1 files changed, 33 insertions, 10 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 73e75ac90525..8bf8f667a8cf 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -538,13 +538,21 @@ out_free:
 
 static ssize_t
 nfsd_print_version_support(char *buf, int remaining, const char *sep,
-                unsigned vers, unsigned minor)
+                unsigned vers, int minor)
 {
-        const char *format = (minor == 0) ? "%s%c%u" : "%s%c%u.%u";
+        const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
         bool supported = !!nfsd_vers(vers, NFSD_TEST);
 
-        if (vers == 4 && !nfsd_minorversion(minor, 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);
 }
@@ -554,7 +562,6 @@ 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);
@@ -575,6 +582,7 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t 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);
@@ -585,8 +593,8 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                                         return -EINVAL;
                                 if (kstrtouint(minorp+1, 0, &minor) < 0)
                                         return -EINVAL;
-                        } else
-                                minor = 0;
+                        }
+
                         cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
                         switch(num) {
                         case 2:
@@ -594,8 +602,20 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                                 nfsd_vers(num, cmd);
                                 break;
                         case 4:
-                                if (nfsd_minorversion(minor, cmd) >= 0)
-                                        break;
+                                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;
                         }
@@ -612,9 +632,11 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
         sep = "";
         remaining = SIMPLE_TRANSACTION_LIMIT;
         for (num=2 ; num <= 4 ; num++) {
+                int minor;
                 if (!nfsd_vers(num, NFSD_AVAIL))
                         continue;
-                minor = 0;
+
+                minor = -1;
                 do {
                         len = nfsd_print_version_support(buf, remaining,
                                         sep, num, minor);
@@ -624,7 +646,8 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                         buf += len;
                         tlen += len;
                         minor++;
-                        sep = " ";
+                        if (len)
+                                sep = " ";
                 } while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
         }
 out: