int ext2_truncate(inode_t *inode, off_t off) {
__u32 size = off;
ext2_fs_instance_t *instance = (ext2_fs_instance_t*)inode->i_instance;
struct ext2_inode *einode = read_inode(instance, inode->i_ino);
if (einode) {
__u32 n_blk;
if (size > 0) {
n_blk = (size - 1) / (1024 << instance->superblock.s_log_block_size) + 1;
} else {
n_blk = 1;
}
__u32 addr = get_data_block (instance,einode, n_blk);;
if (addr) {
while (addr) {
if (off <= 0) {
free_block(instance, addr / (1024 << instance->superblock.s_log_block_size));
} else {
off -= 1024 << instance->superblock.s_log_block_size;
}
n_blk++;
addr = get_data_block (instance,einode, n_blk);
}
} else {
while (off > 0) {
set_block_inode_data(instance, einode, n_blk, alloc_block(instance));
n_blk++;
off -= 1024 << instance->superblock.s_log_block_size;
}
}
einode->i_size = size;
write_inode(instance, inode->i_ino, einode);
ext2inode_2_inode(inode, inode->i_instance, inode->i_ino, einode);
return 0;
}
return -ENOENT;
}
int ext2_truncate(inode_t *inode, off_t off) {
uint32_t size = off;
ext2_fs_instance_t *instance = (ext2_fs_instance_t*)inode->i_instance;
struct ext2_inode *einode = read_inode(instance, inode->i_ino);
if (einode) {
// TODO vérifier le bon fonctionnement.
int n_blk;
if (size > 0) {
n_blk = (size - 1) / (1024 << instance->superblock.s_log_block_size) + 1;
} else {
n_blk = 1;
}
int addr = addr_inode_data2(instance, einode, n_blk);
if (addr) {
// 1er cas : off est plus petit que la taille du fichier.
while (addr) {
if (off <= 0) {
free_block(instance, addr / (1024 << instance->superblock.s_log_block_size));
} else {
off -= 1024 << instance->superblock.s_log_block_size;
}
n_blk++;
addr = addr_inode_data2(instance, einode, n_blk);
}
} else {
// 2er cas : off est plus grand.
while (off > 0) {
set_block_inode_data(instance, einode, n_blk, alloc_block(instance));
n_blk++;
off -= 1024 << instance->superblock.s_log_block_size;
}
}
einode->i_size = size;
write_inode(instance, inode->i_ino, einode);
ext2inode_2_inode(inode, inode->i_instance, inode->i_ino, einode);
return 0;
}
return -ENOENT;
}
int ext2_write(open_file_descriptor * ofd, const void *buf, size_t size) {
if ((ofd->flags & O_ACCMODE) == O_RDONLY) {
return 0;
}
int inode = ofd->inode->i_ino;
if (inode >= 0) {
ext2_fs_instance_t *instance = (ext2_fs_instance_t*) ofd->fs_instance;
struct ext2_inode *einode = read_inode(instance, inode);
if (einode != NULL) {
unsigned int offset;
if (ofd->flags & O_APPEND) {
offset = einode->i_size;
} else {
offset = ofd->current_octet;
}
int count = 0;
__u32 n_blk = 0;
int off = offset;
while (off >= (1024 << instance->superblock.s_log_block_size)) {
if (get_data_block (instance,einode, n_blk) == 0) {
int addr = alloc_block(instance);
set_block_inode_data(instance, einode, n_blk, addr);
}
off -= 1024 << instance->superblock.s_log_block_size;
n_blk++;
}
while (size > 0) {
__u32 addr = get_data_block (instance,einode, n_blk);
if (addr == 0) {
addr = alloc_block(instance);
set_block_inode_data(instance, einode, n_blk, addr);
addr *= (1024 << instance->superblock.s_log_block_size);
}
addr += off;
size_t size2 = (1024 << instance->superblock.s_log_block_size) - off;
off = 0;
if (size2 > size) {
size2 = size;
}
instance->write_data(instance->super.device, ((char*)buf) + count, size2, addr);
size -= size2;
count += size2;
n_blk++;
}
einode->i_size = max(einode->i_size, offset + count);
// struct timeval tv;
// gettimeofday(&tv, NULL);
// einode.i_mtime = tv.tv_sec;
write_inode(instance, inode, einode);
return count;
} else {
return -ENOENT;
}
return size;
} else {
return inode;
}
}
