// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
 */
#include <linux/fs.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs4.h>
#include <linux/nfs_xdr.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "nfs42.h"
#include "iostat.h"
#include "pnfs.h"
#include "nfs4session.h"
#include "internal.h"
#include "delegation.h"
#include "nfs4trace.h"

#define NFSDBG_FACILITY NFSDBG_PROC
static int nfs42_do_offload_cancel_async(struct file *dst, nfs4_stateid *std);
static int nfs42_proc_offload_status(struct file *file, nfs4_stateid *stateid,
                                     u64 *copied);

static void nfs42_set_netaddr(struct file *filep, struct nfs42_netaddr *naddr)
{
        struct nfs_client *clp = (NFS_SERVER(file_inode(filep)))->nfs_client;
        unsigned short port = 2049;

        rcu_read_lock();
        naddr->netid_len = scnprintf(naddr->netid,
                                        sizeof(naddr->netid), "%s",
                                        rpc_peeraddr2str(clp->cl_rpcclient,
                                        RPC_DISPLAY_NETID));
        naddr->addr_len = scnprintf(naddr->addr,
                                        sizeof(naddr->addr),
                                        "%s.%u.%u",
                                        rpc_peeraddr2str(clp->cl_rpcclient,
                                        RPC_DISPLAY_ADDR),
                                        port >> 8, port & 255);
        rcu_read_unlock();
}

static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
                struct nfs_lock_context *lock, loff_t offset, loff_t len)
{
        struct inode *inode = file_inode(filep);
        struct nfs_server *server = NFS_SERVER(inode);
        u32 bitmask[NFS_BITMASK_SZ];
        struct nfs42_falloc_args args = {
                .falloc_fh      = NFS_FH(inode),
                .falloc_offset  = offset,
                .falloc_length  = len,
                .falloc_bitmask = bitmask,
        };
        struct nfs42_falloc_res res = {
                .falloc_server  = server,
        };
        int status;

        msg->rpc_argp = &args;
        msg->rpc_resp = &res;

        status = nfs4_set_rw_stateid(&args.falloc_stateid, lock->open_context,
                        lock, FMODE_WRITE);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                return status;
        }

        nfs4_bitmask_set(bitmask, server->cache_consistency_bitmask, inode,
                         NFS_INO_INVALID_BLOCKS);

        res.falloc_fattr = nfs_alloc_fattr();
        if (!res.falloc_fattr)
                return -ENOMEM;

        status = nfs4_call_sync(server->client, server, msg,
                                &args.seq_args, &res.seq_res, 0);
        if (status == 0) {
                if (nfs_should_remove_suid(inode)) {
                        spin_lock(&inode->i_lock);
                        nfs_set_cache_invalid(inode,
                                NFS_INO_REVAL_FORCED | NFS_INO_INVALID_MODE);
                        spin_unlock(&inode->i_lock);
                }
                status = nfs_post_op_update_inode_force_wcc(inode,
                                                            res.falloc_fattr);
        }
        if (msg->rpc_proc == &nfs4_procedures[NFSPROC4_CLNT_ALLOCATE])
                trace_nfs4_fallocate(inode, &args, status);
        else
                trace_nfs4_deallocate(inode, &args, status);
        kfree(res.falloc_fattr);
        return status;
}

static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
                                loff_t offset, loff_t len)
{
        struct inode *inode = file_inode(filep);
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs4_exception exception = { };
        struct nfs_lock_context *lock;
        int err;

        lock = nfs_get_lock_context(nfs_file_open_context(filep));
        if (IS_ERR(lock))
                return PTR_ERR(lock);

        exception.inode = inode;
        exception.state = lock->open_context->state;

        err = nfs_sync_inode(inode);
        if (err)
                goto out;

        do {
                err = _nfs42_proc_fallocate(msg, filep, lock, offset, len);
                if (err == -ENOTSUPP) {
                        err = -EOPNOTSUPP;
                        break;
                }
                err = nfs4_handle_exception(server, err, &exception);
        } while (exception.retry);
out:
        nfs_put_lock_context(lock);
        return err;
}

int nfs42_proc_allocate(struct file *filep, loff_t offset, loff_t len)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ALLOCATE],
        };
        struct inode *inode = file_inode(filep);
        loff_t oldsize;
        int err;

        if (!nfs_server_capable(inode, NFS_CAP_ALLOCATE))
                return -EOPNOTSUPP;

        err = nfs_start_io_write(inode);
        if (err)
                return err;

        oldsize = i_size_read(inode);

        err = nfs42_proc_fallocate(&msg, filep, offset, len);

        if (err == 0)
                nfs_truncate_last_folio(inode->i_mapping, oldsize,
                                        offset + len);
        else if (err == -EOPNOTSUPP)
                NFS_SERVER(inode)->caps &= ~(NFS_CAP_ALLOCATE |
                                             NFS_CAP_ZERO_RANGE);

        nfs_end_io_write(inode);
        return err;
}

int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DEALLOCATE],
        };
        struct inode *inode = file_inode(filep);
        int err;

        if (!nfs_server_capable(inode, NFS_CAP_DEALLOCATE))
                return -EOPNOTSUPP;

        err = nfs_start_io_write(inode);
        if (err)
                return err;

        err = nfs42_proc_fallocate(&msg, filep, offset, len);
        if (err == 0)
                truncate_pagecache_range(inode, offset, (offset + len) -1);
        if (err == -EOPNOTSUPP)
                NFS_SERVER(inode)->caps &= ~(NFS_CAP_DEALLOCATE |
                                             NFS_CAP_ZERO_RANGE);

        nfs_end_io_write(inode);
        return err;
}

int nfs42_proc_zero_range(struct file *filep, loff_t offset, loff_t len)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ZERO_RANGE],
        };
        struct inode *inode = file_inode(filep);
        loff_t oldsize;
        int err;

        if (!nfs_server_capable(inode, NFS_CAP_ZERO_RANGE))
                return -EOPNOTSUPP;

        err = nfs_start_io_write(inode);
        if (err)
                return err;

        oldsize = i_size_read(inode);
        err = nfs42_proc_fallocate(&msg, filep, offset, len);
        if (err == 0) {
                nfs_truncate_last_folio(inode->i_mapping, oldsize,
                                        offset + len);
                truncate_pagecache_range(inode, offset, (offset + len) -1);
        } else if (err == -EOPNOTSUPP)
                NFS_SERVER(inode)->caps &= ~NFS_CAP_ZERO_RANGE;

        nfs_end_io_write(inode);
        return err;
}

static void nfs4_copy_dequeue_callback(struct nfs_server *dst_server,
                                       struct nfs_server *src_server,
                                       struct nfs4_copy_state *copy)
{
        spin_lock(&dst_server->nfs_client->cl_lock);
        list_del_init(&copy->copies);
        spin_unlock(&dst_server->nfs_client->cl_lock);
        if (dst_server != src_server) {
                spin_lock(&src_server->nfs_client->cl_lock);
                list_del_init(&copy->src_copies);
                spin_unlock(&src_server->nfs_client->cl_lock);
        }
}

static int handle_async_copy(struct nfs42_copy_res *res,
                             struct nfs_server *dst_server,
                             struct nfs_server *src_server,
                             struct file *src,
                             struct file *dst,
                             nfs4_stateid *src_stateid,
                             bool *restart)
{
        struct nfs4_copy_state *copy, *tmp_copy = NULL, *iter;
        struct nfs_open_context *dst_ctx = nfs_file_open_context(dst);
        struct nfs_open_context *src_ctx = nfs_file_open_context(src);
        struct nfs_client *clp = dst_server->nfs_client;
        unsigned long timeout = 3 * HZ;
        int status = NFS4_OK;
        u64 copied;

        copy = kzalloc_obj(struct nfs4_copy_state);
        if (!copy)
                return -ENOMEM;

        spin_lock(&dst_server->nfs_client->cl_lock);
        list_for_each_entry(iter,
                                &dst_server->nfs_client->pending_cb_stateids,
                                copies) {
                if (memcmp(&res->write_res.stateid, &iter->stateid,
                                NFS4_STATEID_SIZE))
                        continue;
                tmp_copy = iter;
                list_del(&iter->copies);
                break;
        }
        if (tmp_copy) {
                spin_unlock(&dst_server->nfs_client->cl_lock);
                kfree(copy);
                copy = tmp_copy;
                goto out;
        }

        memcpy(&copy->stateid, &res->write_res.stateid, NFS4_STATEID_SIZE);
        init_completion(&copy->completion);
        copy->parent_dst_state = dst_ctx->state;
        copy->parent_src_state = src_ctx->state;

        list_add_tail(&copy->copies, &dst_server->ss_copies);
        spin_unlock(&dst_server->nfs_client->cl_lock);

        if (dst_server != src_server) {
                spin_lock(&src_server->nfs_client->cl_lock);
                list_add_tail(&copy->src_copies, &src_server->ss_src_copies);
                spin_unlock(&src_server->nfs_client->cl_lock);
        }

wait:
        status = wait_for_completion_interruptible_timeout(&copy->completion,
                                                           timeout);
        if (!status)
                goto timeout;
        nfs4_copy_dequeue_callback(dst_server, src_server, copy);
        if (status == -ERESTARTSYS) {
                goto out_cancel;
        } else if (copy->flags || copy->error == NFS4ERR_PARTNER_NO_AUTH) {
                status = -EAGAIN;
                *restart = true;
                goto out_cancel;
        }
out:
        res->write_res.count = copy->count;
        /* Copy out the updated write verifier provided by CB_OFFLOAD. */
        memcpy(&res->write_res.verifier, &copy->verf, sizeof(copy->verf));
        status = -copy->error;

out_free:
        kfree(copy);
        return status;
out_cancel:
        nfs42_do_offload_cancel_async(dst, &copy->stateid);
        if (!nfs42_files_from_same_server(src, dst))
                nfs42_do_offload_cancel_async(src, src_stateid);
        goto out_free;
timeout:
        timeout <<= 1;
        if (timeout > (clp->cl_lease_time >> 1))
                timeout = clp->cl_lease_time >> 1;
        status = nfs42_proc_offload_status(dst, &copy->stateid, &copied);
        if (status == -EINPROGRESS)
                goto wait;
        nfs4_copy_dequeue_callback(dst_server, src_server, copy);
        switch (status) {
        case 0:
                /* The server recognized the copy stateid, so it hasn't
                 * rebooted. Don't overwrite the verifier returned in the
                 * COPY result. */
                res->write_res.count = copied;
                goto out_free;
        case -EREMOTEIO:
                /* COPY operation failed on the server. */
                status = -EOPNOTSUPP;
                res->write_res.count = copied;
                goto out_free;
        case -EBADF:
                /* Server did not recognize the copy stateid. It has
                 * probably restarted and lost the plot. */
                res->write_res.count = 0;
                status = -EOPNOTSUPP;
                break;
        case -EOPNOTSUPP:
                /* RFC 7862 REQUIREs server to support OFFLOAD_STATUS when
                 * it has signed up for an async COPY, so server is not
                 * spec-compliant. */
                res->write_res.count = 0;
        }
        goto out_free;
}

static int process_copy_commit(struct file *dst, loff_t pos_dst,
                               struct nfs42_copy_res *res)
{
        struct nfs_commitres cres;
        int status = -ENOMEM;

        cres.verf = kzalloc_obj(struct nfs_writeverf);
        if (!cres.verf)
                goto out;

        status = nfs4_proc_commit(dst, pos_dst, res->write_res.count, &cres);
        if (status)
                goto out_free;
        if (nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
                                    &cres.verf->verifier)) {
                dprintk("commit verf differs from copy verf\n");
                status = -EAGAIN;
        }
out_free:
        kfree(cres.verf);
out:
        return status;
}

/**
 * nfs42_copy_dest_done - perform inode cache updates after clone/copy offload
 * @file: pointer to destination file
 * @pos: destination offset
 * @len: copy length
 * @oldsize: length of the file prior to clone/copy
 *
 * Punch a hole in the inode page cache, so that the NFS client will
 * know to retrieve new data.
 * Update the file size if necessary, and then mark the inode as having
 * invalid cached values for change attribute, ctime, mtime and space used.
 */
static void nfs42_copy_dest_done(struct file *file, loff_t pos, loff_t len,
                                 loff_t oldsize)
{
        struct inode *inode = file_inode(file);
        struct address_space *mapping = file->f_mapping;
        loff_t newsize = pos + len;
        loff_t end = newsize - 1;

        nfs_truncate_last_folio(mapping, oldsize, pos);
        WARN_ON_ONCE(invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
                                                   end >> PAGE_SHIFT));

        spin_lock(&inode->i_lock);
        if (newsize > i_size_read(inode))
                i_size_write(inode, newsize);
        nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE |
                                             NFS_INO_INVALID_CTIME |
                                             NFS_INO_INVALID_MTIME |
                                             NFS_INO_INVALID_BLOCKS);
        spin_unlock(&inode->i_lock);
}

static ssize_t _nfs42_proc_copy(struct file *src,
                                struct nfs_lock_context *src_lock,
                                struct file *dst,
                                struct nfs_lock_context *dst_lock,
                                struct nfs42_copy_args *args,
                                struct nfs42_copy_res *res,
                                struct nl4_server *nss,
                                nfs4_stateid *cnr_stateid,
                                bool *restart)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COPY],
                .rpc_argp = args,
                .rpc_resp = res,
        };
        struct inode *dst_inode = file_inode(dst);
        struct inode *src_inode = file_inode(src);
        struct nfs_server *dst_server = NFS_SERVER(dst_inode);
        struct nfs_server *src_server = NFS_SERVER(src_inode);
        loff_t pos_src = args->src_pos;
        loff_t pos_dst = args->dst_pos;
        loff_t oldsize_dst;
        size_t count = args->count;
        ssize_t status;

        if (nss) {
                args->cp_src = nss;
                nfs4_stateid_copy(&args->src_stateid, cnr_stateid);
        } else {
                status = nfs4_set_rw_stateid(&args->src_stateid,
                                src_lock->open_context, src_lock, FMODE_READ);
                if (status) {
                        if (status == -EAGAIN)
                                status = -NFS4ERR_BAD_STATEID;
                        return status;
                }
        }
        status = nfs_filemap_write_and_wait_range(src->f_mapping,
                        pos_src, pos_src + (loff_t)count - 1);
        if (status)
                return status;

        status = nfs4_set_rw_stateid(&args->dst_stateid, dst_lock->open_context,
                                     dst_lock, FMODE_WRITE);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                return status;
        }

        nfs_file_block_o_direct(NFS_I(dst_inode));
        status = nfs_sync_inode(dst_inode);
        if (status)
                return status;

        res->commit_res.verf = NULL;
        if (args->sync) {
                res->commit_res.verf =
                        kzalloc_obj(struct nfs_writeverf);
                if (!res->commit_res.verf)
                        return -ENOMEM;
        }
        set_bit(NFS_CLNT_SRC_SSC_COPY_STATE,
                &src_lock->open_context->state->flags);
        set_bit(NFS_CLNT_DST_SSC_COPY_STATE,
                &dst_lock->open_context->state->flags);
        oldsize_dst = i_size_read(dst_inode);

        status = nfs4_call_sync(dst_server->client, dst_server, &msg,
                                &args->seq_args, &res->seq_res, 0);
        trace_nfs4_copy(src_inode, dst_inode, args, res, nss, status);
        if (status == -ENOTSUPP)
                dst_server->caps &= ~NFS_CAP_COPY;
        if (status)
                goto out;

        if (args->sync &&
                nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
                                    &res->commit_res.verf->verifier)) {
                status = -EAGAIN;
                goto out;
        }

        if (!res->synchronous) {
                status = handle_async_copy(res, dst_server, src_server, src,
                                dst, &args->src_stateid, restart);
                if (status)
                        goto out;
        }

        if ((!res->synchronous || !args->sync) &&
                        res->write_res.verifier.committed != NFS_FILE_SYNC) {
                status = process_copy_commit(dst, pos_dst, res);
                if (status)
                        goto out;
        }

        nfs42_copy_dest_done(dst, pos_dst, res->write_res.count, oldsize_dst);
        nfs_invalidate_atime(src_inode);
        status = res->write_res.count;
out:
        if (args->sync)
                kfree(res->commit_res.verf);
        return status;
}

ssize_t nfs42_proc_copy(struct file *src, loff_t pos_src,
                        struct file *dst, loff_t pos_dst, size_t count,
                        struct nl4_server *nss,
                        nfs4_stateid *cnr_stateid, bool sync)
{
        struct nfs_server *server = NFS_SERVER(file_inode(dst));
        struct nfs_lock_context *src_lock;
        struct nfs_lock_context *dst_lock;
        struct nfs42_copy_args args = {
                .src_fh         = NFS_FH(file_inode(src)),
                .src_pos        = pos_src,
                .dst_fh         = NFS_FH(file_inode(dst)),
                .dst_pos        = pos_dst,
                .count          = count,
                .sync           = sync,
        };
        struct nfs42_copy_res res;
        struct nfs4_exception src_exception = {
                .inode          = file_inode(src),
                .stateid        = &args.src_stateid,
        };
        struct nfs4_exception dst_exception = {
                .inode          = file_inode(dst),
                .stateid        = &args.dst_stateid,
        };
        ssize_t err, err2;
        bool restart = false;

        src_lock = nfs_get_lock_context(nfs_file_open_context(src));
        if (IS_ERR(src_lock))
                return PTR_ERR(src_lock);

        src_exception.state = src_lock->open_context->state;

        dst_lock = nfs_get_lock_context(nfs_file_open_context(dst));
        if (IS_ERR(dst_lock)) {
                err = PTR_ERR(dst_lock);
                goto out_put_src_lock;
        }

        dst_exception.state = dst_lock->open_context->state;

        do {
                inode_lock(file_inode(dst));
                err = _nfs42_proc_copy(src, src_lock,
                                dst, dst_lock,
                                &args, &res,
                                nss, cnr_stateid, &restart);
                inode_unlock(file_inode(dst));

                if (err >= 0)
                        break;
                if ((err == -ENOTSUPP ||
                                err == -NFS4ERR_OFFLOAD_DENIED) &&
                                nfs42_files_from_same_server(src, dst)) {
                        err = -EOPNOTSUPP;
                        break;
                } else if (err == -EAGAIN) {
                        if (!restart) {
                                dst_exception.retry = 1;
                                continue;
                        }
                        break;
                } else if (err == -NFS4ERR_OFFLOAD_NO_REQS &&
                                args.sync != res.synchronous) {
                        args.sync = res.synchronous;
                        dst_exception.retry = 1;
                        continue;
                } else if ((err == -ESTALE ||
                                err == -NFS4ERR_OFFLOAD_DENIED ||
                                err == -ENOTSUPP) &&
                                !nfs42_files_from_same_server(src, dst)) {
                        nfs42_do_offload_cancel_async(src, &args.src_stateid);
                        err = -EOPNOTSUPP;
                        break;
                }

                err2 = nfs4_handle_exception(server, err, &src_exception);
                err  = nfs4_handle_exception(server, err, &dst_exception);
                if (!err)
                        err = err2;
        } while (src_exception.retry || dst_exception.retry);

        nfs_put_lock_context(dst_lock);
out_put_src_lock:
        nfs_put_lock_context(src_lock);
        return err;
}

struct nfs42_offload_data {
        struct nfs_server *seq_server;
        struct nfs42_offload_status_args args;
        struct nfs42_offload_status_res res;
};

static void nfs42_offload_prepare(struct rpc_task *task, void *calldata)
{
        struct nfs42_offload_data *data = calldata;

        nfs4_setup_sequence(data->seq_server->nfs_client,
                                &data->args.osa_seq_args,
                                &data->res.osr_seq_res, task);
}

static void nfs42_offload_cancel_done(struct rpc_task *task, void *calldata)
{
        struct nfs42_offload_data *data = calldata;

        trace_nfs4_offload_cancel(&data->args, task->tk_status);
        nfs41_sequence_done(task, &data->res.osr_seq_res);
        if (task->tk_status &&
                nfs4_async_handle_error(task, data->seq_server, NULL,
                        NULL) == -EAGAIN)
                rpc_restart_call_prepare(task);
}

static void nfs42_offload_release(void *data)
{
        kfree(data);
}

static const struct rpc_call_ops nfs42_offload_cancel_ops = {
        .rpc_call_prepare = nfs42_offload_prepare,
        .rpc_call_done = nfs42_offload_cancel_done,
        .rpc_release = nfs42_offload_release,
};

static int nfs42_do_offload_cancel_async(struct file *dst,
                                         nfs4_stateid *stateid)
{
        struct nfs_server *dst_server = NFS_SERVER(file_inode(dst));
        struct nfs42_offload_data *data = NULL;
        struct nfs_open_context *ctx = nfs_file_open_context(dst);
        struct rpc_task *task;
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OFFLOAD_CANCEL],
                .rpc_cred = ctx->cred,
        };
        struct rpc_task_setup task_setup_data = {
                .rpc_client = dst_server->client,
                .rpc_message = &msg,
                .callback_ops = &nfs42_offload_cancel_ops,
                .workqueue = nfsiod_workqueue,
                .flags = RPC_TASK_ASYNC | RPC_TASK_MOVEABLE,
        };
        int status;

        if (!(dst_server->caps & NFS_CAP_OFFLOAD_CANCEL))
                return -EOPNOTSUPP;

        data = kzalloc_obj(struct nfs42_offload_data);
        if (data == NULL)
                return -ENOMEM;

        data->seq_server = dst_server;
        data->args.osa_src_fh = NFS_FH(file_inode(dst));
        memcpy(&data->args.osa_stateid, stateid,
                sizeof(data->args.osa_stateid));
        msg.rpc_argp = &data->args;
        msg.rpc_resp = &data->res;
        task_setup_data.callback_data = data;
        nfs4_init_sequence(dst_server->nfs_client, &data->args.osa_seq_args,
                           &data->res.osr_seq_res, 1, 0);
        task = rpc_run_task(&task_setup_data);
        if (IS_ERR(task))
                return PTR_ERR(task);
        status = rpc_wait_for_completion_task(task);
        if (status == -ENOTSUPP)
                dst_server->caps &= ~NFS_CAP_OFFLOAD_CANCEL;
        rpc_put_task(task);
        return status;
}

static int
_nfs42_proc_offload_status(struct nfs_server *server, struct file *file,
                           struct nfs42_offload_data *data)
{
        struct nfs_open_context *ctx = nfs_file_open_context(file);
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OFFLOAD_STATUS],
                .rpc_argp       = &data->args,
                .rpc_resp       = &data->res,
                .rpc_cred       = ctx->cred,
        };
        int status;

        status = nfs4_call_sync(server->client, server, &msg,
                                &data->args.osa_seq_args,
                                &data->res.osr_seq_res, 1);
        trace_nfs4_offload_status(&data->args, status);
        switch (status) {
        case 0:
                break;

        case -NFS4ERR_ADMIN_REVOKED:
        case -NFS4ERR_BAD_STATEID:
        case -NFS4ERR_OLD_STATEID:
                /*
                 * Server does not recognize the COPY stateid. CB_OFFLOAD
                 * could have purged it, or server might have rebooted.
                 * Since COPY stateids don't have an associated inode,
                 * avoid triggering state recovery.
                 */
                status = -EBADF;
                break;
        case -NFS4ERR_NOTSUPP:
        case -ENOTSUPP:
        case -EOPNOTSUPP:
                server->caps &= ~NFS_CAP_OFFLOAD_STATUS;
                status = -EOPNOTSUPP;
                break;
        }

        return status;
}

/**
 * nfs42_proc_offload_status - Poll completion status of an async copy operation
 * @dst: handle of file being copied into
 * @stateid: copy stateid (from async COPY result)
 * @copied: OUT: number of bytes copied so far
 *
 * Return values:
 *   %0: Server returned an NFS4_OK completion status
 *   %-EINPROGRESS: Server returned no completion status
 *   %-EREMOTEIO: Server returned an error completion status
 *   %-EBADF: Server did not recognize the copy stateid
 *   %-EOPNOTSUPP: Server does not support OFFLOAD_STATUS
 *   %-ERESTARTSYS: Wait interrupted by signal
 *
 * Other negative errnos indicate the client could not complete the
 * request.
 */
static int
nfs42_proc_offload_status(struct file *dst, nfs4_stateid *stateid, u64 *copied)
{
        struct inode *inode = file_inode(dst);
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs4_exception exception = {
                .inode = inode,
        };
        struct nfs42_offload_data *data;
        int status;

        if (!(server->caps & NFS_CAP_OFFLOAD_STATUS))
                return -EOPNOTSUPP;

        data = kzalloc_obj(*data);
        if (!data)
                return -ENOMEM;
        data->seq_server = server;
        data->args.osa_src_fh = NFS_FH(inode);
        memcpy(&data->args.osa_stateid, stateid,
                sizeof(data->args.osa_stateid));
        exception.stateid = &data->args.osa_stateid;
        do {
                status = _nfs42_proc_offload_status(server, dst, data);
                if (status == -EOPNOTSUPP)
                        goto out;
                status = nfs4_handle_exception(server, status, &exception);
        } while (exception.retry);
        if (status)
                goto out;

        *copied = data->res.osr_count;
        if (!data->res.complete_count)
                status = -EINPROGRESS;
        else if (data->res.osr_complete != NFS_OK)
                status = -EREMOTEIO;

out:
        kfree(data);
        return status;
}

static int _nfs42_proc_copy_notify(struct file *src, struct file *dst,
                                   struct nfs42_copy_notify_args *args,
                                   struct nfs42_copy_notify_res *res)
{
        struct nfs_server *src_server = NFS_SERVER(file_inode(src));
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COPY_NOTIFY],
                .rpc_argp = args,
                .rpc_resp = res,
        };
        int status;
        struct nfs_open_context *ctx;
        struct nfs_lock_context *l_ctx;

        ctx = get_nfs_open_context(nfs_file_open_context(src));
        l_ctx = nfs_get_lock_context(ctx);
        if (IS_ERR(l_ctx)) {
                status = PTR_ERR(l_ctx);
                goto out;
        }

        status = nfs4_set_rw_stateid(&args->cna_src_stateid, ctx, l_ctx,
                                     FMODE_READ);
        nfs_put_lock_context(l_ctx);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                goto out;
        }

        status = nfs4_call_sync(src_server->client, src_server, &msg,
                                &args->cna_seq_args, &res->cnr_seq_res, 0);
        trace_nfs4_copy_notify(file_inode(src), args, res, status);
        if (status == -ENOTSUPP)
                src_server->caps &= ~NFS_CAP_COPY_NOTIFY;

out:
        put_nfs_open_context(nfs_file_open_context(src));
        return status;
}

int nfs42_proc_copy_notify(struct file *src, struct file *dst,
                                struct nfs42_copy_notify_res *res)
{
        struct nfs_server *src_server = NFS_SERVER(file_inode(src));
        struct nfs42_copy_notify_args *args;
        struct nfs4_exception exception = {
                .inode = file_inode(src),
        };
        int status;

        if (!(src_server->caps & NFS_CAP_COPY_NOTIFY))
                return -EOPNOTSUPP;

        args = kzalloc_obj(struct nfs42_copy_notify_args);
        if (args == NULL)
                return -ENOMEM;

        args->cna_src_fh  = NFS_FH(file_inode(src)),
        args->cna_dst.nl4_type = NL4_NETADDR;
        nfs42_set_netaddr(dst, &args->cna_dst.u.nl4_addr);
        exception.stateid = &args->cna_src_stateid;

        do {
                status = _nfs42_proc_copy_notify(src, dst, args, res);
                if (status == -ENOTSUPP) {
                        status = -EOPNOTSUPP;
                        goto out;
                }
                status = nfs4_handle_exception(src_server, status, &exception);
        } while (exception.retry);

out:
        kfree(args);
        return status;
}

static loff_t _nfs42_proc_llseek(struct file *filep,
                struct nfs_lock_context *lock, loff_t offset, int whence)
{
        struct inode *inode = file_inode(filep);
        struct nfs42_seek_args args = {
                .sa_fh          = NFS_FH(inode),
                .sa_offset      = offset,
                .sa_what        = (whence == SEEK_HOLE) ?
                                        NFS4_CONTENT_HOLE : NFS4_CONTENT_DATA,
        };
        struct nfs42_seek_res res;
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SEEK],
                .rpc_argp = &args,
                .rpc_resp = &res,
        };
        struct nfs_server *server = NFS_SERVER(inode);
        int status;

        if (!nfs_server_capable(inode, NFS_CAP_SEEK))
                return -ENOTSUPP;

        status = nfs4_set_rw_stateid(&args.sa_stateid, lock->open_context,
                        lock, FMODE_READ);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                return status;
        }

        status = nfs_filemap_write_and_wait_range(inode->i_mapping,
                        offset, LLONG_MAX);
        if (status)
                return status;

        status = nfs4_call_sync(server->client, server, &msg,
                                &args.seq_args, &res.seq_res, 0);
        trace_nfs4_llseek(inode, &args, &res, status);
        if (status == -ENOTSUPP)
                server->caps &= ~NFS_CAP_SEEK;
        if (status)
                return status;

        if (whence == SEEK_DATA && res.sr_eof)
                return -NFS4ERR_NXIO;
        else
                return vfs_setpos(filep, res.sr_offset, inode->i_sb->s_maxbytes);
}

loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
{
        struct nfs_server *server = NFS_SERVER(file_inode(filep));
        struct nfs4_exception exception = { };
        struct nfs_lock_context *lock;
        loff_t err;

        lock = nfs_get_lock_context(nfs_file_open_context(filep));
        if (IS_ERR(lock))
                return PTR_ERR(lock);

        exception.inode = file_inode(filep);
        exception.state = lock->open_context->state;

        do {
                err = _nfs42_proc_llseek(filep, lock, offset, whence);
                if (err >= 0)
                        break;
                if (err == -ENOTSUPP) {
                        err = -EOPNOTSUPP;
                        break;
                }
                err = nfs4_handle_exception(server, err, &exception);
        } while (exception.retry);

        nfs_put_lock_context(lock);
        return err;
}


static void
nfs42_layoutstat_prepare(struct rpc_task *task, void *calldata)
{
        struct nfs42_layoutstat_data *data = calldata;
        struct inode *inode = data->inode;
        struct nfs_server *server = NFS_SERVER(inode);
        struct pnfs_layout_hdr *lo;

        spin_lock(&inode->i_lock);
        lo = NFS_I(inode)->layout;
        if (!pnfs_layout_is_valid(lo)) {
                spin_unlock(&inode->i_lock);
                rpc_exit(task, 0);
                return;
        }
        nfs4_stateid_copy(&data->args.stateid, &lo->plh_stateid);
        spin_unlock(&inode->i_lock);
        nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
                            &data->res.seq_res, task);
}

static void
nfs42_layoutstat_done(struct rpc_task *task, void *calldata)
{
        struct nfs42_layoutstat_data *data = calldata;
        struct inode *inode = data->inode;
        struct pnfs_layout_hdr *lo;

        if (!nfs4_sequence_done(task, &data->res.seq_res))
                return;

        switch (task->tk_status) {
        case 0:
                return;
        case -NFS4ERR_BADHANDLE:
        case -ESTALE:
                pnfs_destroy_layout(NFS_I(inode));
                break;
        case -NFS4ERR_EXPIRED:
        case -NFS4ERR_ADMIN_REVOKED:
        case -NFS4ERR_DELEG_REVOKED:
        case -NFS4ERR_STALE_STATEID:
        case -NFS4ERR_BAD_STATEID:
                spin_lock(&inode->i_lock);
                lo = NFS_I(inode)->layout;
                if (pnfs_layout_is_valid(lo) &&
                    nfs4_stateid_match(&data->args.stateid,
                                             &lo->plh_stateid)) {
                        LIST_HEAD(head);

                        /*
                         * Mark the bad layout state as invalid, then retry
                         * with the current stateid.
                         */
                        pnfs_mark_layout_stateid_invalid(lo, &head);
                        spin_unlock(&inode->i_lock);
                        pnfs_free_lseg_list(&head);
                        nfs_commit_inode(inode, 0);
                } else
                        spin_unlock(&inode->i_lock);
                break;
        case -NFS4ERR_OLD_STATEID:
                spin_lock(&inode->i_lock);
                lo = NFS_I(inode)->layout;
                if (pnfs_layout_is_valid(lo) &&
                    nfs4_stateid_match_other(&data->args.stateid,
                                        &lo->plh_stateid)) {
                        /* Do we need to delay before resending? */
                        if (!nfs4_stateid_is_newer(&lo->plh_stateid,
                                                &data->args.stateid))
                                rpc_delay(task, HZ);
                        rpc_restart_call_prepare(task);
                }
                spin_unlock(&inode->i_lock);
                break;
        case -ENOTSUPP:
        case -EOPNOTSUPP:
                NFS_SERVER(inode)->caps &= ~NFS_CAP_LAYOUTSTATS;
        }

        trace_nfs4_layoutstats(inode, &data->args.stateid, task->tk_status);
}

static void
nfs42_layoutstat_release(void *calldata)
{
        struct nfs42_layoutstat_data *data = calldata;
        struct nfs42_layoutstat_devinfo *devinfo = data->args.devinfo;
        int i;

        for (i = 0; i < data->args.num_dev; i++) {
                if (devinfo[i].ld_private.ops && devinfo[i].ld_private.ops->free)
                        devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
        }

        pnfs_put_layout_hdr(NFS_I(data->args.inode)->layout);
        smp_mb__before_atomic();
        clear_bit(NFS_INO_LAYOUTSTATS, &NFS_I(data->args.inode)->flags);
        smp_mb__after_atomic();
        nfs_iput_and_deactive(data->inode);
        kfree(data->args.devinfo);
        kfree(data);
}

static const struct rpc_call_ops nfs42_layoutstat_ops = {
        .rpc_call_prepare = nfs42_layoutstat_prepare,
        .rpc_call_done = nfs42_layoutstat_done,
        .rpc_release = nfs42_layoutstat_release,
};

int nfs42_proc_layoutstats_generic(struct nfs_server *server,
                                   struct nfs42_layoutstat_data *data)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTSTATS],
                .rpc_argp = &data->args,
                .rpc_resp = &data->res,
        };
        struct rpc_task_setup task_setup = {
                .rpc_client = server->client,
                .rpc_message = &msg,
                .callback_ops = &nfs42_layoutstat_ops,
                .callback_data = data,
                .flags = RPC_TASK_ASYNC | RPC_TASK_MOVEABLE,
        };
        struct rpc_task *task;

        data->inode = nfs_igrab_and_active(data->args.inode);
        if (!data->inode) {
                nfs42_layoutstat_release(data);
                return -EAGAIN;
        }
        nfs4_init_sequence(server->nfs_client, &data->args.seq_args,
                           &data->res.seq_res, 0, 0);
        task = rpc_run_task(&task_setup);
        if (IS_ERR(task))
                return PTR_ERR(task);
        rpc_put_task(task);
        return 0;
}

static struct nfs42_layouterror_data *
nfs42_alloc_layouterror_data(struct pnfs_layout_segment *lseg, gfp_t gfp_flags)
{
        struct nfs42_layouterror_data *data;
        struct inode *inode = lseg->pls_layout->plh_inode;

        data = kzalloc_obj(*data, gfp_flags);
        if (data) {
                data->args.inode = data->inode = nfs_igrab_and_active(inode);
                if (data->inode) {
                        data->lseg = pnfs_get_lseg(lseg);
                        if (data->lseg)
                                return data;
                        nfs_iput_and_deactive(data->inode);
                }
                kfree(data);
        }
        return NULL;
}

static void
nfs42_free_layouterror_data(struct nfs42_layouterror_data *data)
{
        pnfs_put_lseg(data->lseg);
        nfs_iput_and_deactive(data->inode);
        kfree(data);
}

static void
nfs42_layouterror_prepare(struct rpc_task *task, void *calldata)
{
        struct nfs42_layouterror_data *data = calldata;
        struct inode *inode = data->inode;
        struct nfs_server *server = NFS_SERVER(inode);
        struct pnfs_layout_hdr *lo = data->lseg->pls_layout;
        unsigned i;

        spin_lock(&inode->i_lock);
        if (!pnfs_layout_is_valid(lo)) {
                spin_unlock(&inode->i_lock);
                rpc_exit(task, 0);
                return;
        }
        for (i = 0; i < data->args.num_errors; i++)
                nfs4_stateid_copy(&data->args.errors[i].stateid,
                                &lo->plh_stateid);
        spin_unlock(&inode->i_lock);
        nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
                            &data->res.seq_res, task);
}

static void
nfs42_layouterror_done(struct rpc_task *task, void *calldata)
{
        struct nfs42_layouterror_data *data = calldata;
        struct inode *inode = data->inode;
        struct pnfs_layout_hdr *lo = data->lseg->pls_layout;

        if (!nfs4_sequence_done(task, &data->res.seq_res))
                return;

        switch (task->tk_status) {
        case 0:
                return;
        case -NFS4ERR_BADHANDLE:
        case -ESTALE:
                pnfs_destroy_layout(NFS_I(inode));
                break;
        case -NFS4ERR_EXPIRED:
        case -NFS4ERR_ADMIN_REVOKED:
        case -NFS4ERR_DELEG_REVOKED:
        case -NFS4ERR_STALE_STATEID:
        case -NFS4ERR_BAD_STATEID:
                spin_lock(&inode->i_lock);
                if (pnfs_layout_is_valid(lo) &&
                    nfs4_stateid_match(&data->args.errors[0].stateid,
                                             &lo->plh_stateid)) {
                        LIST_HEAD(head);

                        /*
                         * Mark the bad layout state as invalid, then retry
                         * with the current stateid.
                         */
                        pnfs_mark_layout_stateid_invalid(lo, &head);
                        spin_unlock(&inode->i_lock);
                        pnfs_free_lseg_list(&head);
                        nfs_commit_inode(inode, 0);
                } else
                        spin_unlock(&inode->i_lock);
                break;
        case -NFS4ERR_OLD_STATEID:
                spin_lock(&inode->i_lock);
                if (pnfs_layout_is_valid(lo) &&
                    nfs4_stateid_match_other(&data->args.errors[0].stateid,
                                        &lo->plh_stateid)) {
                        /* Do we need to delay before resending? */
                        if (!nfs4_stateid_is_newer(&lo->plh_stateid,
                                                &data->args.errors[0].stateid))
                                rpc_delay(task, HZ);
                        rpc_restart_call_prepare(task);
                }
                spin_unlock(&inode->i_lock);
                break;
        case -ENOTSUPP:
        case -EOPNOTSUPP:
                NFS_SERVER(inode)->caps &= ~NFS_CAP_LAYOUTERROR;
        }

        trace_nfs4_layouterror(inode, &data->args.errors[0].stateid,
                               task->tk_status);
}

static void
nfs42_layouterror_release(void *calldata)
{
        struct nfs42_layouterror_data *data = calldata;

        nfs42_free_layouterror_data(data);
}

static const struct rpc_call_ops nfs42_layouterror_ops = {
        .rpc_call_prepare = nfs42_layouterror_prepare,
        .rpc_call_done = nfs42_layouterror_done,
        .rpc_release = nfs42_layouterror_release,
};

int nfs42_proc_layouterror(struct pnfs_layout_segment *lseg,
                const struct nfs42_layout_error *errors, size_t n)
{
        struct inode *inode = lseg->pls_layout->plh_inode;
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs42_layouterror_data *data;
        struct rpc_task *task;
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTERROR],
        };
        struct rpc_task_setup task_setup = {
                .rpc_message = &msg,
                .callback_ops = &nfs42_layouterror_ops,
                .flags = RPC_TASK_ASYNC | RPC_TASK_MOVEABLE,
        };
        unsigned int i;

        if (!nfs_server_capable(inode, NFS_CAP_LAYOUTERROR))
                return -EOPNOTSUPP;
        if (n > NFS42_LAYOUTERROR_MAX)
                return -EINVAL;
        data = nfs42_alloc_layouterror_data(lseg, nfs_io_gfp_mask());
        if (!data)
                return -ENOMEM;
        for (i = 0; i < n; i++) {
                data->args.errors[i] = errors[i];
                data->args.num_errors++;
                data->res.num_errors++;
        }
        msg.rpc_argp = &data->args;
        msg.rpc_resp = &data->res;
        task_setup.callback_data = data;
        task_setup.rpc_client = server->client;
        nfs4_init_sequence(server->nfs_client, &data->args.seq_args,
                           &data->res.seq_res, 0, 0);
        task = rpc_run_task(&task_setup);
        if (IS_ERR(task))
                return PTR_ERR(task);
        rpc_put_task(task);
        return 0;
}
EXPORT_SYMBOL_GPL(nfs42_proc_layouterror);

static int _nfs42_proc_clone(struct rpc_message *msg, struct file *src_f,
                struct file *dst_f, struct nfs_lock_context *src_lock,
                struct nfs_lock_context *dst_lock, loff_t src_offset,
                loff_t dst_offset, loff_t count)
{
        struct inode *src_inode = file_inode(src_f);
        struct inode *dst_inode = file_inode(dst_f);
        struct nfs_server *server = NFS_SERVER(dst_inode);
        __u32 dst_bitmask[NFS_BITMASK_SZ];
        struct nfs42_clone_args args = {
                .src_fh = NFS_FH(src_inode),
                .dst_fh = NFS_FH(dst_inode),
                .src_offset = src_offset,
                .dst_offset = dst_offset,
                .count = count,
                .dst_bitmask = dst_bitmask,
        };
        struct nfs42_clone_res res = {
                .server = server,
        };
        loff_t oldsize_dst = i_size_read(dst_inode);
        int status;

        msg->rpc_argp = &args;
        msg->rpc_resp = &res;

        status = nfs4_set_rw_stateid(&args.src_stateid, src_lock->open_context,
                        src_lock, FMODE_READ);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                return status;
        }
        status = nfs4_set_rw_stateid(&args.dst_stateid, dst_lock->open_context,
                        dst_lock, FMODE_WRITE);
        if (status) {
                if (status == -EAGAIN)
                        status = -NFS4ERR_BAD_STATEID;
                return status;
        }

        res.dst_fattr = nfs_alloc_fattr();
        if (!res.dst_fattr)
                return -ENOMEM;

        nfs4_bitmask_set(dst_bitmask, server->cache_consistency_bitmask,
                         dst_inode, NFS_INO_INVALID_BLOCKS);

        status = nfs4_call_sync(server->client, server, msg,
                                &args.seq_args, &res.seq_res, 0);
        trace_nfs4_clone(src_inode, dst_inode, &args, status);
        if (status == 0) {
                /* a zero-length count means clone to EOF in src */
                if (count == 0 && res.dst_fattr->valid & NFS_ATTR_FATTR_SIZE)
                        count = nfs_size_to_loff_t(res.dst_fattr->size) - dst_offset;
                nfs42_copy_dest_done(dst_f, dst_offset, count, oldsize_dst);
                status = nfs_post_op_update_inode(dst_inode, res.dst_fattr);
        }

        kfree(res.dst_fattr);
        return status;
}

int nfs42_proc_clone(struct file *src_f, struct file *dst_f,
                     loff_t src_offset, loff_t dst_offset, loff_t count)
{
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLONE],
        };
        struct inode *inode = file_inode(src_f);
        struct nfs_server *server = NFS_SERVER(file_inode(src_f));
        struct nfs_lock_context *src_lock;
        struct nfs_lock_context *dst_lock;
        struct nfs4_exception src_exception = { };
        struct nfs4_exception dst_exception = { };
        int err, err2;

        if (!nfs_server_capable(inode, NFS_CAP_CLONE))
                return -EOPNOTSUPP;

        src_lock = nfs_get_lock_context(nfs_file_open_context(src_f));
        if (IS_ERR(src_lock))
                return PTR_ERR(src_lock);

        src_exception.inode = file_inode(src_f);
        src_exception.state = src_lock->open_context->state;

        dst_lock = nfs_get_lock_context(nfs_file_open_context(dst_f));
        if (IS_ERR(dst_lock)) {
                err = PTR_ERR(dst_lock);
                goto out_put_src_lock;
        }

        dst_exception.inode = file_inode(dst_f);
        dst_exception.state = dst_lock->open_context->state;

        do {
                err = _nfs42_proc_clone(&msg, src_f, dst_f, src_lock, dst_lock,
                                        src_offset, dst_offset, count);
                if (err == -ENOTSUPP || err == -EOPNOTSUPP) {
                        NFS_SERVER(inode)->caps &= ~NFS_CAP_CLONE;
                        err = -EOPNOTSUPP;
                        break;
                }

                err2 = nfs4_handle_exception(server, err, &src_exception);
                err = nfs4_handle_exception(server, err, &dst_exception);
                if (!err)
                        err = err2;
        } while (src_exception.retry || dst_exception.retry);

        nfs_put_lock_context(dst_lock);
out_put_src_lock:
        nfs_put_lock_context(src_lock);
        return err;
}

#define NFS4XATTR_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE)

static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
{
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs42_removexattrargs args = {
                .fh = NFS_FH(inode),
                .xattr_name = name,
        };
        struct nfs42_removexattrres res;
        struct rpc_message msg = {
                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVEXATTR],
                .rpc_argp = &args,
                .rpc_resp = &res,
        };
        int ret;
        unsigned long timestamp = jiffies;

        ret = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
            &res.seq_res, 1);
        trace_nfs4_removexattr(inode, name, ret);
        if (!ret)
                nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);

        return ret;
}

static int _nfs42_proc_setxattr(struct inode *inode, const char *name,
                                const void *buf, size_t buflen, int flags)
{
        struct nfs_server *server = NFS_SERVER(inode);
        __u32 bitmask[NFS_BITMASK_SZ];
        struct page *pages[NFS4XATTR_MAXPAGES];
        struct nfs42_setxattrargs arg = {
                .fh             = NFS_FH(inode),
                .bitmask        = bitmask,
                .xattr_pages    = pages,
                .xattr_len      = buflen,
                .xattr_name     = name,
                .xattr_flags    = flags,
        };
        struct nfs42_setxattrres res = {
                .server         = server,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_SETXATTR],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        int ret, np;
        unsigned long timestamp = jiffies;

        if (buflen > server->sxasize)
                return -ERANGE;

        res.fattr = nfs_alloc_fattr();
        if (!res.fattr)
                return -ENOMEM;

        if (buflen > 0) {
                np = nfs4_buf_to_pages_noslab(buf, buflen, arg.xattr_pages);
                if (np < 0) {
                        ret = np;
                        goto out;
                }
        } else
                np = 0;

        nfs4_bitmask_set(bitmask, server->cache_consistency_bitmask,
                         inode, NFS_INO_INVALID_CHANGE);

        ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
            &res.seq_res, 1);
        trace_nfs4_setxattr(inode, name, ret);

        for (; np > 0; np--)
                put_page(pages[np - 1]);

        if (!ret) {
                nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
                ret = nfs_post_op_update_inode(inode, res.fattr);
        }

out:
        kfree(res.fattr);
        return ret;
}

static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name,
                                void *buf, size_t buflen, struct page **pages,
                                size_t plen)
{
        struct nfs_server *server = NFS_SERVER(inode);
        struct nfs42_getxattrargs arg = {
                .fh             = NFS_FH(inode),
                .xattr_name     = name,
        };
        struct nfs42_getxattrres res;
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_GETXATTR],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        ssize_t ret;

        arg.xattr_len = plen;
        arg.xattr_pages = pages;

        ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
            &res.seq_res, 0);
        trace_nfs4_getxattr(inode, name, ret);
        if (ret < 0)
                return ret;

        /*
         * Normally, the caching is done one layer up, but for successful
         * RPCS, always cache the result here, even if the caller was
         * just querying the length, or if the reply was too big for
         * the caller. This avoids a second RPC in the case of the
         * common query-alloc-retrieve cycle for xattrs.
         *
         * Note that xattr_len is always capped to XATTR_SIZE_MAX.
         */

        nfs4_xattr_cache_add(inode, name, NULL, pages, res.xattr_len);

        if (buflen) {
                if (res.xattr_len > buflen)
                        return -ERANGE;
                _copy_from_pages(buf, pages, 0, res.xattr_len);
        }

        return res.xattr_len;
}

static ssize_t _nfs42_proc_listxattrs(struct inode *inode, void *buf,
                                 size_t buflen, u64 *cookiep, bool *eofp)
{
        struct nfs_server *server = NFS_SERVER(inode);
        struct page **pages;
        struct nfs42_listxattrsargs arg = {
                .fh             = NFS_FH(inode),
                .cookie         = *cookiep,
        };
        struct nfs42_listxattrsres res = {
                .eof = false,
                .xattr_buf = buf,
                .xattr_len = buflen,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_LISTXATTRS],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        u32 xdrlen;
        int ret, np, i;


        ret = -ENOMEM;
        res.scratch = folio_alloc(GFP_KERNEL, 0);
        if (!res.scratch)
                goto out;

        xdrlen = nfs42_listxattr_xdrsize(buflen);
        if (xdrlen > server->lxasize)
                xdrlen = server->lxasize;
        np = xdrlen / PAGE_SIZE + 1;

        pages = kzalloc_objs(struct page *, np);
        if (!pages)
                goto out_free_scratch;
        for (i = 0; i < np; i++) {
                pages[i] = alloc_page(GFP_KERNEL);
                if (!pages[i])
                        goto out_free_pages;
        }

        arg.xattr_pages = pages;
        arg.count = xdrlen;

        ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
            &res.seq_res, 0);
        trace_nfs4_listxattr(inode, ret);

        if (ret >= 0) {
                ret = res.copied;
                *cookiep = res.cookie;
                *eofp = res.eof;
        }

out_free_pages:
        while (--np >= 0) {
                if (pages[np])
                        __free_page(pages[np]);
        }
        kfree(pages);
out_free_scratch:
        folio_put(res.scratch);
out:
        return ret;

}

ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
                              void *buf, size_t buflen)
{
        struct nfs4_exception exception = { };
        ssize_t err, np, i;
        struct page **pages;

        np = nfs_page_array_len(0, buflen ?: XATTR_SIZE_MAX);
        pages = kmalloc_objs(*pages, np);
        if (!pages)
                return -ENOMEM;

        for (i = 0; i < np; i++) {
                pages[i] = alloc_page(GFP_KERNEL);
                if (!pages[i]) {
                        err = -ENOMEM;
                        goto out;
                }
        }

        /*
         * The GETXATTR op has no length field in the call, and the
         * xattr data is at the end of the reply.
         *
         * There is no downside in using the page-aligned length. It will
         * allow receiving and caching xattrs that are too large for the
         * caller but still fit in the page-rounded value.
         */
        do {
                err = _nfs42_proc_getxattr(inode, name, buf, buflen,
                        pages, np * PAGE_SIZE);
                if (err >= 0)
                        break;
                err = nfs4_handle_exception(NFS_SERVER(inode), err,
                                &exception);
        } while (exception.retry);

out:
        while (--i >= 0)
                __free_page(pages[i]);
        kfree(pages);

        return err;
}

int nfs42_proc_setxattr(struct inode *inode, const char *name,
                              const void *buf, size_t buflen, int flags)
{
        struct nfs4_exception exception = { };
        int err;

        do {
                err = _nfs42_proc_setxattr(inode, name, buf, buflen, flags);
                if (!err)
                        break;
                err = nfs4_handle_exception(NFS_SERVER(inode), err,
                                &exception);
        } while (exception.retry);

        return err;
}

ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
                              size_t buflen, u64 *cookiep, bool *eofp)
{
        struct nfs4_exception exception = { };
        ssize_t err;

        do {
                err = _nfs42_proc_listxattrs(inode, buf, buflen,
                    cookiep, eofp);
                if (err >= 0)
                        break;
                err = nfs4_handle_exception(NFS_SERVER(inode), err,
                                &exception);
        } while (exception.retry);

        return err;
}

int nfs42_proc_removexattr(struct inode *inode, const char *name)
{
        struct nfs4_exception exception = { };
        int err;

        do {
                err = _nfs42_proc_removexattr(inode, name);
                if (!err)
                        break;
                err = nfs4_handle_exception(NFS_SERVER(inode), err,
                                &exception);
        } while (exception.retry);

        return err;
}