linux/fs/nfsd/export.c
Josh Triplett 896440d560 [PATCH] nfsd: add lock annotations to e_start and e_stop
e_start acquires svc_export_cache.hash_lock, and e_stop releases it.  Add
lock annotations to these two functions so that sparse can check callers
for lock pairing, and so that sparse will not complain about these
functions since they intentionally use locks in this manner.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:18 -07:00

1337 lines
30 KiB
C

#define MSNFS /* HACK HACK */
/*
* linux/fs/nfsd/export.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/unistd.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/in.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/rwsem.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/hash.h>
#include <linux/module.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/nfsfh.h>
#include <linux/nfsd/syscall.h>
#include <linux/lockd/bind.h>
#define NFSDDBG_FACILITY NFSDDBG_EXPORT
#define NFSD_PARANOIA 1
typedef struct auth_domain svc_client;
typedef struct svc_export svc_export;
static void exp_do_unexport(svc_export *unexp);
static int exp_verify_string(char *cp, int max);
/*
* 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)) {
dput(key->ek_dentry);
mntput(key->ek_mnt);
}
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 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;
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;
if ((len=qword_get(&mesg, buf, PAGE_SIZE)) < 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)
cache_put(&ek->h, &svc_expkey_cache);
else err = -ENOMEM;
} else {
struct nameidata nd;
err = path_lookup(buf, 0, &nd);
if (err)
goto out;
dprintk("Found the path %s\n", buf);
key.ek_mnt = nd.mnt;
key.ek_dentry = nd.dentry;
ek = svc_expkey_update(&key, ek);
if (ek)
cache_put(&ek->h, &svc_expkey_cache);
else
err = -ENOMEM;
path_release(&nd);
}
cache_flush();
out:
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 ;
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%08x", ek->ek_client->name,
ek->ek_fsidtype, ek->ek_fsid[0]);
if (ek->ek_fsidtype != 1)
seq_printf(m, "%08x", ek->ek_fsid[1]);
if (ek->ek_fsidtype == 2)
seq_printf(m, "%08x", ek->ek_fsid[2]);
if (test_bit(CACHE_VALID, &h->flags) &&
!test_bit(CACHE_NEGATIVE, &h->flags)) {
seq_printf(m, " ");
seq_path(m, ek->ek_mnt, ek->ek_dentry, "\\ \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;
new->ek_fsid[0] = item->ek_fsid[0];
new->ek_fsid[1] = item->ek_fsid[1];
new->ek_fsid[2] = item->ek_fsid[2];
}
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_mnt = mntget(item->ek_mnt);
new->ek_dentry = dget(item->ek_dentry);
}
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_request = expkey_request,
.cache_parse = expkey_parse,
.cache_show = expkey_show,
.match = expkey_match,
.init = expkey_init,
.update = expkey_update,
.alloc = expkey_alloc,
};
static struct svc_expkey *
svc_expkey_lookup(struct svc_expkey *item)
{
struct cache_head *ch;
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;
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 = new->ek_fsidtype;
char * cp = (char*)new->ek_fsid;
int len = key_len(new->ek_fsidtype);
hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
hash ^= hash_ptr(new->ek_client, EXPKEY_HASHBITS);
hash &= EXPKEY_HASHMASK;
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)
#define EXPORT_HASHMASK (EXPORT_HASHMAX -1)
static struct cache_head *export_table[EXPORT_HASHMAX];
static void svc_export_put(struct kref *ref)
{
struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
dput(exp->ex_dentry);
mntput(exp->ex_mnt);
auth_domain_put(exp->ex_client);
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_dentry, exp->ex_mnt, *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 inode *inode, int flags)
{
/* We currently export only dirs and regular files.
* This is what umountd does.
*/
if (!S_ISDIR(inode->i_mode) &&
!S_ISREG(inode->i_mode))
return -ENOTDIR;
/* 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 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)) {
dprintk("exp_export: export of non-dev fs without fsid\n");
return -EINVAL;
}
if (!inode->i_sb->s_export_op) {
dprintk("exp_export: export of invalid fs type.\n");
return -EINVAL;
}
/* Ok, we can export it */;
if (!inode->i_sb->s_export_op->find_exported_dentry)
inode->i_sb->s_export_op->find_exported_dentry =
find_exported_dentry;
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 len;
int err;
struct auth_domain *dom = NULL;
struct nameidata nd;
struct svc_export exp, *expp;
int an_int;
nd.dentry = NULL;
if (mesg[mlen-1] != '\n')
return -EINVAL;
mesg[mlen-1] = 0;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
err = -ENOMEM;
if (!buf) goto out;
/* client */
len = qword_get(&mesg, buf, PAGE_SIZE);
err = -EINVAL;
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 out;
err = path_lookup(buf, 0, &nd);
if (err) goto out_no_path;
exp.h.flags = 0;
exp.ex_client = dom;
exp.ex_mnt = nd.mnt;
exp.ex_dentry = nd.dentry;
/* expiry */
err = -EINVAL;
exp.h.expiry_time = get_expiry(&mesg);
if (exp.h.expiry_time == 0)
goto out;
/* flags */
err = get_int(&mesg, &an_int);
if (err == -ENOENT)
set_bit(CACHE_NEGATIVE, &exp.h.flags);
else {
if (err || an_int < 0) goto out;
exp.ex_flags= an_int;
/* anon uid */
err = get_int(&mesg, &an_int);
if (err) goto out;
exp.ex_anon_uid= an_int;
/* anon gid */
err = get_int(&mesg, &an_int);
if (err) goto out;
exp.ex_anon_gid= an_int;
/* fsid */
err = get_int(&mesg, &an_int);
if (err) goto out;
exp.ex_fsid = an_int;
err = check_export(nd.dentry->d_inode, exp.ex_flags);
if (err) goto out;
}
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);
out:
if (nd.dentry)
path_release(&nd);
out_no_path:
if (dom)
auth_domain_put(dom);
kfree(buf);
return err;
}
static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong);
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_mnt, exp->ex_dentry, " \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);
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_dentry == new->ex_dentry &&
orig->ex_mnt == new->ex_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_dentry = dget(item->ex_dentry);
new->ex_mnt = mntget(item->ex_mnt);
}
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);
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;
}
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_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 struct svc_export *
svc_export_lookup(struct svc_export *exp)
{
struct cache_head *ch;
int hash;
hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
hash ^= hash_ptr(exp->ex_dentry, EXPORT_HASHBITS);
hash ^= hash_ptr(exp->ex_mnt, EXPORT_HASHBITS);
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;
hash = hash_ptr(old->ex_client, EXPORT_HASHBITS);
hash ^= hash_ptr(old->ex_dentry, EXPORT_HASHBITS);
hash ^= hash_ptr(old->ex_mnt, EXPORT_HASHBITS);
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 NULL;
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)
if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
ek = ERR_PTR(err);
return ek;
}
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_mnt = exp->ex_mnt;
key.ek_dentry = exp->ex_dentry;
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_v0(fsidv, dev, ino);
return exp_find_key(clp, 0, fsidv, NULL);
}
mk_fsid_v3(fsidv, dev, ino);
return exp_find_key(clp, 3, 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_v1(fsidv, fsid);
return exp_find_key(clp, 1, fsidv, NULL);
}
svc_export *
exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
struct cache_req *reqp)
{
struct svc_export *exp, key;
if (!clp)
return NULL;
key.ex_client = clp;
key.ex_mnt = mnt;
key.ex_dentry = dentry;
exp = svc_export_lookup(&key);
if (exp != NULL)
switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
case 0: break;
case -EAGAIN:
exp = ERR_PTR(-EAGAIN);
break;
default:
exp = NULL;
}
return exp;
}
/*
* Find the export entry for a given dentry.
*/
struct svc_export *
exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
struct cache_req *reqp)
{
svc_export *exp;
dget(dentry);
exp = exp_get_by_name(clp, mnt, dentry, reqp);
while (exp == NULL && !IS_ROOT(dentry)) {
struct dentry *parent;
parent = dget_parent(dentry);
dput(dentry);
dentry = parent;
exp = exp_get_by_name(clp, mnt, dentry, reqp);
}
dput(dentry);
return exp;
}
/*
* 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);
}
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 (ek && !IS_ERR(ek)) {
ek->h.expiry_time = get_seconds()-1;
cache_put(&ek->h, &svc_expkey_cache);
}
svc_expkey_cache.nextcheck = get_seconds();
}
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_v1(fsid, exp->ex_fsid);
return exp_set_key(clp, 1, fsid, exp);
}
static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
{
u32 fsid[2];
struct inode *inode = exp->ex_dentry->d_inode;
dev_t dev = inode->i_sb->s_dev;
if (old_valid_dev(dev)) {
mk_fsid_v0(fsid, dev, inode->i_ino);
return exp_set_key(clp, 0, fsid, exp);
}
mk_fsid_v3(fsid, dev, inode->i_ino);
return exp_set_key(clp, 3, fsid, exp);
}
static void exp_unhash(struct svc_export *exp)
{
struct svc_expkey *ek;
struct inode *inode = exp->ex_dentry->d_inode;
ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
if (ek && !IS_ERR(ek)) {
ek->h.expiry_time = get_seconds()-1;
cache_put(&ek->h, &svc_expkey_cache);
}
svc_expkey_cache.nextcheck = get_seconds();
}
/*
* 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 nameidata nd;
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 = path_lookup(nxp->ex_path, 0, &nd);
if (err)
goto out_unlock;
err = -EINVAL;
exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
/* must make sure there won't be an ex_fsid clash */
if ((nxp->ex_flags & NFSEXP_FSID) &&
(fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
!IS_ERR(fsid_key) &&
fsid_key->ek_mnt &&
(fsid_key->ek_mnt != nd.mnt || fsid_key->ek_dentry != nd.dentry) )
goto finish;
if (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(nd.dentry->d_inode, nxp->ex_flags);
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_client = clp;
new.ex_mnt = nd.mnt;
new.ex_dentry = nd.dentry;
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();
err = -ENOMEM;
}
finish:
if (exp)
exp_put(exp);
if (fsid_key && !IS_ERR(fsid_key))
cache_put(&fsid_key->h, &svc_expkey_cache);
if (clp)
auth_domain_put(clp);
path_release(&nd);
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)
{
unexp->h.expiry_time = get_seconds()-1;
svc_export_cache.nextcheck = get_seconds();
exp_unhash(unexp);
exp_fsid_unhash(unexp);
}
/*
* unexport syscall.
*/
int
exp_unexport(struct nfsctl_export *nxp)
{
struct auth_domain *dom;
svc_export *exp;
struct nameidata nd;
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 = path_lookup(nxp->ex_path, 0, &nd);
if (err)
goto out_domain;
err = -EINVAL;
exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
path_release(&nd);
if (!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;
}
/*
* 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 *path, struct knfsd_fh *f, int maxsize)
{
struct svc_export *exp;
struct nameidata nd;
struct inode *inode;
struct svc_fh fh;
int err;
err = -EPERM;
/* NB: we probably ought to check that it's NUL-terminated */
if (path_lookup(path, 0, &nd)) {
printk("nfsd: exp_rootfh path not found %s", path);
return err;
}
inode = nd.dentry->d_inode;
dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
path, nd.dentry, clp->name,
inode->i_sb->s_id, inode->i_ino);
exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
if (!exp) {
dprintk("nfsd: exp_rootfh export not found.\n");
goto out;
}
/*
* fh must be initialized before calling fh_compose
*/
fh_init(&fh, maxsize);
if (fh_compose(&fh, exp, nd.dentry, NULL))
err = -EINVAL;
else
err = 0;
memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
fh_put(&fh);
exp_put(exp);
out:
path_release(&nd);
return err;
}
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 (!ek || IS_ERR(ek))
return ERR_PTR(PTR_ERR(ek));
exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp);
cache_put(&ek->h, &svc_expkey_cache);
if (!exp || IS_ERR(exp))
return ERR_PTR(PTR_ERR(exp));
return exp;
}
/*
* 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
*/
int
exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
struct cache_req *creq)
{
struct svc_expkey *fsid_key;
struct svc_export *exp;
int rv;
u32 fsidv[2];
mk_fsid_v1(fsidv, 0);
fsid_key = exp_find_key(clp, 1, fsidv, creq);
if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
return nfserr_dropit;
if (!fsid_key || IS_ERR(fsid_key))
return nfserr_perm;
exp = exp_get_by_name(clp, fsid_key->ek_mnt, fsid_key->ek_dentry, creq);
if (exp == NULL)
rv = nfserr_perm;
else if (IS_ERR(exp))
rv = nfserrno(PTR_ERR(exp));
else {
rv = fh_compose(fhp, exp,
fsid_key->ek_dentry, NULL);
exp_put(exp);
}
cache_put(&fsid_key->h, &svc_expkey_cache);
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", ""}},
#ifdef MSNFS
{ NFSEXP_MSNFS, {"msnfs", ""}},
#endif
{ 0, {"", ""}}
};
static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
{
int first = 0;
struct flags *flg;
for (flg = expflags; flg->flag; flg++) {
int state = (flg->flag & flag)?0:1;
if (*flg->name[state])
seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
}
if (flag & NFSEXP_FSID)
seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
if (anonu != (uid_t)-2 && anonu != (0x10000-2))
seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
if (anong != (gid_t)-2 && anong != (0x10000-2))
seq_printf(m, "%sanongid=%d", first++?",":"", anong);
}
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);
}
struct seq_operations nfs_exports_op = {
.start = e_start,
.next = e_next,
.stop = e_stop,
.show = e_show,
};
/*
* 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;
/* 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++)
auth_unix_add_addr(ncp->cl_addrlist[i], 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;
}
/*
* Initialize the exports module.
*/
void
nfsd_export_init(void)
{
dprintk("nfsd: initializing export module.\n");
cache_register(&svc_export_cache);
cache_register(&svc_expkey_cache);
}
/*
* 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();
if (cache_unregister(&svc_expkey_cache))
printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
if (cache_unregister(&svc_export_cache))
printk(KERN_ERR "nfsd: failed to unregister export cache\n");
svcauth_unix_purge();
exp_writeunlock();
dprintk("nfsd: export shutdown complete.\n");
}