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authorFelix Fietkau <nbd@openwrt.org>2010-06-26 20:42:58 +0000
committerFelix Fietkau <nbd@openwrt.org>2010-06-26 20:42:58 +0000
commitda1bb88a2b900f0392b731ec47c5e1bff956fd8f (patch)
tree597146471e3eeafb4ba55e802e80b896770808ff /target/linux/generic/patches-2.6.25/065-rootfs_split.patch
parent6117c04c9416b295347fb45c37e430f01df1d0d9 (diff)
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rename target/linux/generic-2.6 to generic
SVN-Revision: 21952
Diffstat (limited to 'target/linux/generic/patches-2.6.25/065-rootfs_split.patch')
-rw-r--r--target/linux/generic/patches-2.6.25/065-rootfs_split.patch951
1 files changed, 951 insertions, 0 deletions
diff --git a/target/linux/generic/patches-2.6.25/065-rootfs_split.patch b/target/linux/generic/patches-2.6.25/065-rootfs_split.patch
new file mode 100644
index 0000000000..5b882c6063
--- /dev/null
+++ b/target/linux/generic/patches-2.6.25/065-rootfs_split.patch
@@ -0,0 +1,951 @@
+--- a/drivers/mtd/Kconfig
++++ b/drivers/mtd/Kconfig
+@@ -47,6 +47,16 @@ config MTD_PARTITIONS
+ devices. Partitioning on NFTL 'devices' is a different - that's the
+ 'normal' form of partitioning used on a block device.
+
++config MTD_ROOTFS_ROOT_DEV
++ bool "Automatically set 'rootfs' partition to be root filesystem"
++ depends on MTD_PARTITIONS
++ default y
++
++config MTD_ROOTFS_SPLIT
++ bool "Automatically split 'rootfs' partition for squashfs"
++ depends on MTD_PARTITIONS
++ default y
++
+ config MTD_REDBOOT_PARTS
+ tristate "RedBoot partition table parsing"
+ depends on MTD_PARTITIONS
+--- a/drivers/mtd/mtdpart.c
++++ b/drivers/mtd/mtdpart.c
+@@ -20,6 +20,8 @@
+ #include <linux/mtd/mtd.h>
+ #include <linux/mtd/partitions.h>
+ #include <linux/mtd/compatmac.h>
++#include <linux/squashfs_fs.h>
++#include <linux/root_dev.h>
+
+ /* Our partition linked list */
+ static LIST_HEAD(mtd_partitions);
+@@ -39,7 +41,7 @@ struct mtd_part {
+ * the pointer to that structure with this macro.
+ */
+ #define PART(x) ((struct mtd_part *)(x))
+-
++#define IS_PART(mtd) (mtd->read == part_read)
+
+ /*
+ * MTD methods which simply translate the effective address and pass through
+@@ -322,6 +324,316 @@ int del_mtd_partitions(struct mtd_info *
+ return 0;
+ }
+
++static u_int32_t cur_offset = 0;
++static int add_one_partition(struct mtd_info *master, const struct mtd_partition *part,
++ int i, struct mtd_part **slp)
++{
++ struct mtd_part *slave;
++
++ /* allocate the partition structure */
++ slave = kzalloc (sizeof(*slave), GFP_KERNEL);
++ if (!slave) {
++ printk ("memory allocation error while creating partitions for \"%s\"\n",
++ master->name);
++ del_mtd_partitions(master);
++ return -ENOMEM;
++ }
++ list_add(&slave->list, &mtd_partitions);
++
++ /* set up the MTD object for this partition */
++ slave->mtd.type = master->type;
++ slave->mtd.flags = master->flags & ~part->mask_flags;
++ slave->mtd.size = part->size;
++ slave->mtd.writesize = master->writesize;
++ slave->mtd.oobsize = master->oobsize;
++ slave->mtd.oobavail = master->oobavail;
++ slave->mtd.subpage_sft = master->subpage_sft;
++
++ slave->mtd.name = part->name;
++ slave->mtd.owner = master->owner;
++
++ slave->mtd.read = part_read;
++ slave->mtd.write = part_write;
++
++ if (master->panic_write)
++ slave->mtd.panic_write = part_panic_write;
++
++ slave->mtd.refresh_device = part->refresh_partition;
++
++ if(master->point && master->unpoint){
++ slave->mtd.point = part_point;
++ slave->mtd.unpoint = part_unpoint;
++ }
++
++ if (master->read_oob)
++ slave->mtd.read_oob = part_read_oob;
++ if (master->write_oob)
++ slave->mtd.write_oob = part_write_oob;
++ if(master->read_user_prot_reg)
++ slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
++ if(master->read_fact_prot_reg)
++ slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
++ if(master->write_user_prot_reg)
++ slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
++ if(master->lock_user_prot_reg)
++ slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
++ if(master->get_user_prot_info)
++ slave->mtd.get_user_prot_info = part_get_user_prot_info;
++ if(master->get_fact_prot_info)
++ slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
++ if (master->sync)
++ slave->mtd.sync = part_sync;
++ if (!i && master->suspend && master->resume) {
++ slave->mtd.suspend = part_suspend;
++ slave->mtd.resume = part_resume;
++ }
++ if (master->writev)
++ slave->mtd.writev = part_writev;
++ if (master->lock)
++ slave->mtd.lock = part_lock;
++ if (master->unlock)
++ slave->mtd.unlock = part_unlock;
++ if (master->block_isbad)
++ slave->mtd.block_isbad = part_block_isbad;
++ if (master->block_markbad)
++ slave->mtd.block_markbad = part_block_markbad;
++ slave->mtd.erase = part_erase;
++ slave->master = master;
++ slave->offset = part->offset;
++ slave->index = i;
++
++ if (slave->offset == MTDPART_OFS_APPEND)
++ slave->offset = cur_offset;
++ if (slave->offset == MTDPART_OFS_NXTBLK) {
++ slave->offset = cur_offset;
++ if ((cur_offset % master->erasesize) != 0) {
++ /* Round up to next erasesize */
++ slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
++ printk(KERN_NOTICE "Moving partition %d: "
++ "0x%08x -> 0x%08x\n", i,
++ cur_offset, slave->offset);
++ }
++ }
++ if (slave->mtd.size == MTDPART_SIZ_FULL)
++ slave->mtd.size = master->size - slave->offset;
++ cur_offset = slave->offset + slave->mtd.size;
++
++ printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
++ slave->offset + slave->mtd.size, slave->mtd.name);
++
++ /* let's do some sanity checks */
++ if (slave->offset >= master->size) {
++ /* let's register it anyway to preserve ordering */
++ slave->offset = 0;
++ slave->mtd.size = 0;
++ printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
++ part->name);
++ }
++ if (slave->offset + slave->mtd.size > master->size) {
++ slave->mtd.size = master->size - slave->offset;
++ printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
++ part->name, master->name, slave->mtd.size);
++ }
++ if (master->numeraseregions>1) {
++ /* Deal with variable erase size stuff */
++ int i;
++ struct mtd_erase_region_info *regions = master->eraseregions;
++
++ /* Find the first erase regions which is part of this partition. */
++ for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
++ ;
++
++ for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
++ if (slave->mtd.erasesize < regions[i].erasesize) {
++ slave->mtd.erasesize = regions[i].erasesize;
++ }
++ }
++ } else {
++ /* Single erase size */
++ slave->mtd.erasesize = master->erasesize;
++ }
++
++ if ((slave->mtd.flags & MTD_WRITEABLE) &&
++ (slave->offset % slave->mtd.erasesize)) {
++ /* Doesn't start on a boundary of major erase size */
++ /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
++ slave->mtd.flags &= ~MTD_WRITEABLE;
++ printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
++ part->name);
++ }
++ if ((slave->mtd.flags & MTD_WRITEABLE) &&
++ (slave->mtd.size % slave->mtd.erasesize)) {
++ slave->mtd.flags &= ~MTD_WRITEABLE;
++ printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
++ part->name);
++ }
++
++ slave->mtd.ecclayout = master->ecclayout;
++ if (master->block_isbad) {
++ uint32_t offs = 0;
++
++ while(offs < slave->mtd.size) {
++ if (master->block_isbad(master,
++ offs + slave->offset))
++ slave->mtd.ecc_stats.badblocks++;
++ offs += slave->mtd.erasesize;
++ }
++ }
++
++ if(part->mtdp)
++ { /* store the object pointer (caller may or may not register it */
++ *part->mtdp = &slave->mtd;
++ slave->registered = 0;
++ }
++ else
++ {
++ /* register our partition */
++ add_mtd_device(&slave->mtd);
++ slave->registered = 1;
++ }
++
++ if (slp)
++ *slp = slave;
++
++ return 0;
++}
++
++#ifdef CONFIG_MTD_ROOTFS_SPLIT
++#define ROOTFS_SPLIT_NAME "rootfs_data"
++#define ROOTFS_REMOVED_NAME "<removed>"
++static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
++{
++ char buf[512];
++ struct squashfs_super_block *sb = (struct squashfs_super_block *) buf;
++ int len, ret;
++
++ ret = master->read(master, offset, sizeof(*sb), &len, buf);
++ if (ret || (len != sizeof(*sb))) {
++ printk(KERN_ALERT "split_squashfs: error occured while reading "
++ "from \"%s\"\n", master->name);
++ return -EINVAL;
++ }
++
++ if (*((u32 *) buf) != SQUASHFS_MAGIC) {
++ printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
++ master->name);
++ *split_offset = 0;
++ return 0;
++ }
++
++ if (sb->bytes_used <= 0) {
++ printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
++ master->name);
++ *split_offset = 0;
++ return 0;
++ }
++
++ len = (u32) sb->bytes_used;
++ len += (offset & 0x000fffff);
++ len += (master->erasesize - 1);
++ len &= ~(master->erasesize - 1);
++ len -= (offset & 0x000fffff);
++ *split_offset = offset + len;
++
++ return 0;
++}
++
++static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, struct mtd_partition *part,
++ int index)
++{
++ struct mtd_partition *dpart;
++ struct mtd_part *slave = NULL;
++ int split_offset = 0;
++ int ret;
++
++ ret = split_squashfs(master, part->offset, &split_offset);
++ if (ret)
++ return ret;
++
++ if (split_offset <= 0)
++ return 0;
++
++ dpart = kmalloc(sizeof(*part)+sizeof(ROOTFS_SPLIT_NAME)+1, GFP_KERNEL);
++ if (dpart == NULL) {
++ printk(KERN_INFO "split_squashfs: no memory for partition \"%s\"\n",
++ ROOTFS_SPLIT_NAME);
++ return -ENOMEM;
++ }
++
++ memcpy(dpart, part, sizeof(*part));
++ dpart->name = (unsigned char *)&dpart[1];
++ strcpy(dpart->name, ROOTFS_SPLIT_NAME);
++
++ dpart->size -= split_offset - dpart->offset;
++ dpart->offset = split_offset;
++
++ if (dpart == NULL)
++ return 1;
++
++ printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%X, len=%X \n",
++ ROOTFS_SPLIT_NAME, dpart->offset, dpart->size);
++
++ ret = add_one_partition(master, dpart, index, &slave);
++ if (ret)
++ kfree(dpart);
++ else if (slave)
++ rpart->split = &slave->mtd;
++
++ return ret;
++}
++
++static int refresh_rootfs_split(struct mtd_info *mtd)
++{
++ struct mtd_partition tpart;
++ struct mtd_part *part;
++ int index = 0;
++ int offset, size;
++ int ret;
++
++ part = PART(mtd);
++
++ /* check for the new squashfs offset first */
++ ret = split_squashfs(part->master, part->offset, &offset);
++ if (ret)
++ return ret;
++
++ if ((offset > 0) && !mtd->split) {
++ printk(KERN_INFO "%s: creating new split partition for \"%s\"\n", __func__, mtd->name);
++ /* if we don't have a rootfs split partition, create a new one */
++ tpart.name = mtd->name;
++ tpart.size = mtd->size;
++ tpart.offset = part->offset;
++
++ /* find the index of the last partition */
++ if (!list_empty(&mtd_partitions))
++ index = list_first_entry(&mtd_partitions, struct mtd_part, list)->index + 1;
++
++ return split_rootfs_data(part->master, &part->mtd, &tpart, index);
++ } else if ((offset > 0) && mtd->split) {
++ /* update the offsets of the existing partition */
++ size = mtd->size + part->offset - offset;
++
++ part = PART(mtd->split);
++ part->offset = offset;
++ part->mtd.size = size;
++ printk(KERN_INFO "%s: %s partition \"" ROOTFS_SPLIT_NAME "\", offset: 0x%06x (0x%06x)\n",
++ __func__, (!strcmp(part->mtd.name, ROOTFS_SPLIT_NAME) ? "updating" : "creating"),
++ part->offset, part->mtd.size);
++ strcpy(part->mtd.name, ROOTFS_SPLIT_NAME);
++ } else if ((offset <= 0) && mtd->split) {
++ printk(KERN_INFO "%s: removing partition \"%s\"\n", __func__, mtd->split->name);
++
++ /* mark existing partition as removed */
++ part = PART(mtd->split);
++ strcpy(part->mtd.name, ROOTFS_REMOVED_NAME);
++ part->offset = 0;
++ part->mtd.size = 0;
++ }
++
++ return 0;
++}
++#endif /* CONFIG_MTD_ROOTFS_SPLIT */
++
+ /*
+ * This function, given a master MTD object and a partition table, creates
+ * and registers slave MTD objects which are bound to the master according to
+@@ -334,171 +646,31 @@ int add_mtd_partitions(struct mtd_info *
+ int nbparts)
+ {
+ struct mtd_part *slave;
+- u_int32_t cur_offset = 0;
+- int i;
++ struct mtd_partition *part;
++ int i, j, ret = 0;
+
+ printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
+
+- for (i = 0; i < nbparts; i++) {
+-
+- /* allocate the partition structure */
+- slave = kzalloc (sizeof(*slave), GFP_KERNEL);
+- if (!slave) {
+- printk ("memory allocation error while creating partitions for \"%s\"\n",
+- master->name);
+- del_mtd_partitions(master);
+- return -ENOMEM;
+- }
+- list_add(&slave->list, &mtd_partitions);
+-
+- /* set up the MTD object for this partition */
+- slave->mtd.type = master->type;
+- slave->mtd.flags = master->flags & ~parts[i].mask_flags;
+- slave->mtd.size = parts[i].size;
+- slave->mtd.writesize = master->writesize;
+- slave->mtd.oobsize = master->oobsize;
+- slave->mtd.oobavail = master->oobavail;
+- slave->mtd.subpage_sft = master->subpage_sft;
+-
+- slave->mtd.name = parts[i].name;
+- slave->mtd.owner = master->owner;
+-
+- slave->mtd.read = part_read;
+- slave->mtd.write = part_write;
+-
+- if (master->panic_write)
+- slave->mtd.panic_write = part_panic_write;
+-
+- if(master->point && master->unpoint){
+- slave->mtd.point = part_point;
+- slave->mtd.unpoint = part_unpoint;
+- }
+-
+- if (master->read_oob)
+- slave->mtd.read_oob = part_read_oob;
+- if (master->write_oob)
+- slave->mtd.write_oob = part_write_oob;
+- if(master->read_user_prot_reg)
+- slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
+- if(master->read_fact_prot_reg)
+- slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
+- if(master->write_user_prot_reg)
+- slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
+- if(master->lock_user_prot_reg)
+- slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
+- if(master->get_user_prot_info)
+- slave->mtd.get_user_prot_info = part_get_user_prot_info;
+- if(master->get_fact_prot_info)
+- slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
+- if (master->sync)
+- slave->mtd.sync = part_sync;
+- if (!i && master->suspend && master->resume) {
+- slave->mtd.suspend = part_suspend;
+- slave->mtd.resume = part_resume;
+- }
+- if (master->writev)
+- slave->mtd.writev = part_writev;
+- if (master->lock)
+- slave->mtd.lock = part_lock;
+- if (master->unlock)
+- slave->mtd.unlock = part_unlock;
+- if (master->block_isbad)
+- slave->mtd.block_isbad = part_block_isbad;
+- if (master->block_markbad)
+- slave->mtd.block_markbad = part_block_markbad;
+- slave->mtd.erase = part_erase;
+- slave->master = master;
+- slave->offset = parts[i].offset;
+- slave->index = i;
+-
+- if (slave->offset == MTDPART_OFS_APPEND)
+- slave->offset = cur_offset;
+- if (slave->offset == MTDPART_OFS_NXTBLK) {
+- slave->offset = cur_offset;
+- if ((cur_offset % master->erasesize) != 0) {
+- /* Round up to next erasesize */
+- slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
+- printk(KERN_NOTICE "Moving partition %d: "
+- "0x%08x -> 0x%08x\n", i,
+- cur_offset, slave->offset);
+- }
+- }
+- if (slave->mtd.size == MTDPART_SIZ_FULL)
+- slave->mtd.size = master->size - slave->offset;
+- cur_offset = slave->offset + slave->mtd.size;
+-
+- printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
+- slave->offset + slave->mtd.size, slave->mtd.name);
+-
+- /* let's do some sanity checks */
+- if (slave->offset >= master->size) {
+- /* let's register it anyway to preserve ordering */
+- slave->offset = 0;
+- slave->mtd.size = 0;
+- printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
+- parts[i].name);
+- }
+- if (slave->offset + slave->mtd.size > master->size) {
+- slave->mtd.size = master->size - slave->offset;
+- printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
+- parts[i].name, master->name, slave->mtd.size);
+- }
+- if (master->numeraseregions>1) {
+- /* Deal with variable erase size stuff */
+- int i;
+- struct mtd_erase_region_info *regions = master->eraseregions;
+-
+- /* Find the first erase regions which is part of this partition. */
+- for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
+- ;
+-
+- for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
+- if (slave->mtd.erasesize < regions[i].erasesize) {
+- slave->mtd.erasesize = regions[i].erasesize;
+- }
++ for (i = 0, j = 0; i < nbparts; i++) {
++ part = (struct mtd_partition *) &parts[i];
++ ret = add_one_partition(master, part, j, &slave);
++ if (ret)
++ return ret;
++ j++;
++
++ if (strcmp(part->name, "rootfs") == 0 && slave->registered) {
++#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++ if (ROOT_DEV == 0) {
++ printk(KERN_NOTICE "mtd: partition \"rootfs\" "
++ "set to be root filesystem\n");
++ ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
+ }
+- } else {
+- /* Single erase size */
+- slave->mtd.erasesize = master->erasesize;
+- }
+-
+- if ((slave->mtd.flags & MTD_WRITEABLE) &&
+- (slave->offset % slave->mtd.erasesize)) {
+- /* Doesn't start on a boundary of major erase size */
+- /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
+- slave->mtd.flags &= ~MTD_WRITEABLE;
+- printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
+- parts[i].name);
+- }
+- if ((slave->mtd.flags & MTD_WRITEABLE) &&
+- (slave->mtd.size % slave->mtd.erasesize)) {
+- slave->mtd.flags &= ~MTD_WRITEABLE;
+- printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
+- parts[i].name);
+- }
+-
+- slave->mtd.ecclayout = master->ecclayout;
+- if (master->block_isbad) {
+- uint32_t offs = 0;
+-
+- while(offs < slave->mtd.size) {
+- if (master->block_isbad(master,
+- offs + slave->offset))
+- slave->mtd.ecc_stats.badblocks++;
+- offs += slave->mtd.erasesize;
+- }
+- }
+-
+- if(parts[i].mtdp)
+- { /* store the object pointer (caller may or may not register it */
+- *parts[i].mtdp = &slave->mtd;
+- slave->registered = 0;
+- }
+- else
+- {
+- /* register our partition */
+- add_mtd_device(&slave->mtd);
+- slave->registered = 1;
++#endif
++#ifdef CONFIG_MTD_ROOTFS_SPLIT
++ ret = split_rootfs_data(master, &slave->mtd, part, j);
++ if (ret == 0)
++ j++;
++#endif
+ }
+ }
+
+@@ -574,6 +746,32 @@ int parse_mtd_partitions(struct mtd_info
+ return ret;
+ }
+
++int refresh_mtd_partitions(struct mtd_info *mtd)
++{
++ int ret = 0;
++
++ if (IS_PART(mtd)) {
++ struct mtd_part *part;
++ struct mtd_info *master;
++
++ part = PART(mtd);
++ master = part->master;
++ if (master->refresh_device)
++ ret = master->refresh_device(master);
++ }
++
++ if (!ret && mtd->refresh_device)
++ ret = mtd->refresh_device(mtd);
++
++#ifdef CONFIG_MTD_ROOTFS_SPLIT
++ if (!ret && IS_PART(mtd) && !strcmp(mtd->name, "rootfs"))
++ refresh_rootfs_split(mtd);
++#endif
++
++ return 0;
++}
++
+ EXPORT_SYMBOL_GPL(parse_mtd_partitions);
++EXPORT_SYMBOL_GPL(refresh_mtd_partitions);
+ EXPORT_SYMBOL_GPL(register_mtd_parser);
+ EXPORT_SYMBOL_GPL(deregister_mtd_parser);
+--- a/drivers/mtd/devices/block2mtd.c
++++ b/drivers/mtd/devices/block2mtd.c
+@@ -34,6 +34,8 @@ struct block2mtd_dev {
+ struct block_device *blkdev;
+ struct mtd_info mtd;
+ struct mutex write_mutex;
++ rwlock_t bdev_mutex;
++ char devname[0];
+ };
+
+
+@@ -86,6 +88,12 @@ static int block2mtd_erase(struct mtd_in
+ size_t len = instr->len;
+ int err;
+
++ read_lock(&dev->bdev_mutex);
++ if (!dev->blkdev) {
++ err = -EINVAL;
++ goto done;
++ }
++
+ instr->state = MTD_ERASING;
+ mutex_lock(&dev->write_mutex);
+ err = _block2mtd_erase(dev, from, len);
+@@ -98,6 +106,10 @@ static int block2mtd_erase(struct mtd_in
+
+ instr->state = MTD_ERASE_DONE;
+ mtd_erase_callback(instr);
++
++done:
++ read_unlock(&dev->bdev_mutex);
++
+ return err;
+ }
+
+@@ -109,10 +121,14 @@ static int block2mtd_read(struct mtd_inf
+ struct page *page;
+ int index = from >> PAGE_SHIFT;
+ int offset = from & (PAGE_SIZE-1);
+- int cpylen;
++ int cpylen, err = 0;
++
++ read_lock(&dev->bdev_mutex);
++ if (!dev->blkdev || (from > mtd->size)) {
++ err = -EINVAL;
++ goto done;
++ }
+
+- if (from > mtd->size)
+- return -EINVAL;
+ if (from + len > mtd->size)
+ len = mtd->size - from;
+
+@@ -127,10 +143,14 @@ static int block2mtd_read(struct mtd_inf
+ len = len - cpylen;
+
+ page = page_read(dev->blkdev->bd_inode->i_mapping, index);
+- if (!page)
+- return -ENOMEM;
+- if (IS_ERR(page))
+- return PTR_ERR(page);
++ if (!page) {
++ err = -ENOMEM;
++ goto done;
++ }
++ if (IS_ERR(page)) {
++ err = PTR_ERR(page);
++ goto done;
++ }
+
+ memcpy(buf, page_address(page) + offset, cpylen);
+ page_cache_release(page);
+@@ -141,7 +161,10 @@ static int block2mtd_read(struct mtd_inf
+ offset = 0;
+ index++;
+ }
+- return 0;
++
++done:
++ read_unlock(&dev->bdev_mutex);
++ return err;
+ }
+
+
+@@ -193,12 +216,22 @@ static int block2mtd_write(struct mtd_in
+ size_t *retlen, const u_char *buf)
+ {
+ struct block2mtd_dev *dev = mtd->priv;
+- int err;
++ int err = 0;
++
++ read_lock(&dev->bdev_mutex);
++ if (!dev->blkdev) {
++ err = -EINVAL;
++ goto done;
++ }
+
+ if (!len)
+- return 0;
+- if (to >= mtd->size)
+- return -ENOSPC;
++ goto done;
++
++ if (to >= mtd->size) {
++ err = -ENOSPC;
++ goto done;
++ }
++
+ if (to + len > mtd->size)
+ len = mtd->size - to;
+
+@@ -207,6 +240,9 @@ static int block2mtd_write(struct mtd_in
+ mutex_unlock(&dev->write_mutex);
+ if (err > 0)
+ err = 0;
++
++done:
++ read_unlock(&dev->bdev_mutex);
+ return err;
+ }
+
+@@ -215,51 +251,29 @@ static int block2mtd_write(struct mtd_in
+ static void block2mtd_sync(struct mtd_info *mtd)
+ {
+ struct block2mtd_dev *dev = mtd->priv;
+- sync_blockdev(dev->blkdev);
+- return;
+-}
+-
+-
+-static void block2mtd_free_device(struct block2mtd_dev *dev)
+-{
+- if (!dev)
+- return;
+-
+- kfree(dev->mtd.name);
+
+- if (dev->blkdev) {
+- invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
+- 0, -1);
+- close_bdev_excl(dev->blkdev);
+- }
++ read_lock(&dev->bdev_mutex);
++ if (dev->blkdev)
++ sync_blockdev(dev->blkdev);
++ read_unlock(&dev->bdev_mutex);
+
+- kfree(dev);
++ return;
+ }
+
+
+-/* FIXME: ensure that mtd->size % erase_size == 0 */
+-static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
++static int _open_bdev(struct block2mtd_dev *dev)
+ {
+ struct block_device *bdev;
+- struct block2mtd_dev *dev;
+- struct mtd_partition *part;
+-
+- if (!devname)
+- return NULL;
+-
+- dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+- if (!dev)
+- return NULL;
+
+ /* Get a handle on the device */
+- bdev = open_bdev_excl(devname, O_RDWR, NULL);
++ bdev = open_bdev_excl(dev->devname, O_RDWR, NULL);
+ #ifndef MODULE
+ if (IS_ERR(bdev)) {
+
+ /* We might not have rootfs mounted at this point. Try
+ to resolve the device name by other means. */
+
+- dev_t devt = name_to_dev_t(devname);
++ dev_t devt = name_to_dev_t(dev->devname);
+ if (devt) {
+ bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
+ }
+@@ -267,17 +281,96 @@ static struct block2mtd_dev *add_device(
+ #endif
+
+ if (IS_ERR(bdev)) {
+- ERROR("error: cannot open device %s", devname);
+- goto devinit_err;
++ ERROR("error: cannot open device %s", dev->devname);
++ return 1;
+ }
+ dev->blkdev = bdev;
+
+ if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+ ERROR("attempting to use an MTD device as a block device");
+- goto devinit_err;
++ return 1;
+ }
+
++ return 0;
++}
++
++static void _close_bdev(struct block2mtd_dev *dev)
++{
++ struct block_device *bdev;
++
++ if (!dev->blkdev)
++ return;
++
++ bdev = dev->blkdev;
++ invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
++ close_bdev_excl(dev->blkdev);
++ dev->blkdev = NULL;
++}
++
++static void block2mtd_free_device(struct block2mtd_dev *dev)
++{
++ if (!dev)
++ return;
++
++ kfree(dev->mtd.name);
++ _close_bdev(dev);
++ kfree(dev);
++}
++
++
++static int block2mtd_refresh(struct mtd_info *mtd)
++{
++ struct block2mtd_dev *dev = mtd->priv;
++ struct block_device *bdev;
++ dev_t devt;
++ int err = 0;
++
++ /* no other mtd function can run at this point */
++ write_lock(&dev->bdev_mutex);
++
++ /* get the device number for the whole disk */
++ devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
++
++ /* close the old block device */
++ _close_bdev(dev);
++
++ /* open the whole disk, issue a partition rescan, then */
++ bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
++ if (!bdev || !bdev->bd_disk)
++ err = -EINVAL;
++ else {
++ err = rescan_partitions(bdev->bd_disk, bdev);
++ }
++ if (bdev)
++ close_bdev_excl(bdev);
++
++ /* try to open the partition block device again */
++ _open_bdev(dev);
++ write_unlock(&dev->bdev_mutex);
++
++ return err;
++}
++
++/* FIXME: ensure that mtd->size % erase_size == 0 */
++static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
++{
++ struct block2mtd_dev *dev;
++ struct mtd_partition *part;
++
++ if (!devname)
++ return NULL;
++
++ dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
++ if (!dev)
++ return NULL;
++
++ strcpy(dev->devname, devname);
++
++ if (_open_bdev(dev))
++ goto devinit_err;
++
+ mutex_init(&dev->write_mutex);
++ rwlock_init(&dev->bdev_mutex);
+
+ /* Setup the MTD structure */
+ /* make the name contain the block device in */
+@@ -304,6 +397,7 @@ static struct block2mtd_dev *add_device(
+ dev->mtd.read = block2mtd_read;
+ dev->mtd.priv = dev;
+ dev->mtd.owner = THIS_MODULE;
++ dev->mtd.refresh_device = block2mtd_refresh;
+
+ part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
+ part->name = dev->mtd.name;
+--- a/drivers/mtd/mtdchar.c
++++ b/drivers/mtd/mtdchar.c
+@@ -17,6 +17,7 @@
+
+ #include <linux/mtd/mtd.h>
+ #include <linux/mtd/compatmac.h>
++#include <linux/mtd/partitions.h>
+
+ #include <asm/uaccess.h>
+
+@@ -756,6 +757,13 @@ static int mtd_ioctl(struct inode *inode
+ file->f_pos = 0;
+ break;
+ }
++#ifdef CONFIG_MTD_PARTITIONS
++ case MTDREFRESH:
++ {
++ ret = refresh_mtd_partitions(mtd);
++ break;
++ }
++#endif
+
+ default:
+ ret = -ENOTTY;
+--- a/include/linux/mtd/mtd.h
++++ b/include/linux/mtd/mtd.h
+@@ -98,6 +98,7 @@ struct mtd_oob_ops {
+ uint8_t *oobbuf;
+ };
+
++struct mtd_info;
+ struct mtd_info {
+ u_char type;
+ u_int32_t flags;
+@@ -211,6 +212,9 @@ struct mtd_info {
+ struct module *owner;
+ int usecount;
+
++ int (*refresh_device)(struct mtd_info *mtd);
++ struct mtd_info *split;
++
+ /* If the driver is something smart, like UBI, it may need to maintain
+ * its own reference counting. The below functions are only for driver.
+ * The driver may register its callbacks. These callbacks are not
+--- a/include/linux/mtd/partitions.h
++++ b/include/linux/mtd/partitions.h
+@@ -36,6 +36,7 @@
+ * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
+ */
+
++struct mtd_partition;
+ struct mtd_partition {
+ char *name; /* identifier string */
+ u_int32_t size; /* partition size */
+@@ -43,6 +44,7 @@ struct mtd_partition {
+ u_int32_t mask_flags; /* master MTD flags to mask out for this partition */
+ struct nand_ecclayout *ecclayout; /* out of band layout for this partition (NAND only)*/
+ struct mtd_info **mtdp; /* pointer to store the MTD object */
++ int (*refresh_partition)(struct mtd_info *);
+ };
+
+ #define MTDPART_OFS_NXTBLK (-2)
+@@ -52,6 +54,7 @@ struct mtd_partition {
+
+ int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
+ int del_mtd_partitions(struct mtd_info *);
++int refresh_mtd_partitions(struct mtd_info *);
+
+ /*
+ * Functions dealing with the various ways of partitioning the space
+--- a/include/mtd/mtd-abi.h
++++ b/include/mtd/mtd-abi.h
+@@ -95,6 +95,7 @@ struct otp_info {
+ #define ECCGETLAYOUT _IOR('M', 17, struct nand_ecclayout)
+ #define ECCGETSTATS _IOR('M', 18, struct mtd_ecc_stats)
+ #define MTDFILEMODE _IO('M', 19)
++#define MTDREFRESH _IO('M', 23)
+
+ /*
+ * Obsolete legacy interface. Keep it in order not to break userspace