qemu-img: adding a "-F base_fmt" option to "qemu-img create -b" (Uri Lublin)

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 patches 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: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6910 c046a42c-6fe2-441c-8c8c-71466251a162

qemu-img: adding a "-F base_fmt" option to "qemu-img create -b" (Uri Lublin)
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 patches 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: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6910 c046a42c-6fe2-441c-8c8c-71466251a162
aliguori
1 parent f965509c
Showing 2 changed files with 23 additions and 5 deletions
qemu-img.c
qemu-img.texi
@@ -25,6 +25,7 @@
 #include "osdep.h"
 #include "block_int.h"
 #include <assert.h>
+#include <stdio.h>
 #ifdef _WIN32
 #include <windows.h>
@@ -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"
@@ -217,6 +218,7 @@ 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;
@@ -226,13 +228,16 @@ 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;
@@ -253,7 +258,15 @@ 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);
@@ -284,9 +297,12 @@ 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);
@@ -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}
@@ -27,6 +27,8 @@ 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: