[mirror_ubuntu-bionic-kernel.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
 * XXX: how are we excluding truncate/invalidate here? Maybe need to lock
 * page?
 */
static int ncp_file_mmap_fault(struct vm_area_struct *area,
					struct vm_fault *vmf)
{
	struct file *file = area->vm_file;
	struct dentry *dentry = file->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	char *pg_addr;
	unsigned int already_read;
	unsigned int count;
	int bufsize;
	int pos; /* XXX: loff_t ? */

	/*
	 * ncpfs has nothing against high pages as long
	 * as recvmsg and memset works on it
	 */
	vmf->page = alloc_page(GFP_HIGHUSER);
	if (!vmf->page)
		return VM_FAULT_OOM;
	pg_addr = kmap(vmf->page);
	pos = vmf->pgoff << PAGE_SHIFT;

	count = PAGE_SIZE;
	/* 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(vmf->page);
	kunmap(vmf->page);

	/*
	 * If I understand ncp_read_kernel() properly, the above always
	 * fetches from the network, here the analogue of disk.
	 * -- wli
	 */
	count_vm_event(PGMAJFAULT);
	return VM_FAULT_MAJOR;
}

static struct vm_operations_struct ncp_file_mmap =
{
	.fault = ncp_file_mmap_fault,
};


/* 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_path.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
d0217ac0 NP	27	* XXX: how are we excluding truncate/invalidate here? Maybe need to lock
d0217ac0 NP	28	* page?
1da177e4	29	*/
d0217ac0 NP	30	static int ncp_file_mmap_fault(struct vm_area_struct *area,
d0217ac0 NP	31	struct vm_fault *vmf)
1da177e4 LT	32	{
1da177e4 LT	33	struct file *file = area->vm_file;
92e5baef	34	struct dentry *dentry = file->f_path.dentry;
1da177e4	35	struct inode *inode = dentry->d_inode;
1da177e4 LT	36	char *pg_addr;
	37	unsigned int already_read;
	38	unsigned int count;
	39	int bufsize;
d0217ac0	40	int pos; /* XXX: loff_t ? */
1da177e4	41
d0217ac0 NP	42	/*
	43	* ncpfs has nothing against high pages as long
	44	* as recvmsg and memset works on it
	45	*/
	46	vmf->page = alloc_page(GFP_HIGHUSER);
	47	if (!vmf->page)
	48	return VM_FAULT_OOM;
	49	pg_addr = kmap(vmf->page);
	50	pos = vmf->pgoff << PAGE_SHIFT;
1da177e4 LT	51
1da177e4 LT	52	count = PAGE_SIZE;
1da177e4 LT	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);
d0217ac0 NP	86	flush_dcache_page(vmf->page);
d0217ac0 NP	87	kunmap(vmf->page);
1da177e4 LT	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	*/
f8891e5e	94	count_vm_event(PGMAJFAULT);
d0217ac0	95	return VM_FAULT_MAJOR;
1da177e4 LT	96	}
	97
	98	static struct vm_operations_struct ncp_file_mmap =
	99	{
54cb8821	100	.fault = ncp_file_mmap_fault,
1da177e4 LT	101	};
	102
	103
	104	/* This is used for a general mmap of a ncp file */
	105	int ncp_mmap(struct file file, struct vm_area_struct vma)
	106	{
92e5baef	107	struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 LT	108
	109	DPRINTK("ncp_mmap: called\n");
	110
	111	if (!ncp_conn_valid(NCP_SERVER(inode)))
	112	return -EIO;
	113
	114	/* only PAGE_COW or read-only supported now */
	115	if (vma->vm_flags & VM_SHARED)
	116	return -EINVAL;
	117	/* we do not support files bigger than 4GB... We eventually
	118	supports just 4GB... */
	119	if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff
	120	> (1U << (32 - PAGE_SHIFT)))
	121	return -EFBIG;
	122
	123	vma->vm_ops = &ncp_file_mmap;
	124	file_accessed(file);
	125	return 0;
	126	}