Commit Graph

2777 Commits

Author SHA1 Message Date
Ryan Moeller
748b9d5bda
zil: Relax assertion in zil_parse
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
2022-11-01 12:19:32 -07:00
Allan Jude
b37d495e04
Avoid null pointer dereference in dsl_fs_ss_limit_check()
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
2022-10-29 13:08:54 -07:00
Richard Yao
97143b9d31 Introduce kmem_scnprintf()
`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
2022-10-29 13:05:11 -07:00
Richard Yao
d71d693261 Fix too few arguments to formatting function
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
2022-10-29 13:04:52 -07:00
Brian Behlendorf
82ad2a06ac
Revert "Cleanup: Delete dead code from send_merge_thread()"
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 #14042
Closes #14104
2022-10-28 13:25:37 -07:00
Mariusz Zaborski
8af08a69cd
quota: extend quota for dataset
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
2022-10-28 11:44:18 -07:00
shodanshok
dc56c673e3
Fix ARC target collapse when zfs_arc_meta_limit_percent=100
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 #14054 
Closes #14093
2022-10-28 10:21:54 -07:00
vaclavskala
7822b50f54
Propagate extent_bytes change to autotrim thread
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
2022-10-28 10:16:31 -07:00
Aleksa Sarai
dbf6108b4d zfs_rename: support RENAME_* flags
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 #12209
Closes #14070
2022-10-28 09:49:20 -07:00
Andrew Innes
e09fdda977
Fix multiplication converted to larger type
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
2022-10-28 09:30:37 -07:00
Richard Yao
4938d01db7
Convert enum zio_flag to uint64_t
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
2022-10-27 09:54:54 -07:00
Alexander Motin
9dcdee7889
Optimize microzaps
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
2022-10-20 11:57:15 -07:00
Richard Yao
411d327c67 Add defensive assertion to vdev_queue_aggregate()
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
2022-10-19 17:11:06 -07:00
Richard Yao
d692e6c36e abd_return_buf() should call zfs_refcount_remove_many() early
Calling zfs_refcount_remove_many() after freeing memory means we pass a
reference to freed memory as the holder. This is not believed to be able
to cause a problem, but there is a bit of a tradition of fixing these
issues when they appear so that they do not obscure more serious issues
in static analyzer output, so we fix this one too.

Clang's static analyzer found this with the help of CodeChecker's CTU
analysis.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14043
2022-10-19 17:11:01 -07:00
Richard Yao
44f71818f8 Silence static analyzer warnings about spa_sync_props()
Both Coverity and Clang's static analyzer complain about reading an
uninitialized intval if the property is not passed as DATA_TYPE_UINT64
in the nvlist. This is impossible becuase spa_prop_validate() already
checked this, but they are unlikely to be the last static analyzers to
complain about this, so lets just refactor the code to suppress the
warnings.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14043
2022-10-19 17:10:52 -07:00
Akash B
5405be0365
Add options to zfs redundant_metadata property
Currently, additional/extra copies are created for metadata in
addition to the redundancy provided by the pool(mirror/raidz/draid),
due to this 2 times more space is utilized per inode and this decreases
the total number of inodes that can be created in the filesystem. By
setting redundant_metadata to none, no additional copies of metadata
are created, hence can reduce the space consumed by the additional
metadata copies and increase the total number of inodes that can be
created in the filesystem.  Additionally, this can improve file create
performance due to the reduced amount of metadata which needs
to be written.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Signed-off-by: Akash B <akash-b@hpe.com>
Closes #13680
2022-10-19 17:07:51 -07:00
samwyc
2be0a124af
Fix sequential resilver drive failure race condition
This patch handles the race condition on simultaneous failure of
2 drives, which misses the vdev_rebuild_reset_wanted signal in
vdev_rebuild_thread. We retry to catch this inside the
vdev_rebuild_complete_sync function.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Samuel Wycliffe J <samwyc@hpe.com>
Closes #14041
Closes #14050
2022-10-19 15:48:13 -07:00
youzhongyang
2a068a1394
Support idmapped mount
Adds support for idmapped mounts.  Supported as of Linux 5.12 this 
functionality allows user and group IDs to be remapped without changing 
their state on disk.  This can be useful for portable home directories
and a variety of container related use cases.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #12923
Closes #13671
2022-10-19 11:17:09 -07:00
Richard Yao
eaaed26ffb
Fix memory leaks in dmu_send()/dmu_send_obj()
If we encounter an EXDEV error when using the redacted snapshots
feature, the memory used by dspp.fromredactsnaps is leaked.

Clang's static analyzer caught this during an experiment in which I had
annotated various headers in an attempt to improve the results of static
analysis.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13973
2022-10-18 16:03:33 -07:00
Richard Yao
84243acb91 Cleanup: Remove NULL pointer check from dmu_send_impl()
The pointer is to a structure member, so it is never NULL.

Coverity complained about this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14042
2022-10-18 15:40:04 -07:00
Richard Yao
fb823de9fb Cleanup: Delete dead code from send_merge_thread()
range is always deferenced before it reaches this check, such that the
kmem_zalloc() call is never executed.

There is also no need to set `range->eos_marker = B_TRUE` because it is
already set.

Coverity incorrectly complained about a potential NULL pointer
dereference because of this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14042
2022-10-18 15:39:56 -07:00
Richard Yao
717641ac09 Cleanup: zvol_add_clones() should not NULL check dp
It is never NULL because we return early if dsl_pool_hold() fails.

This caused Coverity to complain.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14042
2022-10-18 15:39:48 -07:00
Richard Yao
ef55679a75 Cleanup: metaslab_alloc_dva() should not NULL check mg->mg_next
This is a circularly linked list. mg->mg_next can never be NULL.

This caused 3 defect reports in Coverity.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14042
2022-10-18 15:39:40 -07:00
Richard Yao
1bd02680c0 Fix NULL pointer dereference in spa_open_common()
Calling spa_open() will pass a NULL pointer to spa_open_common()'s
config parameter. Under the right circumstances, we will dereference the
config parameter without doing a NULL check.

Clang's static analyzer found this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14044
2022-10-18 15:34:54 -07:00
Richard Yao
3146fc7edf Fix NULL pointer passed to strlcpy from zap_lookup_impl()
Clang's static analyzer pointed out that whenever zap_lookup_by_dnode()
is called, we have the following stack where strlcpy() is passed a NULL
pointer for realname from zap_lookup_by_dnode():

strlcpy()
zap_lookup_impl()
zap_lookup_norm_by_dnode()
zap_lookup_by_dnode()

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14044
2022-10-18 15:34:44 -07:00
Richard Yao
711b35dc24 fm_fmri_hc_create() must call va_end() before returning
clang-tidy caught this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14044
2022-10-18 15:34:36 -07:00
Tino Reichardt
27218a32fc
Fix declarations of non-global variables
This patch inserts the `static` keyword to non-global variables,
which where found by the analysis tool smatch.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #13970
2022-10-18 11:05:32 -07:00
Richard Yao
6a42939fcd
Cleanup: Address Clang's static analyzer's unused code complaints
These were categorized as the following:

 * Dead assignment		23
 * Dead increment		4
 * Dead initialization		6
 * Dead nested assignment	18

Most of these are harmless, but since actual issues can hide among them,
we correct them.

That said, there were a few return values that were being ignored that
appeared to merit some correction:

 * `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from
   `destroy_batched()`. We handle it by returning -1 if there is an
   error.

 * `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from
   `zfs_for_each()`. We handle it by doing a binary OR of the error
   value from the subsequent `zfs_for_each()` call to the existing
   value. This is how errors are mostly handled inside `zfs_for_each()`.
   The error value here is passed to exit from the zfs command, so doing
   a binary or on it is better than what we did previously.

 * `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from
   `dsl_prop_get_ds()` when the property is not of type string. We
   return an error when it does. There is a small concern that the
   `zfs_get_temporary_prop()` call would handle things, but in the case
   that it does not, we would be pushing an uninitialized numval onto
   the lua stack. It is expected that `dsl_prop_get_ds()` will succeed
   anytime that `zfs_get_temporary_prop()` does, so that not giving it a
   chance to fix things is not a problem.

 * `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used
   `nvlist_add_nvlist()` twice in ways in which errors are expected to
   be impossible, so we switch to `fnvlist_add_nvlist()`.

A few notable ones did not merit use of the return value, so we
suppressed it with `(void)`:

 * `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error
   value from `describe_free()`. A look through the commit history
   revealed that this was intentional.

 * `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the
   returned handle from `arc_hdr_realloc()` because it is already
   referenced in lists.

 * `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly
   saying not to use the error from `vdev_label_init()` because whatever
   causes the error could be the reason why a detach is being done.

Unfortunately, I am not presently able to analyze the kernel modules
with Clang's static analyzer, so I could have missed some cases of this.
In cases where reports were present in code that is duplicated between
Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version
too.

After this commit is merged, regressions like dee8934 should become
extremely obvious with Clang's static analyzer since a regression would
appear in the results as the only instance of unused code. That assumes
that Coverity does not catch the issue first.

My local branch with fixes from all of my outstanding non-draft pull
requests shows 118 reports from Clang's static anlayzer after this
patch. That is down by 51 from 169.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13986
2022-10-14 13:37:54 -07:00
Richard Yao
ab8d9c1783 Cleanup: 64-bit kernel module parameters should use fixed width types
Various module parameters such as `zfs_arc_max` were originally
`uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long`
for Linux compatibility because Linux's kernel default module parameter
implementation did not support 64-bit types on 32-bit platforms. This
caused problems when porting OpenZFS to Windows because its LLP64 memory
model made `unsigned long` a 32-bit type on 64-bit, which created the
undesireable situation that parameters that should accept 64-bit values
could not on 64-bit Windows.

Upon inspection, it turns out that the Linux kernel module parameter
interface is extensible, such that we are allowed to define our own
types. Rather than maintaining the original type change via hacks to to
continue shrinking module parameters on 32-bit Linux, we implement
support for 64-bit module parameters on Linux.

After doing a review of all 64-bit kernel parameters (found via the man
page and also proposed changes by Andrew Innes), the kernel module
parameters fell into a few groups:

Parameters that were originally 64-bit on Illumos:

 * dbuf_cache_max_bytes
 * dbuf_metadata_cache_max_bytes
 * l2arc_feed_min_ms
 * l2arc_feed_secs
 * l2arc_headroom
 * l2arc_headroom_boost
 * l2arc_write_boost
 * l2arc_write_max
 * metaslab_aliquot
 * metaslab_force_ganging
 * zfetch_array_rd_sz
 * zfs_arc_max
 * zfs_arc_meta_limit
 * zfs_arc_meta_min
 * zfs_arc_min
 * zfs_async_block_max_blocks
 * zfs_condense_max_obsolete_bytes
 * zfs_condense_min_mapping_bytes
 * zfs_deadman_checktime_ms
 * zfs_deadman_synctime_ms
 * zfs_initialize_chunk_size
 * zfs_initialize_value
 * zfs_lua_max_instrlimit
 * zfs_lua_max_memlimit
 * zil_slog_bulk

Parameters that were originally 32-bit on Illumos:

 * zfs_per_txg_dirty_frees_percent

Parameters that were originally `ssize_t` on Illumos:

 * zfs_immediate_write_sz

Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It
has been upgraded to 64-bit.

Parameters that were `long`/`unsigned long` because of Linux/FreeBSD
influence:

 * l2arc_rebuild_blocks_min_l2size
 * zfs_key_max_salt_uses
 * zfs_max_log_walking
 * zfs_max_logsm_summary_length
 * zfs_metaslab_max_size_cache_sec
 * zfs_min_metaslabs_to_flush
 * zfs_multihost_interval
 * zfs_unflushed_log_block_max
 * zfs_unflushed_log_block_min
 * zfs_unflushed_log_block_pct
 * zfs_unflushed_max_mem_amt
 * zfs_unflushed_max_mem_ppm

New parameters that do not exist in Illumos:

 * l2arc_trim_ahead
 * vdev_file_logical_ashift
 * vdev_file_physical_ashift
 * zfs_arc_dnode_limit
 * zfs_arc_dnode_limit_percent
 * zfs_arc_dnode_reduce_percent
 * zfs_arc_meta_limit_percent
 * zfs_arc_sys_free
 * zfs_deadman_ziotime_ms
 * zfs_delete_blocks
 * zfs_history_output_max
 * zfs_livelist_max_entries
 * zfs_max_async_dedup_frees
 * zfs_max_nvlist_src_size
 * zfs_rebuild_max_segment
 * zfs_rebuild_vdev_limit
 * zfs_unflushed_log_txg_max
 * zfs_vdev_max_auto_ashift
 * zfs_vdev_min_auto_ashift
 * zfs_vnops_read_chunk_size
 * zvol_max_discard_blocks

Rather than clutter the lists with commentary, the module parameters
that need comments are repeated below.

A few parameters were defined in Linux/FreeBSD specific code, where the
use of ulong/long is not an issue for portability, so we leave them
alone:

 * zfs_delete_blocks
 * zfs_key_max_salt_uses
 * zvol_max_discard_blocks

The documentation for a few parameters was found to be incorrect:

 * zfs_deadman_checktime_ms - incorrectly documented as int
 * zfs_delete_blocks - not documented as Linux only
 * zfs_history_output_max - incorrectly documented as int
 * zfs_vnops_read_chunk_size - incorrectly documented as long
 * zvol_max_discard_blocks - incorrectly documented as ulong

The documentation for these has been fixed, alongside the changes to
document the switch to fixed width types.

In addition, several kernel module parameters were percentages or held
ashift values, so being 64-bit never made sense for them. They have been
downgraded to 32-bit:

 * vdev_file_logical_ashift
 * vdev_file_physical_ashift
 * zfs_arc_dnode_limit_percent
 * zfs_arc_dnode_reduce_percent
 * zfs_arc_meta_limit_percent
 * zfs_per_txg_dirty_frees_percent
 * zfs_unflushed_log_block_pct
 * zfs_vdev_max_auto_ashift
 * zfs_vdev_min_auto_ashift

Of special note are `zfs_vdev_max_auto_ashift` and
`zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`,
and passed to the kernel as `ulong`. This is inherently buggy on big
endian 32-bit Linux, since the values would not be written to the
correct locations. 32-bit FreeBSD was unaffected because its sysctl code
correctly treated this as a `uint64_t`.

Lastly, a code comment suggests that `zfs_arc_sys_free` is
Linux-specific, but there is nothing to indicate to me that it is
Linux-specific. Nothing was done about that.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Original-patch-by: Andrew Innes <andrew.c12@gmail.com>
Original-patch-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13984
Closes #14004
2022-10-13 10:03:29 -07:00
Richard Yao
a6ccb36b94
Add defensive assertions
Coverity complains about possible bugs involving referencing NULL return
values and division by zero. The division by zero bugs require that a
block pointer be corrupt, either from in-memory corruption, or on-disk
corruption. The NULL return value complaints are only bugs if
assumptions that we make about the state of data structures are wrong.
Some seem impossible to be wrong and thus are false positives, while
others are hard to analyze.

Rather than dismiss these as false positives by assuming we know better,
we add defensive assertions to let us know when our assumptions are
wrong.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13972
2022-10-12 11:25:18 -07:00
Serapheim Dimitropoulos
4dcc2bde9c
Stop ganging due to past vdev write errors
= Problem

While examining a customer's system we noticed unreasonable space
usage from a few snapshots due to gang blocks. Under some further
analysis we discovered that the pool would create gang blocks because
all its disks had non-zero write error counts and they'd be skipped
for normal metaslab allocations due to the following if-clause in
`metaslab_alloc_dva()`:
```
	/*
	 * Avoid writing single-copy data to a failing,
	 * non-redundant vdev, unless we've already tried all
	 * other vdevs.
	 */
	if ((vd->vdev_stat.vs_write_errors > 0 ||
	    vd->vdev_state < VDEV_STATE_HEALTHY) &&
	    d == 0 && !try_hard && vd->vdev_children == 0) {
		metaslab_trace_add(zal, mg, NULL, psize, d,
		    TRACE_VDEV_ERROR, allocator);
		goto next;
	}
```

= Proposed Solution

Get rid of the predicate in the if-clause that checks the past
write errors of the selected vdev. We still try to allocate from
HEALTHY vdevs anyway by checking vdev_state so the past write
errors doesn't seem to help us (quite the opposite - it can cause
issues in long-lived pools like the one from our customer).

= Testing

I first created a pool with 3 vdevs:
```
$ zpool list -v volpool
NAME        SIZE  ALLOC   FREE
volpool    22.5G   117M  22.4G
  xvdb     7.99G  40.2M  7.46G
  xvdc     7.99G  39.1M  7.46G
  xvdd     7.99G  37.8M  7.46G
```

And used `zinject` like so with each one of them:
```
$ sudo zinject -d xvdb -e io -T write -f 0.1 volpool
```

And got the vdevs to the following state:
```
$ zpool status volpool
  pool: volpool
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.
...<cropped>..
action: Determine if the device needs to be replaced, and clear the
...<cropped>..
config:

	NAME        STATE     READ WRITE CKSUM
	volpool     ONLINE       0     0     0
	  xvdb      ONLINE       0     1     0
	  xvdc      ONLINE       0     1     0
	  xvdd      ONLINE       0     4     0

```

I also double-checked their write error counters with sdb:
```
sdb> spa volpool | vdev | member vdev_stat.vs_write_errors
(uint64_t)0  # <---- this is the root vdev
(uint64_t)2
(uint64_t)1
(uint64_t)1
```

Then I checked that I the problem was reproduced in my VM as I the
gang count was growing in zdb as I was writting more data:
```
$ sudo zdb volpool | grep gang
        ganged count:              1384

$ sudo zdb volpool | grep gang
        ganged count:              1393

$ sudo zdb volpool | grep gang
        ganged count:              1402

$ sudo zdb volpool | grep gang
        ganged count:              1414
```

Then I updated my bits with this patch and the gang count stayed the
same.

Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #14003
2022-10-11 12:27:41 -07:00
Richard Yao
70248b82e8
Fix uninitialized value read in vdev_prop_set()
If no errors are encountered, we read an uninitialized error value.

Clang's static analyzer complained about this.

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14007
2022-10-11 12:24:36 -07:00
Finix1979
6694ca5539
Avoid unnecessary metaslab_check_free calling
The metaslab_check_free() function only needs to be called in the
GANG|DEDUP|etc case because zio_free_sync() will internally call
metaslab_check_free().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Finix1979 <yancw@info2soft.com>
Closes #13977
2022-10-04 10:55:35 -07:00
Richard Yao
a36b37d4de
Fix potential NULL pointer dereference in dsl_dataset_promote_check()
If the `list_head()` returns NULL, we dereference it, right before we
check to see if it returned NULL.

We have defined two different pointers that both point to the same
thing, which are `origin_head` and `origin_ds`. Almost everything uses
`origin_ds`, so we switch them to use `origin_ds`.

We also promote `origin_ds` to a const pointer so that the compiler
verifies that nothing modifies it.

Coverity complained about this.

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 #13967
2022-09-30 16:59:51 -07:00
Tino Reichardt
a2d5643f88
Fix double const qualifier declarations
Some header files define structures like this one:

typedef const struct zio_checksum_info {
	/* ... */
	const char	*ci_name;
} zio_abd_checksum_func_t;

So we can use `zio_abd_checksum_func_t` for const declarations now.
It's not needed that we use the `const` qualifier again like this:
`const zio_abd_checksum_func_t *varname;`

This patch solves the double const qualifiers, which were found by
smatch.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #13961
2022-09-30 15:34:39 -07:00
Serapheim Dimitropoulos
4acc36ed7c
Fix panic in dsl_process_sub_livelist for EINTR
= Issue

Recently we hit an assertion panic in `dsl_process_sub_livelist` while
exporting the spa and interrupting `bpobj_iterate_nofree`. In that case
`bpobj_iterate_nofree` stops mid-way returning an EINTR without clearing
the intermediate AVL tree that keeps track of the livelist entries it
has encountered so far. At that point the code has a VERIFY for the
number of elements of the AVL expecting it to be zero (which is not the
case for EINTR).

= Fix

Cleanup any intermediate state before destroying the AVL when
encountering EINTR. Also added a comment documenting the scenario where
the EINTR comes up. There is no need to do anything else for the calles
of `dsl_process_sub_livelist` as they already handle the EINTR case.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #13939
2022-09-29 09:39:48 -07:00
Richard Yao
1b87195c3c
Fix unchecked return values
2a493a4c71 was intended to fix all
instances of coverity reported unchecked return values, but
unfortunately, two were missed by mistake. This commit fixes the
unchecked return values that had been missed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13945
2022-09-29 09:02:57 -07:00
Ameer Hamza
55c12724d3
zed: mark disks as REMOVED when they are removed
ZED does not take any action for disk removal events if there is no
spare VDEV available. Added zpool_vdev_remove_wanted() in libzfs
and vdev_remove_wanted() in vdev.c to remove the VDEV through ZED
on removal event.  This means that if you are running zed and
remove a disk, it will be properly marked as REMOVED.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #13797
2022-09-28 09:48:46 -07:00
Mateusz Guzik
eb9bec0a5d
Bring per_txg_dirty_frees_percent back to 30
The current value causes significant artificial slowdown during mass
parallel file removal, which can be observed both on FreeBSD and Linux
when running real workloads.

Sample results from Linux doing make -j 96 clean after an allyesconfig
modules build:

before: 4.14s user 6.79s system 48% cpu 22.631 total
after:	4.17s user 6.44s system 153% cpu 6.927 total

FreeBSD results in the ticket.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by:	Mateusz Guzik <mjguzik@gmail.com>
Closes #13932
Closes #13938
2022-09-27 17:38:03 -07:00
Richard Yao
a51288aabb
Fix unsafe string operations
Coverity caught unsafe use of `strcpy()` in `ztest_dmu_objset_own()`,
`nfs_init_tmpfile()` and `dump_snapshot()`. It also caught an unsafe use
of `strlcat()` in `nfs_init_tmpfile()`.

Inspired by this, I did an audit of every single usage of `strcpy()` and
`strcat()` in the code. If I could not prove that the usage was safe, I
changed the code to use either `strlcpy()` or `strlcat()`, depending on
which function was originally used. In some cases, `snprintf()` was used
to replace multiple uses of `strcat` because it was cleaner.

Whenever I changed a function, I preferred to use `sizeof(dst)` when the
compiler is able to provide the string size via that. When it could not
because the string was passed by a caller, I checked the entire call
tree of the function to find out how big the buffer was and hard coded
it. Hardcoding is less than ideal, but it is safe unless someone shrinks
the buffer sizes being passed.

Additionally, Coverity reported three more string related issues:

 * It caught a case where we do an overlapping memory copy in a call to
   `snprintf()`. We fix that via `kmem_strdup()` and `kmem_strfree()`.

 * It caught `sizeof (buf)` being used instead of `buflen` in
   `zdb_nicenum()`'s call to `zfs_nicenum()`, which is passed to
   `snprintf()`. We change that to pass `buflen`.

 * It caught a theoretical unterminated string passed to `strcmp()`.
   This one is likely a false positive, but we have the information
   needed to do this more safely, so we change this to silence the false
   positive not just in coverity, but potentially other static analysis
   tools too. We switch to `strncmp()`.

 * There was a false positive in tests/zfs-tests/cmd/dir_rd_update.c. We
   suppress it by switching to `snprintf()` since other static analysis
   tools might complain about it too. Interestingly, there is a possible
   real bug there too, since it assumes that the passed directory path
   ends with '/'. We add a '/' to fix that potential bug.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13913
2022-09-27 16:47:24 -07:00
Richard Yao
88b199c24e
Cleanup spa_export_common()
Coverity complains about a possible NULL pointer dereference. This is
impossible, but it suspects it because we do a NULL check against
`spa->spa_root_vdev`. This NULL check was never necessary and makes the
code harder to understand, so we drop it.

In particular, we dereference `spa->spa_root_vdev` when `new_state !=
POOL_STATE_UNINITIALIZED && !hardforce`. The first is only true when
spa_reset is called, which only occurs under fault injection.  The
second is true unless `zpool export -F $POOLNAME` is used.  Therefore,
we effectively *always* dereference the pointer. In the cases where we
do not, there is no reason to think it is unsafe.  Therefore this change
is safe to make.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13905
2022-09-27 16:45:51 -07:00
Richard Yao
fdc2d30371
Cleanup: Specify unsignedness on things that should not be signed
In #13871, zfs_vdev_aggregation_limit_non_rotating and
zfs_vdev_aggregation_limit being signed was pointed out as a possible
reason not to eliminate an unnecessary MAX(unsigned, 0) since the
unsigned value was assigned from them.

There is no reason for these module parameters to be signed and upon
inspection, it was found that there are a number of other module
parameters that are signed, but should not be, so we make them unsigned.
Making them unsigned made it clear that some other variables in the code
should also be unsigned, so we also make those unsigned. This prevents
users from setting negative values that could potentially cause bad
behaviors. It also makes the code slightly easier to understand.

Mostly module parameters that deal with timeouts, limits, bitshifts and
percentages are made unsigned by this. Any that are boolean are left
signed, since whether booleans should be considered signed or unsigned
does not matter.

Making zfs_arc_lotsfree_percent unsigned caused a
`zfs_arc_lotsfree_percent >= 0` check to become redundant, so it was
removed. Removing the check was also necessary to prevent a compiler
error from -Werror=type-limits.

Several end of line comments had to be moved to their own lines because
replacing int with uint_t caused us to exceed the 80 character limit
enforced by cstyle.pl.

The following were kept signed because they are passed to
taskq_create(), which expects signed values and modifying the
OpenSolaris/Illumos DDI is out of scope of this patch:

	* metaslab_load_pct
	* zfs_sync_taskq_batch_pct
	* zfs_zil_clean_taskq_nthr_pct
	* zfs_zil_clean_taskq_minalloc
	* zfs_zil_clean_taskq_maxalloc
	* zfs_arc_prune_task_threads

Also, negative values in those parameters was found to be harmless.

The following were left signed because either negative values make
sense, or more analysis was needed to determine whether negative values
should be disallowed:

	* zfs_metaslab_switch_threshold
	* zfs_pd_bytes_max
	* zfs_livelist_min_percent_shared

zfs_multihost_history was made static to be consistent with other
parameters.

A number of module parameters were marked as signed, but in reality
referenced unsigned variables. upgrade_errlog_limit is one of the
numerous examples. In the case of zfs_vdev_async_read_max_active, it was
already uint32_t, but zdb had an extern int declaration for it.

Interestingly, the documentation in zfs.4 was right for
upgrade_errlog_limit despite the module parameter being wrongly marked,
while the documentation for zfs_vdev_async_read_max_active (and friends)
was wrong. It was also wrong for zstd_abort_size, which was unsigned,
but was documented as signed.

Also, the documentation in zfs.4 incorrectly described the following
parameters as ulong when they were int:

	* zfs_arc_meta_adjust_restarts
	* zfs_override_estimate_recordsize

They are now uint_t as of this patch and thus the man page has been
updated to describe them as uint.

dbuf_state_index was left alone since it does nothing and perhaps should
be removed in another patch.

If any module parameters were missed, they were not found by `grep -r
'ZFS_MODULE_PARAM' | grep ', INT'`. I did find a few that grep missed,
but only because they were in files that had hits.

This patch intentionally did not attempt to address whether some of
these module parameters should be elevated to 64-bit parameters, because
the length of a long on 32-bit is 32-bit.

Lastly, it was pointed out during review that uint_t is a better match
for these variables than uint32_t because FreeBSD kernel parameter
definitions are designed for uint_t, whose bit width can change in
future memory models.  As a result, we change the existing parameters
that are uint32_t to use uint_t.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
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 #13875
2022-09-27 16:42:41 -07:00
Richard Yao
7584fbe846
Cleanup: Switch to strlcpy from strncpy
Coverity found a bug in `zfs_secpolicy_create_clone()` where it is
possible for us to pass an unterminated string when `zfs_get_parent()`
returns an error. Upon inspection, it is clear that using `strlcpy()`
would have avoided this issue.

Looking at the codebase, there are a number of other uses of `strncpy()`
that are unsafe and even when it is used safely, switching to
`strlcpy()` would make the code more readable. Therefore, we switch all
instances where we use `strncpy()` to use `strlcpy()`.

Unfortunately, we do not portably have access to `strlcpy()` in
tests/zfs-tests/cmd/zfs_diff-socket.c because it does not link to
libspl. Modifying the appropriate Makefile.am to try to link to it
resulted in an error from the naming choice used in the file. Trying to
disable the check on the file did not work on FreeBSD because Clang
ignores `#undef` when a definition is provided by `-Dstrncpy(...)=...`.
We workaround that by explictly including the C file from libspl into
the test. This makes things build correctly everywhere.

We add a deprecation warning to `config/Rules.am` and suppress it on the
remaining `strncpy()` usage. `strlcpy()` is not portably avaliable in
tests/zfs-tests/cmd/zfs_diff-socket.c, so we use `snprintf()` there as a
substitute.

This patch does not tackle the related problem of `strcpy()`, which is
even less safe. Thankfully, a quick inspection found that it is used far
more correctly than strncpy() was used. A quick inspection did not find
any problems with `strcpy()` usage outside of zhack, but it should be
said that I only checked around 90% of them.

Lastly, some of the fields in kstat_t varied in size by 1 depending on
whether they were in userspace or in the kernel. The origin of this
discrepancy appears to be 04a479f706 where
it was made for no apparent reason. It conflicts with the comment on
KSTAT_STRLEN, so we shrink the kernel field sizes to match the userspace
field sizes.

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 #13876
2022-09-27 16:35:29 -07:00
Jitendra Patidar
3ed9d6883b
Enforce "-F" flag on resuming recv of full/newfs on existing dataset
When receiving full/newfs on existing dataset, then it should be done
with "-F" flag. Its enforced for initial receive in checks done in
zfs_receive_one function of libzfs. Similarly, on resuming full/newfs
recv on existing dataset, it should be done with "-F" flag.

When dataset doesn't exist, then full/new recv is done on newly created
dataset and it's marked INCONSISTENT. But when receiving on existing
dataset, recv is first done on %recv and its marked INCONSISTENT.
Existing dataset is not marked INCONSISTENT. Resume of full/newfs
receive with dataset not INCONSISTENT indicates that its resuming newfs
on existing dataset. So, enforce "-F" flag in this case.

Also return an error from dmu_recv_resume_begin_check() in zfs kernel,
when its resuming full/newfs recv without force.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@nutanix.com>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes #13856
Closes #13857
2022-09-27 16:34:27 -07:00
Richard Yao
f7bda2de97
Fix userspace memory leaks found by Clang Static Analzyer
Recently, I have been making a push to fix things that coverity found.
However, I was curious what Clang's static analyzer reported, so I ran
it and found things that coverity had missed.

* contrib/pam_zfs_key/pam_zfs_key.c: If prop_mountpoint is passed more
  than once, we leak memory.
* module/zfs/zcp_get.c: We leak memory on temporary properties in
  userspace.
* tests/zfs-tests/cmd/draid.c: On error from vdev_draid_rand(), we leak
  memory if best_map had been allocated by a prior iteration.
* tests/zfs-tests/cmd/mkfile.c: Memory used by the loop is not freed
  before program termination.

Arguably, these are all minor issues, but if we ignore them, then they
could obscure serious bugs, so we fix them.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13955
2022-09-26 17:18:05 -07:00
Richard Yao
8ef15f9322
Cleanup: Remove ineffective unsigned comparisons against 0
Coverity found a number of places where we either do MAX(unsigned, 0) or
do assertions that a unsigned variable is >= 0. These do nothing, so
let us drop them all.

It also found a spot where we do `if (unsigned >= 0 && ...)`. Let us
also drop the unsigned >= 0 check.

Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13871
2022-09-26 17:02:38 -07:00
Richard Yao
2a493a4c71
Fix unchecked return values and unused return values
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.

Different approaches were used to handle the different cases of
unchecked return values:

* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
  had no error handling. An error message was printed in another to
  match the rest of the code.

* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
  because the value is expected to be potentially unset.

* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
  `(void)` because the values are expected to be potentially unset.

* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
  wrong in ztest.

* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
  because there is no guarantee that the zap entry will always be there.
  For example, old pools imported readonly would not have it and we do
  not want to fail here because of that.

* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
  allocations sleep and thus can never fail.

* module/zfs/zvol.c: We dismiss the return value with `(void)` because
  we do not need it. This matches what is already done in the analogous
  `zfs_replay_write2()`.

* tests/zfs-tests/cmd/draid.c: We suppress one return value with
  `(void)` since the code handles errors already. The other return value
  is handled by switching to `fnvlist_lookup_uint8_array()`.

* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.

* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
  ignore failures on remove() with (void) since it is expected to be
  able to fail.

* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.

As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13920
2022-09-23 16:52:03 -07:00
Brian Behlendorf
505df8d133 Dynamically size dbuf hash mutex array
Incorrectly sizing the array of hash locks used to protect the
dbuf hash table can lead to contention and reduce performance.
We could unconditionally allocate a larger array for the locks
but it's wasteful, particularly for a low-memory system.
Instead, dynamically allocate the array of locks and scale
it based on total system memory.

Additionally, add a new `dbuf_mutex_cache_shift` module option
which can be used to override the hash lock array size.  This is
disabled by default (dbuf_mutex_hash_shift=0) and can only be
set at module load time.  The minimum target array size is set
to 8192, this matches the current constant value.

Note that the count of the dbuf hash table and count of the
mutex array were added to the /proc/spl/kstat/zfs/dbufstats
kstat.

Finally, this change removes the _KERNEL conditional checks.
These were not required since for the user space build there
is no difference between the kmem and vmem interfaces.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13928
2022-09-22 12:59:56 -07:00
Brian Behlendorf
223b04d23d Revert "Reduce dbuf_find() lock contention"
This reverts commit 34dbc618f5.  While this
change resolved the lock contention observed for certain workloads, it
inadventantly reduced the maximum hash inserts/removes per second.  This
appears to be due to the slightly higher acquisition cost of a rwlock vs
a mutex.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
2022-09-22 12:59:41 -07:00
Richard Yao
e506a0ce40
Cleanup: Change 1 used in bitshifts to 1ULL
Coverity complains about this. It is not a bug as long as we never shift
by more than 31, but it is not terrible to change the constants from 1
to 1ULL as clean up.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13914
2022-09-22 11:28:33 -07:00