Merge branch 'for-3.10' of git://linux-nfs.org/~bfields/linux

Pull nfsd changes from J Bruce Fields:
 "Highlights include:

   - Some more DRC cleanup and performance work from Jeff Layton

   - A gss-proxy upcall from Simo Sorce: currently krb5 mounts to the
     server using credentials from Active Directory often fail due to
     limitations of the svcgssd upcall interface.  This replacement
     lifts those limitations.  The existing upcall is still supported
     for backwards compatibility.

   - More NFSv4.1 support: at this point, if a user with a current
     client who upgrades from 4.0 to 4.1 should see no regressions.  In
     theory we do everything a 4.1 server is required to do.  Patches
     for a couple minor exceptions are ready for 3.11, and with those
     and some more testing I'd like to turn 4.1 on by default in 3.11."

Fix up semantic conflict as per Stephen Rothwell and linux-next:

Commit 030d794 ("SUNRPC: Use gssproxy upcall for server RPCGSS
authentication") adds two new users of "PDE(inode)->data", but we're
supposed to use "PDE_DATA(inode)" instead since commit d9dda78
("procfs: new helper - PDE_DATA(inode)").

The old PDE() macro is no longer available since commit c30480b
("proc: Make the PROC_I() and PDE() macros internal to procfs")

* 'for-3.10' of git://linux-nfs.org/~bfields/linux: (60 commits)
  NFSD: SECINFO doesn't handle unsupported pseudoflavors correctly
  NFSD: Simplify GSS flavor encoding in nfsd4_do_encode_secinfo()
  nfsd: make symbol nfsd_reply_cache_shrinker static
  svcauth_gss: fix error return code in rsc_parse()
  nfsd4: don't remap EISDIR errors in rename
  svcrpc: fix gss-proxy to respect user namespaces
  SUNRPC: gssp_procedures[] can be static
  SUNRPC: define {create,destroy}_use_gss_proxy_proc_entry in !PROC case
  nfsd4: better error return to indicate SSV non-support
  nfsd: fix EXDEV checking in rename
  SUNRPC: Use gssproxy upcall for server RPCGSS authentication.
  SUNRPC: Add RPC based upcall mechanism for RPCGSS auth
  SUNRPC: conditionally return endtime from import_sec_context
  SUNRPC: allow disabling idle timeout
  SUNRPC: attempt AF_LOCAL connect on setup
  nfsd: Decode and send 64bit time values
  nfsd4: put_client_renew_locked can be static
  nfsd4: remove unused macro
  nfsd4: remove some useless code
  nfsd4: implement SEQ4_STATUS_RECALLABLE_STATE_REVOKED
  ...

Documentation/filesystems/nfs/00-INDEX

@@ -20,3 +20,5 @@ rpc-cache.txt
 	- introduction to the caching mechanisms in the sunrpc layer.
 idmapper.txt
 	- information for configuring request-keys to be used by idmapper
+knfsd-rpcgss.txt
+	- Information on GSS authentication support in the NFS Server

Documentation/filesystems/nfs/rpc-server-gss.txt

@@ -0,0 +1,91 @@
+
+rpcsec_gss support for kernel RPC servers
+=========================================
+
+This document gives references to the standards and protocols used to
+implement RPCGSS authentication in kernel RPC servers such as the NFS
+server and the NFS client's NFSv4.0 callback server.  (But note that
+NFSv4.1 and higher don't require the client to act as a server for the
+purposes of authentication.)
+
+RPCGSS is specified in a few IETF documents:
+ - RFC2203 v1: http://tools.ietf.org/rfc/rfc2203.txt
+ - RFC5403 v2: http://tools.ietf.org/rfc/rfc5403.txt
+and there is a 3rd version  being proposed:
+ - http://tools.ietf.org/id/draft-williams-rpcsecgssv3.txt
+   (At draft n. 02 at the time of writing)
+
+Background
+----------
+
+The RPCGSS Authentication method describes a way to perform GSSAPI
+Authentication for NFS.  Although GSSAPI is itself completely mechanism
+agnostic, in many cases only the KRB5 mechanism is supported by NFS
+implementations.
+
+The Linux kernel, at the moment, supports only the KRB5 mechanism, and
+depends on GSSAPI extensions that are KRB5 specific.
+
+GSSAPI is a complex library, and implementing it completely in kernel is
+unwarranted. However GSSAPI operations are fundementally separable in 2
+parts:
+- initial context establishment
+- integrity/privacy protection (signing and encrypting of individual
+  packets)
+
+The former is more complex and policy-independent, but less
+performance-sensitive.  The latter is simpler and needs to be very fast.
+
+Therefore, we perform per-packet integrity and privacy protection in the
+kernel, but leave the initial context establishment to userspace.  We
+need upcalls to request userspace to perform context establishment.
+
+NFS Server Legacy Upcall Mechanism
+----------------------------------
+
+The classic upcall mechanism uses a custom text based upcall mechanism
+to talk to a custom daemon called rpc.svcgssd that is provide by the
+nfs-utils package.
+
+This upcall mechanism has 2 limitations:
+
+A) It can handle tokens that are no bigger than 2KiB
+
+In some Kerberos deployment GSSAPI tokens can be quite big, up and
+beyond 64KiB in size due to various authorization extensions attacked to
+the Kerberos tickets, that needs to be sent through the GSS layer in
+order to perform context establishment.
+
+B) It does not properly handle creds where the user is member of more
+than a few housand groups (the current hard limit in the kernel is 65K
+groups) due to limitation on the size of the buffer that can be send
+back to the kernel (4KiB).
+
+NFS Server New RPC Upcall Mechanism
+-----------------------------------
+
+The newer upcall mechanism uses RPC over a unix socket to a daemon
+called gss-proxy, implemented by a userspace program called Gssproxy.
+
+The gss_proxy RPC protocol is currently documented here:
+
+	https://fedorahosted.org/gss-proxy/wiki/ProtocolDocumentation
+
+This upcall mechanism uses the kernel rpc client and connects to the gssproxy
+userspace program over a regular unix socket. The gssproxy protocol does not
+suffer from the size limitations of the legacy protocol.
+
+Negotiating Upcall Mechanisms
+-----------------------------
+
+To provide backward compatibility, the kernel defaults to using the
+legacy mechanism.  To switch to the new mechanism, gss-proxy must bind
+to /var/run/gssproxy.sock and then write "1" to
+/proc/net/rpc/use-gss-proxy.  If gss-proxy dies, it must repeat both
+steps.
+
+Once the upcall mechanism is chosen, it cannot be changed.  To prevent
+locking into the legacy mechanisms, the above steps must be performed
+before starting nfsd.  Whoever starts nfsd can guarantee this by reading
+from /proc/net/rpc/use-gss-proxy and checking that it contains a
+"1"--the read will block until gss-proxy has done its write to the file.

fs/nfsd/cache.h

@@ -82,6 +82,7 @@ int	nfsd_reply_cache_init(void);
 void	nfsd_reply_cache_shutdown(void);
 int	nfsd_cache_lookup(struct svc_rqst *);
 void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);
+int	nfsd_reply_cache_stats_open(struct inode *, struct file *);
 
 #ifdef CONFIG_NFSD_V4
 void	nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);

fs/nfsd/netns.h

@@ -80,6 +80,7 @@ struct nfsd_net {
 	 */
 	struct list_head client_lru;
 	struct list_head close_lru;
+	struct list_head del_recall_lru;
 
 	struct delayed_work laundromat_work;
 

fs/nfsd/nfs4callback.c

@@ -37,6 +37,7 @@
 #include "nfsd.h"
 #include "state.h"
 #include "netns.h"
+#include "xdr4cb.h"
 
 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 
@@ -53,30 +54,6 @@ enum {
 	NFSPROC4_CLNT_CB_SEQUENCE,
 };
 
-#define NFS4_MAXTAGLEN		20
-
-#define NFS4_enc_cb_null_sz		0
-#define NFS4_dec_cb_null_sz		0
-#define cb_compound_enc_hdr_sz		4
-#define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
-#define sessionid_sz			(NFS4_MAX_SESSIONID_LEN >> 2)
-#define cb_sequence_enc_sz		(sessionid_sz + 4 +             \
-					1 /* no referring calls list yet */)
-#define cb_sequence_dec_sz		(op_dec_sz + sessionid_sz + 4)
-
-#define op_enc_sz			1
-#define op_dec_sz			2
-#define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
-#define enc_stateid_sz			(NFS4_STATEID_SIZE >> 2)
-#define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
-					cb_sequence_enc_sz +            \
-					1 + enc_stateid_sz +            \
-					enc_nfs4_fh_sz)
-
-#define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
-					cb_sequence_dec_sz +            \
-					op_dec_sz)
-
 struct nfs4_cb_compound_hdr {
 	/* args */
 	u32		ident;	/* minorversion 0 only */
@@ -817,8 +794,7 @@ static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
 {
 	struct nfsd4_callback *cb = calldata;
-	struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
-	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	struct nfs4_client *clp = cb->cb_clp;
 	u32 minorversion = clp->cl_minorversion;
 
 	cb->cb_minorversion = minorversion;
@@ -839,8 +815,7 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
 {
 	struct nfsd4_callback *cb = calldata;
-	struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
-	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	struct nfs4_client *clp = cb->cb_clp;
 
 	dprintk("%s: minorversion=%d\n", __func__,
 		clp->cl_minorversion);
@@ -863,7 +838,7 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
 {
 	struct nfsd4_callback *cb = calldata;
 	struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
-	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	struct nfs4_client *clp = cb->cb_clp;
 	struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
 
 	nfsd4_cb_done(task, calldata);

fs/nfsd/nfs4proc.c

@@ -191,9 +191,18 @@ static __be32 nfsd_check_obj_isreg(struct svc_fh *fh)
 	return nfserr_symlink;
 }
 
+static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
+{
+	if (nfsd4_has_session(cstate))
+		return;
+	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
+			&resfh->fh_handle);
+}
+
 static __be32
-do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
+do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
 {
+	struct svc_fh *current_fh = &cstate->current_fh;
 	struct svc_fh *resfh;
 	int accmode;
 	__be32 status;
@@ -252,9 +261,7 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 	if (is_create_with_attrs(open) && open->op_acl != NULL)
 		do_set_nfs4_acl(rqstp, resfh, open->op_acl, open->op_bmval);
 
-	/* set reply cache */
-	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
-			&resfh->fh_handle);
+	nfsd4_set_open_owner_reply_cache(cstate, open, resfh);
 	accmode = NFSD_MAY_NOP;
 	if (open->op_created)
 		accmode |= NFSD_MAY_OWNER_OVERRIDE;
@@ -268,8 +275,9 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 }
 
 static __be32
-do_open_fhandle(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
+do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
 {
+	struct svc_fh *current_fh = &cstate->current_fh;
 	__be32 status;
 
 	/* We don't know the target directory, and therefore can not
@@ -278,9 +286,7 @@ do_open_fhandle(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_
 
 	memset(&open->op_cinfo, 0, sizeof(struct nfsd4_change_info));
 
-	/* set replay cache */
-	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
-			&current_fh->fh_handle);
+	nfsd4_set_open_owner_reply_cache(cstate, open, current_fh);
 
 	open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
 		(open->op_iattr.ia_size == 0);
@@ -351,6 +357,10 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	}
 	if (status)
 		goto out;
+	if (open->op_xdr_error) {
+		status = open->op_xdr_error;
+		goto out;
+	}
 
 	status = nfsd4_check_open_attributes(rqstp, cstate, open);
 	if (status)
@@ -368,8 +378,7 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	switch (open->op_claim_type) {
 		case NFS4_OPEN_CLAIM_DELEGATE_CUR:
 		case NFS4_OPEN_CLAIM_NULL:
-			status = do_open_lookup(rqstp, &cstate->current_fh,
-						open);
+			status = do_open_lookup(rqstp, cstate, open);
 			if (status)
 				goto out;
 			break;
@@ -382,8 +391,7 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 				goto out;
 		case NFS4_OPEN_CLAIM_FH:
 		case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
-			status = do_open_fhandle(rqstp, &cstate->current_fh,
-						 open);
+			status = do_open_fhandle(rqstp, cstate, open);
 			if (status)
 				goto out;
 			break;
@@ -409,13 +417,32 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	WARN_ON(status && open->op_created);
 out:
 	nfsd4_cleanup_open_state(open, status);
-	if (open->op_openowner)
+	if (open->op_openowner && !nfsd4_has_session(cstate))
 		cstate->replay_owner = &open->op_openowner->oo_owner;
-	else
+	nfsd4_bump_seqid(cstate, status);
+	if (!cstate->replay_owner)
 		nfs4_unlock_state();
 	return status;
 }
 
+/*
+ * OPEN is the only seqid-mutating operation whose decoding can fail
+ * with a seqid-mutating error (specifically, decoding of user names in
+ * the attributes).  Therefore we have to do some processing to look up
+ * the stateowner so that we can bump the seqid.
+ */
+static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
+{
+	struct nfsd4_open *open = (struct nfsd4_open *)&op->u;
+
+	if (!seqid_mutating_err(ntohl(op->status)))
+		return op->status;
+	if (nfsd4_has_session(cstate))
+		return op->status;
+	open->op_xdr_error = op->status;
+	return nfsd4_open(rqstp, cstate, open);
+}
+
 /*
  * filehandle-manipulating ops.
  */
@@ -786,21 +813,11 @@ nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	status = nfsd_rename(rqstp, &cstate->save_fh, rename->rn_sname,
 			     rename->rn_snamelen, &cstate->current_fh,
 			     rename->rn_tname, rename->rn_tnamelen);
-
-	/* the underlying filesystem returns different error's than required
-	 * by NFSv4. both save_fh and current_fh have been verified.. */
-	if (status == nfserr_isdir)
-		status = nfserr_exist;
-	else if ((status == nfserr_notdir) &&
-                  (S_ISDIR(cstate->save_fh.fh_dentry->d_inode->i_mode) &&
-                   S_ISDIR(cstate->current_fh.fh_dentry->d_inode->i_mode)))
-		status = nfserr_exist;
-
-	if (!status) {
-		set_change_info(&rename->rn_sinfo, &cstate->current_fh);
-		set_change_info(&rename->rn_tinfo, &cstate->save_fh);
-	}
-	return status;
+	if (status)
+		return status;
+	set_change_info(&rename->rn_sinfo, &cstate->current_fh);
+	set_change_info(&rename->rn_tinfo, &cstate->save_fh);
+	return nfs_ok;
 }
 
 static __be32
@@ -931,14 +948,14 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	nfs4_lock_state();
 	status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
 					cstate, stateid, WR_STATE, &filp);
-	if (filp)
-		get_file(filp);
-	nfs4_unlock_state();
-
 	if (status) {
+		nfs4_unlock_state();
 		dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
 		return status;
 	}
+	if (filp)
+		get_file(filp);
+	nfs4_unlock_state();
 
 	cnt = write->wr_buflen;
 	write->wr_how_written = write->wr_stable_how;
@@ -1244,8 +1261,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 		 * for example, if there is a miscellaneous XDR error
 		 * it will be set to nfserr_bad_xdr.
 		 */
-		if (op->status)
+		if (op->status) {
+			if (op->opnum == OP_OPEN)
+				op->status = nfsd4_open_omfg(rqstp, cstate, op);
 			goto encode_op;
+		}
 
 		/* We must be able to encode a successful response to
 		 * this operation, with enough room left over to encode a
@@ -1282,12 +1302,9 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 		if (op->status)
 			goto encode_op;
 
-		if (opdesc->op_func) {
-			if (opdesc->op_get_currentstateid)
-				opdesc->op_get_currentstateid(cstate, &op->u);
-			op->status = opdesc->op_func(rqstp, cstate, &op->u);
-		} else
-			BUG_ON(op->status == nfs_ok);
+		if (opdesc->op_get_currentstateid)
+			opdesc->op_get_currentstateid(cstate, &op->u);
+		op->status = opdesc->op_func(rqstp, cstate, &op->u);
 
 		if (!op->status) {
 			if (opdesc->op_set_currentstateid)