Keep track of the mount point associated with a special device

to enable the collection of counts of synchronous and asynchronous
reads and writes for its associated filesystem. The counts are
displayed using `mount -v'.

Ensure that buffers used for paging indicate the vnode from
which they are operating so that counts of paging I/O operations
from the filesystem are collected.

This checkin only adds the setting of the mount point for the
UFS/FFS filesystem, but it would be trivial to add the setting
and clearing of the mount point at filesystem mount/unmount
time for other filesystems too.

Reviewed by: kib

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/vm/vnode_pager.c b/sys/vm/vnode_pager.c
index c5b6c17..c8c57e1 100644
--- a/sys/vm/vnode_pager.c
+++ b/sys/vm/vnode_pager.c
@@ -543,6 +543,7 @@ vnode_pager_input_smlfs(object, m)
 			bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
 			bp->b_blkno = fileaddr;
 			pbgetbo(bo, bp);
+			bp->b_vp = vp;
 			bp->b_bcount = bsize;
 			bp->b_bufsize = bsize;
 			bp->b_runningbufspace = bp->b_bufsize;
@@ -560,6 +561,7 @@ vnode_pager_input_smlfs(object, m)
 			/*
 			 * free the buffer header back to the swap buffer pool
 			 */
+			bp->b_vp = NULL;
 			pbrelbo(bp);
 			relpbuf(bp, &vnode_pbuf_freecnt);
 			if (error)
@@ -918,6 +920,7 @@ vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
 	bp->b_wcred = crhold(curthread->td_ucred);
 	bp->b_blkno = firstaddr;
 	pbgetbo(bo, bp);
+	bp->b_vp = vp;
 	bp->b_bcount = size;
 	bp->b_bufsize = size;
 	bp->b_runningbufspace = bp->b_bufsize;
@@ -944,6 +947,7 @@ vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
 	/*
 	 * free the buffer header back to the swap buffer pool
 	 */
+	bp->b_vp = NULL;
 	pbrelbo(bp);
 	relpbuf(bp, &vnode_pbuf_freecnt);