target/linux/generic/patches-3.10/400-rootfs_split.patch

   1 --- a/drivers/mtd/Kconfig
   2 +++ b/drivers/mtd/Kconfig
   3 @@ -23,6 +23,14 @@ config MTD_TESTS
   4           WARNING: some of the tests will ERASE entire MTD device which they
   5           test. Do not use these tests unless you really know what you do.
   6
   7 +config MTD_ROOTFS_ROOT_DEV
   8 +       bool "Automatically set 'rootfs' partition to be root filesystem"
   9 +       default y
  10 +
  11 +config MTD_ROOTFS_SPLIT
  12 +       bool "Automatically split 'rootfs' partition for squashfs"
  13 +       default y
  14 +
  15  config MTD_REDBOOT_PARTS
  16         tristate "RedBoot partition table parsing"
  17         ---help---
  18 --- a/drivers/mtd/mtdpart.c
  19 +++ b/drivers/mtd/mtdpart.c
  20 @@ -29,6 +29,8 @@
  21  #include <linux/kmod.h>
  22  #include <linux/mtd/mtd.h>
  23  #include <linux/mtd/partitions.h>
  24 +#include <linux/root_dev.h>
  25 +#include <linux/magic.h>
  26  #include <linux/err.h>
  27
  28  #include "mtdcore.h"
  29 @@ -50,7 +52,7 @@ struct mtd_part {
  30   * the pointer to that structure with this macro.
  31   */
  32  #define PART(x)  ((struct mtd_part *)(x))
  33 -
  34 +#define IS_PART(mtd) (mtd->_read == part_read)
  35
  36  /*
  37   * MTD methods which simply translate the effective address and pass through
  38 @@ -613,6 +615,92 @@ int mtd_del_partition(struct mtd_info *m
  39  }
  40  EXPORT_SYMBOL_GPL(mtd_del_partition);
  41
  42 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
  43 +#define ROOTFS_SPLIT_NAME "rootfs_data"
  44 +#define ROOTFS_REMOVED_NAME "<removed>"
  45 +
  46 +struct squashfs_super_block {
  47 +       __le32 s_magic;
  48 +       __le32 pad0[9];
  49 +       __le64 bytes_used;
  50 +};
  51 +
  52 +
  53 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
  54 +{
  55 +       struct squashfs_super_block sb;
  56 +       int len, ret;
  57 +
  58 +       ret = mtd_read(master, offset, sizeof(sb), &len, (void *) &sb);
  59 +       if (ret || (len != sizeof(sb))) {
  60 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
  61 +                       "from \"%s\"\n", master->name);
  62 +               return -EINVAL;
  63 +       }
  64 +
  65 +       if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
  66 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
  67 +                       master->name);
  68 +               *split_offset = 0;
  69 +               return 0;
  70 +       }
  71 +
  72 +       if (le64_to_cpu((sb.bytes_used)) <= 0) {
  73 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
  74 +                       master->name);
  75 +               *split_offset = 0;
  76 +               return 0;
  77 +       }
  78 +
  79 +       len = (u32) le64_to_cpu(sb.bytes_used);
  80 +       len += (offset & 0x000fffff);
  81 +       len +=  (master->erasesize - 1);
  82 +       len &= ~(master->erasesize - 1);
  83 +       len -= (offset & 0x000fffff);
  84 +       *split_offset = offset + len;
  85 +
  86 +       return 0;
  87 +}
  88 +
  89 +static int split_rootfs_data(struct mtd_info *master, struct mtd_info *rpart, const struct mtd_partition *part)
  90 +{
  91 +       struct mtd_partition dpart;
  92 +       struct mtd_part *slave = NULL;
  93 +       struct mtd_part *spart;
  94 +       int ret, split_offset = 0;
  95 +
  96 +       spart = PART(rpart);
  97 +       ret = split_squashfs(master, spart->offset, &split_offset);
  98 +       if (ret)
  99 +               return ret;
 100 +
 101 +       if (split_offset <= 0)
 102 +               return 0;
 103 +
 104 +       memcpy(&dpart, part, sizeof(dpart));
 105 +       dpart.name = ROOTFS_SPLIT_NAME;
 106 +
 107 +       dpart.size = rpart->size - (split_offset - spart->offset);
 108 +       dpart.offset = split_offset;
 109 +
 110 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=%llX, len=%llX \n",
 111 +               ROOTFS_SPLIT_NAME, dpart.offset, dpart.size);
 112 +
 113 +       slave = allocate_partition(master, &dpart, 0, split_offset);
 114 +       if (IS_ERR(slave))
 115 +               return PTR_ERR(slave);
 116 +       mutex_lock(&mtd_partitions_mutex);
 117 +       list_add(&slave->list, &mtd_partitions);
 118 +       mutex_unlock(&mtd_partitions_mutex);
 119 +
 120 +       add_mtd_device(&slave->mtd);
 121 +
 122 +       rpart->split = &slave->mtd;
 123 +
 124 +       return 0;
 125 +}
 126 +#endif /* CONFIG_MTD_ROOTFS_SPLIT */
 127 +
 128  /*
 129   * This function, given a master MTD object and a partition table, creates
 130   * and registers slave MTD objects which are bound to the master according to
 131 @@ -629,6 +717,9 @@ int add_mtd_partitions(struct mtd_info *
 132         struct mtd_part *slave;
 133         uint64_t cur_offset = 0;
 134         int i;
 135 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 136 +       int ret;
 137 +#endif
 138
 139         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 140
 141 @@ -643,6 +734,21 @@ int add_mtd_partitions(struct mtd_info *
 142
 143                 add_mtd_device(&slave->mtd);
 144
 145 +               if (!strcmp(parts[i].name, "rootfs")) {
 146 +#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
 147 +                       if (ROOT_DEV == 0) {
 148 +                               printk(KERN_NOTICE "mtd: partition \"rootfs\" "
 149 +                                       "set to be root filesystem\n");
 150 +                               ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, slave->mtd.index);
 151 +                       }
 152 +#endif
 153 +#ifdef CONFIG_MTD_ROOTFS_SPLIT
 154 +                       ret = split_rootfs_data(master, &slave->mtd, &parts[i]);
 155 +                       /* if (ret == 0)
 156 +                        *      j++; */
 157 +#endif
 158 +               }
 159 +
 160                 cur_offset = slave->offset + slave->mtd.size;
 161         }
 162
 163 --- a/include/linux/mtd/mtd.h
 164 +++ b/include/linux/mtd/mtd.h
 165 @@ -114,6 +114,7 @@ struct nand_ecclayout {
 166
 167  struct module; /* only needed for owner field in mtd_info */
 168
 169 +struct mtd_info;
 170  struct mtd_info {
 171         u_char type;
 172         uint32_t flags;
 173 @@ -226,6 +227,8 @@ struct mtd_info {
 174         int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
 175         int (*_suspend) (struct mtd_info *mtd);
 176         void (*_resume) (struct mtd_info *mtd);
 177 +       struct mtd_info *split;
 178 +
 179         /*
 180          * If the driver is something smart, like UBI, it may need to maintain
 181          * its own reference counting. The below functions are only for driver.