On Mon, Dec 14, 2020 at 11:35:12PM -0700, Chris Murphy wrote: > Squashfs doesn't have error detection for its metadata or the data > contained in it. I'm not sure why you're having such a high success > rate. Whether lossy or lossless compression algorithms in images, my > experience it is only sometimes results in an error, often we just get > artifacts. i.e. a bit flip turns into multiple wrong bytes of image > data, sometimes an entire row of pixels gets obliterated (thousands). > It just depends on what gets hit. But maybe lzma, which is what xz is > based on and what's used in squashfs images currently, could be > particularly susceptible to bit flips translating into something > detectable. It seems so. I mean, I can do more than a thousand tests if it helps, but that was enough to convince _me_. > But also, we're not using unsquashfs for boot or installation. The > squashfs image is loop mounted and treated as a random access file > system. Decompression of blocks is on demand. So I guess the next thing is: what's the error handling when the kernel hits an uncompress error when reading a compressed squashfs on the fly? It'd be kind of exciting if it logs an error we could actually watch for and pop up a message saying "so, yeah, your USB stick is bad...." -- Matthew Miller <mattdm@xxxxxxxxxxxxxxxxx> Fedora Project Leader _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
