Add four new RCTL resources - readbps, readiops, writebps and writeiops,

for limiting disk (actually filesystem) IO.

Note that in some cases these limits are not quite precise. It's ok,
as long as it's within some reasonable bounds.

Testing - and review of the code, in particular the VFS and VM parts - is
very welcome.

MFC after:	1 month
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D5080

1 files changed, 28 insertions, 3 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index e272f9d..b7b9641 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -61,6 +61,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/kernel.h>
 #include <sys/kthread.h>
 #include <sys/proc.h>
+#include <sys/racct.h>
 #include <sys/resourcevar.h>
 #include <sys/rwlock.h>
 #include <sys/smp.h>
@@ -1784,8 +1785,16 @@ breada(struct vnode * vp, daddr_t * rablkno, int * rabsize,
 		rabp = getblk(vp, *rablkno, *rabsize, 0, 0, 0);
 
 		if ((rabp->b_flags & B_CACHE) == 0) {
-			if (!TD_IS_IDLETHREAD(curthread))
+			if (!TD_IS_IDLETHREAD(curthread)) {
+#ifdef RACCT
+				if (racct_enable) {
+					PROC_LOCK(curproc);
+					racct_add_buf(curproc, rabp, 0);
+					PROC_UNLOCK(curproc);
+				}
+#endif /* RACCT */
 				curthread->td_ru.ru_inblock++;
+			}
 			rabp->b_flags |= B_ASYNC;
 			rabp->b_flags &= ~B_INVAL;
 			rabp->b_ioflags &= ~BIO_ERROR;
@@ -1829,8 +1838,16 @@ breadn_flags(struct vnode *vp, daddr_t blkno, int size, daddr_t *rablkno,
 
 	/* if not found in cache, do some I/O */
 	if ((bp->b_flags & B_CACHE) == 0) {
-		if (!TD_IS_IDLETHREAD(curthread))
+		if (!TD_IS_IDLETHREAD(curthread)) {
+#ifdef RACCT
+			if (racct_enable) {
+				PROC_LOCK(curproc);
+				racct_add_buf(curproc, bp, 0);
+				PROC_UNLOCK(curproc);
+			}
+#endif /* RACCT */
 			curthread->td_ru.ru_inblock++;
+		}
 		bp->b_iocmd = BIO_READ;
 		bp->b_flags &= ~B_INVAL;
 		bp->b_ioflags &= ~BIO_ERROR;
@@ -1926,8 +1943,16 @@ bufwrite(struct buf *bp)
 	bp->b_runningbufspace = bp->b_bufsize;
 	space = atomic_fetchadd_long(&runningbufspace, bp->b_runningbufspace);
 
-	if (!TD_IS_IDLETHREAD(curthread))
+	if (!TD_IS_IDLETHREAD(curthread)) {
+#ifdef RACCT
+		if (racct_enable) {
+			PROC_LOCK(curproc);
+			racct_add_buf(curproc, bp, 1);
+			PROC_UNLOCK(curproc);
+		}
+#endif /* RACCT */
 		curthread->td_ru.ru_oublock++;
+	}
 	if (oldflags & B_ASYNC)
 		BUF_KERNPROC(bp);
 	bp->b_iooffset = dbtob(bp->b_blkno);