The checks in nfsd_file_acquire() and nfsd_file_put() that directly
invoke filecache garbage collection are intended to keep cache
occupancy between a low- and high-watermark. The reason to limit the
capacity of the filecache is to keep filecache lookups reasonably
fast.

However, invoking garbage collection at those points has some
undesirable negative impacts. Files that are held open by NFSv4
clients often push the occupancy of the filecache over these
watermarks. At that point:

- Every call to nfsd_file_acquire() and nfsd_file_put() results in
  an LRU walk. This has the same effect on lookup latency as long
  chains in the hash table.
- Garbage collection will then run on every nfsd thread, causing a
  lot of unnecessary lock contention.
- Limiting cache capacity pushes out files used only by NFSv3
  clients, which are the type of files the filecache is supposed to
  help.

To address those negative impacts, remove the direct calls to the
garbage collector. Subsequent patches will address maintaining
lookup efficiency as cache capacity increases.
Suggested-by: Wang Yugui <wangyugui@e16-tech.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Without LRU item rotation, the shrinker visits only a few items on
the end of the LRU list, and those would always be long-term OPEN
files for NFSv4 workloads. That makes the filecache shrinker
completely ineffective.

Adopt the same strategy as the inode LRU by using LRU_ROTATE.
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

There have been reports of problems when running fstests generic/531
against Linux NFS servers with NFSv4. The NFS server that hosts the
test's SCRATCH_DEV suffers from CPU soft lock-ups during the test.
Analysis shows that:

fs/nfsd/filecache.c
 482                 ret = list_lru_walk(&nfsd_file_lru,
 483                                 nfsd_file_lru_cb,
 484                                 &head, LONG_MAX);

causes nfsd_file_gc() to walk the entire length of the filecache LRU
list every time it is called (which is quite frequently). The walk
holds a spinlock the entire time that prevents other nfsd threads
from accessing the filecache.

What's more, for NFSv4 workloads, none of the items that are visited
during this walk may be evicted, since they are all files that are
held OPEN by NFS clients.

Address this by ensuring that open files are not kept on the LRU
list.
Reported-by: Frank van der Linden <fllinden@amazon.com>
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=386Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Observe the operation of garbage collection and the lifetime of
filecache items.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Add a guardrail to prevent freeing memory that is still on a list.
This includes either a dispose list or the LRU list.

This is the sign of a bug, but this class of bugs can be detected
so that they don't endanger system stability, especially while
debugging.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

There has always been the capability of exporting filecache metrics
via /proc, but it was never hooked up. Let's surface these metrics
to enable better observability of the filecache.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

If nfsd_file_cache_init() is called after a shutdown, be sure the
stat counters are reset.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Refactor nfsd_file_gc() to use the new list_lru helper.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Refactor the invariant part of nfsd_file_lru_walk_list() into a
separate helper function.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

This is a measure of how long items stay in the filecache, to help
assess how efficient the cache is.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Surface the count of freed nfsd_file items.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Count the number of successful acquisitions that did not create a
file (ie, acquisitions that do not result in a compulsory cache
miss). This count can be compared directly with the reported hit
count to compute a hit ratio.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Surface the NFSD filecache's LRU list length to help field
troubleshooters monitor filecache issues.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

The call trace doesn't add much value, but it sure is noisy.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Fixes: 37324e6b ("SUNRPC: Cache deferral injection")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Variable len is being assigned a value zero and this is never
read, it is being re-assigned later. The assignment is redundant
and can be removed.

Cleans up clang scan-build warning:
fs/nfsd/nfsctl.c:636:2: warning: Value stored to 'len' is never read
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Add a blank space after ','.
Change 'succesful' to 'successful'.
Signed-off-by: Zhang Jiaming <jiaming@nfschina.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Capture file handles and how they map to local inodes. In particular,
NFSv4 PUTFH uses fh_verify() so we can now observe which file handles
are the target of OPEN, LOOKUP, RENAME, and so on.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Record not only the number of pages requested, but the number of
pages that were actually allocated, to get a measure of progress
(or lack thereof).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Instead of trusting that struct file_lock returns completely unchanged
after vfs_test_lock() when there's no conflicting lock, stash away our
nlm_lockowner reference so we can properly release it for all cases.

This defends against another file_lock implementation overwriting fl_owner
when the return type is F_UNLCK.
Reported-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Tested-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

I discovered that xdr_encode_bool() was returning the same address
that was passed in the @p parameter. The documenting comment states
that the intent is to return the address of the next buffer
location, just like the other "xdr_encode_*" helpers.

The result was the encoded results of NFSv3 PATHCONF operations were
not formed correctly.

Fixes: ded04a58 ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

We had a report from the spring Bake-a-thon of data corruption in some
nfstest_interop tests. Looking at the traces showed the NFS server
allowing a v3 WRITE to proceed while a read delegation was still
outstanding.

Currently, we only set NFSD_FILE_BREAK_* flags if
NFSD_MAY_NOT_BREAK_LEASE was set when we call nfsd_file_alloc.
NFSD_MAY_NOT_BREAK_LEASE was intended to be set when finding files for
COMMIT ops, where we need a writeable filehandle but don't need to
break read leases.

It doesn't make any sense to consult that flag when allocating a file
since the file may be used on subsequent calls where we do want to break
the lease (and the usage of it here seems to be reverse from what it
should be anyway).

Also, after calling nfsd_open_break_lease, we don't want to clear the
BREAK_* bits. A lease could end up being set on it later (more than
once) and we need to be able to break those leases as well.

This means that the NFSD_FILE_BREAK_* flags now just mirror
NFSD_MAY_{READ,WRITE} flags, so there's no need for them at all. Just
drop those flags and unconditionally call nfsd_open_break_lease every
time.
Reported-by: Olga Kornieskaia <kolga@netapp.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2107360
Fixes: 65294c1f (nfsd: add a new struct file caching facility to nfsd)
Cc: <stable@vger.kernel.org> # 5.4.x : bb283ca1 NFSD: Clean up the show_nf_flags() macro
Cc: <stable@vger.kernel.org> # 5.4.x
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Pull intel drm build fix from Rodrigo Vivi:
 "Our 'dim' flow has a problem with fixes of fixes getting missed. We
  need to take a look on that later.

  Meanwhile, please allow me to quickly propagate this fix for the
  32-bit build issue here upstream"

* tag 'drm-intel-fixes-2022-07-17' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915/ttm: fix 32b build

Merge tag 'perf-tools-fixes-for-v5.19-2022-07-17' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix SIGSEGV when processing syscall args in perf.data files in 'perf
   trace'

 - Sync kvm, msr-index and cpufeatures headers with the kernel sources

 - Fix 'convert perf time to TSC' 'perf test':
     - No need to open events twice
     - Fix finding correct event on hybrid systems

* tag 'perf-tools-fixes-for-v5.19-2022-07-17' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf trace: Fix SIGSEGV when processing syscall args
  perf tests: Fix Convert perf time to TSC test for hybrid
  perf tests: Stop Convert perf time to TSC test opening events twice
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  tools headers cpufeatures: Sync with the kernel sources
  tools headers UAPI: Sync linux/kvm.h with the kernel sources

Since segment_pages is no longer a compile time constant, it looks the
DIV_ROUND_UP(node->size, segment_pages) breaks the 32b build. Simplest
is just to use the ULL variant, but really we should need not need more
than u32 for the page alignment (also we are limited by that due to the
sg->length type), so also make it all u32.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: aff1e0b0 ("drm/i915/ttm: fix sg_table construction")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Nirmoy Das <nirmoy.das@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220712174050.592550-1-matthew.auld@intel.com
(cherry picked from commit 9306b2b2)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Pull perf fix from Borislav Petkov:

 - A single data race fix on the perf event cleanup path to avoid
   endless loops due to insufficient locking

* tag 'perf_urgent_for_v5.19_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()

Pull x86 fixes from Borislav Petkov:

 - Improve the check whether the kernel supports WP mappings so that it
   can accomodate a XenPV guest due to how the latter is setting up the
   PAT machinery

  - Now that the retbleed nightmare is public, here's the first round of
    fallout fixes:

      * Fix a build failure on 32-bit due to missing include

      * Remove an untraining point in espfix64 return path

      * other small cleanups

* tag 'x86_urgent_for_v5.19_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Remove apostrophe typo
  um: Add missing apply_returns()
  x86/entry: Remove UNTRAIN_RET from native_irq_return_ldt
  x86/bugs: Mark retbleed_strings static
  x86/pat: Fix x86_has_pat_wp()
  x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit

Pull gpio fix from Bartosz Golaszewski:

 - fix a configfs attribute of the gpio-sim module

* tag 'gpio-fixes-for-v5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: sim: fix the chip_name configfs item

Pull input fixes from Dmitry Torokhov:

 - fix Goodix driver to properly behave on the Aya Neo Next

 - some more sanity checks in usbtouchscreen driver

 - a tweak in wm97xx driver in preparation for remove() to return void

 - a clarification in input core regarding units of measurement for
   resolution on touch events.

* tag 'input-for-v5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: document the units for resolution of size axes
  Input: goodix - call acpi_device_fix_up_power() in some cases
  Input: wm97xx - make .remove() obviously always return 0
  Input: usbtouchscreen - add driver_info sanity check

Pull power supply fixes from Sebastian Reichel:

 - power-supply core temperature interpolation regression fix for
   incorrect boundaries

 - ab8500 needs to destroy its work queues in error paths

 - Fix old DT refcount leak in arm-versatile

* tag 'for-v5.19-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply:
  power: supply: core: Fix boundary conditions in interpolation
  power/reset: arm-versatile: Fix refcount leak in versatile_reboot_probe
  power: supply: ab8500_fg: add missing destroy_workqueue in ab8500_fg_probe

On powerpc, 'perf trace' is crashing with a SIGSEGV when trying to
process a perf.data file created with 'perf trace record -p':

  #0  0x00000001225b8988 in syscall_arg__scnprintf_augmented_string <snip> at builtin-trace.c:1492
  #1  syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1492
  #2  syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1486
  #3  0x00000001225bdd9c in syscall_arg_fmt__scnprintf_val <snip> at builtin-trace.c:1973
  #4  syscall__scnprintf_args <snip> at builtin-trace.c:2041
  #5  0x00000001225bff04 in trace__sys_enter <snip> at builtin-trace.c:2319

That points to the below code in tools/perf/builtin-trace.c:
	/*
	 * If this is raw_syscalls.sys_enter, then it always comes with the 6 possible
	 * arguments, even if the syscall being handled, say "openat", uses only 4 arguments
	 * this breaks syscall__augmented_args() check for augmented args, as we calculate
	 * syscall->args_size using each syscalls:sys_enter_NAME tracefs format file,
	 * so when handling, say the openat syscall, we end up getting 6 args for the
	 * raw_syscalls:sys_enter event, when we expected just 4, we end up mistakenly
	 * thinking that the extra 2 u64 args are the augmented filename, so just check
	 * here and avoid using augmented syscalls when the evsel is the raw_syscalls one.
	 */
	if (evsel != trace->syscalls.events.sys_enter)
		augmented_args = syscall__augmented_args(sc, sample, &augmented_args_size, trace->raw_augmented_syscalls_args_size);

As the comment points out, we should not be trying to augment the args
for raw_syscalls. However, when processing a perf.data file, we are not
initializing those properly. Fix the same.
Reported-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20220707090900.572584-1-naveen.n.rao@linux.vnet.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The test does not always correctly determine the number of events for
hybrids, nor allow for more than 1 evsel when parsing.

Fix by iterating the events actually created and getting the correct
evsel for the events processed.

Fixes: d9da6f70 ("perf tests: Support 'Convert perf time to TSC' test for hybrid")
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713123459.24145-3-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Do not call evlist__open() twice.

Fixes: 5bb017d4 ("perf test: Fix error message for test case 71 on s390, where it is not supported")
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713123459.24145-2-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes from these csets:

  4ad3278d ("x86/speculation: Disable RRSBA behavior")
  d7caac99 ("x86/cpu/amd: Add Spectral Chicken")

That cause no changes to tooling:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
  $ diff -u before after
  $

Just silences this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/YtQTm9wsB3hxQWvy@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes from:

  f43b9876 ("x86/retbleed: Add fine grained Kconfig knobs")
  a149180f ("x86: Add magic AMD return-thunk")
  15e67227 ("x86: Undo return-thunk damage")
  369ae6ff ("x86/retpoline: Cleanup some #ifdefery")
  4ad3278d x86/speculation: Disable RRSBA behavior
  26aae8cc x86/cpu/amd: Enumerate BTC_NO
  9756bba2 x86/speculation: Fill RSB on vmexit for IBRS
  3ebc1700 x86/bugs: Add retbleed=ibpb
  2dbb887e x86/entry: Add kernel IBRS implementation
  6b80b59b x86/bugs: Report AMD retbleed vulnerability
  a149180f x86: Add magic AMD return-thunk
  15e67227 x86: Undo return-thunk damage
  a883d624 x86/cpufeatures: Move RETPOLINE flags to word 11
  51802186 x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h'
  diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org
Link: https://lore.kernel.org/lkml/YtQM40VmiLTkPND2@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes in:

  1b870fa5 ("kvm: stats: tell userspace which values are boolean")

That just rebuilds perf, as these patches don't add any new KVM ioctl to
be harvested for the the 'perf trace' ioctl syscall argument
beautifiers.

This is also by now used by tools/testing/selftests/kvm/, a simple test
build succeeded.

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lore.kernel.org/lkml/YtQLDvQrBhJNl3n5@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>