nfs4state.c

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/*
 *  fs/nfs/nfs4state.c
 *
 *  Client-side XDR for NFSv4.
 *
 *  Copyright (c) 2002 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <[email protected]>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Implementation of the NFSv4 state model.  For the time being,
 * this is minimal, but will be made much more complex in a
 * subsequent patch.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/ratelimit.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>

#include <linux/sunrpc/clnt.h>

#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#include "pnfs.h"
#include "netns.h"

#define NFSDBG_FACILITY     NFSDBG_STATE

#define OPENOWNER_POOL_SIZE 8

const nfs4_stateid zero_stateid;
static DEFINE_MUTEX(nfs_clid_init_mutex);
static LIST_HEAD(nfs4_clientid_list);

int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
{
    struct nfs4_setclientid_res clid = {
        .clientid = clp->cl_clientid,
        .confirm = clp->cl_confirm,
    };
    unsigned short port;
    int status;
    struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);

    if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
        goto do_confirm;
    port = nn->nfs_callback_tcpport;
    if (clp->cl_addr.ss_family == AF_INET6)
        port = nn->nfs_callback_tcpport6;

    status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
    if (status != 0)
        goto out;
    clp->cl_clientid = clid.clientid;
    clp->cl_confirm = clid.confirm;
    set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
do_confirm:
    status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
    if (status != 0)
        goto out;
    clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
    nfs4_schedule_state_renewal(clp);
out:
    return status;
}

int nfs40_discover_server_trunking(struct nfs_client *clp,
                   struct nfs_client **result,
                   struct rpc_cred *cred)
{
    struct nfs4_setclientid_res clid = {
        .clientid = clp->cl_clientid,
        .confirm = clp->cl_confirm,
    };
    struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
    unsigned short port;
    int status;

    port = nn->nfs_callback_tcpport;
    if (clp->cl_addr.ss_family == AF_INET6)
        port = nn->nfs_callback_tcpport6;

    status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
    if (status != 0)
        goto out;
    clp->cl_clientid = clid.clientid;
    clp->cl_confirm = clid.confirm;

    status = nfs40_walk_client_list(clp, result, cred);
    switch (status) {
    case -NFS4ERR_STALE_CLIENTID:
        set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
    case 0:
        /* Sustain the lease, even if it's empty.  If the clientid4
         * goes stale it's of no use for trunking discovery. */
        nfs4_schedule_state_renewal(*result);
        break;
    }

out:
    return status;
}

struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
{
    struct rpc_cred *cred = NULL;

    if (clp->cl_machine_cred != NULL)
        cred = get_rpccred(clp->cl_machine_cred);
    return cred;
}

static void nfs4_clear_machine_cred(struct nfs_client *clp)
{
    struct rpc_cred *cred;

    spin_lock(&clp->cl_lock);
    cred = clp->cl_machine_cred;
    clp->cl_machine_cred = NULL;
    spin_unlock(&clp->cl_lock);
    if (cred != NULL)
        put_rpccred(cred);
}

static struct rpc_cred *
nfs4_get_renew_cred_server_locked(struct nfs_server *server)
{
    struct rpc_cred *cred = NULL;
    struct nfs4_state_owner *sp;
    struct rb_node *pos;

    for (pos = rb_first(&server->state_owners);
         pos != NULL;
         pos = rb_next(pos)) {
        sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
        if (list_empty(&sp->so_states))
            continue;
        cred = get_rpccred(sp->so_cred);
        break;
    }
    return cred;
}

struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
{
    struct rpc_cred *cred = NULL;
    struct nfs_server *server;

    /* Use machine credentials if available */
    cred = nfs4_get_machine_cred_locked(clp);
    if (cred != NULL)
        goto out;

    rcu_read_lock();
    list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
        cred = nfs4_get_renew_cred_server_locked(server);
        if (cred != NULL)
            break;
    }
    rcu_read_unlock();

out:
    return cred;
}

#if defined(CONFIG_NFS_V4_1)

static int nfs41_setup_state_renewal(struct nfs_client *clp)
{
    int status;
    struct nfs_fsinfo fsinfo;

    if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
        nfs4_schedule_state_renewal(clp);
        return 0;
    }

    status = nfs4_proc_get_lease_time(clp, &fsinfo);
    if (status == 0) {
        /* Update lease time and schedule renewal */
        spin_lock(&clp->cl_lock);
        clp->cl_lease_time = fsinfo.lease_time * HZ;
        clp->cl_last_renewal = jiffies;
        spin_unlock(&clp->cl_lock);

        nfs4_schedule_state_renewal(clp);
    }

    return status;
}

/*
 * Back channel returns NFS4ERR_DELAY for new requests when
 * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
 * is ended.
 */
static void nfs4_end_drain_session(struct nfs_client *clp)
{
    struct nfs4_session *ses = clp->cl_session;
    struct nfs4_slot_table *tbl;
    int max_slots;

    if (ses == NULL)
        return;
    tbl = &ses->fc_slot_table;
    if (test_and_clear_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
        spin_lock(&tbl->slot_tbl_lock);
        max_slots = tbl->max_slots;
        while (max_slots--) {
            if (rpc_wake_up_first(&tbl->slot_tbl_waitq,
                        nfs4_set_task_privileged,
                        NULL) == NULL)
                break;
        }
        spin_unlock(&tbl->slot_tbl_lock);
    }
}

static int nfs4_wait_on_slot_tbl(struct nfs4_slot_table *tbl)
{
    spin_lock(&tbl->slot_tbl_lock);
    if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
        INIT_COMPLETION(tbl->complete);
        spin_unlock(&tbl->slot_tbl_lock);
        return wait_for_completion_interruptible(&tbl->complete);
    }
    spin_unlock(&tbl->slot_tbl_lock);
    return 0;
}

static int nfs4_begin_drain_session(struct nfs_client *clp)
{
    struct nfs4_session *ses = clp->cl_session;
    int ret = 0;

    set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
    /* back channel */
    ret = nfs4_wait_on_slot_tbl(&ses->bc_slot_table);
    if (ret)
        return ret;
    /* fore channel */
    return nfs4_wait_on_slot_tbl(&ses->fc_slot_table);
}

static void nfs41_finish_session_reset(struct nfs_client *clp)
{
    clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
    clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
    /* create_session negotiated new slot table */
    clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
    clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
    nfs41_setup_state_renewal(clp);
}

int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
{
    int status;

    if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
        goto do_confirm;
    nfs4_begin_drain_session(clp);
    status = nfs4_proc_exchange_id(clp, cred);
    if (status != 0)
        goto out;
    set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
do_confirm:
    status = nfs4_proc_create_session(clp, cred);
    if (status != 0)
        goto out;
    nfs41_finish_session_reset(clp);
    nfs_mark_client_ready(clp, NFS_CS_READY);
out:
    return status;
}

int nfs41_discover_server_trunking(struct nfs_client *clp,
                   struct nfs_client **result,
                   struct rpc_cred *cred)
{
    int status;

    status = nfs4_proc_exchange_id(clp, cred);
    if (status != NFS4_OK)
        return status;
    set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);

    return nfs41_walk_client_list(clp, result, cred);
}

struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp)
{
    struct rpc_cred *cred;

    spin_lock(&clp->cl_lock);
    cred = nfs4_get_machine_cred_locked(clp);
    spin_unlock(&clp->cl_lock);
    return cred;
}

#endif /* CONFIG_NFS_V4_1 */

static struct rpc_cred *
nfs4_get_setclientid_cred_server(struct nfs_server *server)
{
    struct nfs_client *clp = server->nfs_client;
    struct rpc_cred *cred = NULL;
    struct nfs4_state_owner *sp;
    struct rb_node *pos;

    spin_lock(&clp->cl_lock);
    pos = rb_first(&server->state_owners);
    if (pos != NULL) {
        sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
        cred = get_rpccred(sp->so_cred);
    }
    spin_unlock(&clp->cl_lock);
    return cred;
}

struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
{
    struct nfs_server *server;
    struct rpc_cred *cred;

    spin_lock(&clp->cl_lock);
    cred = nfs4_get_machine_cred_locked(clp);
    spin_unlock(&clp->cl_lock);
    if (cred != NULL)
        goto out;

    rcu_read_lock();
    list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
        cred = nfs4_get_setclientid_cred_server(server);
        if (cred != NULL)
            break;
    }
    rcu_read_unlock();

out:
    return cred;
}

static struct nfs4_state_owner *
nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
{
    struct rb_node **p = &server->state_owners.rb_node,
               *parent = NULL;
    struct nfs4_state_owner *sp;

    while (*p != NULL) {
        parent = *p;
        sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);

        if (cred < sp->so_cred)
            p = &parent->rb_left;
        else if (cred > sp->so_cred)
            p = &parent->rb_right;
        else {
            if (!list_empty(&sp->so_lru))
                list_del_init(&sp->so_lru);
            atomic_inc(&sp->so_count);
            return sp;
        }
    }
    return NULL;
}

static struct nfs4_state_owner *
nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
{
    struct nfs_server *server = new->so_server;
    struct rb_node **p = &server->state_owners.rb_node,
               *parent = NULL;
    struct nfs4_state_owner *sp;
    int err;

    while (*p != NULL) {
        parent = *p;
        sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);

        if (new->so_cred < sp->so_cred)
            p = &parent->rb_left;
        else if (new->so_cred > sp->so_cred)
            p = &parent->rb_right;
        else {
            if (!list_empty(&sp->so_lru))
                list_del_init(&sp->so_lru);
            atomic_inc(&sp->so_count);
            return sp;
        }
    }
    err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
    if (err)
        return ERR_PTR(err);
    rb_link_node(&new->so_server_node, parent, p);
    rb_insert_color(&new->so_server_node, &server->state_owners);
    return new;
}

static void
nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
{
    struct nfs_server *server = sp->so_server;

    if (!RB_EMPTY_NODE(&sp->so_server_node))
        rb_erase(&sp->so_server_node, &server->state_owners);
    ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
}

static void
nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
{
    sc->create_time = ktime_get();
    sc->flags = 0;
    sc->counter = 0;
    spin_lock_init(&sc->lock);
    INIT_LIST_HEAD(&sc->list);
    rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
}

static void
nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
{
    rpc_destroy_wait_queue(&sc->wait);
}

/*
 * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 * create a new state_owner.
 *
 */
static struct nfs4_state_owner *
nfs4_alloc_state_owner(struct nfs_server *server,
        struct rpc_cred *cred,
        gfp_t gfp_flags)
{
    struct nfs4_state_owner *sp;

    sp = kzalloc(sizeof(*sp), gfp_flags);
    if (!sp)
        return NULL;
    sp->so_server = server;
    sp->so_cred = get_rpccred(cred);
    spin_lock_init(&sp->so_lock);
    INIT_LIST_HEAD(&sp->so_states);
    nfs4_init_seqid_counter(&sp->so_seqid);
    atomic_set(&sp->so_count, 1);
    INIT_LIST_HEAD(&sp->so_lru);
    return sp;
}

static void
nfs4_drop_state_owner(struct nfs4_state_owner *sp)
{
    struct rb_node *rb_node = &sp->so_server_node;

    if (!RB_EMPTY_NODE(rb_node)) {
        struct nfs_server *server = sp->so_server;
        struct nfs_client *clp = server->nfs_client;

        spin_lock(&clp->cl_lock);
        if (!RB_EMPTY_NODE(rb_node)) {
            rb_erase(rb_node, &server->state_owners);
            RB_CLEAR_NODE(rb_node);
        }
        spin_unlock(&clp->cl_lock);
    }
}

static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
{
    nfs4_destroy_seqid_counter(&sp->so_seqid);
    put_rpccred(sp->so_cred);
    kfree(sp);
}

static void nfs4_gc_state_owners(struct nfs_server *server)
{
    struct nfs_client *clp = server->nfs_client;
    struct nfs4_state_owner *sp, *tmp;
    unsigned long time_min, time_max;
    LIST_HEAD(doomed);

    spin_lock(&clp->cl_lock);
    time_max = jiffies;
    time_min = (long)time_max - (long)clp->cl_lease_time;
    list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
        /* NB: LRU is sorted so that oldest is at the head */
        if (time_in_range(sp->so_expires, time_min, time_max))
            break;
        list_move(&sp->so_lru, &doomed);
        nfs4_remove_state_owner_locked(sp);
    }
    spin_unlock(&clp->cl_lock);

    list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
        list_del(&sp->so_lru);
        nfs4_free_state_owner(sp);
    }
}

struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
                          struct rpc_cred *cred,
                          gfp_t gfp_flags)
{
    struct nfs_client *clp = server->nfs_client;
    struct nfs4_state_owner *sp, *new;

    spin_lock(&clp->cl_lock);
    sp = nfs4_find_state_owner_locked(server, cred);
    spin_unlock(&clp->cl_lock);
    if (sp != NULL)
        goto out;
    new = nfs4_alloc_state_owner(server, cred, gfp_flags);
    if (new == NULL)
        goto out;
    do {
        if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
            break;
        spin_lock(&clp->cl_lock);
        sp = nfs4_insert_state_owner_locked(new);
        spin_unlock(&clp->cl_lock);
    } while (sp == ERR_PTR(-EAGAIN));
    if (sp != new)
        nfs4_free_state_owner(new);
out:
    nfs4_gc_state_owners(server);
    return sp;
}

void nfs4_put_state_owner(struct nfs4_state_owner *sp)
{
    struct nfs_server *server = sp->so_server;
    struct nfs_client *clp = server->nfs_client;

    if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
        return;

    sp->so_expires = jiffies;
    list_add_tail(&sp->so_lru, &server->state_owners_lru);
    spin_unlock(&clp->cl_lock);
}

void nfs4_purge_state_owners(struct nfs_server *server)
{
    struct nfs_client *clp = server->nfs_client;
    struct nfs4_state_owner *sp, *tmp;
    LIST_HEAD(doomed);

    spin_lock(&clp->cl_lock);
    list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
        list_move(&sp->so_lru, &doomed);
        nfs4_remove_state_owner_locked(sp);
    }
    spin_unlock(&clp->cl_lock);

    list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
        list_del(&sp->so_lru);
        nfs4_free_state_owner(sp);
    }
}

static struct nfs4_state *
nfs4_alloc_open_state(void)
{
    struct nfs4_state *state;

    state = kzalloc(sizeof(*state), GFP_NOFS);
    if (!state)
        return NULL;
    atomic_set(&state->count, 1);
    INIT_LIST_HEAD(&state->lock_states);
    spin_lock_init(&state->state_lock);
    seqlock_init(&state->seqlock);
    return state;
}

void
nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
{
    if (state->state == fmode)
        return;
    /* NB! List reordering - see the reclaim code for why.  */
    if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
        if (fmode & FMODE_WRITE)
            list_move(&state->open_states, &state->owner->so_states);
        else
            list_move_tail(&state->open_states, &state->owner->so_states);
    }
    state->state = fmode;
}

static struct nfs4_state *
__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
{
    struct nfs_inode *nfsi = NFS_I(inode);
    struct nfs4_state *state;

    list_for_each_entry(state, &nfsi->open_states, inode_states) {
        if (state->owner != owner)
            continue;
        if (atomic_inc_not_zero(&state->count))
            return state;
    }
    return NULL;
}

static void
nfs4_free_open_state(struct nfs4_state *state)
{
    kfree(state);
}

struct nfs4_state *
nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
{
    struct nfs4_state *state, *new;
    struct nfs_inode *nfsi = NFS_I(inode);

    spin_lock(&inode->i_lock);
    state = __nfs4_find_state_byowner(inode, owner);
    spin_unlock(&inode->i_lock);
    if (state)
        goto out;
    new = nfs4_alloc_open_state();
    spin_lock(&owner->so_lock);
    spin_lock(&inode->i_lock);
    state = __nfs4_find_state_byowner(inode, owner);
    if (state == NULL && new != NULL) {
        state = new;
        state->owner = owner;
        atomic_inc(&owner->so_count);
        list_add(&state->inode_states, &nfsi->open_states);
        ihold(inode);
        state->inode = inode;
        spin_unlock(&inode->i_lock);
        /* Note: The reclaim code dictates that we add stateless
         * and read-only stateids to the end of the list */
        list_add_tail(&state->open_states, &owner->so_states);
        spin_unlock(&owner->so_lock);
    } else {
        spin_unlock(&inode->i_lock);
        spin_unlock(&owner->so_lock);
        if (new)
            nfs4_free_open_state(new);
    }
out:
    return state;
}

void nfs4_put_open_state(struct nfs4_state *state)
{
    struct inode *inode = state->inode;
    struct nfs4_state_owner *owner = state->owner;

    if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
        return;
    spin_lock(&inode->i_lock);
    list_del(&state->inode_states);
    list_del(&state->open_states);
    spin_unlock(&inode->i_lock);
    spin_unlock(&owner->so_lock);
    iput(inode);
    nfs4_free_open_state(state);
    nfs4_put_state_owner(owner);
}

/*
 * Close the current file.
 */
static void __nfs4_close(struct nfs4_state *state,
        fmode_t fmode, gfp_t gfp_mask, int wait)
{
    struct nfs4_state_owner *owner = state->owner;
    int call_close = 0;
    fmode_t newstate;

    atomic_inc(&owner->so_count);
    /* Protect against nfs4_find_state() */
    spin_lock(&owner->so_lock);
    switch (fmode & (FMODE_READ | FMODE_WRITE)) {
        case FMODE_READ:
            state->n_rdonly--;
            break;
        case FMODE_WRITE:
            state->n_wronly--;
            break;
        case FMODE_READ|FMODE_WRITE:
            state->n_rdwr--;
    }
    newstate = FMODE_READ|FMODE_WRITE;
    if (state->n_rdwr == 0) {
        if (state->n_rdonly == 0) {
            newstate &= ~FMODE_READ;
            call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
            call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
        }
        if (state->n_wronly == 0) {
            newstate &= ~FMODE_WRITE;
            call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
            call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
        }
        if (newstate == 0)
            clear_bit(NFS_DELEGATED_STATE, &state->flags);
    }
    nfs4_state_set_mode_locked(state, newstate);
    spin_unlock(&owner->so_lock);

    if (!call_close) {
        nfs4_put_open_state(state);
        nfs4_put_state_owner(owner);
    } else
        nfs4_do_close(state, gfp_mask, wait);
}

void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
{
    __nfs4_close(state, fmode, GFP_NOFS, 0);
}

void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
{
    __nfs4_close(state, fmode, GFP_KERNEL, 1);
}

/*
 * Search the state->lock_states for an existing lock_owner
 * that is compatible with current->files
 */
static struct nfs4_lock_state *
__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
{
    struct nfs4_lock_state *pos;
    list_for_each_entry(pos, &state->lock_states, ls_locks) {
        if (type != NFS4_ANY_LOCK_TYPE && pos->ls_owner.lo_type != type)
            continue;
        switch (pos->ls_owner.lo_type) {
        case NFS4_POSIX_LOCK_TYPE:
            if (pos->ls_owner.lo_u.posix_owner != fl_owner)
                continue;
            break;
        case NFS4_FLOCK_LOCK_TYPE:
            if (pos->ls_owner.lo_u.flock_owner != fl_pid)
                continue;
        }
        atomic_inc(&pos->ls_count);
        return pos;
    }
    return NULL;
}

/*
 * Return a compatible lock_state. If no initialized lock_state structure
 * exists, return an uninitialized one.
 *
 */
static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
{
    struct nfs4_lock_state *lsp;
    struct nfs_server *server = state->owner->so_server;

    lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
    if (lsp == NULL)
        return NULL;
    nfs4_init_seqid_counter(&lsp->ls_seqid);
    atomic_set(&lsp->ls_count, 1);
    lsp->ls_state = state;
    lsp->ls_owner.lo_type = type;
    switch (lsp->ls_owner.lo_type) {
    case NFS4_FLOCK_LOCK_TYPE:
        lsp->ls_owner.lo_u.flock_owner = fl_pid;
        break;
    case NFS4_POSIX_LOCK_TYPE:
        lsp->ls_owner.lo_u.posix_owner = fl_owner;
        break;
    default:
        goto out_free;
    }
    lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
    if (lsp->ls_seqid.owner_id < 0)
        goto out_free;
    INIT_LIST_HEAD(&lsp->ls_locks);
    return lsp;
out_free:
    kfree(lsp);
    return NULL;
}

void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
{
    ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
    nfs4_destroy_seqid_counter(&lsp->ls_seqid);
    kfree(lsp);
}

/*
 * Return a compatible lock_state. If no initialized lock_state structure
 * exists, return an uninitialized one.
 *
 */
static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner, pid_t pid, unsigned int type)
{
    struct nfs4_lock_state *lsp, *new = NULL;
    
    for(;;) {
        spin_lock(&state->state_lock);
        lsp = __nfs4_find_lock_state(state, owner, pid, type);
        if (lsp != NULL)
            break;
        if (new != NULL) {
            list_add(&new->ls_locks, &state->lock_states);
            set_bit(LK_STATE_IN_USE, &state->flags);
            lsp = new;
            new = NULL;
            break;
        }
        spin_unlock(&state->state_lock);
        new = nfs4_alloc_lock_state(state, owner, pid, type);
        if (new == NULL)
            return NULL;
    }
    spin_unlock(&state->state_lock);
    if (new != NULL)
        nfs4_free_lock_state(state->owner->so_server, new);
    return lsp;
}

/*
 * Release reference to lock_state, and free it if we see that
 * it is no longer in use
 */
void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
{
    struct nfs4_state *state;

    if (lsp == NULL)
        return;
    state = lsp->ls_state;
    if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
        return;
    list_del(&lsp->ls_locks);
    if (list_empty(&state->lock_states))
        clear_bit(LK_STATE_IN_USE, &state->flags);
    spin_unlock(&state->state_lock);
    if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
        if (nfs4_release_lockowner(lsp) == 0)
            return;
    }
    nfs4_free_lock_state(lsp->ls_state->owner->so_server, lsp);
}

static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
{
    struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;

    dst->fl_u.nfs4_fl.owner = lsp;
    atomic_inc(&lsp->ls_count);
}

static void nfs4_fl_release_lock(struct file_lock *fl)
{
    nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
}

static const struct file_lock_operations nfs4_fl_lock_ops = {
    .fl_copy_lock = nfs4_fl_copy_lock,
    .fl_release_private = nfs4_fl_release_lock,
};

int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
{
    struct nfs4_lock_state *lsp;

    if (fl->fl_ops != NULL)
        return 0;
    if (fl->fl_flags & FL_POSIX)
        lsp = nfs4_get_lock_state(state, fl->fl_owner, 0, NFS4_POSIX_LOCK_TYPE);
    else if (fl->fl_flags & FL_FLOCK)
        lsp = nfs4_get_lock_state(state, NULL, fl->fl_pid,
                NFS4_FLOCK_LOCK_TYPE);
    else
        return -EINVAL;
    if (lsp == NULL)
        return -ENOMEM;
    fl->fl_u.nfs4_fl.owner = lsp;
    fl->fl_ops = &nfs4_fl_lock_ops;
    return 0;
}

static bool nfs4_copy_lock_stateid(nfs4_stateid *dst, struct nfs4_state *state,
        const struct nfs_lockowner *lockowner)
{
    struct nfs4_lock_state *lsp;
    fl_owner_t fl_owner;
    pid_t fl_pid;
    bool ret = false;


    if (lockowner == NULL)
        goto out;

    if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
        goto out;

    fl_owner = lockowner->l_owner;
    fl_pid = lockowner->l_pid;
    spin_lock(&state->state_lock);
    lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
    if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
        nfs4_stateid_copy(dst, &lsp->ls_stateid);
        ret = true;
    }
    spin_unlock(&state->state_lock);
    nfs4_put_lock_state(lsp);
out:
    return ret;
}

static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
{
    int seq;

    do {
        seq = read_seqbegin(&state->seqlock);
        nfs4_stateid_copy(dst, &state->stateid);
    } while (read_seqretry(&state->seqlock, seq));
}

/*
 * Byte-range lock aware utility to initialize the stateid of read/write
 * requests.
 */
void nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
        fmode_t fmode, const struct nfs_lockowner *lockowner)
{
    if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
        return;
    if (nfs4_copy_lock_stateid(dst, state, lockowner))
        return;
    nfs4_copy_open_stateid(dst, state);
}

struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
{
    struct nfs_seqid *new;

    new = kmalloc(sizeof(*new), gfp_mask);
    if (new != NULL) {
        new->sequence = counter;
        INIT_LIST_HEAD(&new->list);
        new->task = NULL;
    }
    return new;
}

void nfs_release_seqid(struct nfs_seqid *seqid)
{
    struct nfs_seqid_counter *sequence;

    if (list_empty(&seqid->list))
        return;
    sequence = seqid->sequence;
    spin_lock(&sequence->lock);
    list_del_init(&seqid->list);
    if (!list_empty(&sequence->list)) {
        struct nfs_seqid *next;

        next = list_first_entry(&sequence->list,
                struct nfs_seqid, list);
        rpc_wake_up_queued_task(&sequence->wait, next->task);
    }
    spin_unlock(&sequence->lock);
}

void nfs_free_seqid(struct nfs_seqid *seqid)
{
    nfs_release_seqid(seqid);
    kfree(seqid);
}

/*
 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 * failed with a seqid incrementing error -
 * see comments nfs_fs.h:seqid_mutating_error()
 */
static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
{
    BUG_ON(list_first_entry(&seqid->sequence->list, struct nfs_seqid, list) != seqid);
    switch (status) {
        case 0:
            break;
        case -NFS4ERR_BAD_SEQID:
            if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
                return;
            pr_warn_ratelimited("NFS: v4 server returned a bad"
                    " sequence-id error on an"
                    " unconfirmed sequence %p!\n",
                    seqid->sequence);
        case -NFS4ERR_STALE_CLIENTID:
        case -NFS4ERR_STALE_STATEID:
        case -NFS4ERR_BAD_STATEID:
        case -NFS4ERR_BADXDR:
        case -NFS4ERR_RESOURCE:
        case -NFS4ERR_NOFILEHANDLE:
            /* Non-seqid mutating errors */
            return;
    };
    /*
     * Note: no locking needed as we are guaranteed to be first
     * on the sequence list
     */
    seqid->sequence->counter++;
}

void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
{
    struct nfs4_state_owner *sp = container_of(seqid->sequence,
                    struct nfs4_state_owner, so_seqid);
    struct nfs_server *server = sp->so_server;

    if (status == -NFS4ERR_BAD_SEQID)
        nfs4_drop_state_owner(sp);
    if (!nfs4_has_session(server->nfs_client))
        nfs_increment_seqid(status, seqid);
}

/*
 * Increment the seqid if the LOCK/LOCKU succeeded, or
 * failed with a seqid incrementing error -
 * see comments nfs_fs.h:seqid_mutating_error()
 */
void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
{
    nfs_increment_seqid(status, seqid);
}

int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
{
    struct nfs_seqid_counter *sequence = seqid->sequence;
    int status = 0;

    spin_lock(&sequence->lock);
    seqid->task = task;
    if (list_empty(&seqid->list))
        list_add_tail(&seqid->list, &sequence->list);
    if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
        goto unlock;
    rpc_sleep_on(&sequence->wait, task, NULL);
    status = -EAGAIN;
unlock:
    spin_unlock(&sequence->lock);
    return status;
}

static int nfs4_run_state_manager(void *);

static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
{
    smp_mb__before_clear_bit();
    clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
    smp_mb__after_clear_bit();
    wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
    rpc_wake_up(&clp->cl_rpcwaitq);
}

/*
 * Schedule the nfs_client asynchronous state management routine
 */
void nfs4_schedule_state_manager(struct nfs_client *clp)
{
    struct task_struct *task;
    char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];

    if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
        return;
    __module_get(THIS_MODULE);
    atomic_inc(&clp->cl_count);

    /* The rcu_read_lock() is not strictly necessary, as the state
     * manager is the only thread that ever changes the rpc_xprt
     * after it's initialized.  At this point, we're single threaded. */
    rcu_read_lock();
    snprintf(buf, sizeof(buf), "%s-manager",
            rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
    rcu_read_unlock();
    task = kthread_run(nfs4_run_state_manager, clp, buf);
    if (IS_ERR(task)) {
        printk(KERN_ERR "%s: kthread_run: %ld\n",
            __func__, PTR_ERR(task));
        nfs4_clear_state_manager_bit(clp);
        nfs_put_client(clp);
        module_put(THIS_MODULE);
    }
}

/*
 * Schedule a lease recovery attempt
 */
void nfs4_schedule_lease_recovery(struct nfs_client *clp)
{
    if (!clp)
        return;
    if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
        set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
    dprintk("%s: scheduling lease recovery for server %s\n", __func__,
            clp->cl_hostname);
    nfs4_schedule_state_manager(clp);
}
EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);

/*
 * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
 * @clp: client to process
 *
 * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
 * resend of the SETCLIENTID and hence re-establish the
 * callback channel. Then return all existing delegations.
 */
static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
{
    set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
    nfs_expire_all_delegations(clp);
    dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
            clp->cl_hostname);
}

void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
{
    nfs40_handle_cb_pathdown(clp);
    nfs4_schedule_state_manager(clp);
}

static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
{

    set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
    /* Don't recover state that expired before the reboot */
    if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
        clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
        return 0;
    }
    set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
    set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
    return 1;
}

static int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
{
    set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
    clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
    set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
    set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
    return 1;
}

void nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
{
    struct nfs_client *clp = server->nfs_client;

    nfs4_state_mark_reclaim_nograce(clp, state);
    dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
            clp->cl_hostname);
    nfs4_schedule_state_manager(clp);
}
EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);

void nfs_inode_find_state_and_recover(struct inode *inode,
        const nfs4_stateid *stateid)
{
    struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
    struct nfs_inode *nfsi = NFS_I(inode);
    struct nfs_open_context *ctx;
    struct nfs4_state *state;
    bool found = false;

    spin_lock(&inode->i_lock);
    list_for_each_entry(ctx, &nfsi->open_files, list) {
        state = ctx->state;
        if (state == NULL)
            continue;
        if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
            continue;
        if (!nfs4_stateid_match(&state->stateid, stateid))
            continue;
        nfs4_state_mark_reclaim_nograce(clp, state);
        found = true;
    }
    spin_unlock(&inode->i_lock);
    if (found)
        nfs4_schedule_state_manager(clp);
}


static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
{
    struct inode *inode = state->inode;
    struct nfs_inode *nfsi = NFS_I(inode);
    struct file_lock *fl;
    int status = 0;

    if (inode->i_flock == NULL)
        return 0;

    /* Guard against delegation returns and new lock/unlock calls */
    down_write(&nfsi->rwsem);
    /* Protect inode->i_flock using the BKL */
    lock_flocks();
    for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
        if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
            continue;
        if (nfs_file_open_context(fl->fl_file)->state != state)
            continue;
        unlock_flocks();
        status = ops->recover_lock(state, fl);
        switch (status) {
            case 0:
                break;
            case -ESTALE:
            case -NFS4ERR_ADMIN_REVOKED:
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_BAD_STATEID:
            case -NFS4ERR_EXPIRED:
            case -NFS4ERR_NO_GRACE:
            case -NFS4ERR_STALE_CLIENTID:
            case -NFS4ERR_BADSESSION:
            case -NFS4ERR_BADSLOT:
            case -NFS4ERR_BAD_HIGH_SLOT:
            case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
                goto out;
            default:
                printk(KERN_ERR "NFS: %s: unhandled error %d. "
                    "Zeroing state\n", __func__, status);
            case -ENOMEM:
            case -NFS4ERR_DENIED:
            case -NFS4ERR_RECLAIM_BAD:
            case -NFS4ERR_RECLAIM_CONFLICT:
                /* kill_proc(fl->fl_pid, SIGLOST, 1); */
                status = 0;
        }
        lock_flocks();
    }
    unlock_flocks();
out:
    up_write(&nfsi->rwsem);
    return status;
}

static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
{
    struct nfs4_state *state;
    struct nfs4_lock_state *lock;
    int status = 0;

    /* Note: we rely on the sp->so_states list being ordered 
     * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
     * states first.
     * This is needed to ensure that the server won't give us any
     * read delegations that we have to return if, say, we are
     * recovering after a network partition or a reboot from a
     * server that doesn't support a grace period.
     */
restart:
    spin_lock(&sp->so_lock);
    list_for_each_entry(state, &sp->so_states, open_states) {
        if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
            continue;
        if (state->state == 0)
            continue;
        atomic_inc(&state->count);
        spin_unlock(&sp->so_lock);
        status = ops->recover_open(sp, state);
        if (status >= 0) {
            status = nfs4_reclaim_locks(state, ops);
            if (status >= 0) {
                spin_lock(&state->state_lock);
                list_for_each_entry(lock, &state->lock_states, ls_locks) {
                    if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
                        pr_warn_ratelimited("NFS: "
                            "%s: Lock reclaim "
                            "failed!\n", __func__);
                }
                spin_unlock(&state->state_lock);
                nfs4_put_open_state(state);
                goto restart;
            }
        }
        switch (status) {
            default:
                printk(KERN_ERR "NFS: %s: unhandled error %d. "
                    "Zeroing state\n", __func__, status);
            case -ENOENT:
            case -ENOMEM:
            case -ESTALE:
                /*
                 * Open state on this file cannot be recovered
                 * All we can do is revert to using the zero stateid.
                 */
                memset(&state->stateid, 0,
                    sizeof(state->stateid));
                /* Mark the file as being 'closed' */
                state->state = 0;
                break;
            case -EKEYEXPIRED:
                /*
                 * User RPCSEC_GSS context has expired.
                 * We cannot recover this stateid now, so
                 * skip it and allow recovery thread to
                 * proceed.
                 */
                break;
            case -NFS4ERR_ADMIN_REVOKED:
            case -NFS4ERR_STALE_STATEID:
            case -NFS4ERR_BAD_STATEID:
            case -NFS4ERR_RECLAIM_BAD:
            case -NFS4ERR_RECLAIM_CONFLICT:
                nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
                break;
            case -NFS4ERR_EXPIRED:
            case -NFS4ERR_NO_GRACE:
                nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
            case -NFS4ERR_STALE_CLIENTID:
            case -NFS4ERR_BADSESSION:
            case -NFS4ERR_BADSLOT:
            case -NFS4ERR_BAD_HIGH_SLOT:
            case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
                goto out_err;
        }
        nfs4_put_open_state(state);
        goto restart;
    }
    spin_unlock(&sp->so_lock);
    return 0;
out_err:
    nfs4_put_open_state(state);
    return status;
}

static void nfs4_clear_open_state(struct nfs4_state *state)
{
    struct nfs4_lock_state *lock;

    clear_bit(NFS_DELEGATED_STATE, &state->flags);
    clear_bit(NFS_O_RDONLY_STATE, &state->flags);
    clear_bit(NFS_O_WRONLY_STATE, &state->flags);
    clear_bit(NFS_O_RDWR_STATE, &state->flags);
    spin_lock(&state->state_lock);
    list_for_each_entry(lock, &state->lock_states, ls_locks) {
        lock->ls_seqid.flags = 0;
        clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
    }
    spin_unlock(&state->state_lock);
}

static void nfs4_reset_seqids(struct nfs_server *server,
    int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
{
    struct nfs_client *clp = server->nfs_client;
    struct nfs4_state_owner *sp;
    struct rb_node *pos;
    struct nfs4_state *state;

    spin_lock(&clp->cl_lock);
    for (pos = rb_first(&server->state_owners);
         pos != NULL;
         pos = rb_next(pos)) {
        sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
        sp->so_seqid.flags = 0;
        spin_lock(&sp->so_lock);
        list_for_each_entry(state, &sp->so_states, open_states) {
            if (mark_reclaim(clp, state))
                nfs4_clear_open_state(state);
        }
        spin_unlock(&sp->so_lock);
    }
    spin_unlock(&clp->cl_lock);
}

static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
    int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
{
    struct nfs_server *server;

    rcu_read_lock();
    list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
        nfs4_reset_seqids(server, mark_reclaim);
    rcu_read_unlock();
}

static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
{
    /* Mark all delegations for reclaim */
    nfs_delegation_mark_reclaim(clp);
    nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
}

static void nfs4_reclaim_complete(struct nfs_client *clp,
                 const struct nfs4_state_recovery_ops *ops)
{
    /* Notify the server we're done reclaiming our state */
    if (ops->reclaim_complete)
        (void)ops->reclaim_complete(clp);
}

static void nfs4_clear_reclaim_server(struct nfs_server *server)
{
    struct nfs_client *clp = server->nfs_client;
    struct nfs4_state_owner *sp;
    struct rb_node *pos;
    struct nfs4_state *state;

    spin_lock(&clp->cl_lock);
    for (pos = rb_first(&server->state_owners);
         pos != NULL;
         pos = rb_next(pos)) {
        sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
        spin_lock(&sp->so_lock);
        list_for_each_entry(state, &sp->so_states, open_states) {
            if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
                        &state->flags))
                continue;
            nfs4_state_mark_reclaim_nograce(clp, state);
        }
        spin_unlock(&sp->so_lock);
    }
    spin_unlock(&clp->cl_lock);
}

static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
{
    struct nfs_server *server;

    if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
        return 0;

    rcu_read_lock();
    list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
        nfs4_clear_reclaim_server(server);
    rcu_read_unlock();

    nfs_delegation_reap_unclaimed(clp);
    return 1;
}

static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
{
    if (!nfs4_state_clear_reclaim_reboot(clp))
        return;
    nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
}

static void nfs_delegation_clear_all(struct nfs_client *clp)
{
    nfs_delegation_mark_reclaim(clp);
    nfs_delegation_reap_unclaimed(clp);
}

static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
{
    nfs_delegation_clear_all(clp);
    nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
}

static void nfs4_warn_keyexpired(const char *s)
{
    printk_ratelimited(KERN_WARNING "Error: state manager"
            " encountered RPCSEC_GSS session"
            " expired against NFSv4 server %s.\n",
            s);
}

static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
{
    switch (error) {
        case 0:
            break;
        case -NFS4ERR_CB_PATH_DOWN:
            nfs40_handle_cb_pathdown(clp);
            break;
        case -NFS4ERR_NO_GRACE:
            nfs4_state_end_reclaim_reboot(clp);
            break;
        case -NFS4ERR_STALE_CLIENTID:
        case -NFS4ERR_LEASE_MOVED:
            set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
            nfs4_state_clear_reclaim_reboot(clp);
            nfs4_state_start_reclaim_reboot(clp);
            break;
        case -NFS4ERR_EXPIRED:
            set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
            nfs4_state_start_reclaim_nograce(clp);
            break;
        case -NFS4ERR_BADSESSION:
        case -NFS4ERR_BADSLOT:
        case -NFS4ERR_BAD_HIGH_SLOT:
        case -NFS4ERR_DEADSESSION:
        case -NFS4ERR_SEQ_FALSE_RETRY:
        case -NFS4ERR_SEQ_MISORDERED:
            set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
            /* Zero session reset errors */
            break;
        case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
            set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
            break;
        case -EKEYEXPIRED:
            /* Nothing we can do */
            nfs4_warn_keyexpired(clp->cl_hostname);
            break;
        default:
            dprintk("%s: failed to handle error %d for server %s\n",
                    __func__, error, clp->cl_hostname);
            return error;
    }
    dprintk("%s: handled error %d for server %s\n", __func__, error,
            clp->cl_hostname);
    return 0;
}

static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
{
    struct nfs4_state_owner *sp;
    struct nfs_server *server;
    struct rb_node *pos;
    int status = 0;

restart:
    rcu_read_lock();
    list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
        nfs4_purge_state_owners(server);
        spin_lock(&clp->cl_lock);
        for (pos = rb_first(&server->state_owners);
             pos != NULL;
             pos = rb_next(pos)) {
            sp = rb_entry(pos,
                struct nfs4_state_owner, so_server_node);
            if (!test_and_clear_bit(ops->owner_flag_bit,
                            &sp->so_flags))
                continue;
            atomic_inc(&sp->so_count);
            spin_unlock(&clp->cl_lock);
            rcu_read_unlock();

            status = nfs4_reclaim_open_state(sp, ops);
            if (status < 0) {
                set_bit(ops->owner_flag_bit, &sp->so_flags);
                nfs4_put_state_owner(sp);
                return nfs4_recovery_handle_error(clp, status);
            }

            nfs4_put_state_owner(sp);
            goto restart;
        }
        spin_unlock(&clp->cl_lock);
    }
    rcu_read_unlock();
    return status;
}

static int nfs4_check_lease(struct nfs_client *clp)
{
    struct rpc_cred *cred;
    const struct nfs4_state_maintenance_ops *ops =
        clp->cl_mvops->state_renewal_ops;
    int status;

    /* Is the client already known to have an expired lease? */
    if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
        return 0;
    spin_lock(&clp->cl_lock);
    cred = ops->get_state_renewal_cred_locked(clp);
    spin_unlock(&clp->cl_lock);
    if (cred == NULL) {
        cred = nfs4_get_setclientid_cred(clp);
        status = -ENOKEY;
        if (cred == NULL)
            goto out;
    }
    status = ops->renew_lease(clp, cred);
    put_rpccred(cred);
out:
    return nfs4_recovery_handle_error(clp, status);
}

/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
 * and for recoverable errors on EXCHANGE_ID for v4.1
 */
static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
{
    switch (status) {
    case -NFS4ERR_SEQ_MISORDERED:
        if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
            return -ESERVERFAULT;
        /* Lease confirmation error: retry after purging the lease */
        ssleep(1);
        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
        break;
    case -NFS4ERR_STALE_CLIENTID:
        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
        nfs4_state_clear_reclaim_reboot(clp);
        nfs4_state_start_reclaim_reboot(clp);
        break;
    case -NFS4ERR_CLID_INUSE:
        pr_err("NFS: Server %s reports our clientid is in use\n",
            clp->cl_hostname);
        nfs_mark_client_ready(clp, -EPERM);
        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
        return -EPERM;
    case -EACCES:
        if (clp->cl_machine_cred == NULL)
            return -EACCES;
        /* Handle case where the user hasn't set up machine creds */
        nfs4_clear_machine_cred(clp);
    case -NFS4ERR_DELAY:
    case -ETIMEDOUT:
    case -EAGAIN:
        ssleep(1);
        break;

    case -NFS4ERR_MINOR_VERS_MISMATCH:
        if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
            nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
        dprintk("%s: exit with error %d for server %s\n",
                __func__, -EPROTONOSUPPORT, clp->cl_hostname);
        return -EPROTONOSUPPORT;
    case -EKEYEXPIRED:
        nfs4_warn_keyexpired(clp->cl_hostname);
    case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
                 * in nfs4_exchange_id */
    default:
        dprintk("%s: exit with error %d for server %s\n", __func__,
                status, clp->cl_hostname);
        return status;
    }
    set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
    dprintk("%s: handled error %d for server %s\n", __func__, status,
            clp->cl_hostname);
    return 0;
}

static int nfs4_establish_lease(struct nfs_client *clp)
{
    struct rpc_cred *cred;
    const struct nfs4_state_recovery_ops *ops =
        clp->cl_mvops->reboot_recovery_ops;
    int status;

    cred = ops->get_clid_cred(clp);
    if (cred == NULL)
        return -ENOENT;
    status = ops->establish_clid(clp, cred);
    put_rpccred(cred);
    if (status != 0)
        return status;
    pnfs_destroy_all_layouts(clp);
    return 0;
}

/*
 * Returns zero or a negative errno.  NFS4ERR values are converted
 * to local errno values.
 */
static int nfs4_reclaim_lease(struct nfs_client *clp)
{
    int status;

    status = nfs4_establish_lease(clp);
    if (status < 0)
        return nfs4_handle_reclaim_lease_error(clp, status);
    if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
        nfs4_state_start_reclaim_nograce(clp);
    if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
        set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
    clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
    clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
    return 0;
}

static int nfs4_purge_lease(struct nfs_client *clp)
{
    int status;

    status = nfs4_establish_lease(clp);
    if (status < 0)
        return nfs4_handle_reclaim_lease_error(clp, status);
    clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
    set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
    nfs4_state_start_reclaim_nograce(clp);
    return 0;
}

int nfs4_discover_server_trunking(struct nfs_client *clp,
                  struct nfs_client **result)
{
    const struct nfs4_state_recovery_ops *ops =
                clp->cl_mvops->reboot_recovery_ops;
    rpc_authflavor_t *flavors, flav, save;
    struct rpc_clnt *clnt;
    struct rpc_cred *cred;
    int i, len, status;

    dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);

    len = NFS_MAX_SECFLAVORS;
    flavors = kcalloc(len, sizeof(*flavors), GFP_KERNEL);
    if (flavors == NULL) {
        status = -ENOMEM;
        goto out;
    }
    len = rpcauth_list_flavors(flavors, len);
    if (len < 0) {
        status = len;
        goto out_free;
    }
    clnt = clp->cl_rpcclient;
    save = clnt->cl_auth->au_flavor;
    i = 0;

    mutex_lock(&nfs_clid_init_mutex);
    status  = -ENOENT;
again:
    cred = ops->get_clid_cred(clp);
    if (cred == NULL)
        goto out_unlock;

    status = ops->detect_trunking(clp, result, cred);
    put_rpccred(cred);
    switch (status) {
    case 0:
        break;

    case -EACCES:
        if (clp->cl_machine_cred == NULL)
            break;
        /* Handle case where the user hasn't set up machine creds */
        nfs4_clear_machine_cred(clp);
    case -NFS4ERR_DELAY:
    case -ETIMEDOUT:
    case -EAGAIN:
        ssleep(1);
        dprintk("NFS: %s after status %d, retrying\n",
            __func__, status);
        goto again;

    case -NFS4ERR_CLID_INUSE:
    case -NFS4ERR_WRONGSEC:
        status = -EPERM;
        if (i >= len)
            break;

        flav = flavors[i++];
        if (flav == save)
            flav = flavors[i++];
        clnt = rpc_clone_client_set_auth(clnt, flav);
        if (IS_ERR(clnt)) {
            status = PTR_ERR(clnt);
            break;
        }
        clp->cl_rpcclient = clnt;
        goto again;

    case -NFS4ERR_MINOR_VERS_MISMATCH:
        status = -EPROTONOSUPPORT;
        break;

    case -EKEYEXPIRED:
        nfs4_warn_keyexpired(clp->cl_hostname);
    case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
                 * in nfs4_exchange_id */
        status = -EKEYEXPIRED;
    }

out_unlock:
    mutex_unlock(&nfs_clid_init_mutex);
out_free:
    kfree(flavors);
out:
    dprintk("NFS: %s: status = %d\n", __func__, status);
    return status;
}

#ifdef CONFIG_NFS_V4_1
void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
{
    struct nfs_client *clp = session->clp;

    switch (err) {
    default:
        set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
        break;
    case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
        set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
    }
    nfs4_schedule_lease_recovery(clp);
}
EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);

void nfs41_handle_recall_slot(struct nfs_client *clp)
{
    set_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
    dprintk("%s: scheduling slot recall for server %s\n", __func__,
            clp->cl_hostname);
    nfs4_schedule_state_manager(clp);
}

static void nfs4_reset_all_state(struct nfs_client *clp)
{
    if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
        set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
        nfs4_state_start_reclaim_nograce(clp);
        dprintk("%s: scheduling reset of all state for server %s!\n",
                __func__, clp->cl_hostname);
        nfs4_schedule_state_manager(clp);
    }
}

static void nfs41_handle_server_reboot(struct nfs_client *clp)
{
    if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
        nfs4_state_start_reclaim_reboot(clp);
        dprintk("%s: server %s rebooted!\n", __func__,
                clp->cl_hostname);
        nfs4_schedule_state_manager(clp);
    }
}

static void nfs41_handle_state_revoked(struct nfs_client *clp)
{
    nfs4_reset_all_state(clp);
    dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
}

static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
{
    /* This will need to handle layouts too */
    nfs_expire_all_delegations(clp);
    dprintk("%s: Recallable state revoked on server %s!\n", __func__,
            clp->cl_hostname);
}

static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
{
    nfs_expire_all_delegations(clp);
    if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
        nfs4_schedule_state_manager(clp);
    dprintk("%s: server %s declared a backchannel fault\n", __func__,
            clp->cl_hostname);
}

static void nfs41_handle_cb_path_down(struct nfs_client *clp)
{
    if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
        &clp->cl_state) == 0)
        nfs4_schedule_state_manager(clp);
}

void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
{
    if (!flags)
        return;

    dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
        __func__, clp->cl_hostname, clp->cl_clientid, flags);

    if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
        nfs41_handle_server_reboot(clp);
    if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
                SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
                SEQ4_STATUS_ADMIN_STATE_REVOKED |
                SEQ4_STATUS_LEASE_MOVED))
        nfs41_handle_state_revoked(clp);
    if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
        nfs41_handle_recallable_state_revoked(clp);
    if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
        nfs41_handle_backchannel_fault(clp);
    else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
                SEQ4_STATUS_CB_PATH_DOWN_SESSION))
        nfs41_handle_cb_path_down(clp);
}

static int nfs4_reset_session(struct nfs_client *clp)
{
    struct rpc_cred *cred;
    int status;

    if (!nfs4_has_session(clp))
        return 0;
    nfs4_begin_drain_session(clp);
    cred = nfs4_get_exchange_id_cred(clp);
    status = nfs4_proc_destroy_session(clp->cl_session, cred);
    if (status && status != -NFS4ERR_BADSESSION &&
        status != -NFS4ERR_DEADSESSION) {
        status = nfs4_recovery_handle_error(clp, status);
        goto out;
    }

    memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
    status = nfs4_proc_create_session(clp, cred);
    if (status) {
        dprintk("%s: session reset failed with status %d for server %s!\n",
            __func__, status, clp->cl_hostname);
        status = nfs4_handle_reclaim_lease_error(clp, status);
        goto out;
    }
    nfs41_finish_session_reset(clp);
    dprintk("%s: session reset was successful for server %s!\n",
            __func__, clp->cl_hostname);
out:
    if (cred)
        put_rpccred(cred);
    return status;
}

static int nfs4_recall_slot(struct nfs_client *clp)
{
    struct nfs4_slot_table *fc_tbl;
    struct nfs4_slot *new, *old;
    int i;

    if (!nfs4_has_session(clp))
        return 0;
    nfs4_begin_drain_session(clp);
    fc_tbl = &clp->cl_session->fc_slot_table;
    new = kmalloc(fc_tbl->target_max_slots * sizeof(struct nfs4_slot),
              GFP_NOFS);
        if (!new)
        return -ENOMEM;

    spin_lock(&fc_tbl->slot_tbl_lock);
    for (i = 0; i < fc_tbl->target_max_slots; i++)
        new[i].seq_nr = fc_tbl->slots[i].seq_nr;
    old = fc_tbl->slots;
    fc_tbl->slots = new;
    fc_tbl->max_slots = fc_tbl->target_max_slots;
    fc_tbl->target_max_slots = 0;
    clp->cl_session->fc_attrs.max_reqs = fc_tbl->max_slots;
    spin_unlock(&fc_tbl->slot_tbl_lock);

    kfree(old);
    return 0;
}

static int nfs4_bind_conn_to_session(struct nfs_client *clp)
{
    struct rpc_cred *cred;
    int ret;

    if (!nfs4_has_session(clp))
        return 0;
    nfs4_begin_drain_session(clp);
    cred = nfs4_get_exchange_id_cred(clp);
    ret = nfs4_proc_bind_conn_to_session(clp, cred);
    if (cred)
        put_rpccred(cred);
    clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
    switch (ret) {
    case 0:
        dprintk("%s: bind_conn_to_session was successful for server %s!\n",
            __func__, clp->cl_hostname);
        break;
    case -NFS4ERR_DELAY:
        ssleep(1);
        set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
        break;
    default:
        return nfs4_recovery_handle_error(clp, ret);
    }
    return 0;
}
#else /* CONFIG_NFS_V4_1 */
static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
static int nfs4_recall_slot(struct nfs_client *clp) { return 0; }

static int nfs4_bind_conn_to_session(struct nfs_client *clp)
{
    return 0;
}
#endif /* CONFIG_NFS_V4_1 */

static void nfs4_state_manager(struct nfs_client *clp)
{
    int status = 0;
    const char *section = "", *section_sep = "";

    /* Ensure exclusive access to NFSv4 state */
    do {
        if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
            section = "purge state";
            status = nfs4_purge_lease(clp);
            if (status < 0)
                goto out_error;
            continue;
        }

        if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
            section = "lease expired";
            /* We're going to have to re-establish a clientid */
            status = nfs4_reclaim_lease(clp);
            if (status < 0)
                goto out_error;
            continue;
        }

        if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
            section = "check lease";
            status = nfs4_check_lease(clp);
            if (status < 0)
                goto out_error;
            if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
                continue;
        }

        /* Initialize or reset the session */
        if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
            section = "reset session";
            status = nfs4_reset_session(clp);
            if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
                continue;
            if (status < 0)
                goto out_error;
        }

        /* Send BIND_CONN_TO_SESSION */
        if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
                &clp->cl_state)) {
            section = "bind conn to session";
            status = nfs4_bind_conn_to_session(clp);
            if (status < 0)
                goto out_error;
            continue;
        }

        /* Recall session slots */
        if (test_and_clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state)) {
            section = "recall slot";
            status = nfs4_recall_slot(clp);
            if (status < 0)
                goto out_error;
            continue;
        }

        /* First recover reboot state... */
        if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
            section = "reclaim reboot";
            status = nfs4_do_reclaim(clp,
                clp->cl_mvops->reboot_recovery_ops);
            if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
                test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
                continue;
            nfs4_state_end_reclaim_reboot(clp);
            if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
                continue;
            if (status < 0)
                goto out_error;
        }

        /* Now recover expired state... */
        if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
            section = "reclaim nograce";
            status = nfs4_do_reclaim(clp,
                clp->cl_mvops->nograce_recovery_ops);
            if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
                test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) ||
                test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
                continue;
            if (status < 0)
                goto out_error;
        }

        nfs4_end_drain_session(clp);
        if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
            nfs_client_return_marked_delegations(clp);
            continue;
        }

        nfs4_clear_state_manager_bit(clp);
        /* Did we race with an attempt to give us more work? */
        if (clp->cl_state == 0)
            break;
        if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
            break;
    } while (atomic_read(&clp->cl_count) > 1);
    return;
out_error:
    if (strlen(section))
        section_sep = ": ";
    pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
            " with error %d\n", section_sep, section,
            clp->cl_hostname, -status);
    ssleep(1);
    nfs4_end_drain_session(clp);
    nfs4_clear_state_manager_bit(clp);
}

static int nfs4_run_state_manager(void *ptr)
{
    struct nfs_client *clp = ptr;

    allow_signal(SIGKILL);
    nfs4_state_manager(clp);
    nfs_put_client(clp);
    module_put_and_exit(0);
    return 0;
}

/*
 * Local variables:
 *  c-basic-offset: 8
 * End:
 */