toaruos/kernel/fs/ext2_initrd.c
2011-12-14 22:15:47 -06:00

393 lines
11 KiB
C

#include <system.h>
#include <ext2.h>
#include <fs.h>
#include <logging.h>
ext2_superblock_t * initrd_superblock;
ext2_inodetable_t * initrd_root_node;
ext2_bgdescriptor_t * initrd_root_block;
ext2_inodetable_t * initrd_inode_table;
void * initrd_start;
fs_node_t * initrd_root;
fs_node_t * initrd_dev;
uint32_t initrd_node_from_file(ext2_inodetable_t *inode, ext2_dir_t *direntry, fs_node_t *fnode);
uint32_t read_initrd(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer);
uint32_t write_initrd(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer);
void open_initrd(fs_node_t *node, uint8_t read, uint8_t write);
void close_initrd(fs_node_t *node);
struct dirent *readdir_initrd(fs_node_t *node, uint32_t index);
fs_node_t *finddir_initrd(fs_node_t *node, char *name);
ext2_dir_t * ext2_get_direntry(ext2_inodetable_t * inode, uint32_t index);
ext2_inodetable_t * ext2_get_inode(uint32_t inode);
void * ext2_get_block(uint32_t block);
void * ext2_get_inode_block(ext2_inodetable_t * inode, uint32_t block);
uint32_t
read_initrd(
fs_node_t *node,
uint32_t offset,
uint32_t size,
uint8_t *buffer
) {
ext2_inodetable_t * inode = ext2_get_inode(node->inode);
uint32_t end;
if (offset + size > inode->size) {
end = inode->size;
} else {
end = offset + size;
}
uint32_t block_size = 1024 << initrd_superblock->log_block_size;
uint32_t start_block = offset / block_size;
uint32_t end_block = end / block_size;
uint32_t end_size = end % block_size;
uint32_t size_to_read = end - offset;
if (start_block == end_block) {
memcpy(buffer, (void *)((uintptr_t)ext2_get_inode_block(inode, start_block) + offset % block_size), size_to_read);
return size_to_read;
} else {
uint32_t block_offset = start_block;
uint32_t blocks_read = 0;
for (block_offset = start_block; block_offset < end_block; ++block_offset) {
if (block_offset == start_block) {
memcpy(buffer, (void *)((uintptr_t)ext2_get_inode_block(inode, block_offset) + (offset % block_size)), (block_size - (offset % block_size)));
} else {
memcpy(buffer + block_size * blocks_read - (offset % block_size), ext2_get_inode_block(inode, block_offset), block_size);
}
blocks_read++;
}
memcpy(buffer + block_size * blocks_read - (offset % block_size), ext2_get_inode_block(inode, end_block), end_size);
}
return size_to_read;
}
uint32_t
write_initrd(
fs_node_t *node,
uint32_t offset,
uint32_t size,
uint8_t *buffer
) {
/*
* Not implemented
*/
return 0;
}
void
open_initrd(
fs_node_t *node,
uint8_t read,
uint8_t write
) {
// woosh
}
void
close_initrd(
fs_node_t *node
) {
free(node);
/*
* Nothing to do here
*/
}
struct dirent *
readdir_initrd(
fs_node_t *node,
uint32_t index
) {
ext2_inodetable_t * inode = ext2_get_inode(node->inode);
assert(inode->mode & EXT2_S_IFDIR);
ext2_dir_t * direntry = ext2_get_direntry(inode, index);
if (!direntry) {
return NULL;
}
struct dirent * dirent = malloc(sizeof(struct dirent));
memcpy(&dirent->name, &direntry->name, direntry->name_len);
dirent->name[direntry->name_len] = '\0';
dirent->ino = direntry->inode;
return dirent;
}
/*
* find the child entry named `name` within the directory
* node `node`. The VFS has already checked that `node` is
* a valid directory, but we'll do that again just to be safe,
* and just in case someone didn't use the VFS layer to call us.
* Basically, run through the directory entries until we find
* the one requested and build an fs_node_t for it. The requester
* will have to free it when they are done with it.
*/
fs_node_t *
finddir_initrd(
fs_node_t *node,
char *name
) {
/*
* Find the actual inode in the ramdisk image for the requested file
*/
ext2_inodetable_t * inode = ext2_get_inode(node->inode);
assert(inode->mode & EXT2_S_IFDIR);
void * block;
ext2_dir_t * direntry = NULL;
block = (void *)ext2_get_inode_block(inode, 0);
uint32_t dir_offset;
dir_offset = 0;
/*
* Look through the requested entries until we find what we're looking for
*/
while (dir_offset < inode->size) {
ext2_dir_t * d_ent = (ext2_dir_t *)((uintptr_t)block + dir_offset);
#if 0
if (strlen(name) != d_ent->name_len) {
dir_offset += d_ent->rec_len;
continue;
}
#endif
char * dname = malloc(sizeof(char) * (d_ent->name_len + 1));
memcpy(dname, &d_ent->name, d_ent->name_len);
dname[d_ent->name_len] = '\0';
if (!strcmp(dname, name)) {
free(dname);
direntry = d_ent;
break;
}
free(dname);
dir_offset += d_ent->rec_len;
}
if (!direntry) {
/*
* We could not find the requested entry in this directory.
*/
return NULL;
}
fs_node_t * outnode = malloc(sizeof(fs_node_t));
initrd_node_from_file(ext2_get_inode(direntry->inode), direntry, outnode);
return outnode;
}
uint32_t
initrd_node_from_file(
ext2_inodetable_t * inode,
ext2_dir_t * direntry,
fs_node_t * fnode
) {
if (!fnode) {
/* You didn't give me a node to write into, go *** yourself */
return 0;
}
/* Information from the direntry */
fnode->inode = direntry->inode;
memcpy(&fnode->name, &direntry->name, direntry->name_len);
fnode->name[direntry->name_len] = '\0';
/* Information from the inode */
fnode->uid = inode->uid;
fnode->gid = inode->gid;
fnode->length = inode->size;
fnode->mask = inode->mode & 0xFFF;
/* File Flags */
fnode->flags = 0;
if ((inode->mode & EXT2_S_IFREG) == EXT2_S_IFREG) {
fnode->flags |= FS_FILE;
}
if ((inode->mode & EXT2_S_IFDIR) == EXT2_S_IFDIR) {
fnode->flags |= FS_DIRECTORY;
}
if ((inode->mode & EXT2_S_IFBLK) == EXT2_S_IFBLK) {
fnode->flags |= FS_BLOCKDEVICE;
}
if ((inode->mode & EXT2_S_IFCHR) == EXT2_S_IFCHR) {
fnode->flags |= FS_CHARDEVICE;
}
if ((inode->mode & EXT2_S_IFIFO) == EXT2_S_IFIFO) {
fnode->flags |= FS_PIPE;
}
if ((inode->mode & EXT2_S_IFLNK) == EXT2_S_IFLNK) {
fnode->flags |= FS_SYMLINK;
}
fnode->read = read_initrd;
fnode->write = write_initrd;
fnode->open = open_initrd;
fnode->close = close_initrd;
fnode->readdir = readdir_initrd;
fnode->finddir = finddir_initrd;
return 1;
}
uint32_t
initrd_node_root(
ext2_inodetable_t * inode,
fs_node_t * fnode
) {
if (!fnode) {
return 0;
}
/* Information from the direntry */
fnode->inode = 2;
fnode->name[0] = '/';
fnode->name[1] = '\0';
/* Information from the inode */
fnode->uid = inode->uid;
fnode->gid = inode->gid;
fnode->length = inode->size;
fnode->mask = inode->mode & 0xFFF;
/* File Flags */
fnode->flags = 0;
if ((inode->mode & EXT2_S_IFREG) == EXT2_S_IFREG) {
fnode->flags |= FS_FILE;
}
if ((inode->mode & EXT2_S_IFDIR) == EXT2_S_IFDIR) {
fnode->flags |= FS_DIRECTORY;
}
if ((inode->mode & EXT2_S_IFBLK) == EXT2_S_IFBLK) {
fnode->flags |= FS_BLOCKDEVICE;
}
if ((inode->mode & EXT2_S_IFCHR) == EXT2_S_IFCHR) {
fnode->flags |= FS_CHARDEVICE;
}
if ((inode->mode & EXT2_S_IFIFO) == EXT2_S_IFIFO) {
fnode->flags |= FS_PIPE;
}
if ((inode->mode & EXT2_S_IFLNK) == EXT2_S_IFLNK) {
fnode->flags |= FS_SYMLINK;
}
fnode->read = read_initrd;
fnode->write = write_initrd;
fnode->open = open_initrd;
fnode->close = close_initrd;
fnode->readdir = readdir_initrd;
fnode->finddir = finddir_initrd;
return 1;
}
uint32_t
initrd_node_from_dirent(
ext2_inodetable_t * inode,
struct dirent * direntry,
fs_node_t * fnode
) {
if (!fnode) {
/* You didn't give me a node to write into, go *** yourself */
return 0;
}
/* Information from the direntry */
fnode->inode = direntry->ino;
memcpy(&fnode->name, &direntry->name, strlen(direntry->name));
fnode->name[strlen(direntry->name)] = '\0';
/* Information from the inode */
fnode->uid = inode->uid;
fnode->gid = inode->gid;
fnode->length = inode->size;
fnode->mask = inode->mode & 0xFFF;
/* File Flags */
fnode->flags = 0;
if ((inode->mode & EXT2_S_IFREG) == EXT2_S_IFREG) {
fnode->flags |= FS_FILE;
}
if ((inode->mode & EXT2_S_IFDIR) == EXT2_S_IFDIR) {
fnode->flags |= FS_DIRECTORY;
}
if ((inode->mode & EXT2_S_IFBLK) == EXT2_S_IFBLK) {
fnode->flags |= FS_BLOCKDEVICE;
}
if ((inode->mode & EXT2_S_IFCHR) == EXT2_S_IFCHR) {
fnode->flags |= FS_CHARDEVICE;
}
if ((inode->mode & EXT2_S_IFIFO) == EXT2_S_IFIFO) {
fnode->flags |= FS_PIPE;
}
if ((inode->mode & EXT2_S_IFLNK) == EXT2_S_IFLNK) {
fnode->flags |= FS_SYMLINK;
}
fnode->read = read_initrd;
fnode->write = write_initrd;
fnode->open = open_initrd;
fnode->close = close_initrd;
fnode->readdir = readdir_initrd;
fnode->finddir = finddir_initrd;
return 1;
}
ext2_inodetable_t *
ext2_get_inode(
uint32_t inode
) {
return (ext2_inodetable_t *)((uintptr_t)initrd_inode_table + initrd_superblock->inode_size * (inode - 1));
}
void *
ext2_get_inode_block(
ext2_inodetable_t * inode,
uint32_t block
) {
if (block < 12) {
return ext2_get_block(inode->block[block]);
} else if (block < 12 + (1024 << initrd_superblock->log_block_size) / sizeof(uint32_t)) {
return ext2_get_block(*(uint32_t*)((uintptr_t)ext2_get_block(inode->block[12]) + (block - 12) * sizeof(uint32_t)));
} else if (block < 12 + 256 + 256 * 256) {
uint32_t a = block - 12;
uint32_t b = a - 256;
uint32_t c = b / 256;
uint32_t d = b - c * 256;
void * c_block = ext2_get_block(*(uint32_t *)((uintptr_t)ext2_get_block(inode->block[13]) + (c) * sizeof(uint32_t)));
return ext2_get_block(*(uint32_t *)((uintptr_t)c_block + (d) * sizeof(uint32_t)));
}
return NULL;
}
void *
ext2_get_block(
uint32_t block
) {
return (void *)((uintptr_t)initrd_start + (1024 << initrd_superblock->log_block_size) * block);
}
ext2_dir_t *
ext2_get_direntry(
ext2_inodetable_t * inode,
uint32_t index
) {
void * block;
block = (void *)ext2_get_inode_block(inode,0);
uint32_t dir_offset;
dir_offset = 0;
uint32_t dir_index;
dir_index = 0;
while (dir_offset < inode->size) {
ext2_dir_t * d_ent = (ext2_dir_t *)((uintptr_t)block + dir_offset);
if (dir_index == index) {
return d_ent;
}
dir_offset += d_ent->rec_len;
dir_index++;
}
return NULL;
}
void
initrd_mount(
uint32_t mem_head,
uint32_t mem_top
) {
initrd_start = (void *)mem_head;
initrd_superblock = (ext2_superblock_t *)((uintptr_t)initrd_start + 1024);
assert(initrd_superblock->magic == EXT2_SUPER_MAGIC);
if (initrd_superblock->inode_size == 0) {
/**
* Broken EXT2 instances may not give us a proper size for this.
* We will assume it is 128.
*/
initrd_superblock->inode_size = 128;
}
initrd_root_block = (ext2_bgdescriptor_t *)((uintptr_t)initrd_start + 1024 + 1024);
initrd_inode_table = (ext2_inodetable_t *)((uintptr_t)initrd_start + (1024 << initrd_superblock->log_block_size) * initrd_root_block->inode_table);
ext2_inodetable_t * root_inode = ext2_get_inode(2);
initrd_root = (fs_node_t *)malloc(sizeof(fs_node_t));
assert(initrd_node_root(root_inode, initrd_root));
fs_root = initrd_root;
LOG(INFO, "Mounted EXT2 ramdisk at 0x%x-0x%x, root VFS node is 0x%x", mem_head, mem_top, initrd_root);
}