2011-05-09 21:14:56

by Weston Andros Adamson

[permalink] [raw]
Subject: RFC: use scope from exchange_id to skip reclaim

Hey all,

I'd like comments on this patch. I think that I'm right, but I'm not 100%
about calling nfs4_state_start_reclaim_nograce() when server scopes don't match.

Thoughts?

-dros



2011-05-09 21:14:56

by Weston Andros Adamson

[permalink] [raw]
Subject: [PATCH] NFS: use scope from exchange_id to skip reclaim

>From Section 8.4.2.1 of the rfc 5661 - We can determine if a RECLAIM_REBOOT
can be skipped if the "eir_server_scope" from the exchange_id proc differs from
previous calls.

Also, in the future server_scope will be useful for determining whether client
trunking is available
---
fs/nfs/nfs4_fs.h | 2 ++
fs/nfs/nfs4proc.c | 12 ++++++++++++
fs/nfs/nfs4state.c | 42 +++++++++++++++++++++++++++++++++++++++++-
fs/nfs/nfs4xdr.c | 8 +++++++-
include/linux/nfs_fs_sb.h | 3 +++
include/linux/nfs_xdr.h | 1 +
6 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index c4a6983..bfde1c1 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -48,6 +48,7 @@ enum nfs4_client_state {
NFS4CLNT_SESSION_RESET,
NFS4CLNT_RECALL_SLOT,
NFS4CLNT_LEASE_CONFIRM,
+ NFS4CLNT_SERVER_SCOPE_MISMATCH,
};

enum nfs4_session_state {
@@ -349,6 +350,7 @@ extern void nfs4_schedule_state_manager(struct nfs_client *);
extern void nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);
extern void nfs41_handle_recall_slot(struct nfs_client *clp);
+extern void nfs41_handle_server_scope(struct nfs_client *, struct server_scope **);
extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
extern void nfs4_copy_stateid(nfs4_stateid *, struct nfs4_state *, fl_owner_t, pid_t);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 69c0f3c..2e62974 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4793,9 +4793,21 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
init_utsname()->domainname,
clp->cl_rpcclient->cl_auth->au_flavor);

+ res.server_scope = kzalloc(sizeof(struct server_scope), GFP_KERNEL);
+ if (unlikely(!res.server_scope))
+ return -ENOMEM;
+
status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+
if (!status)
status = nfs4_check_cl_exchange_flags(clp->cl_exchange_flags);
+
+ if (!status)
+ nfs41_handle_server_scope(clp, &res.server_scope);
+
+ /* free if not consumed by nfs41_handle_server_scope() */
+ kfree(res.server_scope);
+
dprintk("<-- %s status= %d\n", __func__, status);
return status;
}
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 036f5ad..26b0780 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1619,6 +1619,39 @@ static void nfs4_set_lease_expired(struct nfs_client *clp, int status)
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
}

+static int
+nfs41_cmp_server_scope(struct server_scope *a, struct server_scope *b)
+{
+ int res;
+
+ res = memcmp(a->server_scope, b->server_scope,
+ min(a->server_scope_sz, b->server_scope_sz));
+
+ if (!res)
+ res = a->server_scope_sz - b->server_scope_sz;
+
+ return res;
+}
+
+void
+nfs41_handle_server_scope(struct nfs_client *clp,
+ struct server_scope **server_scopep)
+{
+ struct server_scope *server_scope = *server_scopep;
+
+ if (clp->server_scope) {
+ /* if same server_scope, do nothing */
+ if (!nfs41_cmp_server_scope(clp->server_scope, server_scope))
+ return;
+
+ set_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state);
+ kfree(clp->server_scope);
+ }
+
+ clp->server_scope = server_scope;
+ *server_scopep = NULL;
+}
+
static void nfs4_state_manager(struct nfs_client *clp)
{
int status = 0;
@@ -1639,7 +1672,14 @@ static void nfs4_state_manager(struct nfs_client *clp)
goto out_error;
}
clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
- set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+
+ if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH,
+ &clp->cl_state))
+ nfs4_state_start_reclaim_nograce(clp);
+ else
+ set_bit(NFS4CLNT_RECLAIM_REBOOT,
+ &clp->cl_state);
+
pnfs_destroy_all_layouts(clp);
}

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index c3ccd2c..09a19ca 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4909,11 +4909,17 @@ static int decode_exchange_id(struct xdr_stream *xdr,
if (unlikely(status))
return status;

- /* Throw away server_scope */
+ /* Save server_scope */
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;

+ if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+ return -EIO;
+
+ memcpy(res->server_scope->server_scope, dummy_str, dummy);
+ res->server_scope->server_scope_sz = dummy;
+
/* Throw away Implementation id array */
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 87694ca..baf72a4 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -16,6 +16,7 @@ struct nfs4_sequence_args;
struct nfs4_sequence_res;
struct nfs_server;
struct nfs4_minor_version_ops;
+struct server_scope;

/*
* The nfs_client identifies our client state to the server.
@@ -83,6 +84,8 @@ struct nfs_client {
#ifdef CONFIG_NFS_FSCACHE
struct fscache_cookie *fscache; /* client index cache cookie */
#endif
+
+ struct server_scope *server_scope; /* from exchange_id */
};

/*
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 890dce2..31d6df4 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1039,6 +1039,7 @@ struct server_scope {
struct nfs41_exchange_id_res {
struct nfs_client *client;
u32 flags;
+ struct server_scope *server_scope;
};

struct nfs41_create_session_args {
--
1.7.4.2