Subject: CDROM removable media-present attribute plus handling code
From: plc@novell.com
Patch-mainline: obsolete
References: 159907
--- sle11sp1-2010-03-22.orig/drivers/xen/blkback/Makefile 2009-06-09 15:01:37.000000000 +0200
+++ sle11sp1-2010-03-22/drivers/xen/blkback/Makefile 2009-06-09 15:50:31.000000000 +0200
@@ -1,4 +1,4 @@
obj-$(CONFIG_XEN_BLKDEV_BACKEND) := blkbk.o
obj-$(CONFIG_XEN_BLKBACK_PAGEMAP) += blkback-pagemap.o
-blkbk-y := blkback.o xenbus.o interface.o vbd.o
+blkbk-y := blkback.o xenbus.o interface.o vbd.o cdrom.o
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ sle11sp1-2010-03-22/drivers/xen/blkback/cdrom.c 2010-03-22 12:54:41.000000000 +0100
@@ -0,0 +1,162 @@
+/******************************************************************************
+ * blkback/cdrom.c
+ *
+ * Routines for managing cdrom watch and media-present attribute of a
+ * cdrom type virtual block device (VBD).
+ *
+ * Copyright (c) 2003-2005, Keir Fraser & Steve Hand
+ * Copyright (c) 2007 Pat Campbell
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#undef DPRINTK
+#define DPRINTK(_f, _a...) \
+ printk("(%s() file=%s, line=%d) " _f "\n", \
+ __PRETTY_FUNCTION__, __FILE__ , __LINE__ , ##_a )
+
+
+#define MEDIA_PRESENT "media-present"
+
+static void cdrom_media_changed(struct xenbus_watch *, const char **, unsigned int);
+
+/**
+ * Writes media-present=1 attribute for the given vbd device if not
+ * already there
+ */
+static int cdrom_xenstore_write_media_present(struct backend_info *be)
+{
+ struct xenbus_device *dev = be->dev;
+ struct xenbus_transaction xbt;
+ int err;
+ int media_present;
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, MEDIA_PRESENT, "%d",
+ &media_present);
+ if (0 < err) {
+ DPRINTK("already written err%d", err);
+ return(0);
+ }
+ media_present = 1;
+
+again:
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ return(-1);
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, MEDIA_PRESENT, "%d", media_present );
+ if (err) {
+ xenbus_dev_fatal(dev, err, "writing %s/%s",
+ dev->nodename, MEDIA_PRESENT);
+ goto abort;
+ }
+ err = xenbus_transaction_end(xbt, 0);
+ if (err == -EAGAIN)
+ goto again;
+ if (err)
+ xenbus_dev_fatal(dev, err, "ending transaction");
+ return 0;
+ abort:
+ xenbus_transaction_end(xbt, 1);
+ return -1;
+}
+
+/**
+ *
+ */
+static int cdrom_is_type(struct backend_info *be)
+{
+ DPRINTK("type:%x", be->blkif->vbd.type );
+ return (be->blkif->vbd.type & VDISK_CDROM)
+ && (be->blkif->vbd.type & GENHD_FL_REMOVABLE);
+}
+
+/**
+ *
+ */
+void cdrom_add_media_watch(struct backend_info *be)
+{
+ struct xenbus_device *dev = be->dev;
+ int err;
+
+ DPRINTK("nodename:%s", dev->nodename);
+ if (cdrom_is_type(be)) {
+ DPRINTK("is a cdrom");
+ if ( cdrom_xenstore_write_media_present(be) == 0 ) {
+ DPRINTK( "xenstore wrote OK");
+ err = xenbus_watch_path2(dev, dev->nodename, MEDIA_PRESENT,
+ &be->cdrom_watch,
+ cdrom_media_changed);
+ if (err)
+ DPRINTK( "media_present watch add failed" );
+ }
+ }
+}
+
+/**
+ * Callback received when the "media_present" xenstore node is changed
+ */
+static void cdrom_media_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ int err;
+ unsigned media_present;
+ struct backend_info *be
+ = container_of(watch, struct backend_info, cdrom_watch);
+ struct xenbus_device *dev = be->dev;
+
+ if (!cdrom_is_type(be)) {
+ DPRINTK("callback not for a cdrom" );
+ return;
+ }
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, MEDIA_PRESENT, "%d",
+ &media_present);
+ if (err == 0 || err == -ENOENT) {
+ DPRINTK("xenbus_read of cdrom media_present node error:%d",err);
+ return;
+ }
+
+ if (media_present == 0)
+ vbd_free(&be->blkif->vbd);
+ else {
+ char *p = strrchr(dev->otherend, '/') + 1;
+ long handle = simple_strtoul(p, NULL, 0);
+
+ if (!be->blkif->vbd.bdev) {
+ err = vbd_create(be->blkif, handle, be->major, be->minor,
+ !strchr(be->mode, 'w'), 1);
+ if (err) {
+ be->major = be->minor = 0;
+ xenbus_dev_fatal(dev, err, "creating vbd structure");
+ return;
+ }
+ }
+ }
+}
--- sle11sp1-2010-03-22.orig/drivers/xen/blkback/common.h 2010-03-22 12:20:19.000000000 +0100
+++ sle11sp1-2010-03-22/drivers/xen/blkback/common.h 2010-03-22 12:54:11.000000000 +0100
@@ -106,6 +106,7 @@ struct backend_info
struct xenbus_device *dev;
blkif_t *blkif;
struct xenbus_watch backend_watch;
+ struct xenbus_watch cdrom_watch;
unsigned major;
unsigned minor;
char *mode;
@@ -152,4 +153,7 @@ int blkif_schedule(void *arg);
int blkback_barrier(struct xenbus_transaction xbt,
struct backend_info *be, int state);
+/* cdrom media change */
+void cdrom_add_media_watch(struct backend_info *be);
+
#endif /* __BLKIF__BACKEND__COMMON_H__ */
--- sle11sp1-2010-03-22.orig/drivers/xen/blkback/vbd.c 2009-11-06 10:52:09.000000000 +0100
+++ sle11sp1-2010-03-22/drivers/xen/blkback/vbd.c 2010-03-22 12:53:45.000000000 +0100
@@ -108,6 +108,9 @@ int vbd_translate(struct phys_req *req,
if ((operation != READ) && vbd->readonly)
goto out;
+ if (vbd->bdev == NULL)
+ goto out;
+
if (unlikely((req->sector_number + req->nr_sects) > vbd_sz(vbd)))
goto out;
--- sle11sp1-2010-03-22.orig/drivers/xen/blkback/xenbus.c 2010-03-22 12:53:34.000000000 +0100
+++ sle11sp1-2010-03-22/drivers/xen/blkback/xenbus.c 2010-03-22 12:54:58.000000000 +0100
@@ -187,6 +187,12 @@ static int blkback_remove(struct xenbus_
be->backend_watch.node = NULL;
}
+ if (be->cdrom_watch.node) {
+ unregister_xenbus_watch(&be->cdrom_watch);
+ kfree(be->cdrom_watch.node);
+ be->cdrom_watch.node = NULL;
+ }
+
if (be->blkif) {
blkif_disconnect(be->blkif);
vbd_free(&be->blkif->vbd);
@@ -343,6 +349,9 @@ static void backend_changed(struct xenbu
/* We're potentially connected now */
update_blkif_status(be->blkif);
+
+ /* Add watch for cdrom media status if necessay */
+ cdrom_add_media_watch(be);
}
}
