Root/target/linux/generic/patches-2.6.30/065-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@@ -512,6 +514,157 @@ out_register:
41     return slave;
42 }
43 
44+#ifdef CONFIG_MTD_ROOTFS_SPLIT
45+#define ROOTFS_SPLIT_NAME "rootfs_data"
46+#define ROOTFS_REMOVED_NAME "<removed>"
47+
48+struct squashfs_super_block {
49+ __le32 s_magic;
50+ __le32 pad0[9];
51+ __le64 bytes_used;
52+};
53+
54+
55+static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
56+{
57+ struct squashfs_super_block sb;
58+ int len, ret;
59+
60+ ret = master->read(master, offset, sizeof(sb), &len, (void *) &sb);
61+ if (ret || (len != sizeof(sb))) {
62+ printk(KERN_ALERT "split_squashfs: error occured while reading "
63+ "from \"%s\"\n", master->name);
64+ return -EINVAL;
65+ }
66+
67+ if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
68+ printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
69+ master->name);
70+ *split_offset = 0;
71+ return 0;
72+ }
73+
74+ if (le64_to_cpu((sb.bytes_used)) <= 0) {
75+ printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
76+ master->name);
77+ *split_offset = 0;
78+ return 0;
79+ }
80+
81+ len = (u32) le64_to_cpu(sb.bytes_used);
82+ len += (offset & 0x000fffff);
83+ len += (master->erasesize - 1);
84+ len &= ~(master->erasesize - 1);
85+ len -= (offset & 0x000fffff);
86+ *split_offset = offset + len;
87+
88+ return 0;
89+}
90+
91+static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, const struct mtd_partition *part,
92+ int index)
93+{
94+ struct mtd_partition *dpart;
95+ struct mtd_part *slave = NULL;
96+ struct mtd_part *spart;
97+ int split_offset = 0;
98+ int ret;
99+
100+ spart = PART(rpart);
101+ ret = split_squashfs(master, spart->offset, &split_offset);
102+ if (ret)
103+ return ret;
104+
105+ if (split_offset <= 0)
106+ return 0;
107+
108+ dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
109+ if (dpart == NULL) {
110+ printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
111+ ROOTFS_SPLIT_NAME);
112+ return -ENOMEM;
113+ }
114+
115+ memcpy(dpart, part, sizeof(*part));
116+ dpart->name = (unsigned char *)&dpart[1];
117+ strcpy(dpart->name, ROOTFS_SPLIT_NAME);
118+
119+ dpart->size = rpart->size - (split_offset - spart->offset);
120+ dpart->offset = split_offset;
121+
122+ if (dpart == NULL)
123+ return 1;
124+
125+ printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%llX, len=%llX \n",
126+ ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
127+
128+ slave = add_one_partition(master, dpart, index, split_offset);
129+ if (!slave) {
130+ kfree(dpart);
131+ return -ENOMEM;
132+ }
133+ rpart->split = &slave->mtd;
134+
135+ return 0;
136+}
137+
138+static int refresh_rootfs_split(struct mtd_info *mtd)
139+{
140+ struct mtd_partition tpart;
141+ struct mtd_part *part;
142+ char *name;
143+ int index = 0;
144+ int offset, size;
145+ int ret;
146+
147+ part = PART(mtd);
148+
149+ /* check for the new squashfs offset first */
150+ ret = split_squashfs(part->master, part->offset, &offset);
151+ if (ret)
152+ return ret;
153+
154+ if ((offset > 0) && !mtd->split) {
155+ printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
156+ /* if we don't have a rootfs split partition, create a new one */
157+ tpart.name = (char *) mtd->name;
158+ tpart.size = mtd->size;
159+ tpart.offset = part->offset;
160+
161+ /* find the index of the last partition */
162+ if (!list_empty(&mtd_partitions))
163+ index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
164+
165+ return split_rootfs_data(part->master, &part->mtd, &tpart, index);
166+ } else if ((offset > 0) && mtd->split) {
167+ /* update the offsets of the existing partition */
168+ size = mtd->size + part->offset - offset;
169+
170+ part = PART(mtd->split);
171+ part->offset = offset;
172+ part->mtd.size = size;
173+ printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
174+ __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
175+ (u32) part->offset, (u32) part->mtd.size);
176+ name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
177+ strcpy(name, ROOTFS_SPLIT_NAME);
178+ part->mtd.name = name;
179+ } else if ((offset <= 0) && mtd->split) {
180+ printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
181+
182+ /* mark existing partition as removed */
183+ part = PART(mtd->split);
184+ name = kmalloc(sizeof(ROOTFS_SPLIT_NAME) + 1, GFP_KERNEL);
185+ strcpy(name, ROOTFS_REMOVED_NAME);
186+ part->mtd.name = name;
187+ part->offset = 0;
188+ part->mtd.size = 0;
189+ }
190+
191+ return 0;
192+}
193+#endif /* CONFIG_MTD_ROOTFS_SPLIT */
194+
195 /*
196  * This function, given a master MTD object and a partition table, creates
197  * and registers slave MTD objects which are bound to the master according to
198@@ -527,14 +680,29 @@ int add_mtd_partitions(struct mtd_info *
199 {
200     struct mtd_part *slave;
201     uint64_t cur_offset = 0;
202- int i;
203+ int i, j, ret;
204 
205     printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
206 
207- for (i = 0; i < nbparts; i++) {
208- slave = add_one_partition(master, parts + i, i, cur_offset);
209+ for (i = 0, j = 0; i < nbparts; i++) {
210+ slave = add_one_partition(master, parts + i, j++, cur_offset);
211         if (!slave)
212             return -ENOMEM;
213+
214+ if (!strcmp(parts[i].name, "rootfs") && slave->registered) {
215+#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
216+ if (ROOT_DEV == 0) {
217+ printk(KERN_NOTICE "mtd: partition \"rootfs\" "
218+ "set to be root filesystem\n");
219+ ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
220+ }
221+#endif
222+#ifdef CONFIG_MTD_ROOTFS_SPLIT
223+ ret = split_rootfs_data(master, &slave->mtd, &parts[i], j);
224+ if (ret == 0)
225+ j++;
226+#endif
227+ }
228         cur_offset = slave->offset + slave->mtd.size;
229     }
230 
231@@ -542,6 +710,32 @@ int add_mtd_partitions(struct mtd_info *
232 }
233 EXPORT_SYMBOL(add_mtd_partitions);
234 
235+int refresh_mtd_partitions(struct mtd_info *mtd)
236+{
237+ int ret = 0;
238+
239+ if (IS_PART(mtd)) {
240+ struct mtd_part *part;
241+ struct mtd_info *master;
242+
243+ part = PART(mtd);
244+ master = part->master;
245+ if (master->refresh_device)
246+ ret = master->refresh_device(master);
247+ }
248+
249+ if (!ret && mtd->refresh_device)
250+ ret = mtd->refresh_device(mtd);
251+
252+#ifdef CONFIG_MTD_ROOTFS_SPLIT
253+ if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
254+ refresh_rootfs_split(mtd);
255+#endif
256+
257+ return 0;
258+}
259+EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
260+
261 static DEFINE_SPINLOCK(part_parser_lock);
262 static LIST_HEAD(part_parsers);
263 
264--- a/drivers/mtd/devices/block2mtd.c
265+++ b/drivers/mtd/devices/block2mtd.c
266@@ -29,6 +29,8 @@ struct block2mtd_dev {
267     struct block_device *blkdev;
268     struct mtd_info mtd;
269     struct mutex write_mutex;
270+ rwlock_t bdev_mutex;
271+ char devname[0];
272 };
273 
274 
275@@ -81,6 +83,12 @@ static int block2mtd_erase(struct mtd_in
276     size_t len = instr->len;
277     int err;
278 
279+ read_lock(&dev->bdev_mutex);
280+ if (!dev->blkdev) {
281+ err = -EINVAL;
282+ goto done;
283+ }
284+
285     instr->state = MTD_ERASING;
286     mutex_lock(&dev->write_mutex);
287     err = _block2mtd_erase(dev, from, len);
288@@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
289 
290     instr->state = MTD_ERASE_DONE;
291     mtd_erase_callback(instr);
292+
293+done:
294+ read_unlock(&dev->bdev_mutex);
295+
296     return err;
297 }
298 
299@@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
300     struct page *page;
301     int index = from >> PAGE_SHIFT;
302     int offset = from & (PAGE_SIZE-1);
303- int cpylen;
304+ int cpylen, err = 0;
305+
306+ read_lock(&dev->bdev_mutex);
307+ if (!dev->blkdev || (from > mtd->size)) {
308+ err = -EINVAL;
309+ goto done;
310+ }
311 
312- if (from > mtd->size)
313- return -EINVAL;
314     if (from + len > mtd->size)
315         len = mtd->size - from;
316 
317@@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
318         len = len - cpylen;
319 
320         page = page_read(dev->blkdev->bd_inode->i_mapping, index);
321- if (!page)
322- return -ENOMEM;
323- if (IS_ERR(page))
324- return PTR_ERR(page);
325+ if (!page) {
326+ err = -ENOMEM;
327+ goto done;
328+ }
329+ if (IS_ERR(page)) {
330+ err = PTR_ERR(page);
331+ goto done;
332+ }
333 
334         memcpy(buf, page_address(page) + offset, cpylen);
335         page_cache_release(page);
336@@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
337         offset = 0;
338         index++;
339     }
340- return 0;
341+
342+done:
343+ read_unlock(&dev->bdev_mutex);
344+ return err;
345 }
346 
347 
348@@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
349         size_t *retlen, const u_char *buf)
350 {
351     struct block2mtd_dev *dev = mtd->priv;
352- int err;
353+ int err = 0;
354+
355+ read_lock(&dev->bdev_mutex);
356+ if (!dev->blkdev) {
357+ err = -EINVAL;
358+ goto done;
359+ }
360 
361     if (!len)
362- return 0;
363- if (to >= mtd->size)
364- return -ENOSPC;
365+ goto done;
366+
367+ if (to >= mtd->size) {
368+ err = -ENOSPC;
369+ goto done;
370+ }
371+
372     if (to + len > mtd->size)
373         len = mtd->size - to;
374 
375@@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
376     mutex_unlock(&dev->write_mutex);
377     if (err > 0)
378         err = 0;
379+
380+done:
381+ read_unlock(&dev->bdev_mutex);
382     return err;
383 }
384 
385@@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
386 static void block2mtd_sync(struct mtd_info *mtd)
387 {
388     struct block2mtd_dev *dev = mtd->priv;
389- sync_blockdev(dev->blkdev);
390- return;
391-}
392-
393-
394-static void block2mtd_free_device(struct block2mtd_dev *dev)
395-{
396- if (!dev)
397- return;
398-
399- kfree(dev->mtd.name);
400 
401- if (dev->blkdev) {
402- invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
403- 0, -1);
404- close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
405- }
406+ read_lock(&dev->bdev_mutex);
407+ if (dev->blkdev)
408+ sync_blockdev(dev->blkdev);
409+ read_unlock(&dev->bdev_mutex);
410 
411- kfree(dev);
412+ return;
413 }
414 
415 
416-/* FIXME: ensure that mtd->size % erase_size == 0 */
417-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
418+static int _open_bdev(struct block2mtd_dev *dev)
419 {
420     struct block_device *bdev;
421- struct block2mtd_dev *dev;
422- struct mtd_partition *part;
423- char *name;
424-
425- if (!devname)
426- return NULL;
427-
428- dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
429- if (!dev)
430- return NULL;
431 
432     /* Get a handle on the device */
433- bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
434+ bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
435 #ifndef MODULE
436     if (IS_ERR(bdev)) {
437 
438         /* We might not have rootfs mounted at this point. Try
439            to resolve the device name by other means. */
440 
441- dev_t devt = name_to_dev_t(devname);
442+ dev_t devt = name_to_dev_t(dev->devname);
443         if (devt) {
444             bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
445         }
446@@ -263,17 +276,98 @@ static struct block2mtd_dev *add_device(
447 #endif
448 
449     if (IS_ERR(bdev)) {
450- ERROR("error: cannot open device %s", devname);
451- goto devinit_err;
452+ ERROR("error: cannot open device %s", dev->devname);
453+ return 1;
454     }
455     dev->blkdev = bdev;
456 
457     if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
458         ERROR("attempting to use an MTD device as a block device");
459- goto devinit_err;
460+ return 1;
461     }
462 
463+ return 0;
464+}
465+
466+static void _close_bdev(struct block2mtd_dev *dev)
467+{
468+ struct block_device *bdev;
469+
470+ if (!dev->blkdev)
471+ return;
472+
473+ bdev = dev->blkdev;
474+ invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
475+ close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
476+ dev->blkdev = NULL;
477+}
478+
479+static void block2mtd_free_device(struct block2mtd_dev *dev)
480+{
481+ if (!dev)
482+ return;
483+
484+ kfree(dev->mtd.name);
485+ _close_bdev(dev);
486+ kfree(dev);
487+}
488+
489+
490+static int block2mtd_refresh(struct mtd_info *mtd)
491+{
492+ struct block2mtd_dev *dev = mtd->priv;
493+ struct block_device *bdev;
494+ dev_t devt;
495+ int err = 0;
496+
497+ /* no other mtd function can run at this point */
498+ write_lock(&dev->bdev_mutex);
499+
500+ /* get the device number for the whole disk */
501+ devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
502+
503+ /* close the old block device */
504+ _close_bdev(dev);
505+
506+ /* open the whole disk, issue a partition rescan, then */
507+ bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
508+ if (!bdev || !bdev->bd_disk)
509+ err = -EINVAL;
510+#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
511+ else
512+ err = rescan_partitions(bdev->bd_disk, bdev);
513+#endif
514+ if (bdev)
515+ close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
516+
517+ /* try to open the partition block device again */
518+ _open_bdev(dev);
519+ write_unlock(&dev->bdev_mutex);
520+
521+ return err;
522+}
523+
524+/* FIXME: ensure that mtd->size % erase_size == 0 */
525+static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
526+{
527+ struct block2mtd_dev *dev;
528+ struct mtd_partition *part;
529+ char *name;
530+
531+ if (!devname)
532+ return NULL;
533+
534+ dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
535+ if (!dev)
536+ return NULL;
537+
538+ strcpy(dev->devname, devname);
539+
540+ if (_open_bdev(dev))
541+ goto devinit_err;
542+
543     mutex_init(&dev->write_mutex);
544+ rwlock_init(&dev->bdev_mutex);
545 
546     if (!mtdname)
547         mtdname = devname;
548@@ -297,6 +391,7 @@ static struct block2mtd_dev *add_device(
549     dev->mtd.read = block2mtd_read;
550     dev->mtd.priv = dev;
551     dev->mtd.owner = THIS_MODULE;
552+ dev->mtd.refresh_device = block2mtd_refresh;
553 
554     part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
555     part->name = dev->mtd.name;
556--- a/drivers/mtd/mtdchar.c
557+++ b/drivers/mtd/mtdchar.c
558@@ -17,6 +17,7 @@
559 
560 #include <linux/mtd/mtd.h>
561 #include <linux/mtd/compatmac.h>
562+#include <linux/mtd/partitions.h>
563 
564 #include <asm/uaccess.h>
565 
566@@ -750,6 +751,13 @@ static int mtd_ioctl(struct inode *inode
567         file->f_pos = 0;
568         break;
569     }
570+#ifdef CONFIG_MTD_PARTITIONS
571+ case MTDREFRESH:
572+ {
573+ ret = refresh_mtd_partitions(mtd);
574+ break;
575+ }
576+#endif
577 
578     default:
579         ret = -ENOTTY;
580--- a/include/linux/mtd/mtd.h
581+++ b/include/linux/mtd/mtd.h
582@@ -101,6 +101,7 @@ struct mtd_oob_ops {
583     uint8_t *oobbuf;
584 };
585 
586+struct mtd_info;
587 struct mtd_info {
588     u_char type;
589     uint32_t flags;
590@@ -241,6 +242,9 @@ struct mtd_info {
591     struct device dev;
592     int usecount;
593 
594+ int (*refresh_device)(struct mtd_info *mtd);
595+ struct mtd_info *split;
596+
597     /* If the driver is something smart, like UBI, it may need to maintain
598      * its own reference counting. The below functions are only for driver.
599      * The driver may register its callbacks. These callbacks are not
600--- a/include/linux/mtd/partitions.h
601+++ b/include/linux/mtd/partitions.h
602@@ -34,6 +34,7 @@
603  * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
604  */
605 
606+struct mtd_partition;
607 struct mtd_partition {
608     char *name; /* identifier string */
609     uint64_t size; /* partition size */
610@@ -41,6 +42,7 @@ struct mtd_partition {
611     uint32_t mask_flags; /* master MTD flags to mask out for this partition */
612     struct nand_ecclayout *ecclayout; /* out of band layout for this partition (NAND only)*/
613     struct mtd_info **mtdp; /* pointer to store the MTD object */
614+ int (*refresh_partition)(struct mtd_info *);
615 };
616 
617 #define MTDPART_OFS_NXTBLK (-2)
618@@ -50,6 +52,7 @@ struct mtd_partition {
619 
620 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
621 int del_mtd_partitions(struct mtd_info *);
622+int refresh_mtd_partitions(struct mtd_info *);
623 
624 /*
625  * Functions dealing with the various ways of partitioning the space
626--- a/include/mtd/mtd-abi.h
627+++ b/include/mtd/mtd-abi.h
628@@ -95,6 +95,7 @@ struct otp_info {
629 #define ECCGETLAYOUT _IOR('M', 17, struct nand_ecclayout)
630 #define ECCGETSTATS _IOR('M', 18, struct mtd_ecc_stats)
631 #define MTDFILEMODE _IO('M', 19)
632+#define MTDREFRESH _IO('M', 50)
633 
634 /*
635  * Obsolete legacy interface. Keep it in order not to break userspace
636

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