Fix L2ARC reads when compressed ARC disabled
When reading compressed blocks from the L2ARC, with compressed ARC disabled, arc_hdr_size() returns LSIZE rather than PSIZE, but the actual read is PSIZE. This causes l2arc_read_done() to compare the checksum against the wrong size, resulting in checksum failure. This manifests as an increase in the kstat l2_cksum_bad and the read being retried from the main pool, making the L2ARC ineffective. Add new L2ARC tests with Compressed ARC enabled/disabled Blocks are handled differently depending on the state of the zfs_compressed_arc_enabled tunable. If a block is compressed on-disk, and compressed_arc is enabled: - the block is read from disk - It is NOT decompressed - It is added to the ARC in its compressed form - l2arc_write_buffers() may write it to the L2ARC (as is) - l2arc_read_done() compares the checksum to the BP (compressed) However, if compressed_arc is disabled: - the block is read from disk - It is decompressed - It is added to the ARC (uncompressed) - l2arc_write_buffers() will use l2arc_apply_transforms() to recompress the block, before writing it to the L2ARC - l2arc_read_done() compares the checksum to the BP (compressed) - l2arc_read_done() will use l2arc_untransform() to uncompress it This test writes out a test file to a pool consisting of one disk and one cache device, then randomly reads from it. Since the arc_max in the tests is low, this will feed the L2ARC, and result in reads from the L2ARC. We compare the value of the kstat l2_cksum_bad before and after to determine if any blocks failed to survive the trip through the L2ARC. Sponsored-by: The FreeBSD Foundation Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Allan Jude <allanjude@freebsd.org> Closes #10693
This commit is contained in:
Allan Jude
GitHub
parent
faa296c73c
commit
fc34dfba8e
|
|
@ -26,6 +26,10 @@
|
|||
* Copyright (c) 2017, Nexenta Systems, Inc. All rights reserved.
|
||||
* Copyright (c) 2019, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
|
||||
* Copyright (c) 2020, George Amanakis. All rights reserved.
|
||||
* Copyright (c) 2020, The FreeBSD Foundation [1]
|
||||
*
|
||||
* [1] Portions of this software were developed by Allan Jude
|
||||
* under sponsorship from the FreeBSD Foundation.
|
||||
*/
|
||||
|
||||
/*
|
||||
|
|
@ -6152,6 +6156,17 @@ top:
|
|||
cb->l2rcb_zb = *zb;
|
||||
cb->l2rcb_flags = zio_flags;
|
||||
|
||||
/*
|
||||
* When Compressed ARC is disabled, but the
|
||||
* L2ARC block is compressed, arc_hdr_size()
|
||||
* will have returned LSIZE rather than PSIZE.
|
||||
*/
|
||||
if (HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF &&
|
||||
!HDR_COMPRESSION_ENABLED(hdr) &&
|
||||
HDR_GET_PSIZE(hdr) != 0) {
|
||||
size = HDR_GET_PSIZE(hdr);
|
||||
}
|
||||
|
||||
asize = vdev_psize_to_asize(vd, size);
|
||||
if (asize != size) {
|
||||
abd = abd_alloc_for_io(asize,
|
||||
|
|
|
|||
|
|
@ -536,7 +536,8 @@ user =
|
|||
tags = ['functional', 'cli_user', 'zpool_status']
|
||||
|
||||
[tests/functional/compression]
|
||||
tests = ['compress_001_pos', 'compress_002_pos', 'compress_003_pos']
|
||||
tests = ['compress_001_pos', 'compress_002_pos', 'compress_003_pos',
|
||||
'l2arc_compressed_arc', 'l2arc_compressed_arc_disabled']
|
||||
tags = ['functional', 'compression']
|
||||
|
||||
[tests/functional/cp_files]
|
||||
|
|
|
|||
|
|
@ -5,7 +5,9 @@ dist_pkgdata_SCRIPTS = \
|
|||
compress_001_pos.ksh \
|
||||
compress_002_pos.ksh \
|
||||
compress_003_pos.ksh \
|
||||
compress_004_pos.ksh
|
||||
compress_004_pos.ksh \
|
||||
l2arc_compressed_arc.ksh \
|
||||
l2arc_compressed_arc_disabled.ksh
|
||||
|
||||
dist_pkgdata_DATA = \
|
||||
compress.cfg
|
||||
|
|
|
|||
|
|
@ -0,0 +1,97 @@
|
|||
#!/bin/ksh -p
|
||||
#
|
||||
# CDDL HEADER START
|
||||
#
|
||||
# This file and its contents are supplied under the terms of the
|
||||
# Common Development and Distribution License ("CDDL"), version 1.0.
|
||||
# You may only use this file in accordance with the terms of version
|
||||
# 1.0 of the CDDL.
|
||||
#
|
||||
# A full copy of the text of the CDDL should have accompanied this
|
||||
# source. A copy of the CDDL is also available via the Internet at
|
||||
# http://www.illumos.org/license/CDDL.
|
||||
#
|
||||
# CDDL HEADER END
|
||||
#
|
||||
|
||||
#
|
||||
# Copyright (c) 2020 The FreeBSD Foundation [1]
|
||||
#
|
||||
# [1] Portions of this software were developed by Allan Jude
|
||||
# under sponsorship from the FreeBSD Foundation.
|
||||
|
||||
. $STF_SUITE/include/libtest.shlib
|
||||
|
||||
export SIZE=1G
|
||||
export VDIR=$TESTDIR/disk.persist_l2arc
|
||||
export VDEV="$VDIR/a"
|
||||
export VDEV_CACHE="$VDIR/b"
|
||||
|
||||
# fio options
|
||||
export DIRECTORY=/$TESTPOOL-l2arc
|
||||
export NUMJOBS=4
|
||||
export RUNTIME=30
|
||||
export PERF_RANDSEED=1234
|
||||
export PERF_COMPPERCENT=66
|
||||
export PERF_COMPCHUNK=0
|
||||
export BLOCKSIZE=128K
|
||||
export SYNC_TYPE=0
|
||||
export DIRECT=1
|
||||
|
||||
#
|
||||
# DESCRIPTION:
|
||||
# System with compressed_arc disabled succeeds at reading from L2ARC
|
||||
#
|
||||
# STRATEGY:
|
||||
# 1. Enable compressed_arc.
|
||||
# 2. Create pool with a cache device and compression enabled.
|
||||
# 3. Read the number of L2ARC checksum failures.
|
||||
# 4. Create a random file in that pool and random read for 30 sec.
|
||||
# 5. Read the number of L2ARC checksum failures.
|
||||
#
|
||||
|
||||
verify_runnable "global"
|
||||
|
||||
log_assert "L2ARC with compressed_arc enabled succeeds."
|
||||
|
||||
origin_carc_setting=$(get_tunable COMPRESSED_ARC_ENABLED)
|
||||
|
||||
function cleanup
|
||||
{
|
||||
if poolexists $TESTPOOL-l2arc ; then
|
||||
destroy_pool $TESTPOOL-l2arc
|
||||
fi
|
||||
|
||||
log_must set_tunable64 COMPRESSED_ARC_ENABLED $origin_carc_setting
|
||||
}
|
||||
log_onexit cleanup
|
||||
|
||||
# Enable Compressed ARC so that in-ARC and on-disk will match
|
||||
log_must set_tunable64 COMPRESSED_ARC_ENABLED 1
|
||||
|
||||
log_must rm -rf $VDIR
|
||||
log_must mkdir -p $VDIR
|
||||
log_must mkfile $SIZE $VDEV
|
||||
|
||||
typeset fill_mb=800
|
||||
typeset cache_sz=$(( floor($fill_mb / 2) ))
|
||||
export FILE_SIZE=$(( floor($fill_mb / $NUMJOBS) ))M
|
||||
|
||||
log_must truncate -s ${cache_sz}M $VDEV_CACHE
|
||||
|
||||
log_must zpool create -O compression=lz4 -f $TESTPOOL-l2arc $VDEV cache $VDEV_CACHE
|
||||
|
||||
l2_cksum_bad_start=$(get_arcstat l2_cksum_bad)
|
||||
|
||||
log_must fio $FIO_SCRIPTS/mkfiles.fio
|
||||
log_must fio $FIO_SCRIPTS/random_reads.fio
|
||||
|
||||
l2_cksum_bad_end=$(get_arcstat l2_cksum_bad)
|
||||
|
||||
log_note "L2ARC Failed Checksums before: $l2_cksum_bad_start After:"\
|
||||
"$l2_cksum_bad_end"
|
||||
log_must test $(( $l2_cksum_bad_end - $l2_cksum_bad_start )) -eq 0
|
||||
|
||||
log_must zpool destroy -f $TESTPOOL-l2arc
|
||||
|
||||
log_pass "L2ARC with compressed_arc enabled does not result in checksum errors."
|
||||
|
|
@ -0,0 +1,98 @@
|
|||
#!/bin/ksh -p
|
||||
#
|
||||
# CDDL HEADER START
|
||||
#
|
||||
# This file and its contents are supplied under the terms of the
|
||||
# Common Development and Distribution License ("CDDL"), version 1.0.
|
||||
# You may only use this file in accordance with the terms of version
|
||||
# 1.0 of the CDDL.
|
||||
#
|
||||
# A full copy of the text of the CDDL should have accompanied this
|
||||
# source. A copy of the CDDL is also available via the Internet at
|
||||
# http://www.illumos.org/license/CDDL.
|
||||
#
|
||||
# CDDL HEADER END
|
||||
#
|
||||
|
||||
#
|
||||
# Copyright (c) 2020 The FreeBSD Foundation [1]
|
||||
#
|
||||
# [1] Portions of this software were developed by Allan Jude
|
||||
# under sponsorship from the FreeBSD Foundation.
|
||||
|
||||
. $STF_SUITE/include/libtest.shlib
|
||||
|
||||
export SIZE=1G
|
||||
export VDIR=$TESTDIR/disk.persist_l2arc
|
||||
export VDEV="$VDIR/a"
|
||||
export VDEV_CACHE="$VDIR/b"
|
||||
|
||||
# fio options
|
||||
export DIRECTORY=/$TESTPOOL-l2arc
|
||||
export NUMJOBS=4
|
||||
export RUNTIME=30
|
||||
export PERF_RANDSEED=1234
|
||||
export PERF_COMPPERCENT=66
|
||||
export PERF_COMPCHUNK=0
|
||||
export BLOCKSIZE=128K
|
||||
export SYNC_TYPE=0
|
||||
export DIRECT=1
|
||||
|
||||
#
|
||||
# DESCRIPTION:
|
||||
# System with compressed_arc disabled succeeds at reading from L2ARC
|
||||
#
|
||||
# STRATEGY:
|
||||
# 1. Disable compressed_arc.
|
||||
# 2. Create pool with a cache device and compression enabled.
|
||||
# 3. Read the number of L2ARC checksum failures.
|
||||
# 4. Create a random file in that pool and random read for 30 sec.
|
||||
# 5. Read the number of L2ARC checksum failures.
|
||||
#
|
||||
|
||||
verify_runnable "global"
|
||||
|
||||
log_assert "L2ARC with compressed_arc disabled succeeds."
|
||||
|
||||
origin_carc_setting=$(get_tunable COMPRESSED_ARC_ENABLED)
|
||||
|
||||
function cleanup
|
||||
{
|
||||
if poolexists $TESTPOOL-l2arc ; then
|
||||
destroy_pool $TESTPOOL-l2arc
|
||||
fi
|
||||
|
||||
log_must set_tunable64 COMPRESSED_ARC_ENABLED $origin_carc_setting
|
||||
}
|
||||
log_onexit cleanup
|
||||
|
||||
log_must rm -rf $VDIR
|
||||
log_must mkdir -p $VDIR
|
||||
log_must mkfile $SIZE $VDEV
|
||||
|
||||
# Disable Compressed ARC so that in-ARC and on-disk will not match
|
||||
log_must set_tunable64 COMPRESSED_ARC_ENABLED 0
|
||||
|
||||
typeset fill_mb=800
|
||||
typeset cache_sz=$(( floor($fill_mb / 2) ))
|
||||
export FILE_SIZE=$(( floor($fill_mb / $NUMJOBS) ))M
|
||||
|
||||
log_must truncate -s ${cache_sz}M $VDEV_CACHE
|
||||
|
||||
log_must zpool create -O compression=lz4 -f $TESTPOOL-l2arc $VDEV cache $VDEV_CACHE
|
||||
|
||||
l2_cksum_bad_start=$(get_arcstat l2_cksum_bad)
|
||||
|
||||
log_must fio $FIO_SCRIPTS/mkfiles.fio
|
||||
log_must fio $FIO_SCRIPTS/random_reads.fio
|
||||
|
||||
l2_cksum_bad_end=$(get_arcstat l2_cksum_bad)
|
||||
|
||||
log_note "L2ARC Failed Checksums before: $l2_cksum_bad_start After:"\
|
||||
"$l2_cksum_bad_end"
|
||||
log_must test $(( $l2_cksum_bad_end - $l2_cksum_bad_start )) -eq 0
|
||||
|
||||
log_must zpool destroy -f $TESTPOOL-l2arc
|
||||
|
||||
log_pass "L2ARC with compressed_arc disabled does not result in checksum"\
|
||||
"errors."
|
||||
Loading…
Reference in New Issue