[Qemu-devel] [PATCH] qemu-io: New command map

[Qemu-devel] [PATCH] qemu-io: New command map

[Kevin Wolf]

The new map command in qemu-io lists all allocated/unallocated areas in an
image file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io.c |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index b4e5cc8..169dd51 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -1443,6 +1443,43 @@ static const cmdinfo_t alloc_cmd = {
 };
 
 static int
+map_f(int argc, char **argv)
+{
+       int64_t offset;
+       int nb_sectors;
+       char s1[64];
+       int num;
+       int ret;
+       const char *retstr;
+
+       offset = 0;
+       nb_sectors = bs->total_sectors;
+
+       do {
+               ret = bdrv_is_allocated(bs, offset, nb_sectors, &num);
+               retstr = ret ? "    allocated" : "not allocated";
+               cvtstr(offset << 9ULL, s1, sizeof(s1));
+               printf("[% 24" PRId64 "] % 8d/% 8d sectors %s at offset %s (%d)\n",
+                       offset << 9ULL, num, nb_sectors, retstr, s1, ret);
+
+               offset += num;
+               nb_sectors -= num;
+       } while(offset < bs->total_sectors);
+
+       return 0;
+}
+
+static const cmdinfo_t map_cmd = {
+       .name           = "map",
+       .argmin         = 0,
+       .argmax         = 0,
+       .cfunc          = map_f,
+       .args           = "",
+       .oneline        = "prints the allocated areas of a file",
+};
+
+
+static int
 close_f(int argc, char **argv)
 {
 	bdrv_close(bs);
@@ -1680,6 +1717,7 @@ int main(int argc, char **argv)
 	add_command(&length_cmd);
 	add_command(&info_cmd);
 	add_command(&alloc_cmd);
+	add_command(&map_cmd);
 
 	add_args_command(init_args_command);
 	add_check_command(init_check_command);
-- 
1.7.2.2

Re: [Qemu-devel] [PATCH] qemu-io: New command map

[Stefan Hajnoczi]

On Tue, Sep 21, 2010 at 12:01 PM, Kevin Wolf <kwolf@redhat.com> wrote:
> The new map command in qemu-io lists all allocated/unallocated areas in an
> image file.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  qemu-io.c |   38 ++++++++++++++++++++++++++++++++++++++
>  1 files changed, 38 insertions(+), 0 deletions(-)
>
> diff --git a/qemu-io.c b/qemu-io.c
> index b4e5cc8..169dd51 100644
> --- a/qemu-io.c
> +++ b/qemu-io.c
> @@ -1443,6 +1443,43 @@ static const cmdinfo_t alloc_cmd = {
>  };
>
>  static int
> +map_f(int argc, char **argv)
> +{
> +       int64_t offset;
> +       int nb_sectors;
> +       char s1[64];
> +       int num;
> +       int ret;
> +       const char *retstr;
> +
> +       offset = 0;
> +       nb_sectors = bs->total_sectors;

total_sectors is int64_t but nb_sectors is int.  A >1 TB image with
will have nb_sectors > 0x80000000.  The safest solution is to use
int64_t and cap the nb_sectors argument at INT_MAX per iteration.

Stefan