static int isNameUnique (uint fsdev, dinode_t *dinode, char *name, u_int namelen)
{
int i;
for (i=0; i<NUM_DIRECT; i++) {
if (dinode->directBlocks[i]) {
struct bc_entry *buf = bc_lookup (fsdev, dinode->directBlocks[i]);
if (buf == NULL) {
printf ("WARN: isNameUnique fails because one of the directory blocks is not resident.\n");
} else if (nameconflict ((char *) (KERNBASE + (((u32)buf->buf_ppn) << PGSHIFT)), name, namelen)) {
printf ("name conflict found\n");
return (0);
}
}
}
return (1);
}
bool bc_read(block_sector_t sector_idx, void *buffer, off_t bytes_read, int chunck_size, int sector_ofs)
{
/* find the buffer cache entry of which block_sector_t is equal to sector_idx */
struct buffer_head *sector_buffer = bc_lookup(sector_idx);
/* if can't find the buffer cache entry */
if(sector_buffer == NULL)
{
sector_buffer = bc_select_victim();
/* update buffer_head and read the data from disk */
sector_buffer->sector = sector_idx;
sector_buffer->is_used = true;
block_read(fs_device, sector_idx, sector_buffer->data);
}
/* updata the clock bit */
sector_buffer->clock_bit = true;
/* read data from buffer cache */
memcpy(buffer + bytes_read, sector_buffer->data + sector_ofs, chunck_size);
return true;
}
bool bc_write(block_sector_t sector_idx, void *buffer, off_t bytes_written, int chunck_size, int sector_ofs)
{
/* find the buffer cache entry of which block_sector_t is equal to sector_idx */
struct buffer_head *sector_buffer = bc_lookup(sector_idx);
/* if can't find the buffer cache entry */
if(sector_buffer == NULL)
{
sector_buffer = bc_select_victim();
/* update buffer_head and read the data from disk */
sector_buffer->sector = sector_idx;
sector_buffer->is_used = true;
block_read(fs_device, sector_idx, sector_buffer->data);
}
/* write the data to buffer_cache */
memcpy(sector_buffer->data + sector_ofs, buffer + bytes_written, chunck_size);
/* update the */
lock_acquire(§or_buffer->buffer_lock);
sector_buffer->clock_bit = true;
sector_buffer->dirty = true;
lock_release(§or_buffer->buffer_lock);
return true;
}
void bc_check(char *msg, db_t db) {
printf("msg = %s\n", msg);
if(bc_lookup(XN_DEV, db))
printf("db %ld: in bc %p\n", db, bc_lookup(XN_DEV, db));
}
