Add original unix v6

2018-01-27 22:35:41 +09:00
commit 2c7099ee50
664 changed files with 106254 additions and 0 deletions
@@ -0,0 +1,207 @@
+#
+/*
+ */
+
+#include "../param.h"
+#include "../conf.h"
+#include "../inode.h"
+#include "../user.h"
+#include "../buf.h"
+#include "../systm.h"
+
+/*
+ * Bmap defines the structure of file system storage
+ * by returning the physical block number on a device given the
+ * inode and the logical block number in a file.
+ * When convenient, it also leaves the physical
+ * block number of the next block of the file in rablock
+ * for use in read-ahead.
+ */
+bmap(ip, bn)
+struct inode *ip;
+int bn;
+{
+	register *bp, *bap, nb;
+	int *nbp, d, i;
+
+	d = ip->i_dev;
+	if(bn & ~077777) {
+		u.u_error = EFBIG;
+		return(0);
+	}
+
+	if((ip->i_mode&ILARG) == 0) {
+
+		/*
+		 * small file algorithm
+		 */
+
+		if((bn & ~7) != 0) {
+
+			/*
+			 * convert small to large
+			 */
+
+			if ((bp = alloc(d)) == NULL)
+				return(NULL);
+			bap = bp->b_addr;
+			for(i=0; i<8; i++) {
+				*bap++ = ip->i_addr[i];
+				ip->i_addr[i] = 0;
+			}
+			ip->i_addr[0] = bp->b_blkno;
+			bdwrite(bp);
+			ip->i_mode =| ILARG;
+			goto large;
+		}
+		nb = ip->i_addr[bn];
+		if(nb == 0 && (bp = alloc(d)) != NULL) {
+			bdwrite(bp);
+			nb = bp->b_blkno;
+			ip->i_addr[bn] = nb;
+			ip->i_flag =| IUPD;
+		}
+		rablock = 0;
+		if (bn<7)
+			rablock = ip->i_addr[bn+1];
+		return(nb);
+	}
+
+	/*
+	 * large file algorithm
+	 */
+
+    large:
+	i = bn>>8;
+	if(bn & 0174000)
+		i = 7;
+	if((nb=ip->i_addr[i]) == 0) {
+		ip->i_flag =| IUPD;
+		if ((bp = alloc(d)) == NULL)
+			return(NULL);
+		ip->i_addr[i] = bp->b_blkno;
+	} else
+		bp = bread(d, nb);
+	bap = bp->b_addr;
+
+	/*
+	 * "huge" fetch of double indirect block
+	 */
+
+	if(i == 7) {
+		i = ((bn>>8) & 0377) - 7;
+		if((nb=bap[i]) == 0) {
+			if((nbp = alloc(d)) == NULL) {
+				brelse(bp);
+				return(NULL);
+			}
+			bap[i] = nbp->b_blkno;
+			bdwrite(bp);
+		} else {
+			brelse(bp);
+			nbp = bread(d, nb);
+		}
+		bp = nbp;
+		bap = bp->b_addr;
+	}
+
+	/*
+	 * normal indirect fetch
+	 */
+
+	i = bn & 0377;
+	if((nb=bap[i]) == 0 && (nbp = alloc(d)) != NULL) {
+		nb = nbp->b_blkno;
+		bap[i] = nb;
+		bdwrite(nbp);
+		bdwrite(bp);
+	} else
+		brelse(bp);
+	rablock = 0;
+	if(i < 255)
+		rablock = bap[i+1];
+	return(nb);
+}
+
+/*
+ * Pass back  c  to the user at his location u_base;
+ * update u_base, u_count, and u_offset.  Return -1
+ * on the last character of the user's read.
+ * u_base is in the user address space unless u_segflg is set.
+ */
+passc(c)
+char c;
+{
+
+	if(u.u_segflg)
+		*u.u_base = c; else
+		if(subyte(u.u_base, c) < 0) {
+			u.u_error = EFAULT;
+			return(-1);
+		}
+	u.u_count--;
+	if(++u.u_offset[1] == 0)
+		u.u_offset[0]++;
+	u.u_base++;
+	return(u.u_count == 0? -1: 0);
+}
+
+/*
+ * Pick up and return the next character from the user's
+ * write call at location u_base;
+ * update u_base, u_count, and u_offset.  Return -1
+ * when u_count is exhausted.  u_base is in the user's
+ * address space unless u_segflg is set.
+ */
+cpass()
+{
+	register c;
+
+	if(u.u_count == 0)
+		return(-1);
+	if(u.u_segflg)
+		c = *u.u_base; else
+		if((c=fubyte(u.u_base)) < 0) {
+			u.u_error = EFAULT;
+			return(-1);
+		}
+	u.u_count--;
+	if(++u.u_offset[1] == 0)
+		u.u_offset[0]++;
+	u.u_base++;
+	return(c&0377);
+}
+
+/*
+ * Routine which sets a user error; placed in
+ * illegal entries in the bdevsw and cdevsw tables.
+ */
+nodev()
+{
+
+	u.u_error = ENODEV;
+}
+
+/*
+ * Null routine; placed in insignificant entries
+ * in the bdevsw and cdevsw tables.
+ */
+nulldev()
+{
+}
+
+/*
+ * copy count words from from to to.
+ */
+bcopy(from, to, count)
+int *from, *to;
+{
+	register *a, *b, c;
+
+	a = from;
+	b = to;
+	c = count;
+	do
+		*b++ = *a++;
+	while(--c);
+}