[kernel] revert 15922 - add back 2.6.29 kernel support
[openwrt.git] / target / linux / generic-2.6 / patches-2.6.29 / 065-rootfs_split.patch
1 --- a/drivers/mtd/Kconfig
2 +++ b/drivers/mtd/Kconfig
3 @@ -53,6 +53,16 @@ config MTD_TESTS
4           should normally be compiled as kernel modules. The modules perform
5           various checks and verifications when loaded.
6  
7 +config MTD_ROOTFS_ROOT_DEV
8 +       bool "Automatically set 'rootfs' partition to be root filesystem"
9 +       depends on MTD_PARTITIONS
10 +       default y
11 +
12 +config MTD_ROOTFS_SPLIT
13 +       bool "Automatically split 'rootfs' partition for squashfs"
14 +       depends on MTD_PARTITIONS
15 +       default y
16 +
17  config MTD_REDBOOT_PARTS
18         tristate "RedBoot partition table parsing"
19         depends on MTD_PARTITIONS
20 --- a/drivers/mtd/mtdpart.c
21 +++ b/drivers/mtd/mtdpart.c
22 @@ -18,6 +18,8 @@
23  #include <linux/mtd/mtd.h>
24  #include <linux/mtd/partitions.h>
25  #include <linux/mtd/compatmac.h>
26 +#include <linux/root_dev.h>
27 +#include <linux/magic.h>
28  
29  /* Our partition linked list */
30  static LIST_HEAD(mtd_partitions);
31 @@ -37,7 +39,7 @@ struct mtd_part {
32   * the pointer to that structure with this macro.
33   */
34  #define PART(x)  ((struct mtd_part *)(x))
35 -
36 +#define IS_PART(mtd) (mtd->read == part_read)
37  
38  /*
39   * MTD methods which simply translate the effective address and pass through
40 @@ -489,6 +491,156 @@ 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 +       char buf[512];
58 +       struct squashfs_super_block *sb = (struct squashfs_super_block *) buf;
59 +       int len, ret;
60 +
61 +       ret = master->read(master, offset, sizeof(*sb), &len, buf);
62 +       if (ret || (len != sizeof(*sb))) {
63 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
64 +                       "from \"%s\"\n", master->name);
65 +               return -EINVAL;
66 +       }
67 +
68 +       if (*((u32 *) buf) != SQUASHFS_MAGIC) {
69 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
70 +                       master->name);
71 +               *split_offset = 0;
72 +               return 0;
73 +       }
74 +
75 +       if (sb->bytes_used <= 0) {
76 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
77 +                       master->name);
78 +               *split_offset = 0;
79 +               return 0;
80 +       }
81 +
82 +       len = (u32) sb->bytes_used;
83 +       len += (offset & 0x000fffff);
84 +       len +=  (master->erasesize - 1);
85 +       len &= ~(master->erasesize - 1);
86 +       len -= (offset & 0x000fffff);
87 +       *split_offset = offset + len;
88 +
89 +       return 0;
90 +}
91 +
92 +static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, const struct mtd_partition *part,
93 +               int index)
94 +{
95 +       struct mtd_partition *dpart;
96 +       struct mtd_part *slave = NULL;
97 +       int split_offset = 0;
98 +       int ret;
99 +
100 +       ret = split_squashfs(master, part->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 -= split_offset - dpart->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, index, 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 +               /* find the index of the last partition */
161 +               if (!list_empty(&mtd_partitions))
162 +                       index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
163 +
164 +               return split_rootfs_data(part->master, &part->mtd, &tpart, index);
165 +       } else if ((offset > 0) && mtd->split) {
166 +               /* update the offsets of the existing partition */
167 +               size = mtd->size + part->offset - offset;
168 +
169 +               part = PART(mtd->split);
170 +               part->offset = offset;
171 +               part->mtd.size = size;
172 +               printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
173 +                       __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
174 +                       (u32) part->offset, (u32) part->mtd.size);
175 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
176 +               strcpy(name, ROOTFS_SPLIT_NAME);
177 +               part->mtd.name = name;
178 +       } else if ((offset <= 0) && mtd->split) {
179 +               printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
180 +
181 +               /* mark existing partition as removed */
182 +               part = PART(mtd->split);
183 +               name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
184 +               strcpy(name, ROOTFS_REMOVED_NAME);
185 +               part->mtd.name = name;
186 +               part->offset = 0;
187 +               part->mtd.size = 0;
188 +       }
189 +
190 +       return 0;
191 +}
192 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
193 +
194  /*
195   * This function, given a master MTD object and a partition table, creates
196   * and registers slave MTD objects which are bound to the master according to
197 @@ -502,14 +654,29 @@ int add_mtd_partitions(struct mtd_info *
198  {
199         struct mtd_part *slave;
200         uint64_t cur_offset = 0;
201 -       int i;
202 +       int i, j, ret;
203  
204         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
205  
206 -       for (i = 0; i < nbparts; i++) {
207 -               slave = add_one_partition(master, parts + i, i, cur_offset);
208 +       for (i = 0, j = 0; i < nbparts; i++) {
209 +               slave = add_one_partition(master, parts + i, j++, cur_offset);
210                 if (!slave)
211                         return -ENOMEM;
212 +
213 +               if (!strcmp(parts[i].name, "rootfs") && slave->registered) {
214 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
215 +                       if (ROOT_DEV == 0) {
216 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
217 +                                       "set to be root filesystem\n");
218 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
219 +                       }
220 +#endif
221 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
222 +                       ret = split_rootfs_data(master, &slave->mtd, &parts[i], j);
223 +                       if (ret == 0)
224 +                               j++;
225 +#endif
226 +               }
227                 cur_offset = slave->offset + slave->mtd.size;
228         }
229  
230 @@ -517,6 +684,32 @@ int add_mtd_partitions(struct mtd_info *
231  }
232  EXPORT_SYMBOL(add_mtd_partitions);
233  
234 +int refresh_mtd_partitions(struct mtd_info *mtd)
235 +{
236 +       int ret = 0;
237 +
238 +       if (IS_PART(mtd)) {
239 +               struct mtd_part *part;
240 +               struct mtd_info *master;
241 +
242 +               part = PART(mtd);
243 +               master = part->master;
244 +               if (master->refresh_device)
245 +                       ret = master->refresh_device(master);
246 +       }
247 +
248 +       if (!ret && mtd->refresh_device)
249 +               ret = mtd->refresh_device(mtd);
250 +
251 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
252 +       if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
253 +               refresh_rootfs_split(mtd);
254 +#endif
255 +
256 +       return 0;
257 +}
258 +EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
259 +
260  static DEFINE_SPINLOCK(part_parser_lock);
261  static LIST_HEAD(part_parsers);
262  
263 --- a/drivers/mtd/devices/block2mtd.c
264 +++ b/drivers/mtd/devices/block2mtd.c
265 @@ -29,6 +29,8 @@ struct block2mtd_dev {
266         struct block_device *blkdev;
267         struct mtd_info mtd;
268         struct mutex write_mutex;
269 +       rwlock_t bdev_mutex;
270 +       char devname[0];
271  };
272  
273  
274 @@ -81,6 +83,12 @@ static int block2mtd_erase(struct mtd_in
275         size_t len = instr->len;
276         int err;
277  
278 +       read_lock(&dev->bdev_mutex);
279 +       if (!dev->blkdev) {
280 +               err = -EINVAL;
281 +               goto done;
282 +       }
283 +
284         instr->state = MTD_ERASING;
285         mutex_lock(&dev->write_mutex);
286         err = _block2mtd_erase(dev, from, len);
287 @@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
288  
289         instr->state = MTD_ERASE_DONE;
290         mtd_erase_callback(instr);
291 +
292 +done:
293 +       read_unlock(&dev->bdev_mutex);
294 +
295         return err;
296  }
297  
298 @@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
299         struct page *page;
300         int index = from >> PAGE_SHIFT;
301         int offset = from & (PAGE_SIZE-1);
302 -       int cpylen;
303 +       int cpylen, err = 0;
304 +
305 +       read_lock(&dev->bdev_mutex);
306 +       if (!dev->blkdev || (from > mtd->size)) {
307 +               err = -EINVAL;
308 +               goto done;
309 +       }
310  
311 -       if (from > mtd->size)
312 -               return -EINVAL;
313         if (from + len > mtd->size)
314                 len = mtd->size - from;
315  
316 @@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
317                 len = len - cpylen;
318  
319                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
320 -               if (!page)
321 -                       return -ENOMEM;
322 -               if (IS_ERR(page))
323 -                       return PTR_ERR(page);
324 +               if (!page) {
325 +                       err = -ENOMEM;
326 +                       goto done;
327 +               }
328 +               if (IS_ERR(page)) {
329 +                       err = PTR_ERR(page);
330 +                       goto done;
331 +               }
332  
333                 memcpy(buf, page_address(page) + offset, cpylen);
334                 page_cache_release(page);
335 @@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
336                 offset = 0;
337                 index++;
338         }
339 -       return 0;
340 +
341 +done:
342 +       read_unlock(&dev->bdev_mutex);
343 +       return err;
344  }
345  
346  
347 @@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
348                 size_t *retlen, const u_char *buf)
349  {
350         struct block2mtd_dev *dev = mtd->priv;
351 -       int err;
352 +       int err = 0;
353 +
354 +       read_lock(&dev->bdev_mutex);
355 +       if (!dev->blkdev) {
356 +               err = -EINVAL;
357 +               goto done;
358 +       }
359  
360         if (!len)
361 -               return 0;
362 -       if (to >= mtd->size)
363 -               return -ENOSPC;
364 +               goto done;
365 +
366 +       if (to >= mtd->size) {
367 +               err = -ENOSPC;
368 +               goto done;
369 +       }
370 +
371         if (to + len > mtd->size)
372                 len = mtd->size - to;
373  
374 @@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
375         mutex_unlock(&dev->write_mutex);
376         if (err > 0)
377                 err = 0;
378 +
379 +done:
380 +       read_unlock(&dev->bdev_mutex);
381         return err;
382  }
383  
384 @@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
385  static void block2mtd_sync(struct mtd_info *mtd)
386  {
387         struct block2mtd_dev *dev = mtd->priv;
388 -       sync_blockdev(dev->blkdev);
389 -       return;
390 -}
391 -
392 -
393 -static void block2mtd_free_device(struct block2mtd_dev *dev)
394 -{
395 -       if (!dev)
396 -               return;
397 -
398 -       kfree(dev->mtd.name);
399  
400 -       if (dev->blkdev) {
401 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
402 -                                       0, -1);
403 -               close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
404 -       }
405 +       read_lock(&dev->bdev_mutex);
406 +       if (dev->blkdev)
407 +               sync_blockdev(dev->blkdev);
408 +       read_unlock(&dev->bdev_mutex);
409  
410 -       kfree(dev);
411 +       return;
412  }
413  
414  
415 -/* FIXME: ensure that mtd->size % erase_size == 0 */
416 -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
417 +static int _open_bdev(struct block2mtd_dev *dev)
418  {
419         struct block_device *bdev;
420 -       struct block2mtd_dev *dev;
421 -       struct mtd_partition *part;
422 -       char *name;
423 -
424 -       if (!devname)
425 -               return NULL;
426 -
427 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
428 -       if (!dev)
429 -               return NULL;
430  
431         /* Get a handle on the device */
432 -       bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
433 +       bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
434  #ifndef MODULE
435         if (IS_ERR(bdev)) {
436  
437                 /* We might not have rootfs mounted at this point. Try
438                    to resolve the device name by other means. */
439  
440 -               dev_t devt = name_to_dev_t(devname);
441 +               dev_t devt = name_to_dev_t(dev->devname);
442                 if (devt) {
443                         bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
444                 }
445 @@ -263,17 +276,97 @@ static struct block2mtd_dev *add_device(
446  #endif
447  
448         if (IS_ERR(bdev)) {
449 -               ERROR("error: cannot open device %s", devname);
450 -               goto devinit_err;
451 +               ERROR("error: cannot open device %s", dev->devname);
452 +               return 1;
453         }
454         dev->blkdev = bdev;
455  
456         if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
457                 ERROR("attempting to use an MTD device as a block device");
458 -               goto devinit_err;
459 +               return 1;
460         }
461  
462 +       return 0;
463 +}
464 +
465 +static void _close_bdev(struct block2mtd_dev *dev)
466 +{
467 +       struct block_device *bdev;
468 +
469 +       if (!dev->blkdev)
470 +               return;
471 +
472 +       bdev = dev->blkdev;
473 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
474 +       close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
475 +       dev->blkdev = NULL;
476 +}
477 +
478 +static void block2mtd_free_device(struct block2mtd_dev *dev)
479 +{
480 +       if (!dev)
481 +               return;
482 +
483 +       kfree(dev->mtd.name);
484 +       _close_bdev(dev);
485 +       kfree(dev);
486 +}
487 +
488 +
489 +static int block2mtd_refresh(struct mtd_info *mtd)
490 +{
491 +       struct block2mtd_dev *dev = mtd->priv;
492 +       struct block_device *bdev;
493 +       dev_t devt;
494 +       int err = 0;
495 +
496 +       /* no other mtd function can run at this point */
497 +       write_lock(&dev->bdev_mutex);
498 +
499 +       /* get the device number for the whole disk */
500 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
501 +
502 +       /* close the old block device */
503 +       _close_bdev(dev);
504 +
505 +       /* open the whole disk, issue a partition rescan, then */
506 +       bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
507 +       if (!bdev || !bdev->bd_disk)
508 +               err = -EINVAL;
509 +       else {
510 +               err = rescan_partitions(bdev->bd_disk, bdev);
511 +       }
512 +       if (bdev)
513 +               close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
514 +
515 +       /* try to open the partition block device again */
516 +       _open_bdev(dev);
517 +       write_unlock(&dev->bdev_mutex);
518 +
519 +       return err;
520 +}
521 +
522 +/* FIXME: ensure that mtd->size % erase_size == 0 */
523 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
524 +{
525 +       struct block2mtd_dev *dev;
526 +       struct mtd_partition *part;
527 +       char *name;
528 +
529 +       if (!devname)
530 +               return NULL;
531 +
532 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
533 +       if (!dev)
534 +               return NULL;
535 +
536 +       strcpy(dev->devname, devname);
537 +
538 +       if (_open_bdev(dev))
539 +               goto devinit_err;
540 +
541         mutex_init(&dev->write_mutex);
542 +       rwlock_init(&dev->bdev_mutex);
543  
544         if (!mtdname)
545                 mtdname = devname;
546 @@ -297,6 +390,7 @@ static struct block2mtd_dev *add_device(
547         dev->mtd.read = block2mtd_read;
548         dev->mtd.priv = dev;
549         dev->mtd.owner = THIS_MODULE;
550 +       dev->mtd.refresh_device = block2mtd_refresh;
551  
552         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
553         part->name = dev->mtd.name;
554 --- a/drivers/mtd/mtdchar.c
555 +++ b/drivers/mtd/mtdchar.c
556 @@ -16,6 +16,7 @@
557  
558  #include <linux/mtd/mtd.h>
559  #include <linux/mtd/compatmac.h>
560 +#include <linux/mtd/partitions.h>
561  
562  #include <asm/uaccess.h>
563  
564 @@ -773,6 +774,13 @@ static int mtd_ioctl(struct inode *inode
565                 file->f_pos = 0;
566                 break;
567         }
568 +#ifdef CONFIG_MTD_PARTITIONS
569 +       case MTDREFRESH:
570 +       {
571 +               ret = refresh_mtd_partitions(mtd);
572 +               break;
573 +       }
574 +#endif
575  
576         default:
577                 ret = -ENOTTY;
578 --- a/include/linux/mtd/mtd.h
579 +++ b/include/linux/mtd/mtd.h
580 @@ -100,6 +100,7 @@ struct mtd_oob_ops {
581         uint8_t         *oobbuf;
582  };
583  
584 +struct mtd_info;
585  struct mtd_info {
586         u_char type;
587         uint32_t flags;
588 @@ -225,6 +226,9 @@ struct mtd_info {
589         struct module *owner;
590         int usecount;
591  
592 +       int (*refresh_device)(struct mtd_info *mtd);
593 +       struct mtd_info *split;
594 +
595         /* If the driver is something smart, like UBI, it may need to maintain
596          * its own reference counting. The below functions are only for driver.
597          * The driver may register its callbacks. These callbacks are not
598 --- a/include/linux/mtd/partitions.h
599 +++ b/include/linux/mtd/partitions.h
600 @@ -34,6 +34,7 @@
601   * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
602   */
603  
604 +struct mtd_partition;
605  struct mtd_partition {
606         char *name;                     /* identifier string */
607         uint64_t size;                  /* partition size */
608 @@ -41,6 +42,7 @@ struct mtd_partition {
609         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
610         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only)*/
611         struct mtd_info **mtdp;         /* pointer to store the MTD object */
612 +       int (*refresh_partition)(struct mtd_info *);
613  };
614  
615  #define MTDPART_OFS_NXTBLK     (-2)
616 @@ -50,6 +52,7 @@ struct mtd_partition {
617  
618  int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
619  int del_mtd_partitions(struct mtd_info *);
620 +int refresh_mtd_partitions(struct mtd_info *);
621  
622  /*
623   * Functions dealing with the various ways of partitioning the space
624 --- a/include/mtd/mtd-abi.h
625 +++ b/include/mtd/mtd-abi.h
626 @@ -93,6 +93,7 @@ struct otp_info {
627  #define ECCGETLAYOUT           _IOR('M', 17, struct nand_ecclayout)
628  #define ECCGETSTATS            _IOR('M', 18, struct mtd_ecc_stats)
629  #define MTDFILEMODE            _IO('M', 19)
630 +#define MTDREFRESH             _IO('M', 23)
631  
632  /*
633   * Obsolete legacy interface. Keep it in order not to break userspace