1 files changed, 102 insertions, 0 deletions
diff --git a/linux/fs/super.c b/linux/fs/super.c
new file mode 100644
index 0000000..d832289
--- /dev/null
+++ b/linux/fs/super.c
@@ -0,0 +1,102 @@
+/*
+ * super.c contains code to handle the super-block tables.
+ */
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+
+/* set_bit uses setb, as gas doesn't recognize setc */
+#define set_bit(bitnr,addr) ({ \
+register int __res __asm__("ax"); \
+__asm__("bt %2,%3;setb %%al":"=a" (__res):"a" (0),"r" (bitnr),"m" (*(addr))); \
+__res; })
+
+struct super_block super_block[NR_SUPER];
+
+struct super_block * do_mount(int dev)
+{
+	struct super_block * p;
+	struct buffer_head * bh;
+	int i,block;
+
+	for(p = &super_block[0] ; p < &super_block[NR_SUPER] ; p++ )
+		if (!(p->s_dev))
+			break;
+	p->s_dev = -1;		/* mark it in use */
+	if (p >= &super_block[NR_SUPER])
+		return NULL;
+	if (!(bh = bread(dev,1)))
+		return NULL;
+	*p = *((struct super_block *) bh->b_data);
+	brelse(bh);
+	if (p->s_magic != SUPER_MAGIC) {
+		p->s_dev = 0;
+		return NULL;
+	}
+	for (i=0;i<I_MAP_SLOTS;i++)
+		p->s_imap[i] = NULL;
+	for (i=0;i<Z_MAP_SLOTS;i++)
+		p->s_zmap[i] = NULL;
+	block=2;
+	for (i=0 ; i < p->s_imap_blocks ; i++)
+		if (p->s_imap[i]=bread(dev,block))
+			block++;
+		else
+			break;
+	for (i=0 ; i < p->s_zmap_blocks ; i++)
+		if (p->s_zmap[i]=bread(dev,block))
+			block++;
+		else
+			break;
+	if (block != 2+p->s_imap_blocks+p->s_zmap_blocks) {
+		for(i=0;i<I_MAP_SLOTS;i++)
+			brelse(p->s_imap[i]);
+		for(i=0;i<Z_MAP_SLOTS;i++)
+			brelse(p->s_zmap[i]);
+		p->s_dev=0;
+		return NULL;
+	}
+	p->s_imap[0]->b_data[0] |= 1;
+	p->s_zmap[0]->b_data[0] |= 1;
+	p->s_dev = dev;
+	p->s_isup = NULL;
+	p->s_imount = NULL;
+	p->s_time = 0;
+	p->s_rd_only = 0;
+	p->s_dirt = 0;
+	return p;
+}
+
+void mount_root(void)
+{
+	int i,free;
+	struct super_block * p;
+	struct m_inode * mi;
+
+	if (32 != sizeof (struct d_inode))
+		panic("bad i-node size");
+	for(i=0;i<NR_FILE;i++)
+		file_table[i].f_count=0;
+	for(p = &super_block[0] ; p < &super_block[NR_SUPER] ; p++)
+		p->s_dev = 0;
+	if (!(p=do_mount(ROOT_DEV)))
+		panic("Unable to mount root");
+	if (!(mi=iget(ROOT_DEV,1)))
+		panic("Unable to read root i-node");
+	mi->i_count += 3 ;	/* NOTE! it is logically used 4 times, not 1 */
+	p->s_isup = p->s_imount = mi;
+	current->pwd = mi;
+	current->root = mi;
+	free=0;
+	i=p->s_nzones;
+	while (-- i >= 0)
+		if (!set_bit(i&8191,p->s_zmap[i>>13]->b_data))
+			free++;
+	printk("%d/%d free blocks\n\r",free,p->s_nzones);
+	free=0;
+	i=p->s_ninodes+1;
+	while (-- i >= 0)
+		if (!set_bit(i&8191,p->s_imap[i>>13]->b_data))
+			free++;
+	printk("%d/%d free inodes\n\r",free,p->s_ninodes);
+}