From 9440653d07a9ab9b15dea77ce2cf508cfb0adf5e Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@FreeBSD.org>
Date: Wed, 6 Dec 2000 20:55:09 +0000
Subject: [PATCH] Add necessary bwillwrite() in writev() entry point.

Deal with excessive dirty buffers when msync() syncs non-contiguous
dirty buffers by checking for the case in UFS *before* checking for
clusterability.
---
 sys/kern/sys_generic.c      | 1 +
 sys/ufs/ufs/ufs_readwrite.c | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 8452cc0f3a2f..bce9231da92a 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -496,6 +496,7 @@ writev(p, uap)
 	}
 #endif
 	cnt = auio.uio_resid;
+	bwillwrite();
 	if ((error = fo_write(fp, &auio, fp->f_cred, 0, p))) {
 		if (auio.uio_resid != cnt && (error == ERESTART ||
 		    error == EINTR || error == EWOULDBLOCK))
diff --git a/sys/ufs/ufs/ufs_readwrite.c b/sys/ufs/ufs/ufs_readwrite.c
index 785219c8aded..4830120c6213 100644
--- a/sys/ufs/ufs/ufs_readwrite.c
+++ b/sys/ufs/ufs/ufs_readwrite.c
@@ -495,6 +495,9 @@ WRITE(ap)
 
 		if (ioflag & IO_SYNC) {
 			(void)bwrite(bp);
+		} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
+			bp->b_flags |= B_CLUSTEROK;
+			bawrite(bp);
 		} else if (xfersize + blkoffset == fs->fs_bsize) {
 			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
 				bp->b_flags |= B_CLUSTEROK;
@@ -502,9 +505,6 @@ WRITE(ap)
 			} else {
 				bawrite(bp);
 			}
-		} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
-			bp->b_flags |= B_CLUSTEROK;
-			bawrite(bp);
 		} else {
 			bp->b_flags |= B_CLUSTEROK;
 			bdwrite(bp);