1 files changed, 128 insertions, 0 deletions
diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c
new file mode 100644
index 0000000..52d60c3
--- /dev/null
+++ b/fs/ncpfs/mmap.c
@@ -0,0 +1,128 @@
+/*
+ *  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;
+}