protect the disk statistics with a mutex.

ok tedu@ kettenis@

3 files changed, 17 insertions, 5 deletions

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index c9b12d50fab..a855b835c6a 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sysctl.c,v 1.158 2007/10/10 15:53:53 art Exp $	*/
+/*	$OpenBSD: kern_sysctl.c,v 1.159 2007/12/23 01:59:58 dlg Exp $	*/
 /*	$NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $	*/
 
 /*-
@@ -1587,6 +1587,7 @@ sysctl_diskinit(int update, struct proc *p)
 			sdk = diskstats + i;
 			strlcpy(sdk->ds_name, dk->dk_name,
 			    sizeof(sdk->ds_name));
+			mtx_enter(&dk->dk_mtx);
 			sdk->ds_busy = dk->dk_busy;
 			sdk->ds_rxfer = dk->dk_rxfer;
 			sdk->ds_wxfer = dk->dk_wxfer;
@@ -1596,6 +1597,7 @@ sysctl_diskinit(int update, struct proc *p)
 			sdk->ds_attachtime = dk->dk_attachtime;
 			sdk->ds_timestamp = dk->dk_timestamp;
 			sdk->ds_time = dk->dk_time;
+			mtx_leave(&dk->dk_mtx);
 		}
 
 		/* Eliminate trailing comma */
@@ -1609,6 +1611,7 @@ sysctl_diskinit(int update, struct proc *p)
 			sdk = diskstats + i;
 			strlcpy(sdk->ds_name, dk->dk_name,
 			    sizeof(sdk->ds_name));
+			mtx_enter(&dk->dk_mtx);
 			sdk->ds_busy = dk->dk_busy;
 			sdk->ds_rxfer = dk->dk_rxfer;
 			sdk->ds_wxfer = dk->dk_wxfer;
@@ -1618,6 +1621,7 @@ sysctl_diskinit(int update, struct proc *p)
 			sdk->ds_attachtime = dk->dk_attachtime;
 			sdk->ds_timestamp = dk->dk_timestamp;
 			sdk->ds_time = dk->dk_time;
+			mtx_leave(&dk->dk_mtx);
 		}
 	}
 	rw_exit_write(&sysctl_disklock);
diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index 2bf6f11b7e0..a07904647e4 100644
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_disk.c,v 1.67 2007/12/16 20:57:17 otto Exp $	*/
+/*	$OpenBSD: subr_disk.c,v 1.68 2007/12/23 01:59:58 dlg Exp $	*/
 /*	$NetBSD: subr_disk.c,v 1.17 1996/03/16 23:17:08 christos Exp $	*/
 
 /*
@@ -712,6 +712,7 @@ int
 disk_construct(struct disk *diskp, char *lockname)
 {
 	rw_init(&diskp->dk_lock, lockname);
+	mtx_init(&diskp->dk_mtx, IPL_BIO);
 	
 	diskp->dk_flags |= DKF_CONSTRUCTED;
 	    
@@ -784,9 +785,10 @@ disk_busy(struct disk *diskp)
 	 * XXX We'd like to use something as accurate as microtime(),
 	 * but that doesn't depend on the system TOD clock.
 	 */
-	if (diskp->dk_busy++ == 0) {
+	mtx_enter(&diskp->dk_mtx);
+	if (diskp->dk_busy++ == 0)
 		microuptime(&diskp->dk_timestamp);
-	}
+	mtx_leave(&diskp->dk_mtx);
 }
 
 /*
@@ -798,6 +800,8 @@ disk_unbusy(struct disk *diskp, long bcount, int read)
 {
 	struct timeval dv_time, diff_time;
 
+	mtx_enter(&diskp->dk_mtx);
+
 	if (diskp->dk_busy-- == 0)
 		printf("disk_unbusy: %s: dk_busy < 0\n", diskp->dk_name);
 
@@ -818,6 +822,8 @@ disk_unbusy(struct disk *diskp, long bcount, int read)
 	} else
 		diskp->dk_seek++;
 
+	mtx_leave(&diskp->dk_mtx);
+
 	add_disk_randomness(bcount ^ diff_time.tv_usec);
 }
 
diff --git a/sys/sys/disk.h b/sys/sys/disk.h
index ccab35d1010..e045bb08f5f 100644
--- a/sys/sys/disk.h
+++ b/sys/sys/disk.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: disk.h,v 1.17 2007/06/20 18:15:47 deraadt Exp $	*/
+/*	$OpenBSD: disk.h,v 1.18 2007/12/23 01:59:58 dlg Exp $	*/
 /*	$NetBSD: disk.h,v 1.11 1996/04/28 20:22:50 thorpej Exp $	*/
 
 /*
@@ -51,6 +51,7 @@
 #include <sys/time.h>
 #include <sys/queue.h>
 #include <sys/rwlock.h>
+#include <sys/mutex.h>
 
 struct buf;
 struct disklabel;
@@ -73,6 +74,7 @@ struct diskstats {
 struct disk {
 	TAILQ_ENTRY(disk) dk_link;	/* link in global disklist */
 	struct rwlock	dk_lock;	/* disk lock */
+	struct mutex	dk_mtx;		/* busy/unbusy mtx */
 	char		*dk_name;	/* disk name */
 	int		dk_flags;	/* disk flags */
 #define DKF_CONSTRUCTED  0x0001