xref: /third_party/e2fsprogs/0037-libext2fs-fix-ext2fs_compare_generic_bmap-logic.patch

From b795c06d8a44f42cdffdf5aa9561ff8de20d78cc Mon Sep 17 00:00:00 2001
From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Date: Mon, 7 Nov 2022 17:50:50 +0530
Subject: libext2fs: fix ext2fs_compare_generic_bmap logic

Currently this function was not correctly comparing against the right
length of the bitmap. Also when we compare bitarray v/s rbtree bitmap
the value returned by ext2fs_test_generic_bmap() could be different in
these two implementations.  Hence only check against boolean value.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 lib/ext2fs/gen_bitmap64.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
index c860c10e..f7710afd 100644
--- a/lib/ext2fs/gen_bitmap64.c
+++ b/lib/ext2fs/gen_bitmap64.c
@@ -629,10 +629,14 @@ errcode_t ext2fs_compare_generic_bmap(errcode_t neq,
 	    (bm1->end != bm2->end))
 		return neq;
 
-	for (i = bm1->end - ((bm1->end - bm1->start) % 8); i <= bm1->end; i++)
-		if (ext2fs_test_generic_bmap(gen_bm1, i) !=
-		    ext2fs_test_generic_bmap(gen_bm2, i))
+	for (i = bm1->start; i < bm1->end; i++) {
+		int ret1, ret2;
+		ret1 = !!ext2fs_test_generic_bmap(gen_bm1, i);
+		ret2 = !!ext2fs_test_generic_bmap(gen_bm2, i);
+		if (ret1 != ret2) {
 			return neq;
+		}
+	}
 
 	return 0;
 }
-- 
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