Sync timestamp changes for inodes of special files to disk as late

as possible (when the inode is reclaimed).  Temporarily only do
this if option UFS_LAZYMOD configured and softupdates aren't enabled.
UFS_LAZYMOD is intentionally left out of /sys/conf/options.

This is mainly to avoid almost useless disk i/o on battery powered
machines.  It's silly to write to disk (on the next sync or when the
inode becomes inactive) just because someone hit a key or something
wrote to the screen or /dev/null.

PR:		5577
Previous version reviewed by:	phk

8 files changed, 44 insertions, 29 deletions

diff --git a/sys/gnu/ext2fs/ext2_inode.c b/sys/gnu/ext2fs/ext2_inode.c
index a094ad2..ae37b2c8 100644
--- a/sys/gnu/ext2fs/ext2_inode.c
+++ b/sys/gnu/ext2fs/ext2_inode.c
@@ -72,12 +72,12 @@ ext2_init(struct vfsconf *vfsp)
 
 /*
  * Update the access, modified, and inode change times as specified by the
- * IACCESS, IUPDATE, and ICHANGE flags respectively. The IMODIFIED flag is
- * used to specify that the inode needs to be updated but that the times have
- * already been set. The access and modified times are taken from the second
- * and third parameters; the inode change time is always taken from the current
- * time. If waitfor is set, then wait for the disk write of the inode to
- * complete.
+ * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
+ * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
+ * the timestamp update).  The IN_LAZYMOD flag is set to force a write
+ * later if not now.  If we write now, then clear both IN_MODIFIED and
+ * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
+ * set, then wait for the write to complete.
  */
 int
 ext2_update(vp, access, modify, waitfor)
@@ -95,7 +95,7 @@ ext2_update(vp, access, modify, waitfor)
 	ip = VTOI(vp);
 	if ((ip->i_flag & IN_MODIFIED) == 0)
 		return (0);
-	ip->i_flag &= ~IN_MODIFIED;
+	ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
 		return (0);
 	fs = ip->i_e2fs;
diff --git a/sys/gnu/ext2fs/inode.h b/sys/gnu/ext2fs/inode.h
index c787e1e..76b7b5e 100644
--- a/sys/gnu/ext2fs/inode.h
+++ b/sys/gnu/ext2fs/inode.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)inode.h	8.9 (Berkeley) 5/14/95
- * $Id: inode.h,v 1.21 1998/03/08 09:59:21 julian Exp $
+ * $Id: inode.h,v 1.22 1998/03/26 20:53:58 phk Exp $
  */
 
 #ifndef _UFS_UFS_INODE_H_
@@ -127,6 +127,7 @@ struct inode {
 #define	IN_SHLOCK	0x0020		/* File has shared lock. */
 #define	IN_EXLOCK	0x0040		/* File has exclusive lock. */
 #define	IN_HASHED	0x0080		/* Inode is on hash list */
+#define	IN_LAZYMOD	0x0100		/* Modified, but don't write yet. */
 
 #ifdef KERNEL
 /*
diff --git a/sys/gnu/fs/ext2fs/ext2_inode.c b/sys/gnu/fs/ext2fs/ext2_inode.c
index a094ad2..ae37b2c8 100644
--- a/sys/gnu/fs/ext2fs/ext2_inode.c
+++ b/sys/gnu/fs/ext2fs/ext2_inode.c
@@ -72,12 +72,12 @@ ext2_init(struct vfsconf *vfsp)
 
 /*
  * Update the access, modified, and inode change times as specified by the
- * IACCESS, IUPDATE, and ICHANGE flags respectively. The IMODIFIED flag is
- * used to specify that the inode needs to be updated but that the times have
- * already been set. The access and modified times are taken from the second
- * and third parameters; the inode change time is always taken from the current
- * time. If waitfor is set, then wait for the disk write of the inode to
- * complete.
+ * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
+ * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
+ * the timestamp update).  The IN_LAZYMOD flag is set to force a write
+ * later if not now.  If we write now, then clear both IN_MODIFIED and
+ * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
+ * set, then wait for the write to complete.
  */
 int
 ext2_update(vp, access, modify, waitfor)
@@ -95,7 +95,7 @@ ext2_update(vp, access, modify, waitfor)
 	ip = VTOI(vp);
 	if ((ip->i_flag & IN_MODIFIED) == 0)
 		return (0);
-	ip->i_flag &= ~IN_MODIFIED;
+	ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
 		return (0);
 	fs = ip->i_e2fs;
diff --git a/sys/gnu/fs/ext2fs/inode.h b/sys/gnu/fs/ext2fs/inode.h
index c787e1e..76b7b5e 100644
--- a/sys/gnu/fs/ext2fs/inode.h
+++ b/sys/gnu/fs/ext2fs/inode.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)inode.h	8.9 (Berkeley) 5/14/95
- * $Id: inode.h,v 1.21 1998/03/08 09:59:21 julian Exp $
+ * $Id: inode.h,v 1.22 1998/03/26 20:53:58 phk Exp $
  */
 
 #ifndef _UFS_UFS_INODE_H_
@@ -127,6 +127,7 @@ struct inode {
 #define	IN_SHLOCK	0x0020		/* File has shared lock. */
 #define	IN_EXLOCK	0x0040		/* File has exclusive lock. */
 #define	IN_HASHED	0x0080		/* Inode is on hash list */
+#define	IN_LAZYMOD	0x0100		/* Modified, but don't write yet. */
 
 #ifdef KERNEL
 /*
diff --git a/sys/ufs/ffs/ffs_inode.c b/sys/ufs/ffs/ffs_inode.c
index 89254a2..df06020 100644
--- a/sys/ufs/ffs/ffs_inode.c
+++ b/sys/ufs/ffs/ffs_inode.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
- * $Id: ffs_inode.c,v 1.43 1998/06/14 19:31:28 julian Exp $
+ * $Id: ffs_inode.c,v 1.44 1998/07/03 18:46:47 bde Exp $
  */
 
 #include "opt_quota.h"
@@ -62,12 +62,12 @@ static int ffs_indirtrunc __P((struct inode *, ufs_daddr_t, ufs_daddr_t,
 
 /*
  * Update the access, modified, and inode change times as specified by the
- * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively. The IN_MODIFIED
- * flag is used to specify that the inode needs to be updated even if none
- * of the times needs to be updated. The access and modified times are taken
- * from the second and third parameters; the inode change time is always
- * taken from the current time. If waitfor is set, then wait for the disk
- * write of the inode to complete.
+ * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
+ * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
+ * the timestamp update).  The IN_LAZYMOD flag is set to force a write
+ * later if not now.  If we write now, then clear both IN_MODIFIED and
+ * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
+ * set, then wait for the write to complete.
  */
 int
 ffs_update(vp, access, modify, waitfor)
@@ -85,7 +85,7 @@ ffs_update(vp, access, modify, waitfor)
 	ip = VTOI(vp);
 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor != MNT_WAIT)
 		return (0);
-	ip->i_flag &= ~IN_MODIFIED;
+	ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
 		return (0);
 	fs = ip->i_fs;
diff --git a/sys/ufs/ufs/inode.h b/sys/ufs/ufs/inode.h
index c787e1e..76b7b5e 100644
--- a/sys/ufs/ufs/inode.h
+++ b/sys/ufs/ufs/inode.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)inode.h	8.9 (Berkeley) 5/14/95
- * $Id: inode.h,v 1.21 1998/03/08 09:59:21 julian Exp $
+ * $Id: inode.h,v 1.22 1998/03/26 20:53:58 phk Exp $
  */
 
 #ifndef _UFS_UFS_INODE_H_
@@ -127,6 +127,7 @@ struct inode {
 #define	IN_SHLOCK	0x0020		/* File has shared lock. */
 #define	IN_EXLOCK	0x0040		/* File has exclusive lock. */
 #define	IN_HASHED	0x0080		/* Inode is on hash list */
+#define	IN_LAZYMOD	0x0100		/* Modified, but don't write yet. */
 
 #ifdef KERNEL
 /*
diff --git a/sys/ufs/ufs/ufs_inode.c b/sys/ufs/ufs/ufs_inode.c
index f63c08a..be4d2bb 100644
--- a/sys/ufs/ufs/ufs_inode.c
+++ b/sys/ufs/ufs/ufs_inode.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ufs_inode.c	8.9 (Berkeley) 5/14/95
- * $Id: ufs_inode.c,v 1.21 1997/12/02 11:43:45 bde Exp $
+ * $Id: ufs_inode.c,v 1.22 1998/03/30 09:56:16 phk Exp $
  */
 
 #include "opt_quota.h"
@@ -116,16 +116,22 @@ ufs_reclaim(ap)
 {
 	register struct inode *ip;
 	register struct vnode *vp = ap->a_vp;
+	struct timeval tv;
 #ifdef QUOTA
 	int i;
 #endif
 
 	if (prtactive && vp->v_usecount != 0)
 		vprint("ufs_reclaim: pushing active", vp);
+	ip = VTOI(vp);
+	if (ip->i_flag & IN_LAZYMOD) {
+		ip->i_flag |= IN_MODIFIED;
+		getmicrotime(&tv);
+		UFS_UPDATE(vp, &tv, &tv, 0);
+	}
 	/*
 	 * Remove the inode from its hash chain.
 	 */
-	ip = VTOI(vp);
 	ufs_ihashrem(ip);
 	/*
 	 * Purge old data structures associated with the inode.
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index bbf701c..2a64e25 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ufs_vnops.c	8.27 (Berkeley) 5/27/95
- * $Id: ufs_vnops.c,v 1.88 1998/06/08 23:55:33 julian Exp $
+ * $Id: ufs_vnops.c,v 1.91 1998/07/03 18:46:49 bde Exp $
  */
 
 #include "opt_quota.h"
@@ -145,7 +145,13 @@ ufs_itimes(vp)
 		return;
 	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
 		tv_sec = time_second;
-		ip->i_flag |= IN_MODIFIED;
+#ifdef UFS_LAZYMOD
+		if ((vp->v_type == VBLK || vp->v_type == VCHR) &&
+		    !DOINGSOFTDEP(vp))
+			ip->i_flag |= IN_LAZYMOD;
+		else
+#endif
+			ip->i_flag |= IN_MODIFIED;
 		if (ip->i_flag & IN_ACCESS)
 			ip->i_atime = tv_sec;
 		if (ip->i_flag & IN_UPDATE) {