On Thu, Aug 12, 2010 at 05:04:06PM +1000, NeilBrown wrote:
> The idmap code manages request deferal by waiting for a reply from
> userspace rather than putting the NFS request on a queue to be retried
> from the start.
> Now that the common deferal code does this there is no need for the
> special code in idmap.
Applied (with minor fixup to get it to apply after seconds-since-boot
change).
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
> fs/nfsd/nfs4idmap.c | 105 +++++----------------------------------------------
> 1 files changed, 11 insertions(+), 94 deletions(-)
And yay for that diffstat....
--b.
>
> diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
> index c78dbf4..f0695e8 100644
> --- a/fs/nfsd/nfs4idmap.c
> +++ b/fs/nfsd/nfs4idmap.c
> @@ -482,109 +482,26 @@ nfsd_idmap_shutdown(void)
> cache_unregister(&nametoid_cache);
> }
>
> -/*
> - * Deferred request handling
> - */
> -
> -struct idmap_defer_req {
> - struct cache_req req;
> - struct cache_deferred_req deferred_req;
> - wait_queue_head_t waitq;
> - atomic_t count;
> -};
> -
> -static inline void
> -put_mdr(struct idmap_defer_req *mdr)
> -{
> - if (atomic_dec_and_test(&mdr->count))
> - kfree(mdr);
> -}
> -
> -static inline void
> -get_mdr(struct idmap_defer_req *mdr)
> -{
> - atomic_inc(&mdr->count);
> -}
> -
> -static void
> -idmap_revisit(struct cache_deferred_req *dreq, int toomany)
> -{
> - struct idmap_defer_req *mdr =
> - container_of(dreq, struct idmap_defer_req, deferred_req);
> -
> - wake_up(&mdr->waitq);
> - put_mdr(mdr);
> -}
> -
> -static struct cache_deferred_req *
> -idmap_defer(struct cache_req *req)
> -{
> - struct idmap_defer_req *mdr =
> - container_of(req, struct idmap_defer_req, req);
> -
> - mdr->deferred_req.revisit = idmap_revisit;
> - get_mdr(mdr);
> - return (&mdr->deferred_req);
> -}
> -
> -static inline int
> -do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
> - struct cache_detail *detail, struct ent **item,
> - struct idmap_defer_req *mdr)
> -{
> - *item = lookup_fn(key);
> - if (!*item)
> - return -ENOMEM;
> - return cache_check(detail, &(*item)->h, &mdr->req);
> -}
> -
> -static inline int
> -do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
> - struct ent *key, struct cache_detail *detail,
> - struct ent **item)
> -{
> - int ret = -ENOMEM;
> -
> - *item = lookup_fn(key);
> - if (!*item)
> - goto out_err;
> - ret = -ETIMEDOUT;
> - if (!test_bit(CACHE_VALID, &(*item)->h.flags)
> - || (*item)->h.expiry_time < get_seconds()
> - || detail->flush_time > (*item)->h.last_refresh)
> - goto out_put;
> - ret = -ENOENT;
> - if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
> - goto out_put;
> - return 0;
> -out_put:
> - cache_put(&(*item)->h, detail);
> -out_err:
> - *item = NULL;
> - return ret;
> -}
> -
> static int
> idmap_lookup(struct svc_rqst *rqstp,
> struct ent *(*lookup_fn)(struct ent *), struct ent *key,
> struct cache_detail *detail, struct ent **item)
> {
> - struct idmap_defer_req *mdr;
> int ret;
>
> - mdr = kzalloc(sizeof(*mdr), GFP_KERNEL);
> - if (!mdr)
> + *item = lookup_fn(key);
> + if (!*item)
> return -ENOMEM;
> - atomic_set(&mdr->count, 1);
> - init_waitqueue_head(&mdr->waitq);
> - mdr->req.defer = idmap_defer;
> - ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
> - if (ret == -EAGAIN) {
> - wait_event_interruptible_timeout(mdr->waitq,
> - test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
> - ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
> + retry:
> + ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
> +
> + if (ret == -ETIMEDOUT) {
> + struct ent *prev_item = *item;
> + *item = lookup_fn(key);
> + if (*item != prev_item)
> + goto retry;
> + cache_put(&(*item)->h, detail);
> }
> - put_mdr(mdr);
> return ret;
> }
>
>
>
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