From 8a53023561ad1fdc87104ef15494803ae00e069b Mon Sep 17 00:00:00 2001
From: Fam Zheng <famz@redhat.com>
Date: Mon, 14 Jul 2014 01:05:21 -0500
Subject: [CHANGE 21/29] block: Improve driver whitelist checks
To: rhvirt-patches@redhat.com,
    jen@redhat.com

RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1405299921-2619-1-git-send-email-famz@redhat.com>
Patchwork-id: 59871
O-Subject: [RHEL-7 qemu-kvm PATCH] block: Improve driver whitelist checks
Bugzilla: 999789
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Kevin Wolf <kwolf@redhat.com>

Brew:     https://brewweb.devel.redhat.com/taskinfo?taskID=7695744
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=999789

The main intent of this patch is to consolidate the whitelist checks to
a single point in the code instead of spreading it everywhere. This adds
a nicer error message for read-only whitelisting, too, in places where
it was still missing.

The patch also contains a bonus bug fix: By finding the format first in
bdrv_open() and then independently checking against the whitelist only
later, we avoid the case that use of a non-whitelisted format results in
probing rather than an error message. Previously, this could happen when
using the driver=... option.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
(cherry picked from commit 8f94a6e40e46cbc8e8014da825d25824b1803b34)
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: jen <jen@redhat.com>

Conflicts:
	blockdev.c
Error report is different.
---
 block.c    | 10 +++++++---
 blockdev.c |  2 +-
 2 files changed, 8 insertions(+), 4 deletions(-)

Signed-off-by: jen <jen@redhat.com>
---
 block.c    | 10 +++++++---
 blockdev.c |  2 +-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 43e325e..a2e95f6 100644
--- a/block.c
+++ b/block.c
@@ -786,7 +786,11 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     bs->read_only = !(open_flags & BDRV_O_RDWR);
 
     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
-        error_setg(errp, "Driver '%s' is not whitelisted", drv->format_name);
+        error_setg(errp,
+                   !bs->read_only && bdrv_is_whitelisted(drv, true)
+                        ? "Driver '%s' can only be used for read-only devices"
+                        : "Driver '%s' is not whitelisted",
+                   drv->format_name);
         return -ENOTSUP;
     }
 
@@ -908,7 +912,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
     /* Find the right block driver */
     drvname = qdict_get_try_str(options, "driver");
     if (drvname) {
-        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
+        drv = bdrv_find_format(drvname);
         if (!drv) {
             error_setg(errp, "Unknown driver '%s'", drvname);
         }
@@ -1177,7 +1181,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     /* Find the right image format driver */
     drvname = qdict_get_try_str(options, "driver");
     if (drvname) {
-        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
+        drv = bdrv_find_format(drvname);
         qdict_del(options, "driver");
     }
 
diff --git a/blockdev.c b/blockdev.c
index e51203c..aa5d0a6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -414,7 +414,7 @@ static DriveInfo *blockdev_init(QDict *bs_opts,
             goto early_err;
         }
 
-        drv = bdrv_find_whitelisted_format(buf, ro);
+        drv = bdrv_find_format(buf);
         if (!drv) {
             error_setg(errp, "'%s' invalid format", buf);
             goto early_err;
-- 
1.9.3