1
linux/net/sunrpc/rpc_pipe.c
Stanislav Kinsbursky 766347bec3 SUNRPC: replace inode lock with pipe lock for RPC PipeFS operations
Currenly, inode i_lock is used to provide concurrent access to SUNPRC PipeFS
pipes. It looks redundant, since now other use of inode is present in most of
these places and thus can be easely replaced, which will allow to remove most
of inode references from PipeFS code. This is a first step towards to removing
PipeFS inode references from kernel code other than PipeFS itself.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 18:20:24 -05:00

1186 lines
28 KiB
C

/*
* 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>
#include <linux/sunrpc/cache.h>
#include <linux/nsproxy.h>
#include <linux/notifier.h>
#include "netns.h"
#include "sunrpc.h"
#define RPCDBG_FACILITY RPCDBG_DEBUG
#define NET_NAME(net) ((net == &init_net) ? " (init_net)" : "")
static struct vfsmount *rpc_mnt __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 BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
int rpc_pipefs_notifier_register(struct notifier_block *nb)
{
return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
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_init(&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);
void (*destroy_msg)(struct rpc_pipe_msg *);
spin_lock(&rpci->lock);
if (rpci->ops == NULL) {
spin_unlock(&rpci->lock);
return;
}
destroy_msg = rpci->ops->destroy_msg;
if (rpci->nreaders == 0) {
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
}
spin_unlock(&rpci->lock);
rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
}
ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
char __user *dst, size_t buflen)
{
char *data = (char *)msg->data + msg->copied;
size_t mlen = min(msg->len - msg->copied, buflen);
unsigned long left;
left = copy_to_user(dst, data, mlen);
if (left == mlen) {
msg->errno = -EFAULT;
return -EFAULT;
}
mlen -= left;
msg->copied += mlen;
msg->errno = 0;
return mlen;
}
EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
/**
* rpc_queue_upcall - queue an upcall message to userspace
* @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(&rpci->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(&rpci->lock);
wake_up(&rpci->waitq);
return res;
}
EXPORT_SYMBOL_GPL(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);
const struct rpc_pipe_ops *ops;
int need_release;
mutex_lock(&inode->i_mutex);
ops = rpci->ops;
if (ops != NULL) {
LIST_HEAD(free_list);
spin_lock(&rpci->lock);
need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
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(&rpci->lock);
rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
rpci->nwriters = 0;
if (need_release && 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_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
}
static void
rpc_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, rpc_i_callback);
}
static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
struct rpc_inode *rpci = RPC_I(inode);
int first_open;
int res = -ENXIO;
mutex_lock(&inode->i_mutex);
if (rpci->ops == NULL)
goto out;
first_open = rpci->nreaders == 0 && rpci->nwriters == 0;
if (first_open && rpci->ops->open_pipe) {
res = rpci->ops->open_pipe(inode);
if (res)
goto out;
}
if (filp->f_mode & FMODE_READ)
rpci->nreaders++;
if (filp->f_mode & FMODE_WRITE)
rpci->nwriters++;
res = 0;
out:
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;
int last_close;
mutex_lock(&inode->i_mutex);
if (rpci->ops == NULL)
goto out;
msg = filp->private_data;
if (msg != NULL) {
spin_lock(&rpci->lock);
msg->errno = -EAGAIN;
list_del_init(&msg->list);
spin_unlock(&rpci->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(&rpci->lock);
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
spin_unlock(&rpci->lock);
rpc_purge_list(rpci, &free_list,
rpci->ops->destroy_msg, -EAGAIN);
}
}
last_close = rpci->nwriters == 0 && rpci->nreaders == 0;
if (last_close && 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(&rpci->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(&rpci->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(&rpci->lock);
list_del_init(&msg->list);
spin_unlock(&rpci->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 long
rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct rpc_inode *rpci = RPC_I(inode);
int len;
switch (cmd) {
case FIONREAD:
spin_lock(&rpci->lock);
if (rpci->ops == NULL) {
spin_unlock(&rpci->lock);
return -EPIPE;
}
len = rpci->pipelen;
if (filp->private_data) {
struct rpc_pipe_msg *msg;
msg = filp->private_data;
len += msg->len - msg->copied;
}
spin_unlock(&rpci->lock);
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,
.unlocked_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 = NULL;
int ret = single_open(file, rpc_show_info, NULL);
if (!ret) {
struct seq_file *m = file->private_data;
spin_lock(&file->f_path.dentry->d_lock);
if (!d_unhashed(file->f_path.dentry))
clnt = RPC_I(inode)->private;
if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
spin_unlock(&file->f_path.dentry->d_lock);
m->private = clnt;
} else {
spin_unlock(&file->f_path.dentry->d_lock);
single_release(inode, file);
ret = -EINVAL;
}
}
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,
};
/*
* Description of fs contents.
*/
struct rpc_filelist {
const char *name;
const struct file_operations *i_fop;
umode_t mode;
};
struct vfsmount *rpc_get_mount(void)
{
int err;
err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mnt, &rpc_mount_count);
if (err != 0)
return ERR_PTR(err);
return rpc_mnt;
}
EXPORT_SYMBOL_GPL(rpc_get_mount);
void rpc_put_mount(void)
{
simple_release_fs(&rpc_mnt, &rpc_mount_count);
}
EXPORT_SYMBOL_GPL(rpc_put_mount);
static int rpc_delete_dentry(const struct dentry *dentry)
{
return 1;
}
static const struct dentry_operations rpc_dentry_operations = {
.d_delete = rpc_delete_dentry,
};
static struct inode *
rpc_get_inode(struct super_block *sb, umode_t mode)
{
struct inode *inode = new_inode(sb);
if (!inode)
return NULL;
inode->i_ino = get_next_ino();
inode->i_mode = mode;
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;
}
static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
struct inode *inode;
d_drop(dentry);
inode = rpc_get_inode(dir->i_sb, mode);
if (!inode)
goto out_err;
inode->i_ino = iunique(dir->i_sb, 100);
if (i_fop)
inode->i_fop = i_fop;
if (private)
rpc_inode_setowner(inode, private);
d_add(dentry, inode);
return 0;
out_err:
printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
__FILE__, __func__, dentry->d_name.name);
dput(dentry);
return -ENOMEM;
}
static int __rpc_create(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
int err;
err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
if (err)
return err;
fsnotify_create(dir, dentry);
return 0;
}
static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
int err;
err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
if (err)
return err;
inc_nlink(dir);
fsnotify_mkdir(dir, dentry);
return 0;
}
static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private,
const struct rpc_pipe_ops *ops,
int flags)
{
struct rpc_inode *rpci;
int err;
err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
if (err)
return err;
rpci = RPC_I(dentry->d_inode);
rpci->private = private;
rpci->flags = flags;
rpci->ops = ops;
fsnotify_create(dir, dentry);
return 0;
}
static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
{
int ret;
dget(dentry);
ret = simple_rmdir(dir, dentry);
d_delete(dentry);
dput(dentry);
return ret;
}
static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
{
int ret;
dget(dentry);
ret = simple_unlink(dir, dentry);
d_delete(dentry);
dput(dentry);
return ret;
}
static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
rpc_close_pipes(inode);
return __rpc_unlink(dir, dentry);
}
static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
struct qstr *name)
{
struct dentry *dentry;
dentry = d_lookup(parent, name);
if (!dentry) {
dentry = d_alloc(parent, name);
if (!dentry)
return ERR_PTR(-ENOMEM);
}
if (dentry->d_inode == NULL) {
d_set_d_op(dentry, &rpc_dentry_operations);
return dentry;
}
dput(dentry);
return ERR_PTR(-EEXIST);
}
/*
* FIXME: This probably has races.
*/
static void __rpc_depopulate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof)
{
struct inode *dir = parent->d_inode;
struct dentry *dentry;
struct qstr name;
int i;
for (i = start; i < eof; i++) {
name.name = files[i].name;
name.len = strlen(files[i].name);
name.hash = full_name_hash(name.name, name.len);
dentry = d_lookup(parent, &name);
if (dentry == NULL)
continue;
if (dentry->d_inode == NULL)
goto next;
switch (dentry->d_inode->i_mode & S_IFMT) {
default:
BUG();
case S_IFREG:
__rpc_unlink(dir, dentry);
break;
case S_IFDIR:
__rpc_rmdir(dir, dentry);
}
next:
dput(dentry);
}
}
static void rpc_depopulate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof)
{
struct inode *dir = parent->d_inode;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
__rpc_depopulate(parent, files, start, eof);
mutex_unlock(&dir->i_mutex);
}
static int rpc_populate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof,
void *private)
{
struct inode *dir = parent->d_inode;
struct dentry *dentry;
int i, err;
mutex_lock(&dir->i_mutex);
for (i = start; i < eof; i++) {
struct qstr q;
q.name = files[i].name;
q.len = strlen(files[i].name);
q.hash = full_name_hash(q.name, q.len);
dentry = __rpc_lookup_create_exclusive(parent, &q);
err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_bad;
switch (files[i].mode & S_IFMT) {
default:
BUG();
case S_IFREG:
err = __rpc_create(dir, dentry,
files[i].mode,
files[i].i_fop,
private);
break;
case S_IFDIR:
err = __rpc_mkdir(dir, dentry,
files[i].mode,
NULL,
private);
}
if (err != 0)
goto out_bad;
}
mutex_unlock(&dir->i_mutex);
return 0;
out_bad:
__rpc_depopulate(parent, files, start, eof);
mutex_unlock(&dir->i_mutex);
printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
__FILE__, __func__, parent->d_name.name);
return err;
}
static struct dentry *rpc_mkdir_populate(struct dentry *parent,
struct qstr *name, umode_t mode, void *private,
int (*populate)(struct dentry *, void *), void *args_populate)
{
struct dentry *dentry;
struct inode *dir = parent->d_inode;
int error;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = __rpc_lookup_create_exclusive(parent, name);
if (IS_ERR(dentry))
goto out;
error = __rpc_mkdir(dir, dentry, mode, NULL, private);
if (error != 0)
goto out_err;
if (populate != NULL) {
error = populate(dentry, args_populate);
if (error)
goto err_rmdir;
}
out:
mutex_unlock(&dir->i_mutex);
return dentry;
err_rmdir:
__rpc_rmdir(dir, dentry);
out_err:
dentry = ERR_PTR(error);
goto out;
}
static int rpc_rmdir_depopulate(struct dentry *dentry,
void (*depopulate)(struct 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);
if (depopulate != NULL)
depopulate(dentry);
error = __rpc_rmdir(dir, 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, open_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, const struct rpc_pipe_ops *ops,
int flags)
{
struct dentry *dentry;
struct inode *dir = parent->d_inode;
umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
struct qstr q;
int err;
if (ops->upcall == NULL)
umode &= ~S_IRUGO;
if (ops->downcall == NULL)
umode &= ~S_IWUGO;
q.name = name;
q.len = strlen(name);
q.hash = full_name_hash(q.name, q.len),
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = __rpc_lookup_create_exclusive(parent, &q);
if (IS_ERR(dentry))
goto out;
err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops,
private, ops, flags);
if (err)
goto out_err;
out:
mutex_unlock(&dir->i_mutex);
return dentry;
out_err:
dentry = ERR_PTR(err);
printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
__FILE__, __func__, parent->d_name.name, name,
err);
goto out;
}
EXPORT_SYMBOL_GPL(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);
error = __rpc_rmpipe(dir, dentry);
mutex_unlock(&dir->i_mutex);
dput(parent);
return error;
}
EXPORT_SYMBOL_GPL(rpc_unlink);
enum {
RPCAUTH_info,
RPCAUTH_EOF
};
static const struct rpc_filelist authfiles[] = {
[RPCAUTH_info] = {
.name = "info",
.i_fop = &rpc_info_operations,
.mode = S_IFREG | S_IRUSR,
},
};
static int rpc_clntdir_populate(struct dentry *dentry, void *private)
{
return rpc_populate(dentry,
authfiles, RPCAUTH_info, RPCAUTH_EOF,
private);
}
static void rpc_clntdir_depopulate(struct dentry *dentry)
{
rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
}
/**
* rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
* @dentry: dentry from the rpc_pipefs root to the new directory
* @name: &struct qstr for the name
* @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_create_client_dir(struct dentry *dentry,
struct qstr *name,
struct rpc_clnt *rpc_client)
{
return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
rpc_clntdir_populate, rpc_client);
}
/**
* rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
* @dentry: directory to remove
*/
int rpc_remove_client_dir(struct dentry *dentry)
{
return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
}
static const struct rpc_filelist cache_pipefs_files[3] = {
[0] = {
.name = "channel",
.i_fop = &cache_file_operations_pipefs,
.mode = S_IFREG|S_IRUSR|S_IWUSR,
},
[1] = {
.name = "content",
.i_fop = &content_file_operations_pipefs,
.mode = S_IFREG|S_IRUSR,
},
[2] = {
.name = "flush",
.i_fop = &cache_flush_operations_pipefs,
.mode = S_IFREG|S_IRUSR|S_IWUSR,
},
};
static int rpc_cachedir_populate(struct dentry *dentry, void *private)
{
return rpc_populate(dentry,
cache_pipefs_files, 0, 3,
private);
}
static void rpc_cachedir_depopulate(struct dentry *dentry)
{
rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
}
struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
umode_t umode, struct cache_detail *cd)
{
return rpc_mkdir_populate(parent, name, umode, NULL,
rpc_cachedir_populate, cd);
}
void rpc_remove_cache_dir(struct dentry *dentry)
{
rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
}
/*
* populate the filesystem
*/
static const struct super_operations s_ops = {
.alloc_inode = rpc_alloc_inode,
.destroy_inode = rpc_destroy_inode,
.statfs = simple_statfs,
};
#define RPCAUTH_GSSMAGIC 0x67596969
/*
* We have a single directory with 1 node in it.
*/
enum {
RPCAUTH_lockd,
RPCAUTH_mount,
RPCAUTH_nfs,
RPCAUTH_portmap,
RPCAUTH_statd,
RPCAUTH_nfsd4_cb,
RPCAUTH_cache,
RPCAUTH_RootEOF
};
static const 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,
},
[RPCAUTH_nfsd4_cb] = {
.name = "nfsd4_cb",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_cache] = {
.name = "cache",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
};
/*
* This call can be used only in RPC pipefs mount notification hooks.
*/
struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
const unsigned char *dir_name)
{
struct qstr dir = {
.name = dir_name,
.len = strlen(dir_name),
.hash = full_name_hash(dir_name, strlen(dir_name)),
};
return d_lookup(sb->s_root, &dir);
}
EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
void rpc_pipefs_init_net(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_init(&sn->pipefs_sb_lock);
}
/*
* This call will be used for per network namespace operations calls.
* Note: Function will be returned with pipefs_sb_lock taken if superblock was
* found. This lock have to be released by rpc_put_sb_net() when all operations
* will be completed.
*/
struct super_block *rpc_get_sb_net(const struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
if (sn->pipefs_sb)
return sn->pipefs_sb;
mutex_unlock(&sn->pipefs_sb_lock);
return NULL;
}
EXPORT_SYMBOL_GPL(rpc_get_sb_net);
void rpc_put_sb_net(const struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
BUG_ON(sn->pipefs_sb == NULL);
mutex_unlock(&sn->pipefs_sb_lock);
}
EXPORT_SYMBOL_GPL(rpc_put_sb_net);
static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
struct dentry *root;
struct net *net = data;
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
int err;
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;
sb->s_root = root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
return -ENOMEM;
dprintk("RPC: sending pipefs MOUNT notification for net %p%s\n", net,
NET_NAME(net));
err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_MOUNT,
sb);
if (err)
goto err_depopulate;
sb->s_fs_info = get_net(net);
sn->pipefs_sb = sb;
return 0;
err_depopulate:
blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
return err;
}
static struct dentry *
rpc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
}
void rpc_kill_sb(struct super_block *sb)
{
struct net *net = sb->s_fs_info;
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
sn->pipefs_sb = NULL;
mutex_unlock(&sn->pipefs_sb_lock);
put_net(net);
dprintk("RPC: sending pipefs UMOUNT notification for net %p%s\n", net,
NET_NAME(net));
blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
kill_litter_super(sb);
}
static struct file_system_type rpc_pipe_fs_type = {
.owner = THIS_MODULE,
.name = "rpc_pipefs",
.mount = rpc_mount,
.kill_sb = rpc_kill_sb,
};
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;
spin_lock_init(&rpci->lock);
}
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);
}
/* Make 'mount -t rpc_pipefs ...' autoload this module. */
MODULE_ALIAS("rpc_pipefs");