -       }
725 +       read_lock(&dev->bdev_mutex);
726 +       if (dev->blkdev)
727 +               sync_blockdev(dev->blkdev);
728 +       read_unlock(&dev->bdev_mutex);
729  
730 -       kfree(dev);
731 +       return;
732  }
733  
734  
735 -/* FIXME: ensure that mtd->size % erase_size == 0 */
736 -static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
737 +static int _open_bdev(struct block2mtd_dev *dev)
738  {
739         struct block_device *bdev;
740 -       struct block2mtd_dev *dev;
741 -       struct mtd_partition *part;
742 -
743 -       if (!devname)
744 -               return NULL;
745 -
746 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
747 -       if (!dev)
748 -               return NULL;
749  
750         /* Get a handle on the device */
751 -       bdev = open_bdev_excl(devname, O_RDWR, NULL);
752 +       bdev = open_bdev_excl(dev->devname, O_RDWR, NULL);
753  #ifndef MODULE
754         if (IS_ERR(bdev)) {
755  
756                 /* We might not have rootfs mounted at this point. Try
757                    to resolve the device name by other means. */
758  
759 -               dev_t devt = name_to_dev_t(devname);
760 +               dev_t devt = name_to_dev_t(dev->devname);
761                 if (devt) {
762                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
763                 }
764 @@ -267,17 +281,96 @@ static struct block2mtd_dev *add_device(
765  #endif
766  
767         if (IS_ERR(bdev)) {
768 -               ERROR("error: cannot open device %s", devname);
769 -               goto devinit_err;
770 +               ERROR("error: cannot open device %s", dev->devname);
771 +               return 1;
772         }
773         dev->blkdev = bdev;
774  
775         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
776                 ERROR("attempting to use an MTD device as a block device");
777 -               goto devinit_err;
778 +               return 1;
779         }
780  
781 +       return 0;
782 +}
783 +
784 +static void _close_bdev(struct block2mtd_dev *dev)
785 +{
786 +       struct block_device *bdev;
787 +
788 +       if (!dev->blkdev)
789 +               return;
790 +
791 +       bdev = dev->blkdev;
792 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
793 +       close_bdev_excl(dev->blkdev);
794 +       dev->blkdev = NULL;
795 +}
796 +
797 +static void block2mtd_free_device(struct block2mtd_dev *dev)
798 +{
799 +       if (!dev)
800 +               return;
801 +
802 +       kfree(dev->mtd.name);
803 +       _close_bdev(dev);
804 +       kfree(dev);
805 +}
806 +
807 +
808 +static int block2mtd_refresh(struct mtd_info *mtd)
809 +{
810 +       struct block2mtd_dev *dev = mtd->priv;
811 +       struct block_device *bdev;
812 +       dev_t devt;
813 +       int err = 0;
814 +
815 +       /* no other mtd function can run at this point */
816 +       write_lock(&dev->bdev_mutex);
817 +
818 +       /* get the device number for the whole disk */
819 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
820 +
821 +       /* close the old block device */
822 +       _close_bdev(dev);
823 +
824 +       /* open the whole disk, issue a partition rescan, then */
825 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
826 +       if (!bdev || !bdev->bd_disk)
827 +               err = -EINVAL;
828 +       else {
829 +               err = rescan_partitions(bdev->bd_disk, bdev);
830 +       }
831 +       if (bdev)
832 +               close_bdev_excl(bdev);
833 +
834 +       /* try to open the partition block device again */
835 +       _open_bdev(dev);
836 +       write_unlock(&dev->bdev_mutex);
837 +
838 +       return err;
839 +}
840 +
841 +/* FIXME: ensure that mtd->size % erase_size == 0 */
842 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
843 +{
844 +       struct block2mtd_dev *dev;
845 +       struct mtd_partition *part;
846 +
847 +       if (!devname)
848 +               return NULL;
849 +
850 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
851 +       if (!dev)
852 +               return NULL;
853 +
854 +       strcpy(dev->devname, devname);
855 +
856 +       if (_open_bdev(dev))
857 +               goto devinit_err;
858 +
859         mutex_init(&dev->write_mutex);
860 +       rwlock_init(&dev->bdev_mutex);
861  
862         /* Setup the MTD structure */
863         /* make the name contain the block device in */
864 @@ -304,6 +397,7 @@ static struct block2mtd_dev *add_device(
865         dev->mtd.read = block2mtd_read;
866         dev->mtd.priv = dev;
867         dev->mtd.owner = THIS_MODULE;
868 +       dev->mtd.refresh_device = block2mtd_refresh;
869         
870         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
871         part->name = dev->mtd.name;
872 --- a/drivers/mtd/mtdchar.c
873 +++ b/drivers/mtd/mtdchar.c
874 @@ -17,6 +17,7 @@
875  
876  #include <linux/mtd/mtd.h>
877  #include <linux/mtd/compatmac.h>
878 +#include <linux/mtd/partitions.h>
879  
880  #include <asm/uaccess.h>
881  
882 @@ -756,6 +757,13 @@ static int mtd_ioctl(struct inode *inode
883                 file->f_pos = 0;
884                 break;
885         }
886 +#ifdef CONFIG_MTD_PARTITIONS
887 +       case MTDREFRESH:
888 +       {
889 +               ret = refresh_mtd_partitions(mtd);
890 +               break;
891 +       }
892 +#endif
893  
894         default:
895                 ret = -ENOTTY;
896 --- a/include/linux/mtd/mtd.h
897 +++ b/include/linux/mtd/mtd.h
898 @@ -98,6 +98,7 @@ struct mtd_oob_ops {
899         uint8_t         *oobbuf;
900  };
901  
902 +struct mtd_info;
903  struct mtd_info {
904         u_char type;
905         u_int32_t flags;
906 @@ -211,6 +212,9 @@ struct mtd_info {
907         struct module *owner;
908         int usecount;
909  
910 +       int (*refresh_device)(struct mtd_info *mtd);
911 +       struct mtd_info *split;
912 +
913         /* If the driver is something smart, like UBI, it may need to maintain
914          * its own reference counting. The below functions are only for driver.
915          * The driver may register its callbacks. These callbacks are not
916 --- a/include/linux/mtd/partitions.h
917 +++ b/include/linux/mtd/partitions.h
918 @@ -36,6 +36,7 @@
919   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
920   */
921  
922 +struct mtd_partition;
923  struct mtd_partition {
924         char *name;                     /* identifier string */
925         u_int32_t size;                 /* partition size */
926 @@ -43,6 +44,7 @@ struct mtd_partition {
927         u_int32_t mask_flags;           /* master MTD flags to mask out for this partition */
928         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only)*/
929         struct mtd_info **mtdp;         /* pointer to store the MTD object */
930 +       int (*refresh_partition)(struct mtd_info *);
931  };
932  
933  #define MTDPART_OFS_NXTBLK     (-2)
934 @@ -52,6 +54,7 @@ struct mtd_partition {
935  
936  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
937  int del_mtd_partitions(struct mtd_info *);
938 +int refresh_mtd_partitions(struct mtd_info *);
939  
940  /*
941   * Functions dealing with the various ways of partitioning the space
942 --- a/include/mtd/mtd-abi.h
943 +++ b/include/mtd/mtd-abi.h
944 @@ -95,6 +95,7 @@ struct otp_info {
945  #define ECCGETLAYOUT           _IOR('M', 17, struct nand_ecclayout)
946  #define ECCGETSTATS            _IOR('M', 18, struct mtd_ecc_stats)
947  #define MTDFILEMODE            _IO('M', 19)
948 +#define MTDREFRESH             _IO('M', 23)
949  
950  /*
951   * Obsolete legacy interface. Keep it in order not to break userspace