On Wed, Feb 19, 2020 at 04:32:30PM -0500, J. Bruce Fields wrote:
> On Wed, Feb 19, 2020 at 03:52:15PM -0500, Scott Mayhew wrote:
> > Currently, nfsd4_encode_exchange_id() encodes the utsname nodename
> > string in the server_scope field. In a multi-host container
> > environemnt, if an nfsd container is restarted on a different host than
> > it was originally running on, clients will see a server_scope mismatch
> > and will not attempt to reclaim opens.
> >
> > Instead, set the server_scope while we're in a process context during
> > service startup, so we get the utsname nodename of the current process
> > and store that in nfsd_net.
>
> Thanks! Just one nit:
>
> > Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
> > ---
> > fs/nfsd/netns.h | 1 +
> > fs/nfsd/nfs4xdr.c | 3 ++-
> > fs/nfsd/nfssvc.c | 3 +++
> > 3 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> > index 2baf32311e00..c6d95700105e 100644
> > --- a/fs/nfsd/netns.h
> > +++ b/fs/nfsd/netns.h
> > @@ -172,6 +172,7 @@ struct nfsd_net {
> > unsigned int longest_chain_cachesize;
> >
> > struct shrinker nfsd_reply_cache_shrinker;
> > + char server_scope[UNX_MAXNODENAME+1];
> > };
> >
> > /* Simple check to find out if a given net was properly initialized */
> > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> > index 9761512674a0..209174ee431a 100644
> > --- a/fs/nfsd/nfs4xdr.c
> > +++ b/fs/nfsd/nfs4xdr.c
> > @@ -4005,10 +4005,11 @@ nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
> > int major_id_sz;
> > int server_scope_sz;
> > uint64_t minor_id = 0;
> > + struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
> >
> > major_id = utsname()->nodename;
> > major_id_sz = strlen(major_id);
>
> We should do this one too. I'll fix that up and apply if that's OK.
And then maybe "server_scope" isn't the best name for the variable any
more. Applying as below if you don't see any objection.--b.
commit 9eb54e92718a
Author: Scott Mayhew <smayhew@xxxxxxxxxx>
Date: Wed Feb 19 15:52:15 2020 -0500
nfsd: set the server_scope during service startup
Currently, nfsd4_encode_exchange_id() encodes the utsname nodename
string in the server_scope field. In a multi-host container
environemnt, if an nfsd container is restarted on a different host than
it was originally running on, clients will see a server_scope mismatch
and will not attempt to reclaim opens.
Instead, set the server_scope while we're in a process context during
service startup, so we get the utsname nodename of the current process
and store that in nfsd_net.
Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
[bfields: fix up major_id too]
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 2baf32311e00..09aa545825bd 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -172,6 +172,8 @@ struct nfsd_net {
unsigned int longest_chain_cachesize;
struct shrinker nfsd_reply_cache_shrinker;
+ /* utsname taken from the the process that starts the server */
+ char nfsd_name[UNX_MAXNODENAME+1];
};
/* Simple check to find out if a given net was properly initialized */
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 9761512674a0..ad38aed6f5c2 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4005,11 +4005,12 @@ nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
int major_id_sz;
int server_scope_sz;
uint64_t minor_id = 0;
+ struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
- major_id = utsname()->nodename;
- major_id_sz = strlen(major_id);
- server_scope = utsname()->nodename;
- server_scope_sz = strlen(server_scope);
+ major_id = nn->nfsd_name;
+ major_id_sz = strlen(nn->nfsd_name);
+ server_scope = nn->nfsd_name;
+ server_scope_sz = strlen(nn->nfsd_name);
p = xdr_reserve_space(xdr,
8 /* eir_clientid */ +
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 3b77b904212d..ca9fd348548b 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -749,6 +749,9 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
if (nrservs == 0 && nn->nfsd_serv == NULL)
goto out;
+ strlcpy(nn->nfsd_name, utsname()->nodename,
+ sizeof(nn->nfsd_name));
+
error = nfsd_create_serv(net);
if (error)
goto out;
