Merge tag 'nfs-for-4.7-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Highlights include:

  Features:
   - Add support for the NFS v4.2 COPY operation
   - Add support for NFS/RDMA over IPv6

  Bugfixes and cleanups:
   - Avoid race that crashes nfs_init_commit()
   - Fix oops in callback path
   - Fix LOCK/OPEN race when unlinking an open file
   - Choose correct stateids when using delegations in setattr, read and
     write
   - Don't send empty SETATTR after OPEN_CREATE
   - xprtrdma: Prevent server from writing a reply into memory client
     has released
   - xprtrdma: Support using Read list and Reply chunk in one RPC call"

* tag 'nfs-for-4.7-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (61 commits)
  pnfs: pnfs_update_layout needs to consider if strict iomode checking is on
  nfs/flexfiles: Use the layout segment for reading unless it a IOMODE_RW and reading is disabled
  nfs/flexfiles: Helper function to detect FF_FLAGS_NO_READ_IO
  nfs: avoid race that crashes nfs_init_commit
  NFS: checking for NULL instead of IS_ERR() in nfs_commit_file()
  pnfs: make pnfs_layout_process more robust
  pnfs: rework LAYOUTGET retry handling
  pnfs: lift retry logic from send_layoutget to pnfs_update_layout
  pnfs: fix bad error handling in send_layoutget
  flexfiles: add kerneldoc header to nfs4_ff_layout_prepare_ds
  flexfiles: remove pointless setting of NFS_LAYOUT_RETURN_REQUESTED
  pnfs: only tear down lsegs that precede seqid in LAYOUTRETURN args
  pnfs: keep track of the return sequence number in pnfs_layout_hdr
  pnfs: record sequence in pnfs_layout_segment when it's created
  pnfs: don't merge new ff lsegs with ones that have LAYOUTRETURN bit set
  pNFS/flexfiles: When initing reads or writes, we might have to retry connecting to DSes
  pNFS/flexfiles: When checking for available DSes, conditionally check for MDS io
  pNFS/flexfile: Fix erroneous fall back to read/write through the MDS
  NFS: Reclaim writes via writepage are opportunistic
  NFSv4: Use the right stateid for delegations in setattr, read and write
  ...

1 files changed, 23 insertions, 3 deletions

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 6a241a277249..899791573a40 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -127,7 +127,7 @@ struct rpc_authops {
 	void			(*destroy)(struct rpc_auth *);
 
 	struct rpc_cred *	(*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
-	struct rpc_cred *	(*crcreate)(struct rpc_auth*, struct auth_cred *, int);
+	struct rpc_cred *	(*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t);
 	int			(*list_pseudoflavors)(rpc_authflavor_t *, int);
 	rpc_authflavor_t	(*info2flavor)(struct rpcsec_gss_info *);
 	int			(*flavor2info)(rpc_authflavor_t,
@@ -167,6 +167,7 @@ void 			rpc_destroy_authunix(void);
 
 struct rpc_cred *	rpc_lookup_cred(void);
 struct rpc_cred *	rpc_lookup_cred_nonblock(void);
+struct rpc_cred *	rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t);
 struct rpc_cred *	rpc_lookup_machine_cred(const char *service_name);
 int			rpcauth_register(const struct rpc_authops *);
 int			rpcauth_unregister(const struct rpc_authops *);
@@ -178,7 +179,7 @@ rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
 int			rpcauth_get_gssinfo(rpc_authflavor_t,
 				struct rpcsec_gss_info *);
 int			rpcauth_list_flavors(rpc_authflavor_t *, int);
-struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int);
+struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t);
 void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
 struct rpc_cred *	rpcauth_lookupcred(struct rpc_auth *, int);
 struct rpc_cred *	rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int);
@@ -201,9 +202,28 @@ char *			rpcauth_stringify_acceptor(struct rpc_cred *);
 static inline
 struct rpc_cred *	get_rpccred(struct rpc_cred *cred)
 {
-	atomic_inc(&cred->cr_count);
+	if (cred != NULL)
+		atomic_inc(&cred->cr_count);
 	return cred;
 }
 
+/**
+ * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer
+ * @cred: cred of which to take a reference
+ *
+ * In some cases, we may have a pointer to a credential to which we
+ * want to take a reference, but don't already have one. Because these
+ * objects are freed using RCU, we can access the cr_count while its
+ * on its way to destruction and only take a reference if it's not already
+ * zero.
+ */
+static inline struct rpc_cred *
+get_rpccred_rcu(struct rpc_cred *cred)
+{
+	if (atomic_inc_not_zero(&cred->cr_count))
+		return cred;
+	return NULL;
+}
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SUNRPC_AUTH_H */