Commit Graph

104 Commits

Author SHA1 Message Date
Ryan Moeller
439dc034e9 FreeBSD: Implement sysctl for fletcher4 impl
There is a tunable to select the fletcher 4 checksum implementation on
Linux but it was not present in FreeBSD.

Implement the sysctl handler for FreeBSD and use ZFS_MODULE_PARAM_CALL
to provide the tunable on both platforms.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11270
2020-12-11 10:29:01 -08:00
Paul Dagnelie
60a4c7d2a2
Implement memory and CPU hotplug
ZFS currently doesn't react to hotplugging cpu or memory into the 
system in any way. This patch changes that by adding logic to the ARC 
that allows the system to take advantage of new memory that is added 
for caching purposes. It also adds logic to the taskq infrastructure 
to support dynamically expanding the number of threads allocated to a 
taskq.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Ahrens <matthew.ahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #11212
2020-12-10 14:09:23 -08:00
Ryan Moeller
e0716250bf
FreeBSD: Do zcommon_init sooner to avoid FPU panic
There has been a panic affecting some system configurations where the
thread FPU context is disturbed during the fletcher 4 benchmarks,
leading to a panic at boot.

module_init() registers zcommon_init to run in the last subsystem
(SI_SUB_LAST).  Running it as soon as interrupts have been configured
(SI_SUB_INT_CONFIG_HOOKS) makes sure we have finished the benchmarks
before we start doing other things.

While it's not clear *how* the FPU context was being disturbed, this
does seem to avoid it.

Add a module_init_early() macro to run zcommon_init() at this earlier
point on FreeBSD.  On Linux this is defined as module_init().

Authored by: Konstantin Belousov <kib@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11302
2020-12-09 21:29:00 -08:00
Brian Behlendorf
4352edaafb
Linux: Fix ZFS_ENTER/ZFS_EXIT/ZFS_VERFY_ZP usage
The ZFS_ENTER/ZFS_EXIT/ZFS_VERFY_ZP macros should not be used
in the Linux zpl_*.c source files.  They return a positive error
value which is correct for the common code, but not for the Linux
specific kernel code which expects a negative return value.  The
ZPL_ENTER/ZPL_EXIT/ZPL_VERFY_ZP macros should be used instead.

Furthermore, the ZPL_EXIT macro has been updated to not call the
zfs_exit_fs() function.  This prevents a possible deadlock which
can occur when a snapshot is automatically unmounted because the
zpl_show_devname() must never wait on in progress automatic
snapshot unmounts.

Reviewed-by: Adam Moss <c@yotes.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11169 
Closes #11201
2020-11-14 10:19:00 -08:00
Mateusz Guzik
1a0b4f566c
G/C struct znode -> z_moved
The field is yet another leftover from unsupported zfs_znode_move.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11186
2020-11-10 12:42:47 -08:00
Coleman Kane
ae15f1c1d8 Linux 5.10 compat: check_disk_change() removed
Kernel 5.10 removed check_disk_change() in favor of callers using
the faster bdev_check_media_change() instead, and explicitly forcing
bdev revalidation when they desire that behavior. To preserve prior
behavior, I have wrapped this into a zfs_check_media_change() macro
that calls an inline function for the new API that mimics the old
behavior when check_disk_change() doesn't exist, and just calls
check_disk_change() if it exists.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #11085
2020-11-02 22:01:19 +00:00
Christian Schwarz
ab8c935ea6
zfs_vnops: make zfs_get_data OS-independent
Move zfs_get_data() in to platform-independent code. The only
platform-specific aspect of it is the way we release an inode 
(Linux) / vnode_t (FreeBSD). I am not aware of a platform that
could be supported by ZFS that couldn't implement zfs_rele_async 
itself. It's sibling zvol_get_data already is platform-independent.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes #10979
2020-11-02 12:07:07 -08:00
Mateusz Guzik
09eb36ce3d
Introduce CPU_SEQID_UNSTABLE
Current CPU_SEQID users don't care about possibly changing CPU ID, but
enclose it within kpreempt disable/enable in order to fend off warnings
from Linux's CONFIG_DEBUG_PREEMPT.

There is no need to do it. The expected way to get CPU ID while allowing
for migration is to use raw_smp_processor_id.

In order to make this future-proof this patch keeps CPU_SEQID as is and
introduces CPU_SEQID_UNSTABLE instead, to make it clear that consumers
explicitly want this behavior.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11142
2020-11-02 11:51:12 -08:00
Matthew Macy
8583540c6e
Consolidate zfs_holey and zfs_access
The zfs_holey() and zfs_access() functions can be made common
to both FreeBSD and Linux.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #11125
2020-10-31 09:40:08 -07:00
Matthew Macy
5fa356ea44
Remove UIO_ZEROCOPY functions structures
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
2020-10-30 10:00:33 -07:00
Matthew Macy
e53d678d4a
Share zfs_fsync, zfs_read, zfs_write, et al between Linux and FreeBSD
The zfs_fsync, zfs_read, and zfs_write function are almost identical
between Linux and FreeBSD.  With a little refactoring they can be
moved to the common code which is what is done by this commit.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #11078
2020-10-21 14:08:06 -07:00
Brian Behlendorf
d0249a4bd0
Replace ZFS on Linux references with OpenZFS
This change updates the documentation to refer to the project
as OpenZFS instead ZFS on Linux.  Web links have been updated
to refer to https://github.com/openzfs/zfs.  The extraneous
zfsonlinux.org web links in the ZED and SPL sources have been
dropped.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11007
2020-10-08 20:10:13 -07:00
Ryan Moeller
4d55ea811d
Throw const on some strings
In C, const indicates to the reader that mutation will not occur.
It can also serve as a hint about ownership.

Add const in a few places where it makes sense.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10997
2020-10-02 17:44:10 -07:00
Matthew Macy
7b8363d7f0
FreeBSD: Add support for procfs_list
The procfs_list interface is required by several kstats. Implement
this functionality for FreeBSD to provide access to these kstats.
                           
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10890
2020-09-23 16:43:51 -07:00
George Wilson
c494aa7f57
vdev_ashift should only be set once
== Motivation and Context

The new vdev ashift optimization prevents the removal of devices when
a zfs configuration is comprised of disks which have different logical
and physical block sizes. This is caused because we set 'spa_min_ashift'
in vdev_open and then later call 'vdev_ashift_optimize'. This would
result in an inconsistency between spa's ashift calculations and that
of the top-level vdev.

In addition, the optimization logical ignores the overridden ashift
value that would be provided by '-o ashift=<val>'.

== Description

This change reworks the vdev ashift optimization so that it's only
set the first time the device is configured. It still allows the
physical and logical ahsift values to be set every time the device
is opened but those values are only consulted on first open.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-Issue: DLPX-71831
Closes #10932
2020-09-18 12:13:47 -07:00
Toomas Soome
1db9e6e4e4
zfs label bootenv should store data as nvlist
nvlist does allow us to support different data types and systems.

To encapsulate user data to/from nvlist, the libzfsbootenv library is
provided.

Reviewed-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Toomas Soome <tsoome@me.com>
Closes #10774
2020-09-15 15:42:27 -07:00
Matthew Macy
ac6e5fb202
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
2020-09-03 20:04:09 -07:00
Ryan Moeller
7b4e27232d
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
2020-09-01 16:14:16 -07:00
Brian Behlendorf
3e29e1971b
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
2020-08-29 20:57:45 -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
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
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
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
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 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
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 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
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 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
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
65c7cc49bf Mark functions as static
Mark functions used only in the same translation unit as static. This
only includes functions that do not have a prototype in a header file
either.

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 12:20:38 -07:00
adilger
f734301d22
linux: add basic fallocate(mode=0/2) compatibility
Implement semi-compatible functionality for mode=0 (preallocation)
and mode=FALLOC_FL_KEEP_SIZE (preallocation beyond EOF) for ZPL.

Since ZFS does COW and snapshots, preallocating blocks for a file
cannot guarantee that writes to the file will not run out of space.
Even if the first overwrite was guaranteed, it would not handle any
later overwrite of blocks due to COW, so strict compliance is futile.
Instead, make a best-effort check that at least enough free space is
currently available in the pool (with a bit of margin), then create
a sparse file of the requested size and continue on with life.

This does not handle all cases (e.g. several fallocate() calls before
writing into the files when the filesystem is nearly full), which
would require a more complex mechanism to be implemented, probably
based on a modified version of dmu_prealloc(), but is usable as-is.

A new module option zfs_fallocate_reserve_percent is used to control
the reserve margin for any single fallocate call.  By default, this
is 110% of the requested preallocation size, so an additional 10% of
available space is reserved for overhead to allow the application a
good chance of finishing the write when the fallocate() succeeds.
If the heuristics of this basic fallocate implementation are not
desirable, the old non-functional behavior of returning EOPNOTSUPP
for calls can be restored by setting zfs_fallocate_reserve_percent=0.

The parameter of zfs_statvfs() is changed to take an inode instead
of a dentry, since no dentry is available in zfs_fallocate_common().

A few tests from @behlendorf cover basic fallocate functionality.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Issue #326
Closes #10408
2020-06-18 11:22:11 -07:00
Matthew Macy
8056a75672
Disambiguate condvar API contract
On Illumos callers of cv_timedwait and cv_timedwait_hires
can't distinguish between whether or not the cv was signaled
or the call timed out. Illumos handles this (for some definition
of handles) by calling cv_signal in the return path if we were
signaled but the return value indicates instead that we timed
out. This would make sense if it were possible to query the the
cv for its net signal disposition. However, this isn't possible
and, in spite of the fact that there are places in the code that
clearly take a different and incompatible path if a timeout value
is indicated, this distinction appears to be rather subtle to most
developers. This problem is further compounded by the fact that on
Linux, calling cv_signal in the return path wouldn't even do the
right thing unless there are other waiters.

Since it is possible for the caller to independently determine how
much time is remaining but it is not possible to query if the cv
was in fact signaled, prioritizing signalling over timeout seems
like a cleaner solution. In addition, judging from usage patterns
within the code itself, it is also less error prone.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10471
2020-06-18 10:17:50 -07:00
Jorgen Lundman
883a40fff4
Add convenience wrappers for common uio usage
The macOS uio struct is opaque and the API must be used, this
makes the smallest changes to the code for all platforms.

Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes #10412
2020-06-14 10:09:55 -07:00
Andrea Gelmini
dd4bc569b9
Fix typos
Correct various typos in the comments and tests.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #10423
2020-06-09 21:24:09 -07:00
Michael Niewöhner
32f26eaa70
Move GFP flags kernel compatibility code
Move the GFP flags kernel compat code from c file to kmem header.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Closes #10424
2020-06-08 16:33:46 -07:00