When resizing past the point where the reserve inode has reserved space for the block group descriptors to expand, and resize2fs (in an offline resize) needs to move the allocation bitmaps and/or inode table around, it's possible for resize2fs to allocate over the MMP block, which would be bad. Prevent this from happening by reserving the MMP block as a file system metadata block (which it is) in resize2fs's accounting. Addresses-Debian-Bug: #984472 Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> --- resize/resize2fs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/resize/resize2fs.c b/resize/resize2fs.c index a0d08e5b..daaa3d49 100644 --- a/resize/resize2fs.c +++ b/resize/resize2fs.c @@ -1177,6 +1177,11 @@ static errcode_t mark_table_blocks(ext2_filsys fs, if (blk) ext2fs_mark_block_bitmap2(bmap, blk); } + /* Reserve the MMP block */ + if (ext2fs_has_feature_mmp(fs->super) && + fs->super->s_mmp_block > fs->super->s_first_data_block && + fs->super->s_mmp_block < ext2fs_blocks_count(fs->super)) + ext2fs_mark_block_bitmap2(bmap, fs->super->s_mmp_block); return 0; } -- 2.30.0
