On Thu, 5 Mar 2009 20:16:14 -0500, David Shaw <dshaw@xxxxxxxxxxxxxxx> wrote: > If a filesystem being written to via NFS returns a short write count > (as opposed to an error) to nfsd, nfsd treats that as a success for > the entire write, rather than the short count that actually succeeded. > > For example, given a 8192 byte write, if the underlying filesystem > only writes 4096 bytes, nfsd will ack back to the nfs client that all > 8192 bytes were written. The nfs client does have retry logic for > short writes, but this is never called as the client is told the > complete write succeeded. ... > Here is a patch to properly return the short write count to the > client. [patch elided] I bring this to your attention so you may, if you choose, look into this further: Problem synopsis: An old client (running RHL 9 with kernel "2.4.20-43.9.legacy") attempts to seek on a file mounted over nfs. The operation fails with "Illegal seek" or "Input/Output error". The server is running Fedora 11 kernel-PAE-2.6.29.5-191.fc11.i686, which includes the short write patch. When this kernel is re-built without the short write patch, everything works as before. Detais are at https://bugzilla.redhat.com/show_bug.cgi?id=508174 Caveats: I am specifically referring to the patch file "linux-2.6-nfsd-report-short-writes.patch" as newly included in Fedora's file kernel-2.6.29.5-191.fc11.src.rpm . I can't vouch that that patch file is identical to what was posted to this list or merged for 2.6.30-rc1. (As an aside, in this case, the client was attempting a simple gcc compile and link. The failing programs (invoked by fcc) were the assember ("as)" and "ld".) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
