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toaruos/kernel/fs/ext2_disk.c
Kevin Lange 8dd2686b40 Really hack VFS implementation
2013-03-15 00:20:55 -07:00

1119 lines
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/* vim: tabstop=4 shiftwidth=4 noexpandtab
*/
#include <system.h>
#include <ext2.h>
#include <fs.h>
#include <logging.h>
#define EXT2_DEBUG_BLOCK_DESCRIPTORS 1
uint32_t BLOCKSIZE = 1024;
uint32_t CACHEENTRIES = 10240;
uint32_t PTRS_PER_BLOCK = 256;
#define SECTORSIZE 512
#define DISK_PORT 0x1F0
typedef struct {
uint32_t block_no;
uint32_t last_use;
uint8_t dirty;
uint8_t *block;
} ext2_disk_cache_entry_t;
ext2_disk_cache_entry_t *ext2_disk_cache = NULL; // LSU block cache
ext2_superblock_t *ext2_disk_superblock = NULL;
ext2_bgdescriptor_t *ext2_disk_root_block = NULL;
fs_node_t *ext2_root_fsnode = NULL;
/** Prototypes */
uint32_t ext2_disk_node_from_file(ext2_inodetable_t *inode, ext2_dir_t *direntry, fs_node_t *fnode);
ext2_inodetable_t *ext2_disk_inode(uint32_t inode);
ext2_inodetable_t *ext2_disk_alloc_inode(ext2_inodetable_t *parent, uint32_t no, char *name, uint16_t mode, uint32_t *inode_no);
fs_node_t *finddir_ext2_disk(fs_node_t *node, char *name);
void insertdir_ext2_disk(ext2_inodetable_t *p_node, uint32_t no, uint32_t inode, char *name, uint8_t type);
void ext2_disk_write_inode(ext2_inodetable_t *inode, uint32_t index);
uint32_t write_ext2_disk(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer);
uint32_t read_ext2_disk(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer);
uint32_t ext2_disk_inodes_per_group = 0;
uint32_t ext2_disk_bg_descriptors = 0; // Total number of block groups
uint32_t ext2_offset = 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) >> 3)] & (1 << (((n) % 8))))
#define BLOCKBYTE(n) (bg_buffer[((n) >> 3)])
#define SETBIT(n) (1 << (((n) % 8)))
static uint32_t btos(uint32_t block) {
return ext2_offset + block * (BLOCKSIZE / SECTORSIZE);
}
static uint8_t volatile lock;
static uint32_t _now = 1;
static uint32_t ext2_time() {
return _now++;
}
void ext2_flush_dirty(uint32_t ent_no) {
// write out to the disk
for (uint32_t i = 0; i < BLOCKSIZE / SECTORSIZE; ++i) {
ide_write_sector_retry(DISK_PORT, 0, btos(DC[ent_no].block_no) + i, (uint8_t *)((uint32_t)DC[ent_no].block + SECTORSIZE * i));
}
DC[ent_no].dirty = 0;
}
void ext2_disk_read_block(uint32_t block_no, uint8_t *buf) {
if (!block_no) return;
spin_lock(&lock);
if (!DC) {
/* There is not disk cache, do a raw read */
for (uint32_t i = 0; i < BLOCKSIZE / SECTORSIZE; ++i) {
ide_read_sector(DISK_PORT, 0, btos(block_no) + i, (uint8_t *)((uint32_t)buf + SECTORSIZE * i));
}
spin_unlock(&lock);
return;
}
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 = ext2_time();
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;
}
}
for (uint32_t i = 0; i < BLOCKSIZE / SECTORSIZE; ++i) {
ide_read_sector(DISK_PORT, 0, btos(block_no) + i, (uint8_t *)((uint32_t)(DC[oldest].block) + SECTORSIZE * i));
}
if (DC[oldest].dirty) {
ext2_flush_dirty(oldest);
}
memcpy(buf, DC[oldest].block, BLOCKSIZE);
DC[oldest].block_no = block_no;
DC[oldest].last_use = ext2_time();
DC[oldest].dirty = 0;
spin_unlock(&lock);
}
void ext2_disk_write_block(uint32_t block_no, uint8_t *buf) {
if (!block_no) {
kprintf("[kernel/ext2] block_no = 0?\n");
kprintf("[kernel/ext2] Investigate the call before this, you have done something terrible!\n");
return;
}
spin_lock(&lock);
// update the cache
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 = ext2_time();
DC[i].dirty = 1;
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;
}
}
if (DC[oldest].dirty) {
ext2_flush_dirty(oldest);
}
memcpy(DC[oldest].block, buf, BLOCKSIZE);
DC[oldest].block_no = block_no;
DC[oldest].last_use = ext2_time();
DC[oldest].dirty = 1;
spin_unlock(&lock);
}
void ext2_set_real_block(ext2_inodetable_t *inode, uint32_t block, uint32_t real) {
if (block < 12) {
inode->block[block] = real;
return;
} else if (block < 12 + PTRS_PER_BLOCK) {
uint8_t *tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[12], tmp);
((uint32_t *)tmp)[block - 12] = real;
ext2_disk_write_block(inode->block[12], tmp);
free(tmp);
return;
} else if (block < 12 + PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK) {
uint32_t a = block - 12;
uint32_t b = a - PTRS_PER_BLOCK;
uint32_t c = b / PTRS_PER_BLOCK;
uint32_t d = b - c * PTRS_PER_BLOCK;
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);
((uint32_t *)tmp)[d] = real;
ext2_disk_write_block(nblock, tmp);
free(tmp);
return;
} else if (block < 12 + PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK * PTRS_PER_BLOCK) {
uint32_t a = block - 12;
uint32_t b = a - PTRS_PER_BLOCK;
uint32_t c = b - PTRS_PER_BLOCK * PTRS_PER_BLOCK;
uint32_t d = c / (PTRS_PER_BLOCK * PTRS_PER_BLOCK);
uint32_t e = c - d * PTRS_PER_BLOCK * PTRS_PER_BLOCK;
uint32_t f = e / PTRS_PER_BLOCK;
uint32_t g = e - f * PTRS_PER_BLOCK;
uint8_t *tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[14], tmp);
uint32_t nblock = ((uint32_t *)tmp)[d];
ext2_disk_read_block(nblock, tmp);
nblock = ((uint32_t *)tmp)[f];
ext2_disk_read_block(nblock, tmp);
((uint32_t *)tmp)[g] = nblock;
ext2_disk_write_block(nblock, tmp);
free(tmp);
return;
}
HALT_AND_CATCH_FIRE("Attempted to set a file block that was too high :(", NULL);
}
/**
* Return the actual block number represented by the 'block'th block
* in the 'inode'.
*/
uint32_t ext2_get_real_block(ext2_inodetable_t *inode, uint32_t block) {
if (block < 12) {
return inode->block[block];
} else if (block < 12 + PTRS_PER_BLOCK) {
uint8_t *tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[12], tmp);
uint32_t nblock = ((uint32_t *)tmp)[block - 12];
free(tmp);
return nblock;
} else if (block < 12 + PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK) {
uint32_t a = block - 12;
uint32_t b = a - PTRS_PER_BLOCK;
uint32_t c = b / PTRS_PER_BLOCK;
uint32_t d = b - c * PTRS_PER_BLOCK;
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);
return nblock;
} else if (block < 12 + PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK + PTRS_PER_BLOCK * PTRS_PER_BLOCK * PTRS_PER_BLOCK) {
uint32_t a = block - 12;
uint32_t b = a - PTRS_PER_BLOCK;
uint32_t c = b - PTRS_PER_BLOCK * PTRS_PER_BLOCK;
uint32_t d = c / (PTRS_PER_BLOCK * PTRS_PER_BLOCK);
uint32_t e = c - d * PTRS_PER_BLOCK * PTRS_PER_BLOCK;
uint32_t f = e / PTRS_PER_BLOCK;
uint32_t g = e - f * PTRS_PER_BLOCK;
uint8_t *tmp = malloc(BLOCKSIZE);
ext2_disk_read_block(inode->block[14], tmp);
uint32_t nblock = ((uint32_t *)tmp)[d];
ext2_disk_read_block(nblock, tmp);
nblock = ((uint32_t *)tmp)[f];
ext2_disk_read_block(nblock, tmp);
nblock = ((uint32_t *)tmp)[g];
free(tmp);
return nblock;
}
HALT_AND_CATCH_FIRE("Attempted to get a file block that was too high :(", NULL);
return 0;
}
/**
* 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 inode_no, uint32_t block) {
debug_print(NOTICE, "allocating block %d for inode #%d", block, inode_no);
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) {
debug_print(CRITICAL, "No available blocks!");
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, inode_no);
}
/**
* Read the 'block'th block within an inode 'inode', and put it into
* the buffer 'buf'. In other words, this function reads the actual file
* content. 'no' is the inode number of 'inode'.
* @return the actual block number read from.
*/
uint32_t ext2_disk_inode_read_block(ext2_inodetable_t *inode, uint32_t no, uint32_t block, uint8_t *buf) {
// if the memory for 'block'th block has not been allocated to this inode, we need to
// allocate the memory first using block bitmap.
if (block >= inode->blocks) {
/* Invalid block requested, return 0s */
memset(buf, 0x00, BLOCKSIZE);
debug_print(ERROR, "An invalid inode block [%d] was requested [have %d]", block, inode->blocks);
return 0;
}
// The real work to read a block from an inode.
uint32_t real_block = ext2_get_real_block(inode, block);
ext2_disk_read_block(real_block, buf);
return real_block;
}
/**
* Write to the 'block'th block within an inode 'inode' from the buffer 'buf'.
* In other words, this function writes to the actual file content.
* @return the actual block number read from.
*/
uint32_t ext2_disk_inode_write_block(ext2_inodetable_t *inode, uint32_t inode_no, uint32_t block, uint8_t *buf) {
/* We must allocate blocks up to this point to account for unused space in the middle. */
while (block >= inode->blocks) {
ext2_disk_inode_alloc_block(inode, inode_no, inode->blocks);
if (block != inode->blocks - 1) {
/* Clear the block */
uint32_t real_block = ext2_get_real_block(inode, inode->blocks - 1);
uint8_t * empty = malloc(BLOCKSIZE);
memset(empty, 0x00, BLOCKSIZE);
ext2_disk_write_block(real_block, empty);
free(empty);
}
}
// The real work to write to a block of an inode.
uint32_t real_block = ext2_get_real_block(inode, block);
debug_print(INFO, "virtual block %d maps to real block %d", block, real_block);
ext2_disk_write_block(real_block, buf);
return real_block;
}
/**
* Create a new, regular, and empty file under directory 'parent'.
*/
void ext2_create(fs_node_t *parent, char *name, uint16_t permission) {
debug_print(NOTICE, "Creating file %s", name);
uint16_t mode = permission | EXT2_S_IFREG;
ext2_inodetable_t *parent_inode = ext2_disk_inode(parent->inode);
// Check to make sure no same name in the parent dir
fs_node_t *b_exist = finddir_ext2_disk(parent, name);
if (b_exist) {
debug_print(WARNING, "File already exists!");
free(b_exist);
free(parent_inode);
return;
}
free(b_exist);
// Create the inode under 'parent'
uint32_t inode_no;
ext2_inodetable_t *inode = ext2_disk_alloc_inode(parent_inode, parent->inode, name, mode, &inode_no);
free(parent_inode);
if (inode == NULL) {
debug_print(ERROR, "Failed to create file (inode allocation failed)");
return;
}
free(inode);
}
/**
* Make a new directory. 'name' consists the name for the new directory
* to be created using 'permission' under 'parent' directory.
* Message will be displayed in the terminal for success or failure.
*/
void ext2_mkdir(fs_node_t *parent, char *name, uint16_t permission) {
uint16_t mode = permission | EXT2_S_IFDIR;
ext2_inodetable_t *parent_inode = ext2_disk_inode(parent->inode);
// Check to make sure no same name in the parent dir
fs_node_t *b_exist = finddir_ext2_disk(parent, name);
if (b_exist) {
debug_print(WARNING, "%s already exists", name);
free(b_exist);
free(parent_inode);
return;
}
free(b_exist);
// Create the inode under 'parent'
uint32_t inode_no;
ext2_inodetable_t *inode = ext2_disk_alloc_inode(parent_inode, parent->inode, name, mode, &inode_no);
free(parent_inode);
if (inode == NULL) {
debug_print(ERROR, "Could not create %s", name);
return;
}
// Init this newly created dir, put '.' and '..' into it.
// Here we pass in 0 as the inode number for '.' and '..' because the
// 'cd' command can handle them correctly, so it does not matter.
insertdir_ext2_disk(inode, inode_no, 0, ".", 2);
insertdir_ext2_disk(inode, inode_no, 0, "..", 2);
free(inode);
}
uint8_t mode_to_filetype(uint16_t mode) {
uint16_t ftype = mode & 0xF000;
switch (ftype) {
case EXT2_S_IFREG:
return 1;
case EXT2_S_IFDIR:
return 2;
case EXT2_S_IFCHR:
return 3;
case EXT2_S_IFBLK:
return 4;
case EXT2_S_IFIFO:
return 5;
case EXT2_S_IFSOCK:
return 6;
case EXT2_S_IFLNK:
return 7;
}
// File type is unknown
return 0;
}
/**
* 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;
}
/**
* Return the 'index'th directory entry in the directory represented by 'inode'.
* Caller should free the memory.
*/
ext2_dir_t *ext2_disk_direntry(ext2_inodetable_t *inode, uint32_t no, uint32_t index) {
uint8_t *block = malloc(BLOCKSIZE);
uint8_t block_nr = 0;
ext2_disk_inode_read_block(inode, no, block_nr, block);
uint32_t dir_offset = 0;
uint32_t total_offset = 0;
uint32_t dir_index = 0;
while (total_offset < inode->size && dir_index <= index) {
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;
total_offset += d_ent->rec_len;
dir_index++;
// 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(inode, no, block_nr, block);
}
}
free(block);
return NULL;
}
/**
* Return the inode object on disk representing 'inode'th inode.
* Caller should free the memory.
*/
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; // adjust index within 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(SB->inode_size);
ext2_disk_read_block(inode_table_block + block_offset, buf);
ext2_inodetable_t *inodes = (ext2_inodetable_t *)buf;
memcpy(inodet, (uint8_t *)((uint32_t)inodes + offset_in_block * SB->inode_size), SB->inode_size);
free(buf);
return inodet;
}
/**
* Write the 'inode' into the inode table at position 'index'.
*/
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;
index -= group * ext2_disk_inodes_per_group; // adjust index within 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((uint8_t *)((uint32_t)inodet + offset_in_block * SB->inode_size), inode, SB->inode_size);
ext2_disk_write_block(inode_table_block + block_offset, (uint8_t *)inodet);
free(inodet);
}
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;
}
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 - end_block * 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_read_block(inode, node->inode, start_block, buf);
memcpy(buffer, (uint8_t *)(((uint32_t)buf) + (offset % BLOCKSIZE)), size_to_read);
free(buf);
free(inode);
return size_to_read;
} 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(buffer, (uint8_t *)(((uint32_t)buf) + (offset % BLOCKSIZE)), BLOCKSIZE - (offset % BLOCKSIZE));
free(buf);
} else {
void *buf = malloc(BLOCKSIZE);
ext2_disk_inode_read_block(inode, node->inode, block_offset, buf);
memcpy(buffer + BLOCKSIZE * blocks_read - (offset % BLOCKSIZE), buf, BLOCKSIZE);
free(buf);
}
}
void *buf = malloc(BLOCKSIZE);
ext2_disk_inode_read_block(inode, node->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) {
/* Nothing to do here */
}
void
close_ext2_disk(fs_node_t *node) {
/* Nothing to do here */
}
/**
* Return the 'index'th entry in the directory 'node'.
* Caller should free the memory.
*/
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, node->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;
}
/**
* 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);
}
/**
* Find the actual inode in the ramdisk image for the requested file.
*/
fs_node_t *finddir_ext2_disk(fs_node_t *node, char *name) {
ext2_inodetable_t *inode = ext2_disk_inode(node->inode);
assert(inode->mode & EXT2_S_IFDIR);
void *block = malloc(BLOCKSIZE);
ext2_dir_t *direntry = NULL;
uint8_t block_nr = 0;
ext2_disk_inode_read_block(inode, node->inode, block_nr, block);
uint32_t dir_offset = 0;
uint32_t total_offset = 0;
// Look through the requested entries until we find what we're looking for
while (total_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;
total_offset += d_ent->rec_len;
// move on to the next block of this directory if need.
if (dir_offset >= BLOCKSIZE) {
block_nr++;
dir_offset -= BLOCKSIZE;
ext2_disk_inode_read_block(inode, node->inode, block_nr, block);
}
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;
total_offset += d_ent->rec_len;
// move on to the next block of this directory if need.
if (dir_offset >= BLOCKSIZE) {
block_nr++;
dir_offset -= BLOCKSIZE;
ext2_disk_inode_read_block(inode, node->inode, block_nr, block);
}
}
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);
if (!ext2_disk_node_from_file(inode, direntry, outnode)) {
debug_print(CRITICAL, "Oh dear. Couldn't allocate the outnode?");
}
free(direntry);
free(inode);
return outnode;
}
/**
* Initialize in-memory struct 'fnode' using on-disk structs 'inode' and 'direntry'.
*/
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;
fnode->create = NULL;
fnode->mkdir = NULL;
}
if ((inode->mode & EXT2_S_IFDIR) == EXT2_S_IFDIR) {
fnode->flags |= FS_DIRECTORY;
fnode->create = ext2_create;
fnode->mkdir = ext2_mkdir;
}
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->atime = inode->atime;
fnode->mtime = inode->mtime;
fnode->ctime = inode->ctime;
debug_print(INFO, "file a/m/c times are %d/%d/%d", fnode->atime, fnode->mtime, fnode->ctime);
fnode->read = read_ext2_disk;
fnode->write = write_ext2_disk;
fnode->open = open_ext2_disk;
fnode->close = close_ext2_disk;
fnode->readdir = readdir_ext2_disk;
fnode->finddir = finddir_ext2_disk;
return 1;
}
/**
* Intiailize in-memory struct 'fnode' that represents "/" using 'inode'.
*/
uint32_t ext2_disk_node_root(ext2_inodetable_t *inode, fs_node_t *fnode) {
if (!fnode) {
return 0;
}
/* Information for root dir */
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) {
debug_print(CRITICAL, "The hell? Root appears to be a regular file.");
debug_print(CRITICAL, "This is probably very, very wrong.");
return 0;
}
if ((inode->mode & EXT2_S_IFDIR) == EXT2_S_IFDIR) {
fnode->flags |= FS_DIRECTORY;
fnode->create = ext2_create;
fnode->mkdir = ext2_mkdir;
} else {
debug_print(CRITICAL, "The hell? Root doesn't appear to be a directory.");
debug_print(CRITICAL, "This is probably very, very wrong.");
return 0;
}
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->atime = inode->atime;
fnode->mtime = inode->mtime;
fnode->ctime = inode->ctime;
fnode->read = read_ext2_disk;
fnode->write = write_ext2_disk;
fnode->open = open_ext2_disk;
fnode->close = close_ext2_disk;
fnode->readdir = readdir_ext2_disk;
fnode->finddir = finddir_ext2_disk;
return 1;
}
void ext2_disk_read_superblock() {
debug_print(NOTICE, "Volume '%s'", SB->volume_name);
debug_print(NOTICE, "%d inodes", SB->inodes_count);
debug_print(NOTICE, "%d blocks", SB->blocks_count);
debug_print(NOTICE, "%d free blocks", SB->free_blocks_count);
debug_print(NOTICE, "0x%x last mount time", SB->mtime);
debug_print(NOTICE, "0x%x last write time", SB->wtime);
debug_print(NOTICE, "Mounted %d times.", SB->mnt_count);
debug_print(NOTICE, "0x%x", SB->magic);
debug_print(NOTICE, "feature_incompat = 0x%x", SB->feature_incompat);
}
void ext2_disk_sync() {
spin_lock(&lock);
for (uint32_t i = 0; i < CACHEENTRIES; ++i) {
if (DC[i].dirty) {
ext2_flush_dirty(i);
}
}
spin_unlock(&lock);
}
void ext2_disk_mount(uint32_t offset_sector, uint32_t max_sector) {
debug_print(NOTICE, "Mounting EXT2 partition between sectors [%d:%d].", offset_sector, max_sector);
ext2_offset = offset_sector;
BLOCKSIZE = 1024;
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;
}
BLOCKSIZE = 1024 << SB->log_block_size;
if (BLOCKSIZE > 2048) {
CACHEENTRIES /= 4;
}
PTRS_PER_BLOCK = BLOCKSIZE / 4;
debug_print(NOTICE, "Log block size = %d -> %d", SB->log_block_size, BLOCKSIZE);
BGDS = SB->blocks_count / SB->blocks_per_group;
if (SB->blocks_per_group * BGDS < SB->blocks_count) {
BGDS += 1;
}
ext2_disk_inodes_per_group = SB->inodes_count / BGDS;
debug_print(NOTICE, "Allocating cache...");
DC = malloc(sizeof(ext2_disk_cache_entry_t) * CACHEENTRIES);
for (uint32_t i = 0; i < CACHEENTRIES; ++i) {
DC[i].block = malloc(BLOCKSIZE);
if (i % 128 == 0) {
debug_print(INFO, "Allocated cache block #%d", i+1);
}
}
debug_print(NOTICE, "Allocated cache.");
// load the block group descriptors
int bgd_block_span = sizeof(ext2_bgdescriptor_t) * BGDS / BLOCKSIZE + 1;
BGD = malloc(BLOCKSIZE * bgd_block_span);
debug_print(INFO, "bgd_block_span = %d", bgd_block_span);
int bgd_offset = 2;
if (BLOCKSIZE > 1024) {
bgd_offset = 1;
}
for (int i = 0; i < bgd_block_span; ++i) {
ext2_disk_read_block(bgd_offset + i, (uint8_t *)((uint32_t)BGD + BLOCKSIZE * i));
}
#if EXT2_DEBUG_BLOCK_DESCRIPTORS
char * bg_buffer = malloc(BLOCKSIZE * sizeof(char));
for (uint32_t i = 0; i < BGDS; ++i) {
debug_print(INFO, "Block Group Descriptor #%d @ %d", i, bgd_offset + i * SB->blocks_per_group);
debug_print(INFO, "\tBlock Bitmap @ %d", BGD[i].block_bitmap); {
debug_print(INFO, "\t\tExamining block bitmap at %d", BGD[i].block_bitmap);
ext2_disk_read_block(BGD[i].block_bitmap, (uint8_t *)bg_buffer);
uint32_t j = 0;
while (BLOCKBIT(j)) {
++j;
}
debug_print(INFO, "\t\tFirst free block in group is %d", j + BGD[i].block_bitmap - 2);
}
debug_print(INFO, "\tInode Bitmap @ %d", BGD[i].inode_bitmap); {
debug_print(INFO, "\t\tExamining inode bitmap at %d", BGD[i].inode_bitmap);
ext2_disk_read_block(BGD[i].inode_bitmap, (uint8_t *)bg_buffer);
uint32_t j = 0;
while (BLOCKBIT(j)) {
++j;
}
debug_print(INFO, "\t\tFirst free inode in group is %d", j + ext2_disk_inodes_per_group * i + 1);
}
debug_print(INFO, "\tInode Table @ %d", BGD[i].inode_table);
debug_print(INFO, "\tFree Blocks = %d", BGD[i].free_blocks_count);
debug_print(INFO, "\tFree Inodes = %d", BGD[i].free_inodes_count);
}
free(bg_buffer);
#endif
ext2_inodetable_t *root_inode = ext2_disk_inode(2);
RN = (fs_node_t *)malloc(sizeof(fs_node_t));
if (!ext2_disk_node_root(root_inode, RN)) {
debug_print(NOTICE, "Oh dear...");
}
debug_print(NOTICE, "Root file system is ready.");
vfs_mount("/", RN);
debug_print(NOTICE, "Mounted EXT2 disk, root VFS node is at 0x%x", RN);
}
void ext2_disk_forget_superblock() {
free(SB);
}
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