1 files changed, 128 insertions, 0 deletions

diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c
new file mode 100644
index 000000000000..52d60c3d8996
--- /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;
+}