| #!/bin/ksh -p |
| # |
| # CDDL HEADER START |
| # |
| # The contents of this file are subject to the terms of the |
| # Common Development and Distribution License (the "License"). |
| # You may not use this file except in compliance with the License. |
| # |
| # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| # or http://www.opensolaris.org/os/licensing. |
| # See the License for the specific language governing permissions |
| # and limitations under the License. |
| # |
| # When distributing Covered Code, include this CDDL HEADER in each |
| # file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| # If applicable, add the following below this CDDL HEADER, with the |
| # fields enclosed by brackets "[]" replaced with your own identifying |
| # information: Portions Copyright [yyyy] [name of copyright owner] |
| # |
| # CDDL HEADER END |
| # |
| |
| # |
| # Copyright (c) 2018 by Delphix. All rights reserved. |
| # |
| |
| . $STF_SUITE/include/libtest.shlib |
| |
| # |
| # DESCRIPTION: |
| # Test that we can read from and write to a file in procfs whose contents is |
| # backed by a linked list. |
| # |
| # STRATEGY: |
| # 1. Take some snapshots of a filesystem, which will cause some messages to be |
| # written to the zfs dbgmsgs. |
| # 2. Read the dbgmsgs via procfs and verify that the expected messages are |
| # present. |
| # 3. Write to the dbgmsgs file to clear the messages. |
| # 4. Read the dbgmsgs again, and make sure the messages are no longer present. |
| # |
| |
| function cleanup |
| { |
| datasetexists $FS && destroy_dataset $FS -r |
| } |
| |
| function count_snap_cmds |
| { |
| typeset expected_count=$1 |
| count=$(grep -E "command: (lt-)?zfs snapshot $FS@testsnapshot" | wc -l) |
| log_must eval "[[ $count -eq $expected_count ]]" |
| } |
| |
| typeset -r ZFS_DBGMSG=/proc/spl/kstat/zfs/dbgmsg |
| typeset -r FS=$TESTPOOL/fs |
| typeset snap_msgs |
| |
| log_onexit cleanup |
| |
| # Clear out old messages |
| echo 0 >$ZFS_DBGMSG || log_fail "failed to write to $ZFS_DBGMSG" |
| |
| log_must zfs create $FS |
| for i in {1..20}; do |
| log_must zfs snapshot "$FS@testsnapshot$i" |
| done |
| log_must zpool sync $TESTPOOL |
| |
| # |
| # Read the debug message file in small chunks to make sure that the read is |
| # split up into multiple syscalls. This tests that when a syscall begins we |
| # correctly pick up in the list of messages where the previous syscall left |
| # off. The size of the read can affect how many bytes the seq_file code has |
| # left in its internal buffer, which in turn can affect the relative pos that |
| # the seq_file code picks up at when the next read starts. Try a few |
| # different size reads to make sure we can handle each case. |
| # |
| # Check that the file has the right contents by grepping for some of the |
| # messages that we expect to be present. |
| # |
| for chunk_sz in {1,64,256,1024,4096}; do |
| dd if=$ZFS_DBGMSG bs=$chunk_sz | count_snap_cmds 20 |
| done |
| |
| # Clear out old messages and check that they really are gone |
| echo 0 >$ZFS_DBGMSG || log_fail "failed to write to $ZFS_DBGMSG" |
| cat $ZFS_DBGMSG | count_snap_cmds 0 |
| # |
| # Even though we don't expect any messages in the file, reading should still |
| # succeed. |
| # |
| log_must cat $ZFS_DBGMSG |
| |
| log_pass "Basic reading/writing of procfs file backed by linked list successful" |