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Commit 839049a8 authored by NeilBrown's avatar NeilBrown Committed by J. Bruce Fields
Browse files

nfsd/idmap: drop special request deferal in favour of improved default. 



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.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 8ff30fa4

fs/nfsd/nfs4idmap.c

+11 −94
Original line number Diff line number Diff line
@@ -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)

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 =

		container_of(req, struct idmap_defer_req, req);



	mdr->deferred_req.revisit = idmap_revisit;

	get_mdr(mdr);

	return (&mdr->deferred_req);

}

	int ret;



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;

 retry:

	ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);



	if (ret == -ETIMEDOUT) {

		struct ent *prev_item = *item;

		*item = lookup_fn(key);

	if (!*item)

		goto out_err;

	ret = -ETIMEDOUT;

	if (!test_bit(CACHE_VALID, &(*item)->h.flags)

			|| (*item)->h.expiry_time < seconds_since_boot()

			|| 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:

		if (*item != prev_item)

			goto retry;

		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)

		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);

	}

	put_mdr(mdr);

	return ret;

}