9079 race condition in starting and ending condesing thread for indirect vdevs
illumos/illumos-gate@667ec66f1b
The timeline of the race condition is the following:
[1] Thread A is about to finish condesing the first vdev in spa_condense_indirect_thread(),
so it calls the spa_condense_indirect_complete_sync() sync task which sets the
spa_condensing_indirect field to NULL. Waiting for the sync task to finish, thread A
sleeps until the txg is done. When this happens, thread A will acquire spa_async_lock
and set spa_condense_thread to NULL.
[2] While thread A waits for the txg to finish, thread B which is running spa_sync() checks
whether it should condense the second vdev in vdev_indirect_should_condense() by checking
the spa_condensing_indirect field which was set to NULL by spa_condense_indirect_thread()
from thread A. So it goes on and tries to spawn a new condensing thread in
spa_condense_indirect_start_sync() and the aforementioned assertions fails because thread A
has not set spa_condense_thread to NULL (which is basically the last thing it does before
returning).
The main issue here is that we rely on both spa_condensing_indirect and spa_condense_thread to
signify whether a condensing thread is running. Ideally we would only use one throughout the
codebase. In addition, for managing spa_condense_thread we currently use spa_async_lock which
basically tights condensing to scrubing when it comes to pausing and resuming those actions
during spa export.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
illumos/illumos-gate@667ec66f1b
The timeline of the race condition is the following:
[1] Thread A is about to finish condesing the first vdev in spa_condense_indirect_thread(),
so it calls the spa_condense_indirect_complete_sync() sync task which sets the
spa_condensing_indirect field to NULL. Waiting for the sync task to finish, thread A
sleeps until the txg is done. When this happens, thread A will acquire spa_async_lock
and set spa_condense_thread to NULL.
[2] While thread A waits for the txg to finish, thread B which is running spa_sync() checks
whether it should condense the second vdev in vdev_indirect_should_condense() by checking
the spa_condensing_indirect field which was set to NULL by spa_condense_indirect_thread()
from thread A. So it goes on and tries to spawn a new condensing thread in
spa_condense_indirect_start_sync() and the aforementioned assertions fails because thread A
has not set spa_condense_thread to NULL (which is basically the last thing it does before
returning).
The main issue here is that we rely on both spa_condensing_indirect and spa_condense_thread to
signify whether a condensing thread is running. Ideally we would only use one throughout the
codebase. In addition, for managing spa_condense_thread we currently use spa_async_lock which
basically tights condensing to scrubing when it comes to pausing and resuming those actions
during spa export.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
9075 Improve ZFS pool import/load process and corrupted pool recovery
illumos/illumos-gate@6f7938128a
Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:
https://www.illumos.org/issues/7638: Refactor spa_load_impl into several functions
https://www.illumos.org/issues/8961: SPA load/import should tell us why it failed
https://www.illumos.org/issues/7277: zdb should be able to print zfs_dbgmsg's
To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.
The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.
The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.
When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.
This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.
With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
Of data, this feature is for now restricted to a read-only import.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
Trying to grab locks during cngrab() when entering the debugger is
deadlock prone as all other CPUs are already halted (and thus unable
to release locks) when cngrab() is invoked. One could instead use
try-locks. However, the case that the try-lock fails still has to
be handled. In addition, if the try-lock works it doesn't provide
any greater ordering guarantees than is already provided by entering
and exiting DDB. It is simpler to define a simpler path for the
case that the try-lock would fail and always use that when entering
DDB. Messing with timers, etc. when entering DDB is dubious even if
the try-lock succeeds.
This patch attempts to use the smallest possible set of operations to
grab the vt(4) console when entering DDB without using any locks.
Reviewed by: emaste
Tested by: Matthew Macy
MFC after: 1 week
9075 Improve ZFS pool import/load process and corrupted pool recovery
illumos/illumos-gate@6f7938128a
Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:
https://www.illumos.org/issues/7638: Refactor spa_load_impl into several functions
https://www.illumos.org/issues/8961: SPA load/import should tell us why it failed
https://www.illumos.org/issues/7277: zdb should be able to print zfs_dbgmsg's
To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.
The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.
The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.
When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.
This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.
With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
Of data, this feature is for now restricted to a read-only import.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
Instead of the global namespace, let's attach these to the cli module. Other
users, including the "local" module, can attach functions to the cli module
at will to add other cli commands and things will still Just Work.
This distills down the candidates for functions that may be invoked via the
cli to a minimal set (boot, autoboot, arguments), rather than any function
that happens to live in the global lua namespace.
This consolidates all of the DDP state in one place. Also, the code has
now been fixed to ensure that DDP state is only accessed for DDP
connections. This should not be a functional change but makes it cleaner
and easier to add state for other TOE socket modes in the future.
MFC after: 1 month
Sponsored by: Chelsio Communications
This will be the translation layer for varargs -> cmd_name, argv for cli
commands. We reserve the right to break exactly what the varargs inclulde,
but this gives us a stable way to pull the arguments out of varargs.
illumos/illumos-gate@add927f8c8
Reported on the ZFSonLinux https://github.com/zfsonlinux/zfs/issues/4843,
fixed by https://github.com/zfsonlinux/zfs/pull/6339:
If we are in the middle of an incremental zfs receive, the child .../%recv
will exist. If you concurrently run zfs promote .../%recv, it will "work",
but then zfs gets confused. For example, there's no obvious way to destroy
the containing filesystem (because it is now a clone of its invisible child).
Attempting to do this promote should be an error. We could fix this by
having zfs_ioc_promote() check if zc_name contains a %, similar to
zfs_ioc_rename().
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
illumos/illumos-gate@add927f8c8
Reported on the ZFSonLinux https://github.com/zfsonlinux/zfs/issues/4843,
fixed by https://github.com/zfsonlinux/zfs/pull/6339:
If we are in the middle of an incremental zfs receive, the child .../%recv
will exist. If you concurrently run zfs promote .../%recv, it will "work",
but then zfs gets confused. For example, there's no obvious way to destroy
the containing filesystem (because it is now a clone of its invisible child).
Attempting to do this promote should be an error. We could fix this by
having zfs_ioc_promote() check if zc_name contains a %, similar to
zfs_ioc_rename().
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
This module will, in the not-so-distant future, grow functionality for
reducing boilerplate in functions that implement cli commands. It will
likely also house most in-tree cli commands.
illumos/illumos-gate@f4c1745bd6
Illumos 4080 allows "zpool clear" to work on readonly pools: i don't think
this is the intended behaviour, we shouldn't be allowed to clear readonly
pools. Probably.
A fix is already in the ZFS on Linux repository to addess this issue:
92e43c1718
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
illumos/illumos-gate@f4c1745bd6
Illumos 4080 allows "zpool clear" to work on readonly pools: i don't think
this is the intended behaviour, we shouldn't be allowed to clear readonly
pools. Probably.
A fix is already in the ZFS on Linux repository to addess this issue:
92e43c1718
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
8408 dsl_props_set_sync_impl() does not handle nested nvlists correctly
illumos/illumos-gate@85723e5eec
When iterating over the input nvlist in dsl_props_set_sync_impl() when we
don't preserve the nvpair name before looking up ZPROP_VALUE, so when we
later go to process it nvpair_name() is always "value" instead of the actual
property name.
This results in a couple of bugs in the recv code:
- received properties are not restored correctly when failing to receive
an incremental send stream
- received properties are not completely replaced by the new ones when
successfully receiving an incremental send stream
This was discovered on ZFS on Linux (fixed in
5f1346c299)
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
illumos/illumos-gate@85723e5eec
When iterating over the input nvlist in dsl_props_set_sync_impl() when we
don't preserve the nvpair name before looking up ZPROP_VALUE, so when we
later go to process it nvpair_name() is always "value" instead of the actual
property name.
This results in a couple of bugs in the recv code:
- received properties are not restored correctly when failing to receive
an incremental send stream
- received properties are not completely replaced by the new ones when
successfully receiving an incremental send stream
This was discovered on ZFS on Linux (fixed in
5f1346c299)
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
illumos/illumos-gate@f02c28e434
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Toomas Soome <tsoome@me.com>
illumos/illumos-gate@46ac8fdfc5
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Toomas Soome <tsoome@me.com>
illumos/illumos-gate@46ac8fdfc5
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Toomas Soome <tsoome@me.com>
illumos/illumos-gate@e144c4e6c9
Currently `zdb` consistently fails to examine non-idle pools as it fails
during the `spa_load()` process. The main problem seems to be that
`spa_load_verify()` fails as can be seen below:
$ sudo zdb -d -G dcenter
zdb: can't open 'dcenter': I/O error
ZFS_DBGMSG(zdb):
spa_open_common: opening dcenter
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
spa_load(dcenter): using uberblock with txg=40824950
spa_load(dcenter): UNLOADING
spa_load(dcenter): RELOADING
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
spa_load(dcenter): using uberblock with txg=40824952
spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
spa_load(dcenter): UNLOADING
This change makes `spa_load_verify()` a dryrun when ran from `zdb`. This is
done by creating a global flag in zfs and then setting it in `zdb`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
These are a convenience for bhyve's debug server to use a single
ioctl for 'g' and 'G' rather than a loop of individual get/set
ioctl requests.
Reviewed by: grehan
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D14074
illumos/illumos-gate@e144c4e6c9
Currently `zdb` consistently fails to examine non-idle pools as it fails
during the `spa_load()` process. The main problem seems to be that
`spa_load_verify()` fails as can be seen below:
$ sudo zdb -d -G dcenter
zdb: can't open 'dcenter': I/O error
ZFS_DBGMSG(zdb):
spa_open_common: opening dcenter
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
spa_load(dcenter): using uberblock with txg=40824950
spa_load(dcenter): UNLOADING
spa_load(dcenter): RELOADING
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
spa_load(dcenter): using uberblock with txg=40824952
spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
spa_load(dcenter): UNLOADING
This change makes `spa_load_verify()` a dryrun when ran from `zdb`. This is
done by creating a global flag in zfs and then setting it in `zdb`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
illumos/illumos-gate@3ee8c80c74
When we fail to open or import a storage pool, we typically don't get any
additional diagnostic information, just "no pool found" or "can not import".
While there may be no additional user-consumable information, we should at
least make this situation easier to debug/diagnose for developers and support.
For example, we could start by using `zfs_dbgmsg()` to log each thing that we
try when importing, and which things failed. E.g. "tried uberblock of txg X
from label Y of device Z". Also, we could log each of the stages that we go
through in `spa_load_impl()`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
illumos/illumos-gate@3ee8c80c74
When we fail to open or import a storage pool, we typically don't get any
additional diagnostic information, just "no pool found" or "can not import".
While there may be no additional user-consumable information, we should at
least make this situation easier to debug/diagnose for developers and support.
For example, we could start by using `zfs_dbgmsg()` to log each thing that we
try when importing, and which things failed. E.g. "tried uberblock of txg X
from label Y of device Z". Also, we could log each of the stages that we go
through in `spa_load_impl()`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
illumos/illumos-gate@1fd3785ff6
spa_load_impl has grown out of proportions. It is currently over 700
lines long and makes it very hard to follow or debug the import process
even for experienced ZFS developers. The objective is to split it up
in a series of well commented functions.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
illumos/illumos-gate@1fd3785ff6
spa_load_impl has grown out of proportions. It is currently over 700
lines long and makes it very hard to follow or debug the import process
even for experienced ZFS developers. The objective is to split it up
in a series of well commented functions.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
illumos/illumos-gate@36a64e6284
To prevent kmem_cache reaping from blocking other system resources, turn
kmem_cache_reap_now() (which blocks) into kmem_cache_reap_soon(). Callers
to kmem_cache_reap_soon() should use kmem_cache_reap_active(), which
exploits #9017's new taskq_empty().
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Author: Tim Kordas <tim.kordas@joyent.com>
FreeBSD does not use taskqueue for kmem caches reaping, so this change
is less dramatic then it is on Illumos, just limiting reaping to 1 time
per second. It may possibly be improved later, if needed.
illumos/illumos-gate@36a64e6284
To prevent kmem_cache reaping from blocking other system resources, turn
kmem_cache_reap_now() (which blocks) into kmem_cache_reap_soon(). Callers
to kmem_cache_reap_soon() should use kmem_cache_reap_active(), which
exploits #9017's new taskq_empty().
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Author: Tim Kordas <tim.kordas@joyent.com>
illumos/illumos-gate@f06dce2c1f
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Gordon Ross <gordon.w.ross@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Andrew Stormont <astormont@racktopsystems.com>
Mostly const-correctness fixes. There were also some variable-shadowing,
unused variable, and a couple of sockaddr type-correctness changes. I also had
trouble with cast-align warnings. I was able to prove that one of them was a
false positive. But ultimately I had to disable the warning program-wide to
deal with the others.
Reviewed by: cem
MFC after: 3 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D14460
illumos/illumos-gate@f06dce2c1f
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Gordon Ross <gordon.w.ross@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Andrew Stormont <astormont@racktopsystems.com>
To minimize the time spent scanning all of the directories in pass 2
(Check Pathnames), fsck uses a search order based on the location
of their first block. Zero length directories have no first block,
so the array being used to hold the block numbers of directory
inodes was of zero length. Thus a lookup was done past the end of
the array getting at best a random value and at worst a segment
fault. For zero length directories, this change allocates a one
element block array and initializes it to zero. The effect is that
all zero length directories are handled first in pass 2.
Reviewed by: brooks
Differential Revision: https://reviews.freebsd.org/D14163
This seems to have been arbitrary; bootlock_password and password don't seem
to have any documented length restrictions, and loader(8) probably shouldn't
care about whatever GELI passphrase length restrictions might exist.
Reported by: Kalle Carlbark <kalle.carlbark+freebsd@kcbark.net>
As noted in D14267 load_elf.c has a variety of indentation styles. Move
to standard 8 column hard tab indents, 4 space second level indents.
Also includes some whitespace cleanups found by clang-format.
The current route(8) manpage shows that "flush" is an argument to
the optional -n flag, rather than a separate subcommand. Correct
this to properly show flush as a route subcommand.
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Reviewed by: rgrimes
Differential Revision: https://reviews.freebsd.org/D14401
Only require a gateway to be specified on a route add request. On
a route change request that does not specify the gateway, the
gateway will remain the same. This allows changing other route
parameters without having to re-specifying the gateway, like in
"route change 10.0.0.0/8 -mtu 9000".
Update the route(8) manpage to explicitly call out this usage
as being supported.
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Reviewed By: eugen (rtsock.c change), rgrimes
Differential Revision: https://reviews.freebsd.org/D14291
