tests/zfs-tests/tests/functional/procfs/procfs_list_concurrent_readers.ksh

   1 #!/bin/ksh -p
   2 #
   3 # CDDL HEADER START
   4 #
   5 # The contents of this file are subject to the terms of the
   6 # Common Development and Distribution License (the "License").
   7 # You may not use this file except in compliance with the License.
   8 #
   9 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10 # or http://www.opensolaris.org/os/licensing.
  11 # See the License for the specific language governing permissions
  12 # and limitations under the License.
  13 #
  14 # When distributing Covered Code, include this CDDL HEADER in each
  15 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16 # If applicable, add the following below this CDDL HEADER, with the
  17 # fields enclosed by brackets "[]" replaced with your own identifying
  18 # information: Portions Copyright [yyyy] [name of copyright owner]
  19 #
  20 # CDDL HEADER END
  21 #
  22
  23 #
  24 # Copyright (c) 2018 by Delphix. All rights reserved.
  25 #
  26
  27 . $STF_SUITE/include/libtest.shlib
  28
  29 #
  30 # DESCRIPTION:
  31 # Make sure that interleaving reads from different readers does not affect the
  32 # results that are returned.
  33 #
  34 # STRATEGY:
  35 # 1. Make sure a few debug messages have been logged.
  36 # 2. Open the procfs file and start reading from it.
  37 # 3. Open the file again, and read its entire contents.
  38 # 4. Resume reading from the first instance.
  39 # 5. Check that the contents read by the two instances are identical.
  40 #
  41
  42 function cleanup
  43 {
  44         [[ -z $msgs1 ]] || log_must rm $msgs1
  45         [[ -z $msgs2 ]] || log_must rm $msgs2
  46         datasetexists $FS && log_must zfs destroy -r $FS
  47 }
  48
  49 typeset -r ZFS_DBGMSG=/proc/spl/kstat/zfs/dbgmsg
  50 typeset -r FS=$TESTPOOL/fs
  51 typeset msgs1 msgs2
  52
  53 log_onexit cleanup
  54
  55 # Clear out old messages
  56 echo 0 >$ZFS_DBGMSG || log_fail "failed to write to $ZFS_DBGMSG"
  57
  58 # Add some new messages
  59 log_must zfs create $FS
  60 for i in {1..20}; do
  61         log_must zfs snapshot "$FS@testsnapshot$i"
  62 done
  63 log_must zpool sync $TESTPOOL
  64
  65 msgs1=$(mktemp) || log_fail
  66 msgs2=$(mktemp) || log_fail
  67
  68 #
  69 # Start reading file, pause and read it from another process, and then finish
  70 # reading.
  71 #
  72 { dd bs=512 count=4; cat $ZFS_DBGMSG >$msgs1; cat; } <$ZFS_DBGMSG >$msgs2
  73
  74 #
  75 # Truncate the result of the read that completed second in case it picked up an
  76 # extra message that was logged after the first read completed.
  77 #
  78 log_must truncate -s $(stat -c "%s" $msgs1) $msgs2
  79
  80 log_must diff $msgs1 $msgs2
  81
  82 log_pass "Concurrent readers receive identical results"