Writing to /proc/fs/nfsd/versions allows individual major versions and NFSv4 minor versions to be enabled or disabled. However NFSv4.0 cannot currently be disabled, thought there is no good reason. Also the minor number is parsed as a 'long' but used as an 'int' so '4294967297' will be incorrectly treated as '1'. This patch removes the test on 'minor == 0' and switches to kstrtouint() to get correct range checking. When reading from /proc/fs/nfsd/versions, 4.0 is current not reported. To allow the disabling for v4.0 to be visible, while maintaining backward compatibility, change code to report "-4.0" if appropriate, but not "+4.0". Signed-off-by: NeilBrown --- fs/nfsd/nfsctl.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index f3b2f34b10a3..d54fb0e3f30e 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -569,8 +569,7 @@ 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) + if (kstrtouint(minorp+1, 0, &minor) < 0) return -EINVAL; if (nfsd_minorversion(minor, sign == '-' ? NFSD_CLEAR : NFSD_SET) < 0) @@ -613,8 +612,13 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size) tlen += len; } if (nfsd_vers(4, NFSD_AVAIL)) - for (minor = 1; minor <= NFSD_SUPPORTED_MINOR_VERSION; + for (minor = 0; minor <= NFSD_SUPPORTED_MINOR_VERSION; minor++) { + if (minor == 0 && nfsd_minorversion(minor, NFSD_TEST)) + /* for backward compatibility, don't report + * +4.0 + */ + continue; len = snprintf(buf, remaining, " %c4.%u", (nfsd_vers(4, NFSD_TEST) && nfsd_minorversion(minor, NFSD_TEST)) ? -- 2.11.0