From 2e9c1d07ca7609d66fa0433c0eebe8ab0d2508ed Mon Sep 17 00:00:00 2001
From: Jeffrey Cody <jcody@redhat.com>
Date: Tue, 27 May 2014 18:34:03 +0200
Subject: [PATCH 06/13] block: Ignore duplicate or NULL format_name in bdrv_iterate_format

RH-Author: Jeffrey Cody <jcody@redhat.com>
Message-id: <d4929261531a1ad759bbaed14cec6968e554f7c6.1401215469.git.jcody@redhat.com>
Patchwork-id: 59038
O-Subject: [PATCH qemu-kvm RHEL7.1] block: Ignore duplicate or NULL format_name in bdrv_iterate_format
Bugzilla: 1088695 1093983
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

Some block drivers have multiple BlockDriver instances with identical
format_name fields (e.g. gluster, nbd).

Both qemu-img and qemu will use bdrv_iterate_format() to list the
supported formats when a help option is invoked.  As protocols and
formats may register multiple drivers, redundant listings of formats
occur (e.g., "Supported formats: ... gluster gluster gluster gluster ...
").

Since the list of driver formats will be small, this performs a simple
linear search on format_name, and ignores any duplicates.

The end result change is that the iterator will no longer receive
duplicate string names, nor will it receive NULL pointers.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit e855e4fb7b97f7f605e1f44427b98022e39e6f8f)
---

RHEL7 Notes:
Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=7505698
BZ: 1093983
BZ: 1088695

 block.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block.c |   17 ++++++++++++++++-
 1 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/block.c b/block.c
index 4906f6b..43e325e 100644
--- a/block.c
+++ b/block.c
@@ -3402,10 +3402,25 @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
                          void *opaque)
 {
     BlockDriver *drv;
+    int count = 0;
+    const char **formats = NULL;
 
     QLIST_FOREACH(drv, &bdrv_drivers, list) {
-        it(opaque, drv->format_name);
+        if (drv->format_name) {
+            bool found = false;
+            int i = count;
+            while (formats && i && !found) {
+                found = !strcmp(formats[--i], drv->format_name);
+            }
+
+            if (!found) {
+                formats = g_realloc(formats, (count + 1) * sizeof(char *));
+                formats[count++] = drv->format_name;
+                it(opaque, drv->format_name);
+            }
+        }
     }
+    g_free(formats);
 }
 
 BlockDriverState *bdrv_find(const char *name)
-- 
1.7.1