This fixes -Wsingle-bit-bitfield-constant-conversion warning from
clang-16 like:
lib/libzfs/libzfs_dataset.c:4529:19: error: implicit truncation
from 'int' to a one-bit wide bit-field changes value from
1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
flags.nounmount = B_TRUE;
^ ~~~~~~
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14125
* The complaint in ztest_replay_write() is only possible if something
went horribly wrong. An assertion will silence this and if it goes
off, we will know that something is wrong.
* The complaint in spa_estimate_metaslabs_to_flush() is not impossible,
but seems very unlikely. We resolve this by passing the value from
the `MIN()` that does not go to infinity when the variable is zero.
There was a third report from Clang's scan-build, but that was a
definite false positive and disappeared when checked again through
Clang's static analyzer with Z3 refution via CodeChecker.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14124
uu_avl and uu_list stored internal next/prev pointers and parent
pointers (unused) obfuscated (byte swapped) to hide them from a long
forgotten leak checker (No one at the 2022 OpenZFS developers meeting
could recall the history.) This would break on CHERI systems and adds
no obvious value. Rename the members, use proper types rather than
uintptr_t, and eliminate the related macros.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14126
Commit 68ddc06b61 introduced support
for receiving unencrypted datasets as children of encrypted ones but
unfortunately got the logic upside down. This resulted in failing to
deny receives of incremental sends into encrypted datasets without
their keys loaded. If receiving a filesystem, the receive was done
into a newly created unencrypted child dataset of the target. In
case of volumes the receive made the target volume undeletable since
a dataset was created below it, which we obviously can't handle.
Incremental streams with embedded blocks are affected as well.
We fix the broken logic to properly deny receives in such cases.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#13598Closes#14055Closes#14119
Don't assume size_t can carry pointer provenance and use uintptr_t
(identialy on all current platforms) instead.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14131
Cast the integer type to (u)intptr_t before casting to "void *". In
CHERI C/C++ we warn on bare casts from integers to pointers to catch
attempts to create pointers our of thin air. We allow the warning to be
supressed with a suitable cast through (u)intptr_t.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14131
Avoid assuming than a uint64_t can hold a pointer.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14131
Avoid assuming than a uint64_t can hold a pointer and reduce the
number of casts in the process.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14131
Avoid assuming that a pointer can fit in a uint64_t and use uintptr_t
instead.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14131
Nothing consumes this definition so stop defining it.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14128
Check __riscv_xlen == 64 rather than _LP64 and define _LP64 if missing.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#14128
kmem_scnprintf() is only available in libzpool. Recent buildbot issues
with showing FreeBSD results kept us from seeing this before
97143b9d31 was merged.
The code has been changed to sanitize the output from `kmem_scnprintf()`.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14111
If a user that uses systemd and dracut wants to overide certain
settings, they typically use `systemctl edit [unit]` or place a file in
`/etc/systemd/system/[unit].d/override.conf` directly.
The zfs-dracut module did not include those overrides however, so this
did not have any effect at boot time.
For zfs-import-scan.service and zfs-import-cache.service, overrides are
now included in the dracut initramfs image.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Vince van Oosten <techhazard@codeforyouand.me>
Closes#14075Closes#14076
Rather than panic debug builds when we fail to parse a whole ZIL, let's
instead improve the logging of errors and continue like in a release
build.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#14116
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14113
4170ae4ea6 was intended to tackle TOCTOU
race conditions reported by CodeQL, but as an oversight, a file
descriptor was not closed and some comments were not updated.
Interestingly, CodeQL did not complain about the file descriptor leak,
so there is room for improvement in how we configure it to try to detect
this issue so that we get early warning about this.
In addition, an optimization opportunity was missed by mistake in
lib/libshare/os/linux/smb.c, which prevented us from truly closing the
TOCTOU race. This was also caught by Coverity.
Reported-by: Coverity (CID 1524424)
Reported-by: Coverity (CID 1526804)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14109
Check for cr == NULL before dereferencing it in
dsl_enforce_ds_ss_limits() to lookup the zone/jail ID.
Reported-by: Coverity (CID 1210459)
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#14103
`snprintf()` is meant to protect against buffer overflows, but operating
on the buffer using its return value, possibly by calling it again, can
cause a buffer overflow, because it will return how many characters it
would have written if it had enough space even when it did not. In a
number of places, we repeatedly call snprintf() by successively
incrementing a buffer offset and decrementing a buffer length, by its
return value. This is a potentially unsafe usage of `snprintf()`
whenever the buffer length is reached. CodeQL complained about this.
To fix this, we introduce `kmem_scnprintf()`, which will return 0 when
the buffer is zero or the number of written characters, minus 1 to
exclude the NULL character, when the buffer was too small. In all other
cases, it behaves like snprintf(). The name is inspired by the Linux and
XNU kernels' `scnprintf()`. The implementation was written before I
thought to look at `scnprintf()` and had a good name for it, but it
turned out to have identical semantics to the Linux kernel version.
That lead to the name, `kmem_scnprintf()`.
CodeQL only catches this issue in loops, so repeated use of snprintf()
outside of a loop was not caught. As a result, a thorough audit of the
codebase was done to examine all instances of `snprintf()` usage for
potential problems and a few were caught. Fixes for them are included in
this patch.
Unfortunately, ZED is one of the places where `snprintf()` is
potentially used incorrectly. Since using `kmem_scnprintf()` in it would
require changing how it is linked, we modify its usage to make it safe,
no matter what buffer length is used. In addition, there was a bug in
the use of the return value where the NULL format character was not
being written by pwrite(). That has been fixed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14098
Assertions are meant to check assumptions, but the way that this
assertion is written does not check an assumption, since it is provably
always true. Removing the assertion will cause a compiler warning (made
into an error by -Werror) about printing up to 512 bytes to a 256-byte
buffer, so instead, we change the assertion to verify the assumption
that we never do a snprintf() that is truncated to avoid overrunning the
256-byte buffer.
This was caught by an audit of the codebase to look for misuse of
`snprintf()` after CodeQL reported that we had misused `snprintf()`. An
explanation of how snprintf() can be misused is here:
https://www.redhat.com/en/blog/trouble-snprintf
This particular instance did not misuse `snprintf()`, but it was caught
by the audit anyway.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14098
CodeQL reported that when the VERIFY3U condition is false, we do not
pass enough arguments to `spl_panic()`. This is because the format
string from `snprintf()` was concatenated into the format string for
`spl_panic()`, which causes us to have an unexpected format specifier.
A CodeQL developer suggested fixing the macro to have a `%s` format
string that takes a stringified RIGHT argument, which would fix this.
However, upon inspection, the VERIFY3U check was never necessary in the
first place, so we remove it in favor of just calling `snprintf()`.
Lastly, it is interesting that every other static analyzer run on the
codebase did not catch this, including some that made an effort to catch
such things. Presumably, all of them relied on header annotations, which
we have not yet done on `spl_panic()`. CodeQL apparently is able to
track the flow of arguments on their way to annotated functions, which
llowed it to catch this when others did not. A future patch that I have
in development should annotate `spl_panic()`, so the others will catch
this too.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14098
CodeQL and Coverity both complained about:
* lib/libshare/os/linux/smb.c
* tests/zfs-tests/cmd/mmapwrite.c
* twice
* tests/zfs-tests/tests/functional/tmpfile/tmpfile_002_pos.c
* tests/zfs-tests/tests/functional/tmpfile/tmpfile_stat_mode.c
* coverity had a second complaint that CodeQL did not have
* tests/zfs-tests/cmd/suid_write_to_file.c
* Coverity had two complaints and CodeQL had one complaint, both
differed. The CodeQL complaint is about the main point of the
test, so it is not fixable without a hack involving `fork()`.
The issues reported by CodeQL are fixed, with the exception of the last
one, which is deemed to be a false positive that is too much trouble to
wrokaround. The issues reported by Coverity were only fixed if CodeQL
complained about them.
There were issues reported by Coverity in a number of other files that
were not reported by CodeQL, but fixing the CodeQL complaints is
considered a priority since we want to integrate it into a github
workflow, so the remaining Coverity complaints are left for future work.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14098
This reverts commit fb823de9f due to a regression. It is in fact possible
for the range->eos_marker to be false on error.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #14042Closes#14104
The previous version reported all the right info, but the VERIFY3 name
made a little more confusing when looking for the matching location in
the source code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Rob N ★ <robn@despairlabs.com>
Closes#14099
This patch relax the quota limitation for dataset by around 3%.
What this means is that user can write more data then the quota is
set to. However thanks to that we can get more stable bandwidth, in
case when we are overwriting data in-place, and not consuming any
additional space.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mariusz Zaborski <oshogbo@vexillium.org>
Sponsored-by: Zededa Inc.
Sponsored-by: Klara Inc.
Closes#13839
Reclaim metadata when arc_available_memory < 0 even if
meta_used is not bigger than arc_meta_limit.
As described in https://github.com/openzfs/zfs/issues/14054 if
zfs_arc_meta_limit_percent=100 then ARC target can collapse to
arc_min due to arc_purge not freeing any metadata.
This patch lets arc_prune to do its work when arc_available_memory
is negative even if meta_used is not bigger than arc_meta_limit,
avoiding ARC target collapse.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gionatan Danti <g.danti@assyoma.it>
Closes#14054Closes#14093
The autotrim thread only reads zfs_trim_extent_bytes_min and
zfs_trim_extent_bytes_max variable only on thread start. We
should check for parameter changes during thread execution to
allow parameter changes take effect without needing to disable
then restart the autotrim.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Václav Skála <skala@vshosting.cz>
Closes#14077
Implement support for Linux's RENAME_* flags (for renameat2). Aside from
being quite useful for userspace (providing race-free ways to exchange
paths and implement mv --no-clobber), they are used by overlayfs and are
thus required in order to use overlayfs-on-ZFS.
In order for us to represent the new renameat2(2) flags in the ZIL, we
create two new transaction types for the two flags which need
transactional-level support (RENAME_EXCHANGE and RENAME_WHITEOUT).
RENAME_NOREPLACE does not need any ZIL support because we know that if
the operation succeeded before creating the ZIL entry, there was no file
to be clobbered and thus it can be treated as a regular TX_RENAME.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Snajdr <snajpa@snajpa.net>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Closes#12209Closes#14070
This is in preparation for RENAME_EXCHANGE and RENAME_WHITEOUT support
for ZoL, but the changes here allow for far nicer fallbacks than the
previous implementation (the source and target are re-linked in case of
the final link failing).
In addition, a small cleanup was done for the "target exists but is a
different type" codepath so that it's more understandable.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Closes#12209Closes#14070
This allows for much cleaner VERIFY-level assertions.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Closes#14070
Open files, which aren't present in the snapshot, which is being
roll-backed to, need to disappear from the visible VFS image of
the dataset.
Kernel provides d_drop function to drop invalid entry from
the dcache, but inode can be referenced by dentry multiple dentries.
The introduced zpl_d_drop_aliases function walks and invalidates
all aliases of an inode.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes#9600Closes#14070
This fixes the instances of the "Multiplication result converted to
larger type" alert that codeQL scanning found.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Andrew Innes <andrew.c12@gmail.com>
Closes#14094
Follow up for 4938d01d which changed zio_flag from enum to uint64_t.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14100
Even when only building kmods process the scripts directory. This
way the common.sh script will be generated and the zfs.sh script
can be used to load/unload the in-tree kernel modules.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes#14027Closes#14051
Currently, the Debian packages are generated from ALIEN that converts
RPMs to Debian packages. This commit adds native Debian packaging for
Debian based systems.
This packaging is a fork of Debian zfs-linux 2.1.6-2 release.
(source: https://salsa.debian.org/zfsonlinux-team/zfs)
Some updates have been made to keep the footprint minimal that
include removing the tests, translation files, patches directory etc.
All credits go to Debian ZFS on Linux Packaging Team.
For copyright information, please refer to contrib/debian/copyright.
scripts/debian-packaging.sh can be used to invoke the build.
Reviewed-by: Mo Zhou <cdluminate@gmail.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#13451
We ran out of space in enum zio_flag for additional flags. Rather than
introduce enum zio_flag2 and then modify a bunch of functions to take a
second flags variable, we expand the type to 64 bits via `typedef
uint64_t zio_flag_t`.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Co-authored-by: Richard Yao <richard.yao@klarasystems.com>
Closes#14086
CodeQL is a static analyzer from github with a very low false positive
rate. We have long wanted to have static analysis runs done on every
pull request and using CodeQL, we can.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Andrew Innes <andrew.c12@gmail.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14087
Windows port frees memory that was alloc'd aligned in a different way
then alloc'd memory. So changing frees to be specific.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrew Innes <andrew.c12@gmail.com>
Co-Authored-By: Jorgen Lundman <lundman@lundman.net>
Closes#14059
vm_object_page_clean() expects that the associated vnode is locked
as VOP_PUTPAGES() may get called on the vnode.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Closes#14079
The use of __noreturn__ in 55d7afa4ad on
spl_panic() caused objtool warnings on Linux when the kernel is built
with CONFIG_STACK_VALIDATION=y. This patch works around that by
restricting the application of __noreturn__ to builds for static
analyzers.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14068
Update the META file to reflect compatibility with the 6.0 kernel.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14091
zed aborts and dumps core in vdev_whole_disk_from_config() if
wholedisk property does not exist. make_leaf_vdev() adds the
property but there may be already pools that don't have the
wholedisk in the label.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#14062
As investigated by #14026, the zpool_add_004_pos can reliably hang if
the timing is not right. This is caused by a race condition between
zed doing zpool reopen (due to the zvol being added to the zpool),
and the command zpool destroy.
This change adds a delay between zpool add zvol and zpool destroy to
avoid these issue, but does not address the underlying problem.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Issue #14026Closes#14052
Coverity made two complaints about this function. The first is that we
ignore the number of bytes read. The second is that we have a sizeof
mismatch.
On 64-bit systems, long is a 64-bit type. Paradoxically, the standard
says that hostid is 32-bit, yet is also a long type. On 64-bit big
endian systems, reading into the long would cause us to return 0 as our
hostid after the mask. This is wrong.
Also, if a partial read were to happen (it should not), we would return
a partial hostid, which is also wrong.
We introduce a uint32_t system_hostid stack variable and ensure that the
read is done into it and check the read's return value. Then we set the
value based on whether the read was successful. This should fix both of
coverity's complaints.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13968
2a068a1394 introduced 2 new defect
reports from Coverity and 1 from Clang's static analyzer.
Coverity complained about a potential resource leak from only calling
`close(fd)` when `fd > 0` because `fd` might be `0`. This is a false
positive, but rather than dismiss it as such, we can change the
comparison to ensure that this never appears again from any static
analyzer. Upon inspection, 6 more instances of this were found in the
file, so those were changed too. Unfortunately, since the file
descriptor has been put into an unsigned variable in `attr.userns_fd`,
we cannot do a non-negative check on it to see if it has not been
allocated, so we instead restructure the error handling to avoid the
need for a check. This also means that errors had not been handled
correctly here, so the static analyzer found a bug (although practically
by accident).
Coverity also complained about a dereference before a NULL check in
`do_idmap_mount()` on `source`. Upon inspection, it appears that the
pointer is never NULL, so we delete the NULL check as cleanup.
Clang's static analyzer complained that the return value of
`write_pid_idmaps()` can be uninitialized if we have no idmaps to write.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14061
The motivation for upgrading our PRNG is the recent buildbot failures in
the ZTS' tests/functional/fault/decompress_fault test. The probability
of a failure in that test is 0.8^256, which is ~1.6e-25 out of 1, yet we
have observed multiple test failures in it. This suggests a problem with
our random number generation.
The xorshift128+ generator that we were using has been replaced by newer
generators that have "better statistical properties". After doing some
reading, it turns out that these generators have "low linear complexity
of the lowest bits", which could explain the ZTS test failures.
We do two things to try to fix this:
1. We upgrade from xorshift128+ to xoshiro256++ 1.0.
2. We tweak random_get_pseudo_bytes() to copy the higher order
bytes first.
It is hoped that this will fix the test failures in
tests/functional/fault/decompress_fault, although I have not done
simulations. I am skeptical that any simulations I do on a PRNG with a
period of 2^256 - 1 would be meaningful.
Since we have raised the minimum kernel version to 3.10 since this was
first implemented, we have the option of using the Linux kernel's
get_random_int(). However, I am not currently prepared to do performance
tests to ensure that this would not be a regression (for the time
being), so we opt for upgrading our PRNG to a newer one from Sebastiano
Vigna.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13983
Microzap on-disk format does not include a hash tree, expecting one to
be built in RAM during mzap_open(). The built tree is linked to DMU
user buffer, freed when original DMU buffer is dropped from cache. I've
found that workloads accessing many large directories and having active
eviction from DMU cache spend significant amount of time building and
then destroying the trees. I've also found that for each 64 byte mzap
element additional 64 byte tree element is allocated, that is a waste
of memory and CPU caches.
Improve memory efficiency of the hash tree by switching from AVL-tree
to B-tree. It allows to save 24 bytes per element just on pointers.
Save 32 bits on mze_hash by storing only upper 32 bits since lower 32
bits are always zero for microzaps. Save 16 bits on mze_chunkid, since
microzap can never have so many elements. Respectively with the 16 bits
there can be no more than 16 bits of collision differentiators. As
result, struct mzap_ent now drops from 48 (rounded to 64) to 8 bytes.
Tune B-trees for small data. Reduce BTREE_CORE_ELEMS from 128 to 126
to allow struct zfs_btree_core in case of 8 byte elements to pack into
2KB instead of 4KB. Aside of the microzaps it should also help 32bit
range trees. Allow custom B-tree leaf size to reduce memmove() time.
Split zap_name_alloc() into zap_name_alloc() and zap_name_init_str().
It allows to not waste time allocating/freeing memory when processing
multiple names in a loop during mzap_open().
Together on a pool with 10K directories of 1800 files each and DMU
cache limited to 128MB this reduces time of `find . -name zzz` by 41%
from 7.63s to 4.47s, and saves additional ~30% of CPU time on the DMU
cache reclamation.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14039
The ifdef used would never work because the CPP is not aware of C
structure definitions. Rather than use an autotools check, we can just
use a nameless structure that we typedef to mount_attr_t. This is a
Linux kernel interface, which means that it is stable and this is fine
to do.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14057Closes#14058
a6ccb36b94 had been intended to include
this to silence Coverity reports, but this one was missed by mistake.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14043
