[PATCH] msync(): set PF_SYNCWRITE

Pass the "we are doing synchronous writes" hint down from msync().
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/msync.c

@@ -214,6 +214,9 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
 	struct vm_area_struct * vma;
 	int unmapped_error, error = -EINVAL;
 
+	if (flags & MS_SYNC)
+		current->flags |= PF_SYNCWRITE;
+
 	down_read(&current->mm->mmap_sem);
 	if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
 		goto out;
@@ -264,5 +267,6 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
 	}
 out:
 	up_read(&current->mm->mmap_sem);
+	current->flags &= ~PF_SYNCWRITE;
 	return error;
 }