patch-1.3.53 linux/fs/ncpfs/mmap.c

• Lines: 147
• Date: Tue Jan 2 14:18:43 1996
• Orig file: v1.3.52/linux/fs/ncpfs/mmap.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.52/linux/fs/ncpfs/mmap.c linux/fs/ncpfs/mmap.c
@@ -0,0 +1,146 @@
+/*
+ *  mmap.c
+ *
+ *  Copyright (C) 1995 by Volker Lendecke
+ *
+ */
+
+#include <linux/stat.h>
+#include <linux/sched.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/malloc.h>
+#include <linux/fcntl.h>
+#include <linux/ncp_fs.h>
+
+#include "ncplib_kernel.h"
+#include <asm/segment.h>
+#include <asm/system.h>
+
+static inline int min(int a, int b)
+{
+	return a<b ? a : b;
+}
+
+/*
+ * Fill in the supplied page for mmap
+ */
+static unsigned long 
+ncp_file_mmap_nopage(struct vm_area_struct * area,
+		     unsigned long address, unsigned long page, int no_share)
+{
+	struct inode * inode = area->vm_inode;
+	unsigned int clear;
+	unsigned long tmp;
+	int bufsize;
+	int pos;
+	unsigned short fs;
+
+	address &= PAGE_MASK;
+	pos = address - area->vm_start + area->vm_offset;
+
+	clear = 0;
+	if (address + PAGE_SIZE > area->vm_end)
+	{
+		clear = address + PAGE_SIZE - area->vm_end;
+	}
+
+        /* what we can read in one go */
+	bufsize = NCP_SERVER(inode)->buffer_size;
+
+	fs = get_fs();
+	set_fs(get_ds());
+
+        if (ncp_make_open(inode, O_RDONLY) < 0)
+	{
+                clear = PAGE_SIZE;
+        }
+        else
+        {
+		int already_read = 0;
+		int count = PAGE_SIZE - clear;
+		int to_read;
+
+		while (already_read < count)
+		{
+			int read_this_time;
+
+			if ((pos % bufsize) != 0)
+			{
+				to_read = bufsize - (pos % bufsize);
+			}
+			else
+			{
+				to_read = bufsize;
+			}
+
+			to_read = min(to_read, count - already_read);
+
+			if (ncp_read(NCP_SERVER(inode),
+				     NCP_FINFO(inode)->file_handle,
+				     pos, to_read,
+				     (char *)(page + 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;
+			}
+		}
+
+        }
+
+	set_fs(fs);
+
+	tmp = page + PAGE_SIZE;
+	while (clear--) {
+		*(char *)--tmp = 0;
+	}
+	return page;
+}
+
+struct vm_operations_struct ncp_file_mmap = {
+	NULL,			/* open */
+	NULL,			/* close */
+	NULL,			/* unmap */
+	NULL,			/* protect */
+	NULL,			/* sync */
+	NULL,			/* advise */
+	ncp_file_mmap_nopage,	/* nopage */
+	NULL,			/* wppage */
+	NULL,			/* swapout */
+	NULL,			/* swapin */
+};
+
+
+/* This is used for a general mmap of a ncp file */
+int
+ncp_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)
+{
+        DPRINTK("ncp_mmap: called\n");
+
+        /* only PAGE_COW or read-only supported now */
+	if (vma->vm_flags & VM_SHARED)	
+		return -EINVAL;
+	if (!inode->i_sb || !S_ISREG(inode->i_mode))
+		return -EACCES;
+	if (!IS_RDONLY(inode)) {
+		inode->i_atime = CURRENT_TIME;
+		inode->i_dirt = 1;
+	}
+
+	vma->vm_inode = inode;
+	inode->i_count++;
+	vma->vm_ops = &ncp_file_mmap;
+	return 0;
+}