/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- rpc_purge_list
- rpc_timeout_upcall_queue
- rpc_queue_upcall
- rpc_inode_setowner
- rpc_close_pipes
- rpc_alloc_inode
- rpc_destroy_inode
- rpc_pipe_open
- rpc_pipe_release
- rpc_pipe_read
- rpc_pipe_write
- rpc_pipe_poll
- rpc_pipe_ioctl
- rpc_show_info
- rpc_info_open
- rpc_info_release
- rpc_get_mount
- rpc_put_mount
- rpc_delete_dentry
- rpc_lookup_parent
- rpc_release_path
- rpc_get_inode
- rpc_depopulate
- rpc_populate
- __rpc_mkdir
- __rpc_rmdir
- rpc_lookup_create
- rpc_lookup_negative
- rpc_mkdir
- rpc_rmdir
- rpc_mkpipe
- rpc_unlink
- rpc_fill_super
- rpc_get_sb
- init_once
- register_rpc_pipefs
- unregister_rpc_pipefs
/*
* net/sunrpc/rpc_pipe.c
*
* Userland/kernel interface for rpcauth_gss.
* Code shamelessly plagiarized from fs/nfsd/nfsctl.c
* and fs/sysfs/inode.c
*
* Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
*
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/fsnotify.h>
#include <linux/kernel.h>
#include <asm/ioctls.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <linux/seq_file.h>
#include <linux/sunrpc/clnt.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
static struct vfsmount *rpc_mount __read_mostly;
static int rpc_mount_count;
static struct file_system_type rpc_pipe_fs_type;
static struct kmem_cache *rpc_inode_cachep __read_mostly;
#define RPC_UPCALL_TIMEOUT (30*HZ)
static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
void (*destroy_msg)(struct rpc_pipe_msg *), int err)
{
struct rpc_pipe_msg *msg;
if (list_empty(head))
return;
do {
msg = list_entry(head->next, struct rpc_pipe_msg, list);
list_del(&msg->list);
msg->errno = err;
destroy_msg(msg);
} while (!list_empty(head));
wake_up(&rpci->waitq);
}
static void
rpc_timeout_upcall_queue(struct work_struct *work)
{
LIST_HEAD(free_list);
struct rpc_inode *rpci =
container_of(work, struct rpc_inode, queue_timeout.work);
struct inode *inode = &rpci->vfs_inode;
void (*destroy_msg)(struct rpc_pipe_msg *);
spin_lock(&inode->i_lock);
if (rpci->ops == NULL) {
spin_unlock(&inode->i_lock);
return;
}
destroy_msg = rpci->ops->destroy_msg;
if (rpci->nreaders == 0) {
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
}
spin_unlock(&inode->i_lock);
rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
}
/**
* rpc_queue_upcall
* @inode: inode of upcall pipe on which to queue given message
* @msg: message to queue
*
* Call with an @inode created by rpc_mkpipe() to queue an upcall.
* A userspace process may then later read the upcall by performing a
* read on an open file for this inode. It is up to the caller to
* initialize the fields of @msg (other than @msg->list) appropriately.
*/
int
rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
{
struct rpc_inode *rpci = RPC_I(inode);
int res = -EPIPE;
spin_lock(&inode->i_lock);
if (rpci->ops == NULL)
goto out;
if (rpci->nreaders) {
list_add_tail(&msg->list, &rpci->pipe);
rpci->pipelen += msg->len;
res = 0;
} else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
if (list_empty(&rpci->pipe))
queue_delayed_work(rpciod_workqueue,
&rpci->queue_timeout,
RPC_UPCALL_TIMEOUT);
list_add_tail(&msg->list, &rpci->pipe);
rpci->pipelen += msg->len;
res = 0;
}
out:
spin_unlock(&inode->i_lock);
wake_up(&rpci->waitq);
return res;
}
EXPORT_SYMBOL(rpc_queue_upcall);
static inline void
rpc_inode_setowner(struct inode *inode, void *private)
{
RPC_I(inode)->private = private;
}
static void
rpc_close_pipes(struct inode *inode)
{
struct rpc_inode *rpci = RPC_I(inode);
struct rpc_pipe_ops *ops;
mutex_lock(&inode->i_mutex);
ops = rpci->ops;
if (ops != NULL) {
LIST_HEAD(free_list);
spin_lock(&inode->i_lock);
rpci->nreaders = 0;
list_splice_init(&rpci->in_upcall, &free_list);
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
rpci->ops = NULL;
spin_unlock(&inode->i_lock);
rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
rpci->nwriters = 0;
if (ops->release_pipe)
ops->release_pipe(inode);
cancel_delayed_work_sync(&rpci->queue_timeout);
}
rpc_inode_setowner(inode, NULL);
mutex_unlock(&inode->i_mutex);
}
static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
struct rpc_inode *rpci;
rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
if (!rpci)
return NULL;
return &rpci->vfs_inode;
}
static void
rpc_destroy_inode(struct inode *inode)
{
kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
}
static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
struct rpc_inode *rpci = RPC_I(inode);
int res = -ENXIO;
mutex_lock(&inode->i_mutex);
if (rpci->ops != NULL) {
if (filp->f_mode & FMODE_READ)
rpci->nreaders ++;
if (filp->f_mode & FMODE_WRITE)
rpci->nwriters ++;
res = 0;
}
mutex_unlock(&inode->i_mutex);
return res;
}
static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
struct rpc_inode *rpci = RPC_I(inode);
struct rpc_pipe_msg *msg;
mutex_lock(&inode->i_mutex);
if (rpci->ops == NULL)
goto out;
msg = (struct rpc_pipe_msg *)filp->private_data;
if (msg != NULL) {
spin_lock(&inode->i_lock);
msg->errno = -EAGAIN;
list_del(&msg->list);
spin_unlock(&inode->i_lock);
rpci->ops->destroy_msg(msg);
}
if (filp->f_mode & FMODE_WRITE)
rpci->nwriters --;
if (filp->f_mode & FMODE_READ) {
rpci->nreaders --;
if (rpci->nreaders == 0) {
LIST_HEAD(free_list);
spin_lock(&inode->i_lock);
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
spin_unlock(&inode->i_lock);
rpc_purge_list(rpci, &free_list,
rpci->ops->destroy_msg, -EAGAIN);
}
}
if (rpci->ops->release_pipe)
rpci->ops->release_pipe(inode);
out:
mutex_unlock(&inode->i_mutex);
return 0;
}
static ssize_t
rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct rpc_inode *rpci = RPC_I(inode);
struct rpc_pipe_msg *msg;
int res = 0;
mutex_lock(&inode->i_mutex);
if (rpci->ops == NULL) {
res = -EPIPE;
goto out_unlock;
}
msg = filp->private_data;
if (msg == NULL) {
spin_lock(&inode->i_lock);
if (!list_empty(&rpci->pipe)) {
msg = list_entry(rpci->pipe.next,
struct rpc_pipe_msg,
list);
list_move(&msg->list, &rpci->in_upcall);
rpci->pipelen -= msg->len;
filp->private_data = msg;
msg->copied = 0;
}
spin_unlock(&inode->i_lock);
if (msg == NULL)
goto out_unlock;
}
/* NOTE: it is up to the callback to update msg->copied */
res = rpci->ops->upcall(filp, msg, buf, len);
if (res < 0 || msg->len == msg->copied) {
filp->private_data = NULL;
spin_lock(&inode->i_lock);
list_del(&msg->list);
spin_unlock(&inode->i_lock);
rpci->ops->destroy_msg(msg);
}
out_unlock:
mutex_unlock(&inode->i_mutex);
return res;
}
static ssize_t
rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct rpc_inode *rpci = RPC_I(inode);
int res;
mutex_lock(&inode->i_mutex);
res = -EPIPE;
if (rpci->ops != NULL)
res = rpci->ops->downcall(filp, buf, len);
mutex_unlock(&inode->i_mutex);
return res;
}
static unsigned int
rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
{
struct rpc_inode *rpci;
unsigned int mask = 0;
rpci = RPC_I(filp->f_path.dentry->d_inode);
poll_wait(filp, &rpci->waitq, wait);
mask = POLLOUT | POLLWRNORM;
if (rpci->ops == NULL)
mask |= POLLERR | POLLHUP;
if (filp->private_data || !list_empty(&rpci->pipe))
mask |= POLLIN | POLLRDNORM;
return mask;
}
static int
rpc_pipe_ioctl(struct inode *ino, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
int len;
switch (cmd) {
case FIONREAD:
if (rpci->ops == NULL)
return -EPIPE;
len = rpci->pipelen;
if (filp->private_data) {
struct rpc_pipe_msg *msg;
msg = (struct rpc_pipe_msg *)filp->private_data;
len += msg->len - msg->copied;
}
return put_user(len, (int __user *)arg);
default:
return -EINVAL;
}
}
static const struct file_operations rpc_pipe_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = rpc_pipe_read,
.write = rpc_pipe_write,
.poll = rpc_pipe_poll,
.ioctl = rpc_pipe_ioctl,
.open = rpc_pipe_open,
.release = rpc_pipe_release,
};
static int
rpc_show_info(struct seq_file *m, void *v)
{
struct rpc_clnt *clnt = m->private;
seq_printf(m, "RPC server: %s\n", clnt->cl_server);
seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
clnt->cl_prog, clnt->cl_vers);
seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
return 0;
}
static int
rpc_info_open(struct inode *inode, struct file *file)
{
struct rpc_clnt *clnt;
int ret = single_open(file, rpc_show_info, NULL);
if (!ret) {
struct seq_file *m = file->private_data;
mutex_lock(&inode->i_mutex);
clnt = RPC_I(inode)->private;
if (clnt) {
kref_get(&clnt->cl_kref);
m->private = clnt;
} else {
single_release(inode, file);
ret = -EINVAL;
}
mutex_unlock(&inode->i_mutex);
}
return ret;
}
static int
rpc_info_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
if (clnt)
rpc_release_client(clnt);
return single_release(inode, file);
}
static const struct file_operations rpc_info_operations = {
.owner = THIS_MODULE,
.open = rpc_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = rpc_info_release,
};
/*
* We have a single directory with 1 node in it.
*/
enum {
RPCAUTH_Root = 1,
RPCAUTH_lockd,
RPCAUTH_mount,
RPCAUTH_nfs,
RPCAUTH_portmap,
RPCAUTH_statd,
RPCAUTH_RootEOF
};
/*
* Description of fs contents.
*/
struct rpc_filelist {
char *name;
const struct file_operations *i_fop;
int mode;
};
static struct rpc_filelist files[] = {
[RPCAUTH_lockd] = {
.name = "lockd",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_mount] = {
.name = "mount",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_nfs] = {
.name = "nfs",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_portmap] = {
.name = "portmap",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_statd] = {
.name = "statd",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
};
enum {
RPCAUTH_info = 2,
RPCAUTH_EOF
};
static struct rpc_filelist authfiles[] = {
[RPCAUTH_info] = {
.name = "info",
.i_fop = &rpc_info_operations,
.mode = S_IFREG | S_IRUSR,
},
};
struct vfsmount *rpc_get_mount(void)
{
int err;
err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
if (err != 0)
return ERR_PTR(err);
return rpc_mount;
}
void rpc_put_mount(void)
{
simple_release_fs(&rpc_mount, &rpc_mount_count);
}
static int rpc_delete_dentry(struct dentry *dentry)
{
return 1;
}
static struct dentry_operations rpc_dentry_operations = {
.d_delete = rpc_delete_dentry,
};
static int
rpc_lookup_parent(char *path, struct nameidata *nd)
{
struct vfsmount *mnt;
if (path[0] == '\0')
return -ENOENT;
mnt = rpc_get_mount();
if (IS_ERR(mnt)) {
printk(KERN_WARNING "%s: %s failed to mount "
"pseudofilesystem \n", __FILE__, __func__);
return PTR_ERR(mnt);
}
if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
printk(KERN_WARNING "%s: %s failed to find path %s\n",
__FILE__, __func__, path);
rpc_put_mount();
return -ENOENT;
}
return 0;
}
static void
rpc_release_path(struct nameidata *nd)
{
path_put(&nd->path);
rpc_put_mount();
}
static struct inode *
rpc_get_inode(struct super_block *sb, int mode)
{
struct inode *inode = new_inode(sb);
if (!inode)
return NULL;
inode->i_mode = mode;
inode->i_uid = inode->i_gid = 0;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
switch(mode & S_IFMT) {
case S_IFDIR:
inode->i_fop = &simple_dir_operations;
inode->i_op = &simple_dir_inode_operations;
inc_nlink(inode);
default:
break;
}
return inode;
}
/*
* FIXME: This probably has races.
*/
static void rpc_depopulate(struct dentry *parent,
unsigned long start, unsigned long eof)
{
struct inode *dir = parent->d_inode;
struct list_head *pos, *next;
struct dentry *dentry, *dvec[10];
int n = 0;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
repeat:
spin_lock(&dcache_lock);
list_for_each_safe(pos, next, &parent->d_subdirs) {
dentry = list_entry(pos, struct dentry, d_u.d_child);
if (!dentry->d_inode ||
dentry->d_inode->i_ino < start ||
dentry->d_inode->i_ino >= eof)
continue;
spin_lock(&dentry->d_lock);
if (!d_unhashed(dentry)) {
dget_locked(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
dvec[n++] = dentry;
if (n == ARRAY_SIZE(dvec))
break;
} else
spin_unlock(&dentry->d_lock);
}
spin_unlock(&dcache_lock);
if (n) {
do {
dentry = dvec[--n];
if (S_ISREG(dentry->d_inode->i_mode))
simple_unlink(dir, dentry);
else if (S_ISDIR(dentry->d_inode->i_mode))
simple_rmdir(dir, dentry);
d_delete(dentry);
dput(dentry);
} while (n);
goto repeat;
}
mutex_unlock(&dir->i_mutex);
}
static int
rpc_populate(struct dentry *parent,
struct rpc_filelist *files,
int start, int eof)
{
struct inode *inode, *dir = parent->d_inode;
void *private = RPC_I(dir)->private;
struct dentry *dentry;
int mode, i;
mutex_lock(&dir->i_mutex);
for (i = start; i < eof; i++) {
dentry = d_alloc_name(parent, files[i].name);
if (!dentry)
goto out_bad;
dentry->d_op = &rpc_dentry_operations;
mode = files[i].mode;
inode = rpc_get_inode(dir->i_sb, mode);
if (!inode) {
dput(dentry);
goto out_bad;
}
inode->i_ino = i;
if (files[i].i_fop)
inode->i_fop = files[i].i_fop;
if (private)
rpc_inode_setowner(inode, private);
if (S_ISDIR(mode))
inc_nlink(dir);
d_add(dentry, inode);
fsnotify_create(dir, dentry);
}
mutex_unlock(&dir->i_mutex);
return 0;
out_bad:
mutex_unlock(&dir->i_mutex);
printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
__FILE__, __func__, parent->d_name.name);
return -ENOMEM;
}
static int
__rpc_mkdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode;
inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
goto out_err;
inode->i_ino = iunique(dir->i_sb, 100);
d_instantiate(dentry, inode);
inc_nlink(dir);
fsnotify_mkdir(dir, dentry);
return 0;
out_err:
printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
__FILE__, __func__, dentry->d_name.name);
return -ENOMEM;
}
static int
__rpc_rmdir(struct inode *dir, struct dentry *dentry)
{
int error;
error = simple_rmdir(dir, dentry);
if (!error)
d_delete(dentry);
return error;
}
static struct dentry *
rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
{
struct inode *dir = parent->d_inode;
struct dentry *dentry;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent, len);
if (IS_ERR(dentry))
goto out_err;
if (!dentry->d_inode)
dentry->d_op = &rpc_dentry_operations;
else if (exclusive) {
dput(dentry);
dentry = ERR_PTR(-EEXIST);
goto out_err;
}
return dentry;
out_err:
mutex_unlock(&dir->i_mutex);
return dentry;
}
static struct dentry *
rpc_lookup_negative(char *path, struct nameidata *nd)
{
struct dentry *dentry;
int error;
if ((error = rpc_lookup_parent(path, nd)) != 0)
return ERR_PTR(error);
dentry = rpc_lookup_create(nd->path.dentry, nd->last.name, nd->last.len,
1);
if (IS_ERR(dentry))
rpc_release_path(nd);
return dentry;
}
/**
* rpc_mkdir - Create a new directory in rpc_pipefs
* @path: path from the rpc_pipefs root to the new directory
* @rpc_client: rpc client to associate with this directory
*
* This creates a directory at the given @path associated with
* @rpc_clnt, which will contain a file named "info" with some basic
* information about the client, together with any "pipes" that may
* later be created using rpc_mkpipe().
*/
struct dentry *
rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
{
struct nameidata nd;
struct dentry *dentry;
struct inode *dir;
int error;
dentry = rpc_lookup_negative(path, &nd);
if (IS_ERR(dentry))
return dentry;
dir = nd.path.dentry->d_inode;
if ((error = __rpc_mkdir(dir, dentry)) != 0)
goto err_dput;
RPC_I(dentry->d_inode)->private = rpc_client;
error = rpc_populate(dentry, authfiles,
RPCAUTH_info, RPCAUTH_EOF);
if (error)
goto err_depopulate;
dget(dentry);
out:
mutex_unlock(&dir->i_mutex);
rpc_release_path(&nd);
return dentry;
err_depopulate:
rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
__rpc_rmdir(dir, dentry);
err_dput:
dput(dentry);
printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
__FILE__, __func__, path, error);
dentry = ERR_PTR(error);
goto out;
}
/**
* rpc_rmdir - Remove a directory created with rpc_mkdir()
* @dentry: directory to remove
*/
int
rpc_rmdir(struct dentry *dentry)
{
struct dentry *parent;
struct inode *dir;
int error;
parent = dget_parent(dentry);
dir = parent->d_inode;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
error = __rpc_rmdir(dir, dentry);
dput(dentry);
mutex_unlock(&dir->i_mutex);
dput(parent);
return error;
}
/**
* rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
* @parent: dentry of directory to create new "pipe" in
* @name: name of pipe
* @private: private data to associate with the pipe, for the caller's use
* @ops: operations defining the behavior of the pipe: upcall, downcall,
* release_pipe, and destroy_msg.
* @flags: rpc_inode flags
*
* Data is made available for userspace to read by calls to
* rpc_queue_upcall(). The actual reads will result in calls to
* @ops->upcall, which will be called with the file pointer,
* message, and userspace buffer to copy to.
*
* Writes can come at any time, and do not necessarily have to be
* responses to upcalls. They will result in calls to @msg->downcall.
*
* The @private argument passed here will be available to all these methods
* from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
*/
struct dentry *
rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
{
struct dentry *dentry;
struct inode *dir, *inode;
struct rpc_inode *rpci;
dentry = rpc_lookup_create(parent, name, strlen(name), 0);
if (IS_ERR(dentry))
return dentry;
dir = parent->d_inode;
if (dentry->d_inode) {
rpci = RPC_I(dentry->d_inode);
if (rpci->private != private ||
rpci->ops != ops ||
rpci->flags != flags) {
dput (dentry);
dentry = ERR_PTR(-EBUSY);
}
rpci->nkern_readwriters++;
goto out;
}
inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
if (!inode)
goto err_dput;
inode->i_ino = iunique(dir->i_sb, 100);
inode->i_fop = &rpc_pipe_fops;
d_instantiate(dentry, inode);
rpci = RPC_I(inode);
rpci->private = private;
rpci->flags = flags;
rpci->ops = ops;
rpci->nkern_readwriters = 1;
fsnotify_create(dir, dentry);
dget(dentry);
out:
mutex_unlock(&dir->i_mutex);
return dentry;
err_dput:
dput(dentry);
dentry = ERR_PTR(-ENOMEM);
printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
__FILE__, __func__, parent->d_name.name, name,
-ENOMEM);
goto out;
}
EXPORT_SYMBOL(rpc_mkpipe);
/**
* rpc_unlink - remove a pipe
* @dentry: dentry for the pipe, as returned from rpc_mkpipe
*
* After this call, lookups will no longer find the pipe, and any
* attempts to read or write using preexisting opens of the pipe will
* return -EPIPE.
*/
int
rpc_unlink(struct dentry *dentry)
{
struct dentry *parent;
struct inode *dir;
int error = 0;
parent = dget_parent(dentry);
dir = parent->d_inode;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
rpc_close_pipes(dentry->d_inode);
error = simple_unlink(dir, dentry);
if (!error)
d_delete(dentry);
}
dput(dentry);
mutex_unlock(&dir->i_mutex);
dput(parent);
return error;
}
EXPORT_SYMBOL(rpc_unlink);
/*
* populate the filesystem
*/
static struct super_operations s_ops = {
.alloc_inode = rpc_alloc_inode,
.destroy_inode = rpc_destroy_inode,
.statfs = simple_statfs,
};
#define RPCAUTH_GSSMAGIC 0x67596969
static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
struct dentry *root;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = RPCAUTH_GSSMAGIC;
sb->s_op = &s_ops;
sb->s_time_gran = 1;
inode = rpc_get_inode(sb, S_IFDIR | 0755);
if (!inode)
return -ENOMEM;
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
goto out;
sb->s_root = root;
return 0;
out:
d_genocide(root);
dput(root);
return -ENOMEM;
}
static int
rpc_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
}
static struct file_system_type rpc_pipe_fs_type = {
.owner = THIS_MODULE,
.name = "rpc_pipefs",
.get_sb = rpc_get_sb,
.kill_sb = kill_litter_super,
};
static void
init_once(void *foo)
{
struct rpc_inode *rpci = (struct rpc_inode *) foo;
inode_init_once(&rpci->vfs_inode);
rpci->private = NULL;
rpci->nreaders = 0;
rpci->nwriters = 0;
INIT_LIST_HEAD(&rpci->in_upcall);
INIT_LIST_HEAD(&rpci->in_downcall);
INIT_LIST_HEAD(&rpci->pipe);
rpci->pipelen = 0;
init_waitqueue_head(&rpci->waitq);
INIT_DELAYED_WORK(&rpci->queue_timeout,
rpc_timeout_upcall_queue);
rpci->ops = NULL;
}
int register_rpc_pipefs(void)
{
int err;
rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
sizeof(struct rpc_inode),
0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (!rpc_inode_cachep)
return -ENOMEM;
err = register_filesystem(&rpc_pipe_fs_type);
if (err) {
kmem_cache_destroy(rpc_inode_cachep);
return err;
}
return 0;
}
void unregister_rpc_pipefs(void)
{
kmem_cache_destroy(rpc_inode_cachep);
unregister_filesystem(&rpc_pipe_fs_type);
}