Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:
7638 Refactor spa_load_impl into several functions
8961 SPA load/import should tell us why it failed
7277 zdb should be able to print zfs_dbgmsg's
To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.
The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.
The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.
When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.
This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.
With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
of data, this feature is for now restricted to a read-only import.
Porting notes (ZTS):
* Fix 'make dist' target in zpool_import
* The maximum path length allowed by tar is 99 characters. Several
of the new test cases exceeded this limit resulting in them not
being included in the tarball. Shorten the names slightly.
* Set/get tunables using accessor functions.
* Get last synced txg via the "zfs_txg_history" mechanism.
* Clear zinject handlers in cleanup for import_cache_device_replaced
and import_rewind_device_replaced in order that the zpool can be
exported if there is an error.
* Increase FILESIZE to 8G in zfs-test.sh to allow for a larger
ext4 file system to be created on ZFS_DISK2. Also, there's
no need to partition ZFS_DISK2 at all. The partitioning had
already been disabled for multipath devices. Among other things,
the partitioning steals some space from the ext4 file system,
makes it difficult to accurately calculate the paramters to
parted and can make some of the tests fail.
* Increase FS_SIZE and FILE_SIZE in the zpool_import test
configuration now that FILESIZE is larger.
* Write more data in order that device evacuation take lonnger in
a couple tests.
* Use mkdir -p to avoid errors when the directory already exists.
* Remove use of sudo in import_rewind_config_changed.
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/9075
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/619c0123Closes#7459
Authored by: Chris Williamson <chris.williamson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Don Brady <don.brady@delphix.com>
Ported-by: John Kennedy <john.kennedy@delphix.com>
OpenZFS-issue: https://www.illumos.org/issues/7431
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/dfc11533
Porting Notes:
* The CLI long option arguments for '-t' and '-m' don't parse on linux
* Switched from kmem_alloc to vmem_alloc in zcp_lua_alloc
* Lua implementation is built as its own module (zlua.ko)
* Lua headers consumed directly by zfs code moved to 'include/sys/lua/'
* There is no native setjmp/longjump available in stock Linux kernel.
Brought over implementations from illumos and FreeBSD
* The get_temporary_prop() was adapted due to VFS platform differences
* Use of inline functions in lua parser to reduce stack usage per C call
* Skip some ZFS Test Suite ZCP tests on sparc64 to avoid stack overflow
The intent of this patch is extend the existing deadman code
such that it's flexible enough to be used by both ztest and
on production systems. The proposed changes include:
* Added a new `zfs_deadman_failmode` module option which is
used to dynamically control the behavior of the deadman. It's
loosely modeled after, but independant from, the pool failmode
property. It can be set to wait, continue, or panic.
* wait - Wait for the "hung" I/O (default)
* continue - Attempt to recover from a "hung" I/O
* panic - Panic the system
* Added a new `zfs_deadman_ziotime_ms` module option which is
analogous to `zfs_deadman_synctime_ms` except instead of
applying to a pool TXG sync it applies to zio_wait(). A
default value of 300s is used to define a "hung" zio.
* The ztest deadman thread has been re-enabled by default,
aligned with the upstream OpenZFS code, and then extended
to terminate the process when it takes significantly longer
to complete than expected.
* The -G option was added to ztest to print the internal debug
log when a fatal error is encountered. This same option was
previously added to zdb in commit fa603f82. Update zloop.sh
to unconditionally pass -G to obtain additional debugging.
* The FM_EREPORT_ZFS_DELAY event which was previously posted
when the deadman detect a "hung" pool has been replaced by
a new dedicated FM_EREPORT_ZFS_DEADMAN event.
* The proposed recovery logic attempts to restart a "hung"
zio by calling zio_interrupt() on any outstanding leaf zios.
We may want to further restrict this to zios in either the
ZIO_STAGE_VDEV_IO_START or ZIO_STAGE_VDEV_IO_DONE stages.
Calling zio_interrupt() is expected to only be useful for
cases when an IO has been submitted to the physical device
but for some reasonable the completion callback hasn't been
called by the lower layers. This shouldn't be possible but
has been observed and may be caused by kernel/driver bugs.
* The 'zfs_deadman_synctime_ms' default value was reduced from
1000s to 600s.
* Depending on how ztest fails there may be no cache file to
move. This should not be considered fatal, collect the logs
which are available and carry on.
* Add deadman test cases for spa_deadman() and zio_wait().
* Increase default zfs_deadman_checktime_ms to 60s.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6999
For ztest, which is solely for testing, using a pseudo random
is entirely reasonable. Using /dev/urandom ensures the system
entropy pool doesn't get depleted thus stalling the testing.
This is a particular problem when testing in VMs.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7017Closes#7036
Porting Notes:
- The OpenZFS patch added nicenum_scale() and nicenum() to a
library not used by ZFS. Rather than pull in a new dependency
the version of nicenum in lib/libzpool/util.c was simply
replaced with the new one.
Reviewed by: Sebastian Wiedenroth <wiedi@frubar.net>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Yuri Pankov <yuripv@gmx.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Authored by: Jason King <jason.brian.king@gmail.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/640
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/0a055120Closes#6796
* Simplify threads, mutexs, cvs and rwlocks
* Update the zk_thread_create() function to use the same trick
as Illumos. Specifically, cast the new pthread_t to a void
pointer and return that as the kthread_t *. This avoids the
issues associated with managing a wrapper structure and is
safe as long as the callers never attempt to dereference it.
* Update all function prototypes passed to pthread_create() to
match the expected prototype. We were getting away this with
before since the function were explicitly cast.
* Replaced direct zk_thread_create() calls with thread_create()
for code consistency. All consumers of libzpool now use the
proper wrappers.
* The mutex_held() calls were converted to MUTEX_HELD().
* Removed all mutex_owner() calls and retired the interface.
Instead use MUTEX_HELD() which provides the same information
and allows the implementation details to be hidden. In this
case the use of the pthread_equals() function.
* The kthread_t, kmutex_t, krwlock_t, and krwlock_t types had
any non essential fields removed. In the case of kthread_t
and kcondvar_t they could be directly typedef'd to pthread_t
and pthread_cond_t respectively.
* Removed all extra ASSERTS from the thread, mutex, rwlock, and
cv wrapper functions. In practice, pthreads already provides
the vast majority of checks as long as we check the return
code. Removing this code from our wrappers help readability.
* Added TS_JOINABLE state flag to pass to request a joinable rather
than detached thread. This isn't a standard thread_create() state
but it's the least invasive way to pass this information and is
only used by ztest.
TEST_ZTEST_TIMEOUT=3600
Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4547Closes#5503Closes#5523Closes#6377Closes#6495
OpenZFS provides a library called tpool which implements thread
pools for user space applications. Porting this library means
the zpool utility no longer needs to borrow the kernel mutex and
taskq interfaces from libzpool. This code was updated to use
the tpool library which behaves in a very similar fashion.
Porting libtpool was relatively straight forward and minimal
modifications were needed. The core changes were:
* Fully convert the library to use pthreads.
* Updated signal handling.
* lmalloc/lfree converted to calloc/free
* Implemented portable pthread_attr_clone() function.
Finally, update the build system such that libzpool.so is no
longer linked in to zfs(8), zpool(8), etc. All that is required
is libzfs to which the zcommon soures were added (which is the way
it always should have been). Removing the libzpool dependency
resulted in several build issues which needed to be resolved.
* Moved zfeature support to module/zcommon/zfeature_common.c
* Moved ratelimiting to to module/zfs/zfs_ratelimit.c
* Moved get_system_hostid() to lib/libspl/gethostid.c
* Removed use of cmn_err() in zcommon source
* Removed dprintf_setup() call from zpool_main.c and zfs_main.c
* Removed highbit() and lowbit()
* Removed unnecessary library dependencies from Makefiles
* Removed fletcher-4 kstat in user space
* Added sha2 support explicitly to libzfs
* Added highbit64() and lowbit64() to zpool_util.c
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6442
Redefine the SET_ERROR macro in terms of __dprintf() so the error
return codes get logged as both tracepoint events (if tracepoints are
enabled) and as ZFS debug log entries. This also allows us to use
the same definition of SET_ERROR() in kernel and user space.
Define a new debug flag ZFS_DEBUG_SET_ERROR=512 that may be bitwise
or'd into zfs_flags. Setting this flag enables both dprintf() and
SET_ERROR() messages in the debug log. That is, setting
ZFS_DEBUG_SET_ERROR and ZFS_DEBUG_DPRINTF|ZFS_DEBUG_SET_ERROR are
equivalent (this was done for sake of simplicity). Leaving
ZFS_DEBUG_SET_ERROR unset suppresses the SET_ERROR() messages which
helps avoid cluttering up the logs.
To enable SET_ERROR() logging, run:
echo 1 > /sys/module/zfs/parameters/zfs_dbgmsg_enable
echo 512 > /sys/module/zfs/parameters/zfs_flags
Remove the zfs_set_error_class tracepoints event class since
SET_ERROR() now uses __dprintf(). This sacrifices a bit of
granularity when selecting individual tracepoint events to enable but
it makes the code simpler.
Include file, function, and line number information in debug log
entries. The information is now added to the message buffer in
__dprintf() and as a result the zfs_dprintf_class tracepoints event
class was changed from a 4 parameter interface to a single parameter.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#6400
zfsonlinux/spl@8f87971 added __spl_pf_fstrans_check for the xfs related
check, so we use them accordingly.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes#6113
Porting notes:
- Several direct callers of zk_thread_create() are passing TS_RUN for the
length. The `len` and `state` were inverted,this commit fixes them.
Authored by: Eli Rosenthal <eli.rosenthal@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov mail@gmelikov.ru
OpenZFS-issue: https://www.illumos.org/issues/6871
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/8fc9228Closes#5621
This change introduces a new weighting algorithm to improve
metaslab selection. The new weighting algorithm relies on the
SPACEMAP_HISTOGRAM feature. As a result, the metaslab weight
now encodes the type of weighting algorithm used (size-based
vs segment-based).
Porting Notes: The metaslab allocation tracing code is conditionally
removed on linux (dependent on mdb debugger).
Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Chris Siden <christopher.siden@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Pavel Zakharov pavel.zakharov@delphix.com
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Don Brady <don.brady@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Don Brady <don.brady@intel.com>
OpenZFS-issue: https://www.illumos.org/issues/7303
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d5190931bdCloses#5404
Use it for spa_deadman, zpl_posix_acl_free, snapentry_expire.
This free system_taskq from the above long delay tasks, and allow us to do
taskq_wait_outstanding on system_taskq without being blocked forever, making
system_taskq more generic and useful.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Add the TASKQID_INVALID macros and update callers to use the macro
instead of testing against 0. There is no functional change
even though the functions in zfs_ctldir.c incorrectly used -1
instead of 0.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5347
perf: 2.75x faster ddt_entry_compare()
First 256bits of ddt_key_t is a block checksum, which are expected
to be close to random data. Hence, on average, comparison only needs to
look at first few bytes of the keys. To reduce number of conditional
jump instructions, the result is computed as: sign(memcmp(k1, k2)).
Sign of an integer 'a' can be obtained as: `(0 < a) - (a < 0)` := {-1, 0, 1} ,
which is computed efficiently. Synthetic performance evaluation of
original and new algorithm over 1G random keys on 2.6GHz Intel(R) Xeon(R)
CPU E5-2660 v3:
old 6.85789 s
new 2.49089 s
perf: 2.8x faster vdev_queue_offset_compare() and vdev_queue_timestamp_compare()
Compute the result directly instead of using conditionals
perf: zfs_range_compare()
Speedup between 1.1x - 2.5x, depending on compiler version and
optimization level.
perf: spa_error_entry_compare()
`bcmp()` is not suitable for comparator use. Use `memcmp()` instead.
perf: 2.8x faster metaslab_compare() and metaslab_rangesize_compare()
perf: 2.8x faster zil_bp_compare()
perf: 2.8x faster mze_compare()
perf: faster dbuf_compare()
perf: faster compares in spa_misc
perf: 2.8x faster layout_hash_compare()
perf: 2.8x faster space_reftree_compare()
perf: libzfs: faster avl tree comparators
perf: guid_compare()
perf: dsl_deadlist_compare()
perf: perm_set_compare()
perf: 2x faster range_tree_seg_compare()
perf: faster unique_compare()
perf: faster vdev_cache _compare()
perf: faster vdev_uberblock_compare()
perf: faster fuid _compare()
perf: faster zfs_znode_hold_compare()
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Richard Elling <richard.elling@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#5033
Authored by: Hans Rosenfeld <hans.rosenfeld@nexenta.com>
Reviewed by: Dan Fields <dan.fields@nexenta.com>
Reviewed by: Josef Sipek <josef.sipek@nexenta.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Signed-off-by: Don Brady <don.brady@intel.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/5997
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/1437283
Porting Notes:
In addition to the OpenZFS changes this patch realigns the events
with those found in OpenZFS.
Events which would be logged as sysevents on illumos have been
been mapped to the 'sysevent' class for Linux. In addition, several
subclass names have been changed to match what is used in OpenZFS.
In all cases this means a '.' was changed to an '_' in the subclass.
The scripts provided by ZoL have been updated, however users which
provide scripts for any of the following events will need to rename
them based on the new subclass names.
ereport.fs.zfs.config.sync sysevent.fs.zfs.config_sync
ereport.fs.zfs.zpool.destroy sysevent.fs.zfs.pool_destroy
ereport.fs.zfs.zpool.reguid sysevent.fs.zfs.pool_reguid
ereport.fs.zfs.vdev.remove sysevent.fs.zfs.vdev_remove
ereport.fs.zfs.vdev.clear sysevent.fs.zfs.vdev_clear
ereport.fs.zfs.vdev.check sysevent.fs.zfs.vdev_check
ereport.fs.zfs.vdev.spare sysevent.fs.zfs.vdev_spare
ereport.fs.zfs.vdev.autoexpand sysevent.fs.zfs.vdev_autoexpand
ereport.fs.zfs.resilver.start sysevent.fs.zfs.resilver_start
ereport.fs.zfs.resilver.finish sysevent.fs.zfs.resilver_finish
ereport.fs.zfs.scrub.start sysevent.fs.zfs.scrub_start
ereport.fs.zfs.scrub.finish sysevent.fs.zfs.scrub_finish
ereport.fs.zfs.bootfs.vdev.attach sysevent.fs.zfs.bootfs_vdev_attach
A port of the Illumos Crypto Framework to a Linux kernel module (found
in module/icp). This is needed to do the actual encryption work. We cannot
use the Linux kernel's built in crypto api because it is only exported to
GPL-licensed modules. Having the ICP also means the crypto code can run on
any of the other kernels under OpenZFS. I ended up porting over most of the
internals of the framework, which means that porting over other API calls (if
we need them) should be fairly easy. Specifically, I have ported over the API
functions related to encryption, digests, macs, and crypto templates. The ICP
is able to use assembly-accelerated encryption on amd64 machines and AES-NI
instructions on Intel chips that support it. There are place-holder
directories for similar assembly optimizations for other architectures
(although they have not been written).
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4329
ZFS allows for specific permissions to be delegated to normal users
with the `zfs allow` and `zfs unallow` commands. In addition, non-
privileged users should be able to run all of the following commands:
* zpool [list | iostat | status | get]
* zfs [list | get]
Historically this functionality was not available on Linux. In order
to add it the secpolicy_* functions needed to be implemented and mapped
to the equivalent Linux capability. Only then could the permissions on
the `/dev/zfs` be relaxed and the internal ZFS permission checks used.
Even with this change some limitations remain. Under Linux only the
root user is allowed to modify the namespace (unless it's a private
namespace). This means the mount, mountpoint, canmount, unmount,
and remount delegations cannot be supported with the existing code. It
may be possible to add this functionality in the future.
This functionality was validated with the cli_user and delegation test
cases from the ZFS Test Suite. These tests exhaustively verify each
of the supported permissions which can be delegated and ensures only
an authorized user can perform it.
Two minor bug fixes were required for test-running.py. First, the
Timer() object cannot be safely created in a `try:` block when there
is an unconditional `finally` block which references it. Second,
when running as a normal user also check for scripts using the
both the .ksh and .sh suffixes.
Finally, existing users who are simulating delegations by setting
group permissions on the /dev/zfs device should revert that
customization when updating to a version with this change.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#362Closes#434Closes#4100Closes#4394Closes#4410Closes#4487
Userland version of cv_timedwait_hires() always assumes absolute time.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported by: Denys Rtveliashvili <denys@rtveliashvili.name>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/6739
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/41c6413
Porting Notes:
The ported change has revealed a number of problems in the Linux-specific code,
as it was expecting incorrect return codes from pthread_* functions.
Reviewed and improved the usage of pthread_* function in lib/libzpool/kernel.c.
The was originally using interruptible cv_timedwait_sig, but was changed
to uninterruptible cv_timedwait_hires in ae6d0c6. Use _sig_hires instead
to allow interruptible sleep.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4633Closes#4634
When compiling with musl libc the return type will be incorrect.
Signed-off-by: Carlo Landmeter <clandmeter@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4454
6815179 zpool import with a large number of LUNs is too slow
6844191 zpool import, scanning of disks should be multi-threaded
References:
https://github.com/illumos/illumos-gate/commit/4f67d75
Porting notes:
- This change was originally never ported to Linux due to it
dependence on the thread pool interface. This patch solves
that issue by switching the code to use the existing taskq
implementation which provides the same basic functionality.
However, in order for this to work properly thread_init()
and thread_fini() must be called around to taskq consumer
to perform the needed thread initialization.
- The check_one_slice, nozpool_all_slices, and check_slices
functions have been disabled for Linux. They are difficult,
but possible, to implement for Linux due to how partitions
are get names. Since this is only an optimization this code
can be added at a latter date.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Under RHEL6/CentOS6 the default stack size must be increased to 32K
to prevent overflowing the stack when running ztest. This isn't an
issue for other distributions due to either the version of pthreads
or perhaps the compiler. Doubling the stack size resolves the
issue safely for all distribution and leaves us some headroom.
$ sudo -E ztest -V -T 300 -f /var/tmp/
5 vdevs, 7 datasets, 23 threads, 300 seconds...
loading space map for vdev 0 of 1, metaslab 0 of 30 ...
...
loading space map for vdev 0 of 1, metaslab 14 of 30 ...
child died with signal 11
Exited ztest with error 3
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4215
4891 want zdb option to dump all metadata
Reviewed by: Sonu Pillai <sonu.pillai@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
We'd like a way for zdb to dump metadata in a machine-readable
format, so that we can bring that back from a customer site for
in-house diagnosis. Think of it as a crash dump for zpools,
which can be used for post-mortem analysis of a malfunctioning
pool
References:
https://www.illumos.org/issues/4891https://github.com/illumos/illumos-gate/commit/df15e41
Porting notes:
- [cmd/zdb/zdb.c]
- a5778ea zdb: Introduce -V for verbatim import
- In main() getopt 'opt' variable removed and the code was
brought back in line with illumos.
- [lib/libzpool/kernel.c]
- 1e33ac1 Fix Solaris thread dependency by using pthreads
- f0e324f Update utsname support
- 4d58b69 Fix vn_open/vn_rdwr error handling
- In vn_open() allocate 'dumppath' on heap instead of stack
- Properly handle 'dump_fd == -1' error path
- Free 'realpath' after added vn_dumpdir_code block
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Both lock types were introduced in SPL to allow some locks to be
taken/released with linux lockdep turned off. See SPL commit for
details.
Add the new lock types to zfs_context.h to allow user space compilation.
Depends on SPL commit 692ae8d
SPL pull request refs/pull/480/head
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3895
Under Linux filesystem threads responsible for handling I/O are
normally created with the maximum priority. Non-I/O filesystem
processes run with the default priority. ZFS should adopt the
same priority scheme under Linux to maintain good performance
and so that it will complete fairly when other Linux filesystems
are active. The priorities have been updated to the following:
$ ps -eLo rtprio,cls,pid,pri,nice,cmd | egrep 'z_|spl_|zvol|arc|dbu|meta'
- TS 10743 19 -20 [spl_kmem_cache]
- TS 10744 19 -20 [spl_system_task]
- TS 10745 19 -20 [spl_dynamic_tas]
- TS 10764 19 0 [dbu_evict]
- TS 10765 19 0 [arc_prune]
- TS 10766 19 0 [arc_reclaim]
- TS 10767 19 0 [arc_user_evicts]
- TS 10768 19 0 [l2arc_feed]
- TS 10769 39 0 [z_unmount]
- TS 10770 39 -20 [zvol]
- TS 11011 39 -20 [z_null_iss]
- TS 11012 39 -20 [z_null_int]
- TS 11013 39 -20 [z_rd_iss]
- TS 11014 39 -20 [z_rd_int_0]
- TS 11022 38 -19 [z_wr_iss]
- TS 11023 39 -20 [z_wr_iss_h]
- TS 11024 39 -20 [z_wr_int_0]
- TS 11032 39 -20 [z_wr_int_h]
- TS 11033 39 -20 [z_fr_iss_0]
- TS 11041 39 -20 [z_fr_int]
- TS 11042 39 -20 [z_cl_iss]
- TS 11043 39 -20 [z_cl_int]
- TS 11044 39 -20 [z_ioctl_iss]
- TS 11045 39 -20 [z_ioctl_int]
- TS 11046 39 -20 [metaslab_group_]
- TS 11050 19 0 [z_iput]
- TS 11121 38 -19 [z_wr_iss]
Note that under Linux the meaning of a processes priority is inverted
with respect to illumos. High values on Linux indicate a _low_ priority
while high value on illumos indicate a _high_ priority.
In order to preserve the logical meaning of the minclsyspri and
maxclsyspri macros when they are used by the illumos wrapper functions
their values have been inverted. This way when changes are merged
from upstream illumos we won't need to remember to invert the macro.
It could also lead to confusion.
This patch depends on https://github.com/zfsonlinux/spl/pull/466.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#3607
5376 arc_kmem_reap_now() should not result in clearing arc_no_grow
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5376https://github.com/illumos/illumos-gate/commit/2ec99e3
Porting Notes:
The good news is that many of the recent changes made upstream to the
ARC tackled issues previously observed by ZoL with similar solutions.
The bad news is those solution weren't identical to the ones we applied.
This patch is designed to split the difference and apply as much of the
upstream work as possible.
* The arc_available_memory() function was removed previous in ZoL but
due to the upstream changes it makes sense to add it back. This function
has been customized for Linux so that it can be used to determine a low
memory. This provides the same basic functionality as the illumos version
allowing us to minimize changes through the rest of the code base. The
exact mechanism used to detect a low memory state remains unchanged so
this change isn't a significant as it might first appear.
* This patch includes the long standing fix for arc_shrink() which was
originally proposed in #2167. Since there were related changes to this
function it made sense to include that work.
* The arc_init() function has been re-factored. As before it sets sane
default values for the ARC but then calls arc_tuning_update() to apply
user specific tuning made via module options. The arc_tuning_update()
function is then called periodically by the arc_reclaim_thread() to
apply changes to the tunings made during normal operation.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3616Closes#2167
5163 arc should reap range_seg_cache
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5163https://github.com/illumos/illumos-gate/commit/83803b5
Porting Notes:
Added umem_cache_reap_now() wrapped to suppress unused variable
warning for user space build in arc_kmem_reap_now().
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
This is the counterpart to zfsonlinux/spl@2345368 which replaces the
cv_wait_interruptible() function with cv_wait_sig(). There is no
functional change to patch merely brings the function names in to
sync to maximize portability.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3450
Issue #3402
SPL commit behlendorf/spl@9cef1b5 adds the taskq_wait_outstanding()
interface. See the commit log for the full justification for this
addition. This patch adds the required user space counterpart.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Porting notes and other significant code changes:
The illumos 5368 patch (ARC should cache more metadata), which
was never picked up by ZoL, is mostly reverted by this patch.
Since ZoL relies on the kernel asynchronously calling the shrinker to
actually reap memory, the shrinker wakes up arc_reclaim_waiters_cv every
time it runs.
The arc_adapt_thread() function no longer calls arc_do_user_evicts()
since the newly-added arc_user_evicts_thread() calls it periodically.
Notable conflicting ZoL commits which conflicted with this patch or
whose effects are either duplicated or un-done by this patch:
302f753 - Integrate ARC more tightly with Linux
39e055c - Adjust arc_p based on "bytes" in arc_shrink
f521ce1 - Allow "arc_p" to drop to zero or grow to "arc_c"
77765b5 - Remove "arc_meta_used" from arc_adjust calculation
94520ca - Prune metadata from ghost lists in arc_adjust_meta
Trace support for multilist_insert() and multilist_remove() has been
added and produces the following output:
fio-12498 [077] .... 112936.448324: zfs_multilist__insert: ml { offset 240 numsublists 80 sublistidx 63 }
fio-12498 [077] .... 112936.448347: zfs_multilist__remove: ml { offset 240 numsublists 80 sublistidx 29 }
The following arcstats have been removed:
recycle_miss - Used by arcstat.py and arc_summary.py, both of which
have been updated appropriately.
l2_writes_hdr_miss
The following arcstats have been added:
evict_not_enough - Number of times arc_evict_state() was unable to
evict enough buffers to reach its target amount.
evict_l2_skip - Number of times arc_evict_hdr() skipped eviction
because it was being written to the l2arc.
l2_writes_lock_retry - Replaces l2_writes_hdr_miss. Number of times
l2arc_write_done() failed to acquire hash_lock (and re-tries).
arc_meta_min - Shows the value of the zfs_arc_meta_min module
parameter (see below).
The "index" column of the "dbuf" kstat has been removed since it doesn't
have a direct analog in the new multilist scheme. Additional multilist-
related stats could be added in the future but would likely require
extensions to the mulilist API.
The following module parameters have been added:
zfs_arc_evict_batch_limit - Number of ARC headers to free per sub-list
before moving on to the next sub-list.
zfs_arc_meta_min - Enforce a floor on the amount of metadata in
the ARC.
zfs_arc_num_sublists_per_state - Number of multilist sub-lists per
ARC state.
zfs_arc_overflow_shift - Controls amount by which the ARC must exceed
the target size to be considered "overflowing".
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov
Prevent deadlocks by disabling direct reclaim during all ZPL and ioctl
calls as well as the l2arc and adapt ARC threads.
This obviates the need for MUTEX_FSTRANS so its previous uses and
definition have been eliminated.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3225
There are regions in the ZFS code where it is desirable to be able
to be set PF_FSTRANS while a specific mutex is held. The ZFS code
could be updated to set/clear this flag in all the correct places,
but this is undesirable for a few reasons.
1) It would require changes to a significant amount of the ZFS
code. This would complicate applying patches from upstream.
2) It would be easy to accidentally miss a critical region in
the initial patch or to have an future change introduce a
new one.
Both of these concerns can be addressed by using a new mutex type
which is responsible for managing PF_FSTRANS, support for which was
added to the SPL in commit zfsonlinux/spl@9099312 - Merge branch
'kmem-rework'.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3050Closes#3055Closes#3062Closes#3132Closes#3142Closes#2983
As part of the spl kmem/vmem refactoring the kmem_cache_* functions
were split in to their own kmem_cache.h header. This was done in
part so that kmem_* consumers would not be forced to include the
kmem_cache_* functions which mask several Linux SLAB/SLAB functions.
Because of this we now much explicitly include kmem_cache.h in the
zfs_context.h. However, consumers such as Lustre which need access
to the KM_FLAGS but not the kmem_cache_* functions can now safely
just include kmem.h.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
By marking DMU transaction processing contexts with PF_FSTRANS
we can revert the KM_PUSHPAGE -> KM_SLEEP changes. This brings
us back in line with upstream. In some cases this means simply
swapping the flags back. For others fnvlist_alloc() was replaced
by nvlist_alloc(..., KM_PUSHPAGE) and must be reverted back to
fnvlist_alloc() which assumes KM_SLEEP.
The one place KM_PUSHPAGE is kept is when allocating ARC buffers
which allows us to dip in to reserved memory. This is again the
same as upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Callers of kmem_alloc() which passed the KM_NODEBUG flag to suppress
the large allocation warning have been replaced by vmem_alloc() as
appropriate. The updated vmem_alloc() call will not print a warning
regardless of the size of the allocation.
A careful reader will notice that not all callers have been changed
to vmem_alloc(). Some have only had the KM_NODEBUG flag removed.
This was possible because the default warning threshold has been
increased to 32k. This is desirable because it minimizes the need
for Linux specific code changes.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
In order to avoid deadlocking in the IO pipeline it is critical that
pageout be avoided during direct memory reclaim. This ensures that
the pipeline threads can always make forward progress and never end
up blocking on a DMU transaction. For this very reason Linux now
provides the PF_FSTRANS flag which may be set in the process context.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This patch leverages Linux tracepoints from within the ZFS on Linux
code base. It also refactors the debug code to bring it back in sync
with Illumos.
The information exported via tracepoints can be used for a variety of
reasons (e.g. debugging, tuning, general exploration/understanding,
etc). It is advantageous to use Linux tracepoints as the mechanism to
export this kind of information (as opposed to something else) for a
number of reasons:
* A number of external tools can make use of our tracepoints
"automatically" (e.g. perf, systemtap)
* Tracepoints are designed to be extremely cheap when disabled
* It's one of the "accepted" ways to export this kind of
information; many other kernel subsystems use tracepoints too.
Unfortunately, though, there are a few caveats as well:
* Linux tracepoints appear to only be available to GPL licensed
modules due to the way certain kernel functions are exported.
Thus, to actually make use of the tracepoints introduced by this
patch, one might have to patch and re-compile the kernel;
exporting the necessary functions to non-GPL modules.
* Prior to upstream kernel version v3.14-rc6-30-g66cc69e, Linux
tracepoints are not available for unsigned kernel modules
(tracepoints will get disabled due to the module's 'F' taint).
Thus, one either has to sign the zfs kernel module prior to
loading it, or use a kernel versioned v3.14-rc6-30-g66cc69e or
newer.
Assuming the above two requirements are satisfied, lets look at an
example of how this patch can be used and what information it exposes
(all commands run as 'root'):
# list all zfs tracepoints available
$ ls /sys/kernel/debug/tracing/events/zfs
enable filter zfs_arc__delete
zfs_arc__evict zfs_arc__hit zfs_arc__miss
zfs_l2arc__evict zfs_l2arc__hit zfs_l2arc__iodone
zfs_l2arc__miss zfs_l2arc__read zfs_l2arc__write
zfs_new_state__mfu zfs_new_state__mru
# enable all zfs tracepoints, clear the tracepoint ring buffer
$ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
$ echo 0 > /sys/kernel/debug/tracing/trace
# import zpool called 'tank', inspect tracepoint data (each line was
# truncated, they're too long for a commit message otherwise)
$ zpool import tank
$ cat /sys/kernel/debug/tracing/trace | head -n35
# tracer: nop
#
# entries-in-buffer/entries-written: 1219/1219 #P:8
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss: hdr...
z_rd_int/0-30156 [003] .... 91344.200611: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.201173: zfs_arc__miss: hdr...
z_rd_int/1-30157 [003] .... 91344.201756: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.201795: zfs_arc__miss: hdr...
z_rd_int/2-30158 [003] .... 91344.202099: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202126: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202130: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202134: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202146: zfs_arc__miss: hdr...
z_rd_int/3-30159 [003] .... 91344.202457: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202484: zfs_arc__miss: hdr...
z_rd_int/4-30160 [003] .... 91344.202866: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202891: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.203034: zfs_arc__miss: hdr...
z_rd_iss/1-30149 [001] .... 91344.203749: zfs_new_state__mru...
lt-zpool-30132 [001] .... 91344.203789: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.203878: zfs_arc__miss: hdr...
z_rd_iss/3-30151 [001] .... 91344.204315: zfs_new_state__mru...
lt-zpool-30132 [001] .... 91344.204332: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204337: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204352: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204356: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204360: zfs_arc__hit: hdr ...
To highlight the kind of detailed information that is being exported
using this infrastructure, I've taken the first tracepoint line from the
output above and reformatted it such that it fits in 80 columns:
lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss:
hdr {
dva 0x1:0x40082
birth 15491
cksum0 0x163edbff3a
flags 0x640
datacnt 1
type 1
size 2048
spa 3133524293419867460
state_type 0
access 0
mru_hits 0
mru_ghost_hits 0
mfu_hits 0
mfu_ghost_hits 0
l2_hits 0
refcount 1
} bp {
dva0 0x1:0x40082
dva1 0x1:0x3000e5
dva2 0x1:0x5a006e
cksum 0x163edbff3a:0x75af30b3dd6:0x1499263ff5f2b:0x288bd118815e00
lsize 2048
} zb {
objset 0
object 0
level -1
blkid 0
}
For the specific tracepoint shown here, 'zfs_arc__miss', data is
exported detailing the arc_buf_hdr_t (hdr), blkptr_t (bp), and
zbookmark_t (zb) that caused the ARC miss (down to the exact DVA!).
This kind of precise and detailed information can be extremely valuable
when trying to answer certain kinds of questions.
For anybody unfamiliar but looking to build on this, I found the XFS
source code along with the following three web links to be extremely
helpful:
* http://lwn.net/Articles/379903/
* http://lwn.net/Articles/381064/
* http://lwn.net/Articles/383362/
I should also node the more "boring" aspects of this patch:
* The ZFS_LINUX_COMPILE_IFELSE autoconf macro was modified to
support a sixth paramter. This parameter is used to populate the
contents of the new conftest.h file. If no sixth parameter is
provided, conftest.h will be empty.
* The ZFS_LINUX_TRY_COMPILE_HEADER autoconf macro was introduced.
This macro is nearly identical to the ZFS_LINUX_TRY_COMPILE macro,
except it has support for a fifth option that is then passed as
the sixth parameter to ZFS_LINUX_COMPILE_IFELSE.
These autoconf changes were needed to test the availability of the Linux
tracepoint macros. Due to the odd nature of the Linux tracepoint macro
API, a separate ".h" must be created (the path and filename is used
internally by the kernel's define_trace.h file).
* The HAVE_DECLARE_EVENT_CLASS autoconf macro was introduced. This
is to determine if we can safely enable the Linux tracepoint
functionality. We need to selectively disable the tracepoint code
due to the kernel exporting certain functions as GPL only. Without
this check, the build process will fail at link time.
In addition, the SET_ERROR macro was modified into a tracepoint as well.
To do this, the 'sdt.h' file was moved into the 'include/sys' directory
and now contains a userspace portion and a kernel space portion. The
dprintf and zfs_dbgmsg* interfaces are now implemented as tracepoint as
well.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Modify the code to use the utsname() kernel function rather than
a global variable. This results is cleaner more portable code
because utsname() is already provided by the kernel and can be
easily emulated in user space via uname(2). This means that it
will behave consistently in both contexts.
This is also has the benefit that it allows the removal of a few
_KERNEL pre-processor conditions. And it also is a pre-requisite
for a proper FUSE port because we need to provide a valid utsname.
Finally, it allows us to remove this functionality from the SPL
and all the related compatibility code.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2757
To aid in detecting and debugging stack overflow issues make the
user space stack limit configurable via a new ZFS_STACK_SIZE
environment variable. The value assigned to ZFS_STACK_SIZE will
be used as the default stack size in bytes.
Because this is mainly useful as a debugging aid in conjunction
with ztest the stack limit is disabled by default. See the ztest(1)
man page for additional details on using the ZFS_STACK_SIZE
environment variable.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#2743
Issue #2293
Most of the code base already uses va_list, which is specified by
iso-c. gcc/glibc provides 'typedef __gnuc_va_list va_list'. and
when not using gcc/glibc we can't expect to find __gnuc_va_list.
Signed-off-by: Alec Salazar <alec.j.salazar@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2588
4374 dn_free_ranges should use range_tree_t
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4374https://github.com/illumos/illumos-gate/commit/bf16b11
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2531
This implements a subset of the LWP rwlock interface by wrapping the
equivalent POSIX thread interface. It is a superset of the features
needed by ztest.
The missing bits are {,_}rw_read_held() and {,_}rw_write_held().
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1970
Also, make sure we use clock_t for ddi_get_lbolt to prevent type conversion
from screwing things.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2142
The vast majority of these changes are in Linux specific code.
They are the result of not having an automated style checker to
validate the code when it was originally written. Others were
caused when the common code was slightly adjusted for Linux.
This patch contains no functional changes. It only refreshes
the code to conform to style guide.
Everyone submitting patches for inclusion upstream should now
run 'make checkstyle' and resolve any warning prior to opening
a pull request. The automated builders have been updated to
fail a build if when 'make checkstyle' detects an issue.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1821
4045 zfs write throttle & i/o scheduler performance work
1. The ZFS i/o scheduler (vdev_queue.c) now divides i/os into 5 classes: sync
read, sync write, async read, async write, and scrub/resilver. The scheduler
issues a number of concurrent i/os from each class to the device. Once a class
has been selected, an i/o is selected from this class using either an elevator
algorithem (async, scrub classes) or FIFO (sync classes). The number of
concurrent async write i/os is tuned dynamically based on i/o load, to achieve
good sync i/o latency when there is not a high load of writes, and good write
throughput when there is. See the block comment in vdev_queue.c (reproduced
below) for more details.
2. The write throttle (dsl_pool_tempreserve_space() and
txg_constrain_throughput()) is rewritten to produce much more consistent delays
when under constant load. The new write throttle is based on the amount of
dirty data, rather than guesses about future performance of the system. When
there is a lot of dirty data, each transaction (e.g. write() syscall) will be
delayed by the same small amount. This eliminates the "brick wall of wait"
that the old write throttle could hit, causing all transactions to wait several
seconds until the next txg opens. One of the keys to the new write throttle is
decrementing the amount of dirty data as i/o completes, rather than at the end
of spa_sync(). Note that the write throttle is only applied once the i/o
scheduler is issuing the maximum number of outstanding async writes. See the
block comments in dsl_pool.c and above dmu_tx_delay() (reproduced below) for
more details.
This diff has several other effects, including:
* the commonly-tuned global variable zfs_vdev_max_pending has been removed;
use per-class zfs_vdev_*_max_active values or zfs_vdev_max_active instead.
* the size of each txg (meaning the amount of dirty data written, and thus the
time it takes to write out) is now controlled differently. There is no longer
an explicit time goal; the primary determinant is amount of dirty data.
Systems that are under light or medium load will now often see that a txg is
always syncing, but the impact to performance (e.g. read latency) is minimal.
Tune zfs_dirty_data_max and zfs_dirty_data_sync to control this.
* zio_taskq_batch_pct = 75 -- Only use 75% of all CPUs for compression,
checksum, etc. This improves latency by not allowing these CPU-intensive tasks
to consume all CPU (on machines with at least 4 CPU's; the percentage is
rounded up).
--matt
APPENDIX: problems with the current i/o scheduler
The current ZFS i/o scheduler (vdev_queue.c) is deadline based. The problem
with this is that if there are always i/os pending, then certain classes of
i/os can see very long delays.
For example, if there are always synchronous reads outstanding, then no async
writes will be serviced until they become "past due". One symptom of this
situation is that each pass of the txg sync takes at least several seconds
(typically 3 seconds).
If many i/os become "past due" (their deadline is in the past), then we must
service all of these overdue i/os before any new i/os. This happens when we
enqueue a batch of async writes for the txg sync, with deadlines 2.5 seconds in
the future. If we can't complete all the i/os in 2.5 seconds (e.g. because
there were always reads pending), then these i/os will become past due. Now we
must service all the "async" writes (which could be hundreds of megabytes)
before we service any reads, introducing considerable latency to synchronous
i/os (reads or ZIL writes).
Notes on porting to ZFS on Linux:
- zio_t gained new members io_physdone and io_phys_children. Because
object caches in the Linux port call the constructor only once at
allocation time, objects may contain residual data when retrieved
from the cache. Therefore zio_create() was updated to zero out the two
new fields.
- vdev_mirror_pending() relied on the depth of the per-vdev pending queue
(vq->vq_pending_tree) to select the least-busy leaf vdev to read from.
This tree has been replaced by vq->vq_active_tree which is now used
for the same purpose.
- vdev_queue_init() used the value of zfs_vdev_max_pending to determine
the number of vdev I/O buffers to pre-allocate. That global no longer
exists, so we instead use the sum of the *_max_active values for each of
the five I/O classes described above.
- The Illumos implementation of dmu_tx_delay() delays a transaction by
sleeping in condition variable embedded in the thread
(curthread->t_delay_cv). We do not have an equivalent CV to use in
Linux, so this change replaced the delay logic with a wrapper called
zfs_sleep_until(). This wrapper could be adopted upstream and in other
downstream ports to abstract away operating system-specific delay logic.
- These tunables are added as module parameters, and descriptions added
to the zfs-module-parameters.5 man page.
spa_asize_inflation
zfs_deadman_synctime_ms
zfs_vdev_max_active
zfs_vdev_async_write_active_min_dirty_percent
zfs_vdev_async_write_active_max_dirty_percent
zfs_vdev_async_read_max_active
zfs_vdev_async_read_min_active
zfs_vdev_async_write_max_active
zfs_vdev_async_write_min_active
zfs_vdev_scrub_max_active
zfs_vdev_scrub_min_active
zfs_vdev_sync_read_max_active
zfs_vdev_sync_read_min_active
zfs_vdev_sync_write_max_active
zfs_vdev_sync_write_min_active
zfs_dirty_data_max_percent
zfs_delay_min_dirty_percent
zfs_dirty_data_max_max_percent
zfs_dirty_data_max
zfs_dirty_data_max_max
zfs_dirty_data_sync
zfs_delay_scale
The latter four have type unsigned long, whereas they are uint64_t in
Illumos. This accommodates Linux's module_param() supported types, but
means they may overflow on 32-bit architectures.
The values zfs_dirty_data_max and zfs_dirty_data_max_max are the most
likely to overflow on 32-bit systems, since they express physical RAM
sizes in bytes. In fact, Illumos initializes zfs_dirty_data_max_max to
2^32 which does overflow. To resolve that, this port instead initializes
it in arc_init() to 25% of physical RAM, and adds the tunable
zfs_dirty_data_max_max_percent to override that percentage. While this
solution doesn't completely avoid the overflow issue, it should be a
reasonable default for most systems, and the minority of affected
systems can work around the issue by overriding the defaults.
- Fixed reversed logic in comment above zfs_delay_scale declaration.
- Clarified comments in vdev_queue.c regarding when per-queue minimums take
effect.
- Replaced dmu_tx_write_limit in the dmu_tx kstat file
with dmu_tx_dirty_delay and dmu_tx_dirty_over_max. The first counts
how many times a transaction has been delayed because the pool dirty
data has exceeded zfs_delay_min_dirty_percent. The latter counts how
many times the pool dirty data has exceeded zfs_dirty_data_max (which
we expect to never happen).
- The original patch would have regressed the bug fixed in
zfsonlinux/zfs@c418410, which prevented users from setting the
zfs_vdev_aggregation_limit tuning larger than SPA_MAXBLOCKSIZE.
A similar fix is added to vdev_queue_aggregate().
- In vdev_queue_io_to_issue(), dynamically allocate 'zio_t search' on the
heap instead of the stack. In Linux we can't afford such large
structures on the stack.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Ned Bass <bass6@llnl.gov>
Reviewed by: Brendan Gregg <brendan.gregg@joyent.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
http://www.illumos.org/issues/4045illumos/illumos-gate@69962b5647
Ported-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1913
3112 ztest does not honor ZFS_DEBUG
3113 ztest should use watchpoints to protect frozen arc bufs
3114 some leaked nvlists in zfsdev_ioctl
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Amdur <Matt.Amdur@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>
References:
https://www.illumos.org/issues/3112https://www.illumos.org/issues/3113https://www.illumos.org/issues/3114illumos/illumos-gate@cd1c8b85eb
The /proc/self/cmd watchpoint interface is specific to Solaris.
Therefore, the #3113 implementation was reworked to use the more
portable mprotect(2) system call. When the pages are watched they
are marked read-only for protection. Any write to the protected
address range immediately trigger a SIGSEGV. The pages are marked
writable again when they are unwatched.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
3582 zfs_delay() should support a variable resolution
3584 DTrace sdt probes for ZFS txg states
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Richard Elling <richard.elling@dey-sys.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/3582illumos/illumos-gate@0689f76
Ported by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Pavel Zakharov
Chris Williamson
Brian Behlendorf
Jason King
Ned Bass
Chunwei Chen
George Melikov
Don Brady
Chunwei Chen
Gvozden Neskovic
Hans Rosenfeld
Tom Caputi
Denys Rtveliashvili
Tony Hutter
Carlo Landmeter
Matthew Ahrens
Paul Dagnelie
Olaf Faaland
George Wilson
Prakash Surya
Tim Chase
Prakash Surya
Alec Salazar
Richard Yao
Michael Kjorling
Adam Leventhal