Re: [Libguestfs] [libnbd PATCH v3 13/22] dump: Update nbddump to use 64-bit block status

[Richard W.M. Jones]

On Thu, May 25, 2023 at 08:00:59AM -0500, Eric Blake wrote:
> Although our use of "base:allocation" doesn't require the use of the
> 64-bit API for flags, we might perform slightly faster for a server
> that does give us 64-bit extent lengths.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  dump/dump.c | 27 ++++++++++++++-------------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/dump/dump.c b/dump/dump.c
> index b4aebe84..71053277 100644
> --- a/dump/dump.c
> +++ b/dump/dump.c
> @@ -38,7 +38,7 @@
>  #include "version.h"
>  #include "vector.h"
> 
> -DEFINE_VECTOR_TYPE (uint32_vector, uint32_t);
> +DEFINE_VECTOR_TYPE (uint64_vector, uint64_t);
> 
>  static const char *progname;
>  static struct nbd_handle *nbd;
> @@ -262,10 +262,10 @@ catch_signal (int sig)
>  static int
>  extent_callback (void *user_data, const char *metacontext,
>                   uint64_t offset,
> -                 uint32_t *entries, size_t nr_entries,
> +                 nbd_extent *entries, size_t nr_entries,
>                   int *error)
>  {
> -  uint32_vector *list = user_data;
> +  uint64_vector *list = user_data;
>    size_t i;
> 
>    if (strcmp (metacontext, LIBNBD_CONTEXT_BASE_ALLOCATION) != 0)
> @@ -273,7 +273,8 @@ extent_callback (void *user_data, const char *metacontext,
> 
>    /* Just append the entries we got to the list. */
>    for (i = 0; i < nr_entries; ++i) {
> -    if (uint32_vector_append (list, entries[i]) == -1) {
> +    if (uint64_vector_append (list, entries[i].length) == -1 ||
> +        uint64_vector_append (list, entries[i].flags) == -1) {
>        perror ("realloc");
>        exit (EXIT_FAILURE);
>      }
> @@ -284,7 +285,7 @@ extent_callback (void *user_data, const char *metacontext,
>  static bool
>  test_all_zeroes (uint64_t offset, size_t count)
>  {
> -  uint32_vector entries = empty_vector;
> +  uint64_vector entries = empty_vector;
>    size_t i;
>    uint64_t count_read;
> 
> @@ -296,22 +297,22 @@ test_all_zeroes (uint64_t offset, size_t count)
>     * false, causing the main code to do a full read.  We could be
>     * smarter and keep asking the server (XXX).
>     */
> -  if (nbd_block_status (nbd, count, offset,
> -                        (nbd_extent_callback) {
> -                          .callback = extent_callback,
> -                          .user_data = &entries },
> -                        0) == -1) {
> +  if (nbd_block_status_64 (nbd, count, offset,
> +                           (nbd_extent64_callback) {
> +                             .callback = extent_callback,
> +                             .user_data = &entries },
> +                           0) == -1) {
>      fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
>      exit (EXIT_FAILURE);
>    }
> 
>    count_read = 0;
>    for (i = 0; i < entries.len; i += 2) {
> -    uint32_t len = entries.ptr[i];
> -    uint32_t type = entries.ptr[i+1];
> +    uint64_t len = entries.ptr[i];
> +    uint64_t type = entries.ptr[i+1];
> 
>      count_read += len;
> -    if (!(type & 2))            /* not zero */
> +    if (!(type & LIBNBD_STATE_ZERO))            /* not zero */
>        return false;
>    }

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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