kernel/linux.git/include/linux/sunrpc/cache.h, branch v6.6.132

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

SUNRPC/cache: Allow garbage collection of invalid cache entries

2020-03-16T16:04:34+00:00

If the cache entry never gets initialised, we want the garbage collector to be able to evict it. Otherwise if the upcall daemon fails to initialise the entry, we end up never expiring it. Signed-off-by: Trond Myklebust [ cel: resolved a merge conflict ] Signed-off-by: Chuck Lever

nfsd: export upcalls must not return ESTALE when mountd is down

2020-03-16T16:04:33+00:00

If the rpc.mountd daemon goes down, then that should not cause all exports to start failing with ESTALE errors. Let's explicitly distinguish between the cache upcall cases that need to time out, and those that do not. Signed-off-by: Trond Myklebust Signed-off-by: Chuck Lever

nfs: use time64_t internally

2019-12-18T17:07:32+00:00

The timestamps for the cache are all in boottime seconds, so they don't overflow 32-bit values, but the use of time_t is deprecated because it generally does overflow when used with wall-clock time. There are multiple possible ways of avoiding it: - leave time_t, which is safe here, but forces others to look into this code to determine that it is over and over. - use a more generic type, like 'int' or 'long', which is known to be sufficient here but loses the documentation of referring to timestamps - use ktime_t everywhere, and convert into seconds in the few places where we want realtime-seconds. The conversion is sometimes expensive, but not more so than the conversion we do today. - use time64_t to clarify that this code is safe. Nothing would change for 64-bit architectures, but it is slightly less efficient on 32-bit architectures. Without a clear winner of the three approaches above, this picks the last one, favouring readability over a small performance loss on 32-bit architectures. Signed-off-by: Arnd Bergmann

sunrpc: add a new cache_detail operation for when a cache is flushed

2019-08-19T15:00:39+00:00

When the exports table is changed, exportfs will usually write a new time to the "flush" file in the nfsd.export cache procfile. This tells the kernel to flush any entries that are older than that value. This gives us a mechanism to tell whether an unexport might have occurred. Add a new ->flush cache_detail operation that is called after flushing the cache whenever someone writes to a "flush" file. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields