Collect read and write counts for filesystems. This new code

drops the counting in bwrite and puts it all in spec_strategy.
I did some tests and verified that the counts collected for writes
in spec_strategy is identical to the counts that we previously
collected in bwrite. We now also get read counts (async reads
come from requests for read-ahead blocks). Note that you need
to compile a new version of mount to get the read counts printed
out. The old mount binary is completely compatible, the only
reason to install a new mount is to get the read counts printed.

Submitted by:	Craig A Soules <soules+@andrew.cmu.edu>
Reviewed by:	Kirk McKusick <mckusick@mckusick.com>

1 files changed, 0 insertions, 20 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index c3dc70e..dd135cf 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -589,8 +589,6 @@ int
 bwrite(struct buf * bp)
 {
 	int oldflags, s;
-	struct vnode *vp;
-	struct mount *mp;
 
 	if (bp->b_flags & B_INVAL) {
 		brelse(bp);
@@ -618,24 +616,6 @@ bwrite(struct buf * bp)
 		BUF_KERNPROC(bp);
 	VOP_STRATEGY(bp->b_vp, bp);
 
-	/*
-	 * Collect statistics on synchronous and asynchronous writes.
-	 * Writes to block devices are charged to their associated
-	 * filesystem (if any).
-	 */
-	if ((vp = bp->b_vp) != NULL) {
-		if (vn_isdisk(vp))
-			mp = vp->v_specmountpoint;
-		else
-			mp = vp->v_mount;
-		if (mp != NULL) {
-			if ((oldflags & B_ASYNC) == 0)
-				mp->mnt_stat.f_syncwrites++;
-			else
-				mp->mnt_stat.f_asyncwrites++;
-		}
-	}
-
 	if ((oldflags & B_ASYNC) == 0) {
 		int rtval = biowait(bp);
 		brelse(bp);