From 045649a2755e2a809559e8105ef7b39833886014 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 22 Nov 2024 08:28:04 -0800 Subject: [PATCH] logwrites: only use BLKDISCARD if we know discard zeroes data Building off the checks established in the previous patch, only enable the use of BLKDISCARD if we know that the logwrites device guarantees that reads after a discard return zeroes. Signed-off-by: "Darrick J. Wong" --- common/dmlogwrites | 10 ++++++++-- src/log-writes/replay-log.c | 8 ++++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/common/dmlogwrites b/common/dmlogwrites index 96101d53c..fbc8beb5c 100644 --- a/common/dmlogwrites +++ b/common/dmlogwrites @@ -81,7 +81,10 @@ _log_writes_check_bdev() test "$(cat "$sysfs/queue/discard_max_bytes")" -eq 0 && return # dm-thinp guarantees that reads after discards return zeroes - dmsetup status "$blkdev" 2>/dev/null | grep -q '^0.* thin ' && return + if dmsetup status "$blkdev" 2>/dev/null | grep -q '^0.* thin '; then + LOGWRITES_REPLAY_ARGS+=(--discard-zeroes-data) + return + fi echo "HINT: $blkdev doesn't guarantee that reads after DISCARD will return zeroes" >> $seqres.hints echo " This is required for correct journal replay on some filesystems (e.g. xfs)" >> $seqres.hints @@ -110,6 +113,7 @@ _log_writes_init() BLK_DEV_SIZE=$((length / blksz)) fi + LOGWRITES_REPLAY_ARGS=() LOGWRITES_NAME=logwrites-test LOGWRITES_DMDEV=/dev/mapper/$LOGWRITES_NAME LOGWRITES_TABLE="0 $BLK_DEV_SIZE log-writes $blkdev $LOGWRITES_DEV" @@ -161,7 +165,8 @@ _log_writes_replay_log() [ $? -ne 0 ] && _fail "mark '$_mark' does not exist" $here/src/log-writes/replay-log --log $LOGWRITES_DEV --replay $_blkdev \ - --end-mark $_mark >> $seqres.full 2>&1 + --end-mark $_mark "${LOGWRITES_REPLAY_ARGS[@]}" \ + >> $seqres.full 2>&1 [ $? -ne 0 ] && _fail "replay failed" } @@ -231,6 +236,7 @@ _log_writes_replay_log_range() echo "=== replay to $end ===" >> $seqres.full $here/src/log-writes/replay-log -vv --log $LOGWRITES_DEV \ --replay $blkdev --limit $(($end + 1)) \ + "${LOGWRITES_REPLAY_ARGS[@]}" \ >> $seqres.full 2>&1 [ $? -ne 0 ] && _fail "replay failed" } diff --git a/src/log-writes/replay-log.c b/src/log-writes/replay-log.c index 968c82ab6..e07401f63 100644 --- a/src/log-writes/replay-log.c +++ b/src/log-writes/replay-log.c @@ -18,6 +18,7 @@ enum option_indexes { FIND, NUM_ENTRIES, NO_DISCARD, + DISCARD_ZEROES_DATA, FSCK, CHECK, START_MARK, @@ -37,6 +38,7 @@ static struct option long_options[] = { {"find", no_argument, NULL, 0}, {"num-entries", no_argument, NULL, 0}, {"no-discard", no_argument, NULL, 0}, + {"discard-zeroes-data", no_argument, NULL, 0}, {"fsck", required_argument, NULL, 0}, {"check", required_argument, NULL, 0}, {"start-mark", required_argument, NULL, 0}, @@ -155,6 +157,7 @@ int main(int argc, char **argv) int ret; int print_num_entries = 0; int discard = 1; + int use_kernel_discard = 0; enum log_replay_check_mode check_mode = 0; while ((c = getopt_long(argc, argv, "v", long_options, @@ -242,6 +245,9 @@ int main(int argc, char **argv) case NO_DISCARD: discard = 0; break; + case DISCARD_ZEROES_DATA: + use_kernel_discard = 1; + break; case FSCK: fsck_command = strdup(optarg); if (!fsck_command) { @@ -299,6 +305,8 @@ int main(int argc, char **argv) if (!discard) log->flags |= LOG_IGNORE_DISCARD; + if (!use_kernel_discard) + log->flags |= LOG_DISCARD_NOT_SUPP; log->start_sector = start_sector; log->end_sector = end_sector; -- 2.49.0