1 files changed, 57 insertions, 34 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index f3b2f34b10a3..6493df6b1bd5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -536,12 +536,32 @@ out_free:
 	return rv;
 }
 
+static ssize_t
+nfsd_print_version_support(char *buf, int remaining, const char *sep,
+		unsigned vers, int minor)
+{
+	const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
+	bool supported = !!nfsd_vers(vers, NFSD_TEST);
+
+	if (vers == 4 && minor >= 0 &&
+	    !nfsd_minorversion(minor, NFSD_TEST))
+		supported = false;
+	if (minor == 0 && supported)
+		/*
+		 * special case for backward compatability.
+		 * +4.0 is never reported, it is implied by
+		 * +4, unless -4.0 is present.
+		 */
+		return 0;
+	return snprintf(buf, remaining, format, sep,
+			supported ? '+' : '-', vers, minor);
+}
+
 static ssize_t __write_versions(struct file *file, char *buf, size_t size)
 {
 	char *mesg = buf;
 	char *vers, *minorp, sign;
 	int len, num, remaining;
-	unsigned minor;
 	ssize_t tlen = 0;
 	char *sep;
 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
@@ -561,6 +581,8 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
 		len = qword_get(&mesg, vers, size);
 		if (len <= 0) return -EINVAL;
 		do {
+			enum vers_op cmd;
+			unsigned minor;
 			sign = *vers;
 			if (sign == '+' || sign == '-')
 				num = simple_strtol((vers+1), &minorp, 0);
@@ -569,24 +591,34 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
 			if (*minorp == '.') {
 				if (num != 4)
 					return -EINVAL;
-				minor = simple_strtoul(minorp+1, NULL, 0);
-				if (minor == 0)
-					return -EINVAL;
-				if (nfsd_minorversion(minor, sign == '-' ?
-						     NFSD_CLEAR : NFSD_SET) < 0)
+				if (kstrtouint(minorp+1, 0, &minor) < 0)
 					return -EINVAL;
-				goto next;
 			}
+
+			cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
 			switch(num) {
 			case 2:
 			case 3:
+				nfsd_vers(num, cmd);
+				break;
 			case 4:
-				nfsd_vers(num, sign == '-' ? NFSD_CLEAR : NFSD_SET);
+				if (*minorp == '.') {
+					if (nfsd_minorversion(minor, cmd) < 0)
+						return -EINVAL;
+				} else if ((cmd == NFSD_SET) != nfsd_vers(num, NFSD_TEST)) {
+					/*
+					 * Either we have +4 and no minors are enabled,
+					 * or we have -4 and at least one minor is enabled.
+					 * In either case, propagate 'cmd' to all minors.
+					 */
+					minor = 0;
+					while (nfsd_minorversion(minor, cmd) >= 0)
+						minor++;
+				}
 				break;
 			default:
 				return -EINVAL;
 			}
-		next:
 			vers += len + 1;
 		} while ((len = qword_get(&mesg, vers, size)) > 0);
 		/* If all get turned off, turn them back on, as
@@ -599,35 +631,26 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
 	len = 0;
 	sep = "";
 	remaining = SIMPLE_TRANSACTION_LIMIT;
-	for (num=2 ; num <= 4 ; num++)
-		if (nfsd_vers(num, NFSD_AVAIL)) {
-			len = snprintf(buf, remaining, "%s%c%d", sep,
-				       nfsd_vers(num, NFSD_TEST)?'+':'-',
-				       num);
-			sep = " ";
-
-			if (len >= remaining)
-				break;
-			remaining -= len;
-			buf += len;
-			tlen += len;
-		}
-	if (nfsd_vers(4, NFSD_AVAIL))
-		for (minor = 1; minor <= NFSD_SUPPORTED_MINOR_VERSION;
-		     minor++) {
-			len = snprintf(buf, remaining, " %c4.%u",
-					(nfsd_vers(4, NFSD_TEST) &&
-					 nfsd_minorversion(minor, NFSD_TEST)) ?
-						'+' : '-',
-					minor);
+	for (num=2 ; num <= 4 ; num++) {
+		int minor;
+		if (!nfsd_vers(num, NFSD_AVAIL))
+			continue;
 
+		minor = -1;
+		do {
+			len = nfsd_print_version_support(buf, remaining,
+					sep, num, minor);
 			if (len >= remaining)
-				break;
+				goto out;
 			remaining -= len;
 			buf += len;
 			tlen += len;
-		}
-
+			minor++;
+			if (len)
+				sep = " ";
+		} while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
+	}
+out:
 	len = snprintf(buf, remaining, "\n");
 	if (len >= remaining)
 		return -EINVAL;
@@ -1123,7 +1146,7 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
 
 static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 {
-	static struct tree_descr nfsd_files[] = {
+	static const struct tree_descr nfsd_files[] = {
 		[NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
 		[NFSD_Export_features] = {"export_features",
 					&export_features_operations, S_IRUGO},