Merge branch 'for-3.14' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 - Handle some loose ends from the vfs read delegation support.
   (For example nfsd can stop breaking leases on its own in a
    fewer places where it can now depend on the vfs to.)
 - Make life a little easier for NFSv4-only configurations
   (thanks to Kinglong Mee).
 - Fix some gss-proxy problems (thanks Jeff Layton).
 - miscellaneous bug fixes and cleanup

* 'for-3.14' of git://linux-nfs.org/~bfields/linux: (38 commits)
  nfsd: consider CLAIM_FH when handing out delegation
  nfsd4: fix delegation-unlink/rename race
  nfsd4: delay setting current_fh in open
  nfsd4: minor nfs4_setlease cleanup
  gss_krb5: use lcm from kernel lib
  nfsd4: decrease nfsd4_encode_fattr stack usage
  nfsd: fix encode_entryplus_baggage stack usage
  nfsd4: simplify xdr encoding of nfsv4 names
  nfsd4: encode_rdattr_error cleanup
  nfsd4: nfsd4_encode_fattr cleanup
  minor svcauth_gss.c cleanup
  nfsd4: better VERIFY comment
  nfsd4: break only delegations when appropriate
  NFSD: Fix a memory leak in nfsd4_create_session
  sunrpc: get rid of use_gssp_lock
  sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt
  sunrpc: don't wait for write before allowing reads from use-gss-proxy file
  nfsd: get rid of unused function definition
  Define op_iattr for nfsd4_open instead using macro
  NFSD: fix compile warning without CONFIG_NFSD_V3
  ...

3 files changed, 26 insertions, 75 deletions

diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c
index 76e42e6be755..24589bd2a4b6 100644
--- a/net/sunrpc/auth_gss/gss_krb5_keys.c
+++ b/net/sunrpc/auth_gss/gss_krb5_keys.c
@@ -59,6 +59,7 @@
 #include <linux/crypto.h>
 #include <linux/sunrpc/gss_krb5.h>
 #include <linux/sunrpc/xdr.h>
+#include <linux/lcm.h>
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY        RPCDBG_AUTH
@@ -72,7 +73,7 @@
 static void krb5_nfold(u32 inbits, const u8 *in,
 		       u32 outbits, u8 *out)
 {
-	int a, b, c, lcm;
+	unsigned long ulcm;
 	int byte, i, msbit;
 
 	/* the code below is more readable if I make these bytes
@@ -82,17 +83,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,
 	outbits >>= 3;
 
 	/* first compute lcm(n,k) */
-
-	a = outbits;
-	b = inbits;
-
-	while (b != 0) {
-		c = b;
-		b = a%b;
-		a = c;
-	}
-
-	lcm = outbits*inbits/a;
+	ulcm = lcm(inbits, outbits);
 
 	/* now do the real work */
 
@@ -101,7 +92,7 @@ static void krb5_nfold(u32 inbits, const u8 *in,
 
 	/* this will end up cycling through k lcm(k,n)/k times, which
 	   is correct */
-	for (i = lcm-1; i >= 0; i--) {
+	for (i = ulcm-1; i >= 0; i--) {
 		/* compute the msbit in k which gets added into this byte */
 		msbit = (
 			/* first, start with the msbit in the first,
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index 458f85e9b0ba..abbb7dcd1689 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -137,7 +137,6 @@ void init_gssp_clnt(struct sunrpc_net *sn)
 {
 	mutex_init(&sn->gssp_lock);
 	sn->gssp_clnt = NULL;
-	init_waitqueue_head(&sn->gssp_wq);
 }
 
 int set_gssp_clnt(struct net *net)
@@ -154,7 +153,6 @@ int set_gssp_clnt(struct net *net)
 		sn->gssp_clnt = clnt;
 	}
 	mutex_unlock(&sn->gssp_lock);
-	wake_up(&sn->gssp_wq);
 	return ret;
 }
 
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 008cdade5aae..0f73f4507746 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1263,65 +1263,34 @@ out:
 	return ret;
 }
 
-DEFINE_SPINLOCK(use_gssp_lock);
-
-static bool use_gss_proxy(struct net *net)
-{
-	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
-
-	if (sn->use_gss_proxy != -1)
-		return sn->use_gss_proxy;
-	spin_lock(&use_gssp_lock);
-	/*
-	 * If you wanted gss-proxy, you should have said so before
-	 * starting to accept requests:
-	 */
-	sn->use_gss_proxy = 0;
-	spin_unlock(&use_gssp_lock);
-	return 0;
-}
-
-#ifdef CONFIG_PROC_FS
-
+/*
+ * Try to set the sn->use_gss_proxy variable to a new value. We only allow
+ * it to be changed if it's currently undefined (-1). If it's any other value
+ * then return -EBUSY unless the type wouldn't have changed anyway.
+ */
 static int set_gss_proxy(struct net *net, int type)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
-	int ret = 0;
+	int ret;
 
 	WARN_ON_ONCE(type != 0 && type != 1);
-	spin_lock(&use_gssp_lock);
-	if (sn->use_gss_proxy == -1 || sn->use_gss_proxy == type)
-		sn->use_gss_proxy = type;
-	else
-		ret = -EBUSY;
-	spin_unlock(&use_gssp_lock);
-	wake_up(&sn->gssp_wq);
-	return ret;
-}
-
-static inline bool gssp_ready(struct sunrpc_net *sn)
-{
-	switch (sn->use_gss_proxy) {
-		case -1:
-			return false;
-		case 0:
-			return true;
-		case 1:
-			return sn->gssp_clnt;
-	}
-	WARN_ON_ONCE(1);
-	return false;
+	ret = cmpxchg(&sn->use_gss_proxy, -1, type);
+	if (ret != -1 && ret != type)
+		return -EBUSY;
+	return 0;
 }
 
-static int wait_for_gss_proxy(struct net *net, struct file *file)
+static bool use_gss_proxy(struct net *net)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
-	if (file->f_flags & O_NONBLOCK && !gssp_ready(sn))
-		return -EAGAIN;
-	return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
+	/* If use_gss_proxy is still undefined, then try to disable it */
+	if (sn->use_gss_proxy == -1)
+		set_gss_proxy(net, 0);
+	return sn->use_gss_proxy;
 }
 
+#ifdef CONFIG_PROC_FS
 
 static ssize_t write_gssp(struct file *file, const char __user *buf,
 			 size_t count, loff_t *ppos)
@@ -1342,10 +1311,10 @@ static ssize_t write_gssp(struct file *file, const char __user *buf,
 		return res;
 	if (i != 1)
 		return -EINVAL;
-	res = set_gss_proxy(net, 1);
+	res = set_gssp_clnt(net);
 	if (res)
 		return res;
-	res = set_gssp_clnt(net);
+	res = set_gss_proxy(net, 1);
 	if (res)
 		return res;
 	return count;
@@ -1355,16 +1324,12 @@ static ssize_t read_gssp(struct file *file, char __user *buf,
 			 size_t count, loff_t *ppos)
 {
 	struct net *net = PDE_DATA(file_inode(file));
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	unsigned long p = *ppos;
 	char tbuf[10];
 	size_t len;
-	int ret;
 
-	ret = wait_for_gss_proxy(net, file);
-	if (ret)
-		return ret;
-
-	snprintf(tbuf, sizeof(tbuf), "%d\n", use_gss_proxy(net));
+	snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
 	len = strlen(tbuf);
 	if (p >= len)
 		return 0;
@@ -1626,8 +1591,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
 	BUG_ON(integ_len % 4);
 	*p++ = htonl(integ_len);
 	*p++ = htonl(gc->gc_seq);
-	if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
-				integ_len))
+	if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
 		BUG();
 	if (resbuf->tail[0].iov_base == NULL) {
 		if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
@@ -1635,10 +1599,8 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
 		resbuf->tail[0].iov_base = resbuf->head[0].iov_base
 						+ resbuf->head[0].iov_len;
 		resbuf->tail[0].iov_len = 0;
-		resv = &resbuf->tail[0];
-	} else {
-		resv = &resbuf->tail[0];
 	}
+	resv = &resbuf->tail[0];
 	mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
 	if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
 		goto out_err;