patch-1.3.7 linux/fs/smbfs/mmap.c

• Lines: 142
• Date: Sat Jul 1 19:00:18 1995
• Orig file: v1.3.6/linux/fs/smbfs/mmap.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.6/linux/fs/smbfs/mmap.c linux/fs/smbfs/mmap.c
@@ -0,0 +1,141 @@
+/*
+ *  mmap.c
+ *
+ *  Copyright (C) 1995 by Paal-Kr. Engstad and Volker Lendecke
+ *
+ */
+
+#include <linux/config.h>
+#ifdef MODULE
+#include <linux/module.h>
+#include <linux/version.h>
+#endif
+
+#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/smb_fs.h>
+#include <linux/fcntl.h>
+
+#include <asm/segment.h>
+#include <asm/system.h>
+
+/*
+ * Fill in the supplied page for mmap
+ */
+static unsigned long 
+smb_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 n;
+	int i;
+	int pos;
+
+	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 */
+	n = SMB_SERVER(inode)->max_xmit - SMB_HEADER_LEN - 5 * 2 - 3 - 10;
+
+        if (smb_make_open(inode, O_RDONLY) < 0) {
+                clear = PAGE_SIZE;
+        }
+        else
+        {
+        
+                for (i = 0; i < (PAGE_SIZE - clear); i += n) {
+                        int hunk, result;
+
+                        hunk = PAGE_SIZE - i;
+                        if (hunk > n)
+                                hunk = n;
+
+                        DDPRINTK("smb_file_mmap_nopage: reading\n");
+                        DDPRINTK("smb_file_mmap_nopage: pos = %d\n", pos);
+                        result = smb_proc_read(SMB_SERVER(inode),
+                                               SMB_FINFO(inode), pos, hunk,
+                                               (char *) (page + i), 0);
+                        DDPRINTK("smb_file_mmap_nopage: result= %d\n", result);
+                        if (result < 0)
+                                break;
+                        pos += result;
+                        if (result < n) {
+                                i += result;
+                                break;
+                        }
+                }
+        }
+
+	tmp = page + PAGE_SIZE;
+	while (clear--) {
+		*(char *)--tmp = 0;
+	}
+	return page;
+}
+
+struct vm_operations_struct smb_file_mmap = {
+	NULL,			/* open */
+	NULL,			/* close */
+	NULL,			/* unmap */
+	NULL,			/* protect */
+	NULL,			/* sync */
+	NULL,			/* advise */
+	smb_file_mmap_nopage,	/* nopage */
+	NULL,			/* wppage */
+	NULL,			/* swapout */
+	NULL,			/* swapin */
+};
+
+
+/* This is used for a general mmap of a smb file */
+int
+smb_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)
+{
+        DPRINTK("smb_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 = &smb_file_mmap;
+	return 0;
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-indent-level: 8
+ * c-brace-imaginary-offset: 0
+ * c-brace-offset: -8
+ * c-argdecl-indent: 8
+ * c-label-offset: -8
+ * c-continued-statement-offset: 8
+ * c-continued-brace-offset: 0
+ * End:
+ */