On Mon, Feb 06 2017, Kinglong Mee wrote:
> When the first time pynfs runs after rpc/nfsd startup, always get the warning,
>
> "Got error: Connection closed"
>
> I found the problem is caused by,
> 1. A new startup of nfsd, rpc.mountd, etc,
> 2. A rpc request from client (pynfs test, or normal mounting),
> 3. An ip_map cache is created but invalid, so upcall to rpc.mountd,
> 4. rpc.mountd process the ip_map upcall, before write the valid data to nfsd,
> do auth_reload(), and check_useipaddr(),
> 5. For the first time, old_use_ipaddr = -1, it causes rpc.mountd do write_flush that doing cache_clean,
> 6. The ip_map cache will be treat as expired and clean,
> 7. When rpc.mountd write the valid data to nfsd, a new ip_map is created
> and updated, the cache_check of old ip_map(doing the upcall) will
> return -ETIMEDOUT.
> 8. RPC layer return SVC_CLOSE and close the xprt after commit 4d712ef1db05
> "svcauth_gss: Close connection when dropping an incoming message"
>
> NeilBrown suggest in another email,
>
> "If CACHE_VALID is not set, then there is no data in the cache item,
> so there is nothing to expire. So it would be nice if cache items that
> don't have CACHE_VALID are never treated as expired."
>
> v2, change the checking of CACHE_PENDING to CACHE_VALID
>
> Signed-off-by: Kinglong Mee <kinglongmee@xxxxxxxxx>
> ---
> include/linux/sunrpc/cache.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
> index 62a60ee..782024e 100644
> --- a/include/linux/sunrpc/cache.h
> +++ b/include/linux/sunrpc/cache.h
> @@ -204,8 +204,11 @@ static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
> kref_put(&h->ref, cd->cache_put);
> }
>
> -static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
> +static inline bool cache_is_expired(struct cache_detail *detail, struct cache_head *h)
> {
> + if (!test_bit(CACHE_VALID, &h->flags))
> + return false;
> +
> return (h->expiry_time < seconds_since_boot()) ||
> (detail->flush_time >= h->last_refresh);
> }
> --
> 2.9.3
Thanks for this.
I think it would be best if this patch were applied *after* the change
to cache_purge(), to avoid possible issues if a git-bisect lands between
these two.
Apart from that:\
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Thanks,
NeilBrown
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