[PATCH] relay: migrate from relayfs to a generic relay API

Original patch from Paul Mundt, sysfs parts removed by me since they
were broken.

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 0 insertions, 581 deletions

diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c
deleted file mode 100644
index 383523011aad..000000000000
--- a/fs/relayfs/inode.c
+++ /dev/null
@@ -1,581 +0,0 @@
-/*
- * VFS-related code for RelayFS, a high-speed data relay filesystem.
- *
- * Copyright (C) 2003-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
- * Copyright (C) 2003-2005 - Karim Yaghmour <karim@opersys.com>
- *
- * Based on ramfs, Copyright (C) 2002 - Linus Torvalds
- *
- * This file is released under the GPL.
- */
-
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/mount.h>
-#include <linux/pagemap.h>
-#include <linux/init.h>
-#include <linux/string.h>
-#include <linux/backing-dev.h>
-#include <linux/namei.h>
-#include <linux/poll.h>
-#include <linux/relayfs_fs.h>
-#include "relay.h"
-#include "buffers.h"
-
-#define RELAYFS_MAGIC			0xF0B4A981
-
-static struct vfsmount *		relayfs_mount;
-static int				relayfs_mount_count;
-
-static struct backing_dev_info		relayfs_backing_dev_info = {
-	.ra_pages	= 0,	/* No readahead */
-	.capabilities	= BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
-};
-
-static struct inode *relayfs_get_inode(struct super_block *sb,
-				       int mode,
- 				       struct file_operations *fops,
-				       void *data)
-{
-	struct inode *inode;
-
-	inode = new_inode(sb);
-	if (!inode)
-		return NULL;
-
-	inode->i_mode = mode;
-	inode->i_uid = 0;
-	inode->i_gid = 0;
-	inode->i_blksize = PAGE_CACHE_SIZE;
-	inode->i_blocks = 0;
-	inode->i_mapping->backing_dev_info = &relayfs_backing_dev_info;
-	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	switch (mode & S_IFMT) {
-	case S_IFREG:
-		inode->i_fop = fops;
-		if (data)
-			inode->u.generic_ip = data;
-		break;
-	case S_IFDIR:
-		inode->i_op = &simple_dir_inode_operations;
-		inode->i_fop = &simple_dir_operations;
-
-		/* directory inodes start off with i_nlink == 2 (for "." entry) */
-		inode->i_nlink++;
-		break;
-	default:
-		break;
-	}
-
-	return inode;
-}
-
-/**
- *	relayfs_create_entry - create a relayfs directory or file
- *	@name: the name of the file to create
- *	@parent: parent directory
- *	@mode: mode
- *	@fops: file operations to use for the file
- *	@data: user-associated data for this file
- *
- *	Returns the new dentry, NULL on failure
- *
- *	Creates a file or directory with the specifed permissions.
- */
-static struct dentry *relayfs_create_entry(const char *name,
-					   struct dentry *parent,
-					   int mode,
-					   struct file_operations *fops,
-					   void *data)
-{
-	struct dentry *d;
-	struct inode *inode;
-	int error = 0;
-
-	BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode)));
-
-	error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
-	if (error) {
-		printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
-		return NULL;
-	}
-
-	if (!parent && relayfs_mount && relayfs_mount->mnt_sb)
-		parent = relayfs_mount->mnt_sb->s_root;
-
-	if (!parent) {
-		simple_release_fs(&relayfs_mount, &relayfs_mount_count);
-		return NULL;
-	}
-
-	parent = dget(parent);
-	mutex_lock(&parent->d_inode->i_mutex);
-	d = lookup_one_len(name, parent, strlen(name));
-	if (IS_ERR(d)) {
-		d = NULL;
-		goto release_mount;
-	}
-
-	if (d->d_inode) {
-		d = NULL;
-		goto release_mount;
-	}
-
-	inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
-	if (!inode) {
-		d = NULL;
-		goto release_mount;
-	}
-
-	d_instantiate(d, inode);
-	dget(d);	/* Extra count - pin the dentry in core */
-
-	if (S_ISDIR(mode))
-		parent->d_inode->i_nlink++;
-
-	goto exit;
-
-release_mount:
-	simple_release_fs(&relayfs_mount, &relayfs_mount_count);
-
-exit:
-	mutex_unlock(&parent->d_inode->i_mutex);
-	dput(parent);
-	return d;
-}
-
-/**
- *	relayfs_create_file - create a file in the relay filesystem
- *	@name: the name of the file to create
- *	@parent: parent directory
- *	@mode: mode, if not specied the default perms are used
- *	@fops: file operations to use for the file
- *	@data: user-associated data for this file
- *
- *	Returns file dentry if successful, NULL otherwise.
- *
- *	The file will be created user r on behalf of current user.
- */
-struct dentry *relayfs_create_file(const char *name,
-				   struct dentry *parent,
-				   int mode,
-				   struct file_operations *fops,
-				   void *data)
-{
-	BUG_ON(!fops);
-
-	if (!mode)
-		mode = S_IRUSR;
-	mode = (mode & S_IALLUGO) | S_IFREG;
-
-	return relayfs_create_entry(name, parent, mode, fops, data);
-}
-
-/**
- *	relayfs_create_dir - create a directory in the relay filesystem
- *	@name: the name of the directory to create
- *	@parent: parent directory, NULL if parent should be fs root
- *
- *	Returns directory dentry if successful, NULL otherwise.
- *
- *	The directory will be created world rwx on behalf of current user.
- */
-struct dentry *relayfs_create_dir(const char *name, struct dentry *parent)
-{
-	int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
-	return relayfs_create_entry(name, parent, mode, NULL, NULL);
-}
-
-/**
- *	relayfs_remove - remove a file or directory in the relay filesystem
- *	@dentry: file or directory dentry
- *
- *	Returns 0 if successful, negative otherwise.
- */
-int relayfs_remove(struct dentry *dentry)
-{
-	struct dentry *parent;
-	int error = 0;
-
-	if (!dentry)
-		return -EINVAL;
-	parent = dentry->d_parent;
-	if (!parent)
-		return -EINVAL;
-
-	parent = dget(parent);
-	mutex_lock(&parent->d_inode->i_mutex);
-	if (dentry->d_inode) {
-		if (S_ISDIR(dentry->d_inode->i_mode))
-			error = simple_rmdir(parent->d_inode, dentry);
-		else
-			error = simple_unlink(parent->d_inode, dentry);
-		if (!error)
-			d_delete(dentry);
-	}
-	if (!error)
-		dput(dentry);
-	mutex_unlock(&parent->d_inode->i_mutex);
-	dput(parent);
-
-	if (!error)
-		simple_release_fs(&relayfs_mount, &relayfs_mount_count);
-
-	return error;
-}
-
-/**
- *	relayfs_remove_file - remove a file from relay filesystem
- *	@dentry: directory dentry
- *
- *	Returns 0 if successful, negative otherwise.
- */
-int relayfs_remove_file(struct dentry *dentry)
-{
-	return relayfs_remove(dentry);
-}
-
-/**
- *	relayfs_remove_dir - remove a directory in the relay filesystem
- *	@dentry: directory dentry
- *
- *	Returns 0 if successful, negative otherwise.
- */
-int relayfs_remove_dir(struct dentry *dentry)
-{
-	return relayfs_remove(dentry);
-}
-
-/**
- *	relay_file_open - open file op for relay files
- *	@inode: the inode
- *	@filp: the file
- *
- *	Increments the channel buffer refcount.
- */
-static int relay_file_open(struct inode *inode, struct file *filp)
-{
-	struct rchan_buf *buf = inode->u.generic_ip;
-	kref_get(&buf->kref);
-	filp->private_data = buf;
-
-	return 0;
-}
-
-/**
- *	relay_file_mmap - mmap file op for relay files
- *	@filp: the file
- *	@vma: the vma describing what to map
- *
- *	Calls upon relay_mmap_buf to map the file into user space.
- */
-static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
-{
-	struct rchan_buf *buf = filp->private_data;
-	return relay_mmap_buf(buf, vma);
-}
-
-/**
- *	relay_file_poll - poll file op for relay files
- *	@filp: the file
- *	@wait: poll table
- *
- *	Poll implemention.
- */
-static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
-{
-	unsigned int mask = 0;
-	struct rchan_buf *buf = filp->private_data;
-
-	if (buf->finalized)
-		return POLLERR;
-
-	if (filp->f_mode & FMODE_READ) {
-		poll_wait(filp, &buf->read_wait, wait);
-		if (!relay_buf_empty(buf))
-			mask |= POLLIN | POLLRDNORM;
-	}
-
-	return mask;
-}
-
-/**
- *	relay_file_release - release file op for relay files
- *	@inode: the inode
- *	@filp: the file
- *
- *	Decrements the channel refcount, as the filesystem is
- *	no longer using it.
- */
-static int relay_file_release(struct inode *inode, struct file *filp)
-{
-	struct rchan_buf *buf = filp->private_data;
-	kref_put(&buf->kref, relay_remove_buf);
-
-	return 0;
-}
-
-/**
- *	relay_file_read_consume - update the consumed count for the buffer
- */
-static void relay_file_read_consume(struct rchan_buf *buf,
-				    size_t read_pos,
-				    size_t bytes_consumed)
-{
-	size_t subbuf_size = buf->chan->subbuf_size;
-	size_t n_subbufs = buf->chan->n_subbufs;
-	size_t read_subbuf;
-
-	if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
-		relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-		buf->bytes_consumed = 0;
-	}
-
-	buf->bytes_consumed += bytes_consumed;
-	read_subbuf = read_pos / buf->chan->subbuf_size;
-	if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
-		if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
-		    (buf->offset == subbuf_size))
-			return;
-		relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-		buf->bytes_consumed = 0;
-	}
-}
-
-/**
- *	relay_file_read_avail - boolean, are there unconsumed bytes available?
- */
-static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
-{
-	size_t bytes_produced, bytes_consumed, write_offset;
-	size_t subbuf_size = buf->chan->subbuf_size;
-	size_t n_subbufs = buf->chan->n_subbufs;
-	size_t produced = buf->subbufs_produced % n_subbufs;
-	size_t consumed = buf->subbufs_consumed % n_subbufs;
-
-	write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
-
-	if (consumed > produced) {
-		if ((produced > n_subbufs) &&
-		    (produced + n_subbufs - consumed <= n_subbufs))
-			produced += n_subbufs;
-	} else if (consumed == produced) {
-		if (buf->offset > subbuf_size) {
-			produced += n_subbufs;
-			if (buf->subbufs_produced == buf->subbufs_consumed)
-				consumed += n_subbufs;
-		}
-	}
-
-	if (buf->offset > subbuf_size)
-		bytes_produced = (produced - 1) * subbuf_size + write_offset;
-	else
-		bytes_produced = produced * subbuf_size + write_offset;
-	bytes_consumed = consumed * subbuf_size + buf->bytes_consumed;
-
-	if (bytes_produced == bytes_consumed)
-		return 0;
-
-	relay_file_read_consume(buf, read_pos, 0);
-
-	return 1;
-}
-
-/**
- *	relay_file_read_subbuf_avail - return bytes available in sub-buffer
- */
-static size_t relay_file_read_subbuf_avail(size_t read_pos,
-					   struct rchan_buf *buf)
-{
-	size_t padding, avail = 0;
-	size_t read_subbuf, read_offset, write_subbuf, write_offset;
-	size_t subbuf_size = buf->chan->subbuf_size;
-
-	write_subbuf = (buf->data - buf->start) / subbuf_size;
-	write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
-	read_subbuf = read_pos / subbuf_size;
-	read_offset = read_pos % subbuf_size;
-	padding = buf->padding[read_subbuf];
-
-	if (read_subbuf == write_subbuf) {
-		if (read_offset + padding < write_offset)
-			avail = write_offset - (read_offset + padding);
-	} else
-		avail = (subbuf_size - padding) - read_offset;
-
-	return avail;
-}
-
-/**
- *	relay_file_read_start_pos - find the first available byte to read
- *
- *	If the read_pos is in the middle of padding, return the
- *	position of the first actually available byte, otherwise
- *	return the original value.
- */
-static size_t relay_file_read_start_pos(size_t read_pos,
-					struct rchan_buf *buf)
-{
-	size_t read_subbuf, padding, padding_start, padding_end;
-	size_t subbuf_size = buf->chan->subbuf_size;
-	size_t n_subbufs = buf->chan->n_subbufs;
-
-	read_subbuf = read_pos / subbuf_size;
-	padding = buf->padding[read_subbuf];
-	padding_start = (read_subbuf + 1) * subbuf_size - padding;
-	padding_end = (read_subbuf + 1) * subbuf_size;
-	if (read_pos >= padding_start && read_pos < padding_end) {
-		read_subbuf = (read_subbuf + 1) % n_subbufs;
-		read_pos = read_subbuf * subbuf_size;
-	}
-
-	return read_pos;
-}
-
-/**
- *	relay_file_read_end_pos - return the new read position
- */
-static size_t relay_file_read_end_pos(struct rchan_buf *buf,
-				      size_t read_pos,
-				      size_t count)
-{
-	size_t read_subbuf, padding, end_pos;
-	size_t subbuf_size = buf->chan->subbuf_size;
-	size_t n_subbufs = buf->chan->n_subbufs;
-
-	read_subbuf = read_pos / subbuf_size;
-	padding = buf->padding[read_subbuf];
-	if (read_pos % subbuf_size + count + padding == subbuf_size)
-		end_pos = (read_subbuf + 1) * subbuf_size;
-	else
-		end_pos = read_pos + count;
-	if (end_pos >= subbuf_size * n_subbufs)
-		end_pos = 0;
-
-	return end_pos;
-}
-
-/**
- *	relay_file_read - read file op for relay files
- *	@filp: the file
- *	@buffer: the userspace buffer
- *	@count: number of bytes to read
- *	@ppos: position to read from
- *
- *	Reads count bytes or the number of bytes available in the
- *	current sub-buffer being read, whichever is smaller.
- */
-static ssize_t relay_file_read(struct file *filp,
-			       char __user *buffer,
-			       size_t count,
-			       loff_t *ppos)
-{
-	struct rchan_buf *buf = filp->private_data;
-	struct inode *inode = filp->f_dentry->d_inode;
-	size_t read_start, avail;
-	ssize_t ret = 0;
-	void *from;
-
-	mutex_lock(&inode->i_mutex);
-	if(!relay_file_read_avail(buf, *ppos))
-		goto out;
-
-	read_start = relay_file_read_start_pos(*ppos, buf);
-	avail = relay_file_read_subbuf_avail(read_start, buf);
-	if (!avail)
-		goto out;
-
-	from = buf->start + read_start;
-	ret = count = min(count, avail);
-	if (copy_to_user(buffer, from, count)) {
-		ret = -EFAULT;
-		goto out;
-	}
-	relay_file_read_consume(buf, read_start, count);
-	*ppos = relay_file_read_end_pos(buf, read_start, count);
-out:
-	mutex_unlock(&inode->i_mutex);
-	return ret;
-}
-
-struct file_operations relay_file_operations = {
-	.open		= relay_file_open,
-	.poll		= relay_file_poll,
-	.mmap		= relay_file_mmap,
-	.read		= relay_file_read,
-	.llseek		= no_llseek,
-	.release	= relay_file_release,
-};
-
-static struct super_operations relayfs_ops = {
-	.statfs		= simple_statfs,
-	.drop_inode	= generic_delete_inode,
-};
-
-static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
-{
-	struct inode *inode;
-	struct dentry *root;
-	int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
-
-	sb->s_blocksize = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
-	sb->s_magic = RELAYFS_MAGIC;
-	sb->s_op = &relayfs_ops;
-	inode = relayfs_get_inode(sb, mode, NULL, NULL);
-
-	if (!inode)
-		return -ENOMEM;
-
-	root = d_alloc_root(inode);
-	if (!root) {
-		iput(inode);
-		return -ENOMEM;
-	}
-	sb->s_root = root;
-
-	return 0;
-}
-
-static struct super_block * relayfs_get_sb(struct file_system_type *fs_type,
-					   int flags, const char *dev_name,
-					   void *data)
-{
-	return get_sb_single(fs_type, flags, data, relayfs_fill_super);
-}
-
-static struct file_system_type relayfs_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "relayfs",
-	.get_sb		= relayfs_get_sb,
-	.kill_sb	= kill_litter_super,
-};
-
-static int __init init_relayfs_fs(void)
-{
-	return register_filesystem(&relayfs_fs_type);
-}
-
-static void __exit exit_relayfs_fs(void)
-{
-
-
-
-
-
-	unregister_filesystem(&relayfs_fs_type);
-}
-
-module_init(init_relayfs_fs)
-module_exit(exit_relayfs_fs)
-
-EXPORT_SYMBOL_GPL(relay_file_operations);
-EXPORT_SYMBOL_GPL(relayfs_create_dir);
-EXPORT_SYMBOL_GPL(relayfs_remove_dir);
-EXPORT_SYMBOL_GPL(relayfs_create_file);
-EXPORT_SYMBOL_GPL(relayfs_remove_file);
-
-MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
-MODULE_DESCRIPTION("Relay Filesystem");
-MODULE_LICENSE("GPL");
-