block: Save errno before error_setg_errno

error_setg_errno() may overwrite errno; therefore, its value should be
read before calling that function and not afterwards.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

diff --git a/block.c b/block.c
index 58efb5b4e474b30c87692557c6bd63e526ad693a..0e96a223a6e4e55dced699713c36fd82598500a1 100644 (file)
--- a/block.c
+++ b/block.c
@@ -1084,8 +1084,8 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
             snprintf(backing_filename, sizeof(backing_filename),
                      "%s", filename);
         } else if (!realpath(filename, backing_filename)) {
-            error_setg_errno(errp, errno, "Could not resolve path '%s'", filename);
             ret = -errno;
+            error_setg_errno(errp, errno, "Could not resolve path '%s'", filename);
             goto fail;
         }