Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux

Pull nfsd changes from J Bruce Fields:
 "Miscellaneous bugfixes, plus:

   - An overhaul of the DRC cache by Jeff Layton.  The main effect is
     just to make it larger.  This decreases the chances of intermittent
     errors especially in the UDP case.  But we'll need to watch for any
     reports of performance regressions.

   - Containerized nfsd: with some limitations, we now support
     per-container nfs-service, thanks to extensive work from Stanislav
     Kinsbursky over the last year."

Some notes about conflicts, since there were *two* non-data semantic
conflicts here:

 - idr_remove_all() had been added by a memory leak fix, but has since
   become deprecated since idr_destroy() does it for us now.

 - xs_local_connect() had been added by this branch to make AF_LOCAL
   connections be synchronous, but in the meantime Trond had changed the
   calling convention in order to avoid a RCU dereference.

There were a couple of more obvious actual source-level conflicts due to
the hlist traversal changes and one just due to code changes next to
each other, but those were trivial.

* 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits)
  SUNRPC: make AF_LOCAL connect synchronous
  nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum
  svcrpc: fix rpc server shutdown races
  svcrpc: make svc_age_temp_xprts enqueue under sv_lock
  lockd: nlmclnt_reclaim(): avoid stack overflow
  nfsd: enable NFSv4 state in containers
  nfsd: disable usermode helper client tracker in container
  nfsd: use proper net while reading "exports" file
  nfsd: containerize NFSd filesystem
  nfsd: fix comments on nfsd_cache_lookup
  SUNRPC: move cache_detail->cache_request callback call to cache_read()
  SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function
  SUNRPC: rework cache upcall logic
  SUNRPC: introduce cache_detail->cache_request callback
  NFS: simplify and clean cache library
  NFS: use SUNRPC cache creation and destruction helper for DNS cache
  nfsd4: free_stid can be static
  nfsd: keep a checksum of the first 256 bytes of request
  sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
  sunrpc: fix comment in struct xdr_buf definition
  ...

1 files changed, 29 insertions, 22 deletions

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 39a4112faf54..25d58e766014 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -196,9 +196,9 @@ EXPORT_SYMBOL_GPL(sunrpc_cache_update);
 
 static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
 {
-        if (!cd->cache_upcall)
-                return -EINVAL;
-        return cd->cache_upcall(cd, h);
+        if (cd->cache_upcall)
+                return cd->cache_upcall(cd, h);
+        return sunrpc_cache_pipe_upcall(cd, h);
 }
 
 static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h)
@@ -750,6 +750,18 @@ struct cache_reader {
         int                     offset; /* if non-0, we have a refcnt on next request */
 };
 
+static int cache_request(struct cache_detail *detail,
+                               struct cache_request *crq)
+{
+        char *bp = crq->buf;
+        int len = PAGE_SIZE;
+
+        detail->cache_request(detail, crq->item, &bp, &len);
+        if (len < 0)
+                return -EAGAIN;
+        return PAGE_SIZE - len;
+}
+
 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
                           loff_t *ppos, struct cache_detail *cd)
 {
@@ -784,6 +796,13 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
                 rq->readers++;
         spin_unlock(&queue_lock);
 
+        if (rq->len == 0) {
+                err = cache_request(cd, rq);
+                if (err < 0)
+                        goto out;
+                rq->len = err;
+        }
+
         if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
                 err = -EAGAIN;
                 spin_lock(&queue_lock);
@@ -1140,17 +1159,14 @@ static bool cache_listeners_exist(struct cache_detail *detail)
  *
  * Each request is at most one page long.
  */
-int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
-                void (*cache_request)(struct cache_detail *,
-                                      struct cache_head *,
-                                      char **,
-                                      int *))
+int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
 {
 
         char *buf;
         struct cache_request *crq;
-        char *bp;
-        int len;
+
+        if (!detail->cache_request)
+                return -EINVAL;
 
         if (!cache_listeners_exist(detail)) {
                 warn_no_listener(detail);
@@ -1167,19 +1183,10 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
                 return -EAGAIN;
         }
 
-        bp = buf; len = PAGE_SIZE;
-
-        cache_request(detail, h, &bp, &len);
-
-        if (len < 0) {
-                kfree(buf);
-                kfree(crq);
-                return -EAGAIN;
-        }
         crq->q.reader = 0;
         crq->item = cache_get(h);
         crq->buf = buf;
-        crq->len = PAGE_SIZE - len;
+        crq->len = 0;
         crq->readers = 0;
         spin_lock(&queue_lock);
         list_add_tail(&crq->q.list, &detail->queue);
@@ -1605,7 +1612,7 @@ static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
         if (p == NULL)
                 goto out_nomem;
 
-        if (cd->cache_upcall || cd->cache_parse) {
+        if (cd->cache_request || cd->cache_parse) {
                 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
                                      cd->u.procfs.proc_ent,
                                      &cache_file_operations_procfs, cd);
@@ -1614,7 +1621,7 @@ static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
                         goto out_nomem;
         }
         if (cd->cache_show) {
-                p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
+                p = proc_create_data("content", S_IFREG|S_IRUSR,
                                 cd->u.procfs.proc_ent,
                                 &content_file_operations_procfs, cd);
                 cd->u.procfs.content_ent = p;