mem: Remove pagemap2 mentions

This file was created for backward compatibility with
not-yet-patched kernel. Now we can remove it.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

kerndat.c

@@ -48,7 +48,7 @@ static int kerndat_get_shmemdev(void)
 }
 
 /*
- * Check whether pagemap2 reports soft dirty bit. Kernel has
+ * Check whether pagemap reports soft dirty bit. Kernel has
  * this functionality under CONFIG_MEM_SOFT_DIRTY option.
  */
 
@@ -68,24 +68,16 @@ int kerndat_get_dirty_track(void)
 		return ret;
 	}
 
-	pm2 = open("/proc/self/pagemap2", O_RDONLY);
-	if (pm2 < 0) {
-		/*
-		 * Kernel shows soft-dirty bits only if this soft-dirty
-		 * was at least once re-set. (this is to be removed in
-		 * a couple of kernel releases)
-		 */
-		do_task_reset_dirty_track(getpid());
-		pm2 = open("/proc/self/pagemap", O_RDONLY);
-	}
+	/*
+	 * Kernel shows soft-dirty bits only if this soft-dirty
+	 * was at least once re-set. (this is to be removed in
+	 * a couple of kernel releases)
+	 */
+	do_task_reset_dirty_track(getpid());
+	pm2 = open("/proc/self/pagemap", O_RDONLY);
 	if (pm2 < 0) {
+		pr_perror("Can't open pagemap file");
 		munmap(map, PAGE_SIZE);
-		if (errno == ENOENT) {
-			pr_info("No pagemap2 file\n");
-			return 0;
-		}
-
-		pr_perror("Can't open pagemap2 file");
 		return ret;
 	}
 

mem.c

@@ -335,15 +335,9 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 	if (!map)
 		goto out_snap;
 
-	ret = pagemap = open_proc(ctl->pid.real, "pagemap2");
-	if (ret < 0) {
-		if (errno != ENOENT)
-			goto out_free;
-
-		ret = pagemap = open_proc(ctl->pid.real, "pagemap");
-		if (ret < 0)
-			goto out_free;
-	}
+	ret = pagemap = open_proc(ctl->pid.real, "pagemap");
+	if (ret < 0)
+		goto out_free;
 
 	ret = -1;
 	pp = create_page_pipe(vma_area_list->priv_size / 2, pargs_iovs(args));