From: sf <sf@openbsd.org>
Date: Mon, 29 May 2017 14:05:31 +0000 (+0000)
Subject: Add an ioctl to tell storage devices to flush their internal caches
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=805cc48e2b68c21c3fa7691b37d49349beee417a;p=openbsd

Add an ioctl to tell storage devices to flush their internal caches

Currently implemented for wd and sd.
Initially ported from netbsd by pedro@

ok deraadt@
---

diff --git a/sys/dev/ata/wd.c b/sys/dev/ata/wd.c
index cd168223672..a6dc2c5fcb9 100644
--- a/sys/dev/ata/wd.c
+++ b/sys/dev/ata/wd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wd.c,v 1.121 2017/05/04 22:47:27 deraadt Exp $ */
+/*	$OpenBSD: wd.c,v 1.122 2017/05/29 14:05:31 sf Exp $ */
 /*	$NetBSD: wd.c,v 1.193 1999/02/28 17:15:27 explorer Exp $ */
 
 /*
@@ -26,7 +26,7 @@
  */
 
 /*-
- * Copyright (c) 1998 The NetBSD Foundation, Inc.
+ * Copyright (c) 1998, 2003, 2004 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
@@ -138,7 +138,7 @@ void  wdstart(void *);
 void  __wdstart(struct wd_softc*, struct buf *);
 void  wdrestart(void *);
 int   wd_get_params(struct wd_softc *, u_int8_t, struct ataparams *);
-void  wd_flushcache(struct wd_softc *, int);
+int   wd_flushcache(struct wd_softc *, int);
 void  wd_standby(struct wd_softc *, int);
 
 /* XXX: these should go elsewhere */
@@ -848,6 +848,14 @@ wdioctl(dev_t dev, u_long xfer, caddr_t addr, int flag, struct proc *p)
 		}
 #endif
 
+	case DIOCCACHESYNC:
+		if ((flag & FWRITE) == 0) {
+			error = EBADF;
+			goto exit;
+		}
+		error = wd_flushcache(wd, AT_WAIT);
+		goto exit;
+
 	default:
 		error = wdc_ioctl(wd->drvp, xfer, addr, flag, p);
 		goto exit;
@@ -1067,13 +1075,13 @@ wd_get_params(struct wd_softc *wd, u_int8_t flags, struct ataparams *params)
 	}
 }
 
-void
+int
 wd_flushcache(struct wd_softc *wd, int flags)
 {
 	struct wdc_command wdc_c;
 
 	if (wd->drvp->ata_vers < 4) /* WDCC_FLUSHCACHE is here since ATA-4 */
-		return;
+		return EIO;
 	bzero(&wdc_c, sizeof(struct wdc_command));
 	wdc_c.r_command = (wd->sc_flags & WDF_LBA48 ? WDCC_FLUSHCACHE_EXT :
 	    WDCC_FLUSHCACHE);
@@ -1088,20 +1096,28 @@ wd_flushcache(struct wd_softc *wd, int flags)
 	if (wdc_exec_command(wd->drvp, &wdc_c) != WDC_COMPLETE) {
 		printf("%s: flush cache command didn't complete\n",
 		    wd->sc_dev.dv_xname);
+		return EIO;
 	}
+	if (wdc_c.flags & ERR_NODEV)
+		return ENODEV;
 	if (wdc_c.flags & AT_TIMEOU) {
 		printf("%s: flush cache command timeout\n",
 		    wd->sc_dev.dv_xname);
+		return EIO;
+	}
+	if (wdc_c.flags & AT_ERROR) {
+		if (wdc_c.r_error == WDCE_ABRT) /* command not supported */
+			return ENODEV;
+		printf("%s: flush cache command: error 0x%x\n",
+		    wd->sc_dev.dv_xname, wdc_c.r_error);
+		return EIO;
 	}
 	if (wdc_c.flags & AT_DF) {
 		printf("%s: flush cache command: drive fault\n",
 		    wd->sc_dev.dv_xname);
+		return EIO;
 	}
-	/*
-	 * Ignore error register, it shouldn't report anything else
-	 * than COMMAND ABORTED, which means the device doesn't support
-	 * flush cache
-	 */
+	return 0;
 }
 
 void
diff --git a/sys/scsi/sd.c b/sys/scsi/sd.c
index bb93ca1a1ba..0a26c87581c 100644
--- a/sys/scsi/sd.c
+++ b/sys/scsi/sd.c
@@ -1,8 +1,8 @@
-/*	$OpenBSD: sd.c,v 1.271 2017/05/29 07:47:13 krw Exp $	*/
+/*	$OpenBSD: sd.c,v 1.272 2017/05/29 14:05:31 sf Exp $	*/
 /*	$NetBSD: sd.c,v 1.111 1997/04/02 02:29:41 mycroft Exp $	*/
 
 /*-
- * Copyright (c) 1998 The NetBSD Foundation, Inc.
+ * Copyright (c) 1998, 2003, 2004 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
@@ -96,7 +96,7 @@ int	sd_vpd_block_limits(struct sd_softc *, int);
 int	sd_vpd_thin(struct sd_softc *, int);
 int	sd_thin_params(struct sd_softc *, int);
 int	sd_get_parms(struct sd_softc *, struct disk_parms *, int);
-void	sd_flush(struct sd_softc *, int);
+int	sd_flush(struct sd_softc *, int);
 
 void	viscpy(u_char *, u_char *, int);
 
@@ -989,6 +989,15 @@ sdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 		error = sd_ioctl_cache(sc, cmd, (struct dk_cache *)addr);
 		goto exit;
 
+	case DIOCCACHESYNC:
+		if (!ISSET(flag, FWRITE)) {
+			error = EBADF;
+			goto exit;
+		}
+		if ((sc->flags & SDF_DIRTY) != 0 || *(int *)addr != 0)
+			error = sd_flush(sc, 0);
+		goto exit;
+
 	default:
 		if (part != RAW_PART) {
 			error = ENOTTY;
@@ -1866,19 +1875,20 @@ die:
 	return (SDGP_RESULT_OFFLINE);
 }
 
-void
+int
 sd_flush(struct sd_softc *sc, int flags)
 {
 	struct scsi_link *link;
 	struct scsi_xfer *xs;
 	struct scsi_synchronize_cache *cmd;
+	int error;
 
 	if (sc->flags & SDF_DYING)
-		return;
+		return (ENXIO);
 	link = sc->sc_link;
 
 	if (link->quirks & SDEV_NOSYNCCACHE)
-		return;
+		return (0);
 
 	/*
 	 * Issue a SYNCHRONIZE CACHE. Address 0, length 0 means "all remaining
@@ -1889,7 +1899,7 @@ sd_flush(struct sd_softc *sc, int flags)
 	xs = scsi_xs_get(link, flags);
 	if (xs == NULL) {
 		SC_DEBUG(link, SDEV_DB1, ("cache sync failed to get xs\n"));
-		return;
+		return (EIO);
 	}
 
 	cmd = (struct scsi_synchronize_cache *)xs->cmd;
@@ -1899,10 +1909,14 @@ sd_flush(struct sd_softc *sc, int flags)
 	xs->timeout = 100000;
 	xs->flags |= SCSI_IGNORE_ILLEGAL_REQUEST;
 
-	if (scsi_xs_sync(xs) == 0)
-		sc->flags &= ~SDF_DIRTY;
-	else
-		SC_DEBUG(link, SDEV_DB1, ("cache sync failed\n"));
+	error = scsi_xs_sync(xs);
 
 	scsi_xs_put(xs);
+
+	if (error)
+		SC_DEBUG(link, SDEV_DB1, ("cache sync failed\n"));
+	else
+		sc->flags &= ~SDF_DIRTY;
+
+	return (error);
 }
diff --git a/sys/sys/dkio.h b/sys/sys/dkio.h
index c774e198250..300a9a7e3c5 100644
--- a/sys/sys/dkio.h
+++ b/sys/sys/dkio.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dkio.h,v 1.9 2011/06/05 18:40:33 matthew Exp $	*/
+/*	$OpenBSD: dkio.h,v 1.10 2017/05/29 14:05:31 sf Exp $	*/
 /*	$NetBSD: dkio.h,v 1.1 1996/01/30 18:21:48 thorpej Exp $	*/
 
 /*
@@ -83,4 +83,6 @@ struct dk_diskmap {
 
 #define	DIOCMAP		_IOWR('d', 119, struct dk_diskmap)
 
+#define	DIOCCACHESYNC	_IOW('d', 120, int)	/* sync cache (force?) */
+
 #endif /* _SYS_DKIO_H_ */