The recent zvol improvements have changed default suggested alignment
for zvols from 512b (default) to 8k (zvol blocksize). Because of this
the zconfig.sh tests which create paritions are now generating a
warning about non-optimal alignments.
This change updates the need zconfig.sh tests such that a partition
will be properly aligned. In the process, it shifts from using the
sfdisk utility to the parted utility to create partitions. It also
moves the creation of labels, partitions, and filesystems in to
generic functions in common.sh.in.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When running the zconfig.sh, zpios-sanity.sh, and zfault.sh
from the installed packages the 90-zfs.rules can cause failures.
These will occur because the test suite assumes it has full
control over loading/unloading the module stack. If the stack
gets asynchronously loaded by the udev rule the test suite
will treat it as a failure. Resolve the issue by disabling
the offending rule during the tests and enabling it on exit.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When your kernel is built with kernel stack tracing enabled and you
have the debugfs filesystem mounted. Then the zfs.sh script will clear
the worst observed kernel stack depth on module load and check the worst
case usage on module removal. If the stack depth ever exceeds 7000
bytes the full stack will be printed for debugging. This is dangerously
close to overrunning the default 8k stack.
This additional advisory debugging is particularly valuable when running
the regression tests on a kernel built with 16k stacks. In this case,
almost no matter how bad the stack overrun is you will see be able to
get a clean stack trace for debugging. Since the worst case stack usage
can be highly variable it's helpful to always check the worst case usage.
Some udev hooks are not designed to be idempotent, so calling udevadm
trigger outside of the distribution's initialization scripts can have
unexpected (and potentially dangerous) side effects. For example, the
system time may change or devices may appear multiple times. See Ubuntu
launchpad bug 320200 and this mailing list post for more details:
https://lists.ubuntu.com/archives/ubuntu-devel/2009-January/027260.html
To avoid these problems we call udevadm trigger with --action=change
--subsystem-match=block. The first argument tells udev just to refresh
devices, and make sure everything's as it should be. The second
argument limits the scope to block devices, so devices belonging to
other subsystems cannot be affected.
This doesn't fix the problem on older udev implementations that don't
provide udevadm but instead have udevtrigger as a standalone program.
In this case the above options aren't available so there's no way to
call call udevtrigger safely. But we can live with that since this
issue only exists in optional test and helper scripts, and most
zfs-on-linux users are running newer systems anyways.
Loading and unloading the zlib modules as part of the zfs.sh
script has proven a little problematic for a few reasons.
* First, your kernel may not need to load either zlib_inflate
or zlib_deflate. This functionality may be built directly in
to your kernel. It depends entirely on what your distribution
decided was the right thing to do.
* Second, even if you do manage to load the correct modules you
may not be able to unload them. There may other consumers
of the modules with a reference preventing the unload.
To avoid both of these issues the test scripts have been updated to
attempt to unconditionally load all modules listed in KERNEL_MODULES.
If the module is successfully loaded you must have needed it. If
the module can't be loaded that almost certainly means either it is
built in to your kernel or is already being used by another consumer.
In both cases this is not an issue and we can move on to the spl/zfs
modules.
Finally, by removing these kernel modules from the MODULES list
we ensure they are never unloaded during 'zfs.sh -u'. This avoids
the issue of the script failing because there is another consumer
using the module we were not aware of. In other words the script
restricts unloading modules to only the spl/zfs modules.
Closes#78
Eleven new zpool configurations were added to allow testing of various
failure cases. The first 5 zpool configurations leverage the 'faulty'
md device type which allow us to simuluate IO errors at the block layer.
The last 6 zpool configurations leverage the scsi_debug module provided
by modern kernels. This device allows you to create virtual scsi
devices which are backed by a ram disk. With this setup we can verify
the full IO stack by injecting faults at the lowest layer. Both methods
of fault injection are important to verifying the IO stack.
The zfs code itself also provides a mechanism for error injection
via the zinject command line tool. While we should also take advantage
of this appraoch to validate the code it does not address any of the
Linux integration issues which are the most concerning. For the
moment we're trusting that the upstream Solaris guys are running
zinject and would have caught internal zfs logic errors.
Currently, there are 6 r/w test cases layered on top of the 'faulty'
md devices. They include 3 writes tests for soft/transient errors,
hard/permenant errors, and all writes error to the device. There
are 3 matching read tests for soft/transient errors, hard/permenant
errors, and fixable read error with a write. Although for this last
case zfs doesn't do anything special.
The seventh test case verifies zfs detects and corrects checksum
errors. In this case one of the drives is extensively damaged and
by dd'ing over large sections of it. We then ensure zfs logs the
issue and correctly rebuilds the damage.
The next test cases use the scsi_debug configuration to injects error
at the bottom of the scsi stack. This ensures we find any flaws in the
scsi midlayer or our usage of it. Plus it stresses the device specific
retry, timeout, and error handling outside of zfs's control.
The eighth test case is to verify that the system correctly handles an
intermittent device timeout. Here the scsi_debug device drops 1 in N
requests resulting in a retry either at the block level. The ZFS code
does specify the FAILFAST option but it turns out that for this case
the Linux IO stack with still retry the command. The FAILFAST logic
located in scsi_noretry_cmd() does no seem to apply to the simply
timeout case. It appears to be more targeted to specific device or
transport errors from the lower layers.
The ninth test case handles a persistent failure in which the device
is removed from the system by Linux. The test verifies that the failure
is detected, the device is made unavailable, and then can be successfully
re-add when brought back online. Additionally, it ensures that errors
and events are logged to the correct places and the no data corruption
has occured due to the failure.
Occasional failures were observed in zconfig.sh because udev
could be delayed for a few seconds. To handle this the wait_udev
function has been added to wait for timeout seconds for an
expected device before returning an error. By default callers
currently use a 30 seconds timeout which should be much longer
than udev ever needs but not so long to worry the test suite
is hung.
One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory. The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.
For example, this project is designed to work on various different
Linux distributions each of which work slightly differently. This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.
Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution. When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.
wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z
------------------------- run concurrently ----------------------
<ubuntu system> <fedora system> <debian system> <rhel6 system>
mkdir ubuntu mkdir fedora mkdir debian mkdir rhel6
cd ubuntu cd fedora cd debian cd rhel6
../configure ../configure ../configure ../configure
make make make make
make check make check make check make check
This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory. This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.
This branch contains the majority of the changes required to cleanly
intergrate with Linux style special devices (/dev/zfs). Mainly this
means dropping all the Solaris style callbacks and replacing them
with the Linux equivilants.
This patch also adds the onexit infrastructure needed to track
some minimal state between ioctls. Under Linux it would be easy
to do this simply using the file->private_data. But under Solaris
they apparent need to pass the file descriptor as part of the ioctl
data and then perform a lookup in the kernel. Once again to keep
code change to a minimum I've implemented the Solaris solution.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Add autoconf style build infrastructure to the ZFS tree. This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.
Brian Behlendorf
Ned Bass