[Qemu-stable] [PATCH 03/43] block/vvfat: qcow driver may not be found

[Michael Roth]

From: Max Reitz <address@hidden>

Although virtually impossible right now, bdrv_find_format("qcow") may
fail. The vvfat block driver should heed that case.

Cc: address@hidden
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Kevin Wolf <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
(cherry picked from commit 1bcb15cf776a57e8963072c1919a59a90aea8e94)
Signed-off-by: Michael Roth <address@hidden>
---
 block/vvfat.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/block/vvfat.c b/block/vvfat.c
index cefe3a4..e34a789 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -2917,6 +2917,12 @@ static int enable_write_target(BDRVVVFATState *s, Error 
**errp)
     }
 
     bdrv_qcow = bdrv_find_format("qcow");
+    if (!bdrv_qcow) {
+        error_setg(errp, "Failed to locate qcow driver");
+        ret = -ENOENT;
+        goto err;
+    }
+
     opts = qemu_opts_create(bdrv_qcow->create_opts, NULL, 0, &error_abort);
     qemu_opt_set_number(opts, BLOCK_OPT_SIZE, s->sector_count * 512);
     qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, "fat:");
-- 
1.9.1