MDEV-28250 aix test case failure innodb_zip.innochecksum_3,4k,crc32,i…

…nnodb

As discovered by tracing, but also presenting in AIX fseeko
documentation, seeking beyond the EOF is acceptable, as you can write
there.

To display the same error in AIX to other implementations that return
errors on seek, we take the EFBIG error code on reading and error the
same way.

An AIX truss of an aspect of the test:

truss extra/innochecksum --page=18446744073709551615 $MYSQLD_DATADIR/test/tab1.ibd

  statx("./mysql-test/var/log/innodb_zip.innochecksum_3-4k,crc32,innodb/mysqld.1/data//test/tab1.ibd", 0x0FFFFFFFFFFFF610, 176, 010) = 0
  kopen("./mysql-test/var/log/innodb_zip.innochecksum_3-4k,crc32,innodb/mysqld.1/data//test/tab1.ibd", O_RDONLY|O_LARGEFILE) = 3
  kfcntl(3, 12, 0x00000001100006C8)               = 0
  kfcntl(3, F_GETFL, 0x00000001100A6CF8)          = 67108864
  kioctl(3, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
  klseek(3, 0, 1, 0x0FFFFFFFFFFFF3F0)             = 0
  kioctl(3, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
  kread(3, "DEADBEEF\0\0\0\0FFFFFFFF".., 4096)    = 4096
  klseek(3, 0, 1, 0x0FFFFFFFFFFFF450)             = 0
  klseek(3, 17592186040320, 0, 0x0FFFFFFFFFFFF450) = 0
  klseek(3, 0, 1, 0x0FFFFFFFFFFFF3F0)             = 0
  kread(3, "DEADBEEF\0\0\0\0FFFFFFFF".., 4096)    Err#27 EFBIG

An equivalent Linux trace:

ltrace extra/innochecksum --page=18446744073709551615 $MYSQLD_DATADIR/test/tab1.ibd

  stat64(0x7fff10ea2dc3, 0x7fff10ea0670, 88, 0x8026be41)         = 0
  open64("./mysql-test/var/log/innodb_zip."..., 0, 02072403160)  = 3
  fcntl64(3, 6, 0x139f180, 1)                                    = 0
  fgetpos64(0x615000000080, 0x7fff10ea0760, 1, 0)                = 0
  fseeko64(0x615000000080, 0xffffffff000, 0, 5 <unfinished ...>
  pthread_getspecific(0, 0x4d0eb8, 0x7fff10ea0490, 0)            = 0x7f7b2806d000
  <... fseeko64 resumed> )                                       = 0
  fgetpos64(0x615000000080, 0x7fff10ea0760, 1, 1)                = 0
  feof(0x615000000080)                                           = 0
  feof(0x615000000080)                                           = 1
  Error: Unable to seek to necessary offset

extra/innochecksum.cc

@@ -1893,6 +1893,18 @@ int main(
 			}
 
 			if (ferror(fil_in)) {
+#ifdef _AIX
+				/*
+				  AIX fseeko can go past eof without error.
+				  the error occurs on read, hence output the
+				  same error here as would show up on other
+				  platforms. This shows up in the mtr test
+				  innodb_zip.innochecksum_3-4k,crc32,innodb
+				*/
+				if (errno == EFBIG) {
+					goto unexpected_eof;
+				}
+#endif
 				fprintf(stderr, "Error reading " ULINTPF " bytes",
 					physical_page_size);
 				perror(" ");