When --enable-asan is provided to configure then build all user
space components with fsanitize=address. For kernel support
use the Linux KASAN feature instead.
https://github.com/google/sanitizers/wiki/AddressSanitizer
When using gcc version 4.8 any test case which intentionally
generates a core dump will fail when using --enable-asan.
The default behavior is to disable core dumps and only newer
versions allow this behavior to be controled at run time with
the ASAN_OPTIONS environment variable.
Additionally, this patch includes some build system cleanup.
* Rules.am updated to set the minimum AM_CFLAGS, AM_CPPFLAGS,
and AM_LDFLAGS. Any additional flags should be added on a
per-Makefile basic. The --enable-debug and --enable-asan
options apply to all user space binaries and libraries.
* Compiler checks consolidated in always-compiler-options.m4
and renamed for consistency.
* -fstack-check compiler flag was removed, this functionality
is provided by asan when configured with --enable-asan.
* Split DEBUG_CFLAGS in to DEBUG_CFLAGS, DEBUG_CPPFLAGS, and
DEBUG_LDFLAGS.
* Moved default kernel build flags in to module/Makefile.in and
split in to ZFS_MODULE_CFLAGS and ZFS_MODULE_CPPFLAGS. These
flags are set with the standard ccflags-y kbuild mechanism.
* -Wframe-larger-than checks applied only to binaries or
libraries which include source files which are built in
both user space and kernel space. This restriction is
relaxed for user space only utilities.
* -Wno-unused-but-set-variable applied only to libzfs and
libzpool. The remaining warnings are the result of an
ASSERT using a variable when is always declared.
* -D_POSIX_PTHREAD_SEMANTICS and -D__EXTENSIONS__ dropped
because they are Solaris specific and thus not needed.
* Ensure $GDB is defined as gdb by default in zloop.sh.
Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7027
Occasionally observed failure of history_004_pos due to the test
case not being 100% reliable. In order to prevent false positives
disable this test case until it can be made reliable.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #7026Closes#7028
In ZFSOnLinux, our sources and build system are self contained such that
we do not need to make changes to the Linux kernel sources. Reiser4 on
the other hand exists solely as a kernel tree patch and opts to make
changes to the kernel rather than adapt to it. After Linux 4.1 made a
VFS change that replaced new_sync_read with do_sync_read, Reiser4's
maintainer decided to modify the kernel VFS to export the old function.
This caused our autotools check to misidentify the kernel API as
predating Linux 4.1 on kernels that have been patched with Reiser4
support, which breaks our build.
Reiser4 really should be patched to stop doing this, but lets modify our
check to be more strict to help the affected users of both filesystems.
Also, we were not checking the types of arguments and return value of
new_sync_read() and new_sync_write() . Lets fix that too.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#6241Closes#7021
As a performance optimization Lustre does not strictly update
the SA_ZPL_SIZE when adding/removing from non-directory entries.
This results in entries which cannot be removed through the ZPL
layer even though the ZAP is empty and safe to remove.
Resolve this issue by checking the zap_count() directly instead
on relying on the cached SA_ZPL_SIZE. Micro-benchmarks show no
significant performance impact due to the additional overhead
of using zap_count().
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7019
As part of the refactoring of ab9f4b0b82,
several uint64_t-s and uint8_t-s were changed to other types. This
caused ZoL github issue #6981, an overflow of a size_t on a 32-bit ARM
machine. In absense of any strong motivation for the type changes, this
simply puts them back, modulo the changes accumulated for ABD.
Compile-tested on amd64 and run-tested on armhf.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Closes#6981Closes#7023
Resolved unused variable warnings observed after restricting
-Wno-unused-but-set-variable to only libzfs and libzpool.
Reviewed-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6941
In ztest_verify_dnode_bt the ztest_object_lock must be held in
order to safely verify the unused bonus space.
Reviewed-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6941
kmem_alloc(0, ...) in userspace returns a leakable pointer.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Issue #6941
Replace "percent" with "%", add bold to default values.
Reviewed-by: bunder2015 <omfgbunder@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#7018
Attempt to reduce the number of comments posted by codecov
to PR requests. Based on the codecov documenation setting
"require_changes=yes" and "behavior=once" should result in
a single comment under most circumstances.
https://docs.codecov.io/v4.3.6/docs/pull-request-comments
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #7022Closes#7025
This fixes zhack's command processing on ARM. On ARM char
is unsigned, and so, in promotion to an int, it will never
compare equal to -1.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Closes#7016
When the compressed ARC feature was added in commit d3c2ae1
the method of reference counting in the ARC was modified. As
part of this accounting change the arc_buf_add_ref() function
was removed entirely.
This would have be fine but the arc_buf_add_ref() function
served a second undocumented purpose of updating the ARC access
information when taking a hold on a dbuf. Without this logic
in place a cached dbuf would not migrate its associated
arc_buf_hdr_t to the MFU list. This would negatively impact
the ARC hit rate, particularly on systems with a small ARC.
This change reinstates the missing call to arc_access() from
dbuf_hold() by implementing a new arc_buf_access() function.
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6171Closes#6852Closes#6989
When replacing a faulted device which was previously handled by a spare
multiple levels of nested interior VDEVs will be present in the pool
configuration; the following example illustrates one of the possible
situations:
NAME STATE READ WRITE CKSUM
testpool DEGRADED 0 0 0
raidz1-0 DEGRADED 0 0 0
spare-0 DEGRADED 0 0 0
replacing-0 DEGRADED 0 0 0
/var/tmp/fault-dev UNAVAIL 0 0 0 cannot open
/var/tmp/replace-dev ONLINE 0 0 0
/var/tmp/spare-dev1 ONLINE 0 0 0
/var/tmp/safe-dev ONLINE 0 0 0
spares
/var/tmp/spare-dev1 INUSE currently in use
This is safe and allowed, but get_replication() needs to handle this
situation gracefully to let zpool add new devices to the pool.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6678Closes#6996
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: John Kennedy <jwk404@gmail.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Prakash Surya <prakash.surya@delphix.com>
PROBLEM
=======
There's a race condition that exists if `zil_free_lwb` races with either
`zil_commit_waiter_timeout` and/or `zil_lwb_flush_vdevs_done`.
Here's an example panic due to this bug:
> ::status
debugging crash dump vmcore.0 (64-bit) from ip-10-110-205-40
operating system: 5.11 dlpx-5.2.2.0_2017-12-04-17-28-32b6ba51fb (i86pc)
image uuid: 4af0edfb-e58e-6ed8-cafc-d3e9167c7513
panic message:
BAD TRAP: type=e (#pf Page fault) rp=ffffff0010555970 addr=60 occurred in module "zfs" due to a NULL pointer dereference
dump content: kernel pages only
> $c
zio_shrink+0x12()
zil_lwb_write_issue+0x30d(ffffff03dcd15cc0, ffffff03e0730e20)
zil_commit_waiter_timeout+0xa2(ffffff03dcd15cc0, ffffff03d97ffcf8)
zil_commit_waiter+0xf3(ffffff03dcd15cc0, ffffff03d97ffcf8)
zil_commit+0x80(ffffff03dcd15cc0, 9a9)
zfs_write+0xc34(ffffff03dc38b140, ffffff0010555e60, 40, ffffff03e00fb758, 0)
fop_write+0x5b(ffffff03dc38b140, ffffff0010555e60, 40, ffffff03e00fb758, 0)
write+0x250(42, fffffd7ff4832000, 2000)
sys_syscall+0x177()
If there's an outstanding lwb that's in `zil_commit_waiter_timeout`
waiting to timeout, waiting on it's waiter's CV, we must be sure not to
call `zil_free_lwb`. If we end up calling `zil_free_lwb`, then that LWB
may be freed and can result in a use-after-free situation where the
stale lwb pointer stored in the `zil_commit_waiter_t` structure of the
thread waiting on the waiter's CV is used.
A similar situation can occur if an lwb is issued to disk, and thus in
the `LWB_STATE_ISSUED` state, and `zil_free_lwb` is called while the
disk is servicing that lwb. In this situation, the lwb will be freed by
`zil_free_lwb`, which will result in a use-after-free situation when the
lwb's zio completes, and `zil_lwb_flush_vdevs_done` is called.
This race condition is prevented in `zil_close` by calling `zil_commit`
before `zil_free_lwb` is called, which will ensure all outstanding (i.e.
all lwb's in the `LWB_STATE_OPEN` and/or `LWB_STATE_ISSUED` states)
reach the `LWB_STATE_DONE` state before the lwb's are freed
(`zil_commit` will not return untill all the lwb's are
`LWB_STATE_DONE`).
Further, this race condition is prevented in `zil_sync` by only calling
`zil_free_lwb` for lwb's that do not have their `lwb_buf` pointer set.
All lwb's not in the `LWB_STATE_DONE` state will have a non-null value
for this pointer; the pointer is only cleared in
`zil_lwb_flush_vdevs_done`, at which point the lwb's state will be
changed to `LWB_STATE_DONE`.
This race *is* present in `zil_suspend`, leading to this bug.
At first glance, it would appear as though this would not be true
because `zil_suspend` will call `zil_commit`, just like `zil_close`, but
the problem is that `zil_suspend` will set the zilog's `zl_suspend`
field prior to calling `zil_commit`. Further, in `zil_commit`, if
`zl_suspend` is set, `zil_commit` will take a special branch of logic
and use `txg_wait_synced` instead of performing the normal `zil_commit`
logic.
This call to `txg_wait_synced` might be good enough for the data to
reach disk safely before it returns, but it does not ensure that all
outstanding lwb's reach the `LWB_STATE_DONE` state before it returns.
This is because, if there's an lwb "stuck" in
`zil_commit_waiter_timeout`, waiting for it's lwb to timeout, it will
maintain a non-null value for it's `lwb_buf` field and thus `zil_sync`
will not free that lwb. Thus, even though the lwb's data is already on
disk, the lwb will be left lingering, waiting on the CV, and will
eventually timeout and be issued to disk even though the write is
unnecessary.
So, after `zil_commit` is called from `zil_suspend`, we incorrectly
assume that there are not outstanding lwb's, and proceed to free all
lwb's found on the zilog's lwb list. As a result, we free the lwb that
will later be used `zil_commit_waiter_timeout`.
SOLUTION
========
The solution to this, is to ensure all outstanding lwb's complete before
calling `zil_free_lwb` via `zil_destroy` in `zil_suspend`. This patch
accomplishes this goal by forcing the normal `zil_commit` logic when
called from `zil_sync`.
Now, `zil_suspend` will call `zil_commit_impl` which will always use the
normal logic of waiting/issuing lwb's to disk before it returns. As a
result, any lwb's outstanding when `zil_commit_impl` is called will be
guaranteed to reach the `LWB_STATE_DONE` state by the time it returns.
Further, no new lwb's will be created via `zil_commit` since the zilog's
`zl_suspend` flag will be set. This will force all new callers of
`zil_commit` to use `txg_wait_synced` instead of creating and issuing
new lwb's.
Thus, all lwb's left on the zilog's lwb list when `zil_destroy` is
called will be in the `LWB_STATE_DONE` state, and we'll avoid this race
condition.
OpenZFS-issue: https://www.illumos.org/issues/8909
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ece62b6f8dCloses#6940
Our zfs backed Lustre MDT had soft lockups while under heavy metadata
workloads while handling transaction callbacks from osd_zfs.
The problem is zfs is not taking advantage of the fast path in
Lustre's trans callback handling, where Lustre will skip the calls
to ptlrpc_commit_replies() when it already saw a higher transaction
number.
This patch corrects this, it also has a positive impact on metadata
performance on Lustre with osd_zfs, plus some cleanup in the headers.
A similar issue for ext4/ldiskfs is described on:
https://jira.hpdd.intel.com/browse/LU-6527
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Li Dongyang <dongyang.li@anu.edu.au>
Closes#6986
This patch simply removes 2 empty files that were accidentally
added a part of the scrub priority patch.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6990
When sequential scrubs were merged, all calls to arc_read()
(including prefetch IOs) were given ZIO_PRIORITY_ASYNC_READ.
Unfortunately, this behaves badly with an existing issue where
prefetch IOs cannot be re-prioritized after the issue. The
result is that synchronous reads end up in the same vdev_queue
as the scrub IOs and can have (in some workloads) multiple
seconds of latency.
This patch incorporates 2 changes. The first ensures that all
scrub IOs are given ZIO_PRIORITY_SCRUB to allow the vdev_queue
code to differentiate between these I/Os and user prefetches.
Second, this patch introduces zio_change_priority() to provide
the missing capability to upgrade a zio's priority.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6921Closes#6926
This extends vdev_id to support a new slot type, ses, for SCSI Enclosure
Services. With slot type ses, the disk slot numbers are determined by
using the device slot number reported by sg_ses for the device with
matching SAS address, found by querying all available enclosures.
This is primarily of use on systems with a deficient driver omitting
support for bay_identifier in /sys/devices. In my testing, I found that
the existing slot types of port and id were not stable across disk
replacement, so an alternative was required.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Simon Guest <simon.guest@tesujimath.org>
Closes#6956
Using a command similar to 'arc_summary.py | head' causes
a broken pipe exception. Gracefully exit in the case of a
broken pipe in arc_summary.py.
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes#6965Closes#6969
If an invalid option is provided to arc_summary.py we handle any error
thrown from the getopt Python module and print the usage help message.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6983
Authored by: Dominik Hassler <hadfl@omniosce.org>
Reviewed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/8794
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/578f67364cCloses#6973
The function that fills the uberblock ring buffer on every device label
has been reworked to avoid occasional failures caused by a race
condition that prevents 'zpool sync' from writing some uberblock
sequentially: this happens when the pool sync ioctl dispatch code calls
txg_wait_synced() while we're already waiting for a TXG to sync.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6924Closes#6977
When the multihost property is enabled it should be impossible to
import an active pool even using the force (-f) option. This patch
prevents a forced import from succeeding when importing with a
stale cache file.
The root cause of the problem is that the kernel modules trusted
the hostid provided in configuration. This is always correct when
the configuration is generated by scanning for the pool. However,
when using an existing cache file the hostid could be stale which
would result in the activity check being skipped.
Resolve the issue by always using the hostid read from the label
configuration where the best uberblock was found.
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6933Closes#6971
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6962
These changes propagate the "--with-systemd" configure option to the
RPM spec file, allowing Debian-based distributions to package
systemd-related files.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6591Closes#6963
The functionality provided by this header is not required by any
of the ZFS user space code. Minimal functionality was provided
in commit c28a677 which added include/sys/frame.h.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6960Closes#6972
Enable QAT accelerated gzip compression in zfs-dkms RPM package when
environment variant ICP_ROOT is set to QAT drive source code folder
and QAT hardware presence. Otherwise, use default gzip compression.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: David Qian <david.qian@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6932
Add missing zfs-import.target to list of systemd services in zfs
RPM spec file.
Reviewed-by: Niklas Wagner <Skaro@Skaronator.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ralf Ertzinger <ralf@skytale.net>
Issue #6953Closes#6955
* Teach ZED to handle spares usingi the configured ashift: if the zpool
'ashift' property is set then ZED should use its value when kicking
in a hotspare; with this change 512e disks can be used as spares
for VDEVs that were created with ashift=9, even if ZFS natively
detects them as 4K block devices.
* Introduce an additional auto_spare test case which verifies that in
the face of multiple device failures an appropiate number of spares
are kicked in.
* Fix zed_stop() in "libtest.shlib" which did not correctly wait the
target pid.
* Fix ZED crashing on startup caused by a race condition in libzfs
when used in multi-threaded context.
* Convert ZED over to using the tpool library which is already present
in the Illumos FMA code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#2562Closes#6858
Occasionally observed failure of vdev_zaps_004_pos due to the test
case not being 100% reliable. In order to prevent false positives
disable this test case until it can be made reliable.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #6935Closes#6936
Suppress incorrect warnings from versions of objtool which are not
aware of x86 EVEX prefix instructions used for AVX512.
module/zfs/vdev_raidz_math_avx512bw.o: warning:
objtool: <func+offset>: can't find jump dest instruction at .text
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6928
Fix a segfault when running 'zpool iostat -v 1' while adding
a VDEV.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#6748Closes#6872
This is a purely cosmetic change. The zilog's "zl_writer_lock" field is
being renamed to "zl_issuer_lock" to try and make the code easier to
understand; no other changes are made.
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: C Fraire <cfraire@me.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/8603
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/2daf06546bCloses#6927
Occasionally observed failure of create-o_ashift due to the test
case not being 100% reliable. In order to prevent false positives
disable this test case until it can be made reliable.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #6924Closes#6925
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Prakash Surya <prakash.surya@delphix.com>
Problem
=======
The current implementation of zil_commit() can introduce significant
latency, beyond what is inherent due to the latency of the underlying
storage. The additional latency comes from two main problems:
1. When there's outstanding ZIL blocks being written (i.e. there's
already a "writer thread" in progress), then any new calls to
zil_commit() will block waiting for the currently oustanding ZIL
blocks to complete. The blocks written for each "writer thread" is
coined a "batch", and there can only ever be a single "batch" being
written at a time. When a batch is being written, any new ZIL
transactions will have to wait for the next batch to be written,
which won't occur until the current batch finishes.
As a result, the underlying storage may not be used as efficiently
as possible. While "new" threads enter zil_commit() and are blocked
waiting for the next batch, it's possible that the underlying
storage isn't fully utilized by the current batch of ZIL blocks. In
that case, it'd be better to allow these new threads to generate
(and issue) a new ZIL block, such that it could be serviced by the
underlying storage concurrently with the other ZIL blocks that are
being serviced.
2. Any call to zil_commit() must wait for all ZIL blocks in its "batch"
to complete, prior to zil_commit() returning. The size of any given
batch is proportional to the number of ZIL transaction in the queue
at the time that the batch starts processing the queue; which
doesn't occur until the previous batch completes. Thus, if there's a
lot of transactions in the queue, the batch could be composed of
many ZIL blocks, and each call to zil_commit() will have to wait for
all of these writes to complete (even if the thread calling
zil_commit() only cared about one of the transactions in the batch).
To further complicate the situation, these two issues result in the
following side effect:
3. If a given batch takes longer to complete than normal, this results
in larger batch sizes, which then take longer to complete and
further drive up the latency of zil_commit(). This can occur for a
number of reasons, including (but not limited to): transient changes
in the workload, and storage latency irregularites.
Solution
========
The solution attempted by this change has the following goals:
1. no on-disk changes; maintain current on-disk format.
2. modify the "batch size" to be equal to the "ZIL block size".
3. allow new batches to be generated and issued to disk, while there's
already batches being serviced by the disk.
4. allow zil_commit() to wait for as few ZIL blocks as possible.
5. use as few ZIL blocks as possible, for the same amount of ZIL
transactions, without introducing significant latency to any
individual ZIL transaction. i.e. use fewer, but larger, ZIL blocks.
In theory, with these goals met, the new allgorithm will allow the
following improvements:
1. new ZIL blocks can be generated and issued, while there's already
oustanding ZIL blocks being serviced by the storage.
2. the latency of zil_commit() should be proportional to the underlying
storage latency, rather than the incoming synchronous workload.
Porting Notes
=============
Due to the changes made in commit 119a394ab0, the lifetime of an itx
structure differs than in OpenZFS. Specifically, the itx structure is
kept around until the data associated with the itx is considered to be
safe on disk; this is so that the itx's callback can be called after the
data is committed to stable storage. Since OpenZFS doesn't have this itx
callback mechanism, it's able to destroy the itx structure immediately
after the itx is committed to an lwb (before the lwb is written to
disk).
To support this difference, and to ensure the itx's callbacks can still
be called after the itx's data is on disk, a few changes had to be made:
* A list of itxs was added to the lwb structure. This list contains
all of the itxs that have been committed to the lwb, such that the
callbacks for these itxs can be called from zil_lwb_flush_vdevs_done(),
after the data for the itxs is committed to disk.
* A list of itxs was added on the stack of the zil_process_commit_list()
function; the "nolwb_itxs" list. In some circumstances, an itx may
not be committed to an lwb (e.g. if allocating the "next" ZIL block
on disk fails), so this list is used to keep track of which itxs
fall into this state, such that their callbacks can be called after
the ZIL's writer pipeline is "stalled".
* The logic to actually call the itx's callback was moved into the
zil_itx_destroy() function. Since all consumers of zil_itx_destroy()
were effectively performing the same logic (i.e. if callback is
non-null, call the callback), it seemed like useful code cleanup to
consolidate this logic into a single function.
Additionally, the existing Linux tracepoint infrastructure dealing with
the ZIL's probes and structures had to be updated to reflect these code
changes. Specifically:
* The "zil__cw1" and "zil__cw2" probes were removed, so they had to be
removed from "trace_zil.h" as well.
* Some of the zilog structure's fields were removed, which affected
the tracepoint definitions of the structure.
* New tracepoints had to be added for the following 3 new probes:
* zil__process__commit__itx
* zil__process__normal__itx
* zil__commit__io__error
OpenZFS-issue: https://www.illumos.org/issues/8585
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/5d95a3aCloses#6566
When zfs_sticky_remove_access() was originally adapted for Linux
a typo was made which altered the intended behavior. As described
in the block comment, the intended behavior is that permission
should be granted when the entry is a regular file and you have
write access. That is, S_ISREG should have been used instead of
S_ISDIR.
Restricting permission to regular files made good sense for older
systems where setting the bit on executable files would instruct
the system to save the program's text segment on the swap device.
On modern systems this behavior has been replaced by the sticky
bit acting as a restricted deletion flag and the plain file
restriction has been relaxed.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6889Closes#6910
5dc1ff29 changed the user space program to mount a zfs snapshot
from /bin/sh to /usr/bin/env. If the executable is not present
in the initramfs then snapshots cannot be automounted.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: James Dingwall <james.dingwall@zynstra.com>
Closes#5360Closes#6913
When the pool configuration contains a hole due to a previous device
removal ignore this top level vdev. Failure to do so will result in
the current configuration being assessed to have a non-uniform
replication level and the expected warning will be disabled.
The zpool_add_010_pos test case was extended to cover this scenario.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6907Closes#6911
Using zio_data_buf_alloc() to allocate the itx's may be unsafe
because the itx->itx_lr.lrc_reclen field is not constant from
allocation to free. Using a different itx->itx_lr.lrc_reclen
size in zio_data_buf_free() can result in the allocation being
returned to the wrong kmem cache.
This issue can be avoided entirely by storing the allocation size
in itx->itx_size and using that for zio_data_buf_free().
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6912
When d4a72f23 was merged, pss_pass_issued was incorrectly
added to the middle of the pool_scan_stat_t structure
instead of the end. This patch simply corrects this issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6909
Fix a regression accidentally introduced in 1b81ab4 that prevents
'zfs get {user|group}objused@' from correctly reporting the requested
value.
Update "userspace_003_pos.ksh" and "groupspace_003_pos.ksh" to verify
this functionality.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#6908
Fix build errors with gcc 7.2.0 on Gentoo with kernel 4.14
built with CONFIG_GCC_PLUGIN_RANDSTRUCT=y such as:
module/nvpair/nvpair.c:2810:2:error:
positional initialization of field in ?struct? declared with
'designated_init' attribute [-Werror=designated-init]
nvs_native_nvlist,
^~~~~~~~~~~~~~~~~
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mark Wright <gienah@gentoo.org>
Closes#5390Closes#6903
The initramfs script was not honoring canmount=off. With this change,
it does. If the administrator has asked that a filesystem not be
mounted, that should be honored.
As an exception, the initramfs script ignores canmount=off on the
rootfs. The rootfs should not have canmount=off set either. However,
mounting it anyway seems harmless because it is being asked for
explicitly. The point of this exception is to avoid the risk of
breaking existing systems, just in case someone has canmount=off set on
their rootfs.
The initramfs still mounts filesystems with canmount=noauto. This is
necessary because it is typical to set that on the rootfs so that it can
be cloned. Without canmount=noauto, the clones' duplicate mountpoints
would conflict.
This is the remainder of the fix for:
https://github.com/zfsonlinux/pkg-zfs/issues/221
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#6897
For filesystems that are children of the rootfs, when mountpoint=none or
mountpoint=legacy, the initrafms script would assume a mountpoint based
on the dataset path. Given that the rootfs should have mountpoint=/ and
mountpoint inheritance is is the default behavior of ZFS, this behavior
seems unnecessary. In any event, it turns mountpoint=none into a no-op.
That removes this option from the administrator, and if someone uses it,
it does not work as expected. Worse yet, if the mountpoint directory
does not exist (which is the typical case for mountpoint=none), the
mounting and thus the boot process will fail. For the case of
mountpoint=legacy, the assumed mountpoint may not be the correct value
set in /etc/fstab.
This change makes the initramfs script not mount the filesystem in
either case. For mountpoint=none, this means we are correctly honoring
the setting. For mountpoint=legacy, there are two scenarios: If
canmount=on, the filesystem will be mounted by the normal mechanisms
later in the boot process. If canmount=noauto, the filesystem will not
be mounted at all, unless the administrator has done something special.
If they're not doing something special and they want it mounted by the
initramfs, they can simply not set mountpoint=legacy.
This is part of the fix for:
https://github.com/zfsonlinux/pkg-zfs/issues/221
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#6897
Resolve new warnings and errors from cppcheck v1.80.
* [lib/libshare/libshare.c:543]: (warning)
Possible null pointer dereference: protocol
* [lib/libzfs/libzfs_dataset.c:2323]: (warning)
Possible null pointer dereference: srctype
* [lib/libzfs/libzfs_import.c:318]: (error)
Uninitialized variable: link
* [module/zfs/abd.c:353]: (error) Uninitialized variable: sg
* [module/zfs/abd.c:353]: (error) Uninitialized variable: i
* [module/zfs/abd.c:385]: (error) Uninitialized variable: sg
* [module/zfs/abd.c:385]: (error) Uninitialized variable: i
* [module/zfs/abd.c:553]: (error) Uninitialized variable: i
* [module/zfs/abd.c:553]: (error) Uninitialized variable: sg
* [module/zfs/abd.c:763]: (error) Uninitialized variable: i
* [module/zfs/abd.c:763]: (error) Uninitialized variable: sg
* [module/zfs/abd.c:305]: (error) Uninitialized variable: tmp_page
* [module/zfs/zpl_xattr.c:342]: (warning)
Possible null pointer dereference: value
* [module/zfs/zvol.c:208]: (error) Uninitialized variable: p
Convert the following suppression to inline.
* [module/zfs/zfs_vnops.c:840]: (error)
Possible null pointer dereference: aiov
Exclude HAVE_UIO_ZEROCOPY and HAVE_DNLC from analysis since
these macro's will never be defined until this functionality
is implemented.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#6879
Display correct data from kstat arcstats for evict_skips,
which is currently repeating the data from mutex_misses.
Fixes#6882
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Scot W. Stevenson <scot.stevenson@gmail.com>
Closes#6882Closes#6883
