kernel_optimize_test/fs/nfsd/export.c
J. Bruce Fields 68d9318435 nfsd4: fix wrongsec handling for PUTFH + op cases
When PUTFH is followed by an operation that uses the filehandle, and
when the current client is using a security flavor that is inconsistent
with the given filehandle, we have a choice: we can return WRONGSEC
either when the current filehandle is set using the PUTFH, or when the
filehandle is first used by the following operation.

Follow the recommendations of RFC 5661 in making this choice.

(Our current behavior prevented the client from doing security
negotiation by returning WRONGSEC on PUTFH+SECINFO_NO_NAME.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-04-29 20:47:51 -04:00

1694 lines
39 KiB
C

/*
* NFS exporting and validation.
*
* We maintain a list of clients, each of which has a list of
* exports. To export an fs to a given client, you first have
* to create the client entry with NFSCTL_ADDCLIENT, which
* creates a client control block and adds it to the hash
* table. Then, you call NFSCTL_EXPORT for each fs.
*
*
* Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
*/
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/module.h>
#include <linux/exportfs.h>
#include <linux/nfsd/syscall.h>
#include <net/ipv6.h>
#include "nfsd.h"
#include "nfsfh.h"
#define NFSDDBG_FACILITY NFSDDBG_EXPORT
typedef struct auth_domain svc_client;
typedef struct svc_export svc_export;
/*
* We have two caches.
* One maps client+vfsmnt+dentry to export options - the export map
* The other maps client+filehandle-fragment to export options. - the expkey map
*
* The export options are actually stored in the first map, and the
* second map contains a reference to the entry in the first map.
*/
#define EXPKEY_HASHBITS 8
#define EXPKEY_HASHMAX (1 << EXPKEY_HASHBITS)
#define EXPKEY_HASHMASK (EXPKEY_HASHMAX -1)
static struct cache_head *expkey_table[EXPKEY_HASHMAX];
static void expkey_put(struct kref *ref)
{
struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
if (test_bit(CACHE_VALID, &key->h.flags) &&
!test_bit(CACHE_NEGATIVE, &key->h.flags))
path_put(&key->ek_path);
auth_domain_put(key->ek_client);
kfree(key);
}
static void expkey_request(struct cache_detail *cd,
struct cache_head *h,
char **bpp, int *blen)
{
/* client fsidtype \xfsid */
struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
char type[5];
qword_add(bpp, blen, ek->ek_client->name);
snprintf(type, 5, "%d", ek->ek_fsidtype);
qword_add(bpp, blen, type);
qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
(*bpp)[-1] = '\n';
}
static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
{
return sunrpc_cache_pipe_upcall(cd, h, expkey_request);
}
static struct svc_expkey *svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old);
static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *);
static struct cache_detail svc_expkey_cache;
static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
{
/* client fsidtype fsid [path] */
char *buf;
int len;
struct auth_domain *dom = NULL;
int err;
int fsidtype;
char *ep;
struct svc_expkey key;
struct svc_expkey *ek = NULL;
if (mesg[mlen-1] != '\n')
return -EINVAL;
mesg[mlen-1] = 0;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
err = -ENOMEM;
if (!buf)
goto out;
err = -EINVAL;
if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
goto out;
err = -ENOENT;
dom = auth_domain_find(buf);
if (!dom)
goto out;
dprintk("found domain %s\n", buf);
err = -EINVAL;
if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
goto out;
fsidtype = simple_strtoul(buf, &ep, 10);
if (*ep)
goto out;
dprintk("found fsidtype %d\n", fsidtype);
if (key_len(fsidtype)==0) /* invalid type */
goto out;
if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
goto out;
dprintk("found fsid length %d\n", len);
if (len != key_len(fsidtype))
goto out;
/* OK, we seem to have a valid key */
key.h.flags = 0;
key.h.expiry_time = get_expiry(&mesg);
if (key.h.expiry_time == 0)
goto out;
key.ek_client = dom;
key.ek_fsidtype = fsidtype;
memcpy(key.ek_fsid, buf, len);
ek = svc_expkey_lookup(&key);
err = -ENOMEM;
if (!ek)
goto out;
/* now we want a pathname, or empty meaning NEGATIVE */
err = -EINVAL;
len = qword_get(&mesg, buf, PAGE_SIZE);
if (len < 0)
goto out;
dprintk("Path seems to be <%s>\n", buf);
err = 0;
if (len == 0) {
set_bit(CACHE_NEGATIVE, &key.h.flags);
ek = svc_expkey_update(&key, ek);
if (!ek)
err = -ENOMEM;
} else {
err = kern_path(buf, 0, &key.ek_path);
if (err)
goto out;
dprintk("Found the path %s\n", buf);
ek = svc_expkey_update(&key, ek);
if (!ek)
err = -ENOMEM;
path_put(&key.ek_path);
}
cache_flush();
out:
if (ek)
cache_put(&ek->h, &svc_expkey_cache);
if (dom)
auth_domain_put(dom);
kfree(buf);
return err;
}
static int expkey_show(struct seq_file *m,
struct cache_detail *cd,
struct cache_head *h)
{
struct svc_expkey *ek ;
int i;
if (h ==NULL) {
seq_puts(m, "#domain fsidtype fsid [path]\n");
return 0;
}
ek = container_of(h, struct svc_expkey, h);
seq_printf(m, "%s %d 0x", ek->ek_client->name,
ek->ek_fsidtype);
for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
seq_printf(m, "%08x", ek->ek_fsid[i]);
if (test_bit(CACHE_VALID, &h->flags) &&
!test_bit(CACHE_NEGATIVE, &h->flags)) {
seq_printf(m, " ");
seq_path(m, &ek->ek_path, "\\ \t\n");
}
seq_printf(m, "\n");
return 0;
}
static inline int expkey_match (struct cache_head *a, struct cache_head *b)
{
struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
struct svc_expkey *new = container_of(b, struct svc_expkey, h);
if (orig->ek_fsidtype != new->ek_fsidtype ||
orig->ek_client != new->ek_client ||
memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
return 0;
return 1;
}
static inline void expkey_init(struct cache_head *cnew,
struct cache_head *citem)
{
struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
kref_get(&item->ek_client->ref);
new->ek_client = item->ek_client;
new->ek_fsidtype = item->ek_fsidtype;
memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
}
static inline void expkey_update(struct cache_head *cnew,
struct cache_head *citem)
{
struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
new->ek_path = item->ek_path;
path_get(&item->ek_path);
}
static struct cache_head *expkey_alloc(void)
{
struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
if (i)
return &i->h;
else
return NULL;
}
static struct cache_detail svc_expkey_cache = {
.owner = THIS_MODULE,
.hash_size = EXPKEY_HASHMAX,
.hash_table = expkey_table,
.name = "nfsd.fh",
.cache_put = expkey_put,
.cache_upcall = expkey_upcall,
.cache_parse = expkey_parse,
.cache_show = expkey_show,
.match = expkey_match,
.init = expkey_init,
.update = expkey_update,
.alloc = expkey_alloc,
};
static int
svc_expkey_hash(struct svc_expkey *item)
{
int hash = item->ek_fsidtype;
char * cp = (char*)item->ek_fsid;
int len = key_len(item->ek_fsidtype);
hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
hash &= EXPKEY_HASHMASK;
return hash;
}
static struct svc_expkey *
svc_expkey_lookup(struct svc_expkey *item)
{
struct cache_head *ch;
int hash = svc_expkey_hash(item);
ch = sunrpc_cache_lookup(&svc_expkey_cache, &item->h,
hash);
if (ch)
return container_of(ch, struct svc_expkey, h);
else
return NULL;
}
static struct svc_expkey *
svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old)
{
struct cache_head *ch;
int hash = svc_expkey_hash(new);
ch = sunrpc_cache_update(&svc_expkey_cache, &new->h,
&old->h, hash);
if (ch)
return container_of(ch, struct svc_expkey, h);
else
return NULL;
}
#define EXPORT_HASHBITS 8
#define EXPORT_HASHMAX (1<< EXPORT_HASHBITS)
static struct cache_head *export_table[EXPORT_HASHMAX];
static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
{
int i;
for (i = 0; i < fsloc->locations_count; i++) {
kfree(fsloc->locations[i].path);
kfree(fsloc->locations[i].hosts);
}
kfree(fsloc->locations);
}
static void svc_export_put(struct kref *ref)
{
struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
path_put(&exp->ex_path);
auth_domain_put(exp->ex_client);
kfree(exp->ex_pathname);
nfsd4_fslocs_free(&exp->ex_fslocs);
kfree(exp);
}
static void svc_export_request(struct cache_detail *cd,
struct cache_head *h,
char **bpp, int *blen)
{
/* client path */
struct svc_export *exp = container_of(h, struct svc_export, h);
char *pth;
qword_add(bpp, blen, exp->ex_client->name);
pth = d_path(&exp->ex_path, *bpp, *blen);
if (IS_ERR(pth)) {
/* is this correct? */
(*bpp)[0] = '\n';
return;
}
qword_add(bpp, blen, pth);
(*bpp)[-1] = '\n';
}
static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
{
return sunrpc_cache_pipe_upcall(cd, h, svc_export_request);
}
static struct svc_export *svc_export_update(struct svc_export *new,
struct svc_export *old);
static struct svc_export *svc_export_lookup(struct svc_export *);
static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
{
/*
* We currently export only dirs, regular files, and (for v4
* pseudoroot) symlinks.
*/
if (!S_ISDIR(inode->i_mode) &&
!S_ISLNK(inode->i_mode) &&
!S_ISREG(inode->i_mode))
return -ENOTDIR;
/*
* Mountd should never pass down a writeable V4ROOT export, but,
* just to make sure:
*/
if (*flags & NFSEXP_V4ROOT)
*flags |= NFSEXP_READONLY;
/* There are two requirements on a filesystem to be exportable.
* 1: We must be able to identify the filesystem from a number.
* either a device number (so FS_REQUIRES_DEV needed)
* or an FSID number (so NFSEXP_FSID or ->uuid is needed).
* 2: We must be able to find an inode from a filehandle.
* This means that s_export_op must be set.
*/
if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
!(*flags & NFSEXP_FSID) &&
uuid == NULL) {
dprintk("exp_export: export of non-dev fs without fsid\n");
return -EINVAL;
}
if (!inode->i_sb->s_export_op ||
!inode->i_sb->s_export_op->fh_to_dentry) {
dprintk("exp_export: export of invalid fs type.\n");
return -EINVAL;
}
return 0;
}
#ifdef CONFIG_NFSD_V4
static int
fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
{
int len;
int migrated, i, err;
/* listsize */
err = get_int(mesg, &fsloc->locations_count);
if (err)
return err;
if (fsloc->locations_count > MAX_FS_LOCATIONS)
return -EINVAL;
if (fsloc->locations_count == 0)
return 0;
fsloc->locations = kzalloc(fsloc->locations_count
* sizeof(struct nfsd4_fs_location), GFP_KERNEL);
if (!fsloc->locations)
return -ENOMEM;
for (i=0; i < fsloc->locations_count; i++) {
/* colon separated host list */
err = -EINVAL;
len = qword_get(mesg, buf, PAGE_SIZE);
if (len <= 0)
goto out_free_all;
err = -ENOMEM;
fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
if (!fsloc->locations[i].hosts)
goto out_free_all;
err = -EINVAL;
/* slash separated path component list */
len = qword_get(mesg, buf, PAGE_SIZE);
if (len <= 0)
goto out_free_all;
err = -ENOMEM;
fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
if (!fsloc->locations[i].path)
goto out_free_all;
}
/* migrated */
err = get_int(mesg, &migrated);
if (err)
goto out_free_all;
err = -EINVAL;
if (migrated < 0 || migrated > 1)
goto out_free_all;
fsloc->migrated = migrated;
return 0;
out_free_all:
nfsd4_fslocs_free(fsloc);
return err;
}
static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
{
int listsize, err;
struct exp_flavor_info *f;
err = get_int(mesg, &listsize);
if (err)
return err;
if (listsize < 0 || listsize > MAX_SECINFO_LIST)
return -EINVAL;
for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
err = get_int(mesg, &f->pseudoflavor);
if (err)
return err;
/*
* XXX: It would be nice to also check whether this
* pseudoflavor is supported, so we can discover the
* problem at export time instead of when a client fails
* to authenticate.
*/
err = get_int(mesg, &f->flags);
if (err)
return err;
/* Only some flags are allowed to differ between flavors: */
if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
return -EINVAL;
}
exp->ex_nflavors = listsize;
return 0;
}
#else /* CONFIG_NFSD_V4 */
static inline int
fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
static inline int
secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
#endif
static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
{
/* client path expiry [flags anonuid anongid fsid] */
char *buf;
int len;
int err;
struct auth_domain *dom = NULL;
struct svc_export exp = {}, *expp;
int an_int;
if (mesg[mlen-1] != '\n')
return -EINVAL;
mesg[mlen-1] = 0;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* client */
err = -EINVAL;
len = qword_get(&mesg, buf, PAGE_SIZE);
if (len <= 0)
goto out;
err = -ENOENT;
dom = auth_domain_find(buf);
if (!dom)
goto out;
/* path */
err = -EINVAL;
if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
goto out1;
err = kern_path(buf, 0, &exp.ex_path);
if (err)
goto out1;
exp.ex_client = dom;
err = -ENOMEM;
exp.ex_pathname = kstrdup(buf, GFP_KERNEL);
if (!exp.ex_pathname)
goto out2;
/* expiry */
err = -EINVAL;
exp.h.expiry_time = get_expiry(&mesg);
if (exp.h.expiry_time == 0)
goto out3;
/* flags */
err = get_int(&mesg, &an_int);
if (err == -ENOENT) {
err = 0;
set_bit(CACHE_NEGATIVE, &exp.h.flags);
} else {
if (err || an_int < 0)
goto out3;
exp.ex_flags= an_int;
/* anon uid */
err = get_int(&mesg, &an_int);
if (err)
goto out3;
exp.ex_anon_uid= an_int;
/* anon gid */
err = get_int(&mesg, &an_int);
if (err)
goto out3;
exp.ex_anon_gid= an_int;
/* fsid */
err = get_int(&mesg, &an_int);
if (err)
goto out3;
exp.ex_fsid = an_int;
while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
if (strcmp(buf, "fsloc") == 0)
err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
else if (strcmp(buf, "uuid") == 0) {
/* expect a 16 byte uuid encoded as \xXXXX... */
len = qword_get(&mesg, buf, PAGE_SIZE);
if (len != 16)
err = -EINVAL;
else {
exp.ex_uuid =
kmemdup(buf, 16, GFP_KERNEL);
if (exp.ex_uuid == NULL)
err = -ENOMEM;
}
} else if (strcmp(buf, "secinfo") == 0)
err = secinfo_parse(&mesg, buf, &exp);
else
/* quietly ignore unknown words and anything
* following. Newer user-space can try to set
* new values, then see what the result was.
*/
break;
if (err)
goto out4;
}
err = check_export(exp.ex_path.dentry->d_inode, &exp.ex_flags,
exp.ex_uuid);
if (err)
goto out4;
}
expp = svc_export_lookup(&exp);
if (expp)
expp = svc_export_update(&exp, expp);
else
err = -ENOMEM;
cache_flush();
if (expp == NULL)
err = -ENOMEM;
else
exp_put(expp);
out4:
nfsd4_fslocs_free(&exp.ex_fslocs);
kfree(exp.ex_uuid);
out3:
kfree(exp.ex_pathname);
out2:
path_put(&exp.ex_path);
out1:
auth_domain_put(dom);
out:
kfree(buf);
return err;
}
static void exp_flags(struct seq_file *m, int flag, int fsid,
uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fslocs);
static void show_secinfo(struct seq_file *m, struct svc_export *exp);
static int svc_export_show(struct seq_file *m,
struct cache_detail *cd,
struct cache_head *h)
{
struct svc_export *exp ;
if (h ==NULL) {
seq_puts(m, "#path domain(flags)\n");
return 0;
}
exp = container_of(h, struct svc_export, h);
seq_path(m, &exp->ex_path, " \t\n\\");
seq_putc(m, '\t');
seq_escape(m, exp->ex_client->name, " \t\n\\");
seq_putc(m, '(');
if (test_bit(CACHE_VALID, &h->flags) &&
!test_bit(CACHE_NEGATIVE, &h->flags)) {
exp_flags(m, exp->ex_flags, exp->ex_fsid,
exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
if (exp->ex_uuid) {
int i;
seq_puts(m, ",uuid=");
for (i=0; i<16; i++) {
if ((i&3) == 0 && i)
seq_putc(m, ':');
seq_printf(m, "%02x", exp->ex_uuid[i]);
}
}
show_secinfo(m, exp);
}
seq_puts(m, ")\n");
return 0;
}
static int svc_export_match(struct cache_head *a, struct cache_head *b)
{
struct svc_export *orig = container_of(a, struct svc_export, h);
struct svc_export *new = container_of(b, struct svc_export, h);
return orig->ex_client == new->ex_client &&
orig->ex_path.dentry == new->ex_path.dentry &&
orig->ex_path.mnt == new->ex_path.mnt;
}
static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
{
struct svc_export *new = container_of(cnew, struct svc_export, h);
struct svc_export *item = container_of(citem, struct svc_export, h);
kref_get(&item->ex_client->ref);
new->ex_client = item->ex_client;
new->ex_path.dentry = dget(item->ex_path.dentry);
new->ex_path.mnt = mntget(item->ex_path.mnt);
new->ex_pathname = NULL;
new->ex_fslocs.locations = NULL;
new->ex_fslocs.locations_count = 0;
new->ex_fslocs.migrated = 0;
}
static void export_update(struct cache_head *cnew, struct cache_head *citem)
{
struct svc_export *new = container_of(cnew, struct svc_export, h);
struct svc_export *item = container_of(citem, struct svc_export, h);
int i;
new->ex_flags = item->ex_flags;
new->ex_anon_uid = item->ex_anon_uid;
new->ex_anon_gid = item->ex_anon_gid;
new->ex_fsid = item->ex_fsid;
new->ex_uuid = item->ex_uuid;
item->ex_uuid = NULL;
new->ex_pathname = item->ex_pathname;
item->ex_pathname = NULL;
new->ex_fslocs.locations = item->ex_fslocs.locations;
item->ex_fslocs.locations = NULL;
new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
item->ex_fslocs.locations_count = 0;
new->ex_fslocs.migrated = item->ex_fslocs.migrated;
item->ex_fslocs.migrated = 0;
new->ex_nflavors = item->ex_nflavors;
for (i = 0; i < MAX_SECINFO_LIST; i++) {
new->ex_flavors[i] = item->ex_flavors[i];
}
}
static struct cache_head *svc_export_alloc(void)
{
struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
if (i)
return &i->h;
else
return NULL;
}
struct cache_detail svc_export_cache = {
.owner = THIS_MODULE,
.hash_size = EXPORT_HASHMAX,
.hash_table = export_table,
.name = "nfsd.export",
.cache_put = svc_export_put,
.cache_upcall = svc_export_upcall,
.cache_parse = svc_export_parse,
.cache_show = svc_export_show,
.match = svc_export_match,
.init = svc_export_init,
.update = export_update,
.alloc = svc_export_alloc,
};
static int
svc_export_hash(struct svc_export *exp)
{
int hash;
hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
return hash;
}
static struct svc_export *
svc_export_lookup(struct svc_export *exp)
{
struct cache_head *ch;
int hash = svc_export_hash(exp);
ch = sunrpc_cache_lookup(&svc_export_cache, &exp->h,
hash);
if (ch)
return container_of(ch, struct svc_export, h);
else
return NULL;
}
static struct svc_export *
svc_export_update(struct svc_export *new, struct svc_export *old)
{
struct cache_head *ch;
int hash = svc_export_hash(old);
ch = sunrpc_cache_update(&svc_export_cache, &new->h,
&old->h,
hash);
if (ch)
return container_of(ch, struct svc_export, h);
else
return NULL;
}
static struct svc_expkey *
exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
{
struct svc_expkey key, *ek;
int err;
if (!clp)
return ERR_PTR(-ENOENT);
key.ek_client = clp;
key.ek_fsidtype = fsid_type;
memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
ek = svc_expkey_lookup(&key);
if (ek == NULL)
return ERR_PTR(-ENOMEM);
err = cache_check(&svc_expkey_cache, &ek->h, reqp);
if (err)
return ERR_PTR(err);
return ek;
}
#ifdef CONFIG_NFSD_DEPRECATED
static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
struct svc_export *exp)
{
struct svc_expkey key, *ek;
key.ek_client = clp;
key.ek_fsidtype = fsid_type;
memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
key.ek_path = exp->ex_path;
key.h.expiry_time = NEVER;
key.h.flags = 0;
ek = svc_expkey_lookup(&key);
if (ek)
ek = svc_expkey_update(&key,ek);
if (ek) {
cache_put(&ek->h, &svc_expkey_cache);
return 0;
}
return -ENOMEM;
}
/*
* Find the client's export entry matching xdev/xino.
*/
static inline struct svc_expkey *
exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
{
u32 fsidv[3];
if (old_valid_dev(dev)) {
mk_fsid(FSID_DEV, fsidv, dev, ino, 0, NULL);
return exp_find_key(clp, FSID_DEV, fsidv, NULL);
}
mk_fsid(FSID_ENCODE_DEV, fsidv, dev, ino, 0, NULL);
return exp_find_key(clp, FSID_ENCODE_DEV, fsidv, NULL);
}
/*
* Find the client's export entry matching fsid
*/
static inline struct svc_expkey *
exp_get_fsid_key(svc_client *clp, int fsid)
{
u32 fsidv[2];
mk_fsid(FSID_NUM, fsidv, 0, 0, fsid, NULL);
return exp_find_key(clp, FSID_NUM, fsidv, NULL);
}
#endif
static svc_export *exp_get_by_name(svc_client *clp, const struct path *path,
struct cache_req *reqp)
{
struct svc_export *exp, key;
int err;
if (!clp)
return ERR_PTR(-ENOENT);
key.ex_client = clp;
key.ex_path = *path;
exp = svc_export_lookup(&key);
if (exp == NULL)
return ERR_PTR(-ENOMEM);
err = cache_check(&svc_export_cache, &exp->h, reqp);
if (err)
return ERR_PTR(err);
return exp;
}
/*
* Find the export entry for a given dentry.
*/
static struct svc_export *exp_parent(svc_client *clp, struct path *path)
{
struct dentry *saved = dget(path->dentry);
svc_export *exp = exp_get_by_name(clp, path, NULL);
while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
struct dentry *parent = dget_parent(path->dentry);
dput(path->dentry);
path->dentry = parent;
exp = exp_get_by_name(clp, path, NULL);
}
dput(path->dentry);
path->dentry = saved;
return exp;
}
#ifdef CONFIG_NFSD_DEPRECATED
/*
* Hashtable locking. Write locks are placed only by user processes
* wanting to modify export information.
* Write locking only done in this file. Read locking
* needed externally.
*/
static DECLARE_RWSEM(hash_sem);
void
exp_readlock(void)
{
down_read(&hash_sem);
}
static inline void
exp_writelock(void)
{
down_write(&hash_sem);
}
void
exp_readunlock(void)
{
up_read(&hash_sem);
}
static inline void
exp_writeunlock(void)
{
up_write(&hash_sem);
}
#else
/* hash_sem not needed once deprecated interface is removed */
void exp_readlock(void) {}
static inline void exp_writelock(void){}
void exp_readunlock(void) {}
static inline void exp_writeunlock(void){}
#endif
#ifdef CONFIG_NFSD_DEPRECATED
static void exp_do_unexport(svc_export *unexp);
static int exp_verify_string(char *cp, int max);
static void exp_fsid_unhash(struct svc_export *exp)
{
struct svc_expkey *ek;
if ((exp->ex_flags & NFSEXP_FSID) == 0)
return;
ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
if (!IS_ERR(ek)) {
sunrpc_invalidate(&ek->h, &svc_expkey_cache);
cache_put(&ek->h, &svc_expkey_cache);
}
}
static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
{
u32 fsid[2];
if ((exp->ex_flags & NFSEXP_FSID) == 0)
return 0;
mk_fsid(FSID_NUM, fsid, 0, 0, exp->ex_fsid, NULL);
return exp_set_key(clp, FSID_NUM, fsid, exp);
}
static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
{
u32 fsid[2];
struct inode *inode = exp->ex_path.dentry->d_inode;
dev_t dev = inode->i_sb->s_dev;
if (old_valid_dev(dev)) {
mk_fsid(FSID_DEV, fsid, dev, inode->i_ino, 0, NULL);
return exp_set_key(clp, FSID_DEV, fsid, exp);
}
mk_fsid(FSID_ENCODE_DEV, fsid, dev, inode->i_ino, 0, NULL);
return exp_set_key(clp, FSID_ENCODE_DEV, fsid, exp);
}
static void exp_unhash(struct svc_export *exp)
{
struct svc_expkey *ek;
struct inode *inode = exp->ex_path.dentry->d_inode;
ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
if (!IS_ERR(ek)) {
sunrpc_invalidate(&ek->h, &svc_expkey_cache);
cache_put(&ek->h, &svc_expkey_cache);
}
}
/*
* Export a file system.
*/
int
exp_export(struct nfsctl_export *nxp)
{
svc_client *clp;
struct svc_export *exp = NULL;
struct svc_export new;
struct svc_expkey *fsid_key = NULL;
struct path path;
int err;
/* Consistency check */
err = -EINVAL;
if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
!exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
goto out;
dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
nxp->ex_client, nxp->ex_path,
(unsigned)nxp->ex_dev, (long)nxp->ex_ino,
nxp->ex_flags);
/* Try to lock the export table for update */
exp_writelock();
/* Look up client info */
if (!(clp = auth_domain_find(nxp->ex_client)))
goto out_unlock;
/* Look up the dentry */
err = kern_path(nxp->ex_path, 0, &path);
if (err)
goto out_put_clp;
err = -EINVAL;
exp = exp_get_by_name(clp, &path, NULL);
memset(&new, 0, sizeof(new));
/* must make sure there won't be an ex_fsid clash */
if ((nxp->ex_flags & NFSEXP_FSID) &&
(!IS_ERR(fsid_key = exp_get_fsid_key(clp, nxp->ex_dev))) &&
fsid_key->ek_path.mnt &&
(fsid_key->ek_path.mnt != path.mnt ||
fsid_key->ek_path.dentry != path.dentry))
goto finish;
if (!IS_ERR(exp)) {
/* just a flags/id/fsid update */
exp_fsid_unhash(exp);
exp->ex_flags = nxp->ex_flags;
exp->ex_anon_uid = nxp->ex_anon_uid;
exp->ex_anon_gid = nxp->ex_anon_gid;
exp->ex_fsid = nxp->ex_dev;
err = exp_fsid_hash(clp, exp);
goto finish;
}
err = check_export(path.dentry->d_inode, &nxp->ex_flags, NULL);
if (err) goto finish;
err = -ENOMEM;
dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
new.h.expiry_time = NEVER;
new.h.flags = 0;
new.ex_pathname = kstrdup(nxp->ex_path, GFP_KERNEL);
if (!new.ex_pathname)
goto finish;
new.ex_client = clp;
new.ex_path = path;
new.ex_flags = nxp->ex_flags;
new.ex_anon_uid = nxp->ex_anon_uid;
new.ex_anon_gid = nxp->ex_anon_gid;
new.ex_fsid = nxp->ex_dev;
exp = svc_export_lookup(&new);
if (exp)
exp = svc_export_update(&new, exp);
if (!exp)
goto finish;
if (exp_hash(clp, exp) ||
exp_fsid_hash(clp, exp)) {
/* failed to create at least one index */
exp_do_unexport(exp);
cache_flush();
} else
err = 0;
finish:
kfree(new.ex_pathname);
if (!IS_ERR_OR_NULL(exp))
exp_put(exp);
if (!IS_ERR_OR_NULL(fsid_key))
cache_put(&fsid_key->h, &svc_expkey_cache);
path_put(&path);
out_put_clp:
auth_domain_put(clp);
out_unlock:
exp_writeunlock();
out:
return err;
}
/*
* Unexport a file system. The export entry has already
* been removed from the client's list of exported fs's.
*/
static void
exp_do_unexport(svc_export *unexp)
{
sunrpc_invalidate(&unexp->h, &svc_export_cache);
exp_unhash(unexp);
exp_fsid_unhash(unexp);
}
/*
* unexport syscall.
*/
int
exp_unexport(struct nfsctl_export *nxp)
{
struct auth_domain *dom;
svc_export *exp;
struct path path;
int err;
/* Consistency check */
if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
!exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
return -EINVAL;
exp_writelock();
err = -EINVAL;
dom = auth_domain_find(nxp->ex_client);
if (!dom) {
dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
goto out_unlock;
}
err = kern_path(nxp->ex_path, 0, &path);
if (err)
goto out_domain;
err = -EINVAL;
exp = exp_get_by_name(dom, &path, NULL);
path_put(&path);
if (IS_ERR(exp))
goto out_domain;
exp_do_unexport(exp);
exp_put(exp);
err = 0;
out_domain:
auth_domain_put(dom);
cache_flush();
out_unlock:
exp_writeunlock();
return err;
}
#endif /* CONFIG_NFSD_DEPRECATED */
/*
* Obtain the root fh on behalf of a client.
* This could be done in user space, but I feel that it adds some safety
* since its harder to fool a kernel module than a user space program.
*/
int
exp_rootfh(svc_client *clp, char *name, struct knfsd_fh *f, int maxsize)
{
struct svc_export *exp;
struct path path;
struct inode *inode;
struct svc_fh fh;
int err;
err = -EPERM;
/* NB: we probably ought to check that it's NUL-terminated */
if (kern_path(name, 0, &path)) {
printk("nfsd: exp_rootfh path not found %s", name);
return err;
}
inode = path.dentry->d_inode;
dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
name, path.dentry, clp->name,
inode->i_sb->s_id, inode->i_ino);
exp = exp_parent(clp, &path);
if (IS_ERR(exp)) {
err = PTR_ERR(exp);
goto out;
}
/*
* fh must be initialized before calling fh_compose
*/
fh_init(&fh, maxsize);
if (fh_compose(&fh, exp, path.dentry, NULL))
err = -EINVAL;
else
err = 0;
memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
fh_put(&fh);
exp_put(exp);
out:
path_put(&path);
return err;
}
static struct svc_export *exp_find(struct auth_domain *clp, int fsid_type,
u32 *fsidv, struct cache_req *reqp)
{
struct svc_export *exp;
struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);
if (IS_ERR(ek))
return ERR_CAST(ek);
exp = exp_get_by_name(clp, &ek->ek_path, reqp);
cache_put(&ek->h, &svc_expkey_cache);
if (IS_ERR(exp))
return ERR_CAST(exp);
return exp;
}
__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
{
struct exp_flavor_info *f;
struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
/* legacy gss-only clients are always OK: */
if (exp->ex_client == rqstp->rq_gssclient)
return 0;
/* ip-address based client; check sec= export option: */
for (f = exp->ex_flavors; f < end; f++) {
if (f->pseudoflavor == rqstp->rq_flavor)
return 0;
}
/* defaults in absence of sec= options: */
if (exp->ex_nflavors == 0) {
if (rqstp->rq_flavor == RPC_AUTH_NULL ||
rqstp->rq_flavor == RPC_AUTH_UNIX)
return 0;
}
return nfserr_wrongsec;
}
/*
* Uses rq_client and rq_gssclient to find an export; uses rq_client (an
* auth_unix client) if it's available and has secinfo information;
* otherwise, will try to use rq_gssclient.
*
* Called from functions that handle requests; functions that do work on
* behalf of mountd are passed a single client name to use, and should
* use exp_get_by_name() or exp_find().
*/
struct svc_export *
rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
{
struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
if (rqstp->rq_client == NULL)
goto gss;
/* First try the auth_unix client: */
exp = exp_get_by_name(rqstp->rq_client, path, &rqstp->rq_chandle);
if (PTR_ERR(exp) == -ENOENT)
goto gss;
if (IS_ERR(exp))
return exp;
/* If it has secinfo, assume there are no gss/... clients */
if (exp->ex_nflavors > 0)
return exp;
gss:
/* Otherwise, try falling back on gss client */
if (rqstp->rq_gssclient == NULL)
return exp;
gssexp = exp_get_by_name(rqstp->rq_gssclient, path, &rqstp->rq_chandle);
if (PTR_ERR(gssexp) == -ENOENT)
return exp;
if (!IS_ERR(exp))
exp_put(exp);
return gssexp;
}
struct svc_export *
rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
{
struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
if (rqstp->rq_client == NULL)
goto gss;
/* First try the auth_unix client: */
exp = exp_find(rqstp->rq_client, fsid_type, fsidv, &rqstp->rq_chandle);
if (PTR_ERR(exp) == -ENOENT)
goto gss;
if (IS_ERR(exp))
return exp;
/* If it has secinfo, assume there are no gss/... clients */
if (exp->ex_nflavors > 0)
return exp;
gss:
/* Otherwise, try falling back on gss client */
if (rqstp->rq_gssclient == NULL)
return exp;
gssexp = exp_find(rqstp->rq_gssclient, fsid_type, fsidv,
&rqstp->rq_chandle);
if (PTR_ERR(gssexp) == -ENOENT)
return exp;
if (!IS_ERR(exp))
exp_put(exp);
return gssexp;
}
struct svc_export *
rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
{
struct dentry *saved = dget(path->dentry);
struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
struct dentry *parent = dget_parent(path->dentry);
dput(path->dentry);
path->dentry = parent;
exp = rqst_exp_get_by_name(rqstp, path);
}
dput(path->dentry);
path->dentry = saved;
return exp;
}
static struct svc_export *find_fsidzero_export(struct svc_rqst *rqstp)
{
u32 fsidv[2];
mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
return rqst_exp_find(rqstp, FSID_NUM, fsidv);
}
/*
* Called when we need the filehandle for the root of the pseudofs,
* for a given NFSv4 client. The root is defined to be the
* export point with fsid==0
*/
__be32
exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
{
struct svc_export *exp;
__be32 rv;
exp = find_fsidzero_export(rqstp);
if (IS_ERR(exp))
return nfserrno(PTR_ERR(exp));
rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
exp_put(exp);
return rv;
}
/* Iterator */
static void *e_start(struct seq_file *m, loff_t *pos)
__acquires(svc_export_cache.hash_lock)
{
loff_t n = *pos;
unsigned hash, export;
struct cache_head *ch;
exp_readlock();
read_lock(&svc_export_cache.hash_lock);
if (!n--)
return SEQ_START_TOKEN;
hash = n >> 32;
export = n & ((1LL<<32) - 1);
for (ch=export_table[hash]; ch; ch=ch->next)
if (!export--)
return ch;
n &= ~((1LL<<32) - 1);
do {
hash++;
n += 1LL<<32;
} while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
if (hash >= EXPORT_HASHMAX)
return NULL;
*pos = n+1;
return export_table[hash];
}
static void *e_next(struct seq_file *m, void *p, loff_t *pos)
{
struct cache_head *ch = p;
int hash = (*pos >> 32);
if (p == SEQ_START_TOKEN)
hash = 0;
else if (ch->next == NULL) {
hash++;
*pos += 1LL<<32;
} else {
++*pos;
return ch->next;
}
*pos &= ~((1LL<<32) - 1);
while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
hash++;
*pos += 1LL<<32;
}
if (hash >= EXPORT_HASHMAX)
return NULL;
++*pos;
return export_table[hash];
}
static void e_stop(struct seq_file *m, void *p)
__releases(svc_export_cache.hash_lock)
{
read_unlock(&svc_export_cache.hash_lock);
exp_readunlock();
}
static struct flags {
int flag;
char *name[2];
} expflags[] = {
{ NFSEXP_READONLY, {"ro", "rw"}},
{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
{ NFSEXP_ASYNC, {"async", "sync"}},
{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
{ NFSEXP_NOHIDE, {"nohide", ""}},
{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
{ NFSEXP_V4ROOT, {"v4root", ""}},
{ 0, {"", ""}}
};
static void show_expflags(struct seq_file *m, int flags, int mask)
{
struct flags *flg;
int state, first = 0;
for (flg = expflags; flg->flag; flg++) {
if (flg->flag & ~mask)
continue;
state = (flg->flag & flags) ? 0 : 1;
if (*flg->name[state])
seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
}
}
static void show_secinfo_flags(struct seq_file *m, int flags)
{
seq_printf(m, ",");
show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
}
static bool secinfo_flags_equal(int f, int g)
{
f &= NFSEXP_SECINFO_FLAGS;
g &= NFSEXP_SECINFO_FLAGS;
return f == g;
}
static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
{
int flags;
flags = (*fp)->flags;
seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
(*fp)++;
while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
seq_printf(m, ":%d", (*fp)->pseudoflavor);
(*fp)++;
}
return flags;
}
static void show_secinfo(struct seq_file *m, struct svc_export *exp)
{
struct exp_flavor_info *f;
struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
int flags;
if (exp->ex_nflavors == 0)
return;
f = exp->ex_flavors;
flags = show_secinfo_run(m, &f, end);
if (!secinfo_flags_equal(flags, exp->ex_flags))
show_secinfo_flags(m, flags);
while (f != end) {
flags = show_secinfo_run(m, &f, end);
show_secinfo_flags(m, flags);
}
}
static void exp_flags(struct seq_file *m, int flag, int fsid,
uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fsloc)
{
show_expflags(m, flag, NFSEXP_ALLFLAGS);
if (flag & NFSEXP_FSID)
seq_printf(m, ",fsid=%d", fsid);
if (anonu != (uid_t)-2 && anonu != (0x10000-2))
seq_printf(m, ",anonuid=%u", anonu);
if (anong != (gid_t)-2 && anong != (0x10000-2))
seq_printf(m, ",anongid=%u", anong);
if (fsloc && fsloc->locations_count > 0) {
char *loctype = (fsloc->migrated) ? "refer" : "replicas";
int i;
seq_printf(m, ",%s=", loctype);
seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
seq_putc(m, '@');
seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
for (i = 1; i < fsloc->locations_count; i++) {
seq_putc(m, ';');
seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
seq_putc(m, '@');
seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
}
}
}
static int e_show(struct seq_file *m, void *p)
{
struct cache_head *cp = p;
struct svc_export *exp = container_of(cp, struct svc_export, h);
if (p == SEQ_START_TOKEN) {
seq_puts(m, "# Version 1.1\n");
seq_puts(m, "# Path Client(Flags) # IPs\n");
return 0;
}
cache_get(&exp->h);
if (cache_check(&svc_export_cache, &exp->h, NULL))
return 0;
cache_put(&exp->h, &svc_export_cache);
return svc_export_show(m, &svc_export_cache, cp);
}
const struct seq_operations nfs_exports_op = {
.start = e_start,
.next = e_next,
.stop = e_stop,
.show = e_show,
};
#ifdef CONFIG_NFSD_DEPRECATED
/*
* Add or modify a client.
* Change requests may involve the list of host addresses. The list of
* exports and possibly existing uid maps are left untouched.
*/
int
exp_addclient(struct nfsctl_client *ncp)
{
struct auth_domain *dom;
int i, err;
struct in6_addr addr6;
/* First, consistency check. */
err = -EINVAL;
if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
goto out;
if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
goto out;
/* Lock the hashtable */
exp_writelock();
dom = unix_domain_find(ncp->cl_ident);
err = -ENOMEM;
if (!dom)
goto out_unlock;
/* Insert client into hashtable. */
for (i = 0; i < ncp->cl_naddr; i++) {
ipv6_addr_set_v4mapped(ncp->cl_addrlist[i].s_addr, &addr6);
auth_unix_add_addr(&init_net, &addr6, dom);
}
auth_unix_forget_old(dom);
auth_domain_put(dom);
err = 0;
out_unlock:
exp_writeunlock();
out:
return err;
}
/*
* Delete a client given an identifier.
*/
int
exp_delclient(struct nfsctl_client *ncp)
{
int err;
struct auth_domain *dom;
err = -EINVAL;
if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
goto out;
/* Lock the hashtable */
exp_writelock();
dom = auth_domain_find(ncp->cl_ident);
/* just make sure that no addresses work
* and that it will expire soon
*/
if (dom) {
err = auth_unix_forget_old(dom);
auth_domain_put(dom);
}
exp_writeunlock();
out:
return err;
}
/*
* Verify that string is non-empty and does not exceed max length.
*/
static int
exp_verify_string(char *cp, int max)
{
int i;
for (i = 0; i < max; i++)
if (!cp[i])
return i;
cp[i] = 0;
printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
return 0;
}
#endif /* CONFIG_NFSD_DEPRECATED */
/*
* Initialize the exports module.
*/
int
nfsd_export_init(void)
{
int rv;
dprintk("nfsd: initializing export module.\n");
rv = cache_register(&svc_export_cache);
if (rv)
return rv;
rv = cache_register(&svc_expkey_cache);
if (rv)
cache_unregister(&svc_export_cache);
return rv;
}
/*
* Flush exports table - called when last nfsd thread is killed
*/
void
nfsd_export_flush(void)
{
exp_writelock();
cache_purge(&svc_expkey_cache);
cache_purge(&svc_export_cache);
exp_writeunlock();
}
/*
* Shutdown the exports module.
*/
void
nfsd_export_shutdown(void)
{
dprintk("nfsd: shutting down export module.\n");
exp_writelock();
cache_unregister(&svc_expkey_cache);
cache_unregister(&svc_export_cache);
svcauth_unix_purge();
exp_writeunlock();
dprintk("nfsd: export shutdown complete.\n");
}