feat: 添加 Lab 5 练习 1-3 代码

fs/bc.c

@@ -48,7 +48,12 @@ bc_pgfault(struct UTrapframe *utf)
 	// the disk.
 	//
 	// LAB 5: you code here:
-
+	addr = ROUNDDOWN(addr, PGSIZE);
+	if ((r = sys_page_alloc(0, addr, PTE_P | PTE_U | PTE_W)) < 0)
+		panic("in bc_pgfault, sys_page_alloc: %e", r);
+
+	if ((r = ide_read(blockno * BLKSIZE / SECTSIZE, addr, BLKSIZE / SECTSIZE)) < 0)
+		panic("in bc_pgfault, ide_read: %e", r);
 	// Clear the dirty bit for the disk block page since we just read the
 	// block from disk
 	if ((r = sys_page_map(0, addr, 0, addr, uvpt[PGNUM(addr)] & PTE_SYSCALL)) < 0)
@@ -77,7 +82,13 @@ flush_block(void *addr)
 		panic("flush_block of bad va %08x", addr);
 
 	// LAB 5: Your code here.
-	panic("flush_block not implemented");
+	int r;
+	addr = ROUNDDOWN(addr, PGSIZE);
+	if (!va_is_mapped(addr) || !va_is_dirty(addr)) return;
+	if ((r = ide_write(blockno * BLKSIZE / SECTSIZE, addr, BLKSIZE / SECTSIZE)) < 0)
+		panic("in flush_block, ide_write: %e", r);
+	if ((r = sys_page_map(0, addr, 0, addr, uvpt[PGNUM(addr)] & PTE_SYSCALL)) < 0)
+		panic("in flush_block, sys_page_map: %e", r);
 }
 
 // Test that the block cache works, by smashing the superblock and

fs/fs.c

@@ -62,7 +62,13 @@ alloc_block(void)
 	// super->s_nblocks blocks in the disk altogether.
 
 	// LAB 5: Your code here.
-	panic("alloc_block not implemented");
+	for (int i = 3; i < super->s_nblocks; i++) {
+		if (block_is_free(i)) {
+			bitmap[i/32] &= ~(1<<(i%32));
+			return i;
+		}
+	}
+
 	return -E_NO_DISK;
 }
 

kern/env.c

@@ -404,6 +404,9 @@ env_create(uint8_t *binary, enum EnvType type)
 
 	// If this is the file server (type == ENV_TYPE_FS) give it I/O privileges.
 	// LAB 5: Your code here.
+	if (type == ENV_TYPE_FS) {
+		env->env_tf.tf_eflags |= FL_IOPL_MASK;
+	}
 }
 
 //