Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "A comparatively quieter cycle for nfsd this time, but still with two
  larger changes:

   - RPC server scalability improvements from Jeff Layton (using RCU
     instead of a spinlock to find idle threads).

   - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna
     Schumaker, enabling fallocate on new clients"

* 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd4: fix xdr4 count of server in fs_location4
  nfsd4: fix xdr4 inclusion of escaped char
  sunrpc/cache: convert to use string_escape_str()
  sunrpc: only call test_bit once in svc_xprt_received
  fs: nfsd: Fix signedness bug in compare_blob
  sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt
  sunrpc: convert to lockless lookup of queued server threads
  sunrpc: fix potential races in pool_stats collection
  sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it
  sunrpc: require svc_create callers to pass in meaningful shutdown routine
  sunrpc: have svc_wake_up only deal with pool 0
  sunrpc: convert sp_task_pending flag to use atomic bitops
  sunrpc: move rq_cachetype field to better optimize space
  sunrpc: move rq_splice_ok flag into rq_flags
  sunrpc: move rq_dropme flag into rq_flags
  sunrpc: move rq_usedeferral flag to rq_flags
  sunrpc: move rq_local field to rq_flags
  sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it
  nfsd: minor off by one checks in __write_versions()
  sunrpc: release svc_pool_map reference when serv allocation fails
  ...

1 files changed, 37 insertions, 31 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4e1d7268b004..3550a9c87616 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -275,9 +275,11 @@ opaque_hashval(const void *ptr, int nbytes)
 	return x;
 }
 
-static void nfsd4_free_file(struct nfs4_file *f)
+static void nfsd4_free_file_rcu(struct rcu_head *rcu)
 {
-	kmem_cache_free(file_slab, f);
+	struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu);
+
+	kmem_cache_free(file_slab, fp);
 }
 
 static inline void
@@ -286,9 +288,10 @@ put_nfs4_file(struct nfs4_file *fi)
 	might_lock(&state_lock);
 
 	if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) {
-		hlist_del(&fi->fi_hash);
+		hlist_del_rcu(&fi->fi_hash);
 		spin_unlock(&state_lock);
-		nfsd4_free_file(fi);
+		WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
+		call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu);
 	}
 }
 
@@ -1440,7 +1443,7 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru
 	list_add(&new->se_perclnt, &clp->cl_sessions);
 	spin_unlock(&clp->cl_lock);
 
-	if (cses->flags & SESSION4_BACK_CHAN) {
+	{
 		struct sockaddr *sa = svc_addr(rqstp);
 		/*
 		 * This is a little silly; with sessions there's no real
@@ -1711,15 +1714,14 @@ static int copy_cred(struct svc_cred *target, struct svc_cred *source)
 	return 0;
 }
 
-static long long
+static int
 compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
 {
-	long long res;
-
-	res = o1->len - o2->len;
-	if (res)
-		return res;
-	return (long long)memcmp(o1->data, o2->data, o1->len);
+	if (o1->len < o2->len)
+		return -1;
+	if (o1->len > o2->len)
+		return 1;
+	return memcmp(o1->data, o2->data, o1->len);
 }
 
 static int same_name(const char *n1, const char *n2)
@@ -1907,7 +1909,7 @@ add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
 static struct nfs4_client *
 find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
 {
-	long long cmp;
+	int cmp;
 	struct rb_node *node = root->rb_node;
 	struct nfs4_client *clp;
 
@@ -3057,10 +3059,9 @@ static struct nfs4_file *nfsd4_alloc_file(void)
 }
 
 /* OPEN Share state helper functions */
-static void nfsd4_init_file(struct nfs4_file *fp, struct knfsd_fh *fh)
+static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
+				struct nfs4_file *fp)
 {
-	unsigned int hashval = file_hashval(fh);
-
 	lockdep_assert_held(&state_lock);
 
 	atomic_set(&fp->fi_ref, 1);
@@ -3073,7 +3074,7 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct knfsd_fh *fh)
 	fp->fi_share_deny = 0;
 	memset(fp->fi_fds, 0, sizeof(fp->fi_fds));
 	memset(fp->fi_access, 0, sizeof(fp->fi_access));
-	hlist_add_head(&fp->fi_hash, &file_hashtbl[hashval]);
+	hlist_add_head_rcu(&fp->fi_hash, &file_hashtbl[hashval]);
 }
 
 void
@@ -3294,17 +3295,14 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
 
 /* search file_hashtbl[] for file */
 static struct nfs4_file *
-find_file_locked(struct knfsd_fh *fh)
+find_file_locked(struct knfsd_fh *fh, unsigned int hashval)
 {
-	unsigned int hashval = file_hashval(fh);
 	struct nfs4_file *fp;
 
-	lockdep_assert_held(&state_lock);
-
-	hlist_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
+	hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash) {
 		if (nfsd_fh_match(&fp->fi_fhandle, fh)) {
-			get_nfs4_file(fp);
-			return fp;
+			if (atomic_inc_not_zero(&fp->fi_ref))
+				return fp;
 		}
 	}
 	return NULL;
@@ -3314,10 +3312,11 @@ static struct nfs4_file *
 find_file(struct knfsd_fh *fh)
 {
 	struct nfs4_file *fp;
+	unsigned int hashval = file_hashval(fh);
 
-	spin_lock(&state_lock);
-	fp = find_file_locked(fh);
-	spin_unlock(&state_lock);
+	rcu_read_lock();
+	fp = find_file_locked(fh, hashval);
+	rcu_read_unlock();
 	return fp;
 }
 
@@ -3325,11 +3324,18 @@ static struct nfs4_file *
 find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh)
 {
 	struct nfs4_file *fp;
+	unsigned int hashval = file_hashval(fh);
+
+	rcu_read_lock();
+	fp = find_file_locked(fh, hashval);
+	rcu_read_unlock();
+	if (fp)
+		return fp;
 
 	spin_lock(&state_lock);
-	fp = find_file_locked(fh);
-	if (fp == NULL) {
-		nfsd4_init_file(new, fh);
+	fp = find_file_locked(fh, hashval);
+	if (likely(fp == NULL)) {
+		nfsd4_init_file(fh, hashval, new);
 		fp = new;
 	}
 	spin_unlock(&state_lock);
@@ -4127,7 +4133,7 @@ void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
 		nfs4_put_stateowner(so);
 	}
 	if (open->op_file)
-		nfsd4_free_file(open->op_file);
+		kmem_cache_free(file_slab, open->op_file);
 	if (open->op_stp)
 		nfs4_put_stid(&open->op_stp->st_stid);
 }