mke2fs: complain if bigalloc and hugefiles_align_disk is incompatible

If the starting partition offset is incompatible with the bigalloc
cluster size, complain and exit, instead of creating a file which
would have a logical to physical block mapping which breaks the
cluster alignment requirement.

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

diff --git a/misc/mk_hugefiles.c b/misc/mk_hugefiles.c
index c292ddc..8291f01 100644 (file)
--- a/misc/mk_hugefiles.c
+++ b/misc/mk_hugefiles.c
@@ -490,9 +490,18 @@ errcode_t mk_hugefiles(ext2_filsys fs, const char *device_name)
        t = get_string_from_profile(fs_types, "hugefiles_align", "0");
        align = parse_num_blocks2(t, fs->super->s_log_block_size);
        free(t);
-       if (get_bool_from_profile(fs_types, "hugefiles_align_disk", 0))
+       if (get_bool_from_profile(fs_types, "hugefiles_align_disk", 0)) {
                part_offset = get_partition_start(device_name) /
                        (fs->blocksize / 512);
+               if (part_offset % EXT2FS_CLUSTER_RATIO(fs)) {
+                       fprintf(stderr,
+                               _("Partition offset of %llu (%uk) blocks "
+                                 "not compatible with cluster size %u.\n"),
+                               part_offset, fs->blocksize,
+                               EXT2_CLUSTER_SIZE(fs->super));
+                       exit(1);
+               }
+       }
        num_blocks = round_up_align(num_blocks, align, 0);
        zero_hugefile = get_bool_from_profile(fs_types, "zero_hugefiles",
                                              zero_hugefile);