[PATCH 09/12] nfsd/idmap: drop special request deferal in favour of improved default.

NeilBrown
2009-08-04T05:25:12Z

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 comment deferal code does this there is no need for the
special code in idmap.

Signed-off-by: NeilBrown <neilb@suse.de>
---

fs/nfsd/nfs4idmap.c | 105 +++++----------------------------------------------
1 files changed, 11 insertions(+), 94 deletions(-)

diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 5b39842..d6d37f8 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -485,109 +485,26 @@ 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;
}