[Xapian-tickets] [Xapian] #823: Unit test ioblock1 failure

[Xapian]

#823: Unit test ioblock1 failure
--------------------------+-------------------------------
 Reporter:  someplaceguy  |             Owner:  Olly Betts
     Type:  defect        |            Status:  assigned
 Priority:  normal        |         Milestone:  1.4.25
Component:  Test Suite    |           Version:  1.4.24
 Severity:  normal        |        Resolution:
 Keywords:                |        Blocked By:
 Blocking:                |  Operating System:  Linux
--------------------------+-------------------------------
Comment (by someplaceguy):

 Unfortunately, if I apply the latest patch, it results in the test being
 skipped.

 I enabled verbosity and added this debug patch:

 {{{#!diff
 diff --git a/tests/unittest.cc b/tests/unittest.cc
 index 8d5e2bb..837ef7f 100644
 --- a/tests/unittest.cc
 +++ b/tests/unittest.cc
 @@ -950,6 +951,7 @@ try {
          SKIP_TEST("Skipping rest of testcase - SEEK_HOLE failed");
      }
      if (hole >= statbuf.st_size) {
 +        printf("hole: %jd, st_size: %jd\n", (intmax_t) hole, (intmax_t)
 statbuf.st_size);
          close(fd);
          io_unlink(tmp_file);
          SKIP_TEST("Skipping rest of testcase - sparse files not
 supported");
 }}}

 Here's the result:
 {{{
 Running test: ioblock1...hole: 13312, st_size: 13312
  SKIPPED
 }}}

 Note that in ZFS, by default blocks are logically 128 KiB in size,
 although they can be compressed down to the block device's sector size
 (4096 bytes or 512 bytes, usually), or even 0 bytes if the block contains
 only zeros.

 So I believe what's happening is that the entire contents of the file are
 being stored in a single block, and that's why no hole can be seen.

 That said, note that users can configure ZFS filesystems to have a block
 size of (up to) 16 MiB currently. Furthermore, it's even possible to
 increase this limit by simply changing a kernel module parameter.
-- 
Ticket URL: <https://trac.xapian.org/ticket/823#comment:7>
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