Module Name: src
Committed By: jdolecek
Date: Fri Apr 10 10:30:10 UTC 2020
Modified Files:
src/sys/arch/xen/xen: xbd_xenbus.c
Log Message:
implement DIOCGCACHE - assume if CACHE_FLUSH is supported, write cache
is enabled
convert the sc_cache_flush flag to a feature bit field, and recognize
also barrier and persistent features; print the recognized features
on boot, and remove the warning on DIOCCACHESYNC
To generate a diff of this commit:
cvs rdiff -u -r1.97 -r1.98 src/sys/arch/xen/xen/xbd_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xbd_xenbus.c
diff -u src/sys/arch/xen/xen/xbd_xenbus.c:1.97 src/sys/arch/xen/xen/xbd_xenbus.c:1.98
--- src/sys/arch/xen/xen/xbd_xenbus.c:1.97 Tue Apr 7 11:47:06 2020
+++ src/sys/arch/xen/xen/xbd_xenbus.c Fri Apr 10 10:30:10 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: xbd_xenbus.c,v 1.97 2020/04/07 11:47:06 jdolecek Exp $ */
+/* $NetBSD: xbd_xenbus.c,v 1.98 2020/04/10 10:30:10 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -50,7 +50,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbd_xenbus.c,v 1.97 2020/04/07 11:47:06 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbd_xenbus.c,v 1.98 2020/04/10 10:30:10 jdolecek Exp $");
#include "opt_xen.h"
@@ -150,7 +150,12 @@ struct xbd_xenbus_softc {
uint64_t sc_xbdsize; /* size of disk in DEV_BSIZE */
u_long sc_info; /* VDISK_* */
u_long sc_handle; /* from backend */
- int sc_cache_flush; /* backend supports BLKIF_OP_FLUSH_DISKCACHE */
+ int sc_features;
+#define BLKIF_FEATURE_CACHE_FLUSH 0x1
+#define BLKIF_FEATURE_BARRIER 0x2
+#define BLKIF_FEATURE_PERSISTENT 0x4
+#define BLKIF_FEATURE_BITS \
+ "\20\1CACHE-FLUSH\2BARRIER\3PERSISTENT"
struct evcnt sc_cnt_map_unalign;
};
@@ -509,7 +514,7 @@ xbd_backend_changed(void *arg, XenbusSta
struct xbd_xenbus_softc *sc = device_private((device_t)arg);
struct disk_geom *dg;
- char buf[9];
+ char buf[32];
int s;
DPRINTF(("%s: new backend state %d\n",
device_xname(sc->sc_dksc.sc_dev), new_state));
@@ -569,6 +574,9 @@ xbd_backend_changed(void *arg, XenbusSta
aprint_normal_dev(sc->sc_dksc.sc_dev,
"%s, %d bytes/sect x %" PRIu64 " sectors\n",
buf, (int)dg->dg_secsize, sc->sc_xbdsize);
+ snprintb(buf, sizeof(buf), BLKIF_FEATURE_BITS,
+ sc->sc_features);
+ aprint_normal_dev(sc->sc_dksc.sc_dev, "features %s\n", buf);
/* Discover wedges on this disk. */
dkwedge_discover(&sc->sc_dksc.sc_dkdev);
@@ -588,7 +596,7 @@ xbd_connect(struct xbd_xenbus_softc *sc)
{
int err;
unsigned long long sectors;
- u_long cache_flush;
+ u_long val;
err = xenbus_read_ul(NULL,
sc->sc_xbusd->xbusd_path, "virtual-device", &sc->sc_handle, 10);
@@ -618,13 +626,25 @@ xbd_connect(struct xbd_xenbus_softc *sc)
sc->sc_xbusd->xbusd_otherend);
err = xenbus_read_ul(NULL, sc->sc_xbusd->xbusd_otherend,
- "feature-flush-cache", &cache_flush, 10);
+ "feature-flush-cache", &val, 10);
if (err)
- cache_flush = 0;
- if (cache_flush > 0)
- sc->sc_cache_flush = 1;
- else
- sc->sc_cache_flush = 0;
+ val = 0;
+ if (val > 0)
+ sc->sc_features |= BLKIF_FEATURE_CACHE_FLUSH;
+
+ err = xenbus_read_ul(NULL, sc->sc_xbusd->xbusd_otherend,
+ "feature-barrier", &val, 10);
+ if (err)
+ val = 0;
+ if (val > 0)
+ sc->sc_features |= BLKIF_FEATURE_BARRIER;
+
+ err = xenbus_read_ul(NULL, sc->sc_xbusd->xbusd_otherend,
+ "feature-persistent", &val, 10);
+ if (err)
+ val = 0;
+ if (val > 0)
+ sc->sc_features |= BLKIF_FEATURE_PERSISTENT;
xenbus_switch_state(sc->sc_xbusd, NULL, XenbusStateConnected);
}
@@ -834,16 +854,22 @@ xbdioctl(dev_t dev, u_long cmd, void *da
case DIOCSSTRATEGY:
error = EOPNOTSUPP;
break;
+ case DIOCGCACHE:
+ {
+ /*
+ * Assume there is read & write cache if cache-flush is
+ * supported.
+ */
+ int *bitsp = (int *)data;
+ *bitsp = 0;
+ if (sc->sc_features & BLKIF_FEATURE_CACHE_FLUSH)
+ *bitsp |= DKCACHE_WRITE;
+ error = 0;
+ break;
+ }
case DIOCCACHESYNC:
- if (sc->sc_cache_flush <= 0) {
- if (sc->sc_cache_flush == 0) {
- aprint_verbose_dev(sc->sc_dksc.sc_dev,
- "WARNING: cache flush not supported "
- "by backend\n");
- sc->sc_cache_flush = -1;
- }
+ if ((sc->sc_features & BLKIF_FEATURE_CACHE_FLUSH) == 0)
return EOPNOTSUPP;
- }
s = splbio(); /* XXXSMP */
