On Dec 26, 2011, at 2:20 AM, Andreas Dilger wrote: > While this is true in theory, it is not possible to have 2^32 groups per flex group. This would mean 2^32 block bitmaps and inode bitmaps in a single group, which is impossible. This patch is based on commit 503358ae "ext4: avoid divide by zero when trying to mount a corrupted file system", as I quote: "If s_log_groups_per_flex is greater than 31, then groups_per_flex will will overflow and cause a divide by zero error." The intent is to avoid oversized shift in that commit, because the behavior is undefined in C and may vary on different architectures. My understanding is that sbi->s_es->s_log_groups_per_flex needs a sanity check if it is read from a malicious or corrupted filesystem in ext4_fill_flex_info(), which is called from ext4_fill_super(). Did I miss anything? - xi-- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
