Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1435 insertions, 0 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
new file mode 100644
index 0000000000..11a0eaa2f9
--- /dev/null
+++ b/fs/nfsd/export.c
@@ -0,0 +1,1435 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/sunrpc/svc_xprt.h>
+
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_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 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_rcu(key, ek_rcu);
+}
+
+static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall(cd, h);
+}
+
+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 struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+					    struct svc_expkey *old);
+static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
+
+static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client fsidtype fsid expiry [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 (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 (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;
+	err = get_expiry(&mesg, &key.h.expiry_time);
+	if (err)
+		goto out;
+
+	key.ek_client = dom;
+	key.ek_fsidtype = fsidtype;
+	memcpy(key.ek_fsid, buf, len);
+
+	ek = svc_expkey_lookup(cd, &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(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, NULL);
+		else
+			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(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, buf);
+		else
+			err = -ENOMEM;
+		path_put(&key.ek_path);
+	}
+	cache_flush();
+ out:
+	if (ek)
+		cache_put(&ek->h, cd);
+	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 void expkey_flush(void)
+{
+	/*
+	 * Take the nfsd_mutex here to ensure that the file cache is not
+	 * destroyed while we're in the middle of flushing.
+	 */
+	mutex_lock(&nfsd_mutex);
+	nfsd_file_cache_purge(current->nsproxy->net_ns);
+	mutex_unlock(&nfsd_mutex);
+}
+
+static const struct cache_detail svc_expkey_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPKEY_HASHMAX,
+	.name		= "nfsd.fh",
+	.cache_put	= expkey_put,
+	.cache_upcall	= expkey_upcall,
+	.cache_request	= expkey_request,
+	.cache_parse	= expkey_parse,
+	.cache_show	= expkey_show,
+	.match		= expkey_match,
+	.init		= expkey_init,
+	.update       	= expkey_update,
+	.alloc		= expkey_alloc,
+	.flush		= expkey_flush,
+};
+
+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 cache_detail *cd, struct svc_expkey *item)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(item);
+
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_expkey, h);
+	else
+		return NULL;
+}
+
+static struct svc_expkey *
+svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+		  struct svc_expkey *old)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(new);
+
+	ch = sunrpc_cache_update(cd, &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 void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
+{
+	struct nfsd4_fs_location *locations = fsloc->locations;
+	int i;
+
+	if (!locations)
+		return;
+
+	for (i = 0; i < fsloc->locations_count; i++) {
+		kfree(locations[i].path);
+		kfree(locations[i].hosts);
+	}
+
+	kfree(locations);
+	fsloc->locations = NULL;
+}
+
+static int export_stats_init(struct export_stats *stats)
+{
+	stats->start_time = ktime_get_seconds();
+	return nfsd_percpu_counters_init(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
+static void export_stats_reset(struct export_stats *stats)
+{
+	nfsd_percpu_counters_reset(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
+static void export_stats_destroy(struct export_stats *stats)
+{
+	nfsd_percpu_counters_destroy(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
+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);
+	nfsd4_fslocs_free(&exp->ex_fslocs);
+	export_stats_destroy(&exp->ex_stats);
+	kfree(exp->ex_uuid);
+	kfree_rcu(exp, ex_rcu);
+}
+
+static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall(cd, h);
+}
+
+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 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 path *path, int *flags, unsigned char *uuid)
+{
+	struct inode *inode = d_inode(path->dentry);
+
+	/*
+	 * 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.
+	 * 3: We must not currently be on an idmapped mount.
+	 */
+	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;
+	}
+
+	if (is_idmapped_mnt(path->mnt)) {
+		dprintk("exp_export: export of idmapped mounts not yet supported.\n");
+		return -EINVAL;
+	}
+
+	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
+	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
+		dprintk("%s: %s does not support subtree checking!\n",
+			__func__, inode->i_sb->s_type->name);
+		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;
+
+	/* more than one fsloc */
+	if (fsloc->locations)
+		return -EINVAL;
+
+	/* listsize */
+	err = get_uint(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 = kcalloc(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)
+{
+	struct exp_flavor_info *f;
+	u32 listsize;
+	int err;
+
+	/* more than one secinfo */
+	if (exp->ex_nflavors)
+		return -EINVAL;
+
+	err = get_uint(mesg, &listsize);
+	if (err)
+		return err;
+	if (listsize > MAX_SECINFO_LIST)
+		return -EINVAL;
+
+	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
+		err = get_uint(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_uint(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 xprtsec_parse(char **mesg, char *buf, struct svc_export *exp)
+{
+	unsigned int i, mode, listsize;
+	int err;
+
+	err = get_uint(mesg, &listsize);
+	if (err)
+		return err;
+	if (listsize > NFSEXP_XPRTSEC_NUM)
+		return -EINVAL;
+
+	exp->ex_xprtsec_modes = 0;
+	for (i = 0; i < listsize; i++) {
+		err = get_uint(mesg, &mode);
+		if (err)
+			return err;
+		if (mode > NFSEXP_XPRTSEC_MTLS)
+			return -EINVAL;
+		exp->ex_xprtsec_modes |= mode;
+	}
+	return 0;
+}
+
+static inline int
+nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
+{
+	int len;
+
+	/* more than one uuid */
+	if (*puuid)
+		return -EINVAL;
+
+	/* expect a 16 byte uuid encoded as \xXXXX... */
+	len = qword_get(mesg, buf, PAGE_SIZE);
+	if (len != EX_UUID_LEN)
+		return -EINVAL;
+
+	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
+	if (*puuid == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client path expiry [flags anonuid anongid fsid] */
+	char *buf;
+	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;
+	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
+		goto out;
+
+	err = -ENOENT;
+	dom = auth_domain_find(buf);
+	if (!dom)
+		goto out;
+
+	/* path */
+	err = -EINVAL;
+	if (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;
+	exp.cd = cd;
+	exp.ex_devid_map = NULL;
+	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
+
+	/* expiry */
+	err = get_expiry(&mesg, &exp.h.expiry_time);
+	if (err)
+		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= make_kuid(current_user_ns(), an_int);
+
+		/* anon gid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
+
+		/* fsid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_fsid = an_int;
+
+		while (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)
+				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
+			else if (strcmp(buf, "secinfo") == 0)
+				err = secinfo_parse(&mesg, buf, &exp);
+			else if (strcmp(buf, "xprtsec") == 0)
+				err = xprtsec_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, &exp.ex_flags, exp.ex_uuid);
+		if (err)
+			goto out4;
+
+		/*
+		 * No point caching this if it would immediately expire.
+		 * Also, this protects exportfs's dummy export from the
+		 * anon_uid/anon_gid checks:
+		 */
+		if (exp.h.expiry_time < seconds_since_boot())
+			goto out4;
+		/*
+		 * For some reason exportfs has been passing down an
+		 * invalid (-1) uid & gid on the "dummy" export which it
+		 * uses to test export support.  To make sure exportfs
+		 * sees errors from check_export we therefore need to
+		 * delay these checks till after check_export:
+		 */
+		err = -EINVAL;
+		if (!uid_valid(exp.ex_anon_uid))
+			goto out4;
+		if (!gid_valid(exp.ex_anon_gid))
+			goto out4;
+		err = 0;
+
+		nfsd4_setup_layout_type(&exp);
+	}
+
+	expp = svc_export_lookup(&exp);
+	if (!expp) {
+		err = -ENOMEM;
+		goto out4;
+	}
+	expp = svc_export_update(&exp, expp);
+	if (expp) {
+		trace_nfsd_export_update(expp);
+		cache_flush();
+		exp_put(expp);
+	} else
+		err = -ENOMEM;
+out4:
+	nfsd4_fslocs_free(&exp.ex_fslocs);
+	kfree(exp.ex_uuid);
+out3:
+	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,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
+static void show_secinfo(struct seq_file *m, struct svc_export *exp);
+
+static int is_export_stats_file(struct seq_file *m)
+{
+	/*
+	 * The export_stats file uses the same ops as the exports file.
+	 * We use the file's name to determine the reported info per export.
+	 * There is no rename in nsfdfs, so d_name.name is stable.
+	 */
+	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
+}
+
+static int svc_export_show(struct seq_file *m,
+			   struct cache_detail *cd,
+			   struct cache_head *h)
+{
+	struct svc_export *exp;
+	bool export_stats = is_export_stats_file(m);
+
+	if (h == NULL) {
+		if (export_stats)
+			seq_puts(m, "#path domain start-time\n#\tstats\n");
+		else
+			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\\");
+	if (export_stats) {
+		seq_printf(m, "\t%lld\n", exp->ex_stats.start_time);
+		seq_printf(m, "\tfh_stale: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_FH_STALE]));
+		seq_printf(m, "\tio_read: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_READ]));
+		seq_printf(m, "\tio_write: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_WRITE]));
+		seq_putc(m, '\n');
+		return 0;
+	}
+	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 < EX_UUID_LEN; 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 &&
+		path_equal(&orig->ex_path, &new->ex_path);
+}
+
+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 = item->ex_path;
+	path_get(&item->ex_path);
+	new->ex_fslocs.locations = NULL;
+	new->ex_fslocs.locations_count = 0;
+	new->ex_fslocs.migrated = 0;
+	new->ex_layout_types = 0;
+	new->ex_uuid = NULL;
+	new->cd = item->cd;
+	export_stats_reset(&new->ex_stats);
+}
+
+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_devid_map = item->ex_devid_map;
+	item->ex_devid_map = NULL;
+	new->ex_uuid = item->ex_uuid;
+	item->ex_uuid = 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_layout_types = item->ex_layout_types;
+	new->ex_nflavors = item->ex_nflavors;
+	for (i = 0; i < MAX_SECINFO_LIST; i++) {
+		new->ex_flavors[i] = item->ex_flavors[i];
+	}
+	new->ex_xprtsec_modes = item->ex_xprtsec_modes;
+}
+
+static struct cache_head *svc_export_alloc(void)
+{
+	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
+	if (!i)
+		return NULL;
+
+	if (export_stats_init(&i->ex_stats)) {
+		kfree(i);
+		return NULL;
+	}
+
+	return &i->h;
+}
+
+static const struct cache_detail svc_export_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPORT_HASHMAX,
+	.name		= "nfsd.export",
+	.cache_put	= svc_export_put,
+	.cache_upcall	= svc_export_upcall,
+	.cache_request	= svc_export_request,
+	.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_rcu(exp->cd, &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(old->cd, &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(struct cache_detail *cd, struct auth_domain *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(cd, &key);
+	if (ek == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &ek->h, reqp);
+	if (err) {
+		trace_nfsd_exp_find_key(&key, err);
+		return ERR_PTR(err);
+	}
+	return ek;
+}
+
+static struct svc_export *
+exp_get_by_name(struct cache_detail *cd, struct auth_domain *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;
+	key.cd = cd;
+
+	exp = svc_export_lookup(&key);
+	if (exp == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &exp->h, reqp);
+	if (err) {
+		trace_nfsd_exp_get_by_name(&key, err);
+		return ERR_PTR(err);
+	}
+	return exp;
+}
+
+/*
+ * Find the export entry for a given dentry.
+ */
+static struct svc_export *
+exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
+{
+	struct dentry *saved = dget(path->dentry);
+	struct svc_export *exp = exp_get_by_name(cd, 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(cd, clp, path, NULL);
+	}
+	dput(path->dentry);
+	path->dentry = saved;
+	return exp;
+}
+
+
+
+/*
+ * 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(struct net *net, struct auth_domain *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;
+	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
+	struct cache_detail	*cd = nn->svc_export_cache;
+
+	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 = d_inode(path.dentry);
+
+	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(cd, 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 cache_detail *cd,
+				   struct auth_domain *clp, int fsid_type,
+				   u32 *fsidv, struct cache_req *reqp)
+{
+	struct svc_export *exp;
+	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
+	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
+	if (IS_ERR(ek))
+		return ERR_CAST(ek);
+
+	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
+	cache_put(&ek->h, nn->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, *end = exp->ex_flavors + exp->ex_nflavors;
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
+		if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
+			goto ok;
+	}
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
+		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
+		    !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
+			goto ok;
+	}
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
+		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
+		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
+			goto ok;
+	}
+	goto denied;
+
+ok:
+	/* 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_cred.cr_flavor)
+			return 0;
+	}
+	/* defaults in absence of sec= options: */
+	if (exp->ex_nflavors == 0) {
+		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
+		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
+			return 0;
+	}
+
+	/* If the compound op contains a spo_must_allowed op,
+	 * it will be sent with integrity/protection which
+	 * will have to be expressly allowed on mounts that
+	 * don't support it
+	 */
+
+	if (nfsd4_spo_must_allow(rqstp))
+		return 0;
+
+denied:
+	return rqstp->rq_vers < 4 ? nfserr_acces : 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);
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (rqstp->rq_client == NULL)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_get_by_name(cd, 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(cd, 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);
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (rqstp->rq_client == NULL)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_find(cd, 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(cd, 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;
+}
+
+struct svc_export *rqst_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 = rqst_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;
+}
+
+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_NOREADDIRPLUS, {"nordirplus", ""}},
+	{ NFSEXP_NOHIDE, {"nohide", ""}},
+	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
+	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
+	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
+	{ NFSEXP_V4ROOT, {"v4root", ""}},
+	{ NFSEXP_PNFS, {"pnfs", ""}},
+	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
+	{ 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,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
+{
+	struct user_namespace *userns = m->file->f_cred->user_ns;
+
+	show_expflags(m, flag, NFSEXP_ALLFLAGS);
+	if (flag & NFSEXP_FSID)
+		seq_printf(m, ",fsid=%d", fsid);
+	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
+	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
+		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
+	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
+	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
+		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, 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);
+	struct cache_detail *cd = m->private;
+	bool export_stats = is_export_stats_file(m);
+
+	if (p == SEQ_START_TOKEN) {
+		seq_puts(m, "# Version 1.1\n");
+		if (export_stats)
+			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
+		else
+			seq_puts(m, "# Path Client(Flags) # IPs\n");
+		return 0;
+	}
+
+	exp_get(exp);
+	if (cache_check(cd, &exp->h, NULL))
+		return 0;
+	exp_put(exp);
+	return svc_export_show(m, cd, cp);
+}
+
+const struct seq_operations nfs_exports_op = {
+	.start	= cache_seq_start_rcu,
+	.next	= cache_seq_next_rcu,
+	.stop	= cache_seq_stop_rcu,
+	.show	= e_show,
+};
+
+/*
+ * Initialize the exports module.
+ */
+int
+nfsd_export_init(struct net *net)
+{
+	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
+
+	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
+	if (IS_ERR(nn->svc_export_cache))
+		return PTR_ERR(nn->svc_export_cache);
+	rv = cache_register_net(nn->svc_export_cache, net);
+	if (rv)
+		goto destroy_export_cache;
+
+	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
+	if (IS_ERR(nn->svc_expkey_cache)) {
+		rv = PTR_ERR(nn->svc_expkey_cache);
+		goto unregister_export_cache;
+	}
+	rv = cache_register_net(nn->svc_expkey_cache, net);
+	if (rv)
+		goto destroy_expkey_cache;
+	return 0;
+
+destroy_expkey_cache:
+	cache_destroy_net(nn->svc_expkey_cache, net);
+unregister_export_cache:
+	cache_unregister_net(nn->svc_export_cache, net);
+destroy_export_cache:
+	cache_destroy_net(nn->svc_export_cache, net);
+	return rv;
+}
+
+/*
+ * Flush exports table - called when last nfsd thread is killed
+ */
+void
+nfsd_export_flush(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_purge(nn->svc_expkey_cache);
+	cache_purge(nn->svc_export_cache);
+}
+
+/*
+ * Shutdown the exports module.
+ */
+void
+nfsd_export_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
+
+	cache_unregister_net(nn->svc_expkey_cache, net);
+	cache_unregister_net(nn->svc_export_cache, net);
+	cache_destroy_net(nn->svc_expkey_cache, net);
+	cache_destroy_net(nn->svc_export_cache, net);
+	svcauth_unix_purge(net);
+
+	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
+}