[kernel] generic/2.6.28: fix yaffs cvs patch
[openwrt.git] / target / linux / generic-2.6 / patches-2.6.23 / 065-rootfs_split.patch
1 --- a/drivers/mtd/Kconfig
2 +++ b/drivers/mtd/Kconfig
3 @@ -47,6 +47,16 @@
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 @@
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 @@ -308,6 +310,312 @@
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 +       slave->mtd.refresh_device = part->refresh_partition;
75 +
76 +       if(master->point && master->unpoint){
77 +               slave->mtd.point = part_point;
78 +               slave->mtd.unpoint = part_unpoint;
79 +       }
80 +
81 +       if (master->read_oob)
82 +               slave->mtd.read_oob = part_read_oob;
83 +       if (master->write_oob)
84 +               slave->mtd.write_oob = part_write_oob;
85 +       if(master->read_user_prot_reg)
86 +               slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
87 +       if(master->read_fact_prot_reg)
88 +               slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
89 +       if(master->write_user_prot_reg)
90 +               slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
91 +       if(master->lock_user_prot_reg)
92 +               slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
93 +       if(master->get_user_prot_info)
94 +               slave->mtd.get_user_prot_info = part_get_user_prot_info;
95 +       if(master->get_fact_prot_info)
96 +               slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
97 +       if (master->sync)
98 +               slave->mtd.sync = part_sync;
99 +       if (!i && master->suspend && master->resume) {
100 +                       slave->mtd.suspend = part_suspend;
101 +                       slave->mtd.resume = part_resume;
102 +       }
103 +       if (master->writev)
104 +               slave->mtd.writev = part_writev;
105 +       if (master->lock)
106 +               slave->mtd.lock = part_lock;
107 +       if (master->unlock)
108 +               slave->mtd.unlock = part_unlock;
109 +       if (master->block_isbad)
110 +               slave->mtd.block_isbad = part_block_isbad;
111 +       if (master->block_markbad)
112 +               slave->mtd.block_markbad = part_block_markbad;
113 +       slave->mtd.erase = part_erase;
114 +       slave->master = master;
115 +       slave->offset = part->offset;
116 +       slave->index = i;
117 +
118 +       if (slave->offset == MTDPART_OFS_APPEND)
119 +               slave->offset = cur_offset;
120 +       if (slave->offset == MTDPART_OFS_NXTBLK) {
121 +               slave->offset = cur_offset;
122 +               if ((cur_offset % master->erasesize) != 0) {
123 +                       /* Round up to next erasesize */
124 +                       slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
125 +                       printk(KERN_NOTICE "Moving partition %d: "
126 +                              "0x%08x -> 0x%08x\n", i,
127 +                              cur_offset, slave->offset);
128 +               }
129 +       }
130 +       if (slave->mtd.size == MTDPART_SIZ_FULL)
131 +               slave->mtd.size = master->size - slave->offset;
132 +       cur_offset = slave->offset + slave->mtd.size;
133 +
134 +       printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
135 +               slave->offset + slave->mtd.size, slave->mtd.name);
136 +
137 +       /* let's do some sanity checks */
138 +       if (slave->offset >= master->size) {
139 +                       /* let's register it anyway to preserve ordering */
140 +               slave->offset = 0;
141 +               slave->mtd.size = 0;
142 +               printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
143 +                       part->name);
144 +       }
145 +       if (slave->offset + slave->mtd.size > master->size) {
146 +               slave->mtd.size = master->size - slave->offset;
147 +               printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
148 +                       part->name, master->name, slave->mtd.size);
149 +       }
150 +       if (master->numeraseregions>1) {
151 +               /* Deal with variable erase size stuff */
152 +               int i;
153 +               struct mtd_erase_region_info *regions = master->eraseregions;
154 +
155 +               /* Find the first erase regions which is part of this partition. */
156 +               for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
157 +                       ;
158 +
159 +               for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
160 +                       if (slave->mtd.erasesize < regions[i].erasesize) {
161 +                               slave->mtd.erasesize = regions[i].erasesize;
162 +                       }
163 +               }
164 +       } else {
165 +               /* Single erase size */
166 +               slave->mtd.erasesize = master->erasesize;
167 +       }
168 +
169 +       if ((slave->mtd.flags & MTD_WRITEABLE) &&
170 +           (slave->offset % slave->mtd.erasesize)) {
171 +               /* Doesn't start on a boundary of major erase size */
172 +               /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
173 +               slave->mtd.flags &= ~MTD_WRITEABLE;
174 +               printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
175 +                       part->name);
176 +       }
177 +       if ((slave->mtd.flags & MTD_WRITEABLE) &&
178 +           (slave->mtd.size % slave->mtd.erasesize)) {
179 +               slave->mtd.flags &= ~MTD_WRITEABLE;
180 +               printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
181 +                       part->name);
182 +       }
183 +
184 +       slave->mtd.ecclayout = master->ecclayout;
185 +       if (master->block_isbad) {
186 +               uint32_t offs = 0;
187 +
188 +               while(offs < slave->mtd.size) {
189 +                       if (master->block_isbad(master,
190 +                                               offs + slave->offset))
191 +                               slave->mtd.ecc_stats.badblocks++;
192 +                       offs += slave->mtd.erasesize;
193 +               }
194 +       }
195 +
196 +       if(part->mtdp)
197 +       {       /* store the object pointer (caller may or may not register it */
198 +               *part->mtdp = &slave->mtd;
199 +               slave->registered = 0;
200 +       }
201 +       else
202 +       {
203 +               /* register our partition */
204 +               add_mtd_device(&slave->mtd);
205 +               slave->registered = 1;
206 +       }
207 +
208 +       if (slp)
209 +               *slp = slave;
210 +
211 +       return 0;
212 +}
213 +
214 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
215 +#define ROOTFS_SPLIT_NAME "rootfs_data"
216 +#define ROOTFS_REMOVED_NAME "<removed>"
217 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
218 +{
219 +       char buf[512];
220 +       struct squashfs_super_block *sb = (struct squashfs_super_block *) buf;
221 +       int len, ret;
222 +
223 +       ret = master->read(master, offset, sizeof(*sb), &len, buf);
224 +       if (ret || (len != sizeof(*sb))) {
225 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
226 +                       "from \"%s\"\n", master->name);
227 +               return -EINVAL;
228 +       }
229 +
230 +       if (*((u32 *) buf) != SQUASHFS_MAGIC) {
231 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
232 +                       master->name);
233 +               *split_offset = 0;
234 +               return 0;
235 +       }
236 +
237 +       if (sb->bytes_used <= 0) {
238 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
239 +                       master->name);
240 +               *split_offset = 0;
241 +               return 0;
242 +       }
243 +
244 +       len = (u32) sb->bytes_used;
245 +       len += (offset & 0x000fffff);
246 +       len +=  (master->erasesize - 1);
247 +       len &= ~(master->erasesize - 1);
248 +       len -= (offset & 0x000fffff);
249 +       *split_offset = offset + len;
250 +
251 +       return 0;
252 +}
253 +
254 +static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, struct mtd_partition *part,
255 +               int index)
256 +{
257 +       struct mtd_partition *dpart;
258 +       struct mtd_part *slave = NULL;
259 +       int split_offset = 0;
260 +       int ret;
261 +
262 +       ret = split_squashfs(master, part->offset, &split_offset);
263 +       if (ret)
264 +               return ret;
265 +
266 +       if (split_offset <= 0)
267 +               return 0;
268 +
269 +       dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
270 +       if (dpart == NULL) {
271 +               printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
272 +                       ROOTFS_SPLIT_NAME);
273 +               return -ENOMEM;
274 +       }
275 +
276 +       memcpy(dpart, part, sizeof(*part));
277 +       dpart->name = (unsigned char *)&dpart[1];
278 +       strcpy(dpart->name, ROOTFS_SPLIT_NAME);
279 +
280 +       dpart->size -= split_offset - dpart->offset;
281 +       dpart->offset = split_offset;
282 +
283 +       if (dpart == NULL)
284 +               return 1;
285 +
286 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%X, len=%X \n",
287 +               ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
288 +
289 +       ret = add_one_partition(master, dpart, index, &slave);
290 +       if (ret)
291 +               kfree(dpart);
292 +       else if (slave)
293 +               rpart->split = &slave->mtd;
294 +
295 +       return ret;
296 +}
297 +
298 +static int refresh_rootfs_split(struct mtd_info *mtd)
299 +{
300 +       struct mtd_partition tpart;
301 +       struct mtd_part *part;
302 +       int index = 0;
303 +       int offset, size;
304 +       int ret;
305 +
306 +       part = PART(mtd);
307 +
308 +       /* check for the new squashfs offset first */
309 +       ret = split_squashfs(part->master, part->offset, &offset);
310 +       if (ret)
311 +               return ret;
312 +
313 +       if ((offset > 0) && !mtd->split) {
314 +               printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
315 +               /* if we don't have a rootfs split partition, create a new one */
316 +               tpart.name = mtd->name;
317 +               tpart.size = mtd->size;
318 +               tpart.offset = part->offset;
319 +
320 +               /* find the index of the last partition */
321 +               if (!list_empty(&mtd_partitions))
322 +                       index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
323 +
324 +               return split_rootfs_data(part->master, &part->mtd, &tpart, index);
325 +       } else if ((offset > 0) && mtd->split) {
326 +               /* update the offsets of the existing partition */
327 +               size = mtd->size + part->offset - offset;
328 +
329 +               part = PART(mtd->split);
330 +               part->offset = offset;
331 +               part->mtd.size = size;
332 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
333 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
334 +                       part->offset, part->mtd.size);
335 +               strcpy(part->mtd.name, ROOTFS_SPLIT_NAME);
336 +       } else if ((offset <= 0) && mtd->split) {
337 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
338 +
339 +               /* mark existing partition as removed */
340 +               part = PART(mtd->split);
341 +               strcpy(part->mtd.name, ROOTFS_REMOVED_NAME);
342 +               part->offset = 0;
343 +               part->mtd.size = 0;
344 +       }
345 +
346 +       return 0;
347 +}
348 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
349 +
350  /*
351   * This function, given a master MTD object and a partition table, creates
352   * and registers slave MTD objects which are bound to the master according to
353 @@ -320,168 +628,31 @@
354                        int nbparts)
355  {
356         struct mtd_part *slave;
357 -       u_int32_t cur_offset = 0;
358 -       int i;
359 +       struct mtd_partition *part;
360 +       int i, j, ret = 0;
361  
362         printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
363  
364 -       for (i = 0; i < nbparts; i++) {
365 -
366 -               /* allocate the partition structure */
367 -               slave = kzalloc (sizeof(*slave), GFP_KERNEL);
368 -               if (!slave) {
369 -                       printk ("memory allocation error while creating partitions for \"%s\"\n",
370 -                               master->name);
371 -                       del_mtd_partitions(master);
372 -                       return -ENOMEM;
373 -               }
374 -               list_add(&slave->list, &mtd_partitions);
375 -
376 -               /* set up the MTD object for this partition */
377 -               slave->mtd.type = master->type;
378 -               slave->mtd.flags = master->flags & ~parts[i].mask_flags;
379 -               slave->mtd.size = parts[i].size;
380 -               slave->mtd.writesize = master->writesize;
381 -               slave->mtd.oobsize = master->oobsize;
382 -               slave->mtd.oobavail = master->oobavail;
383 -               slave->mtd.subpage_sft = master->subpage_sft;
384 -
385 -               slave->mtd.name = parts[i].name;
386 -               slave->mtd.owner = master->owner;
387 -
388 -               slave->mtd.read = part_read;
389 -               slave->mtd.write = part_write;
390 -
391 -               if(master->point && master->unpoint){
392 -                       slave->mtd.point = part_point;
393 -                       slave->mtd.unpoint = part_unpoint;
394 -               }
395 -
396 -               if (master->read_oob)
397 -                       slave->mtd.read_oob = part_read_oob;
398 -               if (master->write_oob)
399 -                       slave->mtd.write_oob = part_write_oob;
400 -               if(master->read_user_prot_reg)
401 -                       slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
402 -               if(master->read_fact_prot_reg)
403 -                       slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
404 -               if(master->write_user_prot_reg)
405 -                       slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
406 -               if(master->lock_user_prot_reg)
407 -                       slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
408 -               if(master->get_user_prot_info)
409 -                       slave->mtd.get_user_prot_info = part_get_user_prot_info;
410 -               if(master->get_fact_prot_info)
411 -                       slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
412 -               if (master->sync)
413 -                       slave->mtd.sync = part_sync;
414 -               if (!i && master->suspend && master->resume) {
415 -                               slave->mtd.suspend = part_suspend;
416 -                               slave->mtd.resume = part_resume;
417 -               }
418 -               if (master->writev)
419 -                       slave->mtd.writev = part_writev;
420 -               if (master->lock)
421 -                       slave->mtd.lock = part_lock;
422 -               if (master->unlock)
423 -                       slave->mtd.unlock = part_unlock;
424 -               if (master->block_isbad)
425 -                       slave->mtd.block_isbad = part_block_isbad;
426 -               if (master->block_markbad)
427 -                       slave->mtd.block_markbad = part_block_markbad;
428 -               slave->mtd.erase = part_erase;
429 -               slave->master = master;
430 -               slave->offset = parts[i].offset;
431 -               slave->index = i;
432 -
433 -               if (slave->offset == MTDPART_OFS_APPEND)
434 -                       slave->offset = cur_offset;
435 -               if (slave->offset == MTDPART_OFS_NXTBLK) {
436 -                       slave->offset = cur_offset;
437 -                       if ((cur_offset % master->erasesize) != 0) {
438 -                               /* Round up to next erasesize */
439 -                               slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
440 -                               printk(KERN_NOTICE "Moving partition %d: "
441 -                                      "0x%08x -> 0x%08x\n", i,
442 -                                      cur_offset, slave->offset);
443 -                       }
444 -               }
445 -               if (slave->mtd.size == MTDPART_SIZ_FULL)
446 -                       slave->mtd.size = master->size - slave->offset;
447 -               cur_offset = slave->offset + slave->mtd.size;
448 -
449 -               printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
450 -                       slave->offset + slave->mtd.size, slave->mtd.name);
451 -
452 -               /* let's do some sanity checks */
453 -               if (slave->offset >= master->size) {
454 -                               /* let's register it anyway to preserve ordering */
455 -                       slave->offset = 0;
456 -                       slave->mtd.size = 0;
457 -                       printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
458 -                               parts[i].name);
459 -               }
460 -               if (slave->offset + slave->mtd.size > master->size) {
461 -                       slave->mtd.size = master->size - slave->offset;
462 -                       printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
463 -                               parts[i].name, master->name, slave->mtd.size);
464 -               }
465 -               if (master->numeraseregions>1) {
466 -                       /* Deal with variable erase size stuff */
467 -                       int i;
468 -                       struct mtd_erase_region_info *regions = master->eraseregions;
469 -
470 -                       /* Find the first erase regions which is part of this partition. */
471 -                       for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
472 -                               ;
473 -
474 -                       for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
475 -                               if (slave->mtd.erasesize < regions[i].erasesize) {
476 -                                       slave->mtd.erasesize = regions[i].erasesize;
477 -                               }
478 +       for (i = 0, j = 0; i < nbparts; i++) {
479 +               part = (struct mtd_partition *) &parts[i];
480 +               ret = add_one_partition(master, part, j, &slave);
481 +               if (ret)
482 +                       return ret;
483 +               j++;
484 +
485 +               if (strcmp(part->name, "rootfs") == 0 && slave->registered) {
486 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
487 +                       if (ROOT_DEV == 0) {
488 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
489 +                                       "set to be root filesystem\n");
490 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
491                         }
492 -               } else {
493 -                       /* Single erase size */
494 -                       slave->mtd.erasesize = master->erasesize;
495 -               }
496 -
497 -               if ((slave->mtd.flags & MTD_WRITEABLE) &&
498 -                   (slave->offset % slave->mtd.erasesize)) {
499 -                       /* Doesn't start on a boundary of major erase size */
500 -                       /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
501 -                       slave->mtd.flags &= ~MTD_WRITEABLE;
502 -                       printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
503 -                               parts[i].name);
504 -               }
505 -               if ((slave->mtd.flags & MTD_WRITEABLE) &&
506 -                   (slave->mtd.size % slave->mtd.erasesize)) {
507 -                       slave->mtd.flags &= ~MTD_WRITEABLE;
508 -                       printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
509 -                               parts[i].name);
510 -               }
511 -
512 -               slave->mtd.ecclayout = master->ecclayout;
513 -               if (master->block_isbad) {
514 -                       uint32_t offs = 0;
515 -
516 -                       while(offs < slave->mtd.size) {
517 -                               if (master->block_isbad(master,
518 -                                                       offs + slave->offset))
519 -                                       slave->mtd.ecc_stats.badblocks++;
520 -                               offs += slave->mtd.erasesize;
521 -                       }
522 -               }
523 -
524 -               if(parts[i].mtdp)
525 -               {       /* store the object pointer (caller may or may not register it */
526 -                       *parts[i].mtdp = &slave->mtd;
527 -                       slave->registered = 0;
528 -               }
529 -               else
530 -               {
531 -                       /* register our partition */
532 -                       add_mtd_device(&slave->mtd);
533 -                       slave->registered = 1;
534 +#endif
535 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
536 +                       ret = split_rootfs_data(master, &slave->mtd, part, j);
537 +                       if (ret == 0)
538 +                               j++;
539 +#endif
540                 }
541         }
542  
543 @@ -557,6 +728,32 @@
544         return ret;
545  }
546  
547 +int refresh_mtd_partitions(struct mtd_info *mtd)
548 +{
549 +       int ret = 0;
550 +
551 +       if (IS_PART(mtd)) {
552 +               struct mtd_part *part;
553 +               struct mtd_info *master;
554 +
555 +               part = PART(mtd);
556 +               master = part->master;
557 +               if (master->refresh_device)
558 +                       ret = master->refresh_device(master);
559 +       }
560 +
561 +       if (!ret && mtd->refresh_device)
562 +               ret = mtd->refresh_device(mtd);
563 +
564 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
565 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
566 +               refresh_rootfs_split(mtd);
567 +#endif
568 +
569 +       return 0;
570 +}
571 +
572  EXPORT_SYMBOL_GPL(parse_mtd_partitions);
573 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
574  EXPORT_SYMBOL_GPL(register_mtd_parser);
575  EXPORT_SYMBOL_GPL(deregister_mtd_parser);
576 --- a/drivers/mtd/devices/block2mtd.c
577 +++ b/drivers/mtd/devices/block2mtd.c
578 @@ -34,6 +34,8 @@
579         struct block_device *blkdev;
580         struct mtd_info mtd;
581         struct mutex write_mutex;
582 +       rwlock_t bdev_mutex;
583 +       char devname[0];
584  };
585  
586  
587 @@ -86,6 +88,12 @@
588         size_t len = instr->len;
589         int err;
590  
591 +       read_lock(&dev->bdev_mutex);
592 +       if (!dev->blkdev) {
593 +               err = -EINVAL;
594 +               goto done;
595 +       }
596 +
597         instr->state = MTD_ERASING;
598         mutex_lock(&dev->write_mutex);
599         err = _block2mtd_erase(dev, from, len);
600 @@ -98,6 +106,10 @@
601  
602         instr->state = MTD_ERASE_DONE;
603         mtd_erase_callback(instr);
604 +
605 +done:
606 +       read_unlock(&dev->bdev_mutex);
607 +
608         return err;
609  }
610  
611 @@ -109,10 +121,14 @@
612         struct page *page;
613         int index = from >> PAGE_SHIFT;
614         int offset = from & (PAGE_SIZE-1);
615 -       int cpylen;
616 +       int cpylen, err = 0;
617 +
618 +       read_lock(&dev->bdev_mutex);
619 +       if (!dev->blkdev || (from > mtd->size)) {
620 +               err = -EINVAL;
621 +               goto done;
622 +       }
623  
624 -       if (from > mtd->size)
625 -               return -EINVAL;
626         if (from + len > mtd->size)
627                 len = mtd->size - from;
628  
629 @@ -127,10 +143,14 @@
630                 len = len - cpylen;
631  
632                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
633 -               if (!page)
634 -                       return -ENOMEM;
635 -               if (IS_ERR(page))
636 -                       return PTR_ERR(page);
637 +               if (!page) {
638 +                       err = -ENOMEM;
639 +                       goto done;
640 +               }
641 +               if (IS_ERR(page)) {
642 +                       err = PTR_ERR(page);
643 +                       goto done;
644 +               }
645  
646                 memcpy(buf, page_address(page) + offset, cpylen);
647                 page_cache_release(page);
648 @@ -141,7 +161,10 @@
649                 offset = 0;
650                 index++;
651         }
652 -       return 0;
653 +
654 +done:
655 +       read_unlock(&dev->bdev_mutex);
656 +       return err;
657  }
658  
659  
660 @@ -193,12 +216,22 @@
661                 size_t *retlen, const u_char *buf)
662  {
663         struct block2mtd_dev *dev = mtd->priv;
664 -       int err;
665 +       int err = 0;
666 +
667 +       read_lock(&dev->bdev_mutex);
668 +       if (!dev->blkdev) {
669 +               err = -EINVAL;
670 +               goto done;
671 +       }
672  
673         if (!len)
674 -               return 0;
675 -       if (to >= mtd->size)
676 -               return -ENOSPC;
677 +               goto done;
678 +
679 +       if (to >= mtd->size) {
680 +               err = -ENOSPC;
681 +               goto done;
682 +       }
683 +
684         if (to + len > mtd->size)
685                 len = mtd->size - to;
686  
687 @@ -207,6 +240,9 @@
688         mutex_unlock(&dev->write_mutex);
689         if (err > 0)
690                 err = 0;
691 +
692 +done:
693 +       read_unlock(&dev->bdev_mutex);
694         return err;
695  }
696  
697 @@ -215,51 +251,29 @@
698  static void block2mtd_sync(struct mtd_info *mtd)
699  {
700         struct block2mtd_dev *dev = mtd->priv;
701 -       sync_blockdev(dev->blkdev);
702 -       return;
703 -}
704 -
705 -
706 -static void block2mtd_free_device(struct block2mtd_dev *dev)
707 -{
708 -       if (!dev)
709 -               return;
710 -
711 -       kfree(dev->mtd.name);
712  
713 -       if (dev->blkdev) {
714 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
715 -                                       0, -1);
716 -               close_bdev_excl(dev->blkdev);
717 -       }
718 +       read_lock(&dev->bdev_mutex);
719 +       if (dev->blkdev)
720 +               sync_blockdev(dev->blkdev);
721 +       read_unlock(&dev->bdev_mutex);
722  
723 -       kfree(dev);
724 +       return;
725  }
726  
727  
728 -/* FIXME: ensure that mtd->size % erase_size == 0 */
729 -static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
730 +static int _open_bdev(struct block2mtd_dev *dev)
731  {
732         struct block_device *bdev;
733 -       struct block2mtd_dev *dev;
734 -       struct mtd_partition *part;
735 -
736 -       if (!devname)
737 -               return NULL;
738 -
739 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
740 -       if (!dev)
741 -               return NULL;
742  
743         /* Get a handle on the device */
744 -       bdev = open_bdev_excl(devname, O_RDWR, NULL);
745 +       bdev = open_bdev_excl(dev->devname, O_RDWR, NULL);
746  #ifndef MODULE
747         if (IS_ERR(bdev)) {
748  
749                 /* We might not have rootfs mounted at this point. Try
750                    to resolve the device name by other means. */
751  
752 -               dev_t devt = name_to_dev_t(devname);
753 +               dev_t devt = name_to_dev_t(dev->devname);
754                 if (devt) {
755                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
756                 }
757 @@ -267,17 +281,96 @@
758  #endif
759  
760         if (IS_ERR(bdev)) {
761 -               ERROR("error: cannot open device %s", devname);
762 -               goto devinit_err;
763 +               ERROR("error: cannot open device %s", dev->devname);
764 +               return 1;
765         }
766         dev->blkdev = bdev;
767  
768         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
769                 ERROR("attempting to use an MTD device as a block device");
770 -               goto devinit_err;
771 +               return 1;
772         }
773  
774 +       return 0;
775 +}
776 +
777 +static void _close_bdev(struct block2mtd_dev *dev)
778 +{
779 +       struct block_device *bdev;
780 +
781 +       if (!dev->blkdev)
782 +               return;
783 +
784 +       bdev = dev->blkdev;
785 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
786 +       close_bdev_excl(dev->blkdev);
787 +       dev->blkdev = NULL;
788 +}
789 +
790 +static void block2mtd_free_device(struct block2mtd_dev *dev)
791 +{
792 +       if (!dev)
793 +               return;
794 +
795 +       kfree(dev->mtd.name);
796 +       _close_bdev(dev);
797 +       kfree(dev);
798 +}
799 +
800 +
801 +static int block2mtd_refresh(struct mtd_info *mtd)
802 +{
803 +       struct block2mtd_dev *dev = mtd->priv;
804 +       struct block_device *bdev;
805 +       dev_t devt;
806 +       int err = 0;
807 +
808 +       /* no other mtd function can run at this point */
809 +       write_lock(&dev->bdev_mutex);
810 +
811 +       /* get the device number for the whole disk */
812 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
813 +
814 +       /* close the old block device */
815 +       _close_bdev(dev);
816 +
817 +       /* open the whole disk, issue a partition rescan, then */
818 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
819 +       if (!bdev || !bdev->bd_disk)
820 +               err = -EINVAL;
821 +       else {
822 +               err = rescan_partitions(bdev->bd_disk, bdev);
823 +       }
824 +       if (bdev)
825 +               close_bdev_excl(bdev);
826 +
827 +       /* try to open the partition block device again */
828 +       _open_bdev(dev);
829 +       write_unlock(&dev->bdev_mutex);
830 +
831 +       return err;
832 +}
833 +
834 +/* FIXME: ensure that mtd->size % erase_size == 0 */
835 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
836 +{
837 +       struct block2mtd_dev *dev;
838 +       struct mtd_partition *part;
839 +
840 +       if (!devname)
841 +               return NULL;
842 +
843 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
844 +       if (!dev)
845 +               return NULL;
846 +
847 +       strcpy(dev->devname, devname);
848 +
849 +       if (_open_bdev(dev))
850 +               goto devinit_err;
851 +
852         mutex_init(&dev->write_mutex);
853 +       rwlock_init(&dev->bdev_mutex);
854  
855         /* Setup the MTD structure */
856         /* make the name contain the block device in */
857 @@ -304,6 +397,7 @@
858         dev->mtd.read = block2mtd_read;
859         dev->mtd.priv = dev;
860         dev->mtd.owner = THIS_MODULE;
861 +       dev->mtd.refresh_device = block2mtd_refresh;
862         
863         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
864         part->name = dev->mtd.name;
865 --- a/drivers/mtd/mtdchar.c
866 +++ b/drivers/mtd/mtdchar.c
867 @@ -17,6 +17,7 @@
868  
869  #include <linux/mtd/mtd.h>
870  #include <linux/mtd/compatmac.h>
871 +#include <linux/mtd/partitions.h>
872  
873  #include <asm/uaccess.h>
874  
875 @@ -753,6 +754,13 @@
876                 file->f_pos = 0;
877                 break;
878         }
879 +#ifdef CONFIG_MTD_PARTITIONS
880 +       case MTDREFRESH:
881 +       {
882 +               ret = refresh_mtd_partitions(mtd);
883 +               break;
884 +       }
885 +#endif
886  
887         default:
888                 ret = -ENOTTY;
889 --- a/include/linux/mtd/mtd.h
890 +++ b/include/linux/mtd/mtd.h
891 @@ -98,6 +98,7 @@
892         uint8_t         *oobbuf;
893  };
894  
895 +struct mtd_info;
896  struct mtd_info {
897         u_char type;
898         u_int32_t flags;
899 @@ -195,6 +196,9 @@
900         struct module *owner;
901         int usecount;
902  
903 +       int (*refresh_device)(struct mtd_info *mtd);
904 +       struct mtd_info *split;
905 +
906         /* If the driver is something smart, like UBI, it may need to maintain
907          * its own reference counting. The below functions are only for driver.
908          * The driver may register its callbacks. These callbacks are not
909 --- a/include/linux/mtd/partitions.h
910 +++ b/include/linux/mtd/partitions.h
911 @@ -36,6 +36,7 @@
912   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
913   */
914  
915 +struct mtd_partition;
916  struct mtd_partition {
917         char *name;                     /* identifier string */
918         u_int32_t size;                 /* partition size */
919 @@ -43,6 +44,7 @@
920         u_int32_t mask_flags;           /* master MTD flags to mask out for this partition */
921         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only)*/
922         struct mtd_info **mtdp;         /* pointer to store the MTD object */
923 +       int (*refresh_partition)(struct mtd_info *);
924  };
925  
926  #define MTDPART_OFS_NXTBLK     (-2)
927 @@ -52,6 +54,7 @@
928  
929  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
930  int del_mtd_partitions(struct mtd_info *);
931 +int refresh_mtd_partitions(struct mtd_info *);
932  
933  /*
934   * Functions dealing with the various ways of partitioning the space
935 --- a/include/mtd/mtd-abi.h
936 +++ b/include/mtd/mtd-abi.h
937 @@ -95,6 +95,7 @@
938  #define ECCGETLAYOUT           _IOR('M', 17, struct nand_ecclayout)
939  #define ECCGETSTATS            _IOR('M', 18, struct mtd_ecc_stats)
940  #define MTDFILEMODE            _IO('M', 19)
941 +#define MTDREFRESH             _IO('M', 23)
942  
943  /*
944   * Obsolete legacy interface. Keep it in order not to break userspace