On Sun, Mar 13, 2005 at 12:04:27AM -0500, Trond Myklebust wrote: > lau den 12.03.2005 Klokka 03:56 (-0800) skreiv Junfeng Yang: > > Hi, > > > > We checked NFS on top of ext3 using FiSC (our file system model checker) > > and found a case where NFS stat cache can contain inconsistent entries. > > > > Basically, to trigger this inconsistency, just do the following steps: > > 1. create a file A1, write a few bytes to it, so A1 is 4 words > > 2. create a hard link A2, pointing to A1 > > 3. stat on A2. A2's size is 4 words > > 4. truncate A1 to a larger size, write a few bytes at the end. now it's > > 1031 words. > > 5. stat on A2. it's size is still 4 words, which should be 1031 words > > > > We have a test case to re-create this warning. You can download it at > > http://fisc.stanford.edu/bug16/crash.c. It includes some sudo commands > > to mount nfs partitions, which you might want to change according to your > > local settings. > > > > cat /etc/exports shows: > > /mnt/sbd0-export localhost(rw,sync) > > /mnt/sbd1-export localhost(rw,sync) > > > > Let me know if you have any problems reproducing the warning. We'd > > appreciate any confirmations/clarifications. > > > > This is a known problem. Turn off the (default - grrr) subtree checking > export option on the server, and it will all work properly. The subtree > checking option violates the NFS standards for filehandle generation in > so many ways, that it isn't even funny.
I can't find any documentation about this, but it seems like the same problem that has been causing me headaches lately; when I replace glibc from the server side of an nfsroot, the client has a couple of variously wrong reads before it sees the new files. If it breaks NFS so badly, why is it the default for the Linux NFS server? -- Daniel Jacobowitz CodeSourcery, LLC - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
