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Support fragments and chunks for data

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2010-12-09 17:06:49 +01:00
parent 7ed6c3e85f
commit 948ebd7e91
1 changed files with 64 additions and 27 deletions
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91
grub-core/fs/squash4.c
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@ -28,16 +28,16 @@
#include <grub/deflate.h>
/*
object format Pointed by
superblock RAW Fixed offset (0)
data RAW ? Fixed offset (60)
inode table Chunk superblock
dir table Chunk superblock
unk3 Chunk unk1
unk1 RAW, Chunk superblock
unk2 RAW superblock
UID/GID Chunk exttblptr
exttblptr RAW superblock
object format Pointed by
superblock RAW Fixed offset (0)
data RAW ? Fixed offset (60)
inode table Chunk superblock
dir table Chunk superblock
fragment table Chunk unk1
unk1 RAW, Chunk superblock
unk2 RAW superblock
UID/GID Chunk exttblptr
exttblptr RAW superblock
UID/GID table is the array ot uint32_t
unk1 contains pointer to unk3 followed by some chunk.
@ -73,8 +73,8 @@ struct grub_squash_inode
grub_uint16_t dummy1[3];
grub_uint32_t mtime;
grub_uint16_t dummy2[2];
grub_uint16_t chunk;
grub_uint16_t dummy3[3];
grub_uint32_t chunk;
grub_uint32_t fragment;
grub_uint32_t offset;
grub_uint32_t size;
} __attribute__ ((packed));
@ -105,10 +105,30 @@ struct grub_squash_dirent
char name[0];
};
struct grub_squash_frag_desc
{
grub_uint64_t offset;
grub_uint64_t dummy;
};
#define SQUASH_CHUNK_SIZE 0x2000
#define SQUASH_CHUNK_FLAGS 0x8000
#define SQUASH_CHUNK_UNCOMPRESSED 0x8000
struct grub_squash_data
{
grub_disk_t disk;
struct grub_squash_super sb;
struct grub_squash_inode ino;
grub_uint64_t fragments;
};
struct grub_fshelp_node
{
struct grub_squash_data *data;
struct grub_squash_inode ino;
};
static grub_err_t
read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
grub_uint64_t chunk, unsigned nchunk, grub_off_t offset)
@ -161,25 +181,13 @@ read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
return GRUB_ERR_NONE;
}
struct grub_squash_data
{
grub_disk_t disk;
struct grub_squash_super sb;
struct grub_squash_inode ino;
};
struct grub_fshelp_node
{
struct grub_squash_data *data;
struct grub_squash_inode ino;
};
static struct grub_squash_data *
squash_mount (grub_disk_t disk)
{
struct grub_squash_super sb;
grub_err_t err;
struct grub_squash_data *data;
grub_uint64_t frag;
err = grub_disk_read (disk, 0, 0, sizeof (sb), &sb);
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
@ -191,11 +199,22 @@ squash_mount (grub_disk_t disk)
grub_error (GRUB_ERR_BAD_FS, "not squash4");
return NULL;
}
err = grub_disk_read (disk, grub_le_to_cpu32 (sb.unk1offset)
>> GRUB_DISK_SECTOR_BITS,
grub_le_to_cpu32 (sb.unk1offset)
& (GRUB_DISK_SECTOR_SIZE - 1), sizeof (frag), &frag);
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
grub_error (GRUB_ERR_BAD_FS, "not a squash4");
if (err)
return NULL;
data = grub_malloc (sizeof (*data));
if (!data)
return NULL;
data->sb = sb;
data->disk = disk;
data->fragments = frag;
return data;
}
@ -356,6 +375,7 @@ grub_squash_open (struct grub_file *file, const char *name)
file->data = data;
data->ino = fdiro->ino;
file->size = grub_le_to_cpu32 (fdiro->ino.size);
return GRUB_ERR_NONE;
}
@ -366,8 +386,25 @@ grub_squash_read (grub_file_t file, char *buf, grub_size_t len)
grub_uint64_t a;
struct grub_squash_data *data = file->data;
a = sizeof (struct grub_squash_super) + grub_le_to_cpu32 (data->ino.offset)
+ file->offset;
a = grub_le_to_cpu32 (data->ino.offset) + file->offset;
if (grub_le_to_cpu16 (data->ino.fragment) == 0xffff)
{
if (grub_le_to_cpu32 (data->ino.chunk))
a += grub_le_to_cpu32 (data->ino.chunk);
else
a += sizeof (struct grub_squash_super);
}
else
{
struct grub_squash_frag_desc frag;
err = read_chunk (file->device->disk, &frag, sizeof (frag),
data->fragments, 0, sizeof (frag)
* grub_le_to_cpu16 (data->ino.fragment));
if (err)
return -1;
a += grub_le_to_cpu64 (frag.offset);
a += grub_le_to_cpu32 (data->ino.chunk);
}
err = grub_disk_read (file->device->disk, a >> GRUB_DISK_SECTOR_BITS,
a & (GRUB_DISK_SECTOR_SIZE - 1), len, buf);