Finish lab 5.

fs/bc.c

@@ -31,6 +31,7 @@ bc_pgfault(struct UTrapframe *utf)
 {
 	void *addr = (void *) utf->utf_fault_va;
 	uint32_t blockno = ((uint32_t)addr - DISKMAP) / BLKSIZE;
+	uint32_t secno = blockno * (BLKSIZE / SECTSIZE);
 	int r;
 
 	// Check that the fault was within the block cache region
@@ -48,6 +49,11 @@ bc_pgfault(struct UTrapframe *utf)
 	// the disk.
 	//
 	// LAB 5: you code here:
+	addr = ROUNDDOWN(addr, PGSIZE);
+	if((r = sys_page_alloc(0, addr, PTE_U | PTE_W | PTE_P)) < 0)
+		panic("failed to allocate page for block cache");
+	if((r = ide_read(secno, addr, BLKSIZE / SECTSIZE)) < 0)
+		panic("failed to read from disk into block cache");
 
 	// Clear the dirty bit for the disk block page since we just read the
 	// block from disk
@@ -72,12 +78,21 @@ void
 flush_block(void *addr)
 {
 	uint32_t blockno = ((uint32_t)addr - DISKMAP) / BLKSIZE;
+	uint32_t secno = blockno * (BLKSIZE / SECTSIZE);
+	int r;
 
 	if (addr < (void*)DISKMAP || addr >= (void*)(DISKMAP + DISKSIZE))
 		panic("flush_block of bad va %08x", addr);
 
 	// LAB 5: Your code here.
-	panic("flush_block not implemented");
+	addr = ROUNDDOWN(addr, PGSIZE);
+	if(!(va_is_mapped(addr) && va_is_dirty(addr))) return;
+
+	if((r = ide_write(secno, addr, BLKSIZE / SECTSIZE)) < 0)
+		panic("failed to flush block into cache");
+
+	if((r = sys_page_map(0, addr, 0, addr, uvpt[PGNUM(addr)] & PTE_SYSCALL)) < 0)
+		panic("failed to remove dirty bit from page");
 }
 
 // Test that the block cache works, by smashing the superblock and

fs/fs.c

@@ -60,9 +60,15 @@ alloc_block(void)
 	// The bitmap consists of one or more blocks.  A single bitmap block
 	// contains the in-use bits for BLKBITSIZE blocks.  There are
 	// super->s_nblocks blocks in the disk altogether.
+	uint32_t* search = bitmap + 1;
+	for(uint32_t block = 1; block < super->s_nblocks; block++) {
+		if(bitmap[block / 32] & (1 << (block % 32))) {
+			bitmap[block / 32] &= ~(1 << (block % 32));
+			flush_block(&bitmap[block / 32]);
+			return block;
+		}
+	}
 
-	// LAB 5: Your code here.
-	panic("alloc_block not implemented");
 	return -E_NO_DISK;
 }
 
@@ -135,7 +141,23 @@ static int
 file_block_walk(struct File *f, uint32_t filebno, uint32_t **ppdiskbno, bool alloc)
 {
        // LAB 5: Your code here.
-       panic("file_block_walk not implemented");
+	int newblock;
+	if(filebno < NDIRECT) {
+		*ppdiskbno = &f->f_direct[filebno];
+		return 0;
+	} else if(filebno < NDIRECT + NINDIRECT) {
+		filebno -= NDIRECT;
+		if(!f->f_indirect) {
+			if(!alloc) return -E_NOT_FOUND;
+			if((newblock = alloc_block()) < 0) return newblock;
+			f->f_indirect = newblock;
+		}
+
+		uint32_t* indirect = diskaddr(f->f_indirect);
+		*ppdiskbno = &indirect[filebno];
+		return 0;
+	}
+	return -E_INVAL;
 }
 
 // Set *blk to the address in memory where the filebno'th
@@ -150,7 +172,19 @@ int
 file_get_block(struct File *f, uint32_t filebno, char **blk)
 {
        // LAB 5: Your code here.
-       panic("file_get_block not implemented");
+	uint32_t* blockno;
+	int r;
+
+	if ((r = file_block_walk(f, filebno, &blockno, 1)) < 0)
+		return r;
+
+	if(*blockno == 0) {
+		if((r = alloc_block()) < 0) return r;
+		*blockno = r;
+	}
+
+	*blk = diskaddr(*blockno);
+	return 0;
 }
 
 // Try to find a file named "name" in dir.  If so, set *file to it.

fs/serv.c

@@ -209,12 +209,20 @@ serve_read(envid_t envid, union Fsipc *ipc)
 {
 	struct Fsreq_read *req = &ipc->read;
 	struct Fsret_read *ret = &ipc->readRet;
+	struct OpenFile* open_file;
+	int r;
 
 	if (debug)
 		cprintf("serve_read %08x %08x %08x\n", envid, req->req_fileid, req->req_n);
 
-	// Lab 5: Your code here:
-	return 0;
+	if((r = openfile_lookup(envid, req->req_fileid, &open_file)) < 0)
+		return r;
+
+	if((r = file_read(open_file->o_file, ret->ret_buf, req->req_n, open_file->o_fd->fd_offset)) < 0)
+		return r;
+
+	open_file->o_fd->fd_offset += r;
+	return r;
 }
 
 
@@ -227,9 +235,17 @@ serve_write(envid_t envid, struct Fsreq_write *req)
 {
 	if (debug)
 		cprintf("serve_write %08x %08x %08x\n", envid, req->req_fileid, req->req_n);
+	
+	struct OpenFile* open_file;
+	int r;
 
-	// LAB 5: Your code here.
-	panic("serve_write not implemented");
+	if((r = openfile_lookup(envid, req->req_fileid, &open_file)) < 0)
+		return r;
+	if((r = file_write(open_file->o_file, req->req_buf, req->req_n, open_file->o_fd->fd_offset)) < 0)
+		return r;
+	
+	open_file->o_fd->fd_offset += r;
+	return r;
 }
 
 // Stat ipc->stat.req_fileid.  Return the file's struct Stat to the