void sfs_read(int sfs_handle, char *fn)
{
int i, block_i, already_read, rem_to_read, to_read;
sfs_file_entry_t fe;
if ((i = sfs_lookup(sfs_handle, fn, &fe)) == -1)
{
printf("File %s doesn't exist\n", fn);
return;
}
if (!(fe.perms & 04))
{
printf("File %s doesn't have read permissions\n", fn);
return;
}
already_read = 0;
rem_to_read = fe.size;
for (block_i = 0; block_i < SIMULA_FS_DATA_BLOCK_CNT; block_i++)
{
if (!fe.blocks[block_i]) break;
to_read = (rem_to_read >= sb.block_size) ? sb.block_size : rem_to_read;
lseek(sfs_handle, fe.blocks[block_i] * sb.block_size, SEEK_SET);
read(sfs_handle, block, to_read);
write(1, block, to_read);
already_read += to_read;
rem_to_read -= to_read;
if (!rem_to_read) break;
}
}
int sfs_remove(sfs_info_t *info, char *fn)
{
int vfs_ino, block_i;
sfs_file_entry_t fe;
if ((vfs_ino = sfs_lookup(info, fn, &fe)) == -1)
{
printk(KERN_ERR "File %s doesn't exist\n", fn);
return -1;
}
/* Free up all allocated blocks, if any */
for (block_i = 0; block_i < SIMULA_FS_DATA_BLOCK_CNT; block_i++)
{
if (!fe.blocks[block_i])
{
break;
}
sfs_put_data_block(info, fe.blocks[block_i]);
}
memset(&fe, 0, sizeof(sfs_file_entry_t));
if (write_to_real_sfs(info, info->sb.entry_table_block_start, V2S_INODE_NUM(vfs_ino) * sizeof(sfs_file_entry_t), &fe, sizeof(sfs_file_entry_t)) == -1)
return -1;
return vfs_ino;
}
void sfs_write(int sfs_handle, char *fn)
{
int i, cur_read_i, to_read, cur_read, total_size, block_i, free_i;
sfs_file_entry_t fe;
if ((i = sfs_lookup(sfs_handle, fn, &fe)) == -1)
{
printf("File %s doesn't exist\n", fn);
return;
}
cur_read_i = 0;
to_read = sb.block_size;
total_size = 0;
block_i = 0;
while ((cur_read = read(0, block + cur_read_i, to_read)) > 0)
{
if (cur_read == to_read)
{
/* Write this block */
if (block_i == SIMULA_FS_DATA_BLOCK_CNT)
break; /* File size limit */
if ((free_i = get_data_block(sfs_handle)) == -1)
break; /* File system full */
lseek(sfs_handle, free_i * sb.block_size, SEEK_SET);
write(sfs_handle, block, sb.block_size);
fe.blocks[block_i] = free_i;
block_i++;
total_size += sb.block_size;
/* Reset various variables */
cur_read_i = 0;
to_read = sb.block_size;
}
else
{
cur_read_i += cur_read;
to_read -= cur_read;
}
}
if ((cur_read <= 0) && (cur_read_i))
{
/* Write this partial block */
if ((block_i != SIMULA_FS_DATA_BLOCK_CNT) &&
((fe.blocks[block_i] = get_data_block(sfs_handle)) != -1))
{
lseek(sfs_handle, fe.blocks[block_i] * sb.block_size, SEEK_SET);
write(sfs_handle, block, cur_read_i);
total_size += cur_read_i;
}
}
fe.size = total_size;
fe.timestamp = time(NULL);
lseek(sfs_handle, sb.entry_table_block_start * sb.block_size + i * sb.entry_size, SEEK_SET);
write(sfs_handle, &fe, sizeof(sfs_file_entry_t));
}
void sfs_remove(int sfs_handle, char *fn)
{
int i;
sfs_file_entry_t fe;
if ((i = sfs_lookup(sfs_handle, fn, &fe)) == -1)
{
printf("File %s doesn't exist\n", fn);
return;
}
memset(&fe, 0, sizeof(sfs_file_entry_t));
lseek(sfs_handle, sb.entry_table_block_start * sb.block_size + i * sb.entry_size, SEEK_SET);
write(sfs_handle, &fe, sizeof(sfs_file_entry_t));
}
void sfs_update(int sfs_handle, char *fn, int *size, int update_ts, int *perms)
{
int i;
sfs_file_entry_t fe;
if ((i = sfs_lookup(sfs_handle, fn, &fe)) == -1)
{
printf("File %s doesn't exist\n", fn);
return;
}
if (size) fe.size = *size;
if (update_ts) fe.timestamp = time(NULL);
if (perms && (*perms <= 07)) fe.perms = *perms;
lseek(sfs_handle, sb.entry_table_block_start * sb.block_size + i * sb.entry_size, SEEK_SET);
write(sfs_handle, &fe, sizeof(sfs_file_entry_t));
}
void sfs_remove(int sfs_handle, char *fn)
{
int i, block_i;
sfs_file_entry_t fe;
if ((i = sfs_lookup(sfs_handle, fn, &fe)) == -1)
{
printf("File %s doesn't exist\n", fn);
return;
}
/* Free up all allocated blocks, if any */
for (block_i = 0; block_i < SIMULA_FS_DATA_BLOCK_CNT; block_i++)
{
if (!fe.blocks[block_i])
{
break;
}
put_data_block(sfs_handle, fe.blocks[block_i]);
}
memset(&fe, 0, sizeof(sfs_file_entry_t));
lseek(sfs_handle, sb.entry_table_block_start * sb.block_size + i * sb.entry_size, SEEK_SET);
write(sfs_handle, &fe, sizeof(sfs_file_entry_t));
}
