linux.git/include/linux/sunrpc/cache.h, branch v7.1-rc3

sunrpc: split cache_detail queue into request and reader lists

2026-03-30T01:25:09+00:00

Replace the single interleaved queue (which mixed cache_request and
cache_reader entries distinguished by a ->reader flag) with two
dedicated lists: cd->requests for upcall requests and cd->readers
for open file handles.

Readers now track their position via a monotonically increasing
sequence number (next_seqno) rather than by their position in the
shared list. Each cache_request is assigned a seqno when enqueued,
and a new cache_next_request() helper finds the next request at or
after a given seqno.

This eliminates the cache_queue wrapper struct entirely, simplifies
the reader-skipping loops in cache_read/cache_poll/cache_ioctl/
cache_release, and makes the data flow easier to reason about.

Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever

sunrpc: convert queue_wait from global to per-cache-detail waitqueue

2026-03-30T01:25:09+00:00

The queue_wait waitqueue is currently a file-scoped global, so a
wake_up for one cache_detail wakes pollers on all caches. Convert it
to a per-cache-detail field so that only pollers on the relevant cache
are woken.

Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever

sunrpc: convert queue_lock from global spinlock to per-cache-detail lock

2026-03-30T01:25:09+00:00

The global queue_lock serializes all upcall queue operations across
every cache_detail instance. Convert it to a per-cache-detail spinlock
so that different caches (e.g. auth.unix.ip vs nfsd.fh) no longer
contend with each other on queue operations.

Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever

SUNRPC: introduce cache_check_rcu to help check in rcu context

2025-01-06T14:37:40+00:00

This is a prepare patch to add cache_check_rcu, will use it with follow
patch.

Suggested-by: NeilBrown 
Signed-off-by: Yang Erkun 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

SUNRPC: change cache_head.flags bits to enum

2023-08-29T21:45:22+00:00

When a sequence of numbers are needed for internal-use only, an enum is
typically best.  The sequence will inevitably need to be changed one
day, and having an enum means the developer doesn't need to think about
renumbering after insertion or deletion.  Such patches will be easier
to review.

Signed-off-by: NeilBrown 
Signed-off-by: Chuck Lever

SUNRPC: return proper error from get_expiry()

2023-04-26T13:05:00+00:00

The get_expiry() function currently returns a timestamp, and uses the
special return value of 0 to indicate an error.

Unfortunately this causes a problem when 0 is the correct return value.

On a system with no RTC it is possible that the boot time will be seen
to be "3".  When exportfs probes to see if a particular filesystem
supports NFS export it tries to cache information with an expiry time of
"3".  The intention is for this to be "long in the past".  Even with no
RTC it will not be far in the future (at most a second or two) so this
is harmless.
But if the boot time happens to have been calculated to be "3", then
get_expiry will fail incorrectly as it converts the number to "seconds
since bootime" - 0.

To avoid this problem we change get_expiry() to report the error quite
separately from the expiry time.  The error is now the return value.
The expiry time is reported through a by-reference parameter.

Reported-by: Jerry Zhang 
Tested-by: Jerry Zhang 
Signed-off-by: NeilBrown 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

SUNRPC: Make cache_req::thread_wait an unsigned long

2022-05-19T16:25:39+00:00

The second parameter of wait_for_completion_interruptible_timeout()
is a jiffies value whose type is "unsigned long". Avoid an
unnecessary and potentially fraught implicit type conversion at the
wait_for_completion_interruptible_timeout() call site in
cache_wait_req().

Signed-off-by: Chuck Lever

kernel.h: split out kstrtox() and simple_strtox() to a separate header

2021-07-01T18:06:05+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out kstrtox() and
simple_strtox() helpers.

At the same time convert users in header and lib folders to use new
header.  Though for time being include new header back to kernel.h to
avoid twisted indirected includes for existing users.

[andy.shevchenko@gmail.com: fix documentation references]
  Link: https://lkml.kernel.org/r/20210615220003.377901-1-andy.shevchenko@gmail.com

Link: https://lkml.kernel.org/r/20210611185815.44103-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Acked-by: Jonathan Cameron 
Cc: Francis Laniel 
Cc: Randy Dunlap 
Cc: Kars Mulder 
Cc: Trond Myklebust 
Cc: Anna Schumaker 
Cc: "J. Bruce Fields" 
Cc: Chuck Lever 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sunrpc: fix duplicated word in

2020-09-21T14:21:10+00:00

Change "time time" to "time expiry_time" to match the field name.

Signed-off-by: Randy Dunlap 
Cc: "J. Bruce Fields" 
Cc: Chuck Lever 
Cc: Trond Myklebust 
Cc: Anna Schumaker 
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Anna Schumaker

SUNRPC/cache: don't allow invalid entries to be flushed

2020-03-27T16:17:31+00:00

Trond points out in commit 277f27e2f277 ("SUNRPC/cache: Allow
garbage collection of invalid cache entries") that we allow invalid
cache entries to persist indefinitely. That fix, however,
reintroduces the problem fixed by Kinglong Mee's commit d6fc8821c2d2
("SUNRPC/Cache: Always treat the invalid cache as unexpired"), where
an invalid cache entry is immediately removed by a flush before
mountd responds to it. The result is that the server thread that
should be waiting for mountd to fill in that entry instead gets an
-ETIMEDOUT return from cache_check(). Symptoms are the server
becoming unresponsive after a restart, reproduceable by running
pynfs 4.1 test REBT5.

Instead, take a compromise approach: allow invalid cache entries to
be removed after they expire, but not to be removed by a cache
flush.

Fixes: 277f27e2f277 ("SUNRPC/cache: Allow garbage collection ... ")
Signed-off-by: J. Bruce Fields 
Signed-off-by: Chuck Lever