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 https://opensource.org/licenses/CDDL-1.0. 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# Test that we can read from and write to a file in procfs whose contents is 32# backed by a linked list. 33# 34# STRATEGY: 35# 1. Take some snapshots of a filesystem, which will cause some messages to be 36# written to the zfs dbgmsgs. 37# 2. Read the dbgmsgs via procfs and verify that the expected messages are 38# present. 39# 3. Write to the dbgmsgs file to clear the messages. 40# 4. Read the dbgmsgs again, and make sure the messages are no longer present. 41# 42 43function cleanup 44{ 45 datasetexists $FS && destroy_dataset $FS -r 46} 47 48function count_snap_cmds 49{ 50 typeset expected_count=$1 51 count=$(grep -cE "command: (lt-)?zfs snapshot $FS@testsnapshot") 52 log_must [ "$count" -eq "$expected_count" ] 53} 54 55typeset -r ZFS_DBGMSG=/proc/spl/kstat/zfs/dbgmsg 56typeset -r FS=$TESTPOOL/fs 57typeset snap_msgs 58 59log_onexit cleanup 60 61# Clear out old messages 62echo 0 >$ZFS_DBGMSG || log_fail "failed to write to $ZFS_DBGMSG" 63 64log_must zfs create $FS 65for i in {1..20}; do 66 log_must zfs snapshot "$FS@testsnapshot$i" 67done 68sync_pool $TESTPOOL 69 70# 71# Read the debug message file in small chunks to make sure that the read is 72# split up into multiple syscalls. This tests that when a syscall begins we 73# correctly pick up in the list of messages where the previous syscall left 74# off. The size of the read can affect how many bytes the seq_file code has 75# left in its internal buffer, which in turn can affect the relative pos that 76# the seq_file code picks up at when the next read starts. Try a few 77# different size reads to make sure we can handle each case. 78# 79# Check that the file has the right contents by grepping for some of the 80# messages that we expect to be present. 81# 82for chunk_sz in {1,64,256,1024,4096}; do 83 dd if=$ZFS_DBGMSG bs=$chunk_sz | count_snap_cmds 20 84done 85 86# Clear out old messages and check that they really are gone 87echo 0 >$ZFS_DBGMSG || log_fail "failed to write to $ZFS_DBGMSG" 88count_snap_cmds 0 < $ZFS_DBGMSG 89# 90# Even though we don't expect any messages in the file, reading should still 91# succeed. 92# 93log_must cat $ZFS_DBGMSG 94 95log_pass "Basic reading/writing of procfs file backed by linked list successful" 96