From 2c7c1728da1a293eb1022b1a6f656840f1f1c50b Mon Sep 17 00:00:00 2001
From: Uri Lublin <uril@redhat.com>
Date: Tue, 3 Mar 2009 16:27:27 +0200
Subject: [PATCH 8/8] qemu-img: adding a "-F base_fmt" option to "qemu-img create -b"

If the user specifies the backing file format,
then when opening the backing file, there is no need
to probe the (backing file) image to figure out its format.

This follows my previous patch implementing bdrv_create2
which keeps (for qcow2 only) the backing file format
as a qcow2-extension

Suggested by Daniel P. Berrange.

Signed-off-by: Uri Lublin <uril@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
RH-Upstream-status: pending
Bugzilla: 484080
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Dor Laor <dlaor@redhat.com>
---
 qemu/qemu-img.c    |   24 ++++++++++++++++++++----
 qemu/qemu-img.texi |    4 +++-
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/qemu/qemu-img.c b/qemu/qemu-img.c
index faf5d3b..6185197 100644
--- a/qemu/qemu-img.c
+++ b/qemu/qemu-img.c
@@ -25,6 +25,7 @@
 #include "osdep.h"
 #include "block_int.h"
 #include <assert.h>
+#include <stdio.h>
 
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
@@ -57,7 +58,7 @@ static void help(void)
            "QEMU disk image utility\n"
            "\n"
            "Command syntax:\n"
-           "  create [-e] [-6] [-b base_image] [-f fmt] filename [size]\n"
+           "  create [-e] [-6] [-F fmt] [-b base_image] [-f fmt] filename [size]\n"
            "  commit [-f fmt] filename\n"
            "  convert [-c] [-e] [-6] [-f fmt] [-O output_fmt] [-B output_base_image] filename [filename2 [...]] output_filename\n"
            "  info [-f fmt] filename\n"
@@ -215,6 +216,7 @@ static int img_create(int argc, char **argv)
 {
     int c, ret, flags;
     const char *fmt = "raw";
+    const char *base_fmt = NULL;
     const char *filename;
     const char *base_filename = NULL;
     uint64_t size;
@@ -223,13 +225,16 @@ static int img_create(int argc, char **argv)
 
     flags = 0;
     for(;;) {
-        c = getopt(argc, argv, "b:f:he6");
+        c = getopt(argc, argv, "F:b:f:he6");
         if (c == -1)
             break;
         switch(c) {
         case 'h':
             help();
             break;
+        case 'F':
+            base_fmt = optarg;
+            break;
         case 'b':
             base_filename = optarg;
             break;
@@ -250,7 +255,15 @@ static int img_create(int argc, char **argv)
     size = 0;
     if (base_filename) {
         BlockDriverState *bs;
-        bs = bdrv_new_open(base_filename, NULL);
+        BlockDriver *base_drv = NULL;
+
+        if (base_fmt) {
+            base_drv = bdrv_find_format(base_fmt);
+            if (base_drv == NULL)
+                error("Unknown basefile format '%s'", base_fmt);
+        }
+
+        bs = bdrv_new_open(base_filename, base_fmt);
         bdrv_get_geometry(bs, &size);
         size *= 512;
         bdrv_delete(bs);
@@ -281,9 +294,12 @@ static int img_create(int argc, char **argv)
     if (base_filename) {
         printf(", backing_file=%s",
                base_filename);
+         if (base_fmt)
+             printf(", backing_fmt=%s",
+                    base_fmt);
     }
     printf(", size=%" PRIu64 " kB\n", size / 1024);
-    ret = bdrv_create(drv, filename, size / 512, base_filename, flags);
+    ret = bdrv_create2(drv, filename, size / 512, base_filename, base_fmt, flags);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
             error("Formatting or formatting option not supported for file format '%s'", fmt);
diff --git a/qemu/qemu-img.texi b/qemu/qemu-img.texi
index 1c0504b..eaeaf07 100644
--- a/qemu/qemu-img.texi
+++ b/qemu/qemu-img.texi
@@ -8,7 +8,7 @@ usage: qemu-img command [command options]
 
 The following commands are supported:
 @table @option
-@item create [-e] [-6] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}]
+@item create [-e] [-6] [-F @var{base_fmt}] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}]
 @item commit [-f @var{fmt}] @var{filename}
 @item convert [-c] [-e] [-6] [-f @var{fmt}] [-O @var{output_fmt}] [-B @var{output_base_image}] @var{filename} [@var{filename2} [...]] @var{output_filename}
 @item info [-f @var{fmt}] @var{filename}
@@ -26,6 +26,8 @@ forces the output image to be created as a copy on write
 image of the specified base image; @code{output_base_image} should have the same
 content as the input's base image, however the path, image format, etc may
 differ
+@item base_fmt
+is the disk image format of @var{base_image}. for more information look at @var{fmt}
 @item fmt
 is the disk image format. It is guessed automatically in most cases. The following formats are supported:
 
-- 
1.6.1