Am 29.08.2013 14:38, schrieb Eric Blake:
On 08/29/2013 05:20 AM, Max Reitz wrote:
This patch adds the "amend" option to qemu-img which allows changing
image options on existing image files. It also adds the generic bdrv
implementation which is basically just a wrapper for the image format
specific function.
Signed-off-by: Max Reitz <mre...@redhat.com>
---
+static int img_amend(int argc, char **argv)
+{
+ int c, ret = 0;
+ char *options = NULL;
+ QEMUOptionParameter *create_options = NULL, *options_param = NULL;
+ const char *fmt = NULL, *filename;
+ bool quiet = false;
+ BlockDriverState *bs = NULL;
+
+ for (;;) {
+ c = getopt(argc, argv, "h?qf:o:");
? is not usually listed in the string to getopt() (doing so is not
portable to POSIX). Besides, use of an unknown option (such as -x) will
get mapped to '?' by getopt anyways, so your goal...
+ if (c == -1) {
+ break;
+ }
+
+ switch (c) {
+ case 'h':
+ case '?':
+ help();
+ break;
...of printing help on unknown options is already met without the need
for an explicit '-?' option.
Ah, okay, thanks.
+
+ filename = argv[argc - 1];
+
+ bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
+ if (!bs) {
+ error_report("Could not open image.");
We generally avoid trailing '.' in error messages; it might also be nice
to report WHICH image could not be opened.
Yes, I'll fix it.
+ options_param = parse_option_parameters(options, create_options,
+ options_param);
+ if (options_param == NULL) {
+ error_report("Invalid options for file format '%s'.", fmt);
again, no trailing '.'
+++ b/qemu-img.texi
@@ -282,6 +282,11 @@ sizes accordingly. Failure to do so will result in data
loss!
After using this command to grow a disk image, you must use file system and
partitioning tools inside the VM to actually begin using the new space on the
device.
+
+@item amend [-f @var{fmt}] -o @var{options} @var{filename}
+
+Amends the image format specific @var{options} for the image file
+@var{filename}. Only the format @code{qcow2} supports this.
We might add support for other file formats in the future; we'd have to
remember to update this sentence at that time. Could you use a more
generic statement, such as "not all file formats support this", so we
don't end up with stale docs if we forget to touch it down the road?
Of course.
Max
