// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/kthread.h>
#include <linux/crc32.h>
#include <linux/gfs2_ondisk.h>
#include <linux/delay.h>
#include <linux/uaccess.h>

#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "glops.h"
#include "log.h"
#include "lops.h"
#include "recovery.h"
#include "rgrp.h"
#include "super.h"
#include "util.h"

struct kmem_cache *gfs2_glock_cachep __read_mostly;
struct kmem_cache *gfs2_glock_aspace_cachep __read_mostly;
struct kmem_cache *gfs2_inode_cachep __read_mostly;
struct kmem_cache *gfs2_bufdata_cachep __read_mostly;
struct kmem_cache *gfs2_rgrpd_cachep __read_mostly;
struct kmem_cache *gfs2_quotad_cachep __read_mostly;
struct kmem_cache *gfs2_qadata_cachep __read_mostly;
struct kmem_cache *gfs2_trans_cachep __read_mostly;
mempool_t *gfs2_page_pool __read_mostly;

void gfs2_assert_i(struct gfs2_sbd *sdp)
{
        fs_emerg(sdp, "fatal assertion failed\n");
}

/**
 * check_journal_clean - Make sure a journal is clean for a spectator mount
 * @sdp: The GFS2 superblock
 * @jd: The journal descriptor
 * @verbose: Show more prints in the log
 *
 * Returns: 0 if the journal is clean or locked, else an error
 */
int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
                        bool verbose)
{
        int error;
        struct gfs2_holder j_gh;
        struct gfs2_log_header_host head;
        struct gfs2_inode *ip;

        ip = GFS2_I(jd->jd_inode);
        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_RECOVER |
                                   GL_EXACT | GL_NOCACHE, &j_gh);
        if (error) {
                if (verbose)
                        fs_err(sdp, "Error %d locking journal for spectator "
                               "mount.\n", error);
                return -EPERM;
        }
        error = gfs2_jdesc_check(jd);
        if (error) {
                if (verbose)
                        fs_err(sdp, "Error checking journal for spectator "
                               "mount.\n");
                goto out_unlock;
        }
        error = gfs2_find_jhead(jd, &head);
        if (error) {
                if (verbose)
                        fs_err(sdp, "Error parsing journal for spectator "
                               "mount.\n");
                goto out_unlock;
        }
        if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
                error = -EPERM;
                if (verbose)
                        fs_err(sdp, "jid=%u: Journal is dirty, so the first "
                               "mounter must not be a spectator.\n",
                               jd->jd_jid);
        }

out_unlock:
        gfs2_glock_dq_uninit(&j_gh);
        return error;
}

/**
 * gfs2_freeze_lock_shared - hold the freeze glock
 * @sdp: the superblock
 */
int gfs2_freeze_lock_shared(struct gfs2_sbd *sdp)
{
        int flags = LM_FLAG_RECOVER | GL_EXACT;
        int error;

        error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, flags,
                                   &sdp->sd_freeze_gh);
        if (error && error != GLR_TRYFAILED)
                fs_err(sdp, "can't lock the freeze glock: %d\n", error);
        return error;
}

void gfs2_freeze_unlock(struct gfs2_sbd *sdp)
{
        if (gfs2_holder_initialized(&sdp->sd_freeze_gh))
                gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
}

static void do_withdraw(struct gfs2_sbd *sdp)
{
        down_write(&sdp->sd_log_flush_lock);
        if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
                up_write(&sdp->sd_log_flush_lock);
                return;
        }
        clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
        up_write(&sdp->sd_log_flush_lock);

        gfs2_ail_drain(sdp); /* frees all transactions */

        wake_up(&sdp->sd_logd_waitq);
        wake_up(&sdp->sd_quota_wait);

        wait_event_timeout(sdp->sd_log_waitq,
                           gfs2_log_is_empty(sdp),
                           HZ * 5);

        sdp->sd_vfs->s_flags |= SB_RDONLY;

        /*
         * Dequeue any pending non-system glock holders that can no
         * longer be granted because the file system is withdrawn.
         */
        gfs2_withdraw_glocks(sdp);
}

void gfs2_lm(struct gfs2_sbd *sdp, const char *fmt, ...)
{
        struct va_format vaf;
        va_list args;

        if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW &&
            test_bit(SDF_WITHDRAWN, &sdp->sd_flags))
                return;

        va_start(args, fmt);
        vaf.fmt = fmt;
        vaf.va = &args;
        fs_err(sdp, "%pV", &vaf);
        va_end(args);
}

/**
 * gfs2_offline_uevent - run gfs2_withdraw_helper
 * @sdp: The GFS2 superblock
 */
static bool gfs2_offline_uevent(struct gfs2_sbd *sdp)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        long timeout;

        /* Skip protocol "lock_nolock" which doesn't require shared storage. */
        if (!ls->ls_ops->lm_lock)
                return false;

        /*
         * The gfs2_withdraw_helper replies by writing one of the following
         * status codes to "/sys$DEVPATH/lock_module/withdraw":
         *
         * 0 - The shared block device has been marked inactive.  Future write
         *     operations will fail.
         *
         * 1 - The shared block device may still be active and carry out
         *     write operations.
         *
         * If the "offline" uevent isn't reacted upon in time, the event
         * handler is assumed to have failed.
         */

        sdp->sd_withdraw_helper_status = -1;
        kobject_uevent(&sdp->sd_kobj, KOBJ_OFFLINE);
        timeout = gfs2_tune_get(sdp, gt_withdraw_helper_timeout) * HZ;
        wait_for_completion_timeout(&sdp->sd_withdraw_helper, timeout);
        if (sdp->sd_withdraw_helper_status == -1) {
                fs_err(sdp, "%s timed out\n", "gfs2_withdraw_helper");
        } else {
                fs_err(sdp, "%s %s with status %d\n",
                       "gfs2_withdraw_helper",
                       sdp->sd_withdraw_helper_status == 0 ?
                       "succeeded" : "failed",
                       sdp->sd_withdraw_helper_status);
        }
        return sdp->sd_withdraw_helper_status == 0;
}

void gfs2_withdraw_func(struct work_struct *work)
{
        struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_withdraw_work);
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        const struct lm_lockops *lm = ls->ls_ops;
        bool device_inactive;

        if (test_bit(SDF_KILL, &sdp->sd_flags))
                return;

        BUG_ON(sdp->sd_args.ar_debug);

        /*
         * Try to deactivate the shared block device so that no more I/O will
         * go through.  If successful, we can immediately trigger remote
         * recovery.  Otherwise, we must first empty out all our local caches.
         */

        device_inactive = gfs2_offline_uevent(sdp);

        if (sdp->sd_args.ar_errors == GFS2_ERRORS_DEACTIVATE && !device_inactive)
                panic("GFS2: fsid=%s: panic requested\n", sdp->sd_fsname);

        if (lm->lm_unmount) {
                if (device_inactive) {
                        lm->lm_unmount(sdp, false);
                        do_withdraw(sdp);
                } else {
                        do_withdraw(sdp);
                        lm->lm_unmount(sdp, false);
                }
        } else {
                do_withdraw(sdp);
        }

        fs_err(sdp, "file system withdrawn\n");
}

void gfs2_withdraw(struct gfs2_sbd *sdp)
{
        if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW ||
            sdp->sd_args.ar_errors == GFS2_ERRORS_DEACTIVATE) {
                if (test_and_set_bit(SDF_WITHDRAWN, &sdp->sd_flags))
                        return;

                dump_stack();
                /*
                 * There is no need to withdraw when the superblock hasn't been
                 * fully initialized, yet.
                 */
                if (!(sdp->sd_vfs->s_flags & SB_BORN))
                        return;
                fs_err(sdp, "about to withdraw this file system\n");
                schedule_work(&sdp->sd_withdraw_work);
                return;
        }

        if (sdp->sd_args.ar_errors == GFS2_ERRORS_PANIC)
                panic("GFS2: fsid=%s: panic requested\n", sdp->sd_fsname);
}

/*
 * gfs2_assert_withdraw_i - Cause the machine to withdraw if @assertion is false
 */

void gfs2_assert_withdraw_i(struct gfs2_sbd *sdp, char *assertion,
                            const char *function, char *file, unsigned int line)
{
        if (gfs2_withdrawn(sdp))
                return;

        fs_err(sdp,
               "fatal: assertion \"%s\" failed - "
               "function = %s, file = %s, line = %u\n",
               assertion, function, file, line);

        gfs2_withdraw(sdp);
        dump_stack();
}

/*
 * gfs2_assert_warn_i - Print a message to the console if @assertion is false
 */

void gfs2_assert_warn_i(struct gfs2_sbd *sdp, char *assertion,
                        const char *function, char *file, unsigned int line)
{
        if (time_before(jiffies,
                        sdp->sd_last_warning +
                        gfs2_tune_get(sdp, gt_complain_secs) * HZ))
                return;

        if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW)
                fs_warn(sdp, "warning: assertion \"%s\" failed - "
                        "function = %s, file = %s, line = %u\n",
                        assertion, function, file, line);

        if (sdp->sd_args.ar_debug)
                BUG();
        else
                dump_stack();

        if (sdp->sd_args.ar_errors == GFS2_ERRORS_PANIC)
                panic("GFS2: fsid=%s: warning: assertion \"%s\" failed - "
                      "function = %s, file = %s, line = %u\n",
                      sdp->sd_fsname, assertion,
                      function, file, line);

        sdp->sd_last_warning = jiffies;
}

/*
 * gfs2_consist_i - Flag a filesystem consistency error and withdraw
 */

void gfs2_consist_i(struct gfs2_sbd *sdp, const char *function,
                    char *file, unsigned int line)
{
        gfs2_lm(sdp,
                "fatal: filesystem consistency error - "
                "function = %s, file = %s, line = %u\n",
                function, file, line);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_consist_inode_i - Flag an inode consistency error and withdraw
 */

void gfs2_consist_inode_i(struct gfs2_inode *ip,
                          const char *function, char *file, unsigned int line)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

        gfs2_lm(sdp,
                "fatal: filesystem consistency error - "
                "inode = %llu %llu, "
                "function = %s, file = %s, line = %u\n",
                (unsigned long long)ip->i_no_formal_ino,
                (unsigned long long)ip->i_no_addr,
                function, file, line);
        gfs2_dump_glock(NULL, ip->i_gl, 1);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_consist_rgrpd_i - Flag a RG consistency error and withdraw
 */

void gfs2_consist_rgrpd_i(struct gfs2_rgrpd *rgd,
                          const char *function, char *file, unsigned int line)
{
        struct gfs2_sbd *sdp = rgd->rd_sbd;
        char fs_id_buf[sizeof(sdp->sd_fsname) + 7];

        sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
        gfs2_rgrp_dump(NULL, rgd, fs_id_buf);
        gfs2_lm(sdp,
                "fatal: filesystem consistency error - "
                "RG = %llu, "
                "function = %s, file = %s, line = %u\n",
                (unsigned long long)rgd->rd_addr,
                function, file, line);
        gfs2_dump_glock(NULL, rgd->rd_gl, 1);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_meta_check_ii - Flag a magic number consistency error and withdraw
 */

void gfs2_meta_check_ii(struct gfs2_sbd *sdp, struct buffer_head *bh,
                        const char *function, char *file,
                        unsigned int line)
{
        gfs2_lm(sdp,
                "fatal: invalid metadata block - "
                "bh = %llu (bad magic number), "
                "function = %s, file = %s, line = %u\n",
                (unsigned long long)bh->b_blocknr,
                function, file, line);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_metatype_check_ii - Flag a metadata type consistency error and withdraw
 */

void gfs2_metatype_check_ii(struct gfs2_sbd *sdp, struct buffer_head *bh,
                            u16 type, u16 t, const char *function,
                            char *file, unsigned int line)
{
        gfs2_lm(sdp,
                "fatal: invalid metadata block - "
                "bh = %llu (type: exp=%u, found=%u), "
                "function = %s, file = %s, line = %u\n",
                (unsigned long long)bh->b_blocknr, type, t,
                function, file, line);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_io_error_i - Flag an I/O error and withdraw
 * Returns: -1 if this call withdrew the machine,
 *          0 if it was already withdrawn
 */

void gfs2_io_error_i(struct gfs2_sbd *sdp, const char *function, char *file,
                     unsigned int line)
{
        gfs2_lm(sdp,
                "fatal: I/O error - "
                "function = %s, file = %s, line = %u\n",
                function, file, line);
        gfs2_withdraw(sdp);
}

/*
 * gfs2_io_error_bh_i - Flag a buffer I/O error and withdraw
 */

void gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,
                        const char *function, char *file, unsigned int line)
{
        if (gfs2_withdrawn(sdp))
                return;

        fs_err(sdp, "fatal: I/O error - "
               "block = %llu, "
               "function = %s, file = %s, line = %u\n",
               (unsigned long long)bh->b_blocknr, function, file, line);
        gfs2_withdraw(sdp);
}