interop/dirty-bitmap.c

   1 /* NBD client library in userspace
   2  * Copyright Red Hat
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 /* Test reading qemu dirty bitmap. */
  20
  21 #include <config.h>
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <assert.h>
  28 #include <stdbool.h>
  29 #include <errno.h>
  30
  31 #include <libnbd.h>
  32
  33 static const char *bitmap;
  34
  35 struct data {
  36   bool req_one;    /* input: true if req_one was passed to request */
  37   int count;       /* input: count of expected remaining calls */
  38   bool fail;       /* input: true to return failure */
  39   bool seen_base;  /* output: true if base:allocation encountered */
  40   bool seen_dirty; /* output: true if qemu:dirty-bitmap encountered */
  41 };
  42
  43 static int
  44 cb (void *opaque, const char *metacontext, uint64_t offset,
  45     uint32_t *entries, size_t len, int *error)
  46 {
  47   struct data *data = opaque;
  48
  49   /* libnbd does not actually verify that a server is fully compliant
  50    * to the spec; the asserts marked [qemu-nbd] are thus dependent on
  51    * the fact that qemu-nbd is compliant.  Furthermore, qemu 5.2 and
  52    * 6.0 disagree on whether base:allocation includes the hole bit for
  53    * the zeroes at 512k (both answers are compliant); but we care more
  54    * that the zeroes show up in the dirty bitmap
  55    */
  56   assert (offset == 0);
  57   assert (!*error || (data->fail && data->count == 1 && *error == EPROTO));
  58   assert (data->count-- > 0); /* [qemu-nbd] */
  59
  60   if (strcmp (metacontext, LIBNBD_CONTEXT_BASE_ALLOCATION) == 0) {
  61     assert (!data->seen_base); /* [qemu-nbd] */
  62     data->seen_base = true;
  63     if (data->req_one)
  64       assert (len == 2); /* [qemu-nbd] */
  65     else
  66       assert ((len & 1) == 0 && len > 2); /* [qemu-nbd] */
  67
  68     /* Data block offset 0 size 128k */
  69     assert (entries[0] == 131072); assert (entries[1] == 0);
  70     if (!data->req_one) {
  71       if (len == 4) {
  72         /* hole|zero offset 128k size 896k */
  73         assert (entries[2] == 917504);
  74         assert (entries[3] == (LIBNBD_STATE_HOLE|
  75                                LIBNBD_STATE_ZERO));
  76       }
  77       else {
  78         assert (len == 8);
  79         /* hole|zero offset 128k size 384k */
  80         assert (entries[2] == 393216);
  81         assert (entries[3] == (LIBNBD_STATE_HOLE|
  82                                LIBNBD_STATE_ZERO));
  83         /* allocated zero offset 512k size 64k */
  84         assert (entries[4] ==  65536);
  85         assert (entries[5] == LIBNBD_STATE_ZERO);
  86         /* hole|zero offset 576k size 448k */
  87         assert (entries[6] == 458752);
  88         assert (entries[7] == (LIBNBD_STATE_HOLE|
  89                                LIBNBD_STATE_ZERO));
  90       }
  91     }
  92   }
  93   else if (strcmp (metacontext, bitmap) == 0) {
  94     assert (!data->seen_dirty); /* [qemu-nbd] */
  95     data->seen_dirty = true;
  96     assert (len == (data->req_one ? 2 : 10)); /* [qemu-nbd] */
  97
  98     assert (entries[0] ==  65536); assert (entries[1] == 0);
  99     if (!data->req_one) {
 100       /* dirty block offset 64K size 64K */
 101       assert (entries[2] ==  65536); assert (entries[3] == 1);
 102       assert (entries[4] == 393216); assert (entries[5] == 0);
 103       /* dirty block offset 512K size 64K */
 104       assert (entries[6] ==  65536); assert (entries[7] == 1);
 105       assert (entries[8] == 458752); assert (entries[9] == 0);
 106     }
 107   }
 108   else {
 109     fprintf (stderr, "unexpected context %s\n", metacontext);
 110     exit (EXIT_FAILURE);
 111   }
 112
 113   if (data->fail) {
 114     /* Something NBD servers can't send */
 115     *error = data->count == 1 ? EPROTO : ECONNREFUSED;
 116     return -1;
 117   }
 118   return 0;
 119 }
 120
 121 int
 122 main (int argc, char *argv[])
 123 {
 124   struct nbd_handle *nbd;
 125   int64_t exportsize;
 126   struct data data;
 127   char c;
 128
 129   if (argc < 3) {
 130     fprintf (stderr, "%s bitmap qemu-nbd [args ...]\n", argv[0]);
 131     exit (EXIT_FAILURE);
 132   }
 133   bitmap = argv[1];
 134
 135   nbd = nbd_create ();
 136   if (nbd == NULL) {
 137     fprintf (stderr, "%s\n", nbd_get_error ());
 138     exit (EXIT_FAILURE);
 139   }
 140
 141   nbd_add_meta_context (nbd, LIBNBD_CONTEXT_BASE_ALLOCATION);
 142   nbd_add_meta_context (nbd, bitmap);
 143
 144   if (nbd_connect_systemd_socket_activation (nbd, &argv[2]) == -1) {
 145     fprintf (stderr, "%s\n", nbd_get_error ());
 146     exit (EXIT_FAILURE);
 147   }
 148
 149   exportsize = nbd_get_size (nbd);
 150   if (exportsize == -1) {
 151     fprintf (stderr, "%s\n", nbd_get_error ());
 152     exit (EXIT_FAILURE);
 153   }
 154
 155   data = (struct data) { .count = 2, };
 156   if (nbd_block_status (nbd, exportsize, 0,
 157                         (nbd_extent_callback) { .callback = cb, .user_data = &data },
 158                         0) == -1) {
 159     fprintf (stderr, "%s\n", nbd_get_error ());
 160     exit (EXIT_FAILURE);
 161   }
 162   assert (data.seen_base && data.seen_dirty);
 163
 164   data = (struct data) { .req_one = true, .count = 2, };
 165   if (nbd_block_status (nbd, exportsize, 0,
 166                         (nbd_extent_callback) { .callback = cb, .user_data = &data },
 167                         LIBNBD_CMD_FLAG_REQ_ONE) == -1) {
 168     fprintf (stderr, "%s\n", nbd_get_error ());
 169     exit (EXIT_FAILURE);
 170   }
 171   assert (data.seen_base && data.seen_dirty);
 172
 173   /* Trigger a failed callback, to prove connection stays up. */
 174   data = (struct data) { .count = 2, .fail = true, };
 175   if (nbd_block_status (nbd, exportsize, 0,
 176                         (nbd_extent_callback) { .callback = cb, .user_data = &data },
 177                         0) != -1) {
 178     fprintf (stderr, "unexpected block status success\n");
 179     exit (EXIT_FAILURE);
 180   }
 181   assert (nbd_get_errno () == EPROTO && nbd_aio_is_ready (nbd));
 182   assert (data.seen_base && data.seen_dirty);
 183
 184   if (nbd_pread (nbd, &c, 1, 0, 0) == -1) {
 185     fprintf (stderr, "%s\n", nbd_get_error ());
 186     exit (EXIT_FAILURE);
 187   }
 188
 189   if (nbd_shutdown (nbd, 0) == -1) {
 190     fprintf (stderr, "%s\n", nbd_get_error ());
 191     exit (EXIT_FAILURE);
 192   }
 193
 194   nbd_close (nbd);
 195
 196   exit (EXIT_SUCCESS);
 197 }