Kernel Block Layer Tests
blktests is a test suite for Linux;reg; kernel storage stack, that is, the block I/O layer as well as underlying device specific layers (SCSI, NVMe, SRP, etc). blktests is heavily inspired by the xfstests framework for testing file systems.
Recent contributions to blktests added zoned block device tests support.
The blktests project is hosted on GitHub.
Overview
blktests organizes test cases into groups. The test groups currently available are as shown in the table below.
| Group name | Description |
|---|---|
| block | Block layer generic tests |
| loop | Loopback device tests |
| meta | blktests self tests |
| nbd | Network block device driver tests |
| nvme | NVMe driver tests |
| nvmeof-mp | NVME-over-fabrics multipath tests |
| scsi | SCSI layer tests |
| srp | SCSI RDMA Protocol driver tests |
| zbd | Zoned block device tests |
The test groups supporting zoned block devices are block and zbd. blkzone and fio version 3.9 or higher must be installed for executing these test groups.
Configuration
Detailed generic information on how to configure and run blktests is provided here.
For executing tests against a physical zoned block device (e.g. a ZBC/ZAC disk),
the following config file should be prepared and copied to the blktests
installation directory. Tests can also be executed directly from the source
directory if the config file is copied in that location.
# Tests target device list
TEST_DEVS=(/dev/sdd)
# Enable zoned block device mode for the block group genertic tests
RUN_ZONED_TESTS=1
With this configuration, all tests relevant to zoned block devices will be
executed. The execution duration can be several 10s of minutes depending on the
target device and host system. To Shorten execution, the options TIMEOUT and
QUICK_RUN can be added to the configuration.
# Tests target device list
TEST_DEVS=(/dev/sdd)
# Enable zoned block device mode for the block group genertic tests
RUN_ZONED_TESTS=1
# Speed up execution (weaker tests)
QUICK_RUN=1
TIMEOUT=30
Of note is that the block layer generic tests of the block group also include
test cases executed against a logical device (null_blk block device). These
tests are executed twice, once with the null_blk device configured as a
regular block device and a second time with the null_blk device configured as
a zoned block device. To reduce the test cases execution to only the physical
device specified in the configuration file, the DEVICE_ONLY option can be set.
# Tests target device list
TEST_DEVS=(/dev/sdd)
# Enable zoned block device mode for the block group genertic tests
RUN_ZONED_TESTS=1
# Speed up execution (weaker tests)
QUICK_RUN=1
TIMEOUT=30
# Exercise only the devices in TEST_DEVS
DEVICE_ONLY=1
Execution
blktests execution is done using the check script present in the top level
directory. This script optionally takes as argument a list of test groups or
test cases to execute. Bu default, without any argument, all test groups will be
executed.
For zoned block device tests, executing the test cases of the block and zbd test groups is sufficient.
As discussed in the configuration section above, several options can speedup the execution of blktests. Such quick runs are indeed faster but at the cost of weaker testing compared to full runs.
Full Run
The following command executes all test cases relevant to zoned block devices
with the device specified in the config configuration file as target. In this
example, no options are added.
# ./check block zbd
block/001 (stress device hotplugging) [passed]
runtime 120.013s ... 123.440s
block/002 (remove a device while running blktrace) [passed]
runtime 0.741s ... 0.761s
block/003 => sdd (run various discard sizes) [not run]
/dev/sdd is a zoned block device
block/004 => sdd (run lots of flushes) [passed]
runtime 98.876s ... 82.665s
write iops 170 ... 203
block/005 => sdd (switch schedulers while doing IO) [passed]
read iops 1415 ... 791
runtime 6.765s ... 11.242s
block/006 (run null-blk in blocking mode) [passed]
read iops 154220 ... 152356
runtime 19.158s ... 19.229s
block/006 (zoned) (run null-blk in blocking mode) [passed]
read iops 150692 ... 146826
runtime 19.128s ... 19.720s
block/007 => sdd (test classic and hybrid IO polling) [not run]
/dev/sdd is a zoned block device
block/008 (do IO while hotplugging CPUs) [not run]
CPU hotplugging is not supported
block/009 (check page-cache coherency after BLKDISCARD) [passed]
runtime 0.827s ... 0.868s
block/010 (run I/O on null_blk with shared and non-shared tags) [passed]
Individual tags read iops 254661 ... 253371
Shared tags read iops 174876 ... 174933
runtime 695.714s ... 715.579s
block/010 (zoned) (run I/O on null_blk with shared and non-shared tags) [passed]
Individual tags read iops 253356 ... 252487
Shared tags read iops 174871 ... 174780
runtime 667.479s ... 652.577s
block/011 => sdd (disable PCI device while doing I/O) [passed]
runtime 8.293s ... 17.760s
block/012 => sdd (check that a read-only block device fails writes) [not run]
/dev/sdd is a zoned block device
block/013 => sdd (try BLKRRPART on a mounted device) [not run]
/dev/sdd is a zoned block device
block/014 (run null-blk with blk-mq and timeout injection configured) [not run]
null_blk module does not have parameter timeout
block/015 (run null-blk on different schedulers with requeue injection configured) [not run]
null_blk module does not have parameter requeue
block/016 (send a signal to a process waiting on a frozen queue) [passed]
runtime 8.055s ... 8.055s
block/016 (zoned) (send a signal to a process waiting on a frozen queue) [passed]
runtime 8.055s ... 8.055s
block/017 (do I/O and check the inflight counter) [passed]
runtime 1.691s ... 1.675s
block/017 (zoned) (do I/O and check the inflight counter) [passed]
runtime 1.690s ... 1.692s
block/018 (do I/O and check iostats times) [passed]
runtime 5.075s ... 5.077s
block/019 => sdd (break PCI link device while doing I/O) [not run]
/dev/sdd is a zoned block device
block/020 (run null-blk on different schedulers with only one hardware tag) [passed]
runtime 43.139s ... 43.191s
block/020 (zoned) (run null-blk on different schedulers with only one hardware tag) [passed]
runtime 43.120s ... 43.206s
block/021 (read/write nr_requests on null-blk with different schedulers) [passed]
runtime 1.396s ... 1.393s
block/021 (zoned) (read/write nr_requests on null-blk with different schedulers) [passed]
runtime 1.399s ... 1.419s
block/023 (do I/O on all null_blk queue modes) [passed]
runtime 0.276s ... 0.280s
block/023 (zoned) (do I/O on all null_blk queue modes) [passed]
runtime 0.279s ... 0.302s
block/024 (do I/O faster than a jiffy and check iostats times) [passed]
runtime 4.902s ... 4.904s
block/025 (do a huge discard with 4k sector size) [passed]
runtime 8.869s ... 8.921s
block/027 (stress device hotplugging with running fio jobs and different schedulers) [not run]
no support for io cgroup controller; if it is enabled, you may need to boot with cgroup_no_v1=io
block/028 (do I/O on scsi_debug with DIF/DIX enabled) [passed]
runtime 19.924s ... 19.942s
zbd/001 => sdd (sysfs and ioctl) [passed]
runtime ... 0.706s
zbd/002 => sdd (report zone) [passed]
runtime ... 6.534s
zbd/003 => sdd (reset sequential required zones) [passed]
runtime ... 13.324s
zbd/004 => sdd (write split across sequential zones) [passed]
runtime ... 17.019s
zbd/005 => sdd (write command ordering) [passed]
runtime ... 178.335s
write io ... 7196672
write iops ... 933
zbd/006 => sdd (revalidate) [passed]
runtime ... 61.028s
write io ... 1805004
write iops ... 15041
The output of some tests is [not run]. This is not a failure. This only indicates that the target device specified in the configuration file does not support the feature being tested. For example, in the above run, test case block/003 is not executed against the specified host managed disk because the disk does not support the discard command.
Quick Run
blkltests execution can be accelerated using the TIMEOUT, QUICK_RUN and
DEVICE_ONLY configuration options.
# Tests target device list
TEST_DEVS=(/dev/sdd)
# Enable zoned block device mode for the block group genertic tests
RUN_ZONED_TESTS=1
# Speed up execution (weaker tests)
QUICK_RUN=1
TIMEOUT=30
# Exercise only the devices in TEST_DEVS
DEVICE_ONLY=1
Running only the block and zbd test groups with the above configuration gives the following results.
# ./check block zbd
block/003 => sdd (run various discard sizes) [not run]
/dev/sdd is a zoned block device
block/004 => sdd (run lots of flushes) [passed]
runtime 913.097s ... 33.714s
write iops ... 239
block/005 => sdd (switch schedulers while doing IO) [passed]
read iops 2975 ... 3573
runtime 22.510s ... 19.194s
block/007 => sdd (test classic and hybrid IO polling) [not run]
/dev/sdd is a zoned block device
block/008 => sdd (do IO while hotplugging CPUs) [not run]
/dev/sdd is a zoned block device
block/011 => sdd (disable PCI device while doing I/O) [passed]
runtime ... 30.322s
block/012 => sdd (check that a read-only block device fails writes) [not run]
/dev/sdd is a zoned block device
block/013 => sdd (try BLKRRPART on a mounted device) [not run]
/dev/sdd is a zoned block device
block/019 => sdd (break PCI link device while doing I/O) [not run]
/dev/sdd is a zoned block device
zbd/001 => sdd (sysfs and ioctl) [passed]
runtime 1.328s ... 0.521s
zbd/003 => sdd (reset sequential required zones) [passed]
runtime 9.591s ... 11.008s
zbd/004 => sdd (write split across sequential zones) [passed]
runtime 11.772s ... 11.743s
zbd/005 => sdd (write command ordering) [passed]
runtime 59.688s ... 167.521s
write io 7201536 ... 7113472
write iops 933 ... 921
zbd/006 => sdd (revalidate) [passed]
runtime 7.063s ... 39.464s
write io ... 2097152
write iops ... 48971