/*
* 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);
}
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;
}
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