android_kernel_motorola_sm6225/net/sunrpc/rpc_pipe.c
Alexey Dobriyan 51cc50685a SL*B: drop kmem cache argument from constructor
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres.  Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.

Non-trivial places are:
	arch/powerpc/mm/init_64.c
	arch/powerpc/mm/hugetlbpage.c

This is flag day, yes.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00

942 lines
22 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>
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);
}