summaryrefslogtreecommitdiff
path: root/fs/ncpfs/mmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ncpfs/mmap.c')
-rw-r--r--fs/ncpfs/mmap.c128
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;
+}