/*
 *  SMB2 version specific operations
 *
 *  Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
 *
 *  This library is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License v2 as published
 *  by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *  the GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/pagemap.h>
#include <linux/vfs.h>
#include <linux/falloc.h>
#include <linux/scatterlist.h>
#include <linux/uuid.h>
#include <crypto/aead.h>
#include "cifsglob.h"
#include "smb2pdu.h"
#include "smb2proto.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "smb2status.h"
#include "smb2glob.h"
#include "cifs_ioctl.h"
#include "smbdirect.h"

/* Change credits for different ops and return the total number of credits */
static int
change_conf(struct TCP_Server_Info *server)
{
        server->credits += server->echo_credits + server->oplock_credits;
        server->oplock_credits = server->echo_credits = 0;
        switch (server->credits) {
        case 0:
                return 0;
        case 1:
                server->echoes = false;
                server->oplocks = false;
                break;
        case 2:
                server->echoes = true;
                server->oplocks = false;
                server->echo_credits = 1;
                break;
        default:
                server->echoes = true;
                if (enable_oplocks) {
                        server->oplocks = true;
                        server->oplock_credits = 1;
                } else
                        server->oplocks = false;

                server->echo_credits = 1;
        }
        server->credits -= server->echo_credits + server->oplock_credits;
        return server->credits + server->echo_credits + server->oplock_credits;
}

static void
smb2_add_credits(struct TCP_Server_Info *server,
                 const struct cifs_credits *credits, const int optype)
{
        int *val, rc = -1;
        unsigned int add = credits->value;
        unsigned int instance = credits->instance;
        bool reconnect_detected = false;

        spin_lock(&server->req_lock);
        val = server->ops->get_credits_field(server, optype);

        /* eg found case where write overlapping reconnect messed up credits */
        if (((optype & CIFS_OP_MASK) == CIFS_NEG_OP) && (*val != 0))
                trace_smb3_reconnect_with_invalid_credits(server->CurrentMid,
                        server->hostname, *val);
        if ((instance == 0) || (instance == server->reconnect_instance))
                *val += add;
        else
                reconnect_detected = true;

        if (*val > 65000) {
                *val = 65000; /* Don't get near 64K credits, avoid srv bugs */
                printk_once(KERN_WARNING "server overflowed SMB3 credits\n");
        }
        server->in_flight--;
        if (server->in_flight == 0 && (optype & CIFS_OP_MASK) != CIFS_NEG_OP)
                rc = change_conf(server);
        /*
         * Sometimes server returns 0 credits on oplock break ack - we need to
         * rebalance credits in this case.
         */
        else if (server->in_flight > 0 && server->oplock_credits == 0 &&
                 server->oplocks) {
                if (server->credits > 1) {
                        server->credits--;
                        server->oplock_credits++;
                }
        }
        spin_unlock(&server->req_lock);
        wake_up(&server->request_q);

        if (reconnect_detected)
                cifs_dbg(FYI, "trying to put %d credits from the old server instance %d\n",
                         add, instance);

        if (server->tcpStatus == CifsNeedReconnect
            || server->tcpStatus == CifsExiting)
                return;

        switch (rc) {
        case -1:
                /* change_conf hasn't been executed */
                break;
        case 0:
                cifs_dbg(VFS, "Possible client or server bug - zero credits\n");
                break;
        case 1:
                cifs_dbg(VFS, "disabling echoes and oplocks\n");
                break;
        case 2:
                cifs_dbg(FYI, "disabling oplocks\n");
                break;
        default:
                cifs_dbg(FYI, "add %u credits total=%d\n", add, rc);
        }
}

static void
smb2_set_credits(struct TCP_Server_Info *server, const int val)
{
        spin_lock(&server->req_lock);
        server->credits = val;
        if (val == 1)
                server->reconnect_instance++;
        spin_unlock(&server->req_lock);
        /* don't log while holding the lock */
        if (val == 1)
                cifs_dbg(FYI, "set credits to 1 due to smb2 reconnect\n");
}

static int *
smb2_get_credits_field(struct TCP_Server_Info *server, const int optype)
{
        switch (optype) {
        case CIFS_ECHO_OP:
                return &server->echo_credits;
        case CIFS_OBREAK_OP:
                return &server->oplock_credits;
        default:
                return &server->credits;
        }
}

static unsigned int
smb2_get_credits(struct mid_q_entry *mid)
{
        struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)mid->resp_buf;

        if (mid->mid_state == MID_RESPONSE_RECEIVED
            || mid->mid_state == MID_RESPONSE_MALFORMED)
                return le16_to_cpu(shdr->CreditRequest);

        return 0;
}

static int
smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
                      unsigned int *num, struct cifs_credits *credits)
{
        int rc = 0;
        unsigned int scredits;

        spin_lock(&server->req_lock);
        while (1) {
                if (server->credits <= 0) {
                        spin_unlock(&server->req_lock);
                        cifs_num_waiters_inc(server);
                        rc = wait_event_killable(server->request_q,
                                has_credits(server, &server->credits, 1));
                        cifs_num_waiters_dec(server);
                        if (rc)
                                return rc;
                        spin_lock(&server->req_lock);
                } else {
                        if (server->tcpStatus == CifsExiting) {
                                spin_unlock(&server->req_lock);
                                return -ENOENT;
                        }

                        scredits = server->credits;
                        /* can deadlock with reopen */
                        if (scredits <= 8) {
                                *num = SMB2_MAX_BUFFER_SIZE;
                                credits->value = 0;
                                credits->instance = 0;
                                break;
                        }

                        /* leave some credits for reopen and other ops */
                        scredits -= 8;
                        *num = min_t(unsigned int, size,
                                     scredits * SMB2_MAX_BUFFER_SIZE);

                        credits->value =
                                DIV_ROUND_UP(*num, SMB2_MAX_BUFFER_SIZE);
                        credits->instance = server->reconnect_instance;
                        server->credits -= credits->value;
                        server->in_flight++;
                        break;
                }
        }
        spin_unlock(&server->req_lock);
        return rc;
}

static int
smb2_adjust_credits(struct TCP_Server_Info *server,
                    struct cifs_credits *credits,
                    const unsigned int payload_size)
{
        int new_val = DIV_ROUND_UP(payload_size, SMB2_MAX_BUFFER_SIZE);

        if (!credits->value || credits->value == new_val)
                return 0;

        if (credits->value < new_val) {
                WARN_ONCE(1, "request has less credits (%d) than required (%d)",
                          credits->value, new_val);
                return -ENOTSUPP;
        }

        spin_lock(&server->req_lock);

        if (server->reconnect_instance != credits->instance) {
                spin_unlock(&server->req_lock);
                cifs_dbg(VFS, "trying to return %d credits to old session\n",
                         credits->value - new_val);
                return -EAGAIN;
        }

        server->credits += credits->value - new_val;
        spin_unlock(&server->req_lock);
        wake_up(&server->request_q);
        credits->value = new_val;
        return 0;
}

static __u64
smb2_get_next_mid(struct TCP_Server_Info *server)
{
        __u64 mid;
        /* for SMB2 we need the current value */
        spin_lock(&GlobalMid_Lock);
        mid = server->CurrentMid++;
        spin_unlock(&GlobalMid_Lock);
        return mid;
}

static void
smb2_revert_current_mid(struct TCP_Server_Info *server, const unsigned int val)
{
        spin_lock(&GlobalMid_Lock);
        if (server->CurrentMid >= val)
                server->CurrentMid -= val;
        spin_unlock(&GlobalMid_Lock);
}

static struct mid_q_entry *
smb2_find_mid(struct TCP_Server_Info *server, char *buf)
{
        struct mid_q_entry *mid;
        struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;
        __u64 wire_mid = le64_to_cpu(shdr->MessageId);

        if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
                cifs_dbg(VFS, "encrypted frame parsing not supported yet");
                return NULL;
        }

        spin_lock(&GlobalMid_Lock);
        list_for_each_entry(mid, &server->pending_mid_q, qhead) {
                if ((mid->mid == wire_mid) &&
                    (mid->mid_state == MID_REQUEST_SUBMITTED) &&
                    (mid->command == shdr->Command)) {
                        kref_get(&mid->refcount);
                        spin_unlock(&GlobalMid_Lock);
                        return mid;
                }
        }
        spin_unlock(&GlobalMid_Lock);
        return NULL;
}

static void
smb2_dump_detail(void *buf, struct TCP_Server_Info *server)
{
#ifdef CONFIG_CIFS_DEBUG2
        struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;

        cifs_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d\n",
                 shdr->Command, shdr->Status, shdr->Flags, shdr->MessageId,
                 shdr->ProcessId);
        cifs_dbg(VFS, "smb buf %p len %u\n", buf,
                 server->ops->calc_smb_size(buf, server));
#endif
}

static bool
smb2_need_neg(struct TCP_Server_Info *server)
{
        return server->max_read == 0;
}

static int
smb2_negotiate(const unsigned int xid, struct cifs_ses *ses)
{
        int rc;
        ses->server->CurrentMid = 0;
        rc = SMB2_negotiate(xid, ses);
        /* BB we probably don't need to retry with modern servers */
        if (rc == -EAGAIN)
                rc = -EHOSTDOWN;
        return rc;
}

static unsigned int
smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
        struct TCP_Server_Info *server = tcon->ses->server;
        unsigned int wsize;

        /* start with specified wsize, or default */
        wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
        wsize = min_t(unsigned int, wsize, server->max_write);
#ifdef CONFIG_CIFS_SMB_DIRECT
        if (server->rdma) {
                if (server->sign)
                        wsize = min_t(unsigned int,
                                wsize, server->smbd_conn->max_fragmented_send_size);
                else
                        wsize = min_t(unsigned int,
                                wsize, server->smbd_conn->max_readwrite_size);
        }
#endif
        if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
                wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);

        return wsize;
}

static unsigned int
smb3_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
        struct TCP_Server_Info *server = tcon->ses->server;
        unsigned int wsize;

        /* start with specified wsize, or default */
        wsize = volume_info->wsize ? volume_info->wsize : SMB3_DEFAULT_IOSIZE;
        wsize = min_t(unsigned int, wsize, server->max_write);
#ifdef CONFIG_CIFS_SMB_DIRECT
        if (server->rdma) {
                if (server->sign)
                        wsize = min_t(unsigned int,
                                wsize, server->smbd_conn->max_fragmented_send_size);
                else
                        wsize = min_t(unsigned int,
                                wsize, server->smbd_conn->max_readwrite_size);
        }
#endif
        if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
                wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);

        return wsize;
}

static unsigned int
smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
        struct TCP_Server_Info *server = tcon->ses->server;
        unsigned int rsize;

        /* start with specified rsize, or default */
        rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
        rsize = min_t(unsigned int, rsize, server->max_read);
#ifdef CONFIG_CIFS_SMB_DIRECT
        if (server->rdma) {
                if (server->sign)
                        rsize = min_t(unsigned int,
                                rsize, server->smbd_conn->max_fragmented_recv_size);
                else
                        rsize = min_t(unsigned int,
                                rsize, server->smbd_conn->max_readwrite_size);
        }
#endif

        if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
                rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);

        return rsize;
}

static unsigned int
smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
        struct TCP_Server_Info *server = tcon->ses->server;
        unsigned int rsize;

        /* start with specified rsize, or default */
        rsize = volume_info->rsize ? volume_info->rsize : SMB3_DEFAULT_IOSIZE;
        rsize = min_t(unsigned int, rsize, server->max_read);
#ifdef CONFIG_CIFS_SMB_DIRECT
        if (server->rdma) {
                if (server->sign)
                        rsize = min_t(unsigned int,
                                rsize, server->smbd_conn->max_fragmented_recv_size);
                else
                        rsize = min_t(unsigned int,
                                rsize, server->smbd_conn->max_readwrite_size);
        }
#endif

        if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
                rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);

        return rsize;
}

static int
parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
                        size_t buf_len,
                        struct cifs_server_iface **iface_list,
                        size_t *iface_count)
{
        struct network_interface_info_ioctl_rsp *p;
        struct sockaddr_in *addr4;
        struct sockaddr_in6 *addr6;
        struct iface_info_ipv4 *p4;
        struct iface_info_ipv6 *p6;
        struct cifs_server_iface *info;
        ssize_t bytes_left;
        size_t next = 0;
        int nb_iface = 0;
        int rc = 0;

        *iface_list = NULL;
        *iface_count = 0;

        /*
         * Fist pass: count and sanity check
         */

        bytes_left = buf_len;
        p = buf;
        while (bytes_left >= sizeof(*p)) {
                nb_iface++;
                next = le32_to_cpu(p->Next);
                if (!next) {
                        bytes_left -= sizeof(*p);
                        break;
                }
                p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next);
                bytes_left -= next;
        }

        if (!nb_iface) {
                cifs_dbg(VFS, "%s: malformed interface info\n", __func__);
                rc = -EINVAL;
                goto out;
        }

        if (bytes_left || p->Next)
                cifs_dbg(VFS, "%s: incomplete interface info\n", __func__);


        /*
         * Second pass: extract info to internal structure
         */

        *iface_list = kcalloc(nb_iface, sizeof(**iface_list), GFP_KERNEL);
        if (!*iface_list) {
                rc = -ENOMEM;
                goto out;
        }

        info = *iface_list;
        bytes_left = buf_len;
        p = buf;
        while (bytes_left >= sizeof(*p)) {
                info->speed = le64_to_cpu(p->LinkSpeed);
                info->rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE);
                info->rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE);

                cifs_dbg(FYI, "%s: adding iface %zu\n", __func__, *iface_count);
                cifs_dbg(FYI, "%s: speed %zu bps\n", __func__, info->speed);
                cifs_dbg(FYI, "%s: capabilities 0x%08x\n", __func__,
                         le32_to_cpu(p->Capability));

                switch (p->Family) {
                /*
                 * The kernel and wire socket structures have the same
                 * layout and use network byte order but make the
                 * conversion explicit in case either one changes.
                 */
                case INTERNETWORK:
                        addr4 = (struct sockaddr_in *)&info->sockaddr;
                        p4 = (struct iface_info_ipv4 *)p->Buffer;
                        addr4->sin_family = AF_INET;
                        memcpy(&addr4->sin_addr, &p4->IPv4Address, 4);

                        /* [MS-SMB2] 2.2.32.5.1.1 Clients MUST ignore these */
                        addr4->sin_port = cpu_to_be16(CIFS_PORT);

                        cifs_dbg(FYI, "%s: ipv4 %pI4\n", __func__,
                                 &addr4->sin_addr);
                        break;
                case INTERNETWORKV6:
                        addr6 = (struct sockaddr_in6 *)&info->sockaddr;
                        p6 = (struct iface_info_ipv6 *)p->Buffer;
                        addr6->sin6_family = AF_INET6;
                        memcpy(&addr6->sin6_addr, &p6->IPv6Address, 16);

                        /* [MS-SMB2] 2.2.32.5.1.2 Clients MUST ignore these */
                        addr6->sin6_flowinfo = 0;
                        addr6->sin6_scope_id = 0;
                        addr6->sin6_port = cpu_to_be16(CIFS_PORT);

                        cifs_dbg(FYI, "%s: ipv6 %pI6\n", __func__,
                                 &addr6->sin6_addr);
                        break;
                default:
                        cifs_dbg(VFS,
                                 "%s: skipping unsupported socket family\n",
                                 __func__);
                        goto next_iface;
                }

                (*iface_count)++;
                info++;
next_iface:
                next = le32_to_cpu(p->Next);
                if (!next)
                        break;
                p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next);
                bytes_left -= next;
        }

        if (!*iface_count) {
                rc = -EINVAL;
                goto out;
        }

out:
        if (rc) {
                kfree(*iface_list);
                *iface_count = 0;
                *iface_list = NULL;
        }
        return rc;
}


static int
SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
{
        int rc;
        unsigned int ret_data_len = 0;
        struct network_interface_info_ioctl_rsp *out_buf = NULL;
        struct cifs_server_iface *iface_list;
        size_t iface_count;
        struct cifs_ses *ses = tcon->ses;

        rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
                        FSCTL_QUERY_NETWORK_INTERFACE_INFO, true /* is_fsctl */,
                        NULL /* no data input */, 0 /* no data input */,
                        CIFSMaxBufSize, (char **)&out_buf, &ret_data_len);
        if (rc == -EOPNOTSUPP) {
                cifs_dbg(FYI,
                         "server does not support query network interfaces\n");
                goto out;
        } else if (rc != 0) {
                cifs_dbg(VFS, "error %d on ioctl to get interface list\n", rc);
                goto out;
        }

        rc = parse_server_interfaces(out_buf, ret_data_len,
                                     &iface_list, &iface_count);
        if (rc)
                goto out;

        spin_lock(&ses->iface_lock);
        kfree(ses->iface_list);
        ses->iface_list = iface_list;
        ses->iface_count = iface_count;
        ses->iface_last_update = jiffies;
        spin_unlock(&ses->iface_lock);

out:
        kfree(out_buf);
        return rc;
}

static void
smb2_close_cached_fid(struct kref *ref)
{
        struct cached_fid *cfid = container_of(ref, struct cached_fid,
                                               refcount);

        if (cfid->is_valid) {
                cifs_dbg(FYI, "clear cached root file handle\n");
                SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,
                           cfid->fid->volatile_fid);
                cfid->is_valid = false;
                cfid->file_all_info_is_valid = false;
        }
}

void close_shroot(struct cached_fid *cfid)
{
        mutex_lock(&cfid->fid_mutex);
        kref_put(&cfid->refcount, smb2_close_cached_fid);
        mutex_unlock(&cfid->fid_mutex);
}

void
smb2_cached_lease_break(struct work_struct *work)
{
        struct cached_fid *cfid = container_of(work,
                                struct cached_fid, lease_break);

        close_shroot(cfid);
}

/*
 * Open the directory at the root of a share
 */
int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
{
        struct cifs_ses *ses = tcon->ses;
        struct TCP_Server_Info *server = ses->server;
        struct cifs_open_parms oparms;
        struct smb2_create_rsp *o_rsp = NULL;
        struct smb2_query_info_rsp *qi_rsp = NULL;
        int resp_buftype[2];
        struct smb_rqst rqst[2];
        struct kvec rsp_iov[2];
        struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
        struct kvec qi_iov[1];
        int rc, flags = 0;
        __le16 utf16_path = 0; /* Null - since an open of top of share */
        u8 oplock = SMB2_OPLOCK_LEVEL_II;

        mutex_lock(&tcon->crfid.fid_mutex);
        if (tcon->crfid.is_valid) {
                cifs_dbg(FYI, "found a cached root file handle\n");
                memcpy(pfid, tcon->crfid.fid, sizeof(struct cifs_fid));
                kref_get(&tcon->crfid.refcount);
                mutex_unlock(&tcon->crfid.fid_mutex);
                return 0;
        }

        if (smb3_encryption_required(tcon))
                flags |= CIFS_TRANSFORM_REQ;

        memset(rqst, 0, sizeof(rqst));
        resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
        memset(rsp_iov, 0, sizeof(rsp_iov));

        /* Open */
        memset(&open_iov, 0, sizeof(open_iov));
        rqst[0].rq_iov = open_iov;
        rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;

        oparms.tcon = tcon;
        oparms.create_options = 0;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        oparms.fid = pfid;
        oparms.reconnect = false;

        rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, &utf16_path);
        if (rc)
                goto oshr_exit;
        smb2_set_next_command(tcon, &rqst[0]);

        memset(&qi_iov, 0, sizeof(qi_iov));
        rqst[1].rq_iov = qi_iov;
        rqst[1].rq_nvec = 1;

        rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID,
                                  COMPOUND_FID, FILE_ALL_INFORMATION,
                                  SMB2_O_INFO_FILE, 0,
                                  sizeof(struct smb2_file_all_info) +
                                  PATH_MAX * 2, 0, NULL);
        if (rc)
                goto oshr_exit;

        smb2_set_related(&rqst[1]);

        rc = compound_send_recv(xid, ses, flags, 2, rqst,
                                resp_buftype, rsp_iov);
        if (rc)
                goto oshr_exit;

        o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
        oparms.fid->persistent_fid = o_rsp->PersistentFileId;
        oparms.fid->volatile_fid = o_rsp->VolatileFileId;
#ifdef CONFIG_CIFS_DEBUG2
        oparms.fid->mid = le64_to_cpu(o_rsp->sync_hdr.MessageId);
#endif /* CIFS_DEBUG2 */

        memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
        tcon->crfid.tcon = tcon;
        tcon->crfid.is_valid = true;
        kref_init(&tcon->crfid.refcount);

        if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) {
                kref_get(&tcon->crfid.refcount);
                oplock = smb2_parse_lease_state(server, o_rsp,
                                                &oparms.fid->epoch,
                                                oparms.fid->lease_key);
        } else
                goto oshr_exit;

        qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
        if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
                goto oshr_exit;
        if (!smb2_validate_and_copy_iov(
                                le16_to_cpu(qi_rsp->OutputBufferOffset),
                                sizeof(struct smb2_file_all_info),
                                &rsp_iov[1], sizeof(struct smb2_file_all_info),
                                (char *)&tcon->crfid.file_all_info))
                tcon->crfid.file_all_info_is_valid = 1;

 oshr_exit:
        mutex_unlock(&tcon->crfid.fid_mutex);
        SMB2_open_free(&rqst[0]);
        SMB2_query_info_free(&rqst[1]);
        free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
        free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
        return rc;
}

static void
smb3_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
{
        int rc;
        __le16 srch_path = 0; /* Null - open root of share */
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
        bool no_cached_open = tcon->nohandlecache;

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        if (no_cached_open)
                rc = SMB2_open(xid, &oparms, &srch_path, &oplock, NULL, NULL,
                               NULL);
        else
                rc = open_shroot(xid, tcon, &fid);

        if (rc)
                return;

        SMB3_request_interfaces(xid, tcon);

        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_ATTRIBUTE_INFORMATION);
        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_DEVICE_INFORMATION);
        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_VOLUME_INFORMATION);
        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_SECTOR_SIZE_INFORMATION); /* SMB3 specific */
        if (no_cached_open)
                SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        else
                close_shroot(&tcon->crfid);

        return;
}

static void
smb2_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
{
        int rc;
        __le16 srch_path = 0; /* Null - open root of share */
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, &srch_path, &oplock, NULL, NULL, NULL);
        if (rc)
                return;

        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_ATTRIBUTE_INFORMATION);
        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
                        FS_DEVICE_INFORMATION);
        SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        return;
}

static int
smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
                        struct cifs_sb_info *cifs_sb, const char *full_path)
{
        int rc;
        __le16 *utf16_path;
        __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;

        if ((*full_path == 0) && tcon->crfid.is_valid)
                return 0;

        utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
        if (!utf16_path)
                return -ENOMEM;

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL);
        if (rc) {
                kfree(utf16_path);
                return rc;
        }

        rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        kfree(utf16_path);
        return rc;
}

static int
smb2_get_srv_inum(const unsigned int xid, struct cifs_tcon *tcon,
                  struct cifs_sb_info *cifs_sb, const char *full_path,
                  u64 *uniqueid, FILE_ALL_INFO *data)
{
        *uniqueid = le64_to_cpu(data->IndexNumber);
        return 0;
}

static int
smb2_query_file_info(const unsigned int xid, struct cifs_tcon *tcon,
                     struct cifs_fid *fid, FILE_ALL_INFO *data)
{
        int rc;
        struct smb2_file_all_info *smb2_data;

        smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
                            GFP_KERNEL);
        if (smb2_data == NULL)
                return -ENOMEM;

        rc = SMB2_query_info(xid, tcon, fid->persistent_fid, fid->volatile_fid,
                             smb2_data);
        if (!rc)
                move_smb2_info_to_cifs(data, smb2_data);
        kfree(smb2_data);
        return rc;
}

#ifdef CONFIG_CIFS_XATTR
static ssize_t
move_smb2_ea_to_cifs(char *dst, size_t dst_size,
                     struct smb2_file_full_ea_info *src, size_t src_size,
                     const unsigned char *ea_name)
{
        int rc = 0;
        unsigned int ea_name_len = ea_name ? strlen(ea_name) : 0;
        char *name, *value;
        size_t buf_size = dst_size;
        size_t name_len, value_len, user_name_len;

        while (src_size > 0) {
                name = &src->ea_data[0];
                name_len = (size_t)src->ea_name_length;
                value = &src->ea_data[src->ea_name_length + 1];
                value_len = (size_t)le16_to_cpu(src->ea_value_length);

                if (name_len == 0) {
                        break;
                }

                if (src_size < 8 + name_len + 1 + value_len) {
                        cifs_dbg(FYI, "EA entry goes beyond length of list\n");
                        rc = -EIO;
                        goto out;
                }

                if (ea_name) {
                        if (ea_name_len == name_len &&
                            memcmp(ea_name, name, name_len) == 0) {
                                rc = value_len;
                                if (dst_size == 0)
                                        goto out;
                                if (dst_size < value_len) {
                                        rc = -ERANGE;
                                        goto out;
                                }
                                memcpy(dst, value, value_len);
                                goto out;
                        }
                } else {
                        /* 'user.' plus a terminating null */
                        user_name_len = 5 + 1 + name_len;

                        if (buf_size == 0) {
                                /* skip copy - calc size only */
                                rc += user_name_len;
                        } else if (dst_size >= user_name_len) {
                                dst_size -= user_name_len;
                                memcpy(dst, "user.", 5);
                                dst += 5;
                                memcpy(dst, src->ea_data, name_len);
                                dst += name_len;
                                *dst = 0;
                                ++dst;
                                rc += user_name_len;
                        } else {
                                /* stop before overrun buffer */
                                rc = -ERANGE;
                                break;
                        }
                }

                if (!src->next_entry_offset)
                        break;

                if (src_size < le32_to_cpu(src->next_entry_offset)) {
                        /* stop before overrun buffer */
                        rc = -ERANGE;
                        break;
                }
                src_size -= le32_to_cpu(src->next_entry_offset);
                src = (void *)((char *)src +
                               le32_to_cpu(src->next_entry_offset));
        }

        /* didn't find the named attribute */
        if (ea_name)
                rc = -ENODATA;

out:
        return (ssize_t)rc;
}

static ssize_t
smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon,
               const unsigned char *path, const unsigned char *ea_name,
               char *ea_data, size_t buf_size,
               struct cifs_sb_info *cifs_sb)
{
        int rc;
        __le16 *utf16_path;
        struct kvec rsp_iov = {NULL, 0};
        int buftype = CIFS_NO_BUFFER;
        struct smb2_query_info_rsp *rsp;
        struct smb2_file_full_ea_info *info = NULL;

        utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
        if (!utf16_path)
                return -ENOMEM;

        rc = smb2_query_info_compound(xid, tcon, utf16_path,
                                      FILE_READ_EA,
                                      FILE_FULL_EA_INFORMATION,
                                      SMB2_O_INFO_FILE,
                                      CIFSMaxBufSize -
                                      MAX_SMB2_CREATE_RESPONSE_SIZE -
                                      MAX_SMB2_CLOSE_RESPONSE_SIZE,
                                      &rsp_iov, &buftype, cifs_sb);

        if (rc) {
                /*
                 * If ea_name is NULL (listxattr) and there are no EAs,
                 * return 0 as it's not an error. Otherwise, the specified
                 * ea_name was not found.
                 */
                if (!ea_name && rc == -ENODATA)
                        rc = 0;
                goto qeas_exit;
        }

        rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
        rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
                               le32_to_cpu(rsp->OutputBufferLength),
                               &rsp_iov,
                               sizeof(struct smb2_file_full_ea_info));
        if (rc)
                goto qeas_exit;

        info = (struct smb2_file_full_ea_info *)(
                        le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
        rc = move_smb2_ea_to_cifs(ea_data, buf_size, info,
                        le32_to_cpu(rsp->OutputBufferLength), ea_name);

 qeas_exit:
        kfree(utf16_path);
        free_rsp_buf(buftype, rsp_iov.iov_base);
        return rc;
}


static int
smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon,
            const char *path, const char *ea_name, const void *ea_value,
            const __u16 ea_value_len, const struct nls_table *nls_codepage,
            struct cifs_sb_info *cifs_sb)
{
        struct cifs_ses *ses = tcon->ses;
        __le16 *utf16_path = NULL;
        int ea_name_len = strlen(ea_name);
        int flags = 0;
        int len;
        struct smb_rqst rqst[3];
        int resp_buftype[3];
        struct kvec rsp_iov[3];
        struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
        struct cifs_open_parms oparms;
        __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_fid fid;
        struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];
        unsigned int size[1];
        void *data[1];
        struct smb2_file_full_ea_info *ea = NULL;
        struct kvec close_iov[1];
        int rc;

        if (smb3_encryption_required(tcon))
                flags |= CIFS_TRANSFORM_REQ;

        if (ea_name_len > 255)
                return -EINVAL;

        utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
        if (!utf16_path)
                return -ENOMEM;

        memset(rqst, 0, sizeof(rqst));
        resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
        memset(rsp_iov, 0, sizeof(rsp_iov));

        if (ses->server->ops->query_all_EAs) {
                if (!ea_value) {
                        rc = ses->server->ops->query_all_EAs(xid, tcon, path,
                                                             ea_name, NULL, 0,
                                                             cifs_sb);
                        if (rc == -ENODATA)
                                goto sea_exit;
                }
        }

        /* Open */
        memset(&open_iov, 0, sizeof(open_iov));
        rqst[0].rq_iov = open_iov;
        rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;

        memset(&oparms, 0, sizeof(oparms));
        oparms.tcon = tcon;
        oparms.desired_access = FILE_WRITE_EA;
        oparms.disposition = FILE_OPEN;
        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, utf16_path);
        if (rc)
                goto sea_exit;
        smb2_set_next_command(tcon, &rqst[0]);


        /* Set Info */
        memset(&si_iov, 0, sizeof(si_iov));
        rqst[1].rq_iov = si_iov;
        rqst[1].rq_nvec = 1;

        len = sizeof(ea) + ea_name_len + ea_value_len + 1;
        ea = kzalloc(len, GFP_KERNEL);
        if (ea == NULL) {
                rc = -ENOMEM;
                goto sea_exit;
        }

        ea->ea_name_length = ea_name_len;
        ea->ea_value_length = cpu_to_le16(ea_value_len);
        memcpy(ea->ea_data, ea_name, ea_name_len + 1);
        memcpy(ea->ea_data + ea_name_len + 1, ea_value, ea_value_len);

        size[0] = len;
        data[0] = ea;

        rc = SMB2_set_info_init(tcon, &rqst[1], COMPOUND_FID,
                                COMPOUND_FID, current->tgid,
                                FILE_FULL_EA_INFORMATION,
                                SMB2_O_INFO_FILE, 0, data, size);
        smb2_set_next_command(tcon, &rqst[1]);
        smb2_set_related(&rqst[1]);


        /* Close */
        memset(&close_iov, 0, sizeof(close_iov));
        rqst[2].rq_iov = close_iov;
        rqst[2].rq_nvec = 1;
        rc = SMB2_close_init(tcon, &rqst[2], COMPOUND_FID, COMPOUND_FID);
        smb2_set_related(&rqst[2]);

        rc = compound_send_recv(xid, ses, flags, 3, rqst,
                                resp_buftype, rsp_iov);

 sea_exit:
        kfree(ea);
        kfree(utf16_path);
        SMB2_open_free(&rqst[0]);
        SMB2_set_info_free(&rqst[1]);
        SMB2_close_free(&rqst[2]);
        free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
        free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
        free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);
        return rc;
}
#endif

static bool
smb2_can_echo(struct TCP_Server_Info *server)
{
        return server->echoes;
}

static void
smb2_clear_stats(struct cifs_tcon *tcon)
{
        int i;
        for (i = 0; i < NUMBER_OF_SMB2_COMMANDS; i++) {
                atomic_set(&tcon->stats.smb2_stats.smb2_com_sent[i], 0);
                atomic_set(&tcon->stats.smb2_stats.smb2_com_failed[i], 0);
        }
}

static void
smb2_dump_share_caps(struct seq_file *m, struct cifs_tcon *tcon)
{
        seq_puts(m, "\n\tShare Capabilities:");
        if (tcon->capabilities & SMB2_SHARE_CAP_DFS)
                seq_puts(m, " DFS,");
        if (tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
                seq_puts(m, " CONTINUOUS AVAILABILITY,");
        if (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT)
                seq_puts(m, " SCALEOUT,");
        if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER)
                seq_puts(m, " CLUSTER,");
        if (tcon->capabilities & SMB2_SHARE_CAP_ASYMMETRIC)
                seq_puts(m, " ASYMMETRIC,");
        if (tcon->capabilities == 0)
                seq_puts(m, " None");
        if (tcon->ss_flags & SSINFO_FLAGS_ALIGNED_DEVICE)
                seq_puts(m, " Aligned,");
        if (tcon->ss_flags & SSINFO_FLAGS_PARTITION_ALIGNED_ON_DEVICE)
                seq_puts(m, " Partition Aligned,");
        if (tcon->ss_flags & SSINFO_FLAGS_NO_SEEK_PENALTY)
                seq_puts(m, " SSD,");
        if (tcon->ss_flags & SSINFO_FLAGS_TRIM_ENABLED)
                seq_puts(m, " TRIM-support,");

        seq_printf(m, "\tShare Flags: 0x%x", tcon->share_flags);
        seq_printf(m, "\n\ttid: 0x%x", tcon->tid);
        if (tcon->perf_sector_size)
                seq_printf(m, "\tOptimal sector size: 0x%x",
                           tcon->perf_sector_size);
        seq_printf(m, "\tMaximal Access: 0x%x", tcon->maximal_access);
}

static void
smb2_print_stats(struct seq_file *m, struct cifs_tcon *tcon)
{
        atomic_t *sent = tcon->stats.smb2_stats.smb2_com_sent;
        atomic_t *failed = tcon->stats.smb2_stats.smb2_com_failed;

        /*
         *  Can't display SMB2_NEGOTIATE, SESSION_SETUP, LOGOFF, CANCEL and ECHO
         *  totals (requests sent) since those SMBs are per-session not per tcon
         */
        seq_printf(m, "\nBytes read: %llu  Bytes written: %llu",
                   (long long)(tcon->bytes_read),
                   (long long)(tcon->bytes_written));
        seq_printf(m, "\nOpen files: %d total (local), %d open on server",
                   atomic_read(&tcon->num_local_opens),
                   atomic_read(&tcon->num_remote_opens));
        seq_printf(m, "\nTreeConnects: %d total %d failed",
                   atomic_read(&sent[SMB2_TREE_CONNECT_HE]),
                   atomic_read(&failed[SMB2_TREE_CONNECT_HE]));
        seq_printf(m, "\nTreeDisconnects: %d total %d failed",
                   atomic_read(&sent[SMB2_TREE_DISCONNECT_HE]),
                   atomic_read(&failed[SMB2_TREE_DISCONNECT_HE]));
        seq_printf(m, "\nCreates: %d total %d failed",
                   atomic_read(&sent[SMB2_CREATE_HE]),
                   atomic_read(&failed[SMB2_CREATE_HE]));
        seq_printf(m, "\nCloses: %d total %d failed",
                   atomic_read(&sent[SMB2_CLOSE_HE]),
                   atomic_read(&failed[SMB2_CLOSE_HE]));
        seq_printf(m, "\nFlushes: %d total %d failed",
                   atomic_read(&sent[SMB2_FLUSH_HE]),
                   atomic_read(&failed[SMB2_FLUSH_HE]));
        seq_printf(m, "\nReads: %d total %d failed",
                   atomic_read(&sent[SMB2_READ_HE]),
                   atomic_read(&failed[SMB2_READ_HE]));
        seq_printf(m, "\nWrites: %d total %d failed",
                   atomic_read(&sent[SMB2_WRITE_HE]),
                   atomic_read(&failed[SMB2_WRITE_HE]));
        seq_printf(m, "\nLocks: %d total %d failed",
                   atomic_read(&sent[SMB2_LOCK_HE]),
                   atomic_read(&failed[SMB2_LOCK_HE]));
        seq_printf(m, "\nIOCTLs: %d total %d failed",
                   atomic_read(&sent[SMB2_IOCTL_HE]),
                   atomic_read(&failed[SMB2_IOCTL_HE]));
        seq_printf(m, "\nQueryDirectories: %d total %d failed",
                   atomic_read(&sent[SMB2_QUERY_DIRECTORY_HE]),
                   atomic_read(&failed[SMB2_QUERY_DIRECTORY_HE]));
        seq_printf(m, "\nChangeNotifies: %d total %d failed",
                   atomic_read(&sent[SMB2_CHANGE_NOTIFY_HE]),
                   atomic_read(&failed[SMB2_CHANGE_NOTIFY_HE]));
        seq_printf(m, "\nQueryInfos: %d total %d failed",
                   atomic_read(&sent[SMB2_QUERY_INFO_HE]),
                   atomic_read(&failed[SMB2_QUERY_INFO_HE]));
        seq_printf(m, "\nSetInfos: %d total %d failed",
                   atomic_read(&sent[SMB2_SET_INFO_HE]),
                   atomic_read(&failed[SMB2_SET_INFO_HE]));
        seq_printf(m, "\nOplockBreaks: %d sent %d failed",
                   atomic_read(&sent[SMB2_OPLOCK_BREAK_HE]),
                   atomic_read(&failed[SMB2_OPLOCK_BREAK_HE]));
}

static void
smb2_set_fid(struct cifsFileInfo *cfile, struct cifs_fid *fid, __u32 oplock)
{
        struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
        struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;

        cfile->fid.persistent_fid = fid->persistent_fid;
        cfile->fid.volatile_fid = fid->volatile_fid;
#ifdef CONFIG_CIFS_DEBUG2
        cfile->fid.mid = fid->mid;
#endif /* CIFS_DEBUG2 */
        server->ops->set_oplock_level(cinode, oplock, fid->epoch,
                                      &fid->purge_cache);
        cinode->can_cache_brlcks = CIFS_CACHE_WRITE(cinode);
        memcpy(cfile->fid.create_guid, fid->create_guid, 16);
}

static void
smb2_close_file(const unsigned int xid, struct cifs_tcon *tcon,
                struct cifs_fid *fid)
{
        SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
}

static int
SMB2_request_res_key(const unsigned int xid, struct cifs_tcon *tcon,
                     u64 persistent_fid, u64 volatile_fid,
                     struct copychunk_ioctl *pcchunk)
{
        int rc;
        unsigned int ret_data_len;
        struct resume_key_req *res_key;

        rc = SMB2_ioctl(xid, tcon, persistent_fid, volatile_fid,
                        FSCTL_SRV_REQUEST_RESUME_KEY, true /* is_fsctl */,
                        NULL, 0 /* no input */, CIFSMaxBufSize,
                        (char **)&res_key, &ret_data_len);

        if (rc) {
                cifs_dbg(VFS, "refcpy ioctl error %d getting resume key\n", rc);
                goto req_res_key_exit;
        }
        if (ret_data_len < sizeof(struct resume_key_req)) {
                cifs_dbg(VFS, "Invalid refcopy resume key length\n");
                rc = -EINVAL;
                goto req_res_key_exit;
        }
        memcpy(pcchunk->SourceKey, res_key->ResumeKey, COPY_CHUNK_RES_KEY_SIZE);

req_res_key_exit:
        kfree(res_key);
        return rc;
}

static int
smb2_ioctl_query_info(const unsigned int xid,
                      struct cifs_tcon *tcon,
                      __le16 *path, int is_dir,
                      unsigned long p)
{
        struct cifs_ses *ses = tcon->ses;
        char __user *arg = (char __user *)p;
        struct smb_query_info qi;
        struct smb_query_info __user *pqi;
        int rc = 0;
        int flags = 0;
        struct smb2_query_info_rsp *qi_rsp = NULL;
        struct smb2_ioctl_rsp *io_rsp = NULL;
        void *buffer = NULL;
        struct smb_rqst rqst[3];
        int resp_buftype[3];
        struct kvec rsp_iov[3];
        struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
        struct cifs_open_parms oparms;
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_fid fid;
        struct kvec qi_iov[1];
        struct kvec io_iov[SMB2_IOCTL_IOV_SIZE];
        struct kvec close_iov[1];

        memset(rqst, 0, sizeof(rqst));
        resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
        memset(rsp_iov, 0, sizeof(rsp_iov));

        if (copy_from_user(&qi, arg, sizeof(struct smb_query_info)))
                return -EFAULT;

        if (qi.output_buffer_length > 1024)
                return -EINVAL;

        if (!ses || !(ses->server))
                return -EIO;

        if (smb3_encryption_required(tcon))
                flags |= CIFS_TRANSFORM_REQ;

        buffer = kmalloc(qi.output_buffer_length, GFP_KERNEL);
        if (buffer == NULL)
                return -ENOMEM;

        if (copy_from_user(buffer, arg + sizeof(struct smb_query_info),
                           qi.output_buffer_length)) {
                rc = -EFAULT;
                goto iqinf_exit;
        }

        /* Open */
        memset(&open_iov, 0, sizeof(open_iov));
        rqst[0].rq_iov = open_iov;
        rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;

        memset(&oparms, 0, sizeof(oparms));
        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES | READ_CONTROL;
        oparms.disposition = FILE_OPEN;
        if (is_dir)
                oparms.create_options = CREATE_NOT_FILE;
        else
                oparms.create_options = CREATE_NOT_DIR;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, path);
        if (rc)
                goto iqinf_exit;
        smb2_set_next_command(tcon, &rqst[0]);

        /* Query */
        if (qi.flags & PASSTHRU_FSCTL) {
                /* Can eventually relax perm check since server enforces too */
                if (!capable(CAP_SYS_ADMIN))
                        rc = -EPERM;
                else  {
                        memset(&io_iov, 0, sizeof(io_iov));
                        rqst[1].rq_iov = io_iov;
                        rqst[1].rq_nvec = SMB2_IOCTL_IOV_SIZE;

                        rc = SMB2_ioctl_init(tcon, &rqst[1],
                                             COMPOUND_FID, COMPOUND_FID,
                                             qi.info_type, true, NULL,
                                             0, CIFSMaxBufSize);
                }
        } else if (qi.flags == PASSTHRU_QUERY_INFO) {
                memset(&qi_iov, 0, sizeof(qi_iov));
                rqst[1].rq_iov = qi_iov;
                rqst[1].rq_nvec = 1;

                rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID,
                                  COMPOUND_FID, qi.file_info_class,
                                  qi.info_type, qi.additional_information,
                                  qi.input_buffer_length,
                                  qi.output_buffer_length, buffer);
        } else { /* unknown flags */
                cifs_dbg(VFS, "invalid passthru query flags: 0x%x\n", qi.flags);
                rc = -EINVAL;
        }

        if (rc)
                goto iqinf_exit;
        smb2_set_next_command(tcon, &rqst[1]);
        smb2_set_related(&rqst[1]);

        /* Close */
        memset(&close_iov, 0, sizeof(close_iov));
        rqst[2].rq_iov = close_iov;
        rqst[2].rq_nvec = 1;

        rc = SMB2_close_init(tcon, &rqst[2], COMPOUND_FID, COMPOUND_FID);
        if (rc)
                goto iqinf_exit;
        smb2_set_related(&rqst[2]);

        rc = compound_send_recv(xid, ses, flags, 3, rqst,
                                resp_buftype, rsp_iov);
        if (rc)
                goto iqinf_exit;
        if (qi.flags & PASSTHRU_FSCTL) {
                pqi = (struct smb_query_info __user *)arg;
                io_rsp = (struct smb2_ioctl_rsp *)rsp_iov[1].iov_base;
                if (le32_to_cpu(io_rsp->OutputCount) < qi.input_buffer_length)
                        qi.input_buffer_length = le32_to_cpu(io_rsp->OutputCount);
                if (copy_to_user(&pqi->input_buffer_length, &qi.input_buffer_length,
                                 sizeof(qi.input_buffer_length))) {
                        rc = -EFAULT;
                        goto iqinf_exit;
                }
                if (copy_to_user(pqi + 1, &io_rsp[1], qi.input_buffer_length)) {
                        rc = -EFAULT;
                        goto iqinf_exit;
                }
        } else {
                pqi = (struct smb_query_info __user *)arg;
                qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
                if (le32_to_cpu(qi_rsp->OutputBufferLength) < qi.input_buffer_length)
                        qi.input_buffer_length = le32_to_cpu(qi_rsp->OutputBufferLength);
                if (copy_to_user(&pqi->input_buffer_length, &qi.input_buffer_length,
                                 sizeof(qi.input_buffer_length))) {
                        rc = -EFAULT;
                        goto iqinf_exit;
                }
                if (copy_to_user(pqi + 1, qi_rsp->Buffer, qi.input_buffer_length)) {
                        rc = -EFAULT;
                        goto iqinf_exit;
                }
        }

 iqinf_exit:
        kfree(buffer);
        SMB2_open_free(&rqst[0]);
        if (qi.flags & PASSTHRU_FSCTL)
                SMB2_ioctl_free(&rqst[1]);
        else
                SMB2_query_info_free(&rqst[1]);

        SMB2_close_free(&rqst[2]);
        free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
        free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
        free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);
        return rc;
}

static ssize_t
smb2_copychunk_range(const unsigned int xid,
                        struct cifsFileInfo *srcfile,
                        struct cifsFileInfo *trgtfile, u64 src_off,
                        u64 len, u64 dest_off)
{
        int rc;
        unsigned int ret_data_len;
        struct copychunk_ioctl *pcchunk;
        struct copychunk_ioctl_rsp *retbuf = NULL;
        struct cifs_tcon *tcon;
        int chunks_copied = 0;
        bool chunk_sizes_updated = false;
        ssize_t bytes_written, total_bytes_written = 0;

        pcchunk = kmalloc(sizeof(struct copychunk_ioctl), GFP_KERNEL);

        if (pcchunk == NULL)
                return -ENOMEM;

        cifs_dbg(FYI, "in smb2_copychunk_range - about to call request res key\n");
        /* Request a key from the server to identify the source of the copy */
        rc = SMB2_request_res_key(xid, tlink_tcon(srcfile->tlink),
                                srcfile->fid.persistent_fid,
                                srcfile->fid.volatile_fid, pcchunk);

        /* Note: request_res_key sets res_key null only if rc !=0 */
        if (rc)
                goto cchunk_out;

        /* For now array only one chunk long, will make more flexible later */
        pcchunk->ChunkCount = cpu_to_le32(1);
        pcchunk->Reserved = 0;
        pcchunk->Reserved2 = 0;

        tcon = tlink_tcon(trgtfile->tlink);

        while (len > 0) {
                pcchunk->SourceOffset = cpu_to_le64(src_off);
                pcchunk->TargetOffset = cpu_to_le64(dest_off);
                pcchunk->Length =
                        cpu_to_le32(min_t(u32, len, tcon->max_bytes_chunk));

                /* Request server copy to target from src identified by key */
                rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
                        trgtfile->fid.volatile_fid, FSCTL_SRV_COPYCHUNK_WRITE,
                        true /* is_fsctl */, (char *)pcchunk,
                        sizeof(struct copychunk_ioctl), CIFSMaxBufSize,
                        (char **)&retbuf, &ret_data_len);
                if (rc == 0) {
                        if (ret_data_len !=
                                        sizeof(struct copychunk_ioctl_rsp)) {
                                cifs_dbg(VFS, "invalid cchunk response size\n");
                                rc = -EIO;
                                goto cchunk_out;
                        }
                        if (retbuf->TotalBytesWritten == 0) {
                                cifs_dbg(FYI, "no bytes copied\n");
                                rc = -EIO;
                                goto cchunk_out;
                        }
                        /*
                         * Check if server claimed to write more than we asked
                         */
                        if (le32_to_cpu(retbuf->TotalBytesWritten) >
                            le32_to_cpu(pcchunk->Length)) {
                                cifs_dbg(VFS, "invalid copy chunk response\n");
                                rc = -EIO;
                                goto cchunk_out;
                        }
                        if (le32_to_cpu(retbuf->ChunksWritten) != 1) {
                                cifs_dbg(VFS, "invalid num chunks written\n");
                                rc = -EIO;
                                goto cchunk_out;
                        }
                        chunks_copied++;

                        bytes_written = le32_to_cpu(retbuf->TotalBytesWritten);
                        src_off += bytes_written;
                        dest_off += bytes_written;
                        len -= bytes_written;
                        total_bytes_written += bytes_written;

                        cifs_dbg(FYI, "Chunks %d PartialChunk %d Total %zu\n",
                                le32_to_cpu(retbuf->ChunksWritten),
                                le32_to_cpu(retbuf->ChunkBytesWritten),
                                bytes_written);
                } else if (rc == -EINVAL) {
                        if (ret_data_len != sizeof(struct copychunk_ioctl_rsp))
                                goto cchunk_out;

                        cifs_dbg(FYI, "MaxChunks %d BytesChunk %d MaxCopy %d\n",
                                le32_to_cpu(retbuf->ChunksWritten),
                                le32_to_cpu(retbuf->ChunkBytesWritten),
                                le32_to_cpu(retbuf->TotalBytesWritten));

                        /*
                         * Check if this is the first request using these sizes,
                         * (ie check if copy succeed once with original sizes
                         * and check if the server gave us different sizes after
                         * we already updated max sizes on previous request).
                         * if not then why is the server returning an error now
                         */
                        if ((chunks_copied != 0) || chunk_sizes_updated)
                                goto cchunk_out;

                        /* Check that server is not asking us to grow size */
                        if (le32_to_cpu(retbuf->ChunkBytesWritten) <
                                        tcon->max_bytes_chunk)
                                tcon->max_bytes_chunk =
                                        le32_to_cpu(retbuf->ChunkBytesWritten);
                        else
                                goto cchunk_out; /* server gave us bogus size */

                        /* No need to change MaxChunks since already set to 1 */
                        chunk_sizes_updated = true;
                } else
                        goto cchunk_out;
        }

cchunk_out:
        kfree(pcchunk);
        kfree(retbuf);
        if (rc)
                return rc;
        else
                return total_bytes_written;
}

static int
smb2_flush_file(const unsigned int xid, struct cifs_tcon *tcon,
                struct cifs_fid *fid)
{
        return SMB2_flush(xid, tcon, fid->persistent_fid, fid->volatile_fid);
}

static unsigned int
smb2_read_data_offset(char *buf)
{
        struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;
        return rsp->DataOffset;
}

static unsigned int
smb2_read_data_length(char *buf, bool in_remaining)
{
        struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;

        if (in_remaining)
                return le32_to_cpu(rsp->DataRemaining);

        return le32_to_cpu(rsp->DataLength);
}


static int
smb2_sync_read(const unsigned int xid, struct cifs_fid *pfid,
               struct cifs_io_parms *parms, unsigned int *bytes_read,
               char **buf, int *buf_type)
{
        parms->persistent_fid = pfid->persistent_fid;
        parms->volatile_fid = pfid->volatile_fid;
        return SMB2_read(xid, parms, bytes_read, buf, buf_type);
}

static int
smb2_sync_write(const unsigned int xid, struct cifs_fid *pfid,
                struct cifs_io_parms *parms, unsigned int *written,
                struct kvec *iov, unsigned long nr_segs)
{

        parms->persistent_fid = pfid->persistent_fid;
        parms->volatile_fid = pfid->volatile_fid;
        return SMB2_write(xid, parms, written, iov, nr_segs);
}

/* Set or clear the SPARSE_FILE attribute based on value passed in setsparse */
static bool smb2_set_sparse(const unsigned int xid, struct cifs_tcon *tcon,
                struct cifsFileInfo *cfile, struct inode *inode, __u8 setsparse)
{
        struct cifsInodeInfo *cifsi;
        int rc;

        cifsi = CIFS_I(inode);

        /* if file already sparse don't bother setting sparse again */
        if ((cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) && setsparse)
                return true; /* already sparse */

        if (!(cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) && !setsparse)
                return true; /* already not sparse */

        /*
         * Can't check for sparse support on share the usual way via the
         * FS attribute info (FILE_SUPPORTS_SPARSE_FILES) on the share
         * since Samba server doesn't set the flag on the share, yet
         * supports the set sparse FSCTL and returns sparse correctly
         * in the file attributes. If we fail setting sparse though we
         * mark that server does not support sparse files for this share
         * to avoid repeatedly sending the unsupported fsctl to server
         * if the file is repeatedly extended.
         */
        if (tcon->broken_sparse_sup)
                return false;

        rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
                        cfile->fid.volatile_fid, FSCTL_SET_SPARSE,
                        true /* is_fctl */,
                        &setsparse, 1, CIFSMaxBufSize, NULL, NULL);
        if (rc) {
                tcon->broken_sparse_sup = true;
                cifs_dbg(FYI, "set sparse rc = %d\n", rc);
                return false;
        }

        if (setsparse)
                cifsi->cifsAttrs |= FILE_ATTRIBUTE_SPARSE_FILE;
        else
                cifsi->cifsAttrs &= (~FILE_ATTRIBUTE_SPARSE_FILE);

        return true;
}

static int
smb2_set_file_size(const unsigned int xid, struct cifs_tcon *tcon,
                   struct cifsFileInfo *cfile, __u64 size, bool set_alloc)
{
        __le64 eof = cpu_to_le64(size);
        struct inode *inode;

        /*
         * If extending file more than one page make sparse. Many Linux fs
         * make files sparse by default when extending via ftruncate
         */
        inode = d_inode(cfile->dentry);

        if (!set_alloc && (size > inode->i_size + 8192)) {
                __u8 set_sparse = 1;

                /* whether set sparse succeeds or not, extend the file */
                smb2_set_sparse(xid, tcon, cfile, inode, set_sparse);
        }

        return SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
                            cfile->fid.volatile_fid, cfile->pid, &eof);
}

static int
smb2_duplicate_extents(const unsigned int xid,
                        struct cifsFileInfo *srcfile,
                        struct cifsFileInfo *trgtfile, u64 src_off,
                        u64 len, u64 dest_off)
{
        int rc;
        unsigned int ret_data_len;
        struct duplicate_extents_to_file dup_ext_buf;
        struct cifs_tcon *tcon = tlink_tcon(trgtfile->tlink);

        /* server fileays advertise duplicate extent support with this flag */
        if ((le32_to_cpu(tcon->fsAttrInfo.Attributes) &
             FILE_SUPPORTS_BLOCK_REFCOUNTING) == 0)
                return -EOPNOTSUPP;

        dup_ext_buf.VolatileFileHandle = srcfile->fid.volatile_fid;
        dup_ext_buf.PersistentFileHandle = srcfile->fid.persistent_fid;
        dup_ext_buf.SourceFileOffset = cpu_to_le64(src_off);
        dup_ext_buf.TargetFileOffset = cpu_to_le64(dest_off);
        dup_ext_buf.ByteCount = cpu_to_le64(len);
        cifs_dbg(FYI, "duplicate extents: src off %lld dst off %lld len %lld",
                src_off, dest_off, len);

        rc = smb2_set_file_size(xid, tcon, trgtfile, dest_off + len, false);
        if (rc)
                goto duplicate_extents_out;

        rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
                        trgtfile->fid.volatile_fid,
                        FSCTL_DUPLICATE_EXTENTS_TO_FILE,
                        true /* is_fsctl */,
                        (char *)&dup_ext_buf,
                        sizeof(struct duplicate_extents_to_file),
                        CIFSMaxBufSize, NULL,
                        &ret_data_len);

        if (ret_data_len > 0)
                cifs_dbg(FYI, "non-zero response length in duplicate extents");

duplicate_extents_out:
        return rc;
}

static int
smb2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
                   struct cifsFileInfo *cfile)
{
        return SMB2_set_compression(xid, tcon, cfile->fid.persistent_fid,
                            cfile->fid.volatile_fid);
}

static int
smb3_set_integrity(const unsigned int xid, struct cifs_tcon *tcon,
                   struct cifsFileInfo *cfile)
{
        struct fsctl_set_integrity_information_req integr_info;
        unsigned int ret_data_len;

        integr_info.ChecksumAlgorithm = cpu_to_le16(CHECKSUM_TYPE_UNCHANGED);
        integr_info.Flags = 0;
        integr_info.Reserved = 0;

        return SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
                        cfile->fid.volatile_fid,
                        FSCTL_SET_INTEGRITY_INFORMATION,
                        true /* is_fsctl */,
                        (char *)&integr_info,
                        sizeof(struct fsctl_set_integrity_information_req),
                        CIFSMaxBufSize, NULL,
                        &ret_data_len);

}

/* GMT Token is @GMT-YYYY.MM.DD-HH.MM.SS Unicode which is 48 bytes + null */
#define GMT_TOKEN_SIZE 50

#define MIN_SNAPSHOT_ARRAY_SIZE 16 /* See MS-SMB2 section 3.3.5.15.1 */

/*
 * Input buffer contains (empty) struct smb_snapshot array with size filled in
 * For output see struct SRV_SNAPSHOT_ARRAY in MS-SMB2 section 2.2.32.2
 */
static int
smb3_enum_snapshots(const unsigned int xid, struct cifs_tcon *tcon,
                   struct cifsFileInfo *cfile, void __user *ioc_buf)
{
        char *retbuf = NULL;
        unsigned int ret_data_len = 0;
        int rc;
        u32 max_response_size;
        struct smb_snapshot_array snapshot_in;

        if (get_user(ret_data_len, (unsigned int __user *)ioc_buf))
                return -EFAULT;

        /*
         * Note that for snapshot queries that servers like Azure expect that
         * the first query be minimal size (and just used to get the number/size
         * of previous versions) so response size must be specified as EXACTLY
         * sizeof(struct snapshot_array) which is 16 when rounded up to multiple
         * of eight bytes.
         */
        if (ret_data_len == 0)
                max_response_size = MIN_SNAPSHOT_ARRAY_SIZE;
        else
                max_response_size = CIFSMaxBufSize;

        rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
                        cfile->fid.volatile_fid,
                        FSCTL_SRV_ENUMERATE_SNAPSHOTS,
                        true /* is_fsctl */,
                        NULL, 0 /* no input data */, max_response_size,
                        (char **)&retbuf,
                        &ret_data_len);
        cifs_dbg(FYI, "enum snaphots ioctl returned %d and ret buflen is %d\n",
                        rc, ret_data_len);
        if (rc)
                return rc;

        if (ret_data_len && (ioc_buf != NULL) && (retbuf != NULL)) {
                /* Fixup buffer */
                if (copy_from_user(&snapshot_in, ioc_buf,
                    sizeof(struct smb_snapshot_array))) {
                        rc = -EFAULT;
                        kfree(retbuf);
                        return rc;
                }

                /*
                 * Check for min size, ie not large enough to fit even one GMT
                 * token (snapshot).  On the first ioctl some users may pass in
                 * smaller size (or zero) to simply get the size of the array
                 * so the user space caller can allocate sufficient memory
                 * and retry the ioctl again with larger array size sufficient
                 * to hold all of the snapshot GMT tokens on the second try.
                 */
                if (snapshot_in.snapshot_array_size < GMT_TOKEN_SIZE)
                        ret_data_len = sizeof(struct smb_snapshot_array);

                /*
                 * We return struct SRV_SNAPSHOT_ARRAY, followed by
                 * the snapshot array (of 50 byte GMT tokens) each
                 * representing an available previous version of the data
                 */
                if (ret_data_len > (snapshot_in.snapshot_array_size +
                                        sizeof(struct smb_snapshot_array)))
                        ret_data_len = snapshot_in.snapshot_array_size +
                                        sizeof(struct smb_snapshot_array);

                if (copy_to_user(ioc_buf, retbuf, ret_data_len))
                        rc = -EFAULT;
        }

        kfree(retbuf);
        return rc;
}

static int
smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon,
                     const char *path, struct cifs_sb_info *cifs_sb,
                     struct cifs_fid *fid, __u16 search_flags,
                     struct cifs_search_info *srch_inf)
{
        __le16 *utf16_path;
        int rc;
        __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;

        utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
        if (!utf16_path)
                return -ENOMEM;

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES | FILE_READ_DATA;
        oparms.disposition = FILE_OPEN;
        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;
        oparms.fid = fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL);
        kfree(utf16_path);
        if (rc) {
                cifs_dbg(FYI, "open dir failed rc=%d\n", rc);
                return rc;
        }

        srch_inf->entries_in_buffer = 0;
        srch_inf->index_of_last_entry = 2;

        rc = SMB2_query_directory(xid, tcon, fid->persistent_fid,
                                  fid->volatile_fid, 0, srch_inf);
        if (rc) {
                cifs_dbg(FYI, "query directory failed rc=%d\n", rc);
                SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
        }
        return rc;
}

static int
smb2_query_dir_next(const unsigned int xid, struct cifs_tcon *tcon,
                    struct cifs_fid *fid, __u16 search_flags,
                    struct cifs_search_info *srch_inf)
{
        return SMB2_query_directory(xid, tcon, fid->persistent_fid,
                                    fid->volatile_fid, 0, srch_inf);
}

static int
smb2_close_dir(const unsigned int xid, struct cifs_tcon *tcon,
               struct cifs_fid *fid)
{
        return SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
}

/*
* If we negotiate SMB2 protocol and get STATUS_PENDING - update
* the number of credits and return true. Otherwise - return false.
*/
static bool
smb2_is_status_pending(char *buf, struct TCP_Server_Info *server)
{
        struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;

        if (shdr->Status != STATUS_PENDING)
                return false;

        if (shdr->CreditRequest) {
                spin_lock(&server->req_lock);
                server->credits += le16_to_cpu(shdr->CreditRequest);
                spin_unlock(&server->req_lock);
                wake_up(&server->request_q);
        }

        return true;
}

static bool
smb2_is_session_expired(char *buf)
{
        struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;

        if (shdr->Status != STATUS_NETWORK_SESSION_EXPIRED &&
            shdr->Status != STATUS_USER_SESSION_DELETED)
                return false;

        trace_smb3_ses_expired(shdr->TreeId, shdr->SessionId,
                               le16_to_cpu(shdr->Command),
                               le64_to_cpu(shdr->MessageId));
        cifs_dbg(FYI, "Session expired or deleted\n");

        return true;
}

static int
smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
                     struct cifsInodeInfo *cinode)
{
        if (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
                return SMB2_lease_break(0, tcon, cinode->lease_key,
                                        smb2_get_lease_state(cinode));

        return SMB2_oplock_break(0, tcon, fid->persistent_fid,
                                 fid->volatile_fid,
                                 CIFS_CACHE_READ(cinode) ? 1 : 0);
}

void
smb2_set_related(struct smb_rqst *rqst)
{
        struct smb2_sync_hdr *shdr;

        shdr = (struct smb2_sync_hdr *)(rqst->rq_iov[0].iov_base);
        if (shdr == NULL) {
                cifs_dbg(FYI, "shdr NULL in smb2_set_related\n");
                return;
        }
        shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS;
}

char smb2_padding[7] = {0, 0, 0, 0, 0, 0, 0};

void
smb2_set_next_command(struct cifs_tcon *tcon, struct smb_rqst *rqst)
{
        struct smb2_sync_hdr *shdr;
        struct cifs_ses *ses = tcon->ses;
        struct TCP_Server_Info *server = ses->server;
        unsigned long len = smb_rqst_len(server, rqst);
        int i, num_padding;

        shdr = (struct smb2_sync_hdr *)(rqst->rq_iov[0].iov_base);
        if (shdr == NULL) {
                cifs_dbg(FYI, "shdr NULL in smb2_set_next_command\n");
                return;
        }

        /* SMB headers in a compound are 8 byte aligned. */

        /* No padding needed */
        if (!(len & 7))
                goto finished;

        num_padding = 8 - (len & 7);
        if (!smb3_encryption_required(tcon)) {
                /*
                 * If we do not have encryption then we can just add an extra
                 * iov for the padding.
                 */
                rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding;
                rqst->rq_iov[rqst->rq_nvec].iov_len = num_padding;
                rqst->rq_nvec++;
                len += num_padding;
        } else {
                /*
                 * We can not add a small padding iov for the encryption case
                 * because the encryption framework can not handle the padding
                 * iovs.
                 * We have to flatten this into a single buffer and add
                 * the padding to it.
                 */
                for (i = 1; i < rqst->rq_nvec; i++) {
                        memcpy(rqst->rq_iov[0].iov_base +
                               rqst->rq_iov[0].iov_len,
                               rqst->rq_iov[i].iov_base,
                               rqst->rq_iov[i].iov_len);
                        rqst->rq_iov[0].iov_len += rqst->rq_iov[i].iov_len;
                }
                memset(rqst->rq_iov[0].iov_base + rqst->rq_iov[0].iov_len,
                       0, num_padding);
                rqst->rq_iov[0].iov_len += num_padding;
                len += num_padding;
                rqst->rq_nvec = 1;
        }

 finished:
        shdr->NextCommand = cpu_to_le32(len);
}

/*
 * Passes the query info response back to the caller on success.
 * Caller need to free this with free_rsp_buf().
 */
int
smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
                         __le16 *utf16_path, u32 desired_access,
                         u32 class, u32 type, u32 output_len,
                         struct kvec *rsp, int *buftype,
                         struct cifs_sb_info *cifs_sb)
{
        struct cifs_ses *ses = tcon->ses;
        int flags = 0;
        struct smb_rqst rqst[3];
        int resp_buftype[3];
        struct kvec rsp_iov[3];
        struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
        struct kvec qi_iov[1];
        struct kvec close_iov[1];
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
        int rc;

        if (smb3_encryption_required(tcon))
                flags |= CIFS_TRANSFORM_REQ;

        memset(rqst, 0, sizeof(rqst));
        resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
        memset(rsp_iov, 0, sizeof(rsp_iov));

        memset(&open_iov, 0, sizeof(open_iov));
        rqst[0].rq_iov = open_iov;
        rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;

        oparms.tcon = tcon;
        oparms.desired_access = desired_access;
        oparms.disposition = FILE_OPEN;
        if (cifs_sb && backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, utf16_path);
        if (rc)
                goto qic_exit;
        smb2_set_next_command(tcon, &rqst[0]);

        memset(&qi_iov, 0, sizeof(qi_iov));
        rqst[1].rq_iov = qi_iov;
        rqst[1].rq_nvec = 1;

        rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID, COMPOUND_FID,
                                  class, type, 0,
                                  output_len, 0,
                                  NULL);
        if (rc)
                goto qic_exit;
        smb2_set_next_command(tcon, &rqst[1]);
        smb2_set_related(&rqst[1]);

        memset(&close_iov, 0, sizeof(close_iov));
        rqst[2].rq_iov = close_iov;
        rqst[2].rq_nvec = 1;

        rc = SMB2_close_init(tcon, &rqst[2], COMPOUND_FID, COMPOUND_FID);
        if (rc)
                goto qic_exit;
        smb2_set_related(&rqst[2]);

        rc = compound_send_recv(xid, ses, flags, 3, rqst,
                                resp_buftype, rsp_iov);
        if (rc) {
                free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
                goto qic_exit;
        }
        *rsp = rsp_iov[1];
        *buftype = resp_buftype[1];

 qic_exit:
        SMB2_open_free(&rqst[0]);
        SMB2_query_info_free(&rqst[1]);
        SMB2_close_free(&rqst[2]);
        free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
        free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);
        return rc;
}

static int
smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
             struct kstatfs *buf)
{
        struct smb2_query_info_rsp *rsp;
        struct smb2_fs_full_size_info *info = NULL;
        __le16 utf16_path = 0; /* Null - open root of share */
        struct kvec rsp_iov = {NULL, 0};
        int buftype = CIFS_NO_BUFFER;
        int rc;


        rc = smb2_query_info_compound(xid, tcon, &utf16_path,
                                      FILE_READ_ATTRIBUTES,
                                      FS_FULL_SIZE_INFORMATION,
                                      SMB2_O_INFO_FILESYSTEM,
                                      sizeof(struct smb2_fs_full_size_info),
                                      &rsp_iov, &buftype, NULL);
        if (rc)
                goto qfs_exit;

        rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
        buf->f_type = SMB2_MAGIC_NUMBER;
        info = (struct smb2_fs_full_size_info *)(
                le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
        rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
                               le32_to_cpu(rsp->OutputBufferLength),
                               &rsp_iov,
                               sizeof(struct smb2_fs_full_size_info));
        if (!rc)
                smb2_copy_fs_info_to_kstatfs(info, buf);

qfs_exit:
        free_rsp_buf(buftype, rsp_iov.iov_base);
        return rc;
}

static int
smb311_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
             struct kstatfs *buf)
{
        int rc;
        __le16 srch_path = 0; /* Null - open root of share */
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;

        if (!tcon->posix_extensions)
                return smb2_queryfs(xid, tcon, buf);

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, &srch_path, &oplock, NULL, NULL, NULL);
        if (rc)
                return rc;

        rc = SMB311_posix_qfs_info(xid, tcon, fid.persistent_fid,
                                   fid.volatile_fid, buf);
        buf->f_type = SMB2_MAGIC_NUMBER;
        SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        return rc;
}

static bool
smb2_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
{
        return ob1->fid.persistent_fid == ob2->fid.persistent_fid &&
               ob1->fid.volatile_fid == ob2->fid.volatile_fid;
}

static int
smb2_mand_lock(const unsigned int xid, struct cifsFileInfo *cfile, __u64 offset,
               __u64 length, __u32 type, int lock, int unlock, bool wait)
{
        if (unlock && !lock)
                type = SMB2_LOCKFLAG_UNLOCK;
        return SMB2_lock(xid, tlink_tcon(cfile->tlink),
                         cfile->fid.persistent_fid, cfile->fid.volatile_fid,
                         current->tgid, length, offset, type, wait);
}

static void
smb2_get_lease_key(struct inode *inode, struct cifs_fid *fid)
{
        memcpy(fid->lease_key, CIFS_I(inode)->lease_key, SMB2_LEASE_KEY_SIZE);
}

static void
smb2_set_lease_key(struct inode *inode, struct cifs_fid *fid)
{
        memcpy(CIFS_I(inode)->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
}

static void
smb2_new_lease_key(struct cifs_fid *fid)
{
        generate_random_uuid(fid->lease_key);
}

static int
smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
                   const char *search_name,
                   struct dfs_info3_param **target_nodes,
                   unsigned int *num_of_nodes,
                   const struct nls_table *nls_codepage, int remap)
{
        int rc;
        __le16 *utf16_path = NULL;
        int utf16_path_len = 0;
        struct cifs_tcon *tcon;
        struct fsctl_get_dfs_referral_req *dfs_req = NULL;
        struct get_dfs_referral_rsp *dfs_rsp = NULL;
        u32 dfs_req_size = 0, dfs_rsp_size = 0;

        cifs_dbg(FYI, "smb2_get_dfs_refer path <%s>\n", search_name);

        /*
         * Try to use the IPC tcon, otherwise just use any
         */
        tcon = ses->tcon_ipc;
        if (tcon == NULL) {
                spin_lock(&cifs_tcp_ses_lock);
                tcon = list_first_entry_or_null(&ses->tcon_list,
                                                struct cifs_tcon,
                                                tcon_list);
                if (tcon)
                        tcon->tc_count++;
                spin_unlock(&cifs_tcp_ses_lock);
        }

        if (tcon == NULL) {
                cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n",
                         ses);
                rc = -ENOTCONN;
                goto out;
        }

        utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
                                           &utf16_path_len,
                                           nls_codepage, remap);
        if (!utf16_path) {
                rc = -ENOMEM;
                goto out;
        }

        dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
        dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
        if (!dfs_req) {
                rc = -ENOMEM;
                goto out;
        }

        /* Highest DFS referral version understood */
        dfs_req->MaxReferralLevel = DFS_VERSION;

        /* Path to resolve in an UTF-16 null-terminated string */
        memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);

        do {
                rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
                                FSCTL_DFS_GET_REFERRALS,
                                true /* is_fsctl */,
                                (char *)dfs_req, dfs_req_size, CIFSMaxBufSize,
                                (char **)&dfs_rsp, &dfs_rsp_size);
        } while (rc == -EAGAIN);

        if (rc) {
                if ((rc != -ENOENT) && (rc != -EOPNOTSUPP))
                        cifs_dbg(VFS, "ioctl error in smb2_get_dfs_refer rc=%d\n", rc);
                goto out;
        }

        rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
                                 num_of_nodes, target_nodes,
                                 nls_codepage, remap, search_name,
                                 true /* is_unicode */);
        if (rc) {
                cifs_dbg(VFS, "parse error in smb2_get_dfs_refer rc=%d\n", rc);
                goto out;
        }

 out:
        if (tcon && !tcon->ipc) {
                /* ipc tcons are not refcounted */
                spin_lock(&cifs_tcp_ses_lock);
                tcon->tc_count--;
                spin_unlock(&cifs_tcp_ses_lock);
        }
        kfree(utf16_path);
        kfree(dfs_req);
        kfree(dfs_rsp);
        return rc;
}
#define SMB2_SYMLINK_STRUCT_SIZE \
        (sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp))

static int
smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
                   const char *full_path, char **target_path,
                   struct cifs_sb_info *cifs_sb)
{
        int rc;
        __le16 *utf16_path;
        __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
        struct kvec err_iov = {NULL, 0};
        struct smb2_err_rsp *err_buf = NULL;
        int resp_buftype;
        struct smb2_symlink_err_rsp *symlink;
        unsigned int sub_len;
        unsigned int sub_offset;
        unsigned int print_len;
        unsigned int print_offset;

        cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path);

        utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
        if (!utf16_path)
                return -ENOMEM;

        oparms.tcon = tcon;
        oparms.desired_access = FILE_READ_ATTRIBUTES;
        oparms.disposition = FILE_OPEN;
        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov,
                       &resp_buftype);
        if (!rc)
                SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        if (!rc || !err_iov.iov_base) {
                rc = -ENOENT;
                goto free_path;
        }

        err_buf = err_iov.iov_base;
        if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) ||
            err_iov.iov_len < SMB2_SYMLINK_STRUCT_SIZE) {
                rc = -ENOENT;
                goto querty_exit;
        }

        /* open must fail on symlink - reset rc */
        rc = 0;
        symlink = (struct smb2_symlink_err_rsp *)err_buf->ErrorData;
        sub_len = le16_to_cpu(symlink->SubstituteNameLength);
        sub_offset = le16_to_cpu(symlink->SubstituteNameOffset);
        print_len = le16_to_cpu(symlink->PrintNameLength);
        print_offset = le16_to_cpu(symlink->PrintNameOffset);

        if (err_iov.iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) {
                rc = -ENOENT;
                goto querty_exit;
        }

        if (err_iov.iov_len <
            SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) {
                rc = -ENOENT;
                goto querty_exit;
        }

        *target_path = cifs_strndup_from_utf16(
                                (char *)symlink->PathBuffer + sub_offset,
                                sub_len, true, cifs_sb->local_nls);
        if (!(*target_path)) {
                rc = -ENOMEM;
                goto querty_exit;
        }
        convert_delimiter(*target_path, '/');
        cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);

 querty_exit:
        free_rsp_buf(resp_buftype, err_buf);
 free_path:
        kfree(utf16_path);
        return rc;
}

#ifdef CONFIG_CIFS_ACL
static struct cifs_ntsd *
get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
                const struct cifs_fid *cifsfid, u32 *pacllen)
{
        struct cifs_ntsd *pntsd = NULL;
        unsigned int xid;
        int rc = -EOPNOTSUPP;
        struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

        if (IS_ERR(tlink))
                return ERR_CAST(tlink);

        xid = get_xid();
        cifs_dbg(FYI, "trying to get acl\n");

        rc = SMB2_query_acl(xid, tlink_tcon(tlink), cifsfid->persistent_fid,
                            cifsfid->volatile_fid, (void **)&pntsd, pacllen);
        free_xid(xid);

        cifs_put_tlink(tlink);

        cifs_dbg(FYI, "%s: rc = %d ACL len %d\n", __func__, rc, *pacllen);
        if (rc)
                return ERR_PTR(rc);
        return pntsd;

}

static struct cifs_ntsd *
get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
                const char *path, u32 *pacllen)
{
        struct cifs_ntsd *pntsd = NULL;
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        unsigned int xid;
        int rc;
        struct cifs_tcon *tcon;
        struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
        struct cifs_fid fid;
        struct cifs_open_parms oparms;
        __le16 *utf16_path;

        cifs_dbg(FYI, "get smb3 acl for path %s\n", path);
        if (IS_ERR(tlink))
                return ERR_CAST(tlink);

        tcon = tlink_tcon(tlink);
        xid = get_xid();

        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;

        utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
        if (!utf16_path) {
                rc = -ENOMEM;
                free_xid(xid);
                return ERR_PTR(rc);
        }

        oparms.tcon = tcon;
        oparms.desired_access = READ_CONTROL;
        oparms.disposition = FILE_OPEN;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL);
        kfree(utf16_path);
        if (!rc) {
                rc = SMB2_query_acl(xid, tlink_tcon(tlink), fid.persistent_fid,
                            fid.volatile_fid, (void **)&pntsd, pacllen);
                SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        }

        cifs_put_tlink(tlink);
        free_xid(xid);

        cifs_dbg(FYI, "%s: rc = %d ACL len %d\n", __func__, rc, *pacllen);
        if (rc)
                return ERR_PTR(rc);
        return pntsd;
}

#ifdef CONFIG_CIFS_ACL
static int
set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
                struct inode *inode, const char *path, int aclflag)
{
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        unsigned int xid;
        int rc, access_flags = 0;
        struct cifs_tcon *tcon;
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
        struct cifs_fid fid;
        struct cifs_open_parms oparms;
        __le16 *utf16_path;

        cifs_dbg(FYI, "set smb3 acl for path %s\n", path);
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);

        tcon = tlink_tcon(tlink);
        xid = get_xid();

        if (backup_cred(cifs_sb))
                oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
        else
                oparms.create_options = 0;

        if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
                access_flags = WRITE_OWNER;
        else
                access_flags = WRITE_DAC;

        utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
        if (!utf16_path) {
                rc = -ENOMEM;
                free_xid(xid);
                return rc;
        }

        oparms.tcon = tcon;
        oparms.desired_access = access_flags;
        oparms.disposition = FILE_OPEN;
        oparms.path = path;
        oparms.fid = &fid;
        oparms.reconnect = false;

        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL);
        kfree(utf16_path);
        if (!rc) {
                rc = SMB2_set_acl(xid, tlink_tcon(tlink), fid.persistent_fid,
                            fid.volatile_fid, pnntsd, acllen, aclflag);
                SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
        }

        cifs_put_tlink(tlink);
        free_xid(xid);
        return rc;
}
#endif /* CIFS_ACL */

/* Retrieve an ACL from the server */
static struct cifs_ntsd *
get_smb2_acl(struct cifs_sb_info *cifs_sb,
                                      struct inode *inode, const char *path,
                                      u32 *pacllen)
{
        struct cifs_ntsd *pntsd = NULL;
        struct cifsFileInfo *open_file = NULL;

        if (inode)
                open_file = find_readable_file(CIFS_I(inode), true);
        if (!open_file)
                return get_smb2_acl_by_path(cifs_sb, path, pacllen);

        pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
        cifsFileInfo_put(open_file);
        return pntsd;
}
#endif

static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
                            loff_t offset, loff_t len, bool keep_size)
{
        struct cifs_ses *ses = tcon->ses;
        struct inode *inode;
        struct cifsInodeInfo *cifsi;
        struct cifsFileInfo *cfile = file->private_data;
        struct file_zero_data_information fsctl_buf;
        struct smb_rqst rqst[2];
        int resp_buftype[2];
        struct kvec rsp_iov[2];
        struct kvec io_iov[SMB2_IOCTL_IOV_SIZE];
        struct kvec si_iov[1];
        unsigned int size[1];
        void *data[1];
        long rc;
        unsigned int xid;
        int num = 0, flags = 0;
        __le64 eof;

        xid = get_xid();

        inode = d_inode(cfile->dentry);
        cifsi = CIFS_I(inode);

        trace_smb3_zero_enter(xid, cfile->fid.persistent_fid, tcon->tid,
                              ses->Suid, offset, len);


        /* if file not oplocked can't be sure whether asking to extend size */
        if (!CIFS_CACHE_READ(cifsi))
                if (keep_size == false) {
                        rc = -EOPNOTSUPP;
                        trace_smb3_zero_err(xid, cfile->fid.persistent_fid,
                                tcon->tid, ses->Suid, offset, len, rc);
                        free_xid(xid);
                        return rc;
                }

        /*
         * Must check if file sparse since fallocate -z (zero range) assumes
         * non-sparse allocation
         */
        if (!(cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE)) {
                rc = -EOPNOTSUPP;
                trace_smb3_zero_err(xid, cfile->fid.persistent_fid, tcon->tid,
                              ses->Suid, offset, len, rc);
                free_xid(xid);
                return rc;
        }

        cifs_dbg(FYI, "offset %lld len %lld", offset, len);

        fsctl_buf.FileOffset = cpu_to_le64(offset);
        fsctl_buf.BeyondFinalZero = cpu_to_le64(offset + len);

        if (smb3_encryption_required(tcon))
                flags |= CIFS_TRANSFORM_REQ;

        memset(rqst, 0, sizeof(rqst));
        resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
        memset(rsp_iov, 0, sizeof(rsp_iov));


        memset(&io_iov, 0, sizeof(io_iov));
        rqst[num].rq_iov = io_iov;
        rqst[num].rq_nvec = SMB2_IOCTL_IOV_SIZE;
        rc = SMB2_ioctl_init(tcon, &rqst[num++], cfile->fid.persistent_fid,
                             cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
                             true /* is_fctl */, (char *)&fsctl_buf,
                             sizeof(struct file_zero_data_information),
                             CIFSMaxBufSize);
        if (rc)
                goto zero_range_exit;

        /*
         * do we also need to change the size of the file?
         */
        if (keep_size == false && i_size_read(inode) < offset + len) {
                smb2_set_next_command(tcon, &rqst[0]);

                memset(&si_iov, 0, sizeof(si_iov));
                rqst[num].rq_iov = si_iov;
                rqst[num].rq_nvec = 1;

                eof = cpu_to_le64(offset + len);
                size[0] = 8; /* sizeof __le64 */
                data[0] = &eof;

                rc = SMB2_set_info_init(tcon, &rqst[num++],
                                        cfile->fid.persistent_fid,
                                        cfile->fid.persistent_fid,
                                        current->tgid,
                                        FILE_END_OF_FILE_INFORMATION,
                                        SMB2_O_INFO_FILE, 0, data, size);
                smb2_set_related(&rqst[1]);
        }

        rc = compound_send_recv(xid, ses, flags, num, rqst,
                                resp_buftype, rsp_iov);

 zero_range_exit:
        SMB2_ioctl_free(&rqst[0]);
        SMB2_set_info_free(&rqst[1]);
        free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
        free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
        free_xid(xid);
        if (rc)
                trace_smb3_zero_err(xid, cfile->fid.persistent_fid, tcon->tid,
                              ses->Suid, offset, len, rc);
        else
                trace_smb3_zero_done(xid, cfile->fid.persistent_fid, tcon->tid,
                              ses->Suid, offset, len);
        return rc;
}

static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
                            loff_t offset, loff_t len)
{
        struct inode *inode;
        struct cifsInodeInfo *cifsi;
        struct cifsFileInfo *cfile = file->private_data;
        struct file_zero_data_information fsctl_buf;
        long rc;
        unsigned int xid;
        __u8 set_sparse = 1;

        xid = get_xid();

        inode = d_inode(cfile->dentry);
        cifsi = CIFS_I(inode);

        /* Need to make file sparse, if not already, before freeing range. */
        /* Consider adding equivalent for compressed since it could also work */
        if (!smb2_set_sparse(xid, tcon, cfile, inode, set_sparse)) {
                rc = -EOPNOTSUPP;
                free_xid(xid);
                return rc;
        }

        cifs_dbg(FYI, "offset %lld len %lld", offset, len);

        fsctl_buf.FileOffset = cpu_to_le64(offset);
        fsctl_buf.BeyondFinalZero = cpu_to_le64(offset + len);

        rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
                        cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
                        true /* is_fctl */, (char *)&fsctl_buf,
                        sizeof(struct file_zero_data_information),
                        CIFSMaxBufSize, NULL, NULL);
        free_xid(xid);
        return rc;
}

static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
                            loff_t off, loff_t len, bool keep_size)
{
        struct inode *inode;
        struct cifsInodeInfo *cifsi;
        struct cifsFileInfo *cfile = file->private_data;
        long rc = -EOPNOTSUPP;
        unsigned int xid;
        __le64 eof;

        xid = get_xid();

        inode = d_inode(cfile->dentry);
        cifsi = CIFS_I(inode);

        trace_smb3_falloc_enter(xid, cfile->fid.persistent_fid, tcon->tid,
                                tcon->ses->Suid, off, len);
        /* if file not oplocked can't be sure whether asking to extend size */
        if (!CIFS_CACHE_READ(cifsi))
                if (keep_size == false) {
                        trace_smb3_falloc_err(xid, cfile->fid.persistent_fid,
                                tcon->tid, tcon->ses->Suid, off, len, rc);
                        free_xid(xid);
                        return rc;
                }

        /*
         * Files are non-sparse by default so falloc may be a no-op
         * Must check if file sparse. If not sparse, and not extending
         * then no need to do anything since file already allocated
         */
        if ((cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) == 0) {
                if (keep_size == true)
                        rc = 0;
                /* check if extending file */
                else if (i_size_read(inode) >= off + len)
                        /* not extending file and already not sparse */
                        rc = 0;
                /* BB: in future add else clause to extend file */
                else
                        rc = -EOPNOTSUPP;
                if (rc)
                        trace_smb3_falloc_err(xid, cfile->fid.persistent_fid,
                                tcon->tid, tcon->ses->Suid, off, len, rc);
                else
                        trace_smb3_falloc_done(xid, cfile->fid.persistent_fid,
                                tcon->tid, tcon->ses->Suid, off, len);
                free_xid(xid);
                return rc;
        }

        if ((keep_size == true) || (i_size_read(inode) >= off + len)) {
                /*
                 * Check if falloc starts within first few pages of file
                 * and ends within a few pages of the end of file to
                 * ensure that most of file is being forced to be
                 * fallocated now. If so then setting whole file sparse
                 * ie potentially making a few extra pages at the beginning
                 * or end of the file non-sparse via set_sparse is harmless.
                 */
                if ((off > 8192) || (off + len + 8192 < i_size_read(inode))) {
                        rc = -EOPNOTSUPP;
                        trace_smb3_falloc_err(xid, cfile->fid.persistent_fid,
                                tcon->tid, tcon->ses->Suid, off, len, rc);
                        free_xid(xid);
                        return rc;
                }

                smb2_set_sparse(xid, tcon, cfile, inode, false);
                rc = 0;
        } else {
                smb2_set_sparse(xid, tcon, cfile, inode, false);
                rc = 0;
                if (i_size_read(inode) < off + len) {
                        eof = cpu_to_le64(off + len);
                        rc = SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
                                          cfile->fid.volatile_fid, cfile->pid,
                                          &eof);
                }
        }

        if (rc)
                trace_smb3_falloc_err(xid, cfile->fid.persistent_fid, tcon->tid,
                                tcon->ses->Suid, off, len, rc);
        else
                trace_smb3_falloc_done(xid, cfile->fid.persistent_fid, tcon->tid,
                                tcon->ses->Suid, off, len);

        free_xid(xid);
        return rc;
}


static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode,
                           loff_t off, loff_t len)
{
        /* KEEP_SIZE already checked for by do_fallocate */
        if (mode & FALLOC_FL_PUNCH_HOLE)
                return smb3_punch_hole(file, tcon, off, len);
        else if (mode & FALLOC_FL_ZERO_RANGE) {
                if (mode & FALLOC_FL_KEEP_SIZE)
                        return smb3_zero_range(file, tcon, off, len, true);
                return smb3_zero_range(file, tcon, off, len, false);
        } else if (mode == FALLOC_FL_KEEP_SIZE)
                return smb3_simple_falloc(file, tcon, off, len, true);
        else if (mode == 0)
                return smb3_simple_falloc(file, tcon, off, len, false);

        return -EOPNOTSUPP;
}

static void
smb2_downgrade_oplock(struct TCP_Server_Info *server,
                        struct cifsInodeInfo *cinode, bool set_level2)
{
        if (set_level2)
                server->ops->set_oplock_level(cinode, SMB2_OPLOCK_LEVEL_II,
                                                0, NULL);
        else
                server->ops->set_oplock_level(cinode, 0, 0, NULL);
}

static void
smb21_downgrade_oplock(struct TCP_Server_Info *server,
                       struct cifsInodeInfo *cinode, bool set_level2)
{
        server->ops->set_oplock_level(cinode,
                                      set_level2 ? SMB2_LEASE_READ_CACHING_HE :
                                      0, 0, NULL);
}

static void
smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock,
                      unsigned int epoch, bool *purge_cache)
{
        oplock &= 0xFF;
        if (oplock == SMB2_OPLOCK_LEVEL_NOCHANGE)
                return;
        if (oplock == SMB2_OPLOCK_LEVEL_BATCH) {
                cinode->oplock = CIFS_CACHE_RHW_FLG;
                cifs_dbg(FYI, "Batch Oplock granted on inode %p\n",
                         &cinode->vfs_inode);
        } else if (oplock == SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
                cinode->oplock = CIFS_CACHE_RW_FLG;
                cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
                         &cinode->vfs_inode);
        } else if (oplock == SMB2_OPLOCK_LEVEL_II) {
                cinode->oplock = CIFS_CACHE_READ_FLG;
                cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
                         &cinode->vfs_inode);
        } else
                cinode->oplock = 0;
}

static void
smb21_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock,
                       unsigned int epoch, bool *purge_cache)
{
        char message[5] = {0};

        oplock &= 0xFF;
        if (oplock == SMB2_OPLOCK_LEVEL_NOCHANGE)
                return;

        cinode->oplock = 0;
        if (oplock & SMB2_LEASE_READ_CACHING_HE) {
                cinode->oplock |= CIFS_CACHE_READ_FLG;
                strcat(message, "R");
        }
        if (oplock & SMB2_LEASE_HANDLE_CACHING_HE) {
                cinode->oplock |= CIFS_CACHE_HANDLE_FLG;
                strcat(message, "H");
        }
        if (oplock & SMB2_LEASE_WRITE_CACHING_HE) {
                cinode->oplock |= CIFS_CACHE_WRITE_FLG;
                strcat(message, "W");
        }
        if (!cinode->oplock)
                strcat(message, "None");
        cifs_dbg(FYI, "%s Lease granted on inode %p\n", message,
                 &cinode->vfs_inode);
}

static void
smb3_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock,
                      unsigned int epoch, bool *purge_cache)
{
        unsigned int old_oplock = cinode->oplock;

        smb21_set_oplock_level(cinode, oplock, epoch, purge_cache);

        if (purge_cache) {
                *purge_cache = false;
                if (old_oplock == CIFS_CACHE_READ_FLG) {
                        if (cinode->oplock == CIFS_CACHE_READ_FLG &&
                            (epoch - cinode->epoch > 0))
                                *purge_cache = true;
                        else if (cinode->oplock == CIFS_CACHE_RH_FLG &&
                                 (epoch - cinode->epoch > 1))
                                *purge_cache = true;
                        else if (cinode->oplock == CIFS_CACHE_RHW_FLG &&
                                 (epoch - cinode->epoch > 1))
                                *purge_cache = true;
                        else if (cinode->oplock == 0 &&
                                 (epoch - cinode->epoch > 0))
                                *purge_cache = true;
                } else if (old_oplock == CIFS_CACHE_RH_FLG) {
                        if (cinode->oplock == CIFS_CACHE_RH_FLG &&
                            (epoch - cinode->epoch > 0))
                                *purge_cache = true;
                        else if (cinode->oplock == CIFS_CACHE_RHW_FLG &&
                                 (epoch - cinode->epoch > 1))
                                *purge_cache = true;
                }
                cinode->epoch = epoch;
        }
}

static bool
smb2_is_read_op(__u32 oplock)
{
        return oplock == SMB2_OPLOCK_LEVEL_II;
}

static bool
smb21_is_read_op(__u32 oplock)
{
        return (oplock & SMB2_LEASE_READ_CACHING_HE) &&
               !(oplock & SMB2_LEASE_WRITE_CACHING_HE);
}