[PATCH] mm acct accounting fix

This patch fixes mm->total_vm and mm->locked_vm acctounting in case when
move_page_tables() fails inside move_vma().
Signed-Off-By: NKirill Korotaev <dev@sw.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

mm/mremap.c

@@ -224,6 +224,12 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 			split = 1;
 	}
 
+	/*
+	 * if we failed to move page tables we still do total_vm increment
+	 * since do_munmap() will decrement it by old_len == new_len
+	 */
+	mm->total_vm += new_len >> PAGE_SHIFT;
+
 	if (do_munmap(mm, old_addr, old_len) < 0) {
 		/* OOM: unable to split vma, just get accounts right */
 		vm_unacct_memory(excess >> PAGE_SHIFT);
@@ -237,7 +243,6 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 			vma->vm_next->vm_flags |= VM_ACCOUNT;
 	}
 
-	mm->total_vm += new_len >> PAGE_SHIFT;
 	__vm_stat_account(mm, vma->vm_flags, vma->vm_file, new_len>>PAGE_SHIFT);
 	if (vm_flags & VM_LOCKED) {
 		mm->locked_vm += new_len >> PAGE_SHIFT;