Hi, thanks for your really quick reply. > The BUG tells that nilfs met a corrupted block during lookup of a > btree. > > Can you confirm which version of 2.6.31 kernel you were using? The problem was, I had compiled the kernel on the same partition that is corrupted now. Anyway, by modifying the line in btree.c, I was able to recover most files, including the kernel tarball. (Though something like 1000 files are inaccessible.) I still cannot figure out the exact release number, though, because I can't find any place in the kernel source where it is written down. It was a kernel from the Debian testing distribution, downloaded on October 24. All files in the tarball are dated September 10. Does that help? I had actually seen the post on www.nilfs.org about a file system corruption fix in nilfs 2.0.17, but when I downloaded the Linux source from Debian 3 weeks later, I thought for sure they would include the fix. I didn't know Debian testing was this far behind on critical bugfixes. > > (Unfortunately, it is executed even if I use the "ro" option on the > > Linux command line -- why?!) It happens during a sys_open call. If > > the entire stack trace helps, I could post that, too. > > Sounds weird.. I still don't understand why nilfs_cleanerd was started even if the root fs was mounted read-only, but with the patched nilfs, it became clear that a library required by nilfs_cleanerd was among the files that were inaccessible, and that's why crashed right away. If I mount the file system later instead (as a non-root FS), the mount operation actually completes; the kernel just crashes when I try to access some files (with an unpatched/older nilfs such as the one in the current Ubuntu release). > That's a good point. The BUG_ON call was replaced in 2.6.33-rc1 to > handle it as a filesystem error. Oh, I didn't realize that. > Unfortunately, the disk image is rarely-helpful from my experiences > since it's hard to track the cause from a corrupted state. OK, I sort of expected that it wouldn't help. Then again, since there is no practical way of reproducing the bug, I thought the end result might be the only thing one can analyze to find the bug. Well, I'm glad I'm not a file system developer. :-) Best regards, Sebastian Reichelt -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
