Hello Al! Sami found in his testing a rather easy way to deadlock a system with corrupted filesystem: Just have a directory D and inside D a directory entry pointing to D itself (e.g. corrupt '.' directory entry to have other name). Then when you try to remove the corrupted directory entry system will deadlock because we will try to lock D both as a parent and a child. Generally, when the directory structure is corrupted so that cycles are created, our locking protocol is prone to deadlocks. This is somewhat unpleasant if you have a system where you allow mounting untrusted media. So my question is: Do we care? And if yes, how to best fix this? My naive idea would be that we could check in d_instantiate() whether we are creating a directory dentry and if yes, check that inode is not already attached to a directory hierarchy (i.e. effectively forbid directory hardlinks). But this might be a bit tricky given dentry aliases. So what are your thoughts? Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
