ops_fstype.c

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/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/kthread.h>
#include <linux/export.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/gfs2_ondisk.h>
#include <linux/quotaops.h>
#include <linux/lockdep.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "recovery.h"
#include "rgrp.h"
#include "super.h"
#include "sys.h"
#include "util.h"
#include "log.h"
#include "quota.h"
#include "dir.h"
#include "trace_gfs2.h"

#define DO 0
#define UNDO 1

static void gfs2_tune_init(struct gfs2_tune *gt)
{
    spin_lock_init(&gt->gt_spin);

    gt->gt_quota_simul_sync = 64;
    gt->gt_quota_warn_period = 10;
    gt->gt_quota_scale_num = 1;
    gt->gt_quota_scale_den = 1;
    gt->gt_new_files_jdata = 0;
    gt->gt_max_readahead = 1 << 18;
    gt->gt_complain_secs = 10;
}

static struct gfs2_sbd *init_sbd(struct super_block *sb)
{
    struct gfs2_sbd *sdp;

    sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
    if (!sdp)
        return NULL;

    sb->s_fs_info = sdp;
    sdp->sd_vfs = sb;
    sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
    if (!sdp->sd_lkstats) {
        kfree(sdp);
        return NULL;
    }

    set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
    gfs2_tune_init(&sdp->sd_tune);

    init_waitqueue_head(&sdp->sd_glock_wait);
    atomic_set(&sdp->sd_glock_disposal, 0);
    init_completion(&sdp->sd_locking_init);
    spin_lock_init(&sdp->sd_statfs_spin);

    spin_lock_init(&sdp->sd_rindex_spin);
    sdp->sd_rindex_tree.rb_node = NULL;

    INIT_LIST_HEAD(&sdp->sd_jindex_list);
    spin_lock_init(&sdp->sd_jindex_spin);
    mutex_init(&sdp->sd_jindex_mutex);

    INIT_LIST_HEAD(&sdp->sd_quota_list);
    mutex_init(&sdp->sd_quota_mutex);
    init_waitqueue_head(&sdp->sd_quota_wait);
    INIT_LIST_HEAD(&sdp->sd_trunc_list);
    spin_lock_init(&sdp->sd_trunc_lock);

    spin_lock_init(&sdp->sd_log_lock);
    atomic_set(&sdp->sd_log_pinned, 0);
    INIT_LIST_HEAD(&sdp->sd_log_le_buf);
    INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
    INIT_LIST_HEAD(&sdp->sd_log_le_databuf);
    INIT_LIST_HEAD(&sdp->sd_log_le_ordered);

    init_waitqueue_head(&sdp->sd_log_waitq);
    init_waitqueue_head(&sdp->sd_logd_waitq);
    spin_lock_init(&sdp->sd_ail_lock);
    INIT_LIST_HEAD(&sdp->sd_ail1_list);
    INIT_LIST_HEAD(&sdp->sd_ail2_list);

    init_rwsem(&sdp->sd_log_flush_lock);
    atomic_set(&sdp->sd_log_in_flight, 0);
    init_waitqueue_head(&sdp->sd_log_flush_wait);

    INIT_LIST_HEAD(&sdp->sd_revoke_list);

    mutex_init(&sdp->sd_freeze_lock);

    return sdp;
}


static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
{
    struct gfs2_sb_host *sb = &sdp->sd_sb;

    if (sb->sb_magic != GFS2_MAGIC ||
        sb->sb_type != GFS2_METATYPE_SB) {
        if (!silent)
            printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
        return -EINVAL;
    }

    /*  If format numbers match exactly, we're done.  */

    if (sb->sb_fs_format == GFS2_FORMAT_FS &&
        sb->sb_multihost_format == GFS2_FORMAT_MULTI)
        return 0;

    fs_warn(sdp, "Unknown on-disk format, unable to mount\n");

    return -EINVAL;
}

static void end_bio_io_page(struct bio *bio, int error)
{
    struct page *page = bio->bi_private;

    if (!error)
        SetPageUptodate(page);
    else
        printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
    unlock_page(page);
}

static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
{
    struct gfs2_sb_host *sb = &sdp->sd_sb;
    struct super_block *s = sdp->sd_vfs;
    const struct gfs2_sb *str = buf;

    sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
    sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
    sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
    sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
    sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
    sb->sb_bsize = be32_to_cpu(str->sb_bsize);
    sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
    sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
    sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
    sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
    sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);

    memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
    memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
    memcpy(s->s_uuid, str->sb_uuid, 16);
}

static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
{
    struct super_block *sb = sdp->sd_vfs;
    struct gfs2_sb *p;
    struct page *page;
    struct bio *bio;

    page = alloc_page(GFP_NOFS);
    if (unlikely(!page))
        return -ENOBUFS;

    ClearPageUptodate(page);
    ClearPageDirty(page);
    lock_page(page);

    bio = bio_alloc(GFP_NOFS, 1);
    bio->bi_sector = sector * (sb->s_blocksize >> 9);
    bio->bi_bdev = sb->s_bdev;
    bio_add_page(bio, page, PAGE_SIZE, 0);

    bio->bi_end_io = end_bio_io_page;
    bio->bi_private = page;
    submit_bio(READ_SYNC | REQ_META, bio);
    wait_on_page_locked(page);
    bio_put(bio);
    if (!PageUptodate(page)) {
        __free_page(page);
        return -EIO;
    }
    p = kmap(page);
    gfs2_sb_in(sdp, p);
    kunmap(page);
    __free_page(page);
    return gfs2_check_sb(sdp, silent);
}

static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
{
    u32 hash_blocks, ind_blocks, leaf_blocks;
    u32 tmp_blocks;
    unsigned int x;
    int error;

    error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
    if (error) {
        if (!silent)
            fs_err(sdp, "can't read superblock\n");
        return error;
    }

    sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
                   GFS2_BASIC_BLOCK_SHIFT;
    sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
    sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
              sizeof(struct gfs2_dinode)) / sizeof(u64);
    sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
              sizeof(struct gfs2_meta_header)) / sizeof(u64);
    sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
    sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
    sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
    sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
    sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
                sizeof(struct gfs2_meta_header)) /
                    sizeof(struct gfs2_quota_change);

    /* Compute maximum reservation required to add a entry to a directory */

    hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
                 sdp->sd_jbsize);

    ind_blocks = 0;
    for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
        tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
        ind_blocks += tmp_blocks;
    }

    leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;

    sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;

    sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
                sizeof(struct gfs2_dinode);
    sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
    for (x = 2;; x++) {
        u64 space, d;
        u32 m;

        space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
        d = space;
        m = do_div(d, sdp->sd_inptrs);

        if (d != sdp->sd_heightsize[x - 1] || m)
            break;
        sdp->sd_heightsize[x] = space;
    }
    sdp->sd_max_height = x;
    sdp->sd_heightsize[x] = ~0;
    gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);

    sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
                 sizeof(struct gfs2_dinode);
    sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
    for (x = 2;; x++) {
        u64 space, d;
        u32 m;

        space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
        d = space;
        m = do_div(d, sdp->sd_inptrs);

        if (d != sdp->sd_jheightsize[x - 1] || m)
            break;
        sdp->sd_jheightsize[x] = space;
    }
    sdp->sd_max_jheight = x;
    sdp->sd_jheightsize[x] = ~0;
    gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);

    return 0;
}

static int init_names(struct gfs2_sbd *sdp, int silent)
{
    char *proto, *table;
    int error = 0;

    proto = sdp->sd_args.ar_lockproto;
    table = sdp->sd_args.ar_locktable;

    /*  Try to autodetect  */

    if (!proto[0] || !table[0]) {
        error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
        if (error)
            return error;

        if (!proto[0])
            proto = sdp->sd_sb.sb_lockproto;
        if (!table[0])
            table = sdp->sd_sb.sb_locktable;
    }

    if (!table[0])
        table = sdp->sd_vfs->s_id;

    strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
    strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);

    table = sdp->sd_table_name;
    while ((table = strchr(table, '/')))
        *table = '_';

    return error;
}

static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
            int undo)
{
    int error = 0;

    if (undo)
        goto fail_trans;

    error = gfs2_glock_nq_num(sdp,
                  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
                  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
                  mount_gh);
    if (error) {
        fs_err(sdp, "can't acquire mount glock: %d\n", error);
        goto fail;
    }

    error = gfs2_glock_nq_num(sdp,
                  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
                  LM_ST_SHARED,
                  LM_FLAG_NOEXP | GL_EXACT,
                  &sdp->sd_live_gh);
    if (error) {
        fs_err(sdp, "can't acquire live glock: %d\n", error);
        goto fail_mount;
    }

    error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
                   CREATE, &sdp->sd_rename_gl);
    if (error) {
        fs_err(sdp, "can't create rename glock: %d\n", error);
        goto fail_live;
    }

    error = gfs2_glock_get(sdp, GFS2_TRANS_LOCK, &gfs2_trans_glops,
                   CREATE, &sdp->sd_trans_gl);
    if (error) {
        fs_err(sdp, "can't create transaction glock: %d\n", error);
        goto fail_rename;
    }

    return 0;

fail_trans:
    gfs2_glock_put(sdp->sd_trans_gl);
fail_rename:
    gfs2_glock_put(sdp->sd_rename_gl);
fail_live:
    gfs2_glock_dq_uninit(&sdp->sd_live_gh);
fail_mount:
    gfs2_glock_dq_uninit(mount_gh);
fail:
    return error;
}

static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
                u64 no_addr, const char *name)
{
    struct gfs2_sbd *sdp = sb->s_fs_info;
    struct dentry *dentry;
    struct inode *inode;

    inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
    if (IS_ERR(inode)) {
        fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
        return PTR_ERR(inode);
    }
    dentry = d_make_root(inode);
    if (!dentry) {
        fs_err(sdp, "can't alloc %s dentry\n", name);
        return -ENOMEM;
    }
    *dptr = dentry;
    return 0;
}

static int init_sb(struct gfs2_sbd *sdp, int silent)
{
    struct super_block *sb = sdp->sd_vfs;
    struct gfs2_holder sb_gh;
    u64 no_addr;
    int ret;

    ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
                LM_ST_SHARED, 0, &sb_gh);
    if (ret) {
        fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
        return ret;
    }

    ret = gfs2_read_sb(sdp, silent);
    if (ret) {
        fs_err(sdp, "can't read superblock: %d\n", ret);
        goto out;
    }

    /* Set up the buffer cache and SB for real */
    if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
        ret = -EINVAL;
        fs_err(sdp, "FS block size (%u) is too small for device "
               "block size (%u)\n",
               sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
        goto out;
    }
    if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
        ret = -EINVAL;
        fs_err(sdp, "FS block size (%u) is too big for machine "
               "page size (%u)\n",
               sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
        goto out;
    }
    sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);

    /* Get the root inode */
    no_addr = sdp->sd_sb.sb_root_dir.no_addr;
    ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
    if (ret)
        goto out;

    /* Get the master inode */
    no_addr = sdp->sd_sb.sb_master_dir.no_addr;
    ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
    if (ret) {
        dput(sdp->sd_root_dir);
        goto out;
    }
    sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
out:
    gfs2_glock_dq_uninit(&sb_gh);
    return ret;
}

static int map_journal_extents(struct gfs2_sbd *sdp)
{
    struct gfs2_jdesc *jd = sdp->sd_jdesc;
    unsigned int lb;
    u64 db, prev_db; /* logical block, disk block, prev disk block */
    struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
    struct gfs2_journal_extent *jext = NULL;
    struct buffer_head bh;
    int rc = 0;

    prev_db = 0;

    for (lb = 0; lb < i_size_read(jd->jd_inode) >> sdp->sd_sb.sb_bsize_shift; lb++) {
        bh.b_state = 0;
        bh.b_blocknr = 0;
        bh.b_size = 1 << ip->i_inode.i_blkbits;
        rc = gfs2_block_map(jd->jd_inode, lb, &bh, 0);
        db = bh.b_blocknr;
        if (rc || !db) {
            printk(KERN_INFO "GFS2 journal mapping error %d: lb="
                   "%u db=%llu\n", rc, lb, (unsigned long long)db);
            break;
        }
        if (!prev_db || db != prev_db + 1) {
            jext = kzalloc(sizeof(struct gfs2_journal_extent),
                       GFP_KERNEL);
            if (!jext) {
                printk(KERN_INFO "GFS2 error: out of memory "
                       "mapping journal extents.\n");
                rc = -ENOMEM;
                break;
            }
            jext->dblock = db;
            jext->lblock = lb;
            jext->blocks = 1;
            list_add_tail(&jext->extent_list, &jd->extent_list);
        } else {
            jext->blocks++;
        }
        prev_db = db;
    }
    return rc;
}

static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
{
    char *message = "FIRSTMOUNT=Done";
    char *envp[] = { message, NULL };

    fs_info(sdp, "first mount done, others may mount\n");

    if (sdp->sd_lockstruct.ls_ops->lm_first_done)
        sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);

    kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
}

static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
{
    struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
    struct qstr name;
    char buf[20];
    struct gfs2_jdesc *jd;
    int error;

    name.name = buf;

    mutex_lock(&sdp->sd_jindex_mutex);

    for (;;) {
        error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
        if (error)
            break;

        name.len = sprintf(buf, "journal%u", sdp->sd_journals);
        name.hash = gfs2_disk_hash(name.name, name.len);

        error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
        if (error == -ENOENT) {
            error = 0;
            break;
        }

        gfs2_glock_dq_uninit(ji_gh);

        if (error)
            break;

        error = -ENOMEM;
        jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
        if (!jd)
            break;

        INIT_LIST_HEAD(&jd->extent_list);
        INIT_WORK(&jd->jd_work, gfs2_recover_func);
        jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
        if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
            if (!jd->jd_inode)
                error = -ENOENT;
            else
                error = PTR_ERR(jd->jd_inode);
            kfree(jd);
            break;
        }

        spin_lock(&sdp->sd_jindex_spin);
        jd->jd_jid = sdp->sd_journals++;
        list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
        spin_unlock(&sdp->sd_jindex_spin);
    }

    mutex_unlock(&sdp->sd_jindex_mutex);

    return error;
}

static int init_journal(struct gfs2_sbd *sdp, int undo)
{
    struct inode *master = sdp->sd_master_dir->d_inode;
    struct gfs2_holder ji_gh;
    struct gfs2_inode *ip;
    int jindex = 1;
    int error = 0;

    if (undo) {
        jindex = 0;
        goto fail_jinode_gh;
    }

    sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
    if (IS_ERR(sdp->sd_jindex)) {
        fs_err(sdp, "can't lookup journal index: %d\n", error);
        return PTR_ERR(sdp->sd_jindex);
    }

    /* Load in the journal index special file */

    error = gfs2_jindex_hold(sdp, &ji_gh);
    if (error) {
        fs_err(sdp, "can't read journal index: %d\n", error);
        goto fail;
    }

    error = -EUSERS;
    if (!gfs2_jindex_size(sdp)) {
        fs_err(sdp, "no journals!\n");
        goto fail_jindex;
    }

    if (sdp->sd_args.ar_spectator) {
        sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
        atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
        atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
        atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
    } else {
        if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
            fs_err(sdp, "can't mount journal #%u\n",
                   sdp->sd_lockstruct.ls_jid);
            fs_err(sdp, "there are only %u journals (0 - %u)\n",
                   gfs2_jindex_size(sdp),
                   gfs2_jindex_size(sdp) - 1);
            goto fail_jindex;
        }
        sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);

        error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
                      &gfs2_journal_glops,
                      LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
                      &sdp->sd_journal_gh);
        if (error) {
            fs_err(sdp, "can't acquire journal glock: %d\n", error);
            goto fail_jindex;
        }

        ip = GFS2_I(sdp->sd_jdesc->jd_inode);
        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
                       LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
                       &sdp->sd_jinode_gh);
        if (error) {
            fs_err(sdp, "can't acquire journal inode glock: %d\n",
                   error);
            goto fail_journal_gh;
        }

        error = gfs2_jdesc_check(sdp->sd_jdesc);
        if (error) {
            fs_err(sdp, "my journal (%u) is bad: %d\n",
                   sdp->sd_jdesc->jd_jid, error);
            goto fail_jinode_gh;
        }
        atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
        atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
        atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);

        /* Map the extents for this journal's blocks */
        map_journal_extents(sdp);
    }
    trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));

    if (sdp->sd_lockstruct.ls_first) {
        unsigned int x;
        for (x = 0; x < sdp->sd_journals; x++) {
            error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
                             true);
            if (error) {
                fs_err(sdp, "error recovering journal %u: %d\n",
                       x, error);
                goto fail_jinode_gh;
            }
        }

        gfs2_others_may_mount(sdp);
    } else if (!sdp->sd_args.ar_spectator) {
        error = gfs2_recover_journal(sdp->sd_jdesc, true);
        if (error) {
            fs_err(sdp, "error recovering my journal: %d\n", error);
            goto fail_jinode_gh;
        }
    }

    set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
    gfs2_glock_dq_uninit(&ji_gh);
    jindex = 0;

    return 0;

fail_jinode_gh:
    if (!sdp->sd_args.ar_spectator)
        gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
fail_journal_gh:
    if (!sdp->sd_args.ar_spectator)
        gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
fail_jindex:
    gfs2_jindex_free(sdp);
    if (jindex)
        gfs2_glock_dq_uninit(&ji_gh);
fail:
    iput(sdp->sd_jindex);
    return error;
}

static struct lock_class_key gfs2_quota_imutex_key;

static int init_inodes(struct gfs2_sbd *sdp, int undo)
{
    int error = 0;
    struct inode *master = sdp->sd_master_dir->d_inode;

    if (undo)
        goto fail_qinode;

    error = init_journal(sdp, undo);
    if (error)
        goto fail;

    /* Read in the master statfs inode */
    sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
    if (IS_ERR(sdp->sd_statfs_inode)) {
        error = PTR_ERR(sdp->sd_statfs_inode);
        fs_err(sdp, "can't read in statfs inode: %d\n", error);
        goto fail_journal;
    }

    /* Read in the resource index inode */
    sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
    if (IS_ERR(sdp->sd_rindex)) {
        error = PTR_ERR(sdp->sd_rindex);
        fs_err(sdp, "can't get resource index inode: %d\n", error);
        goto fail_statfs;
    }
    sdp->sd_rindex_uptodate = 0;

    /* Read in the quota inode */
    sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
    if (IS_ERR(sdp->sd_quota_inode)) {
        error = PTR_ERR(sdp->sd_quota_inode);
        fs_err(sdp, "can't get quota file inode: %d\n", error);
        goto fail_rindex;
    }
    /*
     * i_mutex on quota files is special. Since this inode is hidden system
     * file, we are safe to define locking ourselves.
     */
    lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
              &gfs2_quota_imutex_key);

    error = gfs2_rindex_update(sdp);
    if (error)
        goto fail_qinode;

    return 0;

fail_qinode:
    iput(sdp->sd_quota_inode);
fail_rindex:
    gfs2_clear_rgrpd(sdp);
    iput(sdp->sd_rindex);
fail_statfs:
    iput(sdp->sd_statfs_inode);
fail_journal:
    init_journal(sdp, UNDO);
fail:
    return error;
}

static int init_per_node(struct gfs2_sbd *sdp, int undo)
{
    struct inode *pn = NULL;
    char buf[30];
    int error = 0;
    struct gfs2_inode *ip;
    struct inode *master = sdp->sd_master_dir->d_inode;

    if (sdp->sd_args.ar_spectator)
        return 0;

    if (undo)
        goto fail_qc_gh;

    pn = gfs2_lookup_simple(master, "per_node");
    if (IS_ERR(pn)) {
        error = PTR_ERR(pn);
        fs_err(sdp, "can't find per_node directory: %d\n", error);
        return error;
    }

    sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
    sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
    if (IS_ERR(sdp->sd_sc_inode)) {
        error = PTR_ERR(sdp->sd_sc_inode);
        fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
        goto fail;
    }

    sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
    sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
    if (IS_ERR(sdp->sd_qc_inode)) {
        error = PTR_ERR(sdp->sd_qc_inode);
        fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
        goto fail_ut_i;
    }

    iput(pn);
    pn = NULL;

    ip = GFS2_I(sdp->sd_sc_inode);
    error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
                   &sdp->sd_sc_gh);
    if (error) {
        fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
        goto fail_qc_i;
    }

    ip = GFS2_I(sdp->sd_qc_inode);
    error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
                   &sdp->sd_qc_gh);
    if (error) {
        fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
        goto fail_ut_gh;
    }

    return 0;

fail_qc_gh:
    gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
fail_ut_gh:
    gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
fail_qc_i:
    iput(sdp->sd_qc_inode);
fail_ut_i:
    iput(sdp->sd_sc_inode);
fail:
    if (pn)
        iput(pn);
    return error;
}

static int init_threads(struct gfs2_sbd *sdp, int undo)
{
    struct task_struct *p;
    int error = 0;

    if (undo)
        goto fail_quotad;

    p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
    error = IS_ERR(p);
    if (error) {
        fs_err(sdp, "can't start logd thread: %d\n", error);
        return error;
    }
    sdp->sd_logd_process = p;

    p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
    error = IS_ERR(p);
    if (error) {
        fs_err(sdp, "can't start quotad thread: %d\n", error);
        goto fail;
    }
    sdp->sd_quotad_process = p;

    return 0;


fail_quotad:
    kthread_stop(sdp->sd_quotad_process);
fail:
    kthread_stop(sdp->sd_logd_process);
    return error;
}

static const match_table_t nolock_tokens = {
    { Opt_jid, "jid=%d\n", },
    { Opt_err, NULL },
};

static const struct lm_lockops nolock_ops = {
    .lm_proto_name = "lock_nolock",
    .lm_put_lock = gfs2_glock_free,
    .lm_tokens = &nolock_tokens,
};

static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
{
    const struct lm_lockops *lm;
    struct lm_lockstruct *ls = &sdp->sd_lockstruct;
    struct gfs2_args *args = &sdp->sd_args;
    const char *proto = sdp->sd_proto_name;
    const char *table = sdp->sd_table_name;
    char *o, *options;
    int ret;

    if (!strcmp("lock_nolock", proto)) {
        lm = &nolock_ops;
        sdp->sd_args.ar_localflocks = 1;
#ifdef CONFIG_GFS2_FS_LOCKING_DLM
    } else if (!strcmp("lock_dlm", proto)) {
        lm = &gfs2_dlm_ops;
#endif
    } else {
        printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
        return -ENOENT;
    }

    fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);

    ls->ls_ops = lm;
    ls->ls_first = 1;

    for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
        substring_t tmp[MAX_OPT_ARGS];
        int token, option;

        if (!o || !*o)
            continue;

        token = match_token(o, *lm->lm_tokens, tmp);
        switch (token) {
        case Opt_jid:
            ret = match_int(&tmp[0], &option);
            if (ret || option < 0) 
                goto hostdata_error;
            if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
                ls->ls_jid = option;
            break;
        case Opt_id:
        case Opt_nodir:
            /* Obsolete, but left for backward compat purposes */
            break;
        case Opt_first:
            ret = match_int(&tmp[0], &option);
            if (ret || (option != 0 && option != 1))
                goto hostdata_error;
            ls->ls_first = option;
            break;
        case Opt_err:
        default:
hostdata_error:
            fs_info(sdp, "unknown hostdata (%s)\n", o);
            return -EINVAL;
        }
    }

    if (lm->lm_mount == NULL) {
        fs_info(sdp, "Now mounting FS...\n");
        complete_all(&sdp->sd_locking_init);
        return 0;
    }
    ret = lm->lm_mount(sdp, table);
    if (ret == 0)
        fs_info(sdp, "Joined cluster. Now mounting FS...\n");
    complete_all(&sdp->sd_locking_init);
    return ret;
}

void gfs2_lm_unmount(struct gfs2_sbd *sdp)
{
    const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
    if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
        lm->lm_unmount)
        lm->lm_unmount(sdp);
}

static int gfs2_journalid_wait(void *word)
{
    if (signal_pending(current))
        return -EINTR;
    schedule();
    return 0;
}

static int wait_on_journal(struct gfs2_sbd *sdp)
{
    if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
        return 0;

    return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
}

void gfs2_online_uevent(struct gfs2_sbd *sdp)
{
    struct super_block *sb = sdp->sd_vfs;
    char ro[20];
    char spectator[20];
    char *envp[] = { ro, spectator, NULL };
    sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
    sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
    kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
}

static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
{
    struct gfs2_sbd *sdp;
    struct gfs2_holder mount_gh;
    int error;

    sdp = init_sbd(sb);
    if (!sdp) {
        printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
        return -ENOMEM;
    }
    sdp->sd_args = *args;

    if (sdp->sd_args.ar_spectator) {
                sb->s_flags |= MS_RDONLY;
        set_bit(SDF_RORECOVERY, &sdp->sd_flags);
    }
    if (sdp->sd_args.ar_posix_acl)
        sb->s_flags |= MS_POSIXACL;
    if (sdp->sd_args.ar_nobarrier)
        set_bit(SDF_NOBARRIERS, &sdp->sd_flags);

    sb->s_flags |= MS_NOSEC;
    sb->s_magic = GFS2_MAGIC;
    sb->s_op = &gfs2_super_ops;
    sb->s_d_op = &gfs2_dops;
    sb->s_export_op = &gfs2_export_ops;
    sb->s_xattr = gfs2_xattr_handlers;
    sb->s_qcop = &gfs2_quotactl_ops;
    sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
    sb->s_time_gran = 1;
    sb->s_maxbytes = MAX_LFS_FILESIZE;

    /* Set up the buffer cache and fill in some fake block size values
       to allow us to read-in the on-disk superblock. */
    sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
    sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
    sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
                               GFS2_BASIC_BLOCK_SHIFT;
    sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;

    sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
    sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
    if (sdp->sd_args.ar_statfs_quantum) {
        sdp->sd_tune.gt_statfs_slow = 0;
        sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
    } else {
        sdp->sd_tune.gt_statfs_slow = 1;
        sdp->sd_tune.gt_statfs_quantum = 30;
    }

    error = init_names(sdp, silent);
    if (error) {
        /* In this case, we haven't initialized sysfs, so we have to
           manually free the sdp. */
        free_percpu(sdp->sd_lkstats);
        kfree(sdp);
        sb->s_fs_info = NULL;
        return error;
    }

    snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);

    error = gfs2_sys_fs_add(sdp);
    /*
     * If we hit an error here, gfs2_sys_fs_add will have called function
     * kobject_put which causes the sysfs usage count to go to zero, which
     * causes sysfs to call function gfs2_sbd_release, which frees sdp.
     * Subsequent error paths here will call gfs2_sys_fs_del, which also
     * kobject_put to free sdp.
     */
    if (error)
        return error;

    gfs2_create_debugfs_file(sdp);

    error = gfs2_lm_mount(sdp, silent);
    if (error)
        goto fail_debug;

    error = init_locking(sdp, &mount_gh, DO);
    if (error)
        goto fail_lm;

    error = init_sb(sdp, silent);
    if (error)
        goto fail_locking;

    error = wait_on_journal(sdp);
    if (error)
        goto fail_sb;

    /*
     * If user space has failed to join the cluster or some similar
     * failure has occurred, then the journal id will contain a
     * negative (error) number. This will then be returned to the
     * caller (of the mount syscall). We do this even for spectator
     * mounts (which just write a jid of 0 to indicate "ok" even though
     * the jid is unused in the spectator case)
     */
    if (sdp->sd_lockstruct.ls_jid < 0) {
        error = sdp->sd_lockstruct.ls_jid;
        sdp->sd_lockstruct.ls_jid = 0;
        goto fail_sb;
    }

    if (sdp->sd_args.ar_spectator)
        snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
             sdp->sd_table_name);
    else
        snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
             sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);

    error = init_inodes(sdp, DO);
    if (error)
        goto fail_sb;

    error = init_per_node(sdp, DO);
    if (error)
        goto fail_inodes;

    error = gfs2_statfs_init(sdp);
    if (error) {
        fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
        goto fail_per_node;
    }

    error = init_threads(sdp, DO);
    if (error)
        goto fail_per_node;

    if (!(sb->s_flags & MS_RDONLY)) {
        error = gfs2_make_fs_rw(sdp);
        if (error) {
            fs_err(sdp, "can't make FS RW: %d\n", error);
            goto fail_threads;
        }
    }

    gfs2_glock_dq_uninit(&mount_gh);
    gfs2_online_uevent(sdp);
    return 0;

fail_threads:
    init_threads(sdp, UNDO);
fail_per_node:
    init_per_node(sdp, UNDO);
fail_inodes:
    init_inodes(sdp, UNDO);
fail_sb:
    if (sdp->sd_root_dir)
        dput(sdp->sd_root_dir);
    if (sdp->sd_master_dir)
        dput(sdp->sd_master_dir);
    if (sb->s_root)
        dput(sb->s_root);
    sb->s_root = NULL;
fail_locking:
    init_locking(sdp, &mount_gh, UNDO);
fail_lm:
    gfs2_gl_hash_clear(sdp);
    gfs2_lm_unmount(sdp);
fail_debug:
    gfs2_delete_debugfs_file(sdp);
    free_percpu(sdp->sd_lkstats);
    /* gfs2_sys_fs_del must be the last thing we do, since it causes
     * sysfs to call function gfs2_sbd_release, which frees sdp. */
    gfs2_sys_fs_del(sdp);
    sb->s_fs_info = NULL;
    return error;
}

static int set_gfs2_super(struct super_block *s, void *data)
{
    s->s_bdev = data;
    s->s_dev = s->s_bdev->bd_dev;

    /*
     * We set the bdi here to the queue backing, file systems can
     * overwrite this in ->fill_super()
     */
    s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
    return 0;
}

static int test_gfs2_super(struct super_block *s, void *ptr)
{
    struct block_device *bdev = ptr;
    return (bdev == s->s_bdev);
}

static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
               const char *dev_name, void *data)
{
    struct block_device *bdev;
    struct super_block *s;
    fmode_t mode = FMODE_READ | FMODE_EXCL;
    int error;
    struct gfs2_args args;
    struct gfs2_sbd *sdp;

    if (!(flags & MS_RDONLY))
        mode |= FMODE_WRITE;

    bdev = blkdev_get_by_path(dev_name, mode, fs_type);
    if (IS_ERR(bdev))
        return ERR_CAST(bdev);

    /*
     * once the super is inserted into the list by sget, s_umount
     * will protect the lockfs code from trying to start a snapshot
     * while we are mounting
     */
    mutex_lock(&bdev->bd_fsfreeze_mutex);
    if (bdev->bd_fsfreeze_count > 0) {
        mutex_unlock(&bdev->bd_fsfreeze_mutex);
        error = -EBUSY;
        goto error_bdev;
    }
    s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
    mutex_unlock(&bdev->bd_fsfreeze_mutex);
    error = PTR_ERR(s);
    if (IS_ERR(s))
        goto error_bdev;

    if (s->s_root)
        blkdev_put(bdev, mode);

    memset(&args, 0, sizeof(args));
    args.ar_quota = GFS2_QUOTA_DEFAULT;
    args.ar_data = GFS2_DATA_DEFAULT;
    args.ar_commit = 30;
    args.ar_statfs_quantum = 30;
    args.ar_quota_quantum = 60;
    args.ar_errors = GFS2_ERRORS_DEFAULT;

    error = gfs2_mount_args(&args, data);
    if (error) {
        printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
        goto error_super;
    }

    if (s->s_root) {
        error = -EBUSY;
        if ((flags ^ s->s_flags) & MS_RDONLY)
            goto error_super;
    } else {
        char b[BDEVNAME_SIZE];

        s->s_mode = mode;
        strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
        sb_set_blocksize(s, block_size(bdev));
        error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
        if (error)
            goto error_super;
        s->s_flags |= MS_ACTIVE;
        bdev->bd_super = s;
    }

    sdp = s->s_fs_info;
    if (args.ar_meta)
        return dget(sdp->sd_master_dir);
    else
        return dget(sdp->sd_root_dir);

error_super:
    deactivate_locked_super(s);
    return ERR_PTR(error);
error_bdev:
    blkdev_put(bdev, mode);
    return ERR_PTR(error);
}

static int set_meta_super(struct super_block *s, void *ptr)
{
    return -EINVAL;
}

static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
            int flags, const char *dev_name, void *data)
{
    struct super_block *s;
    struct gfs2_sbd *sdp;
    struct path path;
    int error;

    error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
    if (error) {
        printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
               dev_name, error);
        return ERR_PTR(error);
    }
    s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
         path.dentry->d_inode->i_sb->s_bdev);
    path_put(&path);
    if (IS_ERR(s)) {
        printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
        return ERR_CAST(s);
    }
    if ((flags ^ s->s_flags) & MS_RDONLY) {
        deactivate_locked_super(s);
        return ERR_PTR(-EBUSY);
    }
    sdp = s->s_fs_info;
    return dget(sdp->sd_master_dir);
}

static void gfs2_kill_sb(struct super_block *sb)
{
    struct gfs2_sbd *sdp = sb->s_fs_info;

    if (sdp == NULL) {
        kill_block_super(sb);
        return;
    }

    gfs2_meta_syncfs(sdp);
    dput(sdp->sd_root_dir);
    dput(sdp->sd_master_dir);
    sdp->sd_root_dir = NULL;
    sdp->sd_master_dir = NULL;
    shrink_dcache_sb(sb);
    gfs2_delete_debugfs_file(sdp);
    free_percpu(sdp->sd_lkstats);
    kill_block_super(sb);
}

struct file_system_type gfs2_fs_type = {
    .name = "gfs2",
    .fs_flags = FS_REQUIRES_DEV,
    .mount = gfs2_mount,
    .kill_sb = gfs2_kill_sb,
    .owner = THIS_MODULE,
};

struct file_system_type gfs2meta_fs_type = {
    .name = "gfs2meta",
    .fs_flags = FS_REQUIRES_DEV,
    .mount = gfs2_mount_meta,
    .owner = THIS_MODULE,
};