toaruos/kernel/fs/ext2_disk.c
2011-12-14 22:15:47 -06:00

513 lines
16 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
*/
#include <system.h>
#include <ext2.h>
#include <fs.h>
#include <logging.h>
#define EXT2_DEBUG_BLOCK_DESCRIPTORS 0
#define BLOCKSIZE 1024
#define SECTORSIZE 512
#define CACHEENTRIES 10240
#define DISK_PORT 0x1F0
typedef struct {
uint32_t block_no;
uint32_t last_use;
uint8_t block[BLOCKSIZE];
} ext2_disk_cache_entry_t;
ext2_disk_cache_entry_t *ext2_disk_cache = NULL;
ext2_superblock_t * ext2_disk_superblock = NULL;
ext2_bgdescriptor_t * ext2_disk_root_block = NULL;
fs_node_t * ext2_root_fsnode = NULL;
uint32_t ext2_disk_node_from_file(ext2_inodetable_t * inode, ext2_dir_t * direntry, fs_node_t * fnode);
uint32_t ext2_disk_inodes_per_group = 0;
uint32_t ext2_disk_bg_descriptors = 0;
#define BGDS ext2_disk_bg_descriptors
#define SB ext2_disk_superblock
#define BGD ext2_disk_root_block
#define RN ext2_root_fsnode
#define DC ext2_disk_cache
#define BLOCKBIT(n) (bg_buffer[((n) / 8)] & (1 << (((n) % 8))))
#define BLOCKBYTE(n) (bg_buffer[((n) / 8)])
#define SETBIT(n) (1 << (((n) % 8)))
static uint32_t btos(uint32_t block) {
return block * (BLOCKSIZE / SECTORSIZE);
}
static uint8_t volatile lock;
void ext2_disk_read_block(uint32_t block_no, uint8_t * buf) {
if (!block_no) return;
spin_lock(&lock);
int oldest = -1;
uint32_t oldest_age = UINT32_MAX;
for (uint32_t i = 0; i < CACHEENTRIES; ++i) {
if (DC[i].block_no == block_no) {
DC[i].last_use = now();
memcpy(buf, &DC[i].block, BLOCKSIZE);
spin_unlock(&lock);
return;
}
if (DC[i].last_use < oldest_age) {
oldest = i;
oldest_age = DC[i].last_use;
}
}
ide_read_sector(DISK_PORT, 0, btos(block_no) + 0, (uint8_t *)((uint32_t)&(DC[oldest].block) + 0));
ide_read_sector(DISK_PORT, 0, btos(block_no) + 1, (uint8_t *)((uint32_t)&(DC[oldest].block) + SECTORSIZE));
memcpy(buf, &DC[oldest].block, BLOCKSIZE);
DC[oldest].block_no = block_no;
DC[oldest].last_use = now();
spin_unlock(&lock);
}
void ext2_disk_write_block(uint32_t block_no, uint8_t * buf) {
if (!block_no) return;
spin_lock(&lock);
ide_write_sector(DISK_PORT, 0, btos(block_no) + 0, (uint8_t *)((uint32_t)buf + 0));
timer_wait(10);
ide_write_sector(DISK_PORT, 0, btos(block_no) + 1, (uint8_t *)((uint32_t)buf + SECTORSIZE));
timer_wait(10);
int oldest = -1;
uint32_t oldest_age = UINT32_MAX;
for (uint32_t i = 0; i < CACHEENTRIES; ++i) {
if (DC[i].block_no == block_no) {
DC[i].last_use = now();
memcpy(&DC[i].block, buf, BLOCKSIZE);
spin_unlock(&lock);
return;
}
if (DC[i].last_use < oldest_age) {
oldest = i;
oldest_age = DC[i].last_use;
}
}
memcpy(&DC[oldest].block, buf, BLOCKSIZE);
DC[oldest].block_no = block_no;
DC[oldest].last_use = now();
spin_unlock(&lock);
}
uint32_t ext2_disk_inode_block(ext2_inodetable_t * inode, uint32_t block, uint8_t * buf) {
if (block < 12) {
ext2_disk_read_block(inode->block[block], buf);
return inode->block[block];
} else if (block < 12 + (BLOCKSIZE << SB->log_block_size) / sizeof(uint32_t)) {
uint8_t * tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[12], tmp);
uint32_t nblock = ((uint32_t *)tmp)[block - 12];
free(tmp);
ext2_disk_read_block(nblock, buf);
return nblock;
} 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;
uint8_t * tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[13], tmp);
uint32_t nblock = ((uint32_t *)tmp)[c];
ext2_disk_read_block(nblock, tmp);
nblock = ((uint32_t *)tmp)[d];
free(tmp);
ext2_disk_read_block(nblock, buf);
return nblock;
}
HALT_AND_CATCH_FIRE("Attempted to read a file block that was too high :(", NULL);
return 0;
}
ext2_inodetable_t * ext2_disk_alloc_inode(ext2_inodetable_t * parent, char * name) {
/* 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. */
ext2_inodetable_t * inode = (ext2_inodetable_t * )malloc(BLOCKSIZE);
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) {
kprintf("Group %d has %d free inodes!\n", i, BGD[i].free_inodes_count);
ext2_disk_read_block(BGD[i].inode_bitmap, (uint8_t *)bg_buffer);
node_offset = 0;
while (BLOCKBIT(node_offset)) ++node_offset;
node_no = node_offset + ext2_disk_inodes_per_group * i + 1;
group = i;
break;
}
}
if (!node_no) {
free(inode);
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);
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);
b |= SETBIT(node_offset);
kprintf("We would want to set it to %x\n", (uint32_t)b);
kprintf("Setting it in our temporary buffer...\n");
BLOCKBYTE(node_offset) = b;
kprintf("\nWriting back out.\n");
ext2_disk_write_block(BGD[group].inode_bitmap, (uint8_t * )bg_buffer);
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);
BGD[group].free_inodes_count -= 1;
kprintf("%d\n", BGD[group].free_inodes_count);
kprintf("\nOkay, writing the block descriptors back to disk.\n");
ext2_disk_write_block(2, (uint8_t *)BGD);
kprintf("Alright, we have an inode (%d), time to write it out to disk and make the file in the directory.\n", node_no);
free(bg_buffer);
return inode;
}
void ext2_disk_write_inode(ext2_inodetable_t * inode, uint32_t index) {
uint32_t group = index / ext2_disk_inodes_per_group;
if (group > BGDS) { return; }
uint32_t inode_table_block = BGD[group].inode_table;
inode -= group * ext2_disk_inodes_per_group;
uint32_t block_offset = ((index - 1) * SB->inode_size) / BLOCKSIZE;
uint32_t offset_in_block = (index - 1) - block_offset * (BLOCKSIZE / SB->inode_size);
ext2_inodetable_t * inodet = malloc(BLOCKSIZE);
/* Read the current table block */
ext2_disk_read_block(inode_table_block + block_offset, (uint8_t *)inodet);
memcpy(&inodet[offset_in_block], inode, sizeof(ext2_inodetable_t));
ext2_disk_write_block(inode_table_block + block_offset, (uint8_t *)inodet);
}
ext2_dir_t * ext2_disk_direntry(ext2_inodetable_t * inode, uint32_t index) {
uint8_t * block = malloc(BLOCKSIZE);
ext2_disk_inode_block(inode,0,block);
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) {
ext2_dir_t * out = malloc(d_ent->rec_len);
memcpy(out, d_ent, d_ent->rec_len);
free(block);
return out;
}
dir_offset += d_ent->rec_len;
dir_index++;
/* XXX: if dir_offest > BLOCKSIZE, next block!!! */
}
free(block);
return NULL;
}
ext2_inodetable_t * ext2_disk_inode(uint32_t inode) {
uint32_t group = inode / ext2_disk_inodes_per_group;
if (group > BGDS) { return NULL; }
uint32_t inode_table_block = BGD[group].inode_table;
inode -= group * ext2_disk_inodes_per_group;
uint32_t block_offset = ((inode - 1) * SB->inode_size) / BLOCKSIZE;
uint32_t offset_in_block = (inode - 1) - block_offset * (BLOCKSIZE / SB->inode_size);
uint8_t * buf = malloc(BLOCKSIZE);
ext2_inodetable_t * inodet = malloc(BLOCKSIZE);
ext2_disk_read_block(inode_table_block + block_offset, buf);
ext2_inodetable_t * inodes = (ext2_inodetable_t *)buf;
memcpy(inodet, &inodes[offset_in_block], sizeof(ext2_inodetable_t));
free(buf);
return inodet;
}
uint32_t read_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;
if (offset + size > inode->size) {
end = inode->size;
} else {
end = offset + size;
}
uint32_t start_block = offset / BLOCKSIZE;
uint32_t end_block = end / BLOCKSIZE;
uint32_t end_size = end % BLOCKSIZE;
uint32_t size_to_read = end - offset;
if (end_size == 0) { end_block--; }
if (start_block == end_block) {
void * buf = malloc(BLOCKSIZE);
ext2_disk_inode_block(inode, start_block, buf);
memcpy(buffer, (uint8_t *)(((uint32_t)buf) + offset % BLOCKSIZE), size_to_read);
free(buf);
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) {
void * buf = malloc(BLOCKSIZE);
ext2_disk_inode_block(inode, block_offset, buf);
memcpy(buffer, (uint8_t *)(((uint32_t)buf) + (offset % BLOCKSIZE)), (BLOCKSIZE - (offset % BLOCKSIZE)));
free(buf);
} else {
void * buf = malloc(BLOCKSIZE);
ext2_disk_inode_block(inode, block_offset, buf);
memcpy(buffer + BLOCKSIZE * blocks_read - (offset % BLOCKSIZE), buf, BLOCKSIZE);
free(buf);
}
blocks_read++;
}
void * buf = malloc(BLOCKSIZE);
ext2_disk_inode_block(inode, end_block, buf);
memcpy(buffer + BLOCKSIZE * blocks_read - (offset % BLOCKSIZE), buf, end_size);
free(buf);
}
free(inode);
return size_to_read;
}
void
open_ext2_disk (
fs_node_t *node,
uint8_t read,
uint8_t write
) {
// woosh
}
struct dirent *
readdir_ext2_disk (
fs_node_t *node,
uint32_t index
) {
ext2_inodetable_t * inode = ext2_disk_inode(node->inode);
assert(inode->mode & EXT2_S_IFDIR);
ext2_dir_t * direntry = ext2_disk_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;
free(direntry);
free(inode);
return dirent;
}
fs_node_t *
finddir_ext2_disk (
fs_node_t *node,
char *name
) {
/*
* Find the actual inode in the ramdisk image for the requested file
*/
ext2_inodetable_t * inode = ext2_disk_inode(node->inode);
assert(inode->mode & EXT2_S_IFDIR);
void * block = malloc(BLOCKSIZE);
ext2_dir_t * direntry = NULL;
ext2_disk_inode_block(inode, 0, block);
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 (strlen(name) != d_ent->name_len) {
dir_offset += d_ent->rec_len;
continue;
}
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 = malloc(d_ent->rec_len);
memcpy(direntry, d_ent, d_ent->rec_len);
break;
}
free(dname);
dir_offset += d_ent->rec_len;
}
free(inode);
free(block);
if (!direntry) {
/*
* We could not find the requested entry in this directory.
*/
return NULL;
}
fs_node_t * outnode = malloc(sizeof(fs_node_t));
inode = ext2_disk_inode(direntry->inode);
ext2_disk_node_from_file(inode, direntry, outnode);
free(inode);
return outnode;
}
uint32_t ext2_disk_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_ext2_disk;
fnode->write = NULL; //write_ext2_disk;
fnode->open = open_ext2_disk;
fnode->close = NULL; //close_ext2_disk;
fnode->readdir = readdir_ext2_disk;
fnode->finddir = finddir_ext2_disk;
return 1;
}
uint32_t ext2_disk_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_ext2_disk;
fnode->write = NULL; //write_ext2_disk;
fnode->open = open_ext2_disk;
fnode->close = NULL; //close_ext2_disk;
fnode->readdir = readdir_ext2_disk;
fnode->finddir = finddir_ext2_disk;
return 1;
}
void ext2_disk_read_superblock() {
kprintf("Volume '%s'\n", SB->volume_name);
kprintf("%d inodes\n", SB->inodes_count);
kprintf("%d blocks\n", SB->blocks_count);
kprintf("%d free blocks\n", SB->free_blocks_count);
kprintf("0x%x last mount time\n", SB->mtime);
kprintf("0x%x last write time\n", SB->wtime);
kprintf("Mounted %d times.\n", SB->mnt_count);
kprintf("0x%x\n", SB->magic);
}
void ext2_disk_mount() {
DC = malloc(sizeof(ext2_disk_cache_entry_t) * CACHEENTRIES);
SB = malloc(BLOCKSIZE);
ext2_disk_read_block(1, (uint8_t *)SB);
assert(SB->magic == EXT2_SUPER_MAGIC);
if (SB->inode_size == 0) {
SB->inode_size = 128;
}
BGDS = SB->blocks_count / SB->blocks_per_group;
ext2_disk_inodes_per_group = SB->inodes_count / BGDS;
BGD = malloc(BLOCKSIZE);
ext2_disk_root_block = malloc(BLOCKSIZE);
ext2_disk_read_block(2, (uint8_t *)BGD);
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
char bg_buffer[BLOCKSIZE];
for (uint32_t i = 0; i < BGDS; ++i) {
kprintf("Block Group Descriptor #%d @ %d\n", i, 2 + i * SB->blocks_per_group);
kprintf("\tBlock Bitmap @ %d\n", BGD[i].block_bitmap); {
kprintf("\t\tExamining block bitmap at %d\n", BGD[i].block_bitmap);
ext2_disk_read_block(BGD[i].block_bitmap, (uint8_t *)bg_buffer);
uint32_t j = 0;
while (BLOCKBIT(j)) {
++j;
}
kprintf("\t\tFirst free block in group is %d\n", j + BGD[i].block_bitmap - 2);
}
kprintf("\tInode Bitmap @ %d\n", BGD[i].inode_bitmap); {
kprintf("\t\tExamining inode bitmap at %d\n", BGD[i].inode_bitmap);
ext2_disk_read_block(BGD[i].inode_bitmap, (uint8_t *)bg_buffer);
uint32_t j = 0;
while (BLOCKBIT(j)) {
++j;
}
kprintf("\t\tFirst free inode in group is %d\n", j + ext2_disk_inodes_per_group * i + 1);
}
kprintf("\tInode Table @ %d\n", BGD[i].inode_table);
kprintf("\tFree Blocks = %d\n", BGD[i].free_blocks_count);
kprintf("\tFree Inodes = %d\n", BGD[i].free_inodes_count);
}
#endif
ext2_inodetable_t * root_inode = ext2_disk_inode(2);
RN = (fs_node_t *)malloc(sizeof(fs_node_t));
assert(ext2_disk_node_root(root_inode, RN));
fs_root = RN;
LOG(INFO,"Mounted EXT2 disk, root VFS node is at 0x%x", RN);
}
void ext2_disk_forget_superblock() {
free(SB);
}