Commit b069d94a authored Apr 01, 2009 by Andy Adamson Committed by Benny Halevy Jun 17, 2009

nfs41: schedule async session reset



Define a new session reset state which is set upon a sequence operation error
in both the sync and async error handlers.

Place all new requests and all but the last outstanding rpc on the
slot_tbl_waitq. Spawn the recovery thread when the last slot is free.
Call nfs4_proc_destroy_session, reinitialize the session, call
nfs4_proc_create_session, clear the session reset state, and wake up the next
task on the slot_tbl_waitq.

Return the nfs4_proc_destroy_session status to the session reclaimer and
check for NFS4ERR_BADSESSION and NFS4ERR_DEADSESSION. Other destroy session
errors should be handled in nfs4_proc_destroy_session where the call can
be retried with adjusted arguments.

Signed-off-by: Andy <Adamson&lt;andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
nfs41: make nfs4_wait_bit_killable public]
    nfs4_wait_bit_killable to be used by NFSv4.1 session recover logic.
Signed-off-by: Rahul Iyer <iyer@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: have create_session work on nfs_client]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: trigger the state manager for session reset]
    Replace the session reset state with the NFS4CLNT_SESSION_SETUP cl_state.
    Place all rpc tasks to sleep on the slot table waitqueue until the slot
    table is drained, then schedule state recovery and wait for it to complete.
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: remove nfs41_session_recovery [ch]
Replaced by using the nfs4_state_manager.
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: nfs4_wait_bit_killable only used locally]
[nfs41: keep nfs4_wait_bit_killable static]
[nfs41: keep const nfs_server in nfs4_handle_exception]
[nfs41: remove session parameter from nfs4_find_slot]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: resset the session from nfs41_setup_sequence]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

parent 4745e315

fs/nfs/nfs4proc.c

+34 −0

Original line number	Diff line number	Diff line
		@@ -423,6 +423,22 @@ out:
		return ret_id;
		}

		static int nfs4_recover_session(struct nfs4_session *session)
		{
		struct nfs_client *clp = session->clp;
		int ret;

		for (;;) {
		ret = nfs4_wait_clnt_recover(clp);
		if (ret != 0)
		return ret;
		if (!test_bit(NFS4CLNT_SESSION_SETUP, &clp->cl_state))
		break;
		nfs4_schedule_state_manager(clp);
		}
		return 0;
		}

		static int nfs41_setup_sequence(struct nfs4_session *session,
		struct nfs4_sequence_args *args,
		struct nfs4_sequence_res *res,
		@@ -431,6 +447,7 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
		{
		struct nfs4_slot *slot;
		struct nfs4_slot_table *tbl;
		int status = 0;
		u8 slotid;

		dprintk("--> %s\n", __func__);
		@@ -443,6 +460,23 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
		tbl = &session->fc_slot_table;

		spin_lock(&tbl->slot_tbl_lock);
		if (test_bit(NFS4CLNT_SESSION_SETUP, &session->clp->cl_state)) {
		if (tbl->highest_used_slotid != -1) {
		rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL);
		spin_unlock(&tbl->slot_tbl_lock);
		dprintk("<-- %s: Session reset: draining\n", __func__);
		return -EAGAIN;
		}

		/* The slot table is empty; start the reset thread */
		dprintk("%s Session Reset\n", __func__);
		spin_unlock(&tbl->slot_tbl_lock);
		status = nfs4_recover_session(session);
		if (status)
		return status;
		spin_lock(&tbl->slot_tbl_lock);
		}

		slotid = nfs4_find_slot(tbl, task);
		if (slotid == NFS4_MAX_SLOT_TABLE) {
		rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL);

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