linux/net/sunrpc/rpc_pipe.c
Deepa Dinamani 078cd8279e fs: Replace CURRENT_TIME with current_time() for inode timestamps
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:21 -04:00

1528 lines
36 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 <linux/rcupdate.h>
#include <linux/utsname.h>
#include <asm/ioctls.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 file_system_type rpc_pipe_fs_type;
static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
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(wait_queue_head_t *waitq, 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));
if (waitq)
wake_up(waitq);
}
static void
rpc_timeout_upcall_queue(struct work_struct *work)
{
LIST_HEAD(free_list);
struct rpc_pipe *pipe =
container_of(work, struct rpc_pipe, queue_timeout.work);
void (*destroy_msg)(struct rpc_pipe_msg *);
struct dentry *dentry;
spin_lock(&pipe->lock);
destroy_msg = pipe->ops->destroy_msg;
if (pipe->nreaders == 0) {
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
}
dentry = dget(pipe->dentry);
spin_unlock(&pipe->lock);
rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
&free_list, destroy_msg, -ETIMEDOUT);
dput(dentry);
}
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
* @pipe: 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 rpc_pipe *pipe, struct rpc_pipe_msg *msg)
{
int res = -EPIPE;
struct dentry *dentry;
spin_lock(&pipe->lock);
if (pipe->nreaders) {
list_add_tail(&msg->list, &pipe->pipe);
pipe->pipelen += msg->len;
res = 0;
} else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
if (list_empty(&pipe->pipe))
queue_delayed_work(rpciod_workqueue,
&pipe->queue_timeout,
RPC_UPCALL_TIMEOUT);
list_add_tail(&msg->list, &pipe->pipe);
pipe->pipelen += msg->len;
res = 0;
}
dentry = dget(pipe->dentry);
spin_unlock(&pipe->lock);
if (dentry) {
wake_up(&RPC_I(d_inode(dentry))->waitq);
dput(dentry);
}
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_pipe *pipe = RPC_I(inode)->pipe;
int need_release;
LIST_HEAD(free_list);
inode_lock(inode);
spin_lock(&pipe->lock);
need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
pipe->nreaders = 0;
list_splice_init(&pipe->in_upcall, &free_list);
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
pipe->dentry = NULL;
spin_unlock(&pipe->lock);
rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
pipe->nwriters = 0;
if (need_release && pipe->ops->release_pipe)
pipe->ops->release_pipe(inode);
cancel_delayed_work_sync(&pipe->queue_timeout);
rpc_inode_setowner(inode, NULL);
RPC_I(inode)->pipe = NULL;
inode_unlock(inode);
}
static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
struct rpc_inode *rpci;
rpci = 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_pipe *pipe;
int first_open;
int res = -ENXIO;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL)
goto out;
first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
if (first_open && pipe->ops->open_pipe) {
res = pipe->ops->open_pipe(inode);
if (res)
goto out;
}
if (filp->f_mode & FMODE_READ)
pipe->nreaders++;
if (filp->f_mode & FMODE_WRITE)
pipe->nwriters++;
res = 0;
out:
inode_unlock(inode);
return res;
}
static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
struct rpc_pipe *pipe;
struct rpc_pipe_msg *msg;
int last_close;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL)
goto out;
msg = filp->private_data;
if (msg != NULL) {
spin_lock(&pipe->lock);
msg->errno = -EAGAIN;
list_del_init(&msg->list);
spin_unlock(&pipe->lock);
pipe->ops->destroy_msg(msg);
}
if (filp->f_mode & FMODE_WRITE)
pipe->nwriters --;
if (filp->f_mode & FMODE_READ) {
pipe->nreaders --;
if (pipe->nreaders == 0) {
LIST_HEAD(free_list);
spin_lock(&pipe->lock);
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
spin_unlock(&pipe->lock);
rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
pipe->ops->destroy_msg, -EAGAIN);
}
}
last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
if (last_close && pipe->ops->release_pipe)
pipe->ops->release_pipe(inode);
out:
inode_unlock(inode);
return 0;
}
static ssize_t
rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = file_inode(filp);
struct rpc_pipe *pipe;
struct rpc_pipe_msg *msg;
int res = 0;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL) {
res = -EPIPE;
goto out_unlock;
}
msg = filp->private_data;
if (msg == NULL) {
spin_lock(&pipe->lock);
if (!list_empty(&pipe->pipe)) {
msg = list_entry(pipe->pipe.next,
struct rpc_pipe_msg,
list);
list_move(&msg->list, &pipe->in_upcall);
pipe->pipelen -= msg->len;
filp->private_data = msg;
msg->copied = 0;
}
spin_unlock(&pipe->lock);
if (msg == NULL)
goto out_unlock;
}
/* NOTE: it is up to the callback to update msg->copied */
res = pipe->ops->upcall(filp, msg, buf, len);
if (res < 0 || msg->len == msg->copied) {
filp->private_data = NULL;
spin_lock(&pipe->lock);
list_del_init(&msg->list);
spin_unlock(&pipe->lock);
pipe->ops->destroy_msg(msg);
}
out_unlock:
inode_unlock(inode);
return res;
}
static ssize_t
rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = file_inode(filp);
int res;
inode_lock(inode);
res = -EPIPE;
if (RPC_I(inode)->pipe != NULL)
res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
inode_unlock(inode);
return res;
}
static unsigned int
rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
{
struct inode *inode = file_inode(filp);
struct rpc_inode *rpci = RPC_I(inode);
unsigned int mask = POLLOUT | POLLWRNORM;
poll_wait(filp, &rpci->waitq, wait);
inode_lock(inode);
if (rpci->pipe == NULL)
mask |= POLLERR | POLLHUP;
else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
mask |= POLLIN | POLLRDNORM;
inode_unlock(inode);
return mask;
}
static long
rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct rpc_pipe *pipe;
int len;
switch (cmd) {
case FIONREAD:
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL) {
inode_unlock(inode);
return -EPIPE;
}
spin_lock(&pipe->lock);
len = pipe->pipelen;
if (filp->private_data) {
struct rpc_pipe_msg *msg;
msg = filp->private_data;
len += msg->len - msg->copied;
}
spin_unlock(&pipe->lock);
inode_unlock(inode);
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;
rcu_read_lock();
seq_printf(m, "RPC server: %s\n",
rcu_dereference(clnt->cl_xprt)->servername);
seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
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));
rcu_read_unlock();
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;
};
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(inode);
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 %pd\n",
__FILE__, __func__, dentry);
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 void
init_pipe(struct rpc_pipe *pipe)
{
pipe->nreaders = 0;
pipe->nwriters = 0;
INIT_LIST_HEAD(&pipe->in_upcall);
INIT_LIST_HEAD(&pipe->in_downcall);
INIT_LIST_HEAD(&pipe->pipe);
pipe->pipelen = 0;
INIT_DELAYED_WORK(&pipe->queue_timeout,
rpc_timeout_upcall_queue);
pipe->ops = NULL;
spin_lock_init(&pipe->lock);
pipe->dentry = NULL;
}
void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
{
kfree(pipe);
}
EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
{
struct rpc_pipe *pipe;
pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
if (!pipe)
return ERR_PTR(-ENOMEM);
init_pipe(pipe);
pipe->ops = ops;
pipe->flags = flags;
return pipe;
}
EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private,
struct rpc_pipe *pipe)
{
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(d_inode(dentry));
rpci->private = private;
rpci->pipe = pipe;
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;
}
int rpc_rmdir(struct dentry *dentry)
{
struct dentry *parent;
struct inode *dir;
int error;
parent = dget_parent(dentry);
dir = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_PARENT);
error = __rpc_rmdir(dir, dentry);
inode_unlock(dir);
dput(parent);
return error;
}
EXPORT_SYMBOL_GPL(rpc_rmdir);
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 = d_inode(dentry);
rpc_close_pipes(inode);
return __rpc_unlink(dir, dentry);
}
static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
const char *name)
{
struct qstr q = QSTR_INIT(name, strlen(name));
struct dentry *dentry = d_hash_and_lookup(parent, &q);
if (!dentry) {
dentry = d_alloc(parent, &q);
if (!dentry)
return ERR_PTR(-ENOMEM);
}
if (d_really_is_negative(dentry))
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 = d_inode(parent);
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);
dentry = d_hash_and_lookup(parent, &name);
if (dentry == NULL)
continue;
if (d_really_is_negative(dentry))
goto next;
switch (d_inode(dentry)->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 = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_CHILD);
__rpc_depopulate(parent, files, start, eof);
inode_unlock(dir);
}
static int rpc_populate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof,
void *private)
{
struct inode *dir = d_inode(parent);
struct dentry *dentry;
int i, err;
inode_lock(dir);
for (i = start; i < eof; i++) {
dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
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;
}
inode_unlock(dir);
return 0;
out_bad:
__rpc_depopulate(parent, files, start, eof);
inode_unlock(dir);
printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
__FILE__, __func__, parent);
return err;
}
static struct dentry *rpc_mkdir_populate(struct dentry *parent,
const char *name, umode_t mode, void *private,
int (*populate)(struct dentry *, void *), void *args_populate)
{
struct dentry *dentry;
struct inode *dir = d_inode(parent);
int error;
inode_lock_nested(dir, 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:
inode_unlock(dir);
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 = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_PARENT);
if (depopulate != NULL)
depopulate(dentry);
error = __rpc_rmdir(dir, dentry);
inode_unlock(dir);
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
* @pipe: &rpc_pipe containing input parameters
*
* 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_inode(file))->private.
*/
struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
void *private, struct rpc_pipe *pipe)
{
struct dentry *dentry;
struct inode *dir = d_inode(parent);
umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
int err;
if (pipe->ops->upcall == NULL)
umode &= ~S_IRUGO;
if (pipe->ops->downcall == NULL)
umode &= ~S_IWUGO;
inode_lock_nested(dir, I_MUTEX_PARENT);
dentry = __rpc_lookup_create_exclusive(parent, name);
if (IS_ERR(dentry))
goto out;
err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
private, pipe);
if (err)
goto out_err;
out:
inode_unlock(dir);
return dentry;
out_err:
dentry = ERR_PTR(err);
printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
__FILE__, __func__, parent, name,
err);
goto out;
}
EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
/**
* 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 = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_PARENT);
error = __rpc_rmpipe(dir, dentry);
inode_unlock(dir);
dput(parent);
return error;
}
EXPORT_SYMBOL_GPL(rpc_unlink);
/**
* rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
* @pdh: pointer to struct rpc_pipe_dir_head
*/
void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
{
INIT_LIST_HEAD(&pdh->pdh_entries);
pdh->pdh_dentry = NULL;
}
EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
/**
* rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
* @pdo: pointer to struct rpc_pipe_dir_object
* @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
* @pdo_data: pointer to caller-defined data
*/
void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
const struct rpc_pipe_dir_object_ops *pdo_ops,
void *pdo_data)
{
INIT_LIST_HEAD(&pdo->pdo_head);
pdo->pdo_ops = pdo_ops;
pdo->pdo_data = pdo_data;
}
EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
static int
rpc_add_pipe_dir_object_locked(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
int ret = 0;
if (pdh->pdh_dentry)
ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
if (ret == 0)
list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
return ret;
}
static void
rpc_remove_pipe_dir_object_locked(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
if (pdh->pdh_dentry)
pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
list_del_init(&pdo->pdo_head);
}
/**
* rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @pdo: pointer to struct rpc_pipe_dir_object
*
*/
int
rpc_add_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
int ret = 0;
if (list_empty(&pdo->pdo_head)) {
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
mutex_unlock(&sn->pipefs_sb_lock);
}
return ret;
}
EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
/**
* rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @pdo: pointer to struct rpc_pipe_dir_object
*
*/
void
rpc_remove_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
if (!list_empty(&pdo->pdo_head)) {
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
mutex_unlock(&sn->pipefs_sb_lock);
}
}
EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
/**
* rpc_find_or_alloc_pipe_dir_object
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @match: match struct rpc_pipe_dir_object to data
* @alloc: allocate a new struct rpc_pipe_dir_object
* @data: user defined data for match() and alloc()
*
*/
struct rpc_pipe_dir_object *
rpc_find_or_alloc_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
int (*match)(struct rpc_pipe_dir_object *, void *),
struct rpc_pipe_dir_object *(*alloc)(void *),
void *data)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_pipe_dir_object *pdo;
mutex_lock(&sn->pipefs_sb_lock);
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
if (!match(pdo, data))
continue;
goto out;
}
pdo = alloc(data);
if (!pdo)
goto out;
rpc_add_pipe_dir_object_locked(net, pdh, pdo);
out:
mutex_unlock(&sn->pipefs_sb_lock);
return pdo;
}
EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
static void
rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
{
struct rpc_pipe_dir_object *pdo;
struct dentry *dir = pdh->pdh_dentry;
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
pdo->pdo_ops->create(dir, pdo);
}
static void
rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
{
struct rpc_pipe_dir_object *pdo;
struct dentry *dir = pdh->pdh_dentry;
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
pdo->pdo_ops->destroy(dir, pdo);
}
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: the parent of new directory
* @name: the name of 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_create_client_dir(struct dentry *dentry,
const char *name,
struct rpc_clnt *rpc_client)
{
struct dentry *ret;
ret = rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
rpc_clntdir_populate, rpc_client);
if (!IS_ERR(ret)) {
rpc_client->cl_pipedir_objects.pdh_dentry = ret;
rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
}
return ret;
}
/**
* rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
* @rpc_client: rpc_client for the pipe
*/
int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
{
struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
if (dentry == NULL)
return 0;
rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
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, const char *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_nfsd,
RPCAUTH_gssd,
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,
},
[RPCAUTH_nfsd] = {
.name = "nfsd",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
[RPCAUTH_gssd] = {
.name = "gssd",
.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 = QSTR_INIT(dir_name, strlen(dir_name));
return d_hash_and_lookup(sb->s_root, &dir);
}
EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
int rpc_pipefs_init_net(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
if (IS_ERR(sn->gssd_dummy))
return PTR_ERR(sn->gssd_dummy);
mutex_init(&sn->pipefs_sb_lock);
sn->pipe_version = -1;
return 0;
}
void rpc_pipefs_exit_net(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
rpc_destroy_pipe_data(sn->gssd_dummy);
}
/*
* 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);
WARN_ON(sn->pipefs_sb == NULL);
mutex_unlock(&sn->pipefs_sb_lock);
}
EXPORT_SYMBOL_GPL(rpc_put_sb_net);
static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
[0] = {
.name = "clntXX",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
},
};
static ssize_t
dummy_downcall(struct file *filp, const char __user *src, size_t len)
{
return -EINVAL;
}
static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = dummy_downcall,
};
/*
* Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
* that it will ever use this info to handle an upcall, but rpc.gssd expects
* that this file will be there and have a certain format.
*/
static int
rpc_show_dummy_info(struct seq_file *m, void *v)
{
seq_printf(m, "RPC server: %s\n", utsname()->nodename);
seq_printf(m, "service: foo (1) version 0\n");
seq_printf(m, "address: 127.0.0.1\n");
seq_printf(m, "protocol: tcp\n");
seq_printf(m, "port: 0\n");
return 0;
}
static int
rpc_dummy_info_open(struct inode *inode, struct file *file)
{
return single_open(file, rpc_show_dummy_info, NULL);
}
static const struct file_operations rpc_dummy_info_operations = {
.owner = THIS_MODULE,
.open = rpc_dummy_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct rpc_filelist gssd_dummy_info_file[] = {
[0] = {
.name = "info",
.i_fop = &rpc_dummy_info_operations,
.mode = S_IFREG | S_IRUSR,
},
};
/**
* rpc_gssd_dummy_populate - create a dummy gssd pipe
* @root: root of the rpc_pipefs filesystem
* @pipe_data: pipe data created when netns is initialized
*
* Create a dummy set of directories and a pipe that gssd can hold open to
* indicate that it is up and running.
*/
static struct dentry *
rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
{
int ret = 0;
struct dentry *gssd_dentry;
struct dentry *clnt_dentry = NULL;
struct dentry *pipe_dentry = NULL;
struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
strlen(files[RPCAUTH_gssd].name));
/* We should never get this far if "gssd" doesn't exist */
gssd_dentry = d_hash_and_lookup(root, &q);
if (!gssd_dentry)
return ERR_PTR(-ENOENT);
ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
if (ret) {
pipe_dentry = ERR_PTR(ret);
goto out;
}
q.name = gssd_dummy_clnt_dir[0].name;
q.len = strlen(gssd_dummy_clnt_dir[0].name);
clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
if (!clnt_dentry) {
pipe_dentry = ERR_PTR(-ENOENT);
goto out;
}
ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
if (ret) {
__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
pipe_dentry = ERR_PTR(ret);
goto out;
}
pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
if (IS_ERR(pipe_dentry)) {
__rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
}
out:
dput(clnt_dentry);
dput(gssd_dentry);
return pipe_dentry;
}
static void
rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
{
struct dentry *clnt_dir = pipe_dentry->d_parent;
struct dentry *gssd_dir = clnt_dir->d_parent;
__rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
__rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
__rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
dput(pipe_dentry);
}
static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
struct dentry *root, *gssd_dentry;
struct net *net = get_net(sb->s_fs_info);
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
int err;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = RPCAUTH_GSSMAGIC;
sb->s_op = &s_ops;
sb->s_d_op = &simple_dentry_operations;
sb->s_time_gran = 1;
inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
sb->s_root = root = d_make_root(inode);
if (!root)
return -ENOMEM;
if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
return -ENOMEM;
gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
if (IS_ERR(gssd_dentry)) {
__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
return PTR_ERR(gssd_dentry);
}
dprintk("RPC: sending pipefs MOUNT notification for net %p%s\n",
net, NET_NAME(net));
mutex_lock(&sn->pipefs_sb_lock);
sn->pipefs_sb = sb;
err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_MOUNT,
sb);
if (err)
goto err_depopulate;
mutex_unlock(&sn->pipefs_sb_lock);
return 0;
err_depopulate:
rpc_gssd_dummy_depopulate(gssd_dentry);
blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
sn->pipefs_sb = NULL;
__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
mutex_unlock(&sn->pipefs_sb_lock);
return err;
}
bool
gssd_running(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_pipe *pipe = sn->gssd_dummy;
return pipe->nreaders || pipe->nwriters;
}
EXPORT_SYMBOL_GPL(gssd_running);
static struct dentry *
rpc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct net *net = current->nsproxy->net_ns;
return mount_ns(fs_type, flags, data, net, net->user_ns, rpc_fill_super);
}
static 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);
if (sn->pipefs_sb != sb) {
mutex_unlock(&sn->pipefs_sb_lock);
goto out;
}
sn->pipefs_sb = NULL;
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);
mutex_unlock(&sn->pipefs_sb_lock);
out:
kill_litter_super(sb);
put_net(net);
}
static struct file_system_type rpc_pipe_fs_type = {
.owner = THIS_MODULE,
.name = "rpc_pipefs",
.mount = rpc_mount,
.kill_sb = rpc_kill_sb,
};
MODULE_ALIAS_FS("rpc_pipefs");
MODULE_ALIAS("rpc_pipefs");
static void
init_once(void *foo)
{
struct rpc_inode *rpci = (struct rpc_inode *) foo;
inode_init_once(&rpci->vfs_inode);
rpci->private = NULL;
rpci->pipe = NULL;
init_waitqueue_head(&rpci->waitq);
}
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|SLAB_ACCOUNT),
init_once);
if (!rpc_inode_cachep)
return -ENOMEM;
err = rpc_clients_notifier_register();
if (err)
goto err_notifier;
err = register_filesystem(&rpc_pipe_fs_type);
if (err)
goto err_register;
return 0;
err_register:
rpc_clients_notifier_unregister();
err_notifier:
kmem_cache_destroy(rpc_inode_cachep);
return err;
}
void unregister_rpc_pipefs(void)
{
rpc_clients_notifier_unregister();
kmem_cache_destroy(rpc_inode_cachep);
unregister_filesystem(&rpc_pipe_fs_type);
}