libext2fs: require cluster size == block_size when opening a !bigalloc fs

In ext2fs_open() check to make sure the cluster size superblock field
is the same as the block size field when the bigalloc feature is not
set.  This is necessary since we will start introducing calculations
based on the cluster size field.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index a20b923..f87c171 100644 (file)
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -239,6 +239,12 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
                retval = EXT2_ET_CORRUPT_SUPERBLOCK;
                goto cleanup;
        }
+       if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+                                       EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
+           (fs->super->s_log_block_size != fs->super->s_log_cluster_size)) {
+               retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+               goto cleanup;
+       }
        fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
        if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) {
                retval = EXT2_ET_CORRUPT_SUPERBLOCK;