From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 26 May 2025 02:20:36 +0000 (-0400)
Subject: e2fsck: fix e2fsck -E unshare_blocks when there are no shared blocks
X-Git-Tag: archive/debian/1.47.2-2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=684da272a9ea2c9fbdd72f6b1dbe41e2b3e310c8;p=thirdparty%2Fe2fsprogs.git

e2fsck: fix e2fsck -E unshare_blocks when there are no shared blocks

If there are no shared blocks in a ext4 file system, e2fsck -E
unshare_blocks will not actually clear the shared_blocks feature flag
since e2fsck_pass1_dupblocks() is never called.  Fix this by adding a
check in e2fsck_pass1() to clear the shared blocks flag.

https://github.com/tytso/e2fsprogs/issues/218

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
(cherry picked from commit 707af4359e132bc415c3f6339f4ced9f23b28c0b)
---

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index eb73922d..e7d5d0ae 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -2169,6 +2169,11 @@ void e2fsck_pass1(e2fsck_t ctx)
 			fix_problem(ctx, PR_1_DUP_BLOCKS_PREENSTOP, &pctx);
 		}
 		e2fsck_pass1_dupblocks(ctx, block_buf);
+	} else if ((ctx->options & E2F_OPT_UNSHARE_BLOCKS) &&
+		   ext2fs_has_feature_shared_blocks(fs->super) &&
+		   !(ctx->options & E2F_OPT_NO)) {
+		ext2fs_clear_feature_shared_blocks(fs->super);
+		ext2fs_mark_super_dirty(fs);
 	}
 	ctx->flags |= E2F_FLAG_ALLOC_OK;
 endit: