// SPDX-License-Identifier: GPL-2.0
/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/obdclass/obd_mount.c
 *
 * Client mount routines
 *
 * Author: Nathan Rutman <nathan@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_CLASS
#define D_MOUNT (D_SUPER | D_CONFIG/*|D_WARNING */)
#define PRINT_CMD CDEBUG

#include <obd.h>
#include <lustre_compat.h>
#include <obd_class.h>
#include <uapi/linux/lustre/lustre_idl.h>
#include <lustre_log.h>
#include <lustre_disk.h>
#include <uapi/linux/lustre/lustre_param.h>

static DEFINE_SPINLOCK(client_lock);
static struct module *client_mod;
static int (*client_fill_super)(struct super_block *sb);
static void (*kill_super_cb)(struct super_block *sb);

/**************** config llog ********************/

/** Get a config log from the MGS and process it.
 * This func is called for both clients and servers.
 * Continue to process new statements appended to the logs
 * (whenever the config lock is revoked) until lustre_end_log
 * is called.
 * @param sb The superblock is used by the MGC to write to the local copy of
 *   the config log
 * @param logname The name of the llog to replicate from the MGS
 * @param cfg Since the same mgc may be used to follow multiple config logs
 *   (e.g. ost1, ost2, client), the config_llog_instance keeps the state for
 *   this log, and is added to the mgc's list of logs to follow.
 */
int lustre_process_log(struct super_block *sb, char *logname,
                       struct config_llog_instance *cfg)
{
        struct lustre_cfg *lcfg;
        struct lustre_cfg_bufs *bufs;
        struct lustre_sb_info *lsi = s2lsi(sb);
        struct obd_device *mgc = lsi->lsi_mgc;
        int rc;

        LASSERT(mgc);
        LASSERT(cfg);

        bufs = kzalloc(sizeof(*bufs), GFP_NOFS);
        if (!bufs)
                return -ENOMEM;

        /* mgc_process_config */
        lustre_cfg_bufs_reset(bufs, mgc->obd_name);
        lustre_cfg_bufs_set_string(bufs, 1, logname);
        lustre_cfg_bufs_set(bufs, 2, cfg, sizeof(*cfg));
        lustre_cfg_bufs_set(bufs, 3, &sb, sizeof(sb));
        lcfg = kzalloc(lustre_cfg_len(bufs->lcfg_bufcount, bufs->lcfg_buflen),
                       GFP_NOFS);
        if (!lcfg) {
                rc = -ENOMEM;
                goto out;
        }
        lustre_cfg_init(lcfg, LCFG_LOG_START, bufs);

        rc = obd_process_config(mgc, sizeof(*lcfg), lcfg);
        kfree(lcfg);
out:
        kfree(bufs);

        if (rc == -EINVAL)
                LCONSOLE_ERROR_MSG(0x15b, "%s: The configuration from log '%s' failed from the MGS (%d).  Make sure this client and the MGS are running compatible versions of Lustre.\n",
                                   mgc->obd_name, logname, rc);

        else if (rc)
                LCONSOLE_ERROR_MSG(0x15c, "%s: The configuration from log '%s' failed (%d). This may be the result of communication errors between this node and the MGS, a bad configuration, or other errors. See the syslog for more information.\n",
                                   mgc->obd_name, logname,
                                   rc);

        /* class_obd_list(); */
        return rc;
}
EXPORT_SYMBOL(lustre_process_log);

/* Stop watching this config log for updates */
int lustre_end_log(struct super_block *sb, char *logname,
                   struct config_llog_instance *cfg)
{
        struct lustre_cfg *lcfg;
        struct lustre_cfg_bufs bufs;
        struct lustre_sb_info *lsi = s2lsi(sb);
        struct obd_device *mgc = lsi->lsi_mgc;
        int rc;

        if (!mgc)
                return -ENOENT;

        /* mgc_process_config */
        lustre_cfg_bufs_reset(&bufs, mgc->obd_name);
        lustre_cfg_bufs_set_string(&bufs, 1, logname);
        if (cfg)
                lustre_cfg_bufs_set(&bufs, 2, cfg, sizeof(*cfg));
        lcfg = kzalloc(lustre_cfg_len(bufs.lcfg_bufcount, bufs.lcfg_buflen),
                       GFP_NOFS);
        if (!lcfg)
                return -ENOMEM;
        lustre_cfg_init(lcfg, LCFG_LOG_END, &bufs);

        rc = obd_process_config(mgc, sizeof(*lcfg), lcfg);
        kfree(lcfg);
        return rc;
}
EXPORT_SYMBOL(lustre_end_log);

/**************** obd start *******************/

/** lustre_cfg_bufs are a holdover from 1.4; we can still set these up from
 * lctl (and do for echo cli/srv.
 */
static int do_lcfg(char *cfgname, lnet_nid_t nid, int cmd,
                   char *s1, char *s2, char *s3, char *s4)
{
        struct lustre_cfg_bufs bufs;
        struct lustre_cfg     *lcfg = NULL;
        int rc;

        CDEBUG(D_TRACE, "lcfg %s %#x %s %s %s %s\n", cfgname,
               cmd, s1, s2, s3, s4);

        lustre_cfg_bufs_reset(&bufs, cfgname);
        if (s1)
                lustre_cfg_bufs_set_string(&bufs, 1, s1);
        if (s2)
                lustre_cfg_bufs_set_string(&bufs, 2, s2);
        if (s3)
                lustre_cfg_bufs_set_string(&bufs, 3, s3);
        if (s4)
                lustre_cfg_bufs_set_string(&bufs, 4, s4);

        lcfg = kzalloc(lustre_cfg_len(bufs.lcfg_bufcount, bufs.lcfg_buflen),
                       GFP_NOFS);
        if (!lcfg)
                return -ENOMEM;
        lustre_cfg_init(lcfg, cmd, &bufs);
        lcfg->lcfg_nid = nid;
        rc = class_process_config(lcfg);
        kfree(lcfg);
        return rc;
}

/** Call class_attach and class_setup.  These methods in turn call
 * obd type-specific methods.
 */
static int lustre_start_simple(char *obdname, char *type, char *uuid,
                               char *s1, char *s2, char *s3, char *s4)
{
        int rc;

        CDEBUG(D_MOUNT, "Starting obd %s (typ=%s)\n", obdname, type);

        rc = do_lcfg(obdname, 0, LCFG_ATTACH, type, uuid, NULL, NULL);
        if (rc) {
                CERROR("%s attach error %d\n", obdname, rc);
                return rc;
        }
        rc = do_lcfg(obdname, 0, LCFG_SETUP, s1, s2, s3, s4);
        if (rc) {
                CERROR("%s setup error %d\n", obdname, rc);
                do_lcfg(obdname, 0, LCFG_DETACH, NULL, NULL, NULL, NULL);
        }
        return rc;
}

static DEFINE_MUTEX(mgc_start_lock);

/** Set up a mgc obd to process startup logs
 *
 * \param sb [in] super block of the mgc obd
 *
 * \retval 0 success, otherwise error code
 */
int lustre_start_mgc(struct super_block *sb)
{
        struct obd_connect_data *data = NULL;
        struct lustre_sb_info *lsi = s2lsi(sb);
        struct obd_device *obd;
        struct obd_export *exp;
        struct obd_uuid *uuid;
        class_uuid_t uuidc;
        lnet_nid_t nid;
        char nidstr[LNET_NIDSTR_SIZE];
        char *mgcname = NULL, *niduuid = NULL, *mgssec = NULL;
        char *ptr;
        int rc = 0, i = 0, j;

        LASSERT(lsi->lsi_lmd);

        /* Use nids from mount line: uml1,1@elan:uml2,2@elan:/lustre */
        ptr = lsi->lsi_lmd->lmd_dev;
        if (class_parse_nid(ptr, &nid, &ptr) == 0)
                i++;
        if (i == 0) {
                CERROR("No valid MGS nids found.\n");
                return -EINVAL;
        }

        mutex_lock(&mgc_start_lock);

        libcfs_nid2str_r(nid, nidstr, sizeof(nidstr));
        mgcname = kasprintf(GFP_NOFS,
                            "%s%s", LUSTRE_MGC_OBDNAME, nidstr);
        niduuid = kasprintf(GFP_NOFS, "%s_%x", mgcname, 0);
        if (!mgcname || !niduuid) {
                rc = -ENOMEM;
                goto out_free;
        }

        mgssec = lsi->lsi_lmd->lmd_mgssec ? lsi->lsi_lmd->lmd_mgssec : "";

        data = kzalloc(sizeof(*data), GFP_NOFS);
        if (!data) {
                rc = -ENOMEM;
                goto out_free;
        }

        obd = class_name2obd(mgcname);
        if (obd && !obd->obd_stopping) {
                int recov_bk;

                rc = obd_set_info_async(NULL, obd->obd_self_export,
                                        strlen(KEY_MGSSEC), KEY_MGSSEC,
                                        strlen(mgssec), mgssec, NULL);
                if (rc)
                        goto out_free;

                /* Re-using an existing MGC */
                atomic_inc(&obd->u.cli.cl_mgc_refcount);

                /* IR compatibility check, only for clients */
                if (lmd_is_client(lsi->lsi_lmd)) {
                        int has_ir;
                        int vallen = sizeof(*data);
                        __u32 *flags = &lsi->lsi_lmd->lmd_flags;

                        rc = obd_get_info(NULL, obd->obd_self_export,
                                          strlen(KEY_CONN_DATA), KEY_CONN_DATA,
                                          &vallen, data);
                        LASSERT(rc == 0);
                        has_ir = OCD_HAS_FLAG(data, IMP_RECOV);
                        if (has_ir ^ !(*flags & LMD_FLG_NOIR)) {
                                /* LMD_FLG_NOIR is for test purpose only */
                                LCONSOLE_WARN(
                                        "Trying to mount a client with IR setting not compatible with current mgc. Force to use current mgc setting that is IR %s.\n",
                                        has_ir ? "enabled" : "disabled");
                                if (has_ir)
                                        *flags &= ~LMD_FLG_NOIR;
                                else
                                        *flags |= LMD_FLG_NOIR;
                        }
                }

                recov_bk = 0;

                /* Try all connections, but only once (again).
                 * We don't want to block another target from starting
                 * (using its local copy of the log), but we do want to connect
                 * if at all possible.
                 */
                recov_bk++;
                CDEBUG(D_MOUNT, "%s: Set MGC reconnect %d\n", mgcname,
                       recov_bk);
                rc = obd_set_info_async(NULL, obd->obd_self_export,
                                        sizeof(KEY_INIT_RECOV_BACKUP),
                                        KEY_INIT_RECOV_BACKUP,
                                        sizeof(recov_bk), &recov_bk, NULL);
                rc = 0;
                goto out;
        }

        CDEBUG(D_MOUNT, "Start MGC '%s'\n", mgcname);

        /* Add the primary nids for the MGS */
        i = 0;
        /* Use nids from mount line: uml1,1@elan:uml2,2@elan:/lustre */
        ptr = lsi->lsi_lmd->lmd_dev;
        while (class_parse_nid(ptr, &nid, &ptr) == 0) {
                rc = do_lcfg(mgcname, nid,
                             LCFG_ADD_UUID, niduuid, NULL, NULL, NULL);
                if (!rc)
                        i++;
                /* Stop at the first failover nid */
                if (*ptr == ':')
                        break;
        }
        if (i == 0) {
                CERROR("No valid MGS nids found.\n");
                rc = -EINVAL;
                goto out_free;
        }
        lsi->lsi_lmd->lmd_mgs_failnodes = 1;

        /* Random uuid for MGC allows easier reconnects */
        uuid = kzalloc(sizeof(*uuid), GFP_NOFS);
        if (!uuid) {
                rc = -ENOMEM;
                goto out_free;
        }

        ll_generate_random_uuid(uuidc);
        class_uuid_unparse(uuidc, uuid);

        /* Start the MGC */
        rc = lustre_start_simple(mgcname, LUSTRE_MGC_NAME,
                                 (char *)uuid->uuid, LUSTRE_MGS_OBDNAME,
                                 niduuid, NULL, NULL);
        kfree(uuid);
        if (rc)
                goto out_free;

        /* Add any failover MGS nids */
        i = 1;
        while (ptr && ((*ptr == ':' ||
                        class_find_param(ptr, PARAM_MGSNODE, &ptr) == 0))) {
                /* New failover node */
                sprintf(niduuid, "%s_%x", mgcname, i);
                j = 0;
                while (class_parse_nid_quiet(ptr, &nid, &ptr) == 0) {
                        rc = do_lcfg(mgcname, nid, LCFG_ADD_UUID, niduuid,
                                     NULL, NULL, NULL);
                        if (!rc)
                                ++j;
                        if (*ptr == ':')
                                break;
                }
                if (j > 0) {
                        rc = do_lcfg(mgcname, 0, LCFG_ADD_CONN,
                                     niduuid, NULL, NULL, NULL);
                        if (!rc)
                                i++;
                } else {
                        /* at ":/fsname" */
                        break;
                }
        }
        lsi->lsi_lmd->lmd_mgs_failnodes = i;

        obd = class_name2obd(mgcname);
        if (!obd) {
                CERROR("Can't find mgcobd %s\n", mgcname);
                rc = -ENOTCONN;
                goto out_free;
        }

        rc = obd_set_info_async(NULL, obd->obd_self_export,
                                strlen(KEY_MGSSEC), KEY_MGSSEC,
                                strlen(mgssec), mgssec, NULL);
        if (rc)
                goto out_free;

        /* Keep a refcount of servers/clients who started with "mount",
         * so we know when we can get rid of the mgc.
         */
        atomic_set(&obd->u.cli.cl_mgc_refcount, 1);

        /* We connect to the MGS at setup, and don't disconnect until cleanup */
        data->ocd_connect_flags = OBD_CONNECT_VERSION | OBD_CONNECT_AT |
                                  OBD_CONNECT_FULL20 | OBD_CONNECT_IMP_RECOV |
                                  OBD_CONNECT_LVB_TYPE | OBD_CONNECT_BULK_MBITS;

#if OBD_OCD_VERSION(3, 0, 53, 0) > LUSTRE_VERSION_CODE
        data->ocd_connect_flags |= OBD_CONNECT_MNE_SWAB;
#endif

        if (lmd_is_client(lsi->lsi_lmd) &&
            lsi->lsi_lmd->lmd_flags & LMD_FLG_NOIR)
                data->ocd_connect_flags &= ~OBD_CONNECT_IMP_RECOV;
        data->ocd_version = LUSTRE_VERSION_CODE;
        rc = obd_connect(NULL, &exp, obd, &obd->obd_uuid, data, NULL);
        if (rc) {
                CERROR("connect failed %d\n", rc);
                goto out;
        }

        obd->u.cli.cl_mgc_mgsexp = exp;

out:
        /* Keep the mgc info in the sb. Note that many lsi's can point
         * to the same mgc.
         */
        lsi->lsi_mgc = obd;
out_free:
        mutex_unlock(&mgc_start_lock);

        kfree(data);
        kfree(mgcname);
        kfree(niduuid);
        return rc;
}

static int lustre_stop_mgc(struct super_block *sb)
{
        struct lustre_sb_info *lsi = s2lsi(sb);
        struct obd_device *obd;
        char *niduuid = NULL, *ptr = NULL;
        int i, rc = 0, len = 0;

        if (!lsi)
                return -ENOENT;
        obd = lsi->lsi_mgc;
        if (!obd)
                return -ENOENT;
        lsi->lsi_mgc = NULL;

        mutex_lock(&mgc_start_lock);
        LASSERT(atomic_read(&obd->u.cli.cl_mgc_refcount) > 0);
        if (!atomic_dec_and_test(&obd->u.cli.cl_mgc_refcount)) {
                /* This is not fatal, every client that stops
                 * will call in here.
                 */
                CDEBUG(D_MOUNT, "mgc still has %d references.\n",
                       atomic_read(&obd->u.cli.cl_mgc_refcount));
                rc = -EBUSY;
                goto out;
        }

        /* The MGC has no recoverable data in any case.
         * force shutdown set in umount_begin
         */
        obd->obd_no_recov = 1;

        if (obd->u.cli.cl_mgc_mgsexp) {
                /* An error is not fatal, if we are unable to send the
                 * disconnect mgs ping evictor cleans up the export
                 */
                rc = obd_disconnect(obd->u.cli.cl_mgc_mgsexp);
                if (rc)
                        CDEBUG(D_MOUNT, "disconnect failed %d\n", rc);
        }

        /* Save the obdname for cleaning the nid uuids, which are obdname_XX */
        len = strlen(obd->obd_name) + 6;
        niduuid = kzalloc(len, GFP_NOFS);
        if (niduuid) {
                strcpy(niduuid, obd->obd_name);
                ptr = niduuid + strlen(niduuid);
        }

        rc = class_manual_cleanup(obd);
        if (rc)
                goto out;

        /* Clean the nid uuids */
        if (!niduuid) {
                rc = -ENOMEM;
                goto out;
        }

        for (i = 0; i < lsi->lsi_lmd->lmd_mgs_failnodes; i++) {
                sprintf(ptr, "_%x", i);
                rc = do_lcfg(LUSTRE_MGC_OBDNAME, 0, LCFG_DEL_UUID,
                             niduuid, NULL, NULL, NULL);
                if (rc)
                        CERROR("del MDC UUID %s failed: rc = %d\n",
                               niduuid, rc);
        }
out:
        kfree(niduuid);

        /* class_import_put will get rid of the additional connections */
        mutex_unlock(&mgc_start_lock);
        return rc;
}

/***************** lustre superblock **************/

static struct lustre_sb_info *lustre_init_lsi(struct super_block *sb)
{
        struct lustre_sb_info *lsi;

        lsi = kzalloc(sizeof(*lsi), GFP_NOFS);
        if (!lsi)
                return NULL;
        lsi->lsi_lmd = kzalloc(sizeof(*lsi->lsi_lmd), GFP_NOFS);
        if (!lsi->lsi_lmd) {
                kfree(lsi);
                return NULL;
        }

        lsi->lsi_lmd->lmd_exclude_count = 0;
        lsi->lsi_lmd->lmd_recovery_time_soft = 0;
        lsi->lsi_lmd->lmd_recovery_time_hard = 0;
        s2lsi_nocast(sb) = lsi;
        /* we take 1 extra ref for our setup */
        atomic_set(&lsi->lsi_mounts, 1);

        /* Default umount style */
        lsi->lsi_flags = LSI_UMOUNT_FAILOVER;

        return lsi;
}

static int lustre_free_lsi(struct super_block *sb)
{
        struct lustre_sb_info *lsi = s2lsi(sb);

        CDEBUG(D_MOUNT, "Freeing lsi %p\n", lsi);

        /* someone didn't call server_put_mount. */
        LASSERT(atomic_read(&lsi->lsi_mounts) == 0);

        if (lsi->lsi_lmd) {
                kfree(lsi->lsi_lmd->lmd_dev);
                kfree(lsi->lsi_lmd->lmd_profile);
                kfree(lsi->lsi_lmd->lmd_mgssec);
                kfree(lsi->lsi_lmd->lmd_opts);
                if (lsi->lsi_lmd->lmd_exclude_count)
                        kfree(lsi->lsi_lmd->lmd_exclude);
                kfree(lsi->lsi_lmd->lmd_mgs);
                kfree(lsi->lsi_lmd->lmd_osd_type);
                kfree(lsi->lsi_lmd->lmd_params);

                kfree(lsi->lsi_lmd);
        }

        LASSERT(!lsi->lsi_llsbi);
        kfree(lsi);
        s2lsi_nocast(sb) = NULL;

        return 0;
}

/* The lsi has one reference for every server that is using the disk -
 * e.g. MDT, MGS, and potentially MGC
 */
static int lustre_put_lsi(struct super_block *sb)
{
        struct lustre_sb_info *lsi = s2lsi(sb);

        CDEBUG(D_MOUNT, "put %p %d\n", sb, atomic_read(&lsi->lsi_mounts));
        if (atomic_dec_and_test(&lsi->lsi_mounts)) {
                lustre_free_lsi(sb);
                return 1;
        }
        return 0;
}

/*** SERVER NAME ***
 * <FSNAME><SEPARATOR><TYPE><INDEX>
 * FSNAME is between 1 and 8 characters (inclusive).
 *      Excluded characters are '/' and ':'
 * SEPARATOR is either ':' or '-'
 * TYPE: "OST", "MDT", etc.
 * INDEX: Hex representation of the index
 */

/** Get the fsname ("lustre") from the server name ("lustre-OST003F").
 * @param [in] svname server name including type and index
 * @param [out] fsname Buffer to copy filesystem name prefix into.
 *  Must have at least 'strlen(fsname) + 1' chars.
 * @param [out] endptr if endptr isn't NULL it is set to end of fsname
 * rc < 0  on error
 */
static int server_name2fsname(const char *svname, char *fsname,
                              const char **endptr)
{
        const char *dash;

        dash = svname + strnlen(svname, 8); /* max fsname length is 8 */
        for (; dash > svname && *dash != '-' && *dash != ':'; dash--)
                ;
        if (dash == svname)
                return -EINVAL;

        if (fsname) {
                strncpy(fsname, svname, dash - svname);
                fsname[dash - svname] = '\0';
        }

        if (endptr)
                *endptr = dash;

        return 0;
}

/* Get the index from the obd name.
 *  rc = server type, or
 * rc < 0  on error
 * if endptr isn't NULL it is set to end of name
 */
static int server_name2index(const char *svname, __u32 *idx,
                             const char **endptr)
{
        unsigned long index;
        int rc;
        const char *dash;

        /* We use server_name2fsname() just for parsing */
        rc = server_name2fsname(svname, NULL, &dash);
        if (rc != 0)
                return rc;

        dash++;

        if (strncmp(dash, "MDT", 3) == 0)
                rc = LDD_F_SV_TYPE_MDT;
        else if (strncmp(dash, "OST", 3) == 0)
                rc = LDD_F_SV_TYPE_OST;
        else
                return -EINVAL;

        dash += 3;

        if (strncmp(dash, "all", 3) == 0) {
                if (endptr)
                        *endptr = dash + 3;
                return rc | LDD_F_SV_ALL;
        }

        index = simple_strtoul(dash, (char **)endptr, 16);
        if (idx)
                *idx = index;

        /* Account for -mdc after index that is possible when specifying mdt */
        if (endptr && strncmp(LUSTRE_MDC_NAME, *endptr + 1,
                              sizeof(LUSTRE_MDC_NAME) - 1) == 0)
                *endptr += sizeof(LUSTRE_MDC_NAME);

        return rc;
}

/*************** mount common between server and client ***************/

/* Common umount */
int lustre_common_put_super(struct super_block *sb)
{
        int rc;

        CDEBUG(D_MOUNT, "dropping sb %p\n", sb);

        /* Drop a ref to the MGC */
        rc = lustre_stop_mgc(sb);
        if (rc && (rc != -ENOENT)) {
                if (rc != -EBUSY) {
                        CERROR("Can't stop MGC: %d\n", rc);
                        return rc;
                }
                /* BUSY just means that there's some other obd that
                 * needs the mgc.  Let him clean it up.
                 */
                CDEBUG(D_MOUNT, "MGC still in use\n");
        }
        /* Drop a ref to the mounted disk */
        lustre_put_lsi(sb);
        return rc;
}
EXPORT_SYMBOL(lustre_common_put_super);

static void lmd_print(struct lustre_mount_data *lmd)
{
        int i;

        PRINT_CMD(D_MOUNT, "  mount data:\n");
        if (lmd_is_client(lmd))
                PRINT_CMD(D_MOUNT, "profile: %s\n", lmd->lmd_profile);
        PRINT_CMD(D_MOUNT, "device:  %s\n", lmd->lmd_dev);
        PRINT_CMD(D_MOUNT, "flags:   %x\n", lmd->lmd_flags);

        if (lmd->lmd_opts)
                PRINT_CMD(D_MOUNT, "options: %s\n", lmd->lmd_opts);

        if (lmd->lmd_recovery_time_soft)
                PRINT_CMD(D_MOUNT, "recovery time soft: %d\n",
                          lmd->lmd_recovery_time_soft);

        if (lmd->lmd_recovery_time_hard)
                PRINT_CMD(D_MOUNT, "recovery time hard: %d\n",
                          lmd->lmd_recovery_time_hard);

        for (i = 0; i < lmd->lmd_exclude_count; i++) {
                PRINT_CMD(D_MOUNT, "exclude %d:  OST%04x\n", i,
                          lmd->lmd_exclude[i]);
        }
}

/* Is this server on the exclusion list */
int lustre_check_exclusion(struct super_block *sb, char *svname)
{
        struct lustre_sb_info *lsi = s2lsi(sb);
        struct lustre_mount_data *lmd = lsi->lsi_lmd;
        __u32 index;
        int i, rc;

        rc = server_name2index(svname, &index, NULL);
        if (rc != LDD_F_SV_TYPE_OST)
                /* Only exclude OSTs */
                return 0;

        CDEBUG(D_MOUNT, "Check exclusion %s (%d) in %d of %s\n", svname,
               index, lmd->lmd_exclude_count, lmd->lmd_dev);

        for (i = 0; i < lmd->lmd_exclude_count; i++) {
                if (index == lmd->lmd_exclude[i]) {
                        CWARN("Excluding %s (on exclusion list)\n", svname);
                        return 1;
                }
        }
        return 0;
}

/* mount -v  -o exclude=lustre-OST0001:lustre-OST0002 -t lustre ... */
static int lmd_make_exclusion(struct lustre_mount_data *lmd, const char *ptr)
{
        const char *s1 = ptr, *s2;
        __u32 index = 0, *exclude_list;
        int rc = 0, devmax;

        /* The shortest an ost name can be is 8 chars: -OST0000.
         * We don't actually know the fsname at this time, so in fact
         * a user could specify any fsname.
         */
        devmax = strlen(ptr) / 8 + 1;

        /* temp storage until we figure out how many we have */
        exclude_list = kcalloc(devmax, sizeof(index), GFP_NOFS);
        if (!exclude_list)
                return -ENOMEM;

        /* we enter this fn pointing at the '=' */
        while (*s1 && *s1 != ' ' && *s1 != ',') {
                s1++;
                rc = server_name2index(s1, &index, &s2);
                if (rc < 0) {
                        CERROR("Can't parse server name '%s': rc = %d\n",
                               s1, rc);
                        break;
                }
                if (rc == LDD_F_SV_TYPE_OST)
                        exclude_list[lmd->lmd_exclude_count++] = index;
                else
                        CDEBUG(D_MOUNT, "ignoring exclude %.*s: type = %#x\n",
                               (uint)(s2 - s1), s1, rc);
                s1 = s2;
                /* now we are pointing at ':' (next exclude)
                 * or ',' (end of excludes)
                 */
                if (lmd->lmd_exclude_count >= devmax)
                        break;
        }
        if (rc >= 0) /* non-err */
                rc = 0;

        if (lmd->lmd_exclude_count) {
                /* permanent, freed in lustre_free_lsi */
                lmd->lmd_exclude = kcalloc(lmd->lmd_exclude_count,
                                           sizeof(index), GFP_NOFS);
                if (lmd->lmd_exclude) {
                        memcpy(lmd->lmd_exclude, exclude_list,
                               sizeof(index) * lmd->lmd_exclude_count);
                } else {
                        rc = -ENOMEM;
                        lmd->lmd_exclude_count = 0;
                }
        }
        kfree(exclude_list);
        return rc;
}

static int lmd_parse_mgssec(struct lustre_mount_data *lmd, char *ptr)
{
        char   *tail;
        int     length;

        kfree(lmd->lmd_mgssec);
        lmd->lmd_mgssec = NULL;

        tail = strchr(ptr, ',');
        if (!tail)
                length = strlen(ptr);
        else
                length = tail - ptr;

        lmd->lmd_mgssec = kzalloc(length + 1, GFP_NOFS);
        if (!lmd->lmd_mgssec)
                return -ENOMEM;

        memcpy(lmd->lmd_mgssec, ptr, length);
        lmd->lmd_mgssec[length] = '\0';
        return 0;
}

static int lmd_parse_string(char **handle, char *ptr)
{
        char   *tail;
        int     length;

        if (!handle || !ptr)
                return -EINVAL;

        kfree(*handle);
        *handle = NULL;

        tail = strchr(ptr, ',');
        if (!tail)
                length = strlen(ptr);
        else
                length = tail - ptr;

        *handle = kzalloc(length + 1, GFP_NOFS);
        if (!*handle)
                return -ENOMEM;

        memcpy(*handle, ptr, length);
        (*handle)[length] = '\0';

        return 0;
}

/* Collect multiple values for mgsnid specifiers */
static int lmd_parse_mgs(struct lustre_mount_data *lmd, char **ptr)
{
        lnet_nid_t nid;
        char *tail = *ptr;
        char *mgsnid;
        int   length;
        int   oldlen = 0;

        /* Find end of nidlist */
        while (class_parse_nid_quiet(tail, &nid, &tail) == 0)
                ;
        length = tail - *ptr;
        if (length == 0) {
                LCONSOLE_ERROR_MSG(0x159, "Can't parse NID '%s'\n", *ptr);
                return -EINVAL;
        }

        if (lmd->lmd_mgs)
                oldlen = strlen(lmd->lmd_mgs) + 1;

        mgsnid = kzalloc(oldlen + length + 1, GFP_NOFS);
        if (!mgsnid)
                return -ENOMEM;

        if (lmd->lmd_mgs) {
                /* Multiple mgsnid= are taken to mean failover locations */
                memcpy(mgsnid, lmd->lmd_mgs, oldlen);
                mgsnid[oldlen - 1] = ':';
                kfree(lmd->lmd_mgs);
        }
        memcpy(mgsnid + oldlen, *ptr, length);
        mgsnid[oldlen + length] = '\0';
        lmd->lmd_mgs = mgsnid;
        *ptr = tail;

        return 0;
}

/** Parse mount line options
 * e.g. mount -v -t lustre -o abort_recov uml1:uml2:/lustre-client /mnt/lustre
 * dev is passed as device=uml1:/lustre by mount.lustre
 */
static int lmd_parse(char *options, struct lustre_mount_data *lmd)
{
        char *s1, *s2, *devname = NULL;
        struct lustre_mount_data *raw = (struct lustre_mount_data *)options;
        int rc = 0;

        LASSERT(lmd);
        if (!options) {
                LCONSOLE_ERROR_MSG(0x162, "Missing mount data: check that /sbin/mount.lustre is installed.\n");
                return -EINVAL;
        }

        /* Options should be a string - try to detect old lmd data */
        if ((raw->lmd_magic & 0xffffff00) == (LMD_MAGIC & 0xffffff00)) {
                LCONSOLE_ERROR_MSG(0x163, "You're using an old version of /sbin/mount.lustre.  Please install version %s\n",
                                   LUSTRE_VERSION_STRING);
                return -EINVAL;
        }
        lmd->lmd_magic = LMD_MAGIC;

        lmd->lmd_params = kzalloc(LMD_PARAMS_MAXLEN, GFP_NOFS);
        if (!lmd->lmd_params)
                return -ENOMEM;
        lmd->lmd_params[0] = '\0';

        /* Set default flags here */

        s1 = options;
        while (*s1) {
                int clear = 0;
                int time_min = OBD_RECOVERY_TIME_MIN;
                char *s3;

                /* Skip whitespace and extra commas */
                while (*s1 == ' ' || *s1 == ',')
                        s1++;
                s3 = s1;

                /* Client options are parsed in ll_options: eg. flock,
                 * user_xattr, acl
                 */

                /* Parse non-ldiskfs options here. Rather than modifying
                 * ldiskfs, we just zero these out here
                 */
                if (strncmp(s1, "abort_recov", 11) == 0) {
                        lmd->lmd_flags |= LMD_FLG_ABORT_RECOV;
                        clear++;
                } else if (strncmp(s1, "recovery_time_soft=", 19) == 0) {
                        lmd->lmd_recovery_time_soft = max_t(int,
                                simple_strtoul(s1 + 19, NULL, 10), time_min);
                        clear++;
                } else if (strncmp(s1, "recovery_time_hard=", 19) == 0) {
                        lmd->lmd_recovery_time_hard = max_t(int,
                                simple_strtoul(s1 + 19, NULL, 10), time_min);
                        clear++;
                } else if (strncmp(s1, "noir", 4) == 0) {
                        lmd->lmd_flags |= LMD_FLG_NOIR; /* test purpose only. */
                        clear++;
                } else if (strncmp(s1, "nosvc", 5) == 0) {
                        lmd->lmd_flags |= LMD_FLG_NOSVC;
                        clear++;
                } else if (strncmp(s1, "nomgs", 5) == 0) {
                        lmd->lmd_flags |= LMD_FLG_NOMGS;
                        clear++;
                } else if (strncmp(s1, "noscrub", 7) == 0) {
                        lmd->lmd_flags |= LMD_FLG_NOSCRUB;
                        clear++;
                } else if (strncmp(s1, PARAM_MGSNODE,
                                   sizeof(PARAM_MGSNODE) - 1) == 0) {
                        s2 = s1 + sizeof(PARAM_MGSNODE) - 1;
                        /* Assume the next mount opt is the first
                         * invalid nid we get to.
                         */
                        rc = lmd_parse_mgs(lmd, &s2);
                        if (rc)
                                goto invalid;
                        clear++;
                } else if (strncmp(s1, "writeconf", 9) == 0) {
                        lmd->lmd_flags |= LMD_FLG_WRITECONF;
                        clear++;
                } else if (strncmp(s1, "update", 6) == 0) {
                        lmd->lmd_flags |= LMD_FLG_UPDATE;
                        clear++;
                } else if (strncmp(s1, "virgin", 6) == 0) {
                        lmd->lmd_flags |= LMD_FLG_VIRGIN;
                        clear++;
                } else if (strncmp(s1, "noprimnode", 10) == 0) {
                        lmd->lmd_flags |= LMD_FLG_NO_PRIMNODE;
                        clear++;
                } else if (strncmp(s1, "mgssec=", 7) == 0) {
                        rc = lmd_parse_mgssec(lmd, s1 + 7);
                        if (rc)
                                goto invalid;
                        s3 = s2;
                        clear++;
                /* ost exclusion list */
                } else if (strncmp(s1, "exclude=", 8) == 0) {
                        rc = lmd_make_exclusion(lmd, s1 + 7);
                        if (rc)
                                goto invalid;
                        clear++;
                } else if (strncmp(s1, "mgs", 3) == 0) {
                        /* We are an MGS */
                        lmd->lmd_flags |= LMD_FLG_MGS;
                        clear++;

                } else if (strncmp(s1, "svname=", 7) == 0) {
                        rc = lmd_parse_string(&lmd->lmd_profile, s1 + 7);
                        if (rc)
                                goto invalid;
                        clear++;
                } else if (strncmp(s1, "param=", 6) == 0) {
                        size_t length, params_length;
                        char *tail = strchr(s1 + 6, ',');

                        if (!tail) {
                                length = strlen(s1);
                        } else {
                                lnet_nid_t nid;
                                char *param_str = tail + 1;
                                int supplementary = 1;

                                while (!class_parse_nid_quiet(param_str, &nid,
                                                              &param_str)) {
                                        supplementary = 0;
                                }
                                length = param_str - s1 - supplementary;
                        }
                        length -= 6;
                        params_length = strlen(lmd->lmd_params);
                        if (params_length + length + 1 >= LMD_PARAMS_MAXLEN)
                                return -E2BIG;
                        strncat(lmd->lmd_params, s1 + 6, length);
                        lmd->lmd_params[params_length + length] = '\0';
                        strlcat(lmd->lmd_params, " ", LMD_PARAMS_MAXLEN);
                        s3 = s1 + 6 + length;
                        clear++;
                } else if (strncmp(s1, "osd=", 4) == 0) {
                        rc = lmd_parse_string(&lmd->lmd_osd_type, s1 + 4);
                        if (rc)
                                goto invalid;
                        clear++;
                }
                /* Linux 2.4 doesn't pass the device, so we stuck it at the
                 * end of the options.
                 */
                else if (strncmp(s1, "device=", 7) == 0) {
                        devname = s1 + 7;
                        /* terminate options right before device.  device
                         * must be the last one.
                         */
                        *s1 = '\0';
                        break;
                }

                /* Find next opt */
                s2 = strchr(s1, ',');
                if (!s2) {
                        if (clear)
                                *s1 = '\0';
                        break;
                }
                s2++;
                if (clear)
                        memmove(s1, s2, strlen(s2) + 1);
                else
                        s1 = s2;
        }

        if (!devname) {
                LCONSOLE_ERROR_MSG(0x164, "Can't find the device name (need mount option 'device=...')\n");
                goto invalid;
        }

        s1 = strstr(devname, ":/");
        if (s1) {
                ++s1;
                lmd->lmd_flags |= LMD_FLG_CLIENT;
                /* Remove leading /s from fsname */
                while (*++s1 == '/')
                        ;
                /* Freed in lustre_free_lsi */
                lmd->lmd_profile = kasprintf(GFP_NOFS, "%s-client", s1);
                if (!lmd->lmd_profile)
                        return -ENOMEM;
        }

        /* Freed in lustre_free_lsi */
        lmd->lmd_dev = kzalloc(strlen(devname) + 1, GFP_NOFS);
        if (!lmd->lmd_dev)
                return -ENOMEM;
        strcpy(lmd->lmd_dev, devname);

        /* Save mount options */
        s1 = options + strlen(options) - 1;
        while (s1 >= options && (*s1 == ',' || *s1 == ' '))
                *s1-- = 0;
        if (*options != 0) {
                /* Freed in lustre_free_lsi */
                lmd->lmd_opts = kzalloc(strlen(options) + 1, GFP_NOFS);
                if (!lmd->lmd_opts)
                        return -ENOMEM;
                strcpy(lmd->lmd_opts, options);
        }

        lmd_print(lmd);
        lmd->lmd_magic = LMD_MAGIC;

        return rc;

invalid:
        CERROR("Bad mount options %s\n", options);
        return -EINVAL;
}

/** This is the entry point for the mount call into Lustre.
 * This is called when a server or client is mounted,
 * and this is where we start setting things up.
 * @param data Mount options (e.g. -o flock,abort_recov)
 */
static int lustre_fill_super(struct super_block *sb, void *lmd2_data, int silent)
{
        struct lustre_mount_data *lmd;
        struct lustre_sb_info *lsi;
        int rc;

        CDEBUG(D_MOUNT | D_VFSTRACE, "VFS Op: sb %p\n", sb);

        lsi = lustre_init_lsi(sb);
        if (!lsi)
                return -ENOMEM;
        lmd = lsi->lsi_lmd;

        /*
         * Disable lockdep during mount, because mount locking patterns are
         * `special'.
         */
        lockdep_off();

        /*
         * LU-639: the obd cleanup of last mount may not finish yet, wait here.
         */
        obd_zombie_barrier();

        /* Figure out the lmd from the mount options */
        if (lmd_parse(lmd2_data, lmd)) {
                lustre_put_lsi(sb);
                rc = -EINVAL;
                goto out;
        }

        if (lmd_is_client(lmd)) {
                bool have_client = false;
                CDEBUG(D_MOUNT, "Mounting client %s\n", lmd->lmd_profile);
                if (!client_fill_super)
                        request_module("lustre");
                spin_lock(&client_lock);
                if (client_fill_super && try_module_get(client_mod))
                        have_client = true;
                spin_unlock(&client_lock);
                if (!have_client) {
                        LCONSOLE_ERROR_MSG(0x165, "Nothing registered for client mount! Is the 'lustre' module loaded?\n");
                        lustre_put_lsi(sb);
                        rc = -ENODEV;
                } else {
                        rc = lustre_start_mgc(sb);
                        if (rc) {
                                lustre_common_put_super(sb);
                                goto out;
                        }
                        /* Connect and start */
                        /* (should always be ll_fill_super) */
                        rc = (*client_fill_super)(sb);
                        /* c_f_s will call lustre_common_put_super on failure, otherwise
                         * c_f_s will have taken another reference to the module */
                        module_put(client_mod);
                }
        } else {
                CERROR("This is client-side-only module, cannot handle server mount.\n");
                rc = -EINVAL;
        }

        /* If error happens in fill_super() call, @lsi will be killed there.
         * This is why we do not put it here.
         */
        goto out;
out:
        if (rc) {
                CERROR("Unable to mount %s (%d)\n",
                       s2lsi(sb) ? lmd->lmd_dev : "", rc);
        } else {
                CDEBUG(D_SUPER, "Mount %s complete\n",
                       lmd->lmd_dev);
        }
        lockdep_on();
        return rc;
}

/* We can't call ll_fill_super by name because it lives in a module that
 * must be loaded after this one.
 */
void lustre_register_super_ops(struct module *mod,
                               int (*cfs)(struct super_block *sb),
                               void (*ksc)(struct super_block *sb))
{
        spin_lock(&client_lock);
        client_mod = mod;
        client_fill_super = cfs;
        kill_super_cb = ksc;
        spin_unlock(&client_lock);
}
EXPORT_SYMBOL(lustre_register_super_ops);

/***************** FS registration ******************/
static struct dentry *lustre_mount(struct file_system_type *fs_type, int flags,
                                   const char *devname, void *data)
{
        return mount_nodev(fs_type, flags, data, lustre_fill_super);
}

static void lustre_kill_super(struct super_block *sb)
{
        struct lustre_sb_info *lsi = s2lsi(sb);

        if (kill_super_cb && lsi)
                (*kill_super_cb)(sb);

        kill_anon_super(sb);
}

/** Register the "lustre" fs type
 */
static struct file_system_type lustre_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "lustre",
        .mount          = lustre_mount,
        .kill_sb        = lustre_kill_super,
        .fs_flags       = FS_RENAME_DOES_D_MOVE,
};
MODULE_ALIAS_FS("lustre");

int lustre_register_fs(void)
{
        return register_filesystem(&lustre_fs_type);
}

int lustre_unregister_fs(void)
{
        return unregister_filesystem(&lustre_fs_type);
}