/**
* Allocate memory for a block in an inode whose inode number is 'no'.
*/
void ext2_disk_inode_alloc_block(ext2_inodetable_t *inode, uint32_t no, uint32_t block) {
uint32_t block_no = 0, block_offset = 0, group = 0;
char *bg_buffer = malloc(BLOCKSIZE);
for (uint32_t i = 0; i < BGDS; ++i) {
if (BGD[i].free_blocks_count > 0) {
ext2_disk_read_block(BGD[i].block_bitmap, (uint8_t *)bg_buffer);
while (BLOCKBIT(block_offset))
++block_offset;
block_no = block_offset + SB->blocks_per_group * i + 1;
group = i;
break;
}
}
if (!block_no) {
kprintf("[kernel/ext2] No available blocks!\n");
free(bg_buffer);
return;
}
// Found a block (block_no), we need to mark it as in-use
uint8_t b = BLOCKBYTE(block_offset);
b |= SETBIT(block_offset);
BLOCKBYTE(block_offset) = b;
ext2_disk_write_block(BGD[group].block_bitmap, (uint8_t *)bg_buffer);
free(bg_buffer);
ext2_set_real_block(inode, block, block_no);
// Now update available blocks count
BGD[group].free_blocks_count -= 1;
ext2_disk_write_block(2, (uint8_t *)BGD);
inode->blocks++;
ext2_disk_write_inode(inode, no);
}
uint32_t write_ext2_disk(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer) {
ext2_inodetable_t *inode = ext2_disk_inode(node->inode);
uint32_t end = offset + size;
uint32_t start_block = offset / BLOCKSIZE;
uint32_t end_block = end / BLOCKSIZE;
uint32_t end_size = end - end_block * BLOCKSIZE;
uint32_t size_to_write = end - offset;
kprintf("[kernel/ext2] Write at node 0x%x, offset %d, size %d, buffer=0x%x\n", node, offset, size, buffer);
if (end_size == 0) {
end_block--;
}
// need to update if size has increased.
if (inode->size < end) {
inode->size = end;
ext2_disk_write_inode(inode, node->inode);
}
if (start_block == end_block) {
void *buf = malloc(BLOCKSIZE);
ext2_disk_inode_read_block(inode, node->inode, start_block, buf);
memcpy((uint8_t *)((uintptr_t)buf + (offset % BLOCKSIZE)), buffer, size_to_write);
kprintf("[kernel/ext2] Single-block write.\n");
ext2_disk_inode_write_block(inode, node->inode, start_block, buf);
free(buf);
free(inode);
return size_to_write;
} else {
uint32_t block_offset;
uint32_t blocks_read = 0;
for (block_offset = start_block; block_offset < end_block; block_offset++, blocks_read++) {
if (block_offset == start_block) {
void *buf = malloc(BLOCKSIZE);
ext2_disk_inode_read_block(inode, node->inode, block_offset, buf);
memcpy((uint8_t *)((uint32_t)buf + (offset % BLOCKSIZE)), buffer, BLOCKSIZE - (offset % BLOCKSIZE));
kprintf("[kernel/ext2] Writing block [loop...]...\n");
ext2_disk_inode_write_block(inode, node->inode, start_block, buf);
free(buf);
} else {
kprintf("[kernel/ext2] Writing block [buffer...?]...\n");
ext2_disk_inode_write_block(inode, node->inode, block_offset,
buffer + BLOCKSIZE * blocks_read - (block_offset % BLOCKSIZE));
}
}
void *buf = malloc(BLOCKSIZE);
ext2_disk_inode_read_block(inode, node->inode, end_block, buf);
memcpy(buf, buffer + BLOCKSIZE * blocks_read - (block_offset % BLOCKSIZE), end_size);
kprintf("[kernel/ext2] Writing block [tail]...\n");
ext2_disk_inode_write_block(inode, node->inode, end_block, buf);
free(buf);
}
free(inode);
return size_to_write;
}
/**
* Insert an entry named 'name' with type 'type' into a directory 'p_node'
* at the end.
* This function assumes that parent directory 'p_node' does not contain
* any entry with same name as 'name'. Caller should ensure this.
*/
void insertdir_ext2_disk(ext2_inodetable_t *p_node, uint32_t no, uint32_t inode, char *name, uint8_t type) {
/* XXX HACK This needs to be seriously fixed up. */
kprintf("[kernel/ext2] Request to insert new directory entry at 0x%x#%d->%d '%s' type %d\n", p_node, no, inode, name, type);
assert(p_node->mode & EXT2_S_IFDIR);
void *block = malloc(BLOCKSIZE);
uint32_t block_nr = 0;
ext2_disk_inode_read_block(p_node, no, block_nr, block);
uint32_t dir_offset = 0;
uint32_t total_offset = 0;
// first, iterate pass the last entry in the parent directory.
while (total_offset < p_node->size) {
ext2_dir_t *d_ent = (ext2_dir_t *)((uintptr_t)block + dir_offset);
if (d_ent->rec_len + total_offset == p_node->size) {
d_ent->rec_len = d_ent->name_len + sizeof(ext2_dir_t);
while (d_ent->rec_len % 4 > 0) {
d_ent->rec_len++;
}
dir_offset += d_ent->rec_len;
total_offset += d_ent->rec_len;
break;
}
dir_offset += d_ent->rec_len;
total_offset += d_ent->rec_len;
// move on to the next block of this directory if needed.
if (dir_offset >= BLOCKSIZE) {
block_nr++;
dir_offset -= BLOCKSIZE;
ext2_disk_inode_read_block(p_node, no, block_nr, block);
kprintf("[kernel/ext2] Advancing to next block...\n");
}
}
kprintf("[kernel/ext2] Total Offset = %d; block = %d; offset within block = %d\n", total_offset, block_nr, dir_offset);
// Put the new directory entry at 'dir_offset' in block 'block_nr'.
uint32_t size = p_node->size - total_offset;
if (dir_offset + size > BLOCKSIZE) {
kprintf("\033[1;31m[kernel/ext2] Just a warning: You probably just f****d everything.\033[0m\n");
}
ext2_dir_t *new_entry = malloc(size);
// Initialize the new entry.
new_entry->inode = inode;
new_entry->rec_len = size;
new_entry->name_len = (uint8_t)strlen(name);
new_entry->file_type = type;
memcpy(&new_entry->name, name, strlen(name));
// Write back to block.
memcpy(((uint8_t *)block) + dir_offset, new_entry, size);
memset(((uint8_t *)block) + dir_offset + new_entry->rec_len, 0x00, 4);
ext2_disk_inode_write_block(p_node, no, block_nr, block);
// Update parent node size
//p_node->size += size;
ext2_disk_write_inode(p_node, no);
free(block);
}
/**
* Allocate a new inode with parent as the parent directory node and name as the filename
* within that parent directory. Returns a pointer to a memory-copy of the node which
* the client can (and should) free.
* 'ftype' is file type, used when adding the entry to the parent dir. 1 for regular file,
* 2 for directory, etc... 'no' is the inode number of 'parent'.
* Upon return, the inode number of the newly allocated inode will be stored in 'inode_no'.
*
* This function assumes that parent directory 'parent' does not contain any entry with
* same name as 'name'. Caller shuold ensure this.
* Note that inode just created using this function has size of 0, which means no data
* blocks have been allocated to the inode.
*/
ext2_inodetable_t *ext2_disk_alloc_inode
(
ext2_inodetable_t *parent,
uint32_t no,
char *name,
uint16_t mode,
uint32_t *inode_no
) {
if ((parent->mode & EXT2_S_IFDIR) == 0 || name == NULL) {
kprintf("[kernel/ext2] No name or bad parent.\n");
return NULL;
}
ext2_inodetable_t *inode;
uint32_t node_no = 0, node_offset = 0, group = 0;
char *bg_buffer = malloc(BLOCKSIZE);
/* Locate a block with an available inode. Will probably be the first block group. */
for (uint32_t i = 0; i < BGDS; ++i) {
if (BGD[i].free_inodes_count > 0) {
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("Group %d has %d free inodes!\n", i, BGD[i].free_inodes_count);
#endif
ext2_disk_read_block(BGD[i].inode_bitmap, (uint8_t *)bg_buffer);
while (BLOCKBIT(node_offset))
++node_offset;
node_no = node_offset + ext2_disk_inodes_per_group * i + 1;
group = i;
break;
}
}
if (!node_no) {
kprintf("[kernel/ext2] Failure: No free inodes in block descriptors!\n");
free(bg_buffer);
return NULL;
}
/* Alright, we found an inode (node_no), we need to mark it as in-use... */
uint8_t b = BLOCKBYTE(node_offset);
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("Located an inode at #%d (%d), the byte for this block is currently set to %x\n", node_no, node_offset, (uint32_t)b);
#endif
b |= SETBIT(node_offset);
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("We would want to set it to %x\n", (uint32_t)b);
kprintf("Setting it in our temporary buffer...\n");
#endif
BLOCKBYTE(node_offset) = b;
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("\nWriting back out.\n");
#endif
ext2_disk_write_block(BGD[group].inode_bitmap, (uint8_t *)bg_buffer);
free(bg_buffer);
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("Okay, now we need to update the available inodes count...\n");
kprintf("it is %d, it should be %d\n", BGD[group].free_inodes_count, BGD[group].free_inodes_count - 1);
kprintf("\n");
kprintf("%d\n", BGD[group].free_inodes_count);
#endif
BGD[group].free_inodes_count -= 1;
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("%d\n", BGD[group].free_inodes_count);
kprintf("\nOkay, writing the block descriptors back to disk.\n");
#endif
ext2_disk_write_block(2, (uint8_t *)BGD);
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
kprintf("Alright, we have an inode (%d), time to write it out to disk and make the file in the directory.\n", node_no);
#endif
// Get the inode struct from the disk and init it
inode = ext2_disk_inode(node_no);
inode->size = 0;
inode->blocks = 0;
inode->mode = mode;
ext2_disk_write_inode(inode, node_no);
*inode_no = node_no;
// Create an entry in the parent directory
uint8_t ftype = mode_to_filetype(mode);
kprintf("[kernel/ext2] Allocated inode, inserting directory entry [%d]...\n", node_no);
insertdir_ext2_disk(parent, no, node_no, name, ftype);
return inode;
}
/**
* Insert an entry named 'name' with type 'type' into a directory 'p_node'
* at the end.
* This function assumes that parent directory 'p_node' does not contain
* any entry with same name as 'name'. Caller should ensure this.
*/
void insertdir_ext2_disk(ext2_inodetable_t *p_node, uint32_t no, uint32_t inode, char *name, uint8_t type) {
/* XXX HACK This needs to be seriously fixed up. */
debug_print(NOTICE, "Request to insert new directory entry at 0x%x#%d->%d '%s' type %d", p_node, no, inode, name, type);
assert(p_node->mode & EXT2_S_IFDIR);
void *block = malloc(BLOCKSIZE);
uint32_t block_nr = 0;
ext2_disk_inode_read_block(p_node, no, block_nr, block);
uint32_t dir_offset = 0;
uint32_t total_offset = 0;
// first, iterate pass the last entry in the parent directory.
while (total_offset < p_node->size) {
ext2_dir_t *d_ent = (ext2_dir_t *)((uintptr_t)block + dir_offset);
if (d_ent->rec_len + total_offset == p_node->size) {
d_ent->rec_len = d_ent->name_len + sizeof(ext2_dir_t);
while (d_ent->rec_len % 4 > 0) {
d_ent->rec_len++;
}
dir_offset += d_ent->rec_len;
total_offset += d_ent->rec_len;
break;
}
dir_offset += d_ent->rec_len;
total_offset += d_ent->rec_len;
// move on to the next block of this directory if needed.
if (dir_offset >= BLOCKSIZE) {
block_nr++;
dir_offset -= BLOCKSIZE;
ext2_disk_inode_read_block(p_node, no, block_nr, block);
debug_print(NOTICE, "Advancing to next block...");
}
}
debug_print(NOTICE, "total offset = %d; block = %d; offset within block = %d", total_offset, block_nr, dir_offset);
// Put the new directory entry at 'dir_offset' in block 'block_nr'.
uint32_t size = p_node->size - total_offset;
if (dir_offset + size > BLOCKSIZE) {
debug_print(WARNING, "Directory entry is beyond first block of directory. This might be bad.");
}
ext2_dir_t *new_entry = malloc(size);
// Initialize the new entry.
new_entry->inode = inode;
new_entry->rec_len = size;
new_entry->name_len = (uint8_t)strlen(name);
new_entry->file_type = type;
memcpy(&new_entry->name, name, strlen(name));
// Write back to block.
memcpy(((uint8_t *)block) + dir_offset, new_entry, size);
memset(((uint8_t *)block) + dir_offset + new_entry->rec_len, 0x00, 4);
ext2_disk_inode_write_block(p_node, no, block_nr, block);
free(new_entry);
// Update parent node size
//p_node->size += size;
ext2_disk_write_inode(p_node, no);
free(block);
}