The '--image-opts' flags indicates whether the source filename
includes options. The target filename has to remain in the
plain filename format though, since it needs to be passed to
bdrv_create().  When using --skip-create though, it would be
possible to use image-opts syntax. This adds --target-image-opts
to indicate that the target filename includes options. Currently
this mandates use of the --skip-create flag too.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 qemu-img-cmds.hx |   6 +--
 qemu-img.c       | 131 ++++++++++++++++++++++++++++++++++++-------------------
 qemu-img.texi    |  12 ++++-
 3 files changed, 98 insertions(+), 51 deletions(-)

diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 2488cbe..13fded9 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -40,13 +40,13 @@ STEXI
 ETEXI
 
 DEF("convert", img_convert,
-    "convert [--object objectdef] [--image-opts] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-o options] [-s snapshot_id_or_name] [-l snapshot_param] [-S sparse_size] filename [filename2 [...]] output_filename")
+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-o options] [-s snapshot_id_or_name] [-l snapshot_param] [-S sparse_size] filename [filename2 [...]] output_filename")
 STEXI
-@item convert [--object @var{objectdef}] [--image-opts] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_id_or_name}] [-l @var{snapshot_param}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename}
+@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_id_or_name}] [-l @var{snapshot_param}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename}
 ETEXI
 
 DEF("dd", img_dd,
-    "dd [--image-opts] [-f fmt] [-O output_fmt] [-o options] [bs=block_size] [count=blocks] [skip=blocks] [conv=nocreat,notrunc] if=input of=output")
+    "dd [--image-opts] [--target-image-opts] [-f fmt] [-O output_fmt] [-o options] [bs=block_size] [count=blocks] [skip=blocks] [conv=nocreat,notrunc] if=input of=output")
 STEXI
 @item dd [--image-opts] [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] [conv=nocreat,notrunc] if=@var{input} of=@var{output}
 ETEXI
diff --git a/qemu-img.c b/qemu-img.c
index 39fcf09..dc4c6eb 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -59,6 +59,7 @@ enum {
     OPTION_PATTERN = 260,
     OPTION_FLUSH_INTERVAL = 261,
     OPTION_NO_DRAIN = 262,
+    OPTION_TARGET_IMAGE_OPTS = 263,
 };
 
 typedef enum OutputFormat {
@@ -1765,7 +1766,7 @@ static int img_convert(int argc, char **argv)
     int progress = 0, flags, src_flags;
     bool writethrough, src_writethrough;
     const char *fmt, *out_fmt, *cache, *src_cache, *out_baseimg, *out_filename;
-    BlockDriver *drv, *proto_drv;
+    BlockDriver *drv = NULL, *proto_drv = NULL;
     BlockBackend **blk = NULL, *out_blk = NULL;
     BlockDriverState **bs = NULL, *out_bs = NULL;
     int64_t total_sectors;
@@ -1783,9 +1784,10 @@ static int img_convert(int argc, char **argv)
     QemuOpts *sn_opts = NULL;
     ImgConvertState state;
     bool image_opts = false;
+    bool tgt_image_opts = false;
 
+    out_fmt = NULL;
     fmt = NULL;
-    out_fmt = "raw";
     cache = "unsafe";
     src_cache = BDRV_DEFAULT_CACHE;
     out_baseimg = NULL;
@@ -1796,6 +1798,7 @@ static int img_convert(int argc, char **argv)
             {"help", no_argument, 0, 'h'},
             {"object", required_argument, 0, OPTION_OBJECT},
             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
+            {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
             {0, 0, 0, 0}
         };
         c = getopt_long(argc, argv, "hf:O:B:ce6o:s:l:S:pt:T:qn",
@@ -1900,15 +1903,27 @@ static int img_convert(int argc, char **argv)
         case OPTION_IMAGE_OPTS:
             image_opts = true;
             break;
+        case OPTION_TARGET_IMAGE_OPTS:
+            tgt_image_opts = true;
+            break;
         }
     }
 
+    if (!out_fmt && !tgt_image_opts) {
+        out_fmt = "raw";
+    }
+
     if (qemu_opts_foreach(&qemu_object_opts,
                           user_creatable_add_opts_foreach,
                           NULL, NULL)) {
         goto fail_getopt;
     }
 
+    if (tgt_image_opts && !skip_create) {
+        error_report("--target-image-opts requires use of -n flag");
+        goto fail_getopt;
+    }
+
     /* Initialize before goto out */
     if (quiet) {
         progress = 0;
@@ -1918,7 +1933,7 @@ static int img_convert(int argc, char **argv)
     bs_n = argc - optind - 1;
     out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
 
-    if (options && has_help_option(options)) {
+    if (out_fmt && options && has_help_option(options)) {
         ret = print_block_option_help(out_filename, out_fmt);
         goto out;
     }
@@ -1987,22 +2002,22 @@ static int img_convert(int argc, char **argv)
         goto out;
     }
 
-    /* Find driver and parse its options */
-    drv = bdrv_find_format(out_fmt);
-    if (!drv) {
-        error_report("Unknown file format '%s'", out_fmt);
-        ret = -1;
-        goto out;
-    }
+    if (!skip_create) {
+        /* Find driver and parse its options */
+        drv = bdrv_find_format(out_fmt);
+        if (!drv) {
+            error_report("Unknown file format '%s'", out_fmt);
+            ret = -1;
+            goto out;
+        }
 
-    proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
-    if (!proto_drv) {
-        error_report_err(local_err);
-        ret = -1;
-        goto out;
-    }
+        proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
+        if (!proto_drv) {
+            error_report_err(local_err);
+            ret = -1;
+            goto out;
+        }
 
-    if (!skip_create) {
         if (!drv->create_opts) {
             error_report("Format driver '%s' does not support image creation",
                          drv->format_name);
@@ -2091,12 +2106,18 @@ static int img_convert(int argc, char **argv)
         goto out;
     }
 
-    /* XXX we should allow --image-opts to trigger use of
-     * img_open() here, but then we have trouble with
-     * the bdrv_create() call which takes different params.
-     * Not critical right now, so fix can wait...
-     */
-    out_blk = img_open_file(out_filename, out_fmt, flags, writethrough, quiet);
+    if (skip_create) {
+        out_blk = img_open(tgt_image_opts, out_filename, out_fmt,
+                           flags, writethrough, quiet);
+    } else {
+        /* TODO ultimately we should allow --target-image-opts
+         * to be used even when -n is not given.
+         * That has to wait for bdrv_create to be improved
+         * to allow filenames in option syntax
+         */
+        out_blk = img_open_file(out_filename, out_fmt,
+                                flags, writethrough, quiet);
+    }
     if (!out_blk) {
         ret = -1;
         goto out;
@@ -3946,8 +3967,9 @@ static int img_dd(int argc, char **argv)
     QemuOptsList *create_opts = NULL;
     Error *local_err = NULL;
     bool image_opts = false;
+    bool tgt_image_opts = false;
     int c, i;
-    const char *out_fmt = "raw";
+    const char *out_fmt = NULL;
     const char *fmt = NULL;
     char *optionstr = NULL;
     int64_t size = 0, out_size;
@@ -3982,6 +4004,7 @@ static int img_dd(int argc, char **argv)
         { "help", no_argument, 0, 'h'},
         { "object", required_argument, 0, OPTION_OBJECT},
         { "image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
+        {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
         { 0, 0, 0, 0 }
     };
 
@@ -4028,6 +4051,9 @@ static int img_dd(int argc, char **argv)
         case OPTION_IMAGE_OPTS:
             image_opts = true;
             break;
+        case OPTION_TARGET_IMAGE_OPTS:
+            tgt_image_opts = true;
+            break;
         }
     }
 
@@ -4064,13 +4090,22 @@ static int img_dd(int argc, char **argv)
         arg = NULL;
     }
 
+    if (tgt_image_opts && !(dd.flags & C_NOCREAT)) {
+        error_report("--target-image-opts requires use of -n flag");
+        goto out;
+    }
+
+    if (!out_fmt && !tgt_image_opts) {
+        out_fmt = "raw";
+    }
+
     if (!(dd.flags & C_IF && dd.flags & C_OF)) {
         error_report("Must specify both input and output files");
         ret = -1;
         goto out;
     }
 
-    if (optionstr && has_help_option(optionstr)) {
+    if (out_fmt && optionstr && has_help_option(optionstr)) {
         ret = print_block_option_help(out.filename, out_fmt);
         goto out;
     }
@@ -4088,21 +4123,21 @@ static int img_dd(int argc, char **argv)
         goto out;
     }
 
-    drv = bdrv_find_format(out_fmt);
-    if (!drv) {
-        error_report("Unknown file format");
-        ret = -1;
-        goto out;
-    }
-    proto_drv = bdrv_find_protocol(out.filename, true, &local_err);
+    if (!(dd.flags & C_NOCREAT)) {
+        drv = bdrv_find_format(out_fmt);
+        if (!drv) {
+            error_report("Unknown file format");
+            ret = -1;
+            goto out;
+        }
+        proto_drv = bdrv_find_protocol(out.filename, true, &local_err);
 
-    if (!proto_drv) {
-        error_report_err(local_err);
-        ret = -1;
-        goto out;
-    }
+        if (!proto_drv) {
+            error_report_err(local_err);
+            ret = -1;
+            goto out;
+        }
 
-    if (!(dd.flags & C_NOCREAT)) {
         if (!drv->create_opts) {
             error_report("Format driver '%s' does not support image creation",
                          drv->format_name);
@@ -4152,7 +4187,6 @@ static int img_dd(int argc, char **argv)
 
     if (!(dd.flags & C_NOCREAT)) {
         qemu_opt_set_number(opts, BLOCK_OPT_SIZE, out_size, &error_abort);
-
         ret = bdrv_create(drv, out.filename, opts, &local_err);
         if (ret < 0) {
             error_reportf_err(local_err,
@@ -4163,13 +4197,18 @@ static int img_dd(int argc, char **argv)
         }
     }
 
-    /* TODO, we can't honour --image-opts for the target,
-     * since it needs to be given in a format compatible
-     * with the bdrv_create() call above which does not
-     * support image-opts style.
-     */
-    blk2 = img_open_file(out.filename, out_fmt, BDRV_O_RDWR,
-                         false, false);
+    if (dd.flags & C_NOCREAT) {
+        blk2 = img_open(tgt_image_opts, out.filename, out_fmt,
+                        BDRV_O_RDWR, false, false);
+    } else {
+        /* TODO ultimately we should allow --target-image-opts
+         * to be used even when -n is not given.
+         * That has to wait for bdrv_create to be improved
+         * to allow filenames in option syntax
+         */
+        blk2 = img_open_file(out.filename, out_fmt,
+                             BDRV_O_RDWR, false, false);
+    }
 
     if (!blk2) {
         ret = -1;
diff --git a/qemu-img.texi b/qemu-img.texi
index 01acfb8..bda3cc3 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -45,9 +45,17 @@ keys.
 
 @item --image-opts
 
-Indicates that the @var{filename} parameter is to be interpreted as a
+Indicates that the source @var{filename} parameter is to be interpreted as a
 full option string, not a plain filename. This parameter is mutually
-exclusive with the @var{-f} and @var{-F} parameters.
+exclusive with the @var{-f} parameter.
+
+@item --target-image-opts
+
+Indicates that the target @var{filename} parameter(s) are to be interpreted a
+a full option string, not a plain filename. This parameter is mutually
+exclusive with the @var{-F} or @var{-O} parameters. It is currently required
+to also use the @var{-n} parameter to skip image creation. This restriction
+will be relaxed in a future release.
 
 @item fmt
 is the disk image format. It is guessed automatically in most cases. See below
-- 
2.9.3

On 03.02.2017 13:02, Daniel P. Berrange wrote:
> The '--image-opts' flags indicates whether the source filename
> includes options. The target filename has to remain in the
> plain filename format though, since it needs to be passed to
> bdrv_create().  When using --skip-create though, it would be
> possible to use image-opts syntax. This adds --target-image-opts
> to indicate that the target filename includes options. Currently
> this mandates use of the --skip-create flag too.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  qemu-img-cmds.hx |   6 +--
>  qemu-img.c       | 131 ++++++++++++++++++++++++++++++++++++-------------------
>  qemu-img.texi    |  12 ++++-
>  3 files changed, 98 insertions(+), 51 deletions(-)

Apart from what the commit message says, it also introduces that switch
for dd, which I again don't like too much (quelle surprise), if only
because it requires conv=nocreat and thus patch 5 to be useful.

[...]

> diff --git a/qemu-img.c b/qemu-img.c
> index 39fcf09..dc4c6eb 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c

[...]

> @@ -1918,7 +1933,7 @@ static int img_convert(int argc, char **argv)
>      bs_n = argc - optind - 1;
>      out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
>  
> -    if (options && has_help_option(options)) {
> +    if (out_fmt && options && has_help_option(options)) {

"!out_fmt && options && has_help_option(options)" should probably be an
error.

>          ret = print_block_option_help(out_filename, out_fmt);
>          goto out;
>      }
> @@ -1987,22 +2002,22 @@ static int img_convert(int argc, char **argv)
>          goto out;
>      }
>  
> -    /* Find driver and parse its options */
> -    drv = bdrv_find_format(out_fmt);
> -    if (!drv) {
> -        error_report("Unknown file format '%s'", out_fmt);
> -        ret = -1;
> -        goto out;
> -    }
> +    if (!skip_create) {
> +        /* Find driver and parse its options */
> +        drv = bdrv_find_format(out_fmt);
> +        if (!drv) {
> +            error_report("Unknown file format '%s'", out_fmt);
> +            ret = -1;
> +            goto out;
> +        }
>  
> -    proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
> -    if (!proto_drv) {
> -        error_report_err(local_err);
> -        ret = -1;
> -        goto out;
> -    }
> +        proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
> +        if (!proto_drv) {
> +            error_report_err(local_err);
> +            ret = -1;
> +            goto out;
> +        }
>  
> -    if (!skip_create) {
>          if (!drv->create_opts) {
>              error_report("Format driver '%s' does not support image creation",
>                           drv->format_name);

Compression may be used with -n. This involves the check whether
drv->bdrv_co_pwritev_compressed is NULL or not -- which is bad if drv is
still NULL:

$ ./qemu-img create -f qcow2 foo.qcow2 64M
Formatting 'foo.qcow2', fmt=qcow2 size=67108864 encryption=off
cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ ./qemu-img convert -c -O qcow2 -n null-co:// foo.qcow2
[1]    17179 segmentation fault (core dumped)  ./qemu-img convert -c -O
qcow2 -n null-co:// foo.qcow

Therefore, you should probably only do the check whether compression is
supported if drv is non-NULL; and if it is NULL, do the check again
after the target image has been opened and its driver is known.

[...]

> @@ -4064,13 +4090,22 @@ static int img_dd(int argc, char **argv)
>          arg = NULL;
>      }
>  
> +    if (tgt_image_opts && !(dd.flags & C_NOCREAT)) {
> +        error_report("--target-image-opts requires use of -n flag");

*conv=nocreat

> +        goto out;
> +    }
> +
> +    if (!out_fmt && !tgt_image_opts) {
> +        out_fmt = "raw";
> +    }
> +
>      if (!(dd.flags & C_IF && dd.flags & C_OF)) {
>          error_report("Must specify both input and output files");
>          ret = -1;
>          goto out;
>      }
>  
> -    if (optionstr && has_help_option(optionstr)) {
> +    if (out_fmt && optionstr && has_help_option(optionstr)) {

Same as in img_convert().

>          ret = print_block_option_help(out.filename, out_fmt);
>          goto out;
>      }

[...]

> @@ -4152,7 +4187,6 @@ static int img_dd(int argc, char **argv)
>  
>      if (!(dd.flags & C_NOCREAT)) {
>          qemu_opt_set_number(opts, BLOCK_OPT_SIZE, out_size, &error_abort);
> -
>          ret = bdrv_create(drv, out.filename, opts, &local_err);
>          if (ret < 0) {
>              error_reportf_err(local_err,

I'm not sure whether this hunk is necessary...

[...]

> diff --git a/qemu-img.texi b/qemu-img.texi
> index 01acfb8..bda3cc3 100644
> --- a/qemu-img.texi
> +++ b/qemu-img.texi
> @@ -45,9 +45,17 @@ keys.
>  
>  @item --image-opts
>  
> -Indicates that the @var{filename} parameter is to be interpreted as a
> +Indicates that the source @var{filename} parameter is to be interpreted as a
>  full option string, not a plain filename. This parameter is mutually
> -exclusive with the @var{-f} and @var{-F} parameters.
> +exclusive with the @var{-f} parameter.

-F is correct, that's the one for qemu-img compare, after all (which
takes two source filenames).

> +
> +@item --target-image-opts
> +
> +Indicates that the target @var{filename} parameter(s) are to be interpreted a
> +a full option string, not a plain filename. This parameter is mutually
> +exclusive with the @var{-F} or @var{-O} parameters. It is currently required

-F is unrelated to a target ("output") file.

Max

> +to also use the @var{-n} parameter to skip image creation. This restriction
> +will be relaxed in a future release.
>  
>  @item fmt
>  is the disk image format. It is guessed automatically in most cases. See below
> 

On Fri, Feb 03, 2017 at 11:32:13PM +0100, Max Reitz wrote:
> On 03.02.2017 13:02, Daniel P. Berrange wrote:
> > The '--image-opts' flags indicates whether the source filename
> > includes options. The target filename has to remain in the
> > plain filename format though, since it needs to be passed to
> > bdrv_create().  When using --skip-create though, it would be
> > possible to use image-opts syntax. This adds --target-image-opts
> > to indicate that the target filename includes options. Currently
> > this mandates use of the --skip-create flag too.
> > 
> > Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> > ---
> >  qemu-img-cmds.hx |   6 +--
> >  qemu-img.c       | 131 ++++++++++++++++++++++++++++++++++++-------------------
> >  qemu-img.texi    |  12 ++++-
> >  3 files changed, 98 insertions(+), 51 deletions(-)
> 
> Apart from what the commit message says, it also introduces that switch
> for dd, which I again don't like too much (quelle surprise), if only
> because it requires conv=nocreat and thus patch 5 to be useful.

Once again, I'll drop the 'dd' parts of this patch.

> > @@ -1918,7 +1933,7 @@ static int img_convert(int argc, char **argv)
> >      bs_n = argc - optind - 1;
> >      out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
> >  
> > -    if (options && has_help_option(options)) {
> > +    if (out_fmt && options && has_help_option(options)) {
> 
> "!out_fmt && options && has_help_option(options)" should probably be an
> error.

Ok.

> > @@ -1987,22 +2002,22 @@ static int img_convert(int argc, char **argv)
> >          goto out;
> >      }
> >  
> > -    /* Find driver and parse its options */
> > -    drv = bdrv_find_format(out_fmt);
> > -    if (!drv) {
> > -        error_report("Unknown file format '%s'", out_fmt);
> > -        ret = -1;
> > -        goto out;
> > -    }
> > +    if (!skip_create) {
> > +        /* Find driver and parse its options */
> > +        drv = bdrv_find_format(out_fmt);
> > +        if (!drv) {
> > +            error_report("Unknown file format '%s'", out_fmt);
> > +            ret = -1;
> > +            goto out;
> > +        }
> >  
> > -    proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
> > -    if (!proto_drv) {
> > -        error_report_err(local_err);
> > -        ret = -1;
> > -        goto out;
> > -    }
> > +        proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
> > +        if (!proto_drv) {
> > +            error_report_err(local_err);
> > +            ret = -1;
> > +            goto out;
> > +        }
> >  
> > -    if (!skip_create) {
> >          if (!drv->create_opts) {
> >              error_report("Format driver '%s' does not support image creation",
> >                           drv->format_name);
> 
> Compression may be used with -n. This involves the check whether
> drv->bdrv_co_pwritev_compressed is NULL or not -- which is bad if drv is
> still NULL:
> 
> $ ./qemu-img create -f qcow2 foo.qcow2 64M
> Formatting 'foo.qcow2', fmt=qcow2 size=67108864 encryption=off
> cluster_size=65536 lazy_refcounts=off refcount_bits=16
> $ ./qemu-img convert -c -O qcow2 -n null-co:// foo.qcow2
> [1]    17179 segmentation fault (core dumped)  ./qemu-img convert -c -O
> qcow2 -n null-co:// foo.qcow
> 
> Therefore, you should probably only do the check whether compression is
> supported if drv is non-NULL; and if it is NULL, do the check again
> after the target image has been opened and its driver is known.

Oh, yes, that's a fun combination. I'll do that.


> > diff --git a/qemu-img.texi b/qemu-img.texi
> > index 01acfb8..bda3cc3 100644
> > --- a/qemu-img.texi
> > +++ b/qemu-img.texi
> > @@ -45,9 +45,17 @@ keys.
> >  
> >  @item --image-opts
> >  
> > -Indicates that the @var{filename} parameter is to be interpreted as a
> > +Indicates that the source @var{filename} parameter is to be interpreted as a
> >  full option string, not a plain filename. This parameter is mutually
> > -exclusive with the @var{-f} and @var{-F} parameters.
> > +exclusive with the @var{-f} parameter.
> 
> -F is correct, that's the one for qemu-img compare, after all (which
> takes two source filenames).
> 
> > +
> > +@item --target-image-opts
> > +
> > +Indicates that the target @var{filename} parameter(s) are to be interpreted a
> > +a full option string, not a plain filename. This parameter is mutually
> > +exclusive with the @var{-F} or @var{-O} parameters. It is currently required
> 
> -F is unrelated to a target ("output") file.

Opps, yes.

Regards,
Daniel
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