Commit 76db6d95 authored by Andy Adamson's avatar Andy Adamson Committed by Benny Halevy

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: default avatarAndy Adamson <andros@netapp.com>
Signed-off-by: default avatarBenny 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: default avatarAndy Adamson <andros@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>

[nfs41: rename NFS_CS_SESSION_SETUP to NFS_CS_SESSION_INITING]
Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
[nfs41: set NFS_CL_SESSION_INITING in alloc_session]
Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
[nfs41: move session setup into a function]
Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
[moved nfs4_proc_create_session declaration here]
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent ac72b7b3
......@@ -366,7 +366,8 @@ struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
/* Don't match clients that failed to initialise properly */
if (clp->cl_cons_state != NFS_CS_READY)
if (!(clp->cl_cons_state == NFS_CS_READY ||
clp->cl_cons_state == NFS_CS_SESSION_INITING))
continue;
/* Different NFS versions cannot share the same nfs_client */
......@@ -499,7 +500,7 @@ static struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_in
nfs_free_client(new);
error = wait_event_killable(nfs_client_active_wq,
clp->cl_cons_state != NFS_CS_INITING);
clp->cl_cons_state < NFS_CS_INITING);
if (error < 0) {
nfs_put_client(clp);
return ERR_PTR(-ERESTARTSYS);
......@@ -520,7 +521,7 @@ static struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_in
/*
* Mark a server as ready or failed
*/
static void nfs_mark_client_ready(struct nfs_client *clp, int state)
void nfs_mark_client_ready(struct nfs_client *clp, int state)
{
clp->cl_cons_state = state;
wake_up_all(&nfs_client_active_wq);
......@@ -1135,6 +1136,7 @@ static int nfs4_init_client(struct nfs_client *clp,
if (error < 0)
goto error;
if (!nfs4_has_session(clp))
nfs_mark_client_ready(clp, NFS_CS_READY);
return 0;
......
......@@ -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);
......
......@@ -44,6 +44,7 @@ enum nfs4_client_state {
NFS4CLNT_RECLAIM_REBOOT,
NFS4CLNT_RECLAIM_NOGRACE,
NFS4CLNT_DELEGRETURN,
NFS4CLNT_SESSION_SETUP,
};
/*
......@@ -208,6 +209,7 @@ extern int nfs4_setup_sequence(struct nfs_client *clp,
int cache_reply, struct rpc_task *task);
extern void nfs4_destroy_session(struct nfs4_session *session);
extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
extern int nfs4_proc_create_session(struct nfs_client *, int reset);
#else /* CONFIG_NFS_v4_1 */
static inline int nfs4_setup_sequence(struct nfs_client *clp,
struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
......
......@@ -4382,6 +4382,16 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
session = kzalloc(sizeof(struct nfs4_session), GFP_KERNEL);
if (!session)
return NULL;
set_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state);
/*
* The create session reply races with the server back
* channel probe. Mark the client NFS_CS_SESSION_INITING
* so that the client back channel can find the
* nfs_client struct
*/
clp->cl_cons_state = NFS_CS_SESSION_INITING;
tbl = &session->fc_slot_table;
spin_lock_init(&tbl->slot_tbl_lock);
rpc_init_wait_queue(&tbl->slot_tbl_waitq, "Slot table");
......
......@@ -1113,6 +1113,27 @@ static int nfs4_reclaim_lease(struct nfs_client *clp)
return status;
}
#ifdef CONFIG_NFS_V4_1
static int nfs4_initialize_session(struct nfs_client *clp)
{
int status;
status = nfs4_proc_create_session(clp, 0);
if (!status) {
nfs_mark_client_ready(clp, NFS_CS_READY);
} else if (status == -NFS4ERR_STALE_CLIENTID) {
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
set_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state);
} else {
nfs_mark_client_ready(clp, status);
}
return status;
}
#else /* CONFIG_NFS_V4_1 */
static int nfs4_initialize_session(struct nfs_client *clp) { return 0; }
#endif /* CONFIG_NFS_V4_1 */
static void nfs4_state_manager(struct nfs_client *clp)
{
int status = 0;
......@@ -1126,6 +1147,9 @@ static void nfs4_state_manager(struct nfs_client *clp)
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
if (status == -EAGAIN)
continue;
if (clp->cl_cons_state ==
NFS_CS_SESSION_INITING)
nfs_mark_client_ready(clp, status);
goto out_error;
}
clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
......@@ -1136,7 +1160,16 @@ static void nfs4_state_manager(struct nfs_client *clp)
if (status != 0)
continue;
}
/* Setup the session */
if (nfs4_has_session(clp) &&
test_and_clear_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state)) {
status = nfs4_initialize_session(clp);
if (status) {
if (status == -NFS4ERR_STALE_CLIENTID)
continue;
goto out_error;
}
}
/* First recover reboot state... */
if (test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
status = nfs4_do_reclaim(clp, &nfs4_reboot_recovery_ops);
......
......@@ -24,6 +24,7 @@ struct nfs_client {
int cl_cons_state; /* current construction state (-ve: init error) */
#define NFS_CS_READY 0 /* ready to be used */
#define NFS_CS_INITING 1 /* busy initialising */
#define NFS_CS_SESSION_INITING 2 /* busy initialising session */
unsigned long cl_res_state; /* NFS resources state */
#define NFS_CS_CALLBACK 1 /* - callback started */
#define NFS_CS_IDMAP 2 /* - idmap started */
......
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