Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b86ff981 authored by Jens Axboe's avatar Jens Axboe
Browse files

[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: default avatarJens Axboe <axboe@suse.de>
parent b0e6e962

fs/Kconfig

+0 −12
Original line number Diff line number Diff line
@@ -859,18 +859,6 @@ config RAMFS 
	  To compile this as a module, choose M here: the module will be called

	  ramfs.



config RELAYFS_FS

	tristate "Relayfs file system support"

	---help---

	  Relayfs is a high-speed data relay filesystem designed to provide

	  an efficient mechanism for tools and facilities to relay large

	  amounts of data from kernel space to user space.



	  To compile this code as a module, choose M here: the module will be

	  called relayfs.



	  If unsure, say N.



config CONFIGFS_FS

	tristate "Userspace-driven configuration filesystem (EXPERIMENTAL)"

	depends on EXPERIMENTAL

fs/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ obj-$(CONFIG_AUTOFS4_FS) += autofs4/ 
obj-$(CONFIG_ADFS_FS)		+= adfs/

obj-$(CONFIG_FUSE_FS)		+= fuse/

obj-$(CONFIG_UDF_FS)		+= udf/

obj-$(CONFIG_RELAYFS_FS)	+= relayfs/

obj-$(CONFIG_SUN_OPENPROMFS)	+= openpromfs/

obj-$(CONFIG_JFS_FS)		+= jfs/

obj-$(CONFIG_XFS_FS)		+= xfs/

fs/relayfs/Makefile

deleted100644 → 0
+0 −4
Original line number Diff line number Diff line 
obj-$(CONFIG_RELAYFS_FS) += relayfs.o



relayfs-y := relay.o inode.o buffers.o

fs/relayfs/buffers.c

deleted100644 → 0
+0 −190
Original line number Diff line number Diff line 
/*

 * RelayFS buffer management code.

 *

 * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp

 * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)

 *

 * This file is released under the GPL.

 */



#include <linux/module.h>

#include <linux/vmalloc.h>

#include <linux/mm.h>

#include <linux/relayfs_fs.h>

#include "relay.h"

#include "buffers.h"



/*

 * close() vm_op implementation for relayfs file mapping.

 */

static void relay_file_mmap_close(struct vm_area_struct *vma)

{

	struct rchan_buf *buf = vma->vm_private_data;

	buf->chan->cb->buf_unmapped(buf, vma->vm_file);

}



/*

 * nopage() vm_op implementation for relayfs file mapping.

 */

static struct page *relay_buf_nopage(struct vm_area_struct *vma,

				     unsigned long address,

				     int *type)

{

	struct page *page;

	struct rchan_buf *buf = vma->vm_private_data;

	unsigned long offset = address - vma->vm_start;



	if (address > vma->vm_end)

		return NOPAGE_SIGBUS; /* Disallow mremap */

	if (!buf)

		return NOPAGE_OOM;



	page = vmalloc_to_page(buf->start + offset);

	if (!page)

		return NOPAGE_OOM;

	get_page(page);



	if (type)

		*type = VM_FAULT_MINOR;



	return page;

}



/*

 * vm_ops for relay file mappings.

 */

static struct vm_operations_struct relay_file_mmap_ops = {

	.nopage = relay_buf_nopage,

	.close = relay_file_mmap_close,

};



/**

 *	relay_mmap_buf: - mmap channel buffer to process address space

 *	@buf: relay channel buffer

 *	@vma: vm_area_struct describing memory to be mapped

 *

 *	Returns 0 if ok, negative on error

 *

 *	Caller should already have grabbed mmap_sem.

 */

int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)

{

	unsigned long length = vma->vm_end - vma->vm_start;

	struct file *filp = vma->vm_file;



	if (!buf)

		return -EBADF;



	if (length != (unsigned long)buf->chan->alloc_size)

		return -EINVAL;



	vma->vm_ops = &relay_file_mmap_ops;

	vma->vm_private_data = buf;

	buf->chan->cb->buf_mapped(buf, filp);



	return 0;

}



/**

 *	relay_alloc_buf - allocate a channel buffer

 *	@buf: the buffer struct

 *	@size: total size of the buffer

 *

 *	Returns a pointer to the resulting buffer, NULL if unsuccessful

 */

static void *relay_alloc_buf(struct rchan_buf *buf, unsigned long size)

{

	void *mem;

	unsigned int i, j, n_pages;



	size = PAGE_ALIGN(size);

	n_pages = size >> PAGE_SHIFT;



	buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL);

	if (!buf->page_array)

		return NULL;



	for (i = 0; i < n_pages; i++) {

		buf->page_array[i] = alloc_page(GFP_KERNEL);

		if (unlikely(!buf->page_array[i]))

			goto depopulate;

	}

	mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL);

	if (!mem)

		goto depopulate;



	memset(mem, 0, size);

	buf->page_count = n_pages;

	return mem;



depopulate:

	for (j = 0; j < i; j++)

		__free_page(buf->page_array[j]);

	kfree(buf->page_array);

	return NULL;

}



/**

 *	relay_create_buf - allocate and initialize a channel buffer

 *	@alloc_size: size of the buffer to allocate

 *	@n_subbufs: number of sub-buffers in the channel

 *

 *	Returns channel buffer if successful, NULL otherwise

 */

struct rchan_buf *relay_create_buf(struct rchan *chan)

{

	struct rchan_buf *buf = kcalloc(1, sizeof(struct rchan_buf), GFP_KERNEL);

	if (!buf)

		return NULL;



	buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);

	if (!buf->padding)

		goto free_buf;



	buf->start = relay_alloc_buf(buf, chan->alloc_size);

	if (!buf->start)

		goto free_buf;



	buf->chan = chan;

	kref_get(&buf->chan->kref);

	return buf;



free_buf:

	kfree(buf->padding);

	kfree(buf);

	return NULL;

}



/**

 *	relay_destroy_buf - destroy an rchan_buf struct and associated buffer

 *	@buf: the buffer struct

 */

void relay_destroy_buf(struct rchan_buf *buf)

{

	struct rchan *chan = buf->chan;

	unsigned int i;



	if (likely(buf->start)) {

		vunmap(buf->start);

		for (i = 0; i < buf->page_count; i++)

			__free_page(buf->page_array[i]);

		kfree(buf->page_array);

	}

	kfree(buf->padding);

	kfree(buf);

	kref_put(&chan->kref, relay_destroy_channel);

}



/**

 *	relay_remove_buf - remove a channel buffer

 *

 *	Removes the file from the relayfs fileystem, which also frees the

 *	rchan_buf_struct and the channel buffer.  Should only be called from

 *	kref_put().

 */

void relay_remove_buf(struct kref *kref)

{

	struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);

	buf->chan->cb->remove_buf_file(buf->dentry);

	relay_destroy_buf(buf);

}

fs/relayfs/buffers.h

deleted100644 → 0
+0 −12
Original line number Diff line number Diff line 
#ifndef _BUFFERS_H

#define _BUFFERS_H



/* This inspired by rtai/shmem */

#define FIX_SIZE(x) (((x) - 1) & PAGE_MASK) + PAGE_SIZE



extern int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma);

extern struct rchan_buf *relay_create_buf(struct rchan *chan);

extern void relay_destroy_buf(struct rchan_buf *buf);

extern void relay_remove_buf(struct kref *kref);



#endif/* _BUFFERS_H */