On Fri, Jun 13, 2008 at 09:42:15PM +1000, NeilBrown wrote:
>
> OCFS2 can return -ERESTARTSYS from write requests (and possibly
> elsewhere) if there is a signal pending.
>
> If nfsd is shutdown (by sending a signal to each thread) while there
> is still an IO load from the client, each thread could handle one last
> request with a signal pending. This can result in -ERESTARTSYS
> which is not understood by nfserrno() and so is reflected back to
> the client as nfserr_io aka -EIO. This is wrong.
>
> Instead, interpret ERESTARTSYS to mean "don't send a reply".
> The client will resend and - if the server is restarted - the write will
> (hopefully) be successful and everyone will be happy.
Thanks, applied--with a trivial change:
>
> Signed-off-by: Neil Brown <neilb@xxxxxxx>
>
> ### Diffstat output
> ./fs/nfsd/nfsproc.c | 1 +
> 1 file changed, 1 insertion(+)
>
> ----
> Funny how the shortest patches sometimes have the longest
> descriptions.
I added this to the body of the patch description:
>
> The symptom that I narrowed down to this was:
> copy a large file via NFS to an OCFS2 filesystem, and restart
> the nfs server during the copy.
> The 'cp' might get an -EIO, and the file will be corrupted -
> presumably holes in the middle were writes appeared to fail.
On the grounds that someone might run across the same problem or need to
reproduce it for some reason, so a good, simple description of the case
that found it might help.
--b.
>
> diff .prev/fs/nfsd/nfsproc.c ./fs/nfsd/nfsproc.c
> --- .prev/fs/nfsd/nfsproc.c 2008-06-13 21:31:53.000000000 +1000
> +++ ./fs/nfsd/nfsproc.c 2008-06-13 21:31:57.000000000 +1000
> @@ -614,6 +614,7 @@ nfserrno (int errno)
> #endif
> { nfserr_stale, -ESTALE },
> { nfserr_jukebox, -ETIMEDOUT },
> + { nfserr_dropit, -ERESTARTSYS },
> { nfserr_dropit, -EAGAIN },
> { nfserr_dropit, -ENOMEM },
> { nfserr_badname, -ESRCH },
>
> ### Diffstat output
> ./fs/nfsd/nfsproc.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff .prev/fs/nfsd/nfsproc.c ./fs/nfsd/nfsproc.c
> --- .prev/fs/nfsd/nfsproc.c 2008-06-13 21:31:53.000000000 +1000
> +++ ./fs/nfsd/nfsproc.c 2008-06-13 21:31:57.000000000 +1000
> @@ -614,6 +614,7 @@ nfserrno (int errno)
> #endif
> { nfserr_stale, -ESTALE },
> { nfserr_jukebox, -ETIMEDOUT },
> + { nfserr_dropit, -ERESTARTSYS },
> { nfserr_dropit, -EAGAIN },
> { nfserr_dropit, -ENOMEM },
> { nfserr_badname, -ESRCH },
--
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