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Merge branch 'mnt_devname' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

Browse source 
* 'mnt_devname' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  vfs: bury ->get_sb()
  nfs: switch NFS from ->get_sb() to ->mount()
  nfs: stop mangling ->mnt_devname on NFS
  vfs: new superblock methods to override /proc/*/mount{s,info}
  nfs: nfs_do_{ref,sub}mount() superblock argument is redundant
  nfs: make nfs_path() work without vfsmount
  nfs: store devname at disconnected NFS roots
  nfs: propagate devname to nfs{,4}_get_root()
This commit is contained in:
Linus Torvalds 2011-03-16 19:09:57 -07:00
commit 054cfaacf8
13 changed files with 316 additions and 272 deletions
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6
Documentation/filesystems/Locking
View file

@ -166,13 +166,11 @@ prototypes:
void (*kill_sb) (struct super_block *);
locking rules:
may block
get_sb yes
mount yes
kill_sb yes
->get_sb() returns error or 0 with locked superblock attached to the vfsmount
(exclusive on ->s_umount).
->mount() returns ERR_PTR or the root dentry.
->mount() returns ERR_PTR or the root dentry; its superblock should be locked
on return.
->kill_sb() takes a write-locked superblock, does all shutdown work on it,
unlocks and drops the reference.

7
Documentation/filesystems/porting
View file

@ -394,3 +394,10 @@ file) you must return -EOPNOTSUPP if FALLOC_FL_PUNCH_HOLE is set in mode.
Currently you can only have FALLOC_FL_PUNCH_HOLE with FALLOC_FL_KEEP_SIZE set,
so the i_size should not change when hole punching, even when puching the end of
a file off.
--
[mandatory]
->get_sb() is gone. Switch to use of ->mount(). Typically it's just
a matter of switching from calling get_sb_... to mount_... and changing the
function type. If you were doing it manually, just switch from setting ->mnt_root
to some pointer to returning that pointer. On errors return ERR_PTR(...).

56
Documentation/filesystems/vfs.txt
View file

@ -95,10 +95,11 @@ functions:
extern int unregister_filesystem(struct file_system_type *);
The passed struct file_system_type describes your filesystem. When a
request is made to mount a device onto a directory in your filespace,
the VFS will call the appropriate get_sb() method for the specific
filesystem. The dentry for the mount point will then be updated to
point to the root inode for the new filesystem.
request is made to mount a filesystem onto a directory in your namespace,
the VFS will call the appropriate mount() method for the specific
filesystem. New vfsmount refering to the tree returned by ->mount()
will be attached to the mountpoint, so that when pathname resolution
reaches the mountpoint it will jump into the root of that vfsmount.
You can see all filesystems that are registered to the kernel in the
file /proc/filesystems.
@ -107,14 +108,14 @@ file /proc/filesystems.
struct file_system_type
-----------------------
This describes the filesystem. As of kernel 2.6.22, the following
This describes the filesystem. As of kernel 2.6.39, the following
members are defined:
struct file_system_type {
const char *name;
int fs_flags;
int (*get_sb) (struct file_system_type *, int,
const char *, void *, struct vfsmount *);
struct dentry (*mount) (struct file_system_type *, int,
const char *, void *);
void (*kill_sb) (struct super_block *);
struct module *owner;
struct file_system_type * next;
@ -128,11 +129,11 @@ struct file_system_type {
fs_flags: various flags (i.e. FS_REQUIRES_DEV, FS_NO_DCACHE, etc.)
get_sb: the method to call when a new instance of this
mount: the method to call when a new instance of this
filesystem should be mounted
kill_sb: the method to call when an instance of this filesystem
should be unmounted
should be shut down
owner: for internal VFS use: you should initialize this to THIS_MODULE in
most cases.
@ -141,7 +142,7 @@ struct file_system_type {
s_lock_key, s_umount_key: lockdep-specific
The get_sb() method has the following arguments:
The mount() method has the following arguments:
struct file_system_type *fs_type: describes the filesystem, partly initialized
by the specific filesystem code
@ -153,32 +154,39 @@ The get_sb() method has the following arguments:
void *data: arbitrary mount options, usually comes as an ASCII
string (see "Mount Options" section)
struct vfsmount *mnt: a vfs-internal representation of a mount point
The mount() method must return the root dentry of the tree requested by
caller. An active reference to its superblock must be grabbed and the
superblock must be locked. On failure it should return ERR_PTR(error).
The get_sb() method must determine if the block device specified
in the dev_name and fs_type contains a filesystem of the type the method
supports. If it succeeds in opening the named block device, it initializes a
struct super_block descriptor for the filesystem contained by the block device.
On failure it returns an error.
The arguments match those of mount(2) and their interpretation
depends on filesystem type. E.g. for block filesystems, dev_name is
interpreted as block device name, that device is opened and if it
contains a suitable filesystem image the method creates and initializes
struct super_block accordingly, returning its root dentry to caller.
->mount() may choose to return a subtree of existing filesystem - it
doesn't have to create a new one. The main result from the caller's
point of view is a reference to dentry at the root of (sub)tree to
be attached; creation of new superblock is a common side effect.
The most interesting member of the superblock structure that the
get_sb() method fills in is the "s_op" field. This is a pointer to
mount() method fills in is the "s_op" field. This is a pointer to
a "struct super_operations" which describes the next level of the
filesystem implementation.
Usually, a filesystem uses one of the generic get_sb() implementations
and provides a fill_super() method instead. The generic methods are:
Usually, a filesystem uses one of the generic mount() implementations
and provides a fill_super() callback instead. The generic variants are:
get_sb_bdev: mount a filesystem residing on a block device
mount_bdev: mount a filesystem residing on a block device
get_sb_nodev: mount a filesystem that is not backed by a device
mount_nodev: mount a filesystem that is not backed by a device
get_sb_single: mount a filesystem which shares the instance between
mount_single: mount a filesystem which shares the instance between
all mounts
A fill_super() method implementation has the following arguments:
A fill_super() callback implementation has the following arguments:
struct super_block *sb: the superblock structure. The method fill_super()
struct super_block *sb: the superblock structure. The callback
must initialize this properly.
void *data: arbitrary mount options, usually comes as an ASCII

39
fs/namespace.c
View file

@ -978,7 +978,13 @@ static int show_vfsmnt(struct seq_file *m, void *v)
int err = 0;
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
if (mnt->mnt_sb->s_op->show_devname) {
err = mnt->mnt_sb->s_op->show_devname(m, mnt);
if (err)
goto out;
} else {
mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
}
seq_putc(m, ' ');
seq_path(m, &mnt_path, " \t\n\\");
seq_putc(m, ' ');
@ -1025,7 +1031,12 @@ static int show_mountinfo(struct seq_file *m, void *v)
seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, mnt->mnt_parent->mnt_id,
MAJOR(sb->s_dev), MINOR(sb->s_dev));
seq_dentry(m, mnt->mnt_root, " \t\n\\");
if (sb->s_op->show_path)
err = sb->s_op->show_path(m, mnt);
else
seq_dentry(m, mnt->mnt_root, " \t\n\\");
if (err)
goto out;
seq_putc(m, ' ');
seq_path_root(m, &mnt_path, &root, " \t\n\\");
if (root.mnt != p->root.mnt || root.dentry != p->root.dentry) {
@ -1060,7 +1071,12 @@ static int show_mountinfo(struct seq_file *m, void *v)
seq_puts(m, " - ");
show_type(m, sb);
seq_putc(m, ' ');
mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
if (sb->s_op->show_devname)
err = sb->s_op->show_devname(m, mnt);
else
mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
if (err)
goto out;
seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
err = show_sb_opts(m, sb);
if (err)
@ -1086,11 +1102,15 @@ static int show_vfsstat(struct seq_file *m, void *v)
int err = 0;
/* device */
if (mnt->mnt_devname) {
seq_puts(m, "device ");
mangle(m, mnt->mnt_devname);
} else
seq_puts(m, "no device");
if (mnt->mnt_sb->s_op->show_devname) {
err = mnt->mnt_sb->s_op->show_devname(m, mnt);
} else {
if (mnt->mnt_devname) {
seq_puts(m, "device ");
mangle(m, mnt->mnt_devname);
} else
seq_puts(m, "no device");
}
/* mount point */
seq_puts(m, " mounted on ");
@ -1104,7 +1124,8 @@ static int show_vfsstat(struct seq_file *m, void *v)
/* optional statistics */
if (mnt->mnt_sb->s_op->show_stats) {
seq_putc(m, ' ');
err = mnt->mnt_sb->s_op->show_stats(m, mnt);
if (!err)
err = mnt->mnt_sb->s_op->show_stats(m, mnt);
}
seq_putc(m, '\n');

13
fs/nfs/dir.c
View file

@ -1169,11 +1169,23 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
iput(inode);
}
static void nfs_d_release(struct dentry *dentry)
{
/* free cached devname value, if it survived that far */
if (unlikely(dentry->d_fsdata)) {
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
WARN_ON(1);
else
kfree(dentry->d_fsdata);
}
}
const struct dentry_operations nfs_dentry_operations = {
.d_revalidate = nfs_lookup_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
.d_release = nfs_d_release,
};
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
@ -1248,6 +1260,7 @@ const struct dentry_operations nfs4_dentry_operations = {
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
.d_release = nfs_d_release,
};
/*

42
fs/nfs/getroot.c
View file

@ -75,18 +75,25 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
/*
* get an NFS2/NFS3 root dentry from the root filehandle
*/
struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
const char *devname)
{
struct nfs_server *server = NFS_SB(sb);
struct nfs_fsinfo fsinfo;
struct dentry *ret;
struct inode *inode;
void *name = kstrdup(devname, GFP_KERNEL);
int error;
if (!name)
return ERR_PTR(-ENOMEM);
/* get the actual root for this mount */
fsinfo.fattr = nfs_alloc_fattr();
if (fsinfo.fattr == NULL)
if (fsinfo.fattr == NULL) {
kfree(name);
return ERR_PTR(-ENOMEM);
}
error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
if (error < 0) {
@ -119,7 +126,15 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
}
security_d_instantiate(ret, inode);
spin_lock(&ret->d_lock);
if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
ret->d_fsdata = name;
name = NULL;
}
spin_unlock(&ret->d_lock);
out:
if (name)
kfree(name);
nfs_free_fattr(fsinfo.fattr);
return ret;
}
@ -169,27 +184,35 @@ out:
/*
* get an NFS4 root dentry from the root filehandle
*/
struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh,
const char *devname)
{
struct nfs_server *server = NFS_SB(sb);
struct nfs_fattr *fattr = NULL;
struct dentry *ret;
struct inode *inode;
void *name = kstrdup(devname, GFP_KERNEL);
int error;
dprintk("--> nfs4_get_root()\n");
if (!name)
return ERR_PTR(-ENOMEM);
/* get the info about the server and filesystem */
error = nfs4_server_capabilities(server, mntfh);
if (error < 0) {
dprintk("nfs_get_root: getcaps error = %d\n",
-error);
kfree(name);
return ERR_PTR(error);
}
fattr = nfs_alloc_fattr();
if (fattr == NULL)
return ERR_PTR(-ENOMEM);;
if (fattr == NULL) {
kfree(name);
return ERR_PTR(-ENOMEM);
}
/* get the actual root for this mount */
error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
@ -223,8 +246,15 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
}
security_d_instantiate(ret, inode);
spin_lock(&ret->d_lock);
if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
ret->d_fsdata = name;
name = NULL;
}
spin_unlock(&ret->d_lock);
out:
if (name)
kfree(name);
nfs_free_fattr(fattr);
dprintk("<-- nfs4_get_root()\n");
return ret;

21
fs/nfs/internal.h
View file

@ -163,10 +163,10 @@ static inline void nfs_fs_proc_exit(void)
/* nfs4namespace.c */
#ifdef CONFIG_NFS_V4
extern struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry);
extern struct vfsmount *nfs_do_refmount(struct dentry *dentry);
#else
static inline
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
struct vfsmount *nfs_do_refmount(struct dentry *dentry)
{
return ERR_PTR(-ENOENT);
}
@ -247,16 +247,16 @@ extern void nfs_sb_active(struct super_block *sb);
extern void nfs_sb_deactive(struct super_block *sb);
/* namespace.c */
extern char *nfs_path(const char *base,
const struct dentry *droot,
const struct dentry *dentry,
extern char *nfs_path(char **p, struct dentry *dentry,
char *buffer, ssize_t buflen);
extern struct vfsmount *nfs_d_automount(struct path *path);
/* getroot.c */
extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);
extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
const char *);
#ifdef CONFIG_NFS_V4
extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *);
extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
const char *);
extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
#endif
@ -288,12 +288,11 @@ extern int _nfs4_call_sync_session(struct nfs_server *server,
/*
* Determine the device name as a string
*/
static inline char *nfs_devname(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
static inline char *nfs_devname(struct dentry *dentry,
char *buffer, ssize_t buflen)
{
return nfs_path(mnt_parent->mnt_devname, mnt_parent->mnt_root,
dentry, buffer, buflen);
char *dummy;
return nfs_path(&dummy, dentry, buffer, buflen);
}
/*

66
fs/nfs/namespace.c
View file

@ -25,33 +25,30 @@ static LIST_HEAD(nfs_automount_list);
static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
int nfs_mountpoint_expiry_timeout = 500 * HZ;
static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
static struct vfsmount *nfs_do_submount(struct dentry *dentry,
struct nfs_fh *fh,
struct nfs_fattr *fattr);
/*
* nfs_path - reconstruct the path given an arbitrary dentry
* @base - arbitrary string to prepend to the path
* @droot - pointer to root dentry for mountpoint
* @base - used to return pointer to the end of devname part of path
* @dentry - pointer to dentry
* @buffer - result buffer
* @buflen - length of buffer
*
* Helper function for constructing the path from the
* root dentry to an arbitrary hashed dentry.
* Helper function for constructing the server pathname
* by arbitrary hashed dentry.
*
* This is mainly for use in figuring out the path on the
* server side when automounting on top of an existing partition.
* server side when automounting on top of an existing partition
* and in generating /proc/mounts and friends.
*/
char *nfs_path(const char *base,
const struct dentry *droot,
const struct dentry *dentry,
char *buffer, ssize_t buflen)
char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen)
{
char *end;
int namelen;
unsigned seq;
const char *base;
rename_retry:
end = buffer+buflen;
@ -60,7 +57,10 @@ rename_retry:
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
while (!IS_ROOT(dentry) && dentry != droot) {
while (1) {
spin_lock(&dentry->d_lock);
if (IS_ROOT(dentry))
break;
namelen = dentry->d_name.len;
buflen -= namelen + 1;
if (buflen < 0)
@ -68,27 +68,47 @@ rename_retry:
end -= namelen;
memcpy(end, dentry->d_name.name, namelen);
*--end = '/';
spin_unlock(&dentry->d_lock);
dentry = dentry->d_parent;
}
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
if (read_seqretry(&rename_lock, seq)) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
goto rename_retry;
}
if (*end != '/') {
if (--buflen < 0)
if (--buflen < 0) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
goto Elong;
}
*--end = '/';
}
*p = end;
base = dentry->d_fsdata;
if (!base) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
WARN_ON(1);
return end;
}
namelen = strlen(base);
/* Strip off excess slashes in base string */
while (namelen > 0 && base[namelen - 1] == '/')
namelen--;
buflen -= namelen;
if (buflen < 0)
if (buflen < 0) {
spin_lock(&dentry->d_lock);
rcu_read_unlock();
goto Elong;
}
end -= namelen;
memcpy(end, base, namelen);
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
return end;
Elong_unlock:
spin_lock(&dentry->d_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
@ -143,9 +163,9 @@ struct vfsmount *nfs_d_automount(struct path *path)
}
if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
mnt = nfs_do_refmount(path->mnt, path->dentry);
mnt = nfs_do_refmount(path->dentry);
else
mnt = nfs_do_submount(path->mnt, path->dentry, fh, fattr);
mnt = nfs_do_submount(path->dentry, fh, fattr);
if (IS_ERR(mnt))
goto out;
@ -209,19 +229,17 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
/**
* nfs_do_submount - set up mountpoint when crossing a filesystem boundary
* @mnt_parent - mountpoint of parent directory
* @dentry - parent directory
* @fh - filehandle for new root dentry
* @fattr - attributes for new root inode
*
*/
static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
static struct vfsmount *nfs_do_submount(struct dentry *dentry,
struct nfs_fh *fh,
struct nfs_fattr *fattr)
{
struct nfs_clone_mount mountdata = {
.sb = mnt_parent->mnt_sb,
.sb = dentry->d_sb,
.dentry = dentry,
.fh = fh,
.fattr = fattr,
@ -237,11 +255,11 @@ static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
dentry->d_name.name);
if (page == NULL)
goto out;
devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
devname = nfs_devname(dentry, page, PAGE_SIZE);
mnt = (struct vfsmount *)devname;
if (IS_ERR(devname))
goto free_page;
mnt = nfs_do_clone_mount(NFS_SB(mnt_parent->mnt_sb), devname, &mountdata);
mnt = nfs_do_clone_mount(NFS_SB(dentry->d_sb), devname, &mountdata);
free_page:
free_page((unsigned long)page);
out:

41
fs/nfs/nfs4namespace.c
View file

@ -54,33 +54,29 @@ Elong:
/*
* Determine the mount path as a string
*/
static char *nfs4_path(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
char *buffer, ssize_t buflen)
static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
{
const char *srvpath;
srvpath = strchr(mnt_parent->mnt_devname, ':');
if (srvpath)
srvpath++;
else
srvpath = mnt_parent->mnt_devname;
return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
char *limit;
char *path = nfs_path(&limit, dentry, buffer, buflen);
if (!IS_ERR(path)) {
char *colon = strchr(path, ':');
if (colon && colon < limit)
path = colon + 1;
}
return path;
}
/*
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
* believe to be the server path to this dentry
*/
static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
static int nfs4_validate_fspath(struct dentry *dentry,
const struct nfs4_fs_locations *locations,
char *page, char *page2)
{
const char *path, *fs_path;
path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
path = nfs4_path(dentry, page, PAGE_SIZE);
if (IS_ERR(path))
return PTR_ERR(path);
@ -165,20 +161,18 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
/**
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error
* @mnt_parent - mountpoint of parent directory
* @dentry - parent directory
* @locations - array of NFSv4 server location information
*
*/
static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
const struct nfs4_fs_locations *locations)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
struct nfs_clone_mount mountdata = {
.sb = mnt_parent->mnt_sb,
.sb = dentry->d_sb,
.dentry = dentry,
.authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
.authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
};
char *page = NULL, *page2 = NULL;
int loc, error;
@ -198,7 +192,7 @@ static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
goto out;
/* Ensure fs path is a prefix of current dentry path */
error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
error = nfs4_validate_fspath(dentry, locations, page, page2);
if (error < 0) {
mnt = ERR_PTR(error);
goto out;
@ -225,11 +219,10 @@ out:
/*
* nfs_do_refmount - handle crossing a referral on server
* @mnt_parent - mountpoint of referral
* @dentry - dentry of referral
*
*/
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
struct vfsmount *nfs_do_refmount(struct dentry *dentry)
{
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct dentry *parent;
@ -262,7 +255,7 @@ struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentr
fs_locations->fs_path.ncomponents <= 0)
goto out_free;
mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
mnt = nfs_follow_referral(dentry, fs_locations);
out_free:
__free_page(page);
kfree(fs_locations);

194
fs/nfs/super.c
View file

@ -263,8 +263,11 @@ static match_table_t nfs_local_lock_tokens = {
static void nfs_umount_begin(struct super_block *);
static int nfs_statfs(struct dentry *, struct kstatfs *);
static int nfs_show_options(struct seq_file *, struct vfsmount *);
static int nfs_show_devname(struct seq_file *, struct vfsmount *);
static int nfs_show_path(struct seq_file *, struct vfsmount *);
static int nfs_show_stats(struct seq_file *, struct vfsmount *);
static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
static struct dentry *nfs_fs_mount(struct file_system_type *,
int, const char *, void *);
static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static void nfs_put_super(struct super_block *);
@ -274,7 +277,7 @@ static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
static struct file_system_type nfs_fs_type = {
.owner = THIS_MODULE,
.name = "nfs",
.get_sb = nfs_get_sb,
.mount = nfs_fs_mount,
.kill_sb = nfs_kill_super,
.fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
@ -296,6 +299,8 @@ static const struct super_operations nfs_sops = {
.evict_inode = nfs_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_devname = nfs_show_devname,
.show_path = nfs_show_path,
.show_stats = nfs_show_stats,
.remount_fs = nfs_remount,
};
@ -303,16 +308,16 @@ static const struct super_operations nfs_sops = {
#ifdef CONFIG_NFS_V4
static int nfs4_validate_text_mount_data(void *options,
struct nfs_parsed_mount_data *args, const char *dev_name);
static int nfs4_try_mount(int flags, const char *dev_name,
struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
static int nfs4_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
struct nfs_parsed_mount_data *data);
static struct dentry *nfs4_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static int nfs4_referral_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data);
static void nfs4_kill_super(struct super_block *sb);
@ -320,7 +325,7 @@ static void nfs4_kill_super(struct super_block *sb);
static struct file_system_type nfs4_fs_type = {
.owner = THIS_MODULE,
.name = "nfs4",
.get_sb = nfs4_get_sb,
.mount = nfs4_mount,
.kill_sb = nfs4_kill_super,
.fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
@ -352,7 +357,7 @@ static struct file_system_type nfs4_remote_referral_fs_type = {
struct file_system_type nfs4_referral_fs_type = {
.owner = THIS_MODULE,
.name = "nfs4",
.get_sb = nfs4_referral_get_sb,
.mount = nfs4_referral_mount,
.kill_sb = nfs4_kill_super,
.fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
@ -366,6 +371,8 @@ static const struct super_operations nfs4_sops = {
.evict_inode = nfs4_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_devname = nfs_show_devname,
.show_path = nfs_show_path,
.show_stats = nfs_show_stats,
.remount_fs = nfs_remount,
};
@ -726,6 +733,28 @@ static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
return 0;
}
static int nfs_show_devname(struct seq_file *m, struct vfsmount *mnt)
{
char *page = (char *) __get_free_page(GFP_KERNEL);
char *devname, *dummy;
int err = 0;
if (!page)
return -ENOMEM;
devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE);
if (IS_ERR(devname))
err = PTR_ERR(devname);
else
seq_escape(m, devname, " \t\n\\");
free_page((unsigned long)page);
return err;
}
static int nfs_show_path(struct seq_file *m, struct vfsmount *mnt)
{
seq_puts(m, "/");
return 0;
}
/*
* Present statistical information for this VFS mountpoint
*/
@ -2267,19 +2296,19 @@ static int nfs_bdi_register(struct nfs_server *server)
return bdi_register_dev(&server->backing_dev_info, server->s_dev);
}
static int nfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data)
{
struct nfs_server *server = NULL;
struct super_block *s;
struct nfs_parsed_mount_data *data;
struct nfs_fh *mntfh;
struct dentry *mntroot;
struct dentry *mntroot = ERR_PTR(-ENOMEM);
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
struct nfs_sb_mountdata sb_mntdata = {
.mntflags = flags,
};
int error = -ENOMEM;
int error;
data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
mntfh = nfs_alloc_fhandle();
@ -2290,12 +2319,14 @@ static int nfs_get_sb(struct file_system_type *fs_type,
/* Validate the mount data */
error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
if (error < 0)
if (error < 0) {
mntroot = ERR_PTR(error);
goto out;
}
#ifdef CONFIG_NFS_V4
if (data->version == 4) {
error = nfs4_try_mount(flags, dev_name, data, mnt);
mntroot = nfs4_try_mount(flags, dev_name, data);
kfree(data->client_address);
kfree(data->nfs_server.export_path);
goto out;
@ -2305,7 +2336,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
/* Get a volume representation */
server = nfs_create_server(data, mntfh);
if (IS_ERR(server)) {
error = PTR_ERR(server);
mntroot = ERR_CAST(server);
goto out;
}
sb_mntdata.server = server;
@ -2316,7 +2347,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
/* Get a superblock - note that we may end up sharing one that already exists */
s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
mntroot = ERR_CAST(s);
goto out_err_nosb;
}
@ -2325,8 +2356,10 @@ static int nfs_get_sb(struct file_system_type *fs_type,
server = NULL;
} else {
error = nfs_bdi_register(server);
if (error)
if (error) {
mntroot = ERR_PTR(error);
goto error_splat_bdi;
}
}
if (!s->s_root) {
@ -2336,20 +2369,15 @@ static int nfs_get_sb(struct file_system_type *fs_type,
s, data ? data->fscache_uniq : NULL, NULL);
}
mntroot = nfs_get_root(s, mntfh);
if (IS_ERR(mntroot)) {
error = PTR_ERR(mntroot);
mntroot = nfs_get_root(s, mntfh, dev_name);
if (IS_ERR(mntroot))
goto error_splat_super;
}
error = security_sb_set_mnt_opts(s, &data->lsm_opts);
if (error)
goto error_splat_root;
s->s_flags |= MS_ACTIVE;
mnt->mnt_sb = s;
mnt->mnt_root = mntroot;
error = 0;
out:
kfree(data->nfs_server.hostname);
@ -2359,7 +2387,7 @@ out:
out_free_fh:
nfs_free_fhandle(mntfh);
kfree(data);
return error;
return mntroot;
out_err_nosb:
nfs_free_server(server);
@ -2367,6 +2395,7 @@ out_err_nosb:
error_splat_root:
dput(mntroot);
mntroot = ERR_PTR(error);
error_splat_super:
if (server && !s->s_root)
bdi_unregister(&server->backing_dev_info);
@ -2450,7 +2479,7 @@ nfs_xdev_mount(struct file_system_type *fs_type, int flags,
nfs_fscache_get_super_cookie(s, NULL, data);
}
mntroot = nfs_get_root(s, data->fh);
mntroot = nfs_get_root(s, data->fh, dev_name);
if (IS_ERR(mntroot)) {
error = PTR_ERR(mntroot);
goto error_splat_super;
@ -2718,7 +2747,7 @@ nfs4_remote_mount(struct file_system_type *fs_type, int flags,
s, data ? data->fscache_uniq : NULL, NULL);
}
mntroot = nfs4_get_root(s, mntfh);
mntroot = nfs4_get_root(s, mntfh, dev_name);
if (IS_ERR(mntroot)) {
error = PTR_ERR(mntroot);
goto error_splat_super;
@ -2771,27 +2800,6 @@ static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
return root_mnt;
}
static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
{
char *page = (char *) __get_free_page(GFP_KERNEL);
char *devname, *tmp;
if (page == NULL)
return;
devname = nfs_path(path->mnt->mnt_devname,
path->mnt->mnt_root, path->dentry,
page, PAGE_SIZE);
if (IS_ERR(devname))
goto out_freepage;
tmp = kstrdup(devname, GFP_KERNEL);
if (tmp == NULL)
goto out_freepage;
kfree(mnt->mnt_devname);
mnt->mnt_devname = tmp;
out_freepage:
free_page((unsigned long)page);
}
struct nfs_referral_count {
struct list_head list;
const struct task_struct *task;
@ -2858,17 +2866,18 @@ static void nfs_referral_loop_unprotect(void)
kfree(p);
}
static int nfs_follow_remote_path(struct vfsmount *root_mnt,
const char *export_path, struct vfsmount *mnt_target)
static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
const char *export_path)
{
struct nameidata *nd = NULL;
struct mnt_namespace *ns_private;
struct super_block *s;
struct dentry *dentry;
int ret;
nd = kmalloc(sizeof(*nd), GFP_KERNEL);
if (nd == NULL)
return -ENOMEM;
return ERR_PTR(-ENOMEM);
ns_private = create_mnt_ns(root_mnt);
ret = PTR_ERR(ns_private);
@ -2890,32 +2899,27 @@ static int nfs_follow_remote_path(struct vfsmount *root_mnt,
s = nd->path.mnt->mnt_sb;
atomic_inc(&s->s_active);
mnt_target->mnt_sb = s;
mnt_target->mnt_root = dget(nd->path.dentry);
/* Correct the device pathname */
nfs_fix_devname(&nd->path, mnt_target);
dentry = dget(nd->path.dentry);
path_put(&nd->path);
kfree(nd);
down_write(&s->s_umount);
return 0;
return dentry;
out_put_mnt_ns:
put_mnt_ns(ns_private);
out_mntput:
mntput(root_mnt);
out_err:
kfree(nd);
return ret;
return ERR_PTR(ret);
}
static int nfs4_try_mount(int flags, const char *dev_name,
struct nfs_parsed_mount_data *data,
struct vfsmount *mnt)
static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
struct nfs_parsed_mount_data *data)
{
char *export_path;
struct vfsmount *root_mnt;
int error;
struct dentry *res;
dfprintk(MOUNT, "--> nfs4_try_mount()\n");
@ -2925,26 +2929,25 @@ static int nfs4_try_mount(int flags, const char *dev_name,
data->nfs_server.hostname);
data->nfs_server.export_path = export_path;
error = PTR_ERR(root_mnt);
if (IS_ERR(root_mnt))
goto out;
res = ERR_CAST(root_mnt);
if (!IS_ERR(root_mnt))
res = nfs_follow_remote_path(root_mnt, export_path);
error = nfs_follow_remote_path(root_mnt, export_path, mnt);
out:
dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
error != 0 ? " [error]" : "");
return error;
dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
IS_ERR(res) ? PTR_ERR(res) : 0,
IS_ERR(res) ? " [error]" : "");
return res;
}
/*
* Get the superblock for an NFS4 mountpoint
*/
static int nfs4_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
static struct dentry *nfs4_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data)
{
struct nfs_parsed_mount_data *data;
int error = -ENOMEM;
struct dentry *res = ERR_PTR(-ENOMEM);
data = nfs_alloc_parsed_mount_data(4);
if (data == NULL)
@ -2952,10 +2955,14 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
/* Validate the mount data */
error = nfs4_validate_mount_data(raw_data, data, dev_name);
if (error < 0)
if (error < 0) {
res = ERR_PTR(error);
goto out;
}
error = nfs4_try_mount(flags, dev_name, data, mnt);
res = nfs4_try_mount(flags, dev_name, data);
if (IS_ERR(res))
error = PTR_ERR(res);
out:
kfree(data->client_address);
@ -2964,9 +2971,9 @@ out:
kfree(data->fscache_uniq);
out_free_data:
kfree(data);
dprintk("<-- nfs4_get_sb() = %d%s\n", error,
dprintk("<-- nfs4_mount() = %d%s\n", error,
error != 0 ? " [error]" : "");
return error;
return res;
}
static void nfs4_kill_super(struct super_block *sb)
@ -3033,7 +3040,7 @@ nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
nfs_fscache_get_super_cookie(s, NULL, data);
}
mntroot = nfs4_get_root(s, data->fh);
mntroot = nfs4_get_root(s, data->fh, dev_name);
if (IS_ERR(mntroot)) {
error = PTR_ERR(mntroot);
goto error_splat_super;
@ -3120,7 +3127,7 @@ nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
nfs_fscache_get_super_cookie(s, NULL, data);
}
mntroot = nfs4_get_root(s, mntfh);
mntroot = nfs4_get_root(s, mntfh, dev_name);
if (IS_ERR(mntroot)) {
error = PTR_ERR(mntroot);
goto error_splat_super;
@ -3160,16 +3167,15 @@ error_splat_bdi:
/*
* Create an NFS4 server record on referral traversal
*/
static int nfs4_referral_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data,
struct vfsmount *mnt)
static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data)
{
struct nfs_clone_mount *data = raw_data;
char *export_path;
struct vfsmount *root_mnt;
int error;
struct dentry *res;
dprintk("--> nfs4_referral_get_sb()\n");
dprintk("--> nfs4_referral_mount()\n");
export_path = data->mnt_path;
data->mnt_path = "/";
@ -3178,15 +3184,13 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type,
flags, data, data->hostname);
data->mnt_path = export_path;
error = PTR_ERR(root_mnt);
if (IS_ERR(root_mnt))
goto out;
error = nfs_follow_remote_path(root_mnt, export_path, mnt);
out:
dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
error != 0 ? " [error]" : "");
return error;
res = ERR_CAST(root_mnt);
if (!IS_ERR(root_mnt))
res = nfs_follow_remote_path(root_mnt, export_path);
dprintk("<-- nfs4_referral_mount() = %ld%s\n",
IS_ERR(res) ? PTR_ERR(res) : 0,
IS_ERR(res) ? " [error]" : "");
return res;
}
#endif /* CONFIG_NFS_V4 */

20
fs/nfs/unlink.c
View file

@ -148,6 +148,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
alias = d_lookup(parent, &data->args.name);
if (alias != NULL) {
int ret = 0;
void *devname_garbage = NULL;
/*
* Hey, we raced with lookup... See if we need to transfer
@ -157,6 +158,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
spin_lock(&alias->d_lock);
if (alias->d_inode != NULL &&
!(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
devname_garbage = alias->d_fsdata;
alias->d_fsdata = data;
alias->d_flags |= DCACHE_NFSFS_RENAMED;
ret = 1;
@ -164,6 +166,13 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
spin_unlock(&alias->d_lock);
nfs_dec_sillycount(dir);
dput(alias);
/*
* If we'd displaced old cached devname, free it. At that
* point dentry is definitely not a root, so we won't need
* that anymore.
*/
if (devname_garbage)
kfree(devname_garbage);
return ret;
}
data->dir = igrab(dir);
@ -252,6 +261,7 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry)
{
struct nfs_unlinkdata *data;
int status = -ENOMEM;
void *devname_garbage = NULL;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL)
@ -269,8 +279,16 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry)
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
goto out_unlock;
dentry->d_flags |= DCACHE_NFSFS_RENAMED;
devname_garbage = dentry->d_fsdata;
dentry->d_fsdata = data;
spin_unlock(&dentry->d_lock);
/*
* If we'd displaced old cached devname, free it. At that
* point dentry is definitely not a root, so we won't need
* that anymore.
*/
if (devname_garbage)
kfree(devname_garbage);
return 0;
out_unlock:
spin_unlock(&dentry->d_lock);
@ -299,6 +317,7 @@ nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
data = dentry->d_fsdata;
dentry->d_fsdata = NULL;
}
spin_unlock(&dentry->d_lock);
@ -315,6 +334,7 @@ nfs_cancel_async_unlink(struct dentry *dentry)
struct nfs_unlinkdata *data = dentry->d_fsdata;
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
dentry->d_fsdata = NULL;
spin_unlock(&dentry->d_lock);
nfs_free_unlinkdata(data);
return;

67
fs/super.c
View file

@ -843,23 +843,6 @@ error:
}
EXPORT_SYMBOL(mount_bdev);
int get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt)
{
struct dentry *root;
root = mount_bdev(fs_type, flags, dev_name, data, fill_super);
if (IS_ERR(root))
return PTR_ERR(root);
mnt->mnt_root = root;
mnt->mnt_sb = root->d_sb;
return 0;
}
EXPORT_SYMBOL(get_sb_bdev);
void kill_block_super(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
@ -897,22 +880,6 @@ struct dentry *mount_nodev(struct file_system_type *fs_type,
}
EXPORT_SYMBOL(mount_nodev);
int get_sb_nodev(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt)
{
struct dentry *root;
root = mount_nodev(fs_type, flags, data, fill_super);
if (IS_ERR(root))
return PTR_ERR(root);
mnt->mnt_root = root;
mnt->mnt_sb = root->d_sb;
return 0;
}
EXPORT_SYMBOL(get_sb_nodev);
static int compare_single(struct super_block *s, void *p)
{
return 1;
@ -943,22 +910,6 @@ struct dentry *mount_single(struct file_system_type *fs_type,
}
EXPORT_SYMBOL(mount_single);
int get_sb_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt)
{
struct dentry *root;
root = mount_single(fs_type, flags, data, fill_super);
if (IS_ERR(root))
return PTR_ERR(root);
mnt->mnt_root = root;
mnt->mnt_sb = root->d_sb;
return 0;
}
EXPORT_SYMBOL(get_sb_single);
struct vfsmount *
vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
{
@ -988,19 +939,13 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
goto out_free_secdata;
}
if (type->mount) {
root = type->mount(type, flags, name, data);
if (IS_ERR(root)) {
error = PTR_ERR(root);
goto out_free_secdata;
}
mnt->mnt_root = root;
mnt->mnt_sb = root->d_sb;
} else {
error = type->get_sb(type, flags, name, data, mnt);
if (error < 0)
goto out_free_secdata;
root = type->mount(type, flags, name, data);
if (IS_ERR(root)) {
error = PTR_ERR(root);
goto out_free_secdata;
}
mnt->mnt_root = root;
mnt->mnt_sb = root->d_sb;
BUG_ON(!mnt->mnt_sb);
WARN_ON(!mnt->mnt_sb->s_bdi);
mnt->mnt_sb->s_flags |= MS_BORN;

16
include/linux/fs.h
View file

@ -1631,6 +1631,8 @@ struct super_operations {
void (*umount_begin) (struct super_block *);
int (*show_options)(struct seq_file *, struct vfsmount *);
int (*show_devname)(struct seq_file *, struct vfsmount *);
int (*show_path)(struct seq_file *, struct vfsmount *);
int (*show_stats)(struct seq_file *, struct vfsmount *);
#ifdef CONFIG_QUOTA
ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
@ -1794,8 +1796,6 @@ int sync_inode_metadata(struct inode *inode, int wait);
struct file_system_type {
const char *name;
int fs_flags;
int (*get_sb) (struct file_system_type *, int,
const char *, void *, struct vfsmount *);
struct dentry *(*mount) (struct file_system_type *, int,
const char *, void *);
void (*kill_sb) (struct super_block *);
@ -1818,24 +1818,12 @@ extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
extern struct dentry *mount_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern int get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt);
extern struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern int get_sb_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt);
extern struct dentry *mount_nodev(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern int get_sb_nodev(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt);
void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
void kill_anon_super(struct super_block *sb);