nfs41: add session setup to the state manager

At mount, nfs_alloc_client sets the cl_state NFS4CLNT_LEASE_EXPIRED bit
and nfs4_alloc_session sets the NFS4CLNT_SESSION_SETUP bit, so both bits are
set when nfs4_lookup_root calls nfs4_recover_expired_lease which schedules
the nfs4_state_manager and waits for it to complete.

Place the session setup after the clientid establishment in nfs4_state_manager
so that the session is setup right after the clientid has been established
without rescheduling the state manager.

Unlike nfsv4.0, the nfs_client struct is not ready to use until the session
has been established.  Postpone marking the nfs_client struct to NFS_CS_READY
until after a successful CREATE_SESSION call so that other threads cannot use
the client until the session is established.

If the EXCHANGE_ID call fails and the session has not been setup (the
NFS4CLNT_SESSION_SETUP bit is set), mark the client with the error and return.

If the session setup CREATE_SESSION call fails with NFS4ERR_STALE_CLIENTID
which could occur due to server reboot or network partition inbetween the
EXCHANGE_ID and CREATE_SESSION call, reset the NFS4CLNT_LEASE_EXPIRED and
NFS4CLNT_SESSION_SETUP bits and try again.

If the CREATE_SESSION call fails with other errors, mark the client with
the error and return.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

[nfs41: NFS_CS_SESSION_SETUP cl_cons_state for back channel setup]
  On session setup, the CREATE_SESSION reply races with the server back channel
  probe which needs to succeed to setup the back channel. Set a new
  cl_cons_state NFS_CS_SESSION_SETUP just prior to the CREATE_SESSION call
  and add it as a valid state to nfs_find_client so that the client back channel
  can find the nfs_client struct and won't drop the server backchannel probe.
  Use a new cl_cons_state so that NFSv4.0 back channel behaviour which only
  sets NFS_CS_READY is unchanged.
  Adjust waiting on the nfs_client_active_wq accordingly.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

[nfs41: rename NFS_CS_SESSION_SETUP to NFS_CS_SESSION_INITING]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: set NFS_CL_SESSION_INITING in alloc_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: move session setup into a function]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[moved nfs4_proc_create_session declaration here]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index f62bc522615..f3b310e8ea0 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -100,6 +100,7 @@ extern void nfs_free_server(struct nfs_server *server);
 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 					   struct nfs_fh *,
 					   struct nfs_fattr *);
+extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 #ifdef CONFIG_PROC_FS
 extern int __init nfs_fs_proc_init(void);
 extern void nfs_fs_proc_exit(void);