[net-next-2.6.git] / fs / ncpfs / mmap.c

/*
 *  mmap.c
 *
 *  Copyright (C) 1995, 1996 by Volker Lendecke
 *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
 *
 */

#include <linux/stat.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/shm.h>
#include <linux/errno.h>
#include <linux/mman.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/ncp_fs.h>

#include "ncplib_kernel.h"
#include <asm/uaccess.h>
#include <asm/system.h>

/*
 * Fill in the supplied page for mmap
 */
static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
				     unsigned long address, int *type)
{
	struct file *file = area->vm_file;
	struct dentry *dentry = file->f_dentry;
	struct inode *inode = dentry->d_inode;
	struct page* page;
	char *pg_addr;
	unsigned int already_read;
	unsigned int count;
	int bufsize;
	int pos;

	page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages
	           as long as recvmsg and memset works on it */
	if (!page)
		return page;
	pg_addr = kmap(page);
	address &= PAGE_MASK;
	pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT);

	count = PAGE_SIZE;
	if (address + PAGE_SIZE > area->vm_end) {
		count = area->vm_end - address;
	}
	/* what we can read in one go */
	bufsize = NCP_SERVER(inode)->buffer_size;

	already_read = 0;
	if (ncp_make_open(inode, O_RDONLY) >= 0) {
		while (already_read < count) {
			int read_this_time;
			int to_read;

			to_read = bufsize - (pos % bufsize);

			to_read = min_t(unsigned int, to_read, count - already_read);

			if (ncp_read_kernel(NCP_SERVER(inode),
				     NCP_FINFO(inode)->file_handle,
				     pos, to_read,
				     pg_addr + already_read,
				     &read_this_time) != 0) {
				read_this_time = 0;
			}
			pos += read_this_time;
			already_read += read_this_time;

			if (read_this_time < to_read) {
				break;
			}
		}
		ncp_inode_close(inode);

	}

	if (already_read < PAGE_SIZE)
		memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
	flush_dcache_page(page);
	kunmap(page);

	/*
	 * If I understand ncp_read_kernel() properly, the above always
	 * fetches from the network, here the analogue of disk.
	 * -- wli
	 */
	if (type)
		*type = VM_FAULT_MAJOR;
	inc_page_state(pgmajfault);
	return page;
}

static struct vm_operations_struct ncp_file_mmap =
{
	.nopage	= ncp_file_mmap_nopage,
};


/* This is used for a general mmap of a ncp file */
int ncp_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct inode *inode = file->f_dentry->d_inode;
	
	DPRINTK("ncp_mmap: called\n");

	if (!ncp_conn_valid(NCP_SERVER(inode)))
		return -EIO;

	/* only PAGE_COW or read-only supported now */
	if (vma->vm_flags & VM_SHARED)
		return -EINVAL;
	/* we do not support files bigger than 4GB... We eventually 
	   supports just 4GB... */
	if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff 
	   > (1U << (32 - PAGE_SHIFT)))
		return -EFBIG;

	vma->vm_ops = &ncp_file_mmap;
	file_accessed(file);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* mmap.c
	3	*
	4	* Copyright (C) 1995, 1996 by Volker Lendecke
	5	* Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
	6	*
	7	*/
	8
	9	#include <linux/stat.h>
	10	#include <linux/time.h>
	11	#include <linux/kernel.h>
	12	#include <linux/mm.h>
	13	#include <linux/shm.h>
	14	#include <linux/errno.h>
	15	#include <linux/mman.h>
	16	#include <linux/string.h>
	17	#include <linux/slab.h>
	18	#include <linux/fcntl.h>
	19	#include <linux/ncp_fs.h>
	20
	21	#include "ncplib_kernel.h"
	22	#include <asm/uaccess.h>
	23	#include <asm/system.h>
	24
	25	/*
	26	* Fill in the supplied page for mmap
	27	*/
	28	static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
	29	unsigned long address, int *type)
	30	{
	31	struct file *file = area->vm_file;
	32	struct dentry *dentry = file->f_dentry;
	33	struct inode *inode = dentry->d_inode;
	34	struct page* page;
	35	char *pg_addr;
	36	unsigned int already_read;
	37	unsigned int count;
	38	int bufsize;
	39	int pos;
	40
	41	page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages
	42	as long as recvmsg and memset works on it */
	43	if (!page)
	44	return page;
	45	pg_addr = kmap(page);
	46	address &= PAGE_MASK;
	47	pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT);
	48
	49	count = PAGE_SIZE;
	50	if (address + PAGE_SIZE > area->vm_end) {
	51	count = area->vm_end - address;
	52	}
	53	/* what we can read in one go */
	54	bufsize = NCP_SERVER(inode)->buffer_size;
	55
	56	already_read = 0;
	57	if (ncp_make_open(inode, O_RDONLY) >= 0) {
	58	while (already_read < count) {
	59	int read_this_time;
	60	int to_read;
	61
	62	to_read = bufsize - (pos % bufsize);
	63
	64	to_read = min_t(unsigned int, to_read, count - already_read);
65
66	if (ncp_read_kernel(NCP_SERVER(inode),
67	NCP_FINFO(inode)->file_handle,
68	pos, to_read,
69	pg_addr + already_read,
70	&read_this_time) != 0) {
71	read_this_time = 0;
72	}
73	pos += read_this_time;
74	already_read += read_this_time;
75
76	if (read_this_time < to_read) {
77	break;
78	}
79	}
80	ncp_inode_close(inode);
81
82	}
83
84	if (already_read < PAGE_SIZE)
85	memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
86	flush_dcache_page(page);
87	kunmap(page);
88
89	/*
90	* If I understand ncp_read_kernel() properly, the above always
91	* fetches from the network, here the analogue of disk.
92	* -- wli
93	*/
94	if (type)
95	*type = VM_FAULT_MAJOR;
96	inc_page_state(pgmajfault);
97	return page;
98	}
99
100	static struct vm_operations_struct ncp_file_mmap =
101	{
102	.nopage = ncp_file_mmap_nopage,
103	};
104
105
106	/* This is used for a general mmap of a ncp file */
107	int ncp_mmap(struct file file, struct vm_area_struct vma)
108	{
109	struct inode *inode = file->f_dentry->d_inode;
110
111	DPRINTK("ncp_mmap: called\n");
112
113	if (!ncp_conn_valid(NCP_SERVER(inode)))
114	return -EIO;
115
116	/* only PAGE_COW or read-only supported now */
117	if (vma->vm_flags & VM_SHARED)
118	return -EINVAL;
119	/* we do not support files bigger than 4GB... We eventually
120	supports just 4GB... */
121	if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff
122	> (1U << (32 - PAGE_SHIFT)))
123	return -EFBIG;
124
125	vma->vm_ops = &ncp_file_mmap;
126	file_accessed(file);
127	return 0;
128	}