Commit Graph

119 Commits

Author SHA1 Message Date
Ryan Moeller
127daad223 Avoid possibility of division by zero
When hz > 1000, msec / (1000 / hz) results in division by zero.

I found somewhere in FreeBSD using howmany(msec * hz, 1000) to convert
ms to ticks, avoiding the potential for a zero in the divisor.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10894
2020-09-09 10:26:03 -07:00
Alexander Richardson
e28635396a Fixes for running FreeBSD buildworld on Linux/macOS hosts
Adding an #ifdef __FreeBSD__ to a FreeBSD-specific header may seem odd,
but these headers are used on non-FreeBSD systems during the bootstrap
tools phase.
Originally submitted downstream as https://reviews.freebsd.org/D26193

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
Closes #10863
2020-09-09 10:21:11 -07:00
Matthew Macy
36f36610c3 Replace cv_{timed}wait_sig with cv_{timed}wait_idle where appropriate
There are a number of places where cv_?_sig is used simply for
accounting purposes but the surrounding code has no ability to
cope with actually receiving a signal. On FreeBSD it is possible
to send signals to individual kernel threads so this could
enable undesirable behavior.

This patch adds routines on Linux that will do the same idle
accounting as _sig without making the task interruptible. On
FreeBSD cv_*_idle  are all aliases for cv_*

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10843
2020-09-09 10:21:01 -07:00
Ryan Moeller
76a157f004 Add 'zfs rename -u' to rename without remounting
Allow to rename file systems without remounting if it is possible.
It is possible for file systems with 'mountpoint' property set to
'legacy' or 'none' - we don't have to change mount directory for them.
Currently such file systems are unmounted on rename and not even
mounted back.

This introduces layering violation, as we need to update
'f_mntfromname' field in statfs structure related to mountpoint (for
the dataset we are renaming and all its children).

In my opinion it is worth it, as it allow to update FreeBSD in even
cleaner way - in ZFS-only configuration root file system is ZFS file
system with 'mountpoint' property set to 'legacy'. If root dataset is
named system/rootfs, we can snapshot it (system/rootfs@upgrade), clone
it (system/oldrootfs), update FreeBSD and if it doesn't boot we can
boot back from system/oldrootfs and rename it back to system/rootfs
while it is mounted as /. Before it was not possible, because
unmounting / was not possible.

Authored by: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: Matt Macy <mmacy@freebsd.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10839
2020-09-03 16:16:15 -07:00
Ryan Moeller
d6a779a278 FreeBSD: Simplify INGLOBALZONE
FreeBSD's previous ZFS implemented INGLOBALZONE(thread) as
(!jailed((thread)->td_ucred)) and passed curthread to INGLOBALZONE.

We pass curproc instead of curthread, so we can achieve the same effect
with (!jailed((proc)->p_ucred)).  The implementation is trivial enough
to fit on a single line in a define.  We don't really need a whole
separate function for something that's already macros all the way down.

Eliminate in_globalzone.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10851
2020-09-03 16:15:59 -07:00
Ryan Moeller
bbba0b7f93 FreeBSD: Define crgetzoneid appropriately
The previous ZFS implementation on FreeBSD had ifdefs to use jailed()
instead of crgetzoneid() in dsl_dir.c, however we can simply provide an
appropriate definition of crgetzoneid for the same effect.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10851
2020-09-03 16:15:53 -07:00
Brian Behlendorf
c6ee83893e Linux 5.9 compat: NR_SLAB_RECLAIMABLE
Commit dcdc12e added compatibility code to treat NR_SLAB_RECLAIMABLE_B
as if it were the same as NR_SLAB_RECLAIMABLE.  However, the new value
is in bytes while the old value was in pages which means they are not
interchangeable.

The only place the reclaimable slab size is used is as a component of
the calculation done by arc_free_memory().  This function returns the
amount of memory the ARC considers to be free or reclaimable at little
cost.  Rather than switch to a new interface to get this value it has
been removed it from the calculation.  It is normally a minor component
compared to the number of inactive or free pages, and removing it
aligns the behavior with the FreeBSD version of arc_free_memory().

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10834
2020-08-30 14:18:50 -07:00
Toomas Soome
510179f086 Remove pragma ident lines
The #pragma ident is a historical relic and not needed any more, this
pragma is actually unknown for common compilers and is only causing
trouble.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Toomas Soome <tsoome@me.com>
Closes #10810
2020-08-27 16:06:39 -07:00
Ryan Moeller
6fe3498ca3
Import vdev ashift optimization from FreeBSD
Many modern devices use physical allocation units that are much
larger than the minimum logical allocation size accessible by
external commands. Two prevalent examples of this are 512e disk
drives (512b logical sector, 4K physical sector) and flash devices
(512b logical sector, 4K or larger allocation block size, and 128k
or larger erase block size). Operations that modify less than the
physical sector size result in a costly read-modify-write or garbage
collection sequence on these devices.

Simply exporting the true physical sector of the device to ZFS would
yield optimal performance, but has two serious drawbacks:

 1. Existing pools created with devices that have different logical
    and physical block sizes, but were configured to use the logical
    block size (e.g. because the OS version used for pool construction
    reported the logical block size instead of the physical block
    size) will suddenly find that the vdev allocation size has
    increased. This can be easily tolerated for active members of
    the array, but ZFS would prevent replacement of a vdev with
    another identical device because it now appears that the smaller
    allocation size required by the pool is not supported by the new
    device.

 2. The device's physical block size may be too large to be supported
    by ZFS. The optimal allocation size for the vdev may be quite
    large. For example, a RAID controller may export a vdev that
    requires read-modify-write cycles unless accessed using 64k
    aligned/sized requests. ZFS currently has an 8k minimum block
    size limit.

Reporting both the logical and physical allocation sizes for vdevs
solves these problems. A device may be used so long as the logical
block size is compatible with the configuration. By comparing the
logical and physical block sizes, new configurations can be optimized
and administrators can be notified of any existing pools that are
sub-optimal.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Macy <mmacy@freebsd.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10619
2020-08-21 12:53:17 -07:00
Pavel Snajdr
772c69d230
Linux 5.7 compat: Include linux/sched.h in spl/sys/mutex.h
struct task_struct is needed for lockdep_off() in mutex.h

This has popped up after e616cb8daadf (in linux-5.7-rc7).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes #10741
2020-08-19 21:37:38 -07:00
Mariusz Zaborski
f2c027bd6a
FreeBSD: Add option to rewind checkpoint while importing root pool
This option is used by FreeBSD boot loader.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <oshogbo@vexillium.org>
Closes #10738
2020-08-19 17:19:42 -07:00
Matthew Macy
716b53d0a1
FreeBSD: Fix UNIX permissions checking
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10727
2020-08-18 09:57:07 -07:00
Ryan Moeller
009cc8e884
Make zc_nvlist_src_size limit tunable
We limit the size of nvlists passed to the kernel so a user cannot make
the kernel do an unreasonably large allocation.  On FreeBSD this limit
was 128 kiB, which turns out to be a bit too small when doing some
operations involving a large number of datasets or snapshots, for
example replication.

Make this limit tunable, with a platform-specific auto default.
Linux keeps its limit at KMALLOC_MAX_SIZE. FreeBSD uses 1/4 of the
system limit on user wired memory, which allows it to scale depending
on system configuration.

Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Issue #6572 
Closes #10706
2020-08-18 09:33:55 -07:00
Matthew Ahrens
994de7e4b7
Remove KMC_KMEM and KMC_VMEM
`KMC_KMEM` and `KMC_VMEM` are now unused since all SPL-implemented
caches are `KMC_KVMEM`.

KMC_KMEM: Given the default value of `spl_kmem_cache_kmem_limit`, we
don't use kmalloc to back the SPL caches, instead we use kvmalloc
(KMC_KVMEM).  The flag, module parameter, /proc entries, and associated
code are removed.

KMC_VMEM: This flag is not used, and kvmalloc() is always preferable to
vmalloc().  The flag, /proc entries, and associated code are removed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10673
2020-08-17 16:04:28 -07:00
Ryan Moeller
3c3d7c8a57
FreeBSD: Create taskq threads in appropriate proc
Stepping stone toward re-enabling spa_thread on FreeBSD.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10715
2020-08-17 11:01:19 -07:00
Coleman Kane
d817c17100 Linux 5.9 compat: make_request_fn replaced with submit_bio interface
The make_request_fn and associated API was replaced recently in a
Linux 5.9 merge, to replace its functionality with a new submit_bio
member in struct block_device_operations.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #10696
2020-08-11 13:37:33 -07:00
Coleman Kane
dcdc12e8ba Linux 5.9 compat: Update NR_SLAB_RECLAIMABLE to NR_SLAB_RECLAIMABLE_B
This change appears to primarily be a name change for the enum. Had
to update the test logic so that it works so long as either one of
these is present (favoring the newer one). Additionally, as this is
newer, it only shows up in node_page_item, so this commit doesn't
test zone_page_item for the same enum.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #10696
2020-08-11 13:35:20 -07:00
Matthew Ahrens
74e994ec63 Remove KM_NODEBUG
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:28:13 -07:00
Matthew Ahrens
c6f2b942be Remove KMC_NOMAGAZINE
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:28:07 -07:00
Matthew Ahrens
3c09f6949a Remove KMC_QCACHE
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:28:01 -07:00
Matthew Ahrens
d519c10575 Remove KMC_NOHASH
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:27:56 -07:00
Matthew Ahrens
f68af67a0c Remove KMC_NOTOUCH
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:27:46 -07:00
Matthew Ahrens
492db125dc Remove KMC_OFFSLAB
Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650
2020-08-05 10:25:37 -07:00
Matthew Macy
1b376d176e
FreeBSD: Add support for lockless lookup
Authored-by: mjg <mjg@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10657
2020-08-05 10:19:51 -07:00
Pavel Snajdr
309d20882f
Fix arc__wait__for__eviction tracepoint
3442c2a02d added new `arc_wait_for_eviction` tracepoint, which fails to
compile, when tracepoints are enabled.

The tracepoint definition begins with `DEFINE_ARC_WAIT_FOR_EVICTION_EVENT`
and is a multi-line definition, so this fixes the backslash
and parenthesis accordingly.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes #10669
2020-08-04 10:04:00 -07:00
Matthew Macy
47ed79ff60
Changes to make openzfs build within FreeBSD buildworld
A collection of header changes to enable FreeBSD to build
with vendored OpenZFS.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10635
2020-07-31 21:30:31 -07:00
Matthew Ahrens
3442c2a02d
Revise ARC shrinker algorithm
The ARC shrinker callback `arc_shrinker_count/_scan()` is invoked by the
kernel's shrinker mechanism when the system is running low on free
pages.  This happens via 2 code paths:

1. "direct reclaim": The system is attempting to allocate a page, but we
are low on memory.  The ARC shrinker callback is invoked from the
page-allocation code path.

2. "indirect reclaim": kswapd notices that there aren't many free pages,
so it invokes the ARC shrinker callback.

In both cases, the kernel's shrinker code requests that the ARC shrinker
callback release some of its cache, and then it measures how many pages
were released.  However, it's measurement of released pages does not
include pages that are freed via `__free_pages()`, which is how the ARC
releases memory (via `abd_free_chunks()`).  Rather, the kernel shrinker
code is looking for pages to be placed on the lists of reclaimable pages
(which is separate from actually-free pages).

Because the kernel shrinker code doesn't detect that the ARC has
released pages, it may call the ARC shrinker callback many times,
resulting in the ARC "collapsing" down to `arc_c_min`.  This has several
negative impacts:

1. ZFS doesn't use RAM to cache data effectively.

2. In the direct reclaim case, a single page allocation may wait a long
time (e.g. more than a minute) while we evict the entire ARC.

3. Even with the improvements made in 67c0f0dedc ("ARC shrinking blocks
reads/writes"), occasionally `arc_size` may stay above `arc_c` for the
entire time of the ARC collapse, thus blocking ZFS read/write operations
in `arc_get_data_impl()`.

To address these issues, this commit limits the ways that the ARC
shrinker callback can be used by the kernel shrinker code, and mitigates
the impact of arc_is_overflowing() on ZFS read/write operations.

With this commit:

1. We limit the amount of data that can be reclaimed from the ARC via
the "direct reclaim" shrinker.  This limits the amount of time it takes
to allocate a single page.

2. We do not allow the ARC to shrink via kswapd (indirect reclaim).
Instead we rely on `arc_evict_zthr` to monitor free memory and reduce
the ARC target size to keep sufficient free memory in the system.  Note
that we can't simply rely on limiting the amount that we reclaim at once
(as for the direct reclaim case), because kswapd's "boosted" logic can
invoke the callback an unlimited number of times (see
`balance_pgdat()`).

3. When `arc_is_overflowing()` and we want to allocate memory,
`arc_get_data_impl()` will wait only for a multiple of the requested
amount of data to be evicted, rather than waiting for the ARC to no
longer be overflowing.  This allows ZFS reads/writes to make progress
even while the ARC is overflowing, while also ensuring that the eviction
thread makes progress towards reducing the total amount of memory used
by the ARC.

4. The amount of memory that the ARC always tries to keep free for the
rest of the system, `arc_sys_free` is increased.

5. Now that the shrinker callback is able to provide feedback to the
kernel's shrinker code about our progress, we can safely enable
the kswapd hook. This will allow the arc to receive notifications
when memory pressure is first detected by the kernel. We also
re-enable the appropriate kstats to track these callbacks.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10600
2020-07-31 21:10:52 -07:00
Matthew Macy
27d96d2254
Rename refcount.h to zfs_refcount.h
Renamed to avoid conflicting with refcount.h when a different
implementation is already provided by the platform.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10620
2020-07-29 16:35:33 -07:00
Serapheim Dimitropoulos
843e9ca2e1
Introduce names for ZTHRs
When debugging issues or generally analyzing the runtime of
a system it would be nice to be able to tell the different
ZTHRs running by name rather than having to analyze their
stack.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10630
2020-07-29 09:43:33 -07:00
Matthew Macy
5678d3f593
Prefix zfs internal endian checks with _ZFS
FreeBSD defines _BIG_ENDIAN BIG_ENDIAN _LITTLE_ENDIAN
LITTLE_ENDIAN on every architecture. Trying to do
cross builds whilst hiding this from ZFS has proven
extremely cumbersome.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10621
2020-07-28 13:02:49 -07:00
Matthew Macy
e64cc4954c
Refactor ccompile.h to not include system headers
This is a step toward being able to vendor the OpenZFS code in FreeBSD.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10625
2020-07-25 20:09:50 -07:00
Matthew Macy
6d8da84106
Make use of ZFS_DEBUG consistent within kmod sources
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10623
2020-07-25 20:07:44 -07:00
Matthew Macy
f5b189f937
FreeBSD: Fixes required to build ZFS on PowerPC
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10622
2020-07-25 11:00:23 -07:00
Matthew Ahrens
4fbdb10c7b
remove kmem_cache module parameter KMC_EXPIRE_AGE
By default, `spl_kmem_cache_expire` is `KMC_EXPIRE_MEM`, meaning that
objects will be removed from kmem cache magazines by
`spl_kmem_cache_reap_now()`.

There is also a module parameter to change this to `KMC_EXPIRE_AGE`,
which establishes a maximum lifetime for objects to stay in the
magazine.  This setting has rarely, if ever, been used, and is not
regularly tested.

This commit removes the code for `KMC_EXPIRE_AGE`, and associated module
parameters.

Additionally, the unused module parameter
`spl_kmem_cache_obj_per_slab_min` is removed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10608
2020-07-24 09:39:26 -07:00
Matthew Ahrens
026e529cb3
Remove skc_reclaim, hdr_recl, kmem_cache shrinker
The SPL kmem_cache implementation provides a mechanism, `skc_reclaim`,
whereby individual caches can register a callback to be invoked when
there is memory pressure.  This mechanism is used in only one place: the
ARC registers the `hdr_recl()` reclaim function.  This function wakes up
the `arc_reap_zthr`, whose job is to call `kmem_cache_reap()` and
`arc_reduce_target_size()`.

The `skc_reclaim` callbacks are invoked only by shrinker callbacks and
`arc_reap_zthr`, and only callback only wakes up `arc_reap_zthr`.  When
called from `arc_reap_zthr`, waking `arc_reap_zthr` is a no-op.  When
called from shrinker callbacks, we are already aware of memory pressure
and responding to it.  Therefore there is little benefit to ever calling
the `hdr_recl()` `skc_reclaim` callback.

The `arc_reap_zthr` also wakes once a second, and if memory is low when
allocating an ARC buffer.  Therefore, additionally waking it from the
shrinker calbacks has little benefit.

The shrinker callbacks can be invoked very frequently, e.g. 10,000 times
per second.  Additionally, for invocation of the shrinker callback,
skc_reclaim is invoked many times.  Therefore, this mechanism consumes
significant amounts of CPU time.

The kmem_cache shrinker calls `spl_kmem_cache_reap_now()`, which,
in addition to invoking `skc_reclaim()`, does two things to attempt to
free pages for use by the system:
 1. Return free objects from the magazine layer to the slab layer
 2. Return entirely-free slabs to the page layer (i.e. free pages)

These actions apply only to caches implemented by the SPL, not those
that use the underlying kernel SLAB/SLUB caches.  The SPL caches are
used for objects >=32KB, which are primarily linear ABD's cached in the
DBUF cache.

These actions (freeing objects from the magazine layer and returning
entirely-free slabs) are also taken whenever a `kmem_cache_free()` call
finds a full magazine.  So there would typically be zero entirely-free
slabs, and the number of objects in magazines is limited (typically no
more than 64 objects per magazine, and there's one magazine per CPU).
Therefore the benefit of `spl_kmem_cache_reap_now()`, while nonzero, is
modest.

We also call `spl_kmem_cache_reap_now()` from the `arc_reap_zthr`, when
memory pressure is detected.  Therefore, calling
`spl_kmem_cache_reap_now()` from the kmem_cache shrinker is not needed.

This commit removes the `skc_reclaim` mechanism, its only callback
`hdr_recl()`, and the kmem_cache shrinker callback.

Reviewed-By: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10576
2020-07-19 09:58:30 -07:00
Matthew Macy
23c871671c
FreeBSD: zfs commands backward compatibility
Update the zfs commands such that they're backwards compatible with
the version of ZFS is the base FreeBSD.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10542
2020-07-15 21:32:50 -07:00
Brian Atkinson
e4d3d77684
Fixing gang ABD child removal race condition
On linux the list debug code has been setting off a failure when
checking that the node->next->prev value is pointing back at the node.
At times this check evaluates to 0xdead. When removing a child from a
gang ABD we must acquire the child's abd_mtx to make sure that the
same ABD is not being added to another gang ABD while it is being
removed from a gang ABD. This fixes a race condition when checking
if an ABDs link is already active and part of another gang ABD before
adding it to a gang.

Added additional debug code for the gang ABD in abd_verify() to make
sure each child ABD has active links. Also check to make sure another
gang ABD is not added to a gang ABD.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes #10511
2020-07-14 11:04:35 -07:00
Matthew Ahrens
e59a377a8f
filesystem_limit/snapshot_limit is incorrectly enforced against root
The filesystem_limit and snapshot_limit properties limit the number of
filesystems or snapshots that can be created below this dataset.
According to the manpage, "The limit is not enforced if the user is
allowed to change the limit."  Two types of users are allowed to change
the limit:

1. Those that have been delegated the `filesystem_limit` or
`snapshot_limit` permission, e.g. with
`zfs allow USER filesystem_limit DATASET`.  This works properly.

2. A user with elevated system privileges (e.g. root).  This does not
work - the root user will incorrectly get an error when trying to create
a snapshot/filesystem, if it exceeds the `_limit` property.

The problem is that `priv_policy_ns()` does not work if the `cred_t` is
not that of the current process.  This happens when
`dsl_enforce_ds_ss_limits()` is called in syncing context (as part of a
sync task's check func) to determine the permissions of the
corresponding user process.

This commit fixes the issue by passing the `task_struct` (typedef'ed as
a `proc_t`) to syncing context, and then using `has_capability()` to
determine if that process is privileged.  Note that we still need to
pass the `cred_t` to syncing context so that we can check if the user
was delegated this permission with `zfs allow`.

This problem only impacts Linux.  Wrappers are added to FreeBSD but it
continues to use `priv_check_cred()`, which works on arbitrary `cred_t`.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #8226
Closes #10545
2020-07-11 17:18:02 -07:00
Matthew Macy
3933305eac
FreeBSD: Use a hash table for taskqid lookups
Previously a tqent could be recycled prematurely, update the
code to use a hash table for lookups to resolve this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10529
2020-07-11 17:13:45 -07:00
Matthew Macy
7ddb753d17
freebsd: changes necessary to coexist with dtrace in tree
Fix header conflicts when building zfs with openzfs as a vendor import.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10497
2020-07-01 09:10:08 -07:00
Matthew Ahrens
3c42c9ed84
Clean up OS-specific ARC and kmem code
OS-specific code (e.g. under `module/os/linux`) does not need to share
its code structure with any other operating systems.  In particular, the
ARC and kmem code need not be similar to the code in illumos, because we
won't be syncing this OS-specific code between operating systems.  For
example, if/when illumos support is added to the common repo, we would
add a file `module/os/illumos/zfs/arc_os.c` for the illumos versions of
this code.

Therefore, we can simplify the code in the OS-specific ARC and kmem
routines.

These changes do not impact system behavior, they are purely code
cleanup.  The changes are:

Arenas are not used on Linux or FreeBSD (they are always `NULL`), so
`heap_arena`, `zio_arena`, and `zio_alloc_arena` can be removed, along
with code that uses them.

In `arc_available_memory()`:
 * `desfree` is unused, remove it
 * rename `freemem` to avoid conflict with pre-existing `#define`
 * remove checks related to arenas
 * use units of bytes, rather than converting from bytes to pages and
   then back to bytes

`SPL_KMEM_CACHE_REAP` is unused, remove it.

`skc_reap` is unused, remove it.

The `count` argument to `spl_kmem_cache_reap_now()` is unused, remove
it.

`vmem_size()` and associated type and macros are unused, remove them.

In `arc_memory_throttle()`, use a less confusing variable name to store
the result of `arc_free_memory()`.

Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10499
2020-06-29 09:01:07 -07:00
Arvind Sankar
4d8e68c42f Avoid installing kernel headers on FreeBSD
The kernel headers are installed for DKMS on linux, so don't install
them unless we're building on linux.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10506
2020-06-27 17:40:14 -07:00
Brian Behlendorf
67b1362f04 Style fixes
* Fix cstyle issue in shrinker.h which exceeded 80 columns.
* Silence shellcheck warning in zpool.d/smart script.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2020-06-27 17:38:55 -07:00
Matthew Ahrens
270ece24b6
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions.  Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks.  The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.

Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback.  There are a few downsides to
this approach:

* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.

* The newer, "split" callback API is easier to understand, because each
callback has one purpose.

* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.

This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.

Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 10:27:02 -07:00
Serapheim Dimitropoulos
ec1fea4516
Use percpu_counter for obj_alloc counter of Linux-backed caches
A previous commit enabled the tracking of object allocations
in Linux-backed caches from the SPL layer for debuggability.
The commit is: 9a170fc6fe54f1e852b6c39630fe5ef2bbd97c16

Unfortunately, it also introduced minor performance regressions
that were highlighted by the ZFS perf test-suite. Within Delphix
we found that the regression would be from -1%, all the way up
to -8% for some workloads.

This commit brings performance back up to par by creating a
separate counter for those caches and making it a percpu in
order to avoid lock-contention.

The initial performance testing was done by myself, and the
final round was conducted by @tonynguien who was also the one
that discovered the regression and highlighted the culprit.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10397
2020-06-26 18:06:50 -07:00
Arvind Sankar
6b99fc0620 Fixes for make dist
Reduce the usage of EXTRA_DIST. If files are conditionally included in
_SOURCES, _HEADERS etc, automake is smart enough to dist all files that
could possibly be included, but this does not apply to EXTRA_DIST,
resulting in make dist depending on the configuration.

Add some files that were missing altogether in various Makefile's.

The changes to disted files in this commit (excluding deleted files):

+./cmd/zed/agents/README.md
+./etc/init.d/README.md
+./lib/libspl/os/freebsd/getexecname.c
+./lib/libspl/os/freebsd/gethostid.c
+./lib/libspl/os/freebsd/getmntany.c
+./lib/libspl/os/freebsd/mnttab.c
-./lib/libzfs/libzfs_core.pc
-./lib/libzfs/libzfs.pc
+./lib/libzfs/os/freebsd/libzfs_compat.c
+./lib/libzfs/os/freebsd/libzfs_fsshare.c
+./lib/libzfs/os/freebsd/libzfs_ioctl_compat.c
+./lib/libzfs/os/freebsd/libzfs_zmount.c
+./lib/libzutil/os/freebsd/zutil_compat.c
+./lib/libzutil/os/freebsd/zutil_device_path_os.c
+./lib/libzutil/os/freebsd/zutil_import_os.c
+./module/lua/README.zfs
+./module/os/linux/spl/README.md
+./tests/README.md
+./tests/zfs-tests/tests/functional/cli_root/zfs_clone/zfs_clone_rm_nested.ksh
+./tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh
+./tests/zfs-tests/tests/functional/inheritance/README.config
+./tests/zfs-tests/tests/functional/inheritance/README.state
+./tests/zfs-tests/tests/functional/rsend/rsend_016_neg.ksh
+./tests/zfs-tests/tests/perf/fio/sequential_readwrite.fio

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10501
2020-06-26 14:20:02 -07:00
Arvind Sankar
7513807320 Drop unnecessary srcdir paths
There's no need to specify the srcdir explicitly in _HEADERS and
EXTRA_DIST.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10493
2020-06-24 18:20:18 -07:00
Ryan Moeller
9192f27c1d
Add zfs_multihost_interval tunable handler for FreeBSD
This tunable required a handler to be implemented for
ZFS_MODULE_PARAM_CALL.

Add the handler so the tunable can be declared in common code.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10490
2020-06-23 13:32:42 -07:00
Arvind Sankar
0ce2de637b Add prototypes
Add prototypes/move prototypes to header files.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:21:32 -07:00
Arvind Sankar
c3fe42aabd Remove dead code
Delete unused functions.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:21:18 -07:00