*
* started by Ingo Molnar, Copyright (C) 2002, 2003
*/
-
+#include <linux/backing-dev.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/file.h>
}
-/***
- * sys_remap_file_pages - remap arbitrary pages of a shared backing store
- * file within an existing vma.
+/**
+ * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma
* @start: start of the remapped virtual memory range
* @size: size of the remapped virtual memory range
- * @prot: new protection bits of the range
- * @pgoff: to be mapped page of the backing store file
+ * @prot: new protection bits of the range (see NOTE)
+ * @pgoff: to-be-mapped page of the backing store file
* @flags: 0 or MAP_NONBLOCKED - the later will cause no IO.
*
- * this syscall works purely via pagetables, so it's the most efficient
+ * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma
+ * (shared backing store file).
+ *
+ * This syscall works purely via pagetables, so it's the most efficient
* way to map the same (large) file into a given virtual window. Unlike
* mmap()/mremap() it does not create any new vmas. The new mappings are
* also safe across swapout.
*
- * NOTE: the 'prot' parameter right now is ignored, and the vma's default
- * protection is used. Arbitrary protections might be implemented in the
- * future.
+ * NOTE: the 'prot' parameter right now is ignored (but must be zero),
+ * and the vma's default protection is used. Arbitrary protections
+ * might be implemented in the future.
*/
asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
- unsigned long __prot, unsigned long pgoff, unsigned long flags)
+ unsigned long prot, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct address_space *mapping;
int err = -EINVAL;
int has_write_lock = 0;
- if (__prot)
+ if (prot)
return err;
/*
* Sanitize the syscall parameters:
if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
goto out;
- if (!vma->vm_flags & VM_CAN_NONLINEAR)
+ if (!(vma->vm_flags & VM_CAN_NONLINEAR))
goto out;
if (end <= start || start < vma->vm_start || end > vma->vm_end)
*/
if (mapping_cap_account_dirty(mapping)) {
unsigned long addr;
+ struct file *file = vma->vm_file;
flags &= MAP_NONBLOCK;
- addr = mmap_region(vma->vm_file, start, size,
+ get_file(file);
+ addr = mmap_region(file, start, size,
flags, vma->vm_flags, pgoff, 1);
+ fput(file);
if (IS_ERR_VALUE(addr)) {
err = addr;
} else {