/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/nfs4.h>
#include <linux/nfs.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs_fs.h>
#include "internal.h"
#include "nfs4_fs.h"
#include "nfs40.h"
#include "nfs4session.h"
#include "nfs4trace.h"

static void nfs40_call_sync_prepare(struct rpc_task *task, void *calldata)
{
        struct nfs4_call_sync_data *data = calldata;
        nfs4_setup_sequence(data->seq_server->nfs_client,
                                data->seq_args, data->seq_res, task);
}

static void nfs40_call_sync_done(struct rpc_task *task, void *calldata)
{
        struct nfs4_call_sync_data *data = calldata;
        nfs4_sequence_done(task, data->seq_res);
}

static void nfs40_sequence_free_slot(struct nfs4_sequence_res *res)
{
        struct nfs4_slot *slot = res->sr_slot;
        struct nfs4_slot_table *tbl;

        tbl = slot->table;
        spin_lock(&tbl->slot_tbl_lock);
        if (!nfs41_wake_and_assign_slot(tbl, slot))
                nfs4_free_slot(tbl, slot);
        spin_unlock(&tbl->slot_tbl_lock);

        res->sr_slot = NULL;
}

static int nfs40_sequence_done(struct rpc_task *task,
                               struct nfs4_sequence_res *res)
{
        if (res->sr_slot != NULL)
                nfs40_sequence_free_slot(res);
        return 1;
}

static void nfs40_clear_delegation_stateid(struct nfs4_state *state)
{
        if (rcu_access_pointer(NFS_I(state->inode)->delegation) != NULL)
                nfs_finish_clear_delegation_stateid(state, NULL);
}

static int nfs40_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
        /* NFSv4.0 doesn't allow for delegation recovery on open expire */
        nfs40_clear_delegation_stateid(state);
        nfs_state_clear_open_state_flags(state);
        return nfs4_open_expired(sp, state);
}

struct nfs4_renewdata {
        struct nfs_client       *client;
        unsigned long           timestamp;
};

/*
 * nfs4_proc_async_renew(): This is not one of the nfs_rpc_ops; it is a special
 * standalone procedure for queueing an asynchronous RENEW.
 */
static void nfs4_renew_release(void *calldata)
{
        struct nfs4_renewdata *data = calldata;
        struct nfs_client *clp = data->client;

        if (refcount_read(&clp->cl_count) > 1)
                nfs4_schedule_state_renewal(clp);
        nfs_put_client(clp);
        kfree(data);
}

static void nfs4_renew_done(struct rpc_task *task, void *calldata)
{
        struct nfs4_renewdata *data = calldata;
        struct nfs_client *clp = data->client;
        unsigned long timestamp = data->timestamp;

        trace_nfs4_renew_async(clp, task->tk_status);
        switch (task->tk_status) {
        case 0:
                break;
        case -NFS4ERR_LEASE_MOVED:
                nfs4_schedule_lease_moved_recovery(clp);
                break;
        default:
                /* Unless we're shutting down, schedule state recovery! */
                if (test_bit(NFS_CS_RENEWD, &clp->cl_res_state) == 0)
                        return;
                if (task->tk_status != NFS4ERR_CB_PATH_DOWN) {
                        nfs4_schedule_lease_recovery(clp);
                        return;
                }
                nfs4_schedule_path_down_recovery(clp);
        }
        do_renew_lease(clp, timestamp);
}

static const struct rpc_call_ops nfs4_renew_ops = {
        .rpc_call_done = nfs4_renew_done,
        .rpc_release = nfs4_renew_release,
};

static int nfs4_proc_async_renew(struct nfs_client *clp, const struct cred *cred, unsigned renew_flags)
{
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_RENEW],
                .rpc_argp       = clp,
                .rpc_cred       = cred,
        };
        struct nfs4_renewdata *data;

        if (renew_flags == 0)
                return 0;
        if (!refcount_inc_not_zero(&clp->cl_count))
                return -EIO;
        data = kmalloc_obj(*data, GFP_NOFS);
        if (data == NULL) {
                nfs_put_client(clp);
                return -ENOMEM;
        }
        data->client = clp;
        data->timestamp = jiffies;
        return rpc_call_async(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT,
                        &nfs4_renew_ops, data);
}

static int nfs4_proc_renew(struct nfs_client *clp, const struct cred *cred)
{
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_RENEW],
                .rpc_argp       = clp,
                .rpc_cred       = cred,
        };
        unsigned long now = jiffies;
        int status;

        status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
        if (status < 0)
                return status;
        do_renew_lease(clp, now);
        return 0;
}

static int nfs40_test_and_free_expired_stateid(struct nfs_server *server,
                                               nfs4_stateid *stateid,
                                               const struct cred *cred)
{
        return -NFS4ERR_BAD_STATEID;
}

/*
 * This operation also signals the server that this client is
 * performing migration recovery.  The server can stop returning
 * NFS4ERR_LEASE_MOVED to this client.  A RENEW operation is
 * appended to this compound to identify the client ID which is
 * performing recovery.
 */
static int _nfs40_proc_get_locations(struct nfs_server *server,
                                     struct nfs_fh *fhandle,
                                     struct nfs4_fs_locations *locations,
                                     struct page *page, const struct cred *cred)
{
        struct rpc_clnt *clnt = server->client;
        struct nfs_client *clp = server->nfs_client;
        u32 bitmask[2] = {
                [0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
        };
        struct nfs4_fs_locations_arg args = {
                .clientid       = clp->cl_clientid,
                .fh             = fhandle,
                .page           = page,
                .bitmask        = bitmask,
                .migration      = 1,            /* skip LOOKUP */
                .renew          = 1,            /* append RENEW */
        };
        struct nfs4_fs_locations_res res = {
                .fs_locations   = locations,
                .migration      = 1,
                .renew          = 1,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
                .rpc_argp       = &args,
                .rpc_resp       = &res,
                .rpc_cred       = cred,
        };
        unsigned long now = jiffies;
        int status;

        nfs_fattr_init(locations->fattr);
        locations->server = server;
        locations->nlocations = 0;

        nfs4_init_sequence(clp, &args.seq_args, &res.seq_res, 0, 1);
        status = nfs4_call_sync_sequence(clnt, server, &msg,
                                        &args.seq_args, &res.seq_res);
        if (status)
                return status;

        renew_lease(server, now);
        return 0;
}

/*
 * This operation also signals the server that this client is
 * performing "lease moved" recovery.  The server can stop
 * returning NFS4ERR_LEASE_MOVED to this client.  A RENEW operation
 * is appended to this compound to identify the client ID which is
 * performing recovery.
 */
static int _nfs40_proc_fsid_present(struct inode *inode, const struct cred *cred)
{
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
        struct rpc_clnt *clnt = server->client;
        struct nfs4_fsid_present_arg args = {
                .fh             = NFS_FH(inode),
                .clientid       = clp->cl_clientid,
                .renew          = 1,            /* append RENEW */
        };
        struct nfs4_fsid_present_res res = {
                .renew          = 1,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_FSID_PRESENT],
                .rpc_argp       = &args,
                .rpc_resp       = &res,
                .rpc_cred       = cred,
        };
        unsigned long now = jiffies;
        int status;

        res.fh = nfs_alloc_fhandle();
        if (res.fh == NULL)
                return -ENOMEM;

        nfs4_init_sequence(clp, &args.seq_args, &res.seq_res, 0, 1);
        status = nfs4_call_sync_sequence(clnt, server, &msg,
                                                &args.seq_args, &res.seq_res);
        nfs_free_fhandle(res.fh);
        if (status)
                return status;

        do_renew_lease(clp, now);
        return 0;
}

struct nfs_release_lockowner_data {
        struct nfs4_lock_state *lsp;
        struct nfs_server *server;
        struct nfs_release_lockowner_args args;
        struct nfs_release_lockowner_res res;
        unsigned long timestamp;
};

static void nfs4_release_lockowner_prepare(struct rpc_task *task, void *calldata)
{
        struct nfs_release_lockowner_data *data = calldata;
        struct nfs_server *server = data->server;
        nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
                           &data->res.seq_res, task);
        data->args.lock_owner.clientid = server->nfs_client->cl_clientid;
        data->timestamp = jiffies;
}

static void nfs4_release_lockowner_done(struct rpc_task *task, void *calldata)
{
        struct nfs_release_lockowner_data *data = calldata;
        struct nfs_server *server = data->server;

        nfs40_sequence_done(task, &data->res.seq_res);

        switch (task->tk_status) {
        case 0:
                renew_lease(server, data->timestamp);
                break;
        case -NFS4ERR_STALE_CLIENTID:
        case -NFS4ERR_EXPIRED:
                nfs4_schedule_lease_recovery(server->nfs_client);
                break;
        case -NFS4ERR_LEASE_MOVED:
        case -NFS4ERR_DELAY:
                if (nfs4_async_handle_error(task, server,
                                            NULL, NULL) == -EAGAIN)
                        rpc_restart_call_prepare(task);
        }
}

static void nfs4_release_lockowner_release(void *calldata)
{
        struct nfs_release_lockowner_data *data = calldata;
        nfs4_free_lock_state(data->server, data->lsp);
        kfree(calldata);
}

static const struct rpc_call_ops nfs4_release_lockowner_ops = {
        .rpc_call_prepare = nfs4_release_lockowner_prepare,
        .rpc_call_done = nfs4_release_lockowner_done,
        .rpc_release = nfs4_release_lockowner_release,
};

static void
nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_state *lsp)
{
        struct nfs_release_lockowner_data *data;
        struct nfs_client *clp = server->nfs_client;
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RELEASE_LOCKOWNER],
        };

        if (clp->cl_mvops->minor_version != 0)
                return;

        data = kmalloc_obj(*data);
        if (!data)
                return;
        data->lsp = lsp;
        data->server = server;
        data->args.lock_owner.clientid = clp->cl_clientid;
        data->args.lock_owner.id = lsp->ls_seqid.owner_id;
        data->args.lock_owner.s_dev = server->s_dev;

        msg.rpc_argp = &data->args;
        msg.rpc_resp = &data->res;
        nfs4_init_sequence(clp, &data->args.seq_args, &data->res.seq_res, 0, 0);
        rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, data);
}

static const struct rpc_call_ops nfs40_call_sync_ops = {
        .rpc_call_prepare = nfs40_call_sync_prepare,
        .rpc_call_done = nfs40_call_sync_done,
};

static const struct nfs4_sequence_slot_ops nfs40_sequence_slot_ops = {
        .process = nfs40_sequence_done,
        .done = nfs40_sequence_done,
        .free_slot = nfs40_sequence_free_slot,
};

static const struct nfs4_state_recovery_ops nfs40_reboot_recovery_ops = {
        .owner_flag_bit = NFS_OWNER_RECLAIM_REBOOT,
        .state_flag_bit = NFS_STATE_RECLAIM_REBOOT,
        .recover_open   = nfs4_open_reclaim,
        .recover_lock   = nfs4_lock_reclaim,
        .establish_clid = nfs4_init_clientid,
        .detect_trunking = nfs40_discover_server_trunking,
};

static const struct nfs4_state_recovery_ops nfs40_nograce_recovery_ops = {
        .owner_flag_bit = NFS_OWNER_RECLAIM_NOGRACE,
        .state_flag_bit = NFS_STATE_RECLAIM_NOGRACE,
        .recover_open   = nfs40_open_expired,
        .recover_lock   = nfs4_lock_expired,
        .establish_clid = nfs4_init_clientid,
};

static const struct nfs4_state_maintenance_ops nfs40_state_renewal_ops = {
        .sched_state_renewal = nfs4_proc_async_renew,
        .get_state_renewal_cred = nfs4_get_renew_cred,
        .renew_lease = nfs4_proc_renew,
};

static const struct nfs4_mig_recovery_ops nfs40_mig_recovery_ops = {
        .get_locations = _nfs40_proc_get_locations,
        .fsid_present = _nfs40_proc_fsid_present,
};

const struct nfs4_minor_version_ops nfs_v4_0_minor_ops = {
        .minor_version = 0,
        .init_caps = NFS_CAP_READDIRPLUS
                | NFS_CAP_ATOMIC_OPEN
                | NFS_CAP_POSIX_LOCK,
        .init_client = nfs40_init_client,
        .shutdown_client = nfs40_shutdown_client,
        .match_stateid = nfs4_match_stateid,
        .find_root_sec = nfs4_find_root_sec,
        .free_lock_state = nfs4_release_lockowner,
        .test_and_free_expired = nfs40_test_and_free_expired_stateid,
        .alloc_seqid = nfs_alloc_seqid,
        .call_sync_ops = &nfs40_call_sync_ops,
        .sequence_slot_ops = &nfs40_sequence_slot_ops,
        .reboot_recovery_ops = &nfs40_reboot_recovery_ops,
        .nograce_recovery_ops = &nfs40_nograce_recovery_ops,
        .state_renewal_ops = &nfs40_state_renewal_ops,
        .mig_recovery_ops = &nfs40_mig_recovery_ops,
};