Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / ncpfs / mmap.c

diff --git a/kernel/fs/ncpfs/mmap.c b/kernel/fs/ncpfs/mmap.c
new file mode 100644 (file)
index 0000000..33b873b
--- /dev/null
+++ b/kernel/fs/ncpfs/mmap.c
@@ -0,0 +1,125 @@
+/*
+ *  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/gfp.h>
+#include <linux/mm.h>
+#include <linux/shm.h>
+#include <linux/errno.h>
+#include <linux/mman.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/memcontrol.h>
+
+#include <asm/uaccess.h>
+
+#include "ncp_fs.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 inode *inode = file_inode(area->vm_file);
+       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.
+        * -- nyc
+        */
+       count_vm_event(PGMAJFAULT);
+       mem_cgroup_count_vm_event(area->vm_mm, PGMAJFAULT);
+       return VM_FAULT_MAJOR;
+}
+
+static const 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_inode(file);
+       
+       ncp_dbg(1, "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_pages(vma) + vma->vm_pgoff
+          > (1U << (32 - PAGE_SHIFT)))
+               return -EFBIG;
+
+       vma->vm_ops = &ncp_file_mmap;
+       file_accessed(file);
+       return 0;
+}