Thanks! Applying for 3.6--b.
On Thu, Jul 12, 2012 at 10:37:34AM +1000, NeilBrown wrote:
>
> Entries that are in a sunrpc cache but are not valid should be reported
> with a leading '#' so they look like a comment.
> Commit d202cce8963d9 (sunrpc: never return expired entries in sunrpc_cache_lookup)
> broke this for expired entries.
>
> This particularly applies to entries that have been replaced by newer entries.
> sunrpc_cache_update sets the expiry of the replaced entry to '0', but it
> remains in the cache until the next 'cache_clean'.
> The result is that if you
>
> echo 0 2000000000 1 0 > /proc/net/rpc/auth.unix.gid/channel
>
> several times, then
>
> cat /proc/net/rpc/auth.unix.gid/content
>
> It will display multiple entries for the one uid, which is at least confusing:
>
> #uid cnt: gids...
> 0 1: 0
> 0 1: 0
> 0 1: 0
>
> With this patch, expired entries are marked as comments so you get
>
> #uid cnt: gids...
> 0 1: 0
> # 0 1: 0
> # 0 1: 0
>
> These expired entries will never be seen by cache_check() as they are always
> *after* a non-expired entry with the same key - so the extra check is only
> needed in c_show()
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
>
> --
> It's not a big problem, but it had me confused for a while, so it could
> well confuse others.
> Thanks,
> NeilBrown
>
>
>
> diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
> index 47ad266..2afd2a8 100644
> --- a/net/sunrpc/cache.c
> +++ b/net/sunrpc/cache.c
> @@ -1349,8 +1349,11 @@ static int c_show(struct seq_file *m, void *p)
> if (cache_check(cd, cp, NULL))
> /* cache_check does a cache_put on failure */
> seq_printf(m, "# ");
> - else
> + else {
> + if (cache_is_expired(cd, cp))
> + seq_printf(m, "# ");
> cache_put(cp, cd);
> + }
>
> return cd->cache_show(m, cd, cp);
> }
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