From: millert <millert@openbsd.org>
Date: Tue, 11 Feb 1997 06:59:25 +0000 (+0000)
Subject: Add fs_id support and random inode generation numbers for ffs.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=f4d7a804387374b12e63175fadcb637a8a4dca84;p=openbsd

Add fs_id support and random inode generation numbers for ffs.
---

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 41ea7f092dc..1e6bd4b56a0 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -263,6 +263,8 @@ getnewfsid(mp, mtype)
 
 /*
  * Make a 'unique' number from a mount type name.
+ * Note that this is no longer used for ffs which
+ * now has an on-disk filesystem id.
  */
 long
 makefstype(type)
diff --git a/sys/ufs/ffs/ffs_alloc.c b/sys/ufs/ffs/ffs_alloc.c
index 666560caf32..cd81395a3e3 100644
--- a/sys/ufs/ffs/ffs_alloc.c
+++ b/sys/ufs/ffs/ffs_alloc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ffs_alloc.c,v 1.4 1996/05/22 11:47:17 deraadt Exp $	*/
+/*	$OpenBSD: ffs_alloc.c,v 1.5 1997/02/11 06:59:27 millert Exp $	*/
 /*	$NetBSD: ffs_alloc.c,v 1.11 1996/05/11 18:27:09 mycroft Exp $	*/
 
 /*
@@ -47,6 +47,8 @@
 
 #include <vm/vm.h>
 
+#include <dev/rndvar.h>
+
 #include <ufs/ufs/quota.h>
 #include <ufs/ufs/inode.h>
 #include <ufs/ufs/ufs_extern.h>
@@ -563,10 +565,13 @@ ffs_valloc(v)
 	ip->i_flags = 0;
 	/*
 	 * Set up a new generation number for this inode.
+	 * XXX - just increment for now, this is wrong! (millert)
+	 *       Need a way to preserve randomization.
 	 */
-	if (++nextgennumber < (u_long)time.tv_sec)
-		nextgennumber = time.tv_sec;
-	ip->i_gen = nextgennumber;
+	if (ip->i_gen == 0 || ++(ip->i_gen) == 0)
+		ip->i_gen = arc4random();
+	if (ip->i_gen == 0 || ip->i_gen == -1)
+		ip->i_gen = 1;				/* shouldn't happen */
 	return (0);
 noinodes:
 	ffs_fserr(fs, ap->a_cred->cr_uid, "out of inodes");
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index ee4c214d7b4..a891ede9d9a 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ffs_vfsops.c,v 1.6 1996/06/27 06:42:06 downsj Exp $	*/
+/*	$OpenBSD: ffs_vfsops.c,v 1.7 1997/02/11 06:59:28 millert Exp $	*/
 /*	$NetBSD: ffs_vfsops.c,v 1.19 1996/02/09 22:22:26 christos Exp $	*/
 
 /*
@@ -52,6 +52,8 @@
 #include <sys/errno.h>
 #include <sys/malloc.h>
 
+#include <dev/rndvar.h>
+
 #include <miscfs/specfs/specdev.h>
 
 #include <ufs/ufs/quota.h>
@@ -522,7 +524,11 @@ ffs_mountfs(devvp, mp, p)
 	}
 	mp->mnt_data = (qaddr_t)ump;
 	mp->mnt_stat.f_fsid.val[0] = (long)dev;
-	mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_FFS);
+	/* Use on-disk fsid if it exists, else fake it */
+	if (fs->fs_id[0] != 0 && fs->fs_id[1] != 0)
+		mp->mnt_stat.f_fsid.val[1] = fs->fs_id[1];
+	else
+		mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_FFS);
 	mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
 	mp->mnt_flag |= MNT_LOCAL;
 	ump->um_mountp = mp;
@@ -858,9 +864,9 @@ ffs_vget(mp, ino, vpp)
 	 * already have one. This should only happen on old filesystems.
 	 */
 	if (ip->i_gen == 0) {
-		if (++nextgennumber < (u_long)time.tv_sec)
-			nextgennumber = time.tv_sec;
-		ip->i_gen = nextgennumber;
+		ip->i_gen = arc4random();
+		if (ip->i_gen == 0 || ip->i_gen == -1)
+			ip->i_gen = 1;			/* shouldn't happen */
 		if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0)
 			ip->i_flag |= IN_MODIFIED;
 	}
diff --git a/sys/ufs/ffs/fs.h b/sys/ufs/ffs/fs.h
index 478db6a5be7..ce4f34bef21 100644
--- a/sys/ufs/ffs/fs.h
+++ b/sys/ufs/ffs/fs.h
@@ -198,8 +198,8 @@ struct fs {
 	int32_t	 fs_npsect;		/* # sectors/track including spares */
 	int32_t	 fs_interleave;		/* hardware sector interleave */
 	int32_t	 fs_trackskew;		/* sector 0 skew, per track */
-	int32_t	 fs_headswitch;		/* head switch time, usec */
-	int32_t	 fs_trkseek;		/* track-to-track seek, usec */
+/* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
+	int32_t  fs_id[2];		/* unique filesystem id */
 /* sizes determined by number of cylinder groups and their sizes */
 	daddr_t  fs_csaddr;		/* blk addr of cyl grp summary area */
 	int32_t	 fs_cssize;		/* size of cyl grp summary area */