[PATCH] knfsd: Allow run-time selection of NFS versions to export
Provide a file in the NFSD filesystem that allows setting and querying of
which version of NFS are being exported. Changes are only allowed while no
server is running.
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 2a99a0b..a0871b3 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -23,6 +23,7 @@
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/init.h>
+#include <linux/string.h>
#include <linux/nfs.h>
#include <linux/nfsd_idmap.h>
@@ -35,6 +36,8 @@
#include <asm/uaccess.h>
+unsigned int nfsd_versbits = ~0;
+
/*
* We have a single directory with 9 nodes in it.
*/
@@ -50,8 +53,15 @@
NFSD_List,
NFSD_Fh,
NFSD_Threads,
+ NFSD_Versions,
+ /*
+ * The below MUST come last. Otherwise we leave a hole in nfsd_files[]
+ * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
+ */
+#ifdef CONFIG_NFSD_V4
NFSD_Leasetime,
NFSD_RecoveryDir,
+#endif
};
/*
@@ -66,8 +76,11 @@
static ssize_t write_getfs(struct file *file, char *buf, size_t size);
static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
static ssize_t write_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_versions(struct file *file, char *buf, size_t size);
+#ifdef CONFIG_NFSD_V4
static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
+#endif
static ssize_t (*write_op[])(struct file *, char *, size_t) = {
[NFSD_Svc] = write_svc,
@@ -79,8 +92,11 @@
[NFSD_Getfs] = write_getfs,
[NFSD_Fh] = write_filehandle,
[NFSD_Threads] = write_threads,
+ [NFSD_Versions] = write_versions,
+#ifdef CONFIG_NFSD_V4
[NFSD_Leasetime] = write_leasetime,
[NFSD_RecoveryDir] = write_recoverydir,
+#endif
};
static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
@@ -343,6 +359,70 @@
return strlen(buf);
}
+static ssize_t write_versions(struct file *file, char *buf, size_t size)
+{
+ /*
+ * Format:
+ * [-/+]vers [-/+]vers ...
+ */
+ char *mesg = buf;
+ char *vers, sign;
+ int len, num;
+ ssize_t tlen = 0;
+ char *sep;
+
+ if (size>0) {
+ if (nfsd_serv)
+ return -EBUSY;
+ if (buf[size-1] != '\n')
+ return -EINVAL;
+ buf[size-1] = 0;
+
+ vers = mesg;
+ len = qword_get(&mesg, vers, size);
+ if (len <= 0) return -EINVAL;
+ do {
+ sign = *vers;
+ if (sign == '+' || sign == '-')
+ num = simple_strtol((vers+1), NULL, 0);
+ else
+ num = simple_strtol(vers, NULL, 0);
+ switch(num) {
+ case 2:
+ case 3:
+ case 4:
+ if (sign != '-')
+ NFSCTL_VERSET(nfsd_versbits, num);
+ else
+ NFSCTL_VERUNSET(nfsd_versbits, num);
+ break;
+ default:
+ return -EINVAL;
+ }
+ vers += len + 1;
+ tlen += len;
+ } while ((len = qword_get(&mesg, vers, size)) > 0);
+ /* If all get turned off, turn them back on, as
+ * having no versions is BAD
+ */
+ if ((nfsd_versbits & NFSCTL_VERALL)==0)
+ nfsd_versbits = NFSCTL_VERALL;
+ }
+ /* Now write current state into reply buffer */
+ len = 0;
+ sep = "";
+ for (num=2 ; num <= 4 ; num++)
+ if (NFSCTL_VERISSET(NFSCTL_VERALL, num)) {
+ len += sprintf(buf+len, "%s%c%d", sep,
+ NFSCTL_VERISSET(nfsd_versbits, num)?'+':'-',
+ num);
+ sep = " ";
+ }
+ len += sprintf(buf+len, "\n");
+ return len;
+}
+
+#ifdef CONFIG_NFSD_V4
extern time_t nfs4_leasetime(void);
static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
@@ -384,6 +464,7 @@
status = nfs4_reset_recoverydir(recdir);
return strlen(buf);
}
+#endif
/*----------------------------------------------------------------------------*/
/*
@@ -403,6 +484,7 @@
[NFSD_List] = {"exports", &exports_operations, S_IRUGO},
[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
+ [NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
#ifdef CONFIG_NFSD_V4
[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},