def start_monitoring(core_dev, cache_dev, cas_dev):
blktrace_core_dev = BlkTrace(core_dev, BlkTraceMask.discard)
blktrace_cache_dev = BlkTrace(cache_dev, BlkTraceMask.discard)
blktrace_cas = BlkTrace(cas_dev, BlkTraceMask.discard)
blktrace_core_dev.start_monitoring()
blktrace_cache_dev.start_monitoring()
blktrace_cas.start_monitoring()
return {
"core": blktrace_core_dev,
"cache": blktrace_cache_dev,
"cas": blktrace_cas
}
def test_trim_start_discard():
"""
title: Check discarding cache device at cache start
description: |
Create 2 partitions on trim-supporting device, write pattern to both partitions,
start blktrace against first one, start cache on first partition and check if discard
requests were sent at all and only to the first partition.
pass_criteria:
- Partition used for cache is discarded.
- Second partition is untouched - written pattern is preserved.
"""
with TestRun.step("Clearing dmesg"):
TestRun.executor.run_expect_success("dmesg -C")
with TestRun.step("Preparing cache device"):
dev = TestRun.disks['cache']
dev.create_partitions(
[Size(500, Unit.MebiByte),
Size(500, Unit.MebiByte)])
cas_part = dev.partitions[0]
non_cas_part = dev.partitions[1]
with TestRun.step("Writing different pattern on partitions"):
cas_fio = write_pattern(cas_part.path)
non_cas_fio = write_pattern(non_cas_part.path)
cas_fio.run()
non_cas_fio.run()
# TODO add blktracing for non-cas part
with TestRun.step("Starting blktrace against first (cache) partition"):
blktrace = BlkTrace(cas_part, BlkTraceMask.discard)
blktrace.start_monitoring()
with TestRun.step("Starting cache"):
cache = casadm.start_cache(cas_part, force=True)
metadata_size = get_metadata_size_from_dmesg()
with TestRun.step(
"Stop blktrace and check if discard requests were issued"):
cache_reqs = blktrace.stop_monitoring()
cache_part_start = cas_part.begin
# CAS should discard cache device during cache start
if len(cache_reqs) == 0:
TestRun.fail("No discard requests issued to the cas partition!")
non_meta_sector = (cache_part_start + metadata_size).get_value(
Unit.Blocks512)
non_meta_size = (cas_part.size - metadata_size).get_value(Unit.Byte)
for req in cache_reqs:
if req.sector_number != non_meta_sector:
TestRun.fail(
f"Discard request issued to wrong sector: {req.sector_number}, "
f"expected: {non_meta_sector}")
if req.byte_count != non_meta_size:
TestRun.fail(
f"Discard request issued with wrong bytes count: {req.byte_count}, "
f"expected: {non_meta_size} bytes")
cas_fio.read_write(ReadWrite.read)
non_cas_fio.read_write(ReadWrite.read)
cas_fio.verification_with_pattern("0x00")
cas_fio.offset(metadata_size)
cas_fio.run()
non_cas_fio.run()
with TestRun.step("Stopping cache"):
cache.stop()
