Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / nfsd / nfsctl.c
diff --git a/kernel/fs/nfsd/nfsctl.c b/kernel/fs/nfsd/nfsctl.c
new file mode 100644 (file)
index 0000000..9690cb4
--- /dev/null
@@ -0,0 +1,1318 @@
+/*
+ * Syscall interface to knfsd.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/ctype.h>
+
+#include <linux/sunrpc/svcsock.h>
+#include <linux/lockd/lockd.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/gss_krb5_enctypes.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/module.h>
+
+#include "idmap.h"
+#include "nfsd.h"
+#include "cache.h"
+#include "state.h"
+#include "netns.h"
+#include "pnfs.h"
+
+/*
+ *     We have a single directory with several nodes in it.
+ */
+enum {
+       NFSD_Root = 1,
+       NFSD_List,
+       NFSD_Export_features,
+       NFSD_Fh,
+       NFSD_FO_UnlockIP,
+       NFSD_FO_UnlockFS,
+       NFSD_Threads,
+       NFSD_Pool_Threads,
+       NFSD_Pool_Stats,
+       NFSD_Reply_Cache_Stats,
+       NFSD_Versions,
+       NFSD_Ports,
+       NFSD_MaxBlkSize,
+       NFSD_MaxConnections,
+       NFSD_SupportedEnctypes,
+       /*
+        * 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_Gracetime,
+       NFSD_RecoveryDir,
+       NFSD_V4EndGrace,
+#endif
+};
+
+/*
+ * write() for these nodes.
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_fs(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_pool_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_versions(struct file *file, char *buf, size_t size);
+static ssize_t write_ports(struct file *file, char *buf, size_t size);
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
+static ssize_t write_maxconn(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_gracetime(struct file *file, char *buf, size_t size);
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size);
+#endif
+
+static ssize_t (*write_op[])(struct file *, char *, size_t) = {
+       [NFSD_Fh] = write_filehandle,
+       [NFSD_FO_UnlockIP] = write_unlock_ip,
+       [NFSD_FO_UnlockFS] = write_unlock_fs,
+       [NFSD_Threads] = write_threads,
+       [NFSD_Pool_Threads] = write_pool_threads,
+       [NFSD_Versions] = write_versions,
+       [NFSD_Ports] = write_ports,
+       [NFSD_MaxBlkSize] = write_maxblksize,
+       [NFSD_MaxConnections] = write_maxconn,
+#ifdef CONFIG_NFSD_V4
+       [NFSD_Leasetime] = write_leasetime,
+       [NFSD_Gracetime] = write_gracetime,
+       [NFSD_RecoveryDir] = write_recoverydir,
+       [NFSD_V4EndGrace] = write_v4_end_grace,
+#endif
+};
+
+static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
+{
+       ino_t ino =  file_inode(file)->i_ino;
+       char *data;
+       ssize_t rv;
+
+       if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
+               return -EINVAL;
+
+       data = simple_transaction_get(file, buf, size);
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       rv =  write_op[ino](file, data, size);
+       if (rv >= 0) {
+               simple_transaction_set(file, rv);
+               rv = size;
+       }
+       return rv;
+}
+
+static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+       if (! file->private_data) {
+               /* An attempt to read a transaction file without writing
+                * causes a 0-byte write so that the file can return
+                * state information
+                */
+               ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
+               if (rv < 0)
+                       return rv;
+       }
+       return simple_transaction_read(file, buf, size, pos);
+}
+
+static const struct file_operations transaction_ops = {
+       .write          = nfsctl_transaction_write,
+       .read           = nfsctl_transaction_read,
+       .release        = simple_transaction_release,
+       .llseek         = default_llseek,
+};
+
+static int exports_net_open(struct net *net, struct file *file)
+{
+       int err;
+       struct seq_file *seq;
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+       err = seq_open(file, &nfs_exports_op);
+       if (err)
+               return err;
+
+       seq = file->private_data;
+       seq->private = nn->svc_export_cache;
+       return 0;
+}
+
+static int exports_proc_open(struct inode *inode, struct file *file)
+{
+       return exports_net_open(current->nsproxy->net_ns, file);
+}
+
+static const struct file_operations exports_proc_operations = {
+       .open           = exports_proc_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+       .owner          = THIS_MODULE,
+};
+
+static int exports_nfsd_open(struct inode *inode, struct file *file)
+{
+       return exports_net_open(inode->i_sb->s_fs_info, file);
+}
+
+static const struct file_operations exports_nfsd_operations = {
+       .open           = exports_nfsd_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+       .owner          = THIS_MODULE,
+};
+
+static int export_features_show(struct seq_file *m, void *v)
+{
+       seq_printf(m, "0x%x 0x%x\n", NFSEXP_ALLFLAGS, NFSEXP_SECINFO_FLAGS);
+       return 0;
+}
+
+static int export_features_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, export_features_show, NULL);
+}
+
+static const struct file_operations export_features_operations = {
+       .open           = export_features_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
+static int supported_enctypes_show(struct seq_file *m, void *v)
+{
+       seq_printf(m, KRB5_SUPPORTED_ENCTYPES);
+       return 0;
+}
+
+static int supported_enctypes_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, supported_enctypes_show, NULL);
+}
+
+static const struct file_operations supported_enctypes_ops = {
+       .open           = supported_enctypes_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
+
+static const struct file_operations pool_stats_operations = {
+       .open           = nfsd_pool_stats_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = nfsd_pool_stats_release,
+       .owner          = THIS_MODULE,
+};
+
+static struct file_operations reply_cache_stats_operations = {
+       .open           = nfsd_reply_cache_stats_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+/*----------------------------------------------------------------------------*/
+/*
+ * payload - write methods
+ */
+
+static inline struct net *netns(struct file *file)
+{
+       return file_inode(file)->i_sb->s_fs_info;
+}
+
+/**
+ * write_unlock_ip - Release all locks used by a client
+ *
+ * Experimental.
+ *
+ * Input:
+ *                     buf:    '\n'-terminated C string containing a
+ *                             presentation format IP address
+ *                     size:   length of C string in @buf
+ * Output:
+ *     On success:     returns zero if all specified locks were released;
+ *                     returns one if one or more locks were not released
+ *     On error:       return code is negative errno value
+ */
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
+{
+       struct sockaddr_storage address;
+       struct sockaddr *sap = (struct sockaddr *)&address;
+       size_t salen = sizeof(address);
+       char *fo_path;
+       struct net *net = netns(file);
+
+       /* sanity check */
+       if (size == 0)
+               return -EINVAL;
+
+       if (buf[size-1] != '\n')
+               return -EINVAL;
+
+       fo_path = buf;
+       if (qword_get(&buf, fo_path, size) < 0)
+               return -EINVAL;
+
+       if (rpc_pton(net, fo_path, size, sap, salen) == 0)
+               return -EINVAL;
+
+       return nlmsvc_unlock_all_by_ip(sap);
+}
+
+/**
+ * write_unlock_fs - Release all locks on a local file system
+ *
+ * Experimental.
+ *
+ * Input:
+ *                     buf:    '\n'-terminated C string containing the
+ *                             absolute pathname of a local file system
+ *                     size:   length of C string in @buf
+ * Output:
+ *     On success:     returns zero if all specified locks were released;
+ *                     returns one if one or more locks were not released
+ *     On error:       return code is negative errno value
+ */
+static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
+{
+       struct path path;
+       char *fo_path;
+       int error;
+
+       /* sanity check */
+       if (size == 0)
+               return -EINVAL;
+
+       if (buf[size-1] != '\n')
+               return -EINVAL;
+
+       fo_path = buf;
+       if (qword_get(&buf, fo_path, size) < 0)
+               return -EINVAL;
+
+       error = kern_path(fo_path, 0, &path);
+       if (error)
+               return error;
+
+       /*
+        * XXX: Needs better sanity checking.  Otherwise we could end up
+        * releasing locks on the wrong file system.
+        *
+        * For example:
+        * 1.  Does the path refer to a directory?
+        * 2.  Is that directory a mount point, or
+        * 3.  Is that directory the root of an exported file system?
+        */
+       error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
+
+       path_put(&path);
+       return error;
+}
+
+/**
+ * write_filehandle - Get a variable-length NFS file handle by path
+ *
+ * On input, the buffer contains a '\n'-terminated C string comprised of
+ * three alphanumeric words separated by whitespace.  The string may
+ * contain escape sequences.
+ *
+ * Input:
+ *                     buf:
+ *                             domain:         client domain name
+ *                             path:           export pathname
+ *                             maxsize:        numeric maximum size of
+ *                                             @buf
+ *                     size:   length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C
+ *                     string containing a ASCII hex text version
+ *                     of the NFS file handle;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is negative errno value
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
+{
+       char *dname, *path;
+       int uninitialized_var(maxsize);
+       char *mesg = buf;
+       int len;
+       struct auth_domain *dom;
+       struct knfsd_fh fh;
+
+       if (size == 0)
+               return -EINVAL;
+
+       if (buf[size-1] != '\n')
+               return -EINVAL;
+       buf[size-1] = 0;
+
+       dname = mesg;
+       len = qword_get(&mesg, dname, size);
+       if (len <= 0)
+               return -EINVAL;
+       
+       path = dname+len+1;
+       len = qword_get(&mesg, path, size);
+       if (len <= 0)
+               return -EINVAL;
+
+       len = get_int(&mesg, &maxsize);
+       if (len)
+               return len;
+
+       if (maxsize < NFS_FHSIZE)
+               return -EINVAL;
+       maxsize = min(maxsize, NFS3_FHSIZE);
+
+       if (qword_get(&mesg, mesg, size)>0)
+               return -EINVAL;
+
+       /* we have all the words, they are in buf.. */
+       dom = unix_domain_find(dname);
+       if (!dom)
+               return -ENOMEM;
+
+       len = exp_rootfh(netns(file), dom, path, &fh,  maxsize);
+       auth_domain_put(dom);
+       if (len)
+               return len;
+       
+       mesg = buf;
+       len = SIMPLE_TRANSACTION_LIMIT;
+       qword_addhex(&mesg, &len, (char*)&fh.fh_base, fh.fh_size);
+       mesg[-1] = '\n';
+       return mesg - buf;      
+}
+
+/**
+ * write_threads - Start NFSD, or report the current number of running threads
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C
+ *                     string numeric value representing the number of
+ *                     running NFSD threads;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing an unsigned
+ *                                     integer value representing the
+ *                                     number of NFSD threads to start
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     NFS service is started;
+ *                     passed-in buffer filled with '\n'-terminated C
+ *                     string numeric value representing the number of
+ *                     running NFSD threads;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_threads(struct file *file, char *buf, size_t size)
+{
+       char *mesg = buf;
+       int rv;
+       struct net *net = netns(file);
+
+       if (size > 0) {
+               int newthreads;
+               rv = get_int(&mesg, &newthreads);
+               if (rv)
+                       return rv;
+               if (newthreads < 0)
+                       return -EINVAL;
+               rv = nfsd_svc(newthreads, net);
+               if (rv < 0)
+                       return rv;
+       } else
+               rv = nfsd_nrthreads(net);
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n", rv);
+}
+
+/**
+ * write_pool_threads - Set or report the current number of threads per pool
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing whitespace-
+ *                                     separated unsigned integer values
+ *                                     representing the number of NFSD
+ *                                     threads to start in each pool
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C
+ *                     string containing integer values representing the
+ *                     number of NFSD threads in each pool;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+{
+       /* if size > 0, look for an array of number of threads per node
+        * and apply them  then write out number of threads per node as reply
+        */
+       char *mesg = buf;
+       int i;
+       int rv;
+       int len;
+       int npools;
+       int *nthreads;
+       struct net *net = netns(file);
+
+       mutex_lock(&nfsd_mutex);
+       npools = nfsd_nrpools(net);
+       if (npools == 0) {
+               /*
+                * NFS is shut down.  The admin can start it by
+                * writing to the threads file but NOT the pool_threads
+                * file, sorry.  Report zero threads.
+                */
+               mutex_unlock(&nfsd_mutex);
+               strcpy(buf, "0\n");
+               return strlen(buf);
+       }
+
+       nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
+       rv = -ENOMEM;
+       if (nthreads == NULL)
+               goto out_free;
+
+       if (size > 0) {
+               for (i = 0; i < npools; i++) {
+                       rv = get_int(&mesg, &nthreads[i]);
+                       if (rv == -ENOENT)
+                               break;          /* fewer numbers than pools */
+                       if (rv)
+                               goto out_free;  /* syntax error */
+                       rv = -EINVAL;
+                       if (nthreads[i] < 0)
+                               goto out_free;
+               }
+               rv = nfsd_set_nrthreads(i, nthreads, net);
+               if (rv)
+                       goto out_free;
+       }
+
+       rv = nfsd_get_nrthreads(npools, nthreads, net);
+       if (rv)
+               goto out_free;
+
+       mesg = buf;
+       size = SIMPLE_TRANSACTION_LIMIT;
+       for (i = 0; i < npools && size > 0; i++) {
+               snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
+               len = strlen(mesg);
+               size -= len;
+               mesg += len;
+       }
+       rv = mesg - buf;
+out_free:
+       kfree(nthreads);
+       mutex_unlock(&nfsd_mutex);
+       return rv;
+}
+
+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);
+
+       if (size>0) {
+               if (nn->nfsd_serv)
+                       /* Cannot change versions without updating
+                        * nn->nfsd_serv->sv_xdrsize, and reallocing
+                        * rq_argp and rq_resp
+                        */
+                       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), &minorp, 0);
+                       else
+                               num = simple_strtol(vers, &minorp, 0);
+                       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)
+                                       return -EINVAL;
+                               goto next;
+                       }
+                       switch(num) {
+                       case 2:
+                       case 3:
+                       case 4:
+                               nfsd_vers(num, sign == '-' ? NFSD_CLEAR : NFSD_SET);
+                               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
+                * having no versions is BAD
+                */
+               nfsd_reset_versions();
+       }
+
+       /* Now write current state into reply buffer */
+       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);
+
+                       if (len >= remaining)
+                               break;
+                       remaining -= len;
+                       buf += len;
+                       tlen += len;
+               }
+
+       len = snprintf(buf, remaining, "\n");
+       if (len >= remaining)
+               return -EINVAL;
+       return tlen + len;
+}
+
+/**
+ * write_versions - Set or report the available NFS protocol versions
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C
+ *                     string containing positive or negative integer
+ *                     values representing the current status of each
+ *                     protocol version;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing whitespace-
+ *                                     separated positive or negative
+ *                                     integer values representing NFS
+ *                                     protocol versions to enable ("+n")
+ *                                     or disable ("-n")
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     status of zero or more protocol versions has
+ *                     been updated; passed-in buffer filled with
+ *                     '\n'-terminated C string containing positive
+ *                     or negative integer values representing the
+ *                     current status of each protocol version;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_versions(struct file *file, char *buf, size_t size)
+{
+       ssize_t rv;
+
+       mutex_lock(&nfsd_mutex);
+       rv = __write_versions(file, buf, size);
+       mutex_unlock(&nfsd_mutex);
+       return rv;
+}
+
+/*
+ * Zero-length write.  Return a list of NFSD's current listener
+ * transports.
+ */
+static ssize_t __write_ports_names(char *buf, struct net *net)
+{
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+       if (nn->nfsd_serv == NULL)
+               return 0;
+       return svc_xprt_names(nn->nfsd_serv, buf, SIMPLE_TRANSACTION_LIMIT);
+}
+
+/*
+ * A single 'fd' number was written, in which case it must be for
+ * a socket of a supported family/protocol, and we use it as an
+ * nfsd listener.
+ */
+static ssize_t __write_ports_addfd(char *buf, struct net *net)
+{
+       char *mesg = buf;
+       int fd, err;
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+       err = get_int(&mesg, &fd);
+       if (err != 0 || fd < 0)
+               return -EINVAL;
+
+       if (svc_alien_sock(net, fd)) {
+               printk(KERN_ERR "%s: socket net is different to NFSd's one\n", __func__);
+               return -EINVAL;
+       }
+
+       err = nfsd_create_serv(net);
+       if (err != 0)
+               return err;
+
+       err = svc_addsock(nn->nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT);
+       if (err < 0) {
+               nfsd_destroy(net);
+               return err;
+       }
+
+       /* Decrease the count, but don't shut down the service */
+       nn->nfsd_serv->sv_nrthreads--;
+       return err;
+}
+
+/*
+ * A transport listener is added by writing it's transport name and
+ * a port number.
+ */
+static ssize_t __write_ports_addxprt(char *buf, struct net *net)
+{
+       char transport[16];
+       struct svc_xprt *xprt;
+       int port, err;
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+       if (sscanf(buf, "%15s %5u", transport, &port) != 2)
+               return -EINVAL;
+
+       if (port < 1 || port > USHRT_MAX)
+               return -EINVAL;
+
+       err = nfsd_create_serv(net);
+       if (err != 0)
+               return err;
+
+       err = svc_create_xprt(nn->nfsd_serv, transport, net,
+                               PF_INET, port, SVC_SOCK_ANONYMOUS);
+       if (err < 0)
+               goto out_err;
+
+       err = svc_create_xprt(nn->nfsd_serv, transport, net,
+                               PF_INET6, port, SVC_SOCK_ANONYMOUS);
+       if (err < 0 && err != -EAFNOSUPPORT)
+               goto out_close;
+
+       /* Decrease the count, but don't shut down the service */
+       nn->nfsd_serv->sv_nrthreads--;
+       return 0;
+out_close:
+       xprt = svc_find_xprt(nn->nfsd_serv, transport, net, PF_INET, port);
+       if (xprt != NULL) {
+               svc_close_xprt(xprt);
+               svc_xprt_put(xprt);
+       }
+out_err:
+       nfsd_destroy(net);
+       return err;
+}
+
+static ssize_t __write_ports(struct file *file, char *buf, size_t size,
+                            struct net *net)
+{
+       if (size == 0)
+               return __write_ports_names(buf, net);
+
+       if (isdigit(buf[0]))
+               return __write_ports_addfd(buf, net);
+
+       if (isalpha(buf[0]))
+               return __write_ports_addxprt(buf, net);
+
+       return -EINVAL;
+}
+
+/**
+ * write_ports - Pass a socket file descriptor or transport name to listen on
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ * Output:
+ *     On success:     passed-in buffer filled with a '\n'-terminated C
+ *                     string containing a whitespace-separated list of
+ *                     named NFSD listeners;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing an unsigned
+ *                                     integer value representing a bound
+ *                                     but unconnected socket that is to be
+ *                                     used as an NFSD listener; listen(3)
+ *                                     must be called for a SOCK_STREAM
+ *                                     socket, otherwise it is ignored
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     NFS service is started;
+ *                     passed-in buffer filled with a '\n'-terminated C
+ *                     string containing a unique alphanumeric name of
+ *                     the listener;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing a transport
+ *                                     name and an unsigned integer value
+ *                                     representing the port to listen on,
+ *                                     separated by whitespace
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     returns zero; NFS service is started
+ *     On error:       return code is a negative errno value
+ */
+static ssize_t write_ports(struct file *file, char *buf, size_t size)
+{
+       ssize_t rv;
+
+       mutex_lock(&nfsd_mutex);
+       rv = __write_ports(file, buf, size, netns(file));
+       mutex_unlock(&nfsd_mutex);
+       return rv;
+}
+
+
+int nfsd_max_blksize;
+
+/**
+ * write_maxblksize - Set or report the current NFS blksize
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing an unsigned
+ *                                     integer value representing the new
+ *                                     NFS blksize
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C string
+ *                     containing numeric value of the current NFS blksize
+ *                     setting;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
+{
+       char *mesg = buf;
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+       if (size > 0) {
+               int bsize;
+               int rv = get_int(&mesg, &bsize);
+               if (rv)
+                       return rv;
+               /* force bsize into allowed range and
+                * required alignment.
+                */
+               bsize = max_t(int, bsize, 1024);
+               bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
+               bsize &= ~(1024-1);
+               mutex_lock(&nfsd_mutex);
+               if (nn->nfsd_serv) {
+                       mutex_unlock(&nfsd_mutex);
+                       return -EBUSY;
+               }
+               nfsd_max_blksize = bsize;
+               mutex_unlock(&nfsd_mutex);
+       }
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
+                                                       nfsd_max_blksize);
+}
+
+/**
+ * write_maxconn - Set or report the current max number of connections
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing an unsigned
+ *                                     integer value representing the new
+ *                                     number of max connections
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C string
+ *                     containing numeric value of max_connections setting
+ *                     for this net namespace;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
+{
+       char *mesg = buf;
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+       unsigned int maxconn = nn->max_connections;
+
+       if (size > 0) {
+               int rv = get_uint(&mesg, &maxconn);
+
+               if (rv)
+                       return rv;
+               nn->max_connections = maxconn;
+       }
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
+}
+
+#ifdef CONFIG_NFSD_V4
+static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
+                                 time_t *time, struct nfsd_net *nn)
+{
+       char *mesg = buf;
+       int rv, i;
+
+       if (size > 0) {
+               if (nn->nfsd_serv)
+                       return -EBUSY;
+               rv = get_int(&mesg, &i);
+               if (rv)
+                       return rv;
+               /*
+                * Some sanity checking.  We don't have a reason for
+                * these particular numbers, but problems with the
+                * extremes are:
+                *      - Too short: the briefest network outage may
+                *        cause clients to lose all their locks.  Also,
+                *        the frequent polling may be wasteful.
+                *      - Too long: do you really want reboot recovery
+                *        to take more than an hour?  Or to make other
+                *        clients wait an hour before being able to
+                *        revoke a dead client's locks?
+                */
+               if (i < 10 || i > 3600)
+                       return -EINVAL;
+               *time = i;
+       }
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n", *time);
+}
+
+static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
+                               time_t *time, struct nfsd_net *nn)
+{
+       ssize_t rv;
+
+       mutex_lock(&nfsd_mutex);
+       rv = __nfsd4_write_time(file, buf, size, time, nn);
+       mutex_unlock(&nfsd_mutex);
+       return rv;
+}
+
+/**
+ * write_leasetime - Set or report the current NFSv4 lease time
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing an unsigned
+ *                                     integer value representing the new
+ *                                     NFSv4 lease expiry time
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C
+ *                     string containing unsigned integer value of the
+ *                     current lease expiry time;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
+{
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+       return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
+}
+
+/**
+ * write_gracetime - Set or report current NFSv4 grace period time
+ *
+ * As above, but sets the time of the NFSv4 grace period.
+ *
+ * Note this should never be set to less than the *previous*
+ * lease-period time, but we don't try to enforce this.  (In the common
+ * case (a new boot), we don't know what the previous lease time was
+ * anyway.)
+ */
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
+{
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+       return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
+}
+
+static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
+                                  struct nfsd_net *nn)
+{
+       char *mesg = buf;
+       char *recdir;
+       int len, status;
+
+       if (size > 0) {
+               if (nn->nfsd_serv)
+                       return -EBUSY;
+               if (size > PATH_MAX || buf[size-1] != '\n')
+                       return -EINVAL;
+               buf[size-1] = 0;
+
+               recdir = mesg;
+               len = qword_get(&mesg, recdir, size);
+               if (len <= 0)
+                       return -EINVAL;
+
+               status = nfs4_reset_recoverydir(recdir);
+               if (status)
+                       return status;
+       }
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%s\n",
+                                                       nfs4_recoverydir());
+}
+
+/**
+ * write_recoverydir - Set or report the pathname of the recovery directory
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ *
+ * OR
+ *
+ * Input:
+ *                     buf:            C string containing the pathname
+ *                                     of the directory on a local file
+ *                                     system containing permanent NFSv4
+ *                                     recovery data
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *     On success:     passed-in buffer filled with '\n'-terminated C string
+ *                     containing the current recovery pathname setting;
+ *                     return code is the size in bytes of the string
+ *     On error:       return code is zero or a negative errno value
+ */
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
+{
+       ssize_t rv;
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+       mutex_lock(&nfsd_mutex);
+       rv = __write_recoverydir(file, buf, size, nn);
+       mutex_unlock(&nfsd_mutex);
+       return rv;
+}
+
+/**
+ * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
+ *
+ * Input:
+ *                     buf:            ignored
+ *                     size:           zero
+ * OR
+ *
+ * Input:
+ *                     buf:            any value
+ *                     size:           non-zero length of C string in @buf
+ * Output:
+ *                     passed-in buffer filled with "Y" or "N" with a newline
+ *                     and NULL-terminated C string. This indicates whether
+ *                     the grace period has ended in the current net
+ *                     namespace. Return code is the size in bytes of the
+ *                     string. Writing a string that starts with 'Y', 'y', or
+ *                     '1' to the file will end the grace period for nfsd's v4
+ *                     lock manager.
+ */
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
+{
+       struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+       if (size > 0) {
+               switch(buf[0]) {
+               case 'Y':
+               case 'y':
+               case '1':
+                       nfsd4_end_grace(nn);
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
+                        nn->grace_ended ? 'Y' : 'N');
+}
+
+#endif
+
+/*----------------------------------------------------------------------------*/
+/*
+ *     populating the filesystem.
+ */
+
+static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
+{
+       static struct tree_descr nfsd_files[] = {
+               [NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
+               [NFSD_Export_features] = {"export_features",
+                                       &export_features_operations, S_IRUGO},
+               [NFSD_FO_UnlockIP] = {"unlock_ip",
+                                       &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_FO_UnlockFS] = {"unlock_filesystem",
+                                       &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
+               [NFSD_Reply_Cache_Stats] = {"reply_cache_stats", &reply_cache_stats_operations, S_IRUGO},
+               [NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
+               [NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+               [NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
+               [NFSD_SupportedEnctypes] = {"supported_krb5_enctypes", &supported_enctypes_ops, S_IRUGO},
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
+#ifdef CONFIG_NFSD_V4
+               [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
+               [NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
+#endif
+               /* last one */ {""}
+       };
+       struct net *net = data;
+       int ret;
+
+       ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
+       if (ret)
+               return ret;
+       sb->s_fs_info = get_net(net);
+       return 0;
+}
+
+static struct dentry *nfsd_mount(struct file_system_type *fs_type,
+       int flags, const char *dev_name, void *data)
+{
+       return mount_ns(fs_type, flags, current->nsproxy->net_ns, nfsd_fill_super);
+}
+
+static void nfsd_umount(struct super_block *sb)
+{
+       struct net *net = sb->s_fs_info;
+
+       kill_litter_super(sb);
+       put_net(net);
+}
+
+static struct file_system_type nfsd_fs_type = {
+       .owner          = THIS_MODULE,
+       .name           = "nfsd",
+       .mount          = nfsd_mount,
+       .kill_sb        = nfsd_umount,
+};
+MODULE_ALIAS_FS("nfsd");
+
+#ifdef CONFIG_PROC_FS
+static int create_proc_exports_entry(void)
+{
+       struct proc_dir_entry *entry;
+
+       entry = proc_mkdir("fs/nfs", NULL);
+       if (!entry)
+               return -ENOMEM;
+       entry = proc_create("exports", 0, entry,
+                                &exports_proc_operations);
+       if (!entry) {
+               remove_proc_entry("fs/nfs", NULL);
+               return -ENOMEM;
+       }
+       return 0;
+}
+#else /* CONFIG_PROC_FS */
+static int create_proc_exports_entry(void)
+{
+       return 0;
+}
+#endif
+
+int nfsd_net_id;
+
+static __net_init int nfsd_init_net(struct net *net)
+{
+       int retval;
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+       retval = nfsd_export_init(net);
+       if (retval)
+               goto out_export_error;
+       retval = nfsd_idmap_init(net);
+       if (retval)
+               goto out_idmap_error;
+       nn->nfsd4_lease = 90;   /* default lease time */
+       nn->nfsd4_grace = 90;
+       return 0;
+
+out_idmap_error:
+       nfsd_export_shutdown(net);
+out_export_error:
+       return retval;
+}
+
+static __net_exit void nfsd_exit_net(struct net *net)
+{
+       nfsd_idmap_shutdown(net);
+       nfsd_export_shutdown(net);
+}
+
+static struct pernet_operations nfsd_net_ops = {
+       .init = nfsd_init_net,
+       .exit = nfsd_exit_net,
+       .id   = &nfsd_net_id,
+       .size = sizeof(struct nfsd_net),
+};
+
+static int __init init_nfsd(void)
+{
+       int retval;
+       printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@monad.swb.de).\n");
+
+       retval = register_pernet_subsys(&nfsd_net_ops);
+       if (retval < 0)
+               return retval;
+       retval = register_cld_notifier();
+       if (retval)
+               goto out_unregister_pernet;
+       retval = nfsd4_init_slabs();
+       if (retval)
+               goto out_unregister_notifier;
+       retval = nfsd4_init_pnfs();
+       if (retval)
+               goto out_free_slabs;
+       retval = nfsd_fault_inject_init(); /* nfsd fault injection controls */
+       if (retval)
+               goto out_exit_pnfs;
+       nfsd_stat_init();       /* Statistics */
+       retval = nfsd_reply_cache_init();
+       if (retval)
+               goto out_free_stat;
+       nfsd_lockd_init();      /* lockd->nfsd callbacks */
+       retval = create_proc_exports_entry();
+       if (retval)
+               goto out_free_lockd;
+       retval = register_filesystem(&nfsd_fs_type);
+       if (retval)
+               goto out_free_all;
+       return 0;
+out_free_all:
+       remove_proc_entry("fs/nfs/exports", NULL);
+       remove_proc_entry("fs/nfs", NULL);
+out_free_lockd:
+       nfsd_lockd_shutdown();
+       nfsd_reply_cache_shutdown();
+out_free_stat:
+       nfsd_stat_shutdown();
+       nfsd_fault_inject_cleanup();
+out_exit_pnfs:
+       nfsd4_exit_pnfs();
+out_free_slabs:
+       nfsd4_free_slabs();
+out_unregister_notifier:
+       unregister_cld_notifier();
+out_unregister_pernet:
+       unregister_pernet_subsys(&nfsd_net_ops);
+       return retval;
+}
+
+static void __exit exit_nfsd(void)
+{
+       nfsd_reply_cache_shutdown();
+       remove_proc_entry("fs/nfs/exports", NULL);
+       remove_proc_entry("fs/nfs", NULL);
+       nfsd_stat_shutdown();
+       nfsd_lockd_shutdown();
+       nfsd4_free_slabs();
+       nfsd4_exit_pnfs();
+       nfsd_fault_inject_cleanup();
+       unregister_filesystem(&nfsd_fs_type);
+       unregister_cld_notifier();
+       unregister_pernet_subsys(&nfsd_net_ops);
+}
+
+MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
+MODULE_LICENSE("GPL");
+module_init(init_nfsd)
+module_exit(exit_nfsd)