On Fri, 24 Feb 2012 16:11:29 +0530 Nageswara R Sastry <rnsas...@linux.vnet.ibm.com> wrote:
> Hello, > > While working with 'fsfuzz - file system fuzzing tool' on 'btrfs' > encountered the following kernel bug. I inquired about robustness a while ago and it seems it's at some point on the horizon, but not now. My concern was about hot-unplugged disk drives, but btrfs also doesn't appreciate meta-data corruption. btrfs-raid users could be concerned, because contrarily to on a real RAID, the btrfs meta-data is a potential weak link. At some point, I would appreciate some kind of thorough evaluation using a fuzzer on small disk images. The btrfs developers could for instance: - provide a script to create a filesystem image with a known layout (known corpus) - provide .config and reference to kernel sources to build the kernel - provide a minimal root filesystem to be run under qemu, it would run a procedure on the other disk image at boot crashes wouldn't affect the host, which is good. - provide a way to retrieve the test parameters and results for every test case in case of bug, the test can be reproduced by the developers since the configuration is known - expect volunteers to run the scenarios (I know I would) The tricky part is of course the potentially super-costly procedure... Simplest case: flipping every bit / writing blocks with pseudo-random data, even on meta-data only, as the outcome on data is supposed to be known. Smarter: flipping bits on every btrfs meta-data structure type at every possible logical location. The kind of stuff that would help all this could be something like Python bindings for a *btrfs library*. Helpful even for prototyping fsck stuff, making illustrations, etc. As of today, how are btrfs developers testing the filesystem implementation (except with xfstests) ? Best regards, -- cJ PS: don't be mistaken, I'm not asking for all that, just suggesting. My time goes to something else, but I do have sleepy computers at home, and they could help. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
