Linux 5.16 moved these functions into this new header in commit
1b4fb8545f2b00f2844c4b7619d64d98440a477c. This change adds code to look
for the presence of this header, and include it so that the code using
xgetbv & xsetbv will compile again.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12800
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12049
The upload artifact functionality in github can't handle colons in
filenames. The current code handles this for files under the most
recent set of results. With the ability to rerun failed tests, now
there can be multiple sets of results, and they all need to be
processed in the same way.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: John Kennedy <john.kennedy@delphix.com>
Closes#12815
Due to a possible lock inversion the zvol open call path on Linux
needs to be able to retry in the case where the spa_namespace_lock
cannot be acquired.
For Linux 5.12 an older kernel this was accomplished by returning
-ERESTARTSYS from zvol_open() to request that blkdev_get() drop
the bdev->bd_mutex lock, reaquire it, then call the open callback
again. However, as of the 5.13 kernel this behavior was removed.
Therefore, for 5.12 and older kernels we preserved the existing
retry logic, but for 5.13 and newer kernels we retry internally in
zvol_open(). This should always succeed except in the case where
a pool's vdev are layed on zvols, in which case it may fail. To
handle this case vdev_disk_open() has been updated to retry when
opening a device when -ERESTARTSYS is returned.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #12301Closes#12759
With the addition of functionality to rerun failing tests, some
tests that fail only sometimes still fail often enough to degrade
the reliability of the sanity runs. Remove them from the runfile
until they reliably pass.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: John Kennedy <john.kennedy@delphix.com>
Closes#12814
This was a project proposed as part of the Quality theme for the
hackthon for the 2021 OpenZFS Developer Summit. The idea is to improve
the usability of the automated tests that get run when a PR is created
by having failing tests automatically rerun in order to make flaky
tests less impactful.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#12740
Instead, linux/pagemap.h offers a number of folio-specific functions to
be called instead. In this case, module/os/linux/zfs/zfs_vnops_os.c
wants to call wait_on_page_bit(pp, PG_writeback). This gets replaced
with folio_wait_bit(folio_page(pp), PG_writeback). This change modifies
the code to conditionally compile that if configure identifies th
presence of the folio_wait_bit() function.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12800
Userland figures out which encryption-root keys are required to load,
and issues ZFS_IOC_LOAD_KEY.
The tail section of spa_keystore_load_wkey() will call
zvol_create_minors() on the encryption-root object.
Any clones of the encrypted zvol will not be plumbed. This commits
adds additional logic to detect if zvol has clones, and is encrypted,
then adds these to the list of zvols to call zvol_create_minors() on.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#12471
In the course of cherry-picking commits, the ABI files from master
and the code in zfs-2.0.7 can get out of sync, and the ABIs need
to be regenerated. This patch just runs 'make storeabi' on the
previous commit and checks in the new ABI files.
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
It's present (but undocumented) in the illumos gate and used exclusively
by rmformat(1) (which I recommend as a nice blast from the past),
and also the math assumes 512B sectors and is therefore wrong
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12191
The double free reported for the realloc() failure branch is a
false positive. It should be resolved in cppcheck 2.4 but for
the benefit of older versions we supress the warning.
https://trac.cppcheck.net/ticket/9292
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11508
In addition to flushing memory mapped regions when checking holes,
commit de198f2d95 modified the dirty dnode detection logic to check
the dn->dn_dirty_records instead of the dn->dn_dirty_link. Relying
on the dirty record has not be reliable, switch back to the previous
method.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #11900Closes#12745
When using lseek(2) to report data/holes memory mapped regions of
the file were ignored. This could result in incorrect results.
To handle this zfs_holey_common() was updated to asynchronously
writeback any dirty mmap(2) regions prior to reporting holes.
Additionally, while not strictly required, the dn_struct_rwlock is
now held over the dirty check to prevent the dnode structure from
changing. This ensures that a clean dnode can't be dirtied before
the data/hole is located. The range lock is now also taken to
ensure the call cannot race with zfs_write().
Furthermore, the code was refactored to provide a dnode_is_dirty()
helper function which checks the dnode for any dirty records to
determine its dirtiness.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #11900Closes#12724
The ZED code currently can only turn on the fault LED for
a faulted disk in a JBOD enclosure. This extends support
for faulted NVMe disks as well.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#12648Closes#12695
The submit_bio() prototype has changed again. The version is 5.16
still only expects a single argument but the return type has changed
to void. Since we never used the returned value before update the
configure check to detect both single arg versions.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12725
Commit https://github.com/torvalds/linux/commit/2e9bc346 moved
the elevator.h header under the block/ directory as part of some
refactoring. This turns out not to be a problem since there's
no longer anything we need from the header. This has been the
case for some time, this change removes the elevator.h include
and replaces it with a major.h include.
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12725
Also minor clean-up with folding state_to_val() into a case,
unrolling the lesser-available seq into numbers,
ignoring vdev states we don't care about,
and documentation comments
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11934Closes#11935
It turns out that short-circuiting the EFAULT behavior on a short read
breaks things on FreeBSD. So until there's a nicer solution, let's
just revert the behavior for not-Linux.
Reference:
https://reviews.freebsd.org/R10:70f51f0e474ffe1fb74cb427423a2fba3637544d
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12698
Currently, dmu_read_uio_dnode can read 64K of a requested 1M in one
loop, get EFAULT back from zfs_uiomove() (because the iovec only holds
64k), and return EFAULT, which turns into EAGAIN on the way out. EAGAIN
gets interpreted as "I didn't read anything", the caller tries again
without consuming the 64k we already read, and we're stuck.
This apparently works on newer kernels because the caller which breaks
on older Linux kernels by happily passing along a 1M read request and a
64k iovec just requests 64k at a time.
With this, we now won't return EFAULT if we got a partial read.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12370Closes#12509Closes#12516
Making uio_impl.h the common header interface between Linux and FreeBSD
so both OS's can share a common header file. This also helps reduce code
duplication for zfs_uio_t for each OS.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11622
In FreeBSD the struct uio was just a typedef to uio_t. In order to
extend this struct, outside of the definition for the struct uio, the
struct uio has been embedded inside of a uio_t struct.
Also renamed all the uio_* interfaces to be zfs_uio_* to make it clear
this is a ZFS interface.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11438
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11176
The original xuio zero copy functionality has always been unused
on Linux and FreeBSD. Remove this disabled code to avoid any
confusion and improve readability.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#11124
One of our developers noticed a bug in vdev_id where we were incorrectly
sorting PHYs using alphabetical sorting (which usually works) instead
of natural sorting (-v). For example:
[port-0:0]# ls -d phy*
phy-0:10 phy-0:11 phy-0:8 phy-0:9
[port-0:0]# ls -vd phy*
phy-0:8 phy-0:9 phy-0:10 phy-0:11
This fixes the issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#12699
The vdev_id.conf "enclosure_symlinks" option persistently creates
and maps /dev/by-enclosure symlinks to dynamic /dev/sg* devices.
This patch fixes two issues:
1. The enclosure_symlinks feature was accidentally broken in:
vdev_id: Support daisy-chained JBODs in multipath mode
2. Even when working, the feature numbered the enclosure
sequentially rather than by HBA port number. That meant that
if a port was down or didn't appear in sysfs, then the
enclosure_sumlinks numbers would be numbered wrong.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#12660
When you create a pool, zfs writes vd->vdev_enc_sysfs_path with the
enclosure sysfs path to the fault LEDs, like:
vdev_enc_sysfs_path = /sys/class/enclosure/0:0:1:0/SLOT8
However, this enclosure path doesn't get updated on successive imports
even if enclosure path to the disk changes. This patch fixes the issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#11950Closes#12095
Signed-off-by: Anton Gubarkov <anton.gubarkov@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Also yeet pci_slot since it doesn't seem to exist?
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12125
Also always free tmp2 at the end
Before:
nabijaczleweli@tarta:~/uwu$ valgrind --leak-check=full ./blergh
==8947== Memcheck, a memory error detector
==8947== Using Valgrind-3.14.0 and LibVEX
==8947== Command: ./blergh
==8947==
(null)
==8947==
==8947== HEAP SUMMARY:
==8947== in use at exit: 23 bytes in 1 blocks
==8947== total heap usage: 3 allocs, 2 frees, 1,147 bytes allocated
==8947==
==8947== 23 bytes in 1 blocks are definitely lost in loss record 1 of 1
==8947== at 0x483577F: malloc (vg_replace_malloc.c:299)
==8947== by 0x48D74B7: vasprintf (vasprintf.c:73)
==8947== by 0x48B7833: asprintf (asprintf.c:35)
==8947== by 0x401258: zfs_get_enclosure_sysfs_path
(zutil_device_path_os.c:191)
==8947== by 0x401482: main (blergh.c:107)
==8947==
==8947== LEAK SUMMARY:
==8947== definitely lost: 23 bytes in 1 blocks
==8947== indirectly lost: 0 bytes in 0 blocks
==8947== possibly lost: 0 bytes in 0 blocks
==8947== still reachable: 0 bytes in 0 blocks
==8947== suppressed: 0 bytes in 0 blocks
==8947==
==8947== For counts of detected and suppressed errors, rerun with: -v
==8947== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
nabijaczleweli@tarta:~/uwu$ sed -n 191p zutil_device_path_os.c
tmpsize = asprintf(&tmp1, "/sys/block/%s/device", dev_name);
After:
nabijaczleweli@tarta:~/uwu$ valgrind --leak-check=full ./blergh
==9512== Memcheck, a memory error detector
==9512== Using Valgrind-3.14.0 and LibVEX
==9512== Command: ./blergh
==9512==
(null)
==9512==
==9512== HEAP SUMMARY:
==9512== in use at exit: 0 bytes in 0 blocks
==9512== total heap usage: 3 allocs, 3 frees, 1,147 bytes allocated
==9512==
==9512== All heap blocks were freed -- no leaks are possible
==9512==
==9512== For counts of detected and suppressed errors, rerun with: -v
==9512== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11993
Under function map_slot() variable passed as args
were not getting properly substituted or expanded.
This patch fixes the substitution issue.
Reviewed-by: Niklas Edmundsson <nikke@acc.umu.se>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Closes#11951Closes#11959
vdev_id uses the /dev/mapper/ symlinks to resolve a UUID to a dm name
(like dm-1). However on some multipath setups, there is no /dev/mapper/
entry for the UUID at the time vdev_id is called by udev. However,
this isn't necessarily needed, as we may be able to resolve the dm
name from the $DEVNAME that udev passes us (like DEVNAME="/dev/dm-1").
This patch tries to resolve the dm name from $DEVNAME first, before
falling back to looking in /dev/mapper/. This fixed an issue where the
by-vdev names weren't reliably showing up on one of our nodes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#11698
Given a DM device name, the old vdev_id script would extract any text
after a 'p' as the partition number. It then appends "-part" + the
partition number to the name, giving a by-vdev name like "L0-part5".
This works fine if the DM name is like 'dm-2p5', but doesn't work if
the DM name is a multipath name like "mpatha". In those cases it
incorrectly matches the 'p' in "mpatha", giving by-vdev names like
"L0-partatha".
This patch fixes the issue by making the partition regex match stricter.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#11637
A multpathed disk will have several 'underlying' paths to the disk. For
example, multipath disk 'dm-0' may be made up of paths:
/dev/{sda,sdb,sdc,sdd}. On many enclosures those underlying sysfs
paths will have a symlink back to their enclosure device entry
(like 'enclosure_device0/slot1'). This is used by the
statechange-led.sh script to set/clear the fault LED for a disk, and
by 'zpool status -c'.
However, on some enclosures, those underlying paths may not all have
symlinks back to the enclosure device. Maybe only two out of four
of them might.
This patch updates zfs_get_enclosure_sysfs_path() to favor returning
paths that have symlinks back to their enclosure devices, rather
than just returning the first path.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#11617
Within function sas_handler() userspace commands like
'/usr/sbin/multipath' have been replaced with sourcing
device details from within sysfs which reduced a
significant amount of overhead and processing time.
Multiple JBOD enclosures and their order are sourced
from the bsg driver (/sys/class/enclosure) to isolate
chassis top-level expanders, which are then dynamically
indexed based on host channel of the multipath subordinate
disk member device being processed. Additionally added a
"mixed" mode for slot identification for environments where
a ZFS server system may contain SAS disk slots where there
is no expander (direct connect to HBA) while an attached
external JBOD with an expander have different slot identifier
methods.
How Has This Been Tested?
~~~~~~~~~~~~~~~~~~~~~~~~~
Testing was performed on a AMD EPYC based dual-server
high-availability multipath environment with multiple
HBAs per ZFS server and four SAS JBODs. The two primary
JBODs were multipath/cross-connected between the two
ZFS-HA servers. The secondary JBODs were daisy-chained
off of the primary JBODs using aligned SAS expander
channels (JBOD-0 expanderA--->JBOD-1 expanderA,
JBOD-0 expanderB--->JBOD-1 expanderB, etc).
Pools were created, exported and re-imported, imported
globally with 'zpool import -a -d /dev/disk/by-vdev'.
Low level udev debug outputs were traced to isolate
and resolve errors.
Result:
~~~~~~~
Initial testing of a previous version of this change
showed how reliance on userspace utilities like
'/usr/sbin/multipath' and '/usr/bin/lsscsi' were
exacerbated by increasing numbers of disks and JBODs.
With four 60-disk SAS JBODs and 240 disks the time to
process a udevadm trigger was 3 minutes 30 seconds
during which nearly all CPU cores were above 80%
utilization. By switching reliance on userspace
utilities to sysfs in this version, the udevadm
trigger processing time was reduced to 12.2 seconds
and negligible CPU load.
This patch also fixes few shellcheck complains.
Reviewed-by: Gabriel A. Devenyi <gdevenyi@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Jeff Johnson <jeff.johnson@aeoncomputing.com>
Signed-off-by: Jeff Johnson <jeff.johnson@aeoncomputing.com>
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Closes#11526
Starting in Linux 5.10, trying to write to /dev/{null,zero} errors out.
Prefer to inform people when this happens rather than hoping they guess
what's wrong.
Reviewed-by: Antonio Russo <aerusso@aerusso.net>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes: #11991
The receive-o-x_props_override test case reliably fails on the
FreeBSD main builders (but not on Linux), until the root cause is
understood add this test to the FreeBSD exception list.
On Linux the alloc_class_012_pos test case may occasionally fail.
This is a known false positive which has also been added to the
Linux exception list until the test can be made entirely reliable.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12272
When cleaning up a test case standardize on using the convention:
datasetexists $ds && destroy_dataset $ds <flags>
By using 'destroy_dataset' instead of 'log_must zfs destroy' we ensure
that the destroy is retried in the event that a ZFS volume is busy.
This helps ensures ensure tests are fully cleaned up and prevents false
positive test failures on Linux.
Note that all of the tests which used 'zfs destroy' in cleanup have
been updated even if they don't use volumes. This was done to
clearly establish the expected convention.
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12663
cloud-init added a hook which triggers on every device add/rm
event, which results in holding open devices for a while after
they're created/destroyed.
So let's shove an exclusion rule for that into the GH workflows
until it gets fixed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12644Closes#12669
We use docker image instead.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#12529
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#12529
Libera have made a webchat client available. This change builds on #12127.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jonathon Fernyhough <jonathon@m2x.dev>
Closes#12251
While Libera doesn't yet have a webchat client, we should at least
direct them to the right network. Once a webchat client is available,
we can direct them to it.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#12127
Compiling with gcc 11.1.0 produces three new warnings.
Change the code slightly to avoid them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#12130Closes#12188Closes#12237
As of the Linux 5.9 kernel a fallthrough macro has been added which
should be used to anotate all intentional fallthrough paths. Once
all of the kernel code paths have been updated to use fallthrough
the -Wimplicit-fallthrough option will because the default. To
avoid warnings in the OpenZFS code base when this happens apply
the fallthrough macro.
Additional reading: https://lwn.net/Articles/794944/
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12441