From: Andrew Jones <drjones@redhat.com>
Date: Thu, 2 Dec 2010 17:34:11 -0500
Subject: Revert: [xen] cd-rom drive does not recognize new media
Message-id: <1291311252-8227-2-git-send-email-drjones@redhat.com>
Patchwork-id: 29825
O-Subject: [RHEL5.6 PATCH 1/2] Revert "[xen] cd-rom drive does not recognize new
media"
Bugzilla: 635638
CVE: CVE-2010-4238
This reverts commit 0ceaa9b98503596145b22e6383b073cc1e52b523.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=635638
Signed-off-by: Jarod Wilson <jarod@redhat.com>
diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h
index a18178c..785e482 100644
--- a/drivers/xen/blkback/common.h
+++ b/drivers/xen/blkback/common.h
@@ -42,7 +42,6 @@
#include <xen/blkif.h>
#include <xen/gnttab.h>
#include <xen/driver_util.h>
-#include <xen/xenbus.h>
#define DPRINTK(_f, _a...) \
pr_debug("(file=%s, line=%d) " _f, \
@@ -110,7 +109,7 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn);
/* Create a vbd. */
int vbd_create(blkif_t *blkif, blkif_vdev_t vdevice, unsigned major,
- unsigned minor, int readonly, struct xenbus_device *dev);
+ unsigned minor, int readonly);
void vbd_free(struct vbd *vbd);
unsigned long long vbd_size(struct vbd *vbd);
diff --git a/drivers/xen/blkback/vbd.c b/drivers/xen/blkback/vbd.c
index 495919a..c1862ce 100644
--- a/drivers/xen/blkback/vbd.c
+++ b/drivers/xen/blkback/vbd.c
@@ -36,97 +36,6 @@
#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
(_v)->bdev->bd_part->nr_sects : (_v)->bdev->bd_disk->capacity)
-/*
- * Structure holding dummy device information. This structure is shared by
- * all dummy devices as it is used only to fullfil driver requirements and
- * is not significant for guest.
- */
-static struct block_device dummy_dev;
-
-/*
- * Function copies device structure taken as argument to dummy structure
- * that is used in case we want to close original device. Function sets
- * all pointer members to 0, except block_device.bd_disk attribute that
- * is used by blkback driver so has to be accessible.
- */
-struct block_device* vbd_dev_dummy_copy(const struct block_device* bdev)
-{
- static struct gendisk dummy_disk;
-
- memcpy(&dummy_dev,bdev,sizeof(struct block_device));
- memcpy(&dummy_disk,bdev->bd_disk,sizeof(struct gendisk));
-
- dummy_dev.bd_inode = NULL;
- dummy_dev.bd_holder = NULL;
- dummy_dev.bd_contains = NULL;
- dummy_dev.bd_part = NULL;
- dummy_dev.bd_inode_backing_dev_info = NULL;
- dummy_dev.bd_inodes.next = &dummy_dev.bd_inodes;
- dummy_dev.bd_inodes.prev = &dummy_dev.bd_inodes;
- dummy_dev.bd_list.next = &dummy_dev.bd_list;
- dummy_dev.bd_list.prev = &dummy_dev.bd_list;
-#ifdef CONFIG_SYSFS
- dummy_dev.bd_holder_list.next = &dummy_dev.bd_holder_list;
- dummy_dev.bd_holder_list.prev = &dummy_dev.bd_holder_list;
-#endif
- dummy_dev.bd_disk = &dummy_disk;
- dummy_disk.part = NULL;
- dummy_disk.fops = NULL;
- dummy_disk.queue = NULL;
- dummy_disk.private_data = NULL;
- dummy_disk.driverfs_dev = NULL;
- dummy_disk.holder_dir = NULL;
- dummy_disk.slave_dir = NULL;
- dummy_disk.random = NULL;
-#ifdef CONFIG_SMP
- dummy_disk.dkstats = NULL;
-#endif
-
- return &dummy_dev;
-}
-
-/*
- * Function checks xenstore if device taken as argument is used in
- * hvm. In that case returns 1, otherwise returns 0.
- *
- * For check is used /vm/<uuid>/image record. This contains string
- * that describes guest.
- */
-int vbd_is_hvm(struct xenbus_device *dev)
-{
- int id,err;
- char buf[1024];
- char *uuid, *image;
- int ret = 0;
-
- err = xenbus_scanf(XBT_NIL, dev->nodename, "frontend-id", "%d", &id);
- if (err != 1) {
- xenbus_dev_fatal(dev, err, "Can't read frontend-id");
- return ret;
- }
-
- sprintf(buf, "/local/domain/%d", id);
- uuid = xenbus_read(XBT_NIL, buf, "vm", NULL);
- if (!uuid) {
- xenbus_dev_fatal(dev, err, "Can't read domain uuid");
- return ret;
- }
-
- sprintf(buf, "%s", uuid);
- image = xenbus_read(XBT_NIL, buf, "image", NULL);
-
- if (image && !IS_ERR(image)) {
- if (strstr(image, "(hvm"))
- ret = 1;
- kfree(image);
- }
-
- kfree(uuid);
-
- return ret;
-}
-
-
unsigned long long vbd_size(struct vbd *vbd)
{
return vbd_sz(vbd);
@@ -143,7 +52,7 @@ unsigned long vbd_secsize(struct vbd *vbd)
}
int vbd_create(blkif_t *blkif, blkif_vdev_t handle, unsigned major,
- unsigned minor, int readonly, struct xenbus_device *dev)
+ unsigned minor, int readonly)
{
struct vbd *vbd;
struct block_device *bdev;
@@ -173,28 +82,8 @@ int vbd_create(blkif_t *blkif, blkif_vdev_t handle, unsigned major,
return -ENOENT;
}
- if (vbd->bdev->bd_disk->flags & GENHD_FL_CD) {
+ if (vbd->bdev->bd_disk->flags & GENHD_FL_CD)
vbd->type |= VDISK_CDROM;
-/*
- * When a blkback device is plugged in, blkback driver uses open_by_devnum
- * to obtain reference to a block_device structure describing device. Calling
- * open_by_devnum increase use counter. Cdrom driver do not reallocate read
- * buffer after medium change until use count is set to 0. In case of HVM guest
- * qemu opens/close its own handle from user space instead of using handle hold
- * by blkback driver. This behavior leads to situation when use counter's
- * minimal value is 1 and so read buffer is not reallocate and disk size of
- * previous medium is used. When new medium is bigger than old one, only part
- * equal to old medium size is accessible.
- * As blkback handle is not needed outside blkback driver and blkback driver
- * use this handle only for updating status after plugging in, fake structure
- * can be used to fullfil requirements of blkback driver. Original structure
- * is returned to system so use counter is lowered by one and can be 0.
- */
- if (vbd_is_hvm(dev)) {
- vbd->bdev = vbd_dev_dummy_copy(bdev);
- blkdev_put(bdev);
- }
- }
if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE)
vbd->type |= VDISK_REMOVABLE;
@@ -205,7 +94,7 @@ int vbd_create(blkif_t *blkif, blkif_vdev_t handle, unsigned major,
void vbd_free(struct vbd *vbd)
{
- if (vbd->bdev && vbd->bdev != &dummy_dev)
+ if (vbd->bdev)
blkdev_put(vbd->bdev);
vbd->bdev = NULL;
}
diff --git a/drivers/xen/blkback/xenbus.c b/drivers/xen/blkback/xenbus.c
index cfc9f98..8962f6e 100644
--- a/drivers/xen/blkback/xenbus.c
+++ b/drivers/xen/blkback/xenbus.c
@@ -306,7 +306,7 @@ static void backend_changed(struct xenbus_watch *watch,
be->minor = minor;
err = vbd_create(be->blkif, handle, major, minor,
- (NULL == strchr(be->mode, 'w')),dev);
+ (NULL == strchr(be->mode, 'w')));
if (err) {
be->major = be->minor = 0;
xenbus_dev_fatal(dev, err, "creating vbd structure");
