Libguestfs - Aug 2023 - [libnbd PATCH v4 17/25] info: Update nbdinfo --map to use 64-bit block status

Although we usually map "base:allocation" which doesn't require
the
use of the 64-bit API for flags, this application IS intended to map
out other metacontexts that might have 64-bit flags.  And when
extended headers are in use, we might as well ask for the server to
give us extents as large as it wants, rather than breaking things up
at 4G boundaries.

At the time this patch was written, there are no known servers that
actually provide a metacontext with 64-bit flags.  However, that is
planned for the nbdkit v3 protocol.

Signed-off-by: Eric Blake <eblake at redhat.com>
Reviewed-by: Richard W.M. Jones <rjones at redhat.com>
---

v4: no change
---
 info/map.c | 65 ++++++++++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 31 deletions(-)

diff --git a/info/map.c b/info/map.c
index 1169fce4..50b058f2 100644
--- a/info/map.c
+++ b/info/map.c
@@ -36,13 +36,13 @@

 #include "nbdinfo.h"

-DEFINE_VECTOR_TYPE (uint32_vector, uint32_t);
+DEFINE_VECTOR_TYPE (uint64_vector, uint64_t);

-static void print_extents (uint32_vector *entries);
-static void print_totals (uint32_vector *entries, int64_t size);
+static void print_extents (uint64_vector *entries);
+static void print_totals (uint64_vector *entries, int64_t size);
 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);

 void
@@ -50,7 +50,7 @@ do_map (void)
 {
   size_t i;
   int64_t size;
-  uint32_vector entries = empty_vector;
+  uint64_vector entries = empty_vector;
   uint64_t offset, align, max_len;
   size_t prev_entries_size;

@@ -69,14 +69,16 @@ do_map (void)
     fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
     exit (EXIT_FAILURE);
   }
+  if (nbd_get_extended_headers_negotiated (nbd) == 1)
+    max_len = size;

   for (offset = 0; offset < size;) {
     prev_entries_size = entries.len;
-    if (nbd_block_status (nbd, MIN (size - offset, max_len), offset,
-                          (nbd_extent_callback) {
-                            .callback = extent_callback,
-                            .user_data = &entries },
-                          0) == -1) {
+    if (nbd_block_status_64 (nbd, MIN (size - offset, max_len), offset,
+                             (nbd_extent64_callback) {
+                               .callback = extent_callback,
+                               .user_data = &entries },
+                             0) == -1) {
       fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
       exit (EXIT_FAILURE);
     }
@@ -99,18 +101,18 @@ do_map (void)
 }

 /* Callback handling --map. */
-static void print_one_extent (uint64_t offset, uint64_t len, uint32_t type);
-static void extent_description (const char *metacontext, uint32_t type,
+static void print_one_extent (uint64_t offset, uint64_t len, uint64_t type);
+static void extent_description (const char *metacontext, uint64_t type,
                                 char **descr, bool *free_descr,
                                 const char **fg, const char **bg);

 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, map) != 0)
@@ -120,7 +122,8 @@ extent_callback (void *user_data, const char *metacontext,
    * print_extents below.
    */
   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);
     }
@@ -129,7 +132,7 @@ extent_callback (void *user_data, const char *metacontext,
 }

 static void
-print_extents (uint32_vector *entries)
+print_extents (uint64_vector *entries)
 {
   size_t i, j;
   uint64_t offset = 0;          /* end of last extent printed + 1 */
@@ -138,7 +141,7 @@ print_extents (uint32_vector *entries)
   if (json_output) fprintf (fp, "[\n");

   for (i = 0; i < entries->len; i += 2) {
-    uint32_t type = entries->ptr[last+1];
+    uint64_t type = entries->ptr[last+1];

     /* If we're coalescing and the current type is different from the
      * previous one then we should print everything up to this entry.
@@ -157,7 +160,7 @@ print_extents (uint32_vector *entries)

   /* Print the last extent if there is one. */
   if (last != i) {
-    uint32_t type = entries->ptr[last+1];
+    uint64_t type = entries->ptr[last+1];
     uint64_t len;

     for (j = last, len = 0; j < i; j += 2)
@@ -169,7 +172,7 @@ print_extents (uint32_vector *entries)
 }

 static void
-print_one_extent (uint64_t offset, uint64_t len, uint32_t type)
+print_one_extent (uint64_t offset, uint64_t len, uint64_t type)
 {
   static bool comma = false;
   char *descr;
@@ -185,7 +188,7 @@ print_one_extent (uint64_t offset, uint64_t len, uint32_t
type)
       ansi_colour (bg, fp);
     fprintf (fp, "%10" PRIu64 "  "
              "%10" PRIu64 "  "
-             "%3" PRIu32,
+             "%3" PRIu64,
              offset, len, type);
     if (descr)
       fprintf (fp, "  %s", descr);
@@ -199,7 +202,7 @@ print_one_extent (uint64_t offset, uint64_t len, uint32_t
type)

     fprintf (fp, "{ \"offset\": %" PRIu64 ", "
              "\"length\": %" PRIu64 ", "
-             "\"type\": %" PRIu32,
+             "\"type\": %" PRIu64,
              offset, len, type);
     if (descr) {
       fprintf (fp, ", \"description\": ");
@@ -215,9 +218,9 @@ print_one_extent (uint64_t offset, uint64_t len, uint32_t
type)

 /* --map --totals suboption */
 static void
-print_totals (uint32_vector *entries, int64_t size)
+print_totals (uint64_vector *entries, int64_t size)
 {
-  uint32_t type;
+  uint64_t type;
   bool comma = false;

   /* This is necessary to avoid a divide by zero below, but if the
@@ -237,16 +240,16 @@ print_totals (uint32_vector *entries, int64_t size)
    */
   type = 0;
   for (;;) {
-    uint64_t next_type = (uint64_t)UINT32_MAX + 1;
+    uint64_t next_type = 0;
     uint64_t c = 0;
     size_t i;

     for (i = 0; i < entries->len; i += 2) {
-      uint32_t t = entries->ptr[i+1];
+      uint64_t t = entries->ptr[i+1];

       if (t == type)
         c += entries->ptr[i];
-      else if (type < t && t < next_type)
+      else if (type < t && (next_type == 0 || t < next_type))
         next_type = t;
     }

@@ -263,7 +266,7 @@ print_totals (uint32_vector *entries, int64_t size)
           ansi_colour (fg, fp);
         if (bg)
           ansi_colour (bg, fp);
-        fprintf (fp, "%10" PRIu64 " %5.1f%% %3" PRIu32,
+        fprintf (fp, "%10" PRIu64 " %5.1f%% %3" PRIu64,
                  c, percent, type);
         if (descr)
           fprintf (fp, " %s", descr);
@@ -278,7 +281,7 @@ print_totals (uint32_vector *entries, int64_t size)
         fprintf (fp,
                  "{ \"size\": %" PRIu64 ", "
                  "\"percent\": %g, "
-                 "\"type\": %" PRIu32,
+                 "\"type\": %" PRIu64,
                  c, percent, type);
         if (descr) {
           fprintf (fp, ", \"description\": ");
@@ -292,7 +295,7 @@ print_totals (uint32_vector *entries, int64_t size)
         free (descr);
     }

-    if (next_type == (uint64_t)UINT32_MAX + 1)
+    if (next_type == 0)
       break;
     type = next_type;
   }
@@ -301,7 +304,7 @@ print_totals (uint32_vector *entries, int64_t size)
 }

 static void
-extent_description (const char *metacontext, uint32_t type,
+extent_description (const char *metacontext, uint64_t type,
                     char **descr, bool *free_descr,
                     const char **fg, const char **bg)
 {
@@ -348,7 +351,7 @@ extent_description (const char *metacontext, uint32_t type,
       *fg = ANSI_FG_BRIGHT_WHITE; *bg = ANSI_BG_BLACK;
       return;
     default:
-      if (asprintf (descr, "backing depth %u", type) == -1) {
+      if (asprintf (descr, "backing depth %" PRIu64, type) == -1) {
         perror ("asprintf");
         exit (EXIT_FAILURE);
       }
-- 
2.41.0

On Wed, Aug 02, 2023 at 08:50:37PM -0500, Eric Blake
wrote:
> Although we usually map "base:allocation" which doesn't
require the
> use of the 64-bit API for flags, this application IS intended to map
> out other metacontexts that might have 64-bit flags.  And when
> extended headers are in use, we might as well ask for the server to
> give us extents as large as it wants, rather than breaking things up
> at 4G boundaries.
> 
> At the time this patch was written, there are no known servers that
> actually provide a metacontext with 64-bit flags.  However, that is
> planned for the nbdkit v3 protocol.
> 
> Signed-off-by: Eric Blake <eblake at redhat.com>
> Reviewed-by: Richard W.M. Jones <rjones at redhat.com>
> ---
> 
> v4: no change
> ---
>  info/map.c | 65 ++++++++++++++++++++++++++++--------------------------
>  1 file changed, 34 insertions(+), 31 deletions(-)
> 
> diff --git a/info/map.c b/info/map.c
> index 1169fce4..50b058f2 100644
> --- a/info/map.c
> +++ b/info/map.c
> @@ -36,13 +36,13 @@
> 
>  #include "nbdinfo.h"
> 
> -DEFINE_VECTOR_TYPE (uint32_vector, uint32_t);
> +DEFINE_VECTOR_TYPE (uint64_vector, uint64_t);
> 
> -static void print_extents (uint32_vector *entries);
> -static void print_totals (uint32_vector *entries, int64_t size);
> +static void print_extents (uint64_vector *entries);
> +static void print_totals (uint64_vector *entries, int64_t size);
>  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);
> 
>  void
> @@ -50,7 +50,7 @@ do_map (void)
>  {
>    size_t i;
>    int64_t size;
> -  uint32_vector entries = empty_vector;
> +  uint64_vector entries = empty_vector;
>    uint64_t offset, align, max_len;
>    size_t prev_entries_size;
> 
> @@ -69,14 +69,16 @@ do_map (void)
>      fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
>      exit (EXIT_FAILURE);
>    }
> +  if (nbd_get_extended_headers_negotiated (nbd) == 1)
> +    max_len = size;
> 
>    for (offset = 0; offset < size;) {
>      prev_entries_size = entries.len;
> -    if (nbd_block_status (nbd, MIN (size - offset, max_len), offset,
> -                          (nbd_extent_callback) {
> -                            .callback = extent_callback,
> -                            .user_data = &entries },
> -                          0) == -1) {
> +    if (nbd_block_status_64 (nbd, MIN (size - offset, max_len), offset,
> +                             (nbd_extent64_callback) {
> +                               .callback = extent_callback,
> +                               .user_data = &entries },
> +                             0) == -1) {
>        fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
>        exit (EXIT_FAILURE);
>      }
> @@ -99,18 +101,18 @@ do_map (void)
>  }
> 
>  /* Callback handling --map. */
> -static void print_one_extent (uint64_t offset, uint64_t len, uint32_t
type);
> -static void extent_description (const char *metacontext, uint32_t type,
> +static void print_one_extent (uint64_t offset, uint64_t len, uint64_t
type);
> +static void extent_description (const char *metacontext, uint64_t type,
>                                  char **descr, bool *free_descr,
>                                  const char **fg, const char **bg);
> 
>  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, map) != 0)
> @@ -120,7 +122,8 @@ extent_callback (void *user_data, const char
*metacontext,
>     * print_extents below.
>     */
>    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) {
I guess there's a case for making it save the nbd_extent here rather
than pretend that we're still collecting a flat array of pairs, but it
simplifies the changes later.  Maybe that's something we can do in
future.
>        perror ("realloc");
>        exit (EXIT_FAILURE);
>      }
> @@ -129,7 +132,7 @@ extent_callback (void *user_data, const char
*metacontext,
>  }
> 
>  static void
> -print_extents (uint32_vector *entries)
> +print_extents (uint64_vector *entries)
>  {
>    size_t i, j;
>    uint64_t offset = 0;          /* end of last extent printed + 1 */
> @@ -138,7 +141,7 @@ print_extents (uint32_vector *entries)
>    if (json_output) fprintf (fp, "[\n");
> 
>    for (i = 0; i < entries->len; i += 2) {
> -    uint32_t type = entries->ptr[last+1];
> +    uint64_t type = entries->ptr[last+1];
> 
>      /* If we're coalescing and the current type is different from the
>       * previous one then we should print everything up to this entry.
> @@ -157,7 +160,7 @@ print_extents (uint32_vector *entries)
> 
>    /* Print the last extent if there is one. */
>    if (last != i) {
> -    uint32_t type = entries->ptr[last+1];
> +    uint64_t type = entries->ptr[last+1];
>      uint64_t len;
> 
>      for (j = last, len = 0; j < i; j += 2)
> @@ -169,7 +172,7 @@ print_extents (uint32_vector *entries)
>  }
> 
>  static void
> -print_one_extent (uint64_t offset, uint64_t len, uint32_t type)
> +print_one_extent (uint64_t offset, uint64_t len, uint64_t type)
>  {
>    static bool comma = false;
>    char *descr;
> @@ -185,7 +188,7 @@ print_one_extent (uint64_t offset, uint64_t len,
uint32_t type)
>        ansi_colour (bg, fp);
>      fprintf (fp, "%10" PRIu64 "  "
>               "%10" PRIu64 "  "
> -             "%3" PRIu32,
> +             "%3" PRIu64,
>               offset, len, type);
>      if (descr)
>        fprintf (fp, "  %s", descr);
> @@ -199,7 +202,7 @@ print_one_extent (uint64_t offset, uint64_t len,
uint32_t type)
> 
>      fprintf (fp, "{ \"offset\": %" PRIu64 ",
"
>               "\"length\": %" PRIu64 ", "
> -             "\"type\": %" PRIu32,
> +             "\"type\": %" PRIu64,
>               offset, len, type);
>      if (descr) {
>        fprintf (fp, ", \"description\": ");
> @@ -215,9 +218,9 @@ print_one_extent (uint64_t offset, uint64_t len,
uint32_t type)
> 
>  /* --map --totals suboption */
>  static void
> -print_totals (uint32_vector *entries, int64_t size)
> +print_totals (uint64_vector *entries, int64_t size)
>  {
> -  uint32_t type;
> +  uint64_t type;
>    bool comma = false;
> 
>    /* This is necessary to avoid a divide by zero below, but if the
> @@ -237,16 +240,16 @@ print_totals (uint32_vector *entries, int64_t size)
>     */
>    type = 0;
>    for (;;) {
> -    uint64_t next_type = (uint64_t)UINT32_MAX + 1;
> +    uint64_t next_type = 0;
>      uint64_t c = 0;
>      size_t i;
> 
>      for (i = 0; i < entries->len; i += 2) {
> -      uint32_t t = entries->ptr[i+1];
> +      uint64_t t = entries->ptr[i+1];
> 
>        if (t == type)
>          c += entries->ptr[i];
> -      else if (type < t && t < next_type)
> +      else if (type < t && (next_type == 0 || t <
next_type))
>          next_type = t;
>      }
> 
> @@ -263,7 +266,7 @@ print_totals (uint32_vector *entries, int64_t size)
>            ansi_colour (fg, fp);
>          if (bg)
>            ansi_colour (bg, fp);
> -        fprintf (fp, "%10" PRIu64 " %5.1f%% %3"
PRIu32,
> +        fprintf (fp, "%10" PRIu64 " %5.1f%% %3"
PRIu64,
>                   c, percent, type);
>          if (descr)
>            fprintf (fp, " %s", descr);
> @@ -278,7 +281,7 @@ print_totals (uint32_vector *entries, int64_t size)
>          fprintf (fp,
>                   "{ \"size\": %" PRIu64 ", "
>                   "\"percent\": %g, "
> -                 "\"type\": %" PRIu32,
> +                 "\"type\": %" PRIu64,
>                   c, percent, type);
>          if (descr) {
>            fprintf (fp, ", \"description\": ");
> @@ -292,7 +295,7 @@ print_totals (uint32_vector *entries, int64_t size)
>          free (descr);
>      }
> 
> -    if (next_type == (uint64_t)UINT32_MAX + 1)
> +    if (next_type == 0)
>        break;
>      type = next_type;
>    }
> @@ -301,7 +304,7 @@ print_totals (uint32_vector *entries, int64_t size)
>  }
> 
>  static void
> -extent_description (const char *metacontext, uint32_t type,
> +extent_description (const char *metacontext, uint64_t type,
>                      char **descr, bool *free_descr,
>                      const char **fg, const char **bg)
>  {
> @@ -348,7 +351,7 @@ extent_description (const char *metacontext, uint32_t
type,
>        *fg = ANSI_FG_BRIGHT_WHITE; *bg = ANSI_BG_BLACK;
>        return;
>      default:
> -      if (asprintf (descr, "backing depth %u", type) == -1) {
> +      if (asprintf (descr, "backing depth %" PRIu64, type) ==
-1) {
>          perror ("asprintf");
>          exit (EXIT_FAILURE);
>        }
Previously reviewed, still good.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
nbdkit - Flexible, fast NBD server with plugins
https://gitlab.com/nbdkit/nbdkit