1 files changed, 85 insertions, 0 deletions
diff --git a/fs/sysv/mmap.c b/fs/sysv/mmap.c
new file mode 100644
index 000000000..3ec3867a9
--- /dev/null
+++ b/fs/sysv/mmap.c
@@ -0,0 +1,85 @@
+/*
+ *  linux/fs/sysv/mmap.c
+ *
+ *  mm/memory.c, mm/mmap.c
+ *  Copyright (C) 1991, 1992, 1993  Linus Torvalds
+ *
+ *  nfs/mmap.c
+ *  Copyright (C) 1993  Jon Tombs
+ *
+ *  fs/msdos/mmap.c
+ *  Copyright (C) 1994  Jacques Gelinas
+ *
+ *  fs/sysv/mmap.c
+ *  Copyright (C) 1994  Bruno Haible
+ *
+ *  SystemV/Coherent mmap handling
+ */
+
+#include <asm/segment.h>
+
+#include <linux/fs.h>
+#include <linux/sysv_fs.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/malloc.h>
+
+/*
+ * Fill in the supplied page for mmap
+ */
+static unsigned long sysv_file_mmap_nopage (struct vm_area_struct * area,
+	unsigned long address, unsigned long page, int no_share)
+{
+	int remaining, count, old_fs;
+	struct file filp;
+
+	address &= PAGE_MASK;
+	/* prepare a file pointer */
+	filp.f_pos = address - area->vm_start + area->vm_offset;
+	filp.f_reada = 0;
+	remaining = area->vm_end - address;
+	if (remaining > PAGE_SIZE)
+		remaining = PAGE_SIZE;
+	/* read from the file. page is in kernel space, not user space. */
+	old_fs = get_fs(); set_fs(get_ds());
+	count = sysv_file_read (area->vm_inode, &filp, (char *)page, remaining);
+	set_fs(old_fs);
+	if (count < 0)
+		count = 0;	/* do nothing on I/O error ?? */
+	else
+		remaining -= count;
+	if (remaining > 0)
+		memset((char *)page + count, 0, remaining);
+	return page;
+}
+
+static struct vm_operations_struct sysv_file_mmap = {
+	NULL,			/* open */
+	NULL,			/* close */
+	sysv_file_mmap_nopage,	/* nopage */
+	NULL,			/* wppage */
+	NULL,			/* share */
+	NULL,			/* unmap */
+};
+
+int sysv_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)
+{
+	if (vma->vm_page_prot & PAGE_RW)	/* only PAGE_COW or read-only supported right now */
+		return -EINVAL;
+	if (vma->vm_offset & (inode->i_sb->s_blocksize - 1))
+		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 = &sysv_file_mmap;
+	return 0;
+}