const: constify remaining file_operations

[safe/jmp/linux-2.6] / fs / ocfs2 / super.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * super.c
 *
 * load/unload driver, mount/dismount volumes
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/statfs.h>
#include <linux/moduleparam.h>
#include <linux/blkdev.h>
#include <linux/socket.h>
#include <linux/inet.h>
#include <linux/parser.h>
#include <linux/crc32.h>
#include <linux/debugfs.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/quotaops.h>
#include <linux/smp_lock.h>

#define MLOG_MASK_PREFIX ML_SUPER
#include <cluster/masklog.h>

#include "ocfs2.h"

/* this should be the only file to include a version 1 header */
#include "ocfs1_fs_compat.h"

#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "export.h"
#include "extent_map.h"
#include "heartbeat.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "namei.h"
#include "slot_map.h"
#include "super.h"
#include "sysfile.h"
#include "uptodate.h"
#include "ver.h"
#include "xattr.h"
#include "quota.h"
#include "refcounttree.h"

#include "buffer_head_io.h"

static struct kmem_cache *ocfs2_inode_cachep = NULL;
struct kmem_cache *ocfs2_dquot_cachep;
struct kmem_cache *ocfs2_qf_chunk_cachep;

/* OCFS2 needs to schedule several differnt types of work which
 * require cluster locking, disk I/O, recovery waits, etc. Since these
 * types of work tend to be heavy we avoid using the kernel events
 * workqueue and schedule on our own. */
struct workqueue_struct *ocfs2_wq = NULL;

static struct dentry *ocfs2_debugfs_root = NULL;

MODULE_AUTHOR("Oracle");
MODULE_LICENSE("GPL");

struct mount_options
{
        unsigned long   commit_interval;
        unsigned long   mount_opt;
        unsigned int    atime_quantum;
        signed short    slot;
        unsigned int    localalloc_opt;
        char            cluster_stack[OCFS2_STACK_LABEL_LEN + 1];
};

static int ocfs2_parse_options(struct super_block *sb, char *options,
                               struct mount_options *mopt,
                               int is_remount);
static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt);
static void ocfs2_put_super(struct super_block *sb);
static int ocfs2_mount_volume(struct super_block *sb);
static int ocfs2_remount(struct super_block *sb, int *flags, char *data);
static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err);
static int ocfs2_initialize_mem_caches(void);
static void ocfs2_free_mem_caches(void);
static void ocfs2_delete_osb(struct ocfs2_super *osb);

static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf);

static int ocfs2_sync_fs(struct super_block *sb, int wait);

static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb);
static int ocfs2_init_local_system_inodes(struct ocfs2_super *osb);
static void ocfs2_release_system_inodes(struct ocfs2_super *osb);
static int ocfs2_check_volume(struct ocfs2_super *osb);
static int ocfs2_verify_volume(struct ocfs2_dinode *di,
                               struct buffer_head *bh,
                               u32 sectsize,
                               struct ocfs2_blockcheck_stats *stats);
static int ocfs2_initialize_super(struct super_block *sb,
                                  struct buffer_head *bh,
                                  int sector_size,
                                  struct ocfs2_blockcheck_stats *stats);
static int ocfs2_get_sector(struct super_block *sb,
                            struct buffer_head **bh,
                            int block,
                            int sect_size);
static struct inode *ocfs2_alloc_inode(struct super_block *sb);
static void ocfs2_destroy_inode(struct inode *inode);
static int ocfs2_susp_quotas(struct ocfs2_super *osb, int unsuspend);
static int ocfs2_enable_quotas(struct ocfs2_super *osb);
static void ocfs2_disable_quotas(struct ocfs2_super *osb);

static const struct super_operations ocfs2_sops = {
        .statfs         = ocfs2_statfs,
        .alloc_inode    = ocfs2_alloc_inode,
        .destroy_inode  = ocfs2_destroy_inode,
        .drop_inode     = ocfs2_drop_inode,
        .clear_inode    = ocfs2_clear_inode,
        .delete_inode   = ocfs2_delete_inode,
        .sync_fs        = ocfs2_sync_fs,
        .put_super      = ocfs2_put_super,
        .remount_fs     = ocfs2_remount,
        .show_options   = ocfs2_show_options,
        .quota_read     = ocfs2_quota_read,
        .quota_write    = ocfs2_quota_write,
};

enum {
        Opt_barrier,
        Opt_err_panic,
        Opt_err_ro,
        Opt_intr,
        Opt_nointr,
        Opt_hb_none,
        Opt_hb_local,
        Opt_data_ordered,
        Opt_data_writeback,
        Opt_atime_quantum,
        Opt_slot,
        Opt_commit,
        Opt_localalloc,
        Opt_localflocks,
        Opt_stack,
        Opt_user_xattr,
        Opt_nouser_xattr,
        Opt_inode64,
        Opt_acl,
        Opt_noacl,
        Opt_usrquota,
        Opt_grpquota,
        Opt_err,
};

static const match_table_t tokens = {
        {Opt_barrier, "barrier=%u"},
        {Opt_err_panic, "errors=panic"},
        {Opt_err_ro, "errors=remount-ro"},
        {Opt_intr, "intr"},
        {Opt_nointr, "nointr"},
        {Opt_hb_none, OCFS2_HB_NONE},
        {Opt_hb_local, OCFS2_HB_LOCAL},
        {Opt_data_ordered, "data=ordered"},
        {Opt_data_writeback, "data=writeback"},
        {Opt_atime_quantum, "atime_quantum=%u"},
        {Opt_slot, "preferred_slot=%u"},
        {Opt_commit, "commit=%u"},
        {Opt_localalloc, "localalloc=%d"},
        {Opt_localflocks, "localflocks"},
        {Opt_stack, "cluster_stack=%s"},
        {Opt_user_xattr, "user_xattr"},
        {Opt_nouser_xattr, "nouser_xattr"},
        {Opt_inode64, "inode64"},
        {Opt_acl, "acl"},
        {Opt_noacl, "noacl"},
        {Opt_usrquota, "usrquota"},
        {Opt_grpquota, "grpquota"},
        {Opt_err, NULL}
};

#ifdef CONFIG_DEBUG_FS
static int ocfs2_osb_dump(struct ocfs2_super *osb, char *buf, int len)
{
        struct ocfs2_cluster_connection *cconn = osb->cconn;
        struct ocfs2_recovery_map *rm = osb->recovery_map;
        struct ocfs2_orphan_scan *os = &osb->osb_orphan_scan;
        int i, out = 0;

        out += snprintf(buf + out, len - out,
                        "%10s => Id: %-s  Uuid: %-s  Gen: 0x%X  Label: %-s\n",
                        "Device", osb->dev_str, osb->uuid_str,
                        osb->fs_generation, osb->vol_label);

        out += snprintf(buf + out, len - out,
                        "%10s => State: %d  Flags: 0x%lX\n", "Volume",
                        atomic_read(&osb->vol_state), osb->osb_flags);

        out += snprintf(buf + out, len - out,
                        "%10s => Block: %lu  Cluster: %d\n", "Sizes",
                        osb->sb->s_blocksize, osb->s_clustersize);

        out += snprintf(buf + out, len - out,
                        "%10s => Compat: 0x%X  Incompat: 0x%X  "
                        "ROcompat: 0x%X\n",
                        "Features", osb->s_feature_compat,
                        osb->s_feature_incompat, osb->s_feature_ro_compat);

        out += snprintf(buf + out, len - out,
                        "%10s => Opts: 0x%lX  AtimeQuanta: %u\n", "Mount",
                        osb->s_mount_opt, osb->s_atime_quantum);

        if (cconn) {
                out += snprintf(buf + out, len - out,
                                "%10s => Stack: %s  Name: %*s  "
                                "Version: %d.%d\n", "Cluster",
                                (*osb->osb_cluster_stack == '\0' ?
                                 "o2cb" : osb->osb_cluster_stack),
                                cconn->cc_namelen, cconn->cc_name,
                                cconn->cc_version.pv_major,
                                cconn->cc_version.pv_minor);
        }

        spin_lock(&osb->dc_task_lock);
        out += snprintf(buf + out, len - out,
                        "%10s => Pid: %d  Count: %lu  WakeSeq: %lu  "
                        "WorkSeq: %lu\n", "DownCnvt",
                        (osb->dc_task ?  task_pid_nr(osb->dc_task) : -1),
                        osb->blocked_lock_count, osb->dc_wake_sequence,
                        osb->dc_work_sequence);
        spin_unlock(&osb->dc_task_lock);

        spin_lock(&osb->osb_lock);
        out += snprintf(buf + out, len - out, "%10s => Pid: %d  Nodes:",
                        "Recovery",
                        (osb->recovery_thread_task ?
                         task_pid_nr(osb->recovery_thread_task) : -1));
        if (rm->rm_used == 0)
                out += snprintf(buf + out, len - out, " None\n");
        else {
                for (i = 0; i < rm->rm_used; i++)
                        out += snprintf(buf + out, len - out, " %d",
                                        rm->rm_entries[i]);
                out += snprintf(buf + out, len - out, "\n");
        }
        spin_unlock(&osb->osb_lock);

        out += snprintf(buf + out, len - out,
                        "%10s => Pid: %d  Interval: %lu  Needs: %d\n", "Commit",
                        (osb->commit_task ? task_pid_nr(osb->commit_task) : -1),
                        osb->osb_commit_interval,
                        atomic_read(&osb->needs_checkpoint));

        out += snprintf(buf + out, len - out,
                        "%10s => State: %d  TxnId: %lu  NumTxns: %d\n",
                        "Journal", osb->journal->j_state,
                        osb->journal->j_trans_id,
                        atomic_read(&osb->journal->j_num_trans));

        out += snprintf(buf + out, len - out,
                        "%10s => GlobalAllocs: %d  LocalAllocs: %d  "
                        "SubAllocs: %d  LAWinMoves: %d  SAExtends: %d\n",
                        "Stats",
                        atomic_read(&osb->alloc_stats.bitmap_data),
                        atomic_read(&osb->alloc_stats.local_data),
                        atomic_read(&osb->alloc_stats.bg_allocs),
                        atomic_read(&osb->alloc_stats.moves),
                        atomic_read(&osb->alloc_stats.bg_extends));

        out += snprintf(buf + out, len - out,
                        "%10s => State: %u  Descriptor: %llu  Size: %u bits  "
                        "Default: %u bits\n",
                        "LocalAlloc", osb->local_alloc_state,
                        (unsigned long long)osb->la_last_gd,
                        osb->local_alloc_bits, osb->local_alloc_default_bits);

        spin_lock(&osb->osb_lock);
        out += snprintf(buf + out, len - out,
                        "%10s => Slot: %d  NumStolen: %d\n", "Steal",
                        osb->s_inode_steal_slot,
                        atomic_read(&osb->s_num_inodes_stolen));
        spin_unlock(&osb->osb_lock);

        out += snprintf(buf + out, len - out, "OrphanScan => ");
        out += snprintf(buf + out, len - out, "Local: %u  Global: %u ",
                        os->os_count, os->os_seqno);
        out += snprintf(buf + out, len - out, " Last Scan: ");
        if (atomic_read(&os->os_state) == ORPHAN_SCAN_INACTIVE)
                out += snprintf(buf + out, len - out, "Disabled\n");
        else
                out += snprintf(buf + out, len - out, "%lu seconds ago\n",
                                (get_seconds() - os->os_scantime.tv_sec));

        out += snprintf(buf + out, len - out, "%10s => %3s  %10s\n",
                        "Slots", "Num", "RecoGen");
        for (i = 0; i < osb->max_slots; ++i) {
                out += snprintf(buf + out, len - out,
                                "%10s  %c %3d  %10d\n",
                                " ",
                                (i == osb->slot_num ? '*' : ' '),
                                i, osb->slot_recovery_generations[i]);
        }

        return out;
}

static int ocfs2_osb_debug_open(struct inode *inode, struct file *file)
{
        struct ocfs2_super *osb = inode->i_private;
        char *buf = NULL;

        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!buf)
                goto bail;

        i_size_write(inode, ocfs2_osb_dump(osb, buf, PAGE_SIZE));

        file->private_data = buf;

        return 0;
bail:
        return -ENOMEM;
}

static int ocfs2_debug_release(struct inode *inode, struct file *file)
{
        kfree(file->private_data);
        return 0;
}

static ssize_t ocfs2_debug_read(struct file *file, char __user *buf,
                                size_t nbytes, loff_t *ppos)
{
        return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
                                       i_size_read(file->f_mapping->host));
}
#else
static int ocfs2_osb_debug_open(struct inode *inode, struct file *file)
{
        return 0;
}
static int ocfs2_debug_release(struct inode *inode, struct file *file)
{
        return 0;
}
static ssize_t ocfs2_debug_read(struct file *file, char __user *buf,
                                size_t nbytes, loff_t *ppos)
{
        return 0;
}
#endif  /* CONFIG_DEBUG_FS */

static const struct file_operations ocfs2_osb_debug_fops = {
        .open =         ocfs2_osb_debug_open,
        .release =      ocfs2_debug_release,
        .read =         ocfs2_debug_read,
        .llseek =       generic_file_llseek,
};

static int ocfs2_sync_fs(struct super_block *sb, int wait)
{
        int status;
        tid_t target;
        struct ocfs2_super *osb = OCFS2_SB(sb);

        if (ocfs2_is_hard_readonly(osb))
                return -EROFS;

        if (wait) {
                status = ocfs2_flush_truncate_log(osb);
                if (status < 0)
                        mlog_errno(status);
        } else {
                ocfs2_schedule_truncate_log_flush(osb, 0);
        }

        if (jbd2_journal_start_commit(OCFS2_SB(sb)->journal->j_journal,
                                      &target)) {
                if (wait)
                        jbd2_log_wait_commit(OCFS2_SB(sb)->journal->j_journal,
                                             target);
        }
        return 0;
}

static int ocfs2_need_system_inode(struct ocfs2_super *osb, int ino)
{
        if (!OCFS2_HAS_RO_COMPAT_FEATURE(osb->sb, OCFS2_FEATURE_RO_COMPAT_USRQUOTA)
            && (ino == USER_QUOTA_SYSTEM_INODE
                || ino == LOCAL_USER_QUOTA_SYSTEM_INODE))
                return 0;
        if (!OCFS2_HAS_RO_COMPAT_FEATURE(osb->sb, OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)
            && (ino == GROUP_QUOTA_SYSTEM_INODE
                || ino == LOCAL_GROUP_QUOTA_SYSTEM_INODE))
                return 0;
        return 1;
}

static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb)
{
        struct inode *new = NULL;
        int status = 0;
        int i;

        mlog_entry_void();

        new = ocfs2_iget(osb, osb->root_blkno, OCFS2_FI_FLAG_SYSFILE, 0);
        if (IS_ERR(new)) {
                status = PTR_ERR(new);
                mlog_errno(status);
                goto bail;
        }
        osb->root_inode = new;

        new = ocfs2_iget(osb, osb->system_dir_blkno, OCFS2_FI_FLAG_SYSFILE, 0);
        if (IS_ERR(new)) {
                status = PTR_ERR(new);
                mlog_errno(status);
                goto bail;
        }
        osb->sys_root_inode = new;

        for (i = OCFS2_FIRST_ONLINE_SYSTEM_INODE;
             i <= OCFS2_LAST_GLOBAL_SYSTEM_INODE; i++) {
                if (!ocfs2_need_system_inode(osb, i))
                        continue;
                new = ocfs2_get_system_file_inode(osb, i, osb->slot_num);
                if (!new) {
                        ocfs2_release_system_inodes(osb);
                        status = -EINVAL;
                        mlog_errno(status);
                        /* FIXME: Should ERROR_RO_FS */
                        mlog(ML_ERROR, "Unable to load system inode %d, "
                             "possibly corrupt fs?", i);
                        goto bail;
                }
                // the array now has one ref, so drop this one
                iput(new);
        }

bail:
        mlog_exit(status);
        return status;
}

static int ocfs2_init_local_system_inodes(struct ocfs2_super *osb)
{
        struct inode *new = NULL;
        int status = 0;
        int i;

        mlog_entry_void();

        for (i = OCFS2_LAST_GLOBAL_SYSTEM_INODE + 1;
             i < NUM_SYSTEM_INODES;
             i++) {
                if (!ocfs2_need_system_inode(osb, i))
                        continue;
                new = ocfs2_get_system_file_inode(osb, i, osb->slot_num);
                if (!new) {
                        ocfs2_release_system_inodes(osb);
                        status = -EINVAL;
                        mlog(ML_ERROR, "status=%d, sysfile=%d, slot=%d\n",
                             status, i, osb->slot_num);
                        goto bail;
                }
                /* the array now has one ref, so drop this one */
                iput(new);
        }

bail:
        mlog_exit(status);
        return status;
}

static void ocfs2_release_system_inodes(struct ocfs2_super *osb)
{
        int i;
        struct inode *inode;

        mlog_entry_void();

        for (i = 0; i < NUM_SYSTEM_INODES; i++) {
                inode = osb->system_inodes[i];
                if (inode) {
                        iput(inode);
                        osb->system_inodes[i] = NULL;
                }
        }

        inode = osb->sys_root_inode;
        if (inode) {
                iput(inode);
                osb->sys_root_inode = NULL;
        }

        inode = osb->root_inode;
        if (inode) {
                iput(inode);
                osb->root_inode = NULL;
        }

        mlog_exit(0);
}

/* We're allocating fs objects, use GFP_NOFS */
static struct inode *ocfs2_alloc_inode(struct super_block *sb)
{
        struct ocfs2_inode_info *oi;

        oi = kmem_cache_alloc(ocfs2_inode_cachep, GFP_NOFS);
        if (!oi)
                return NULL;

        jbd2_journal_init_jbd_inode(&oi->ip_jinode, &oi->vfs_inode);
        return &oi->vfs_inode;
}

static void ocfs2_destroy_inode(struct inode *inode)
{
        kmem_cache_free(ocfs2_inode_cachep, OCFS2_I(inode));
}

static unsigned long long ocfs2_max_file_offset(unsigned int bbits,
                                                unsigned int cbits)
{
        unsigned int bytes = 1 << cbits;
        unsigned int trim = bytes;
        unsigned int bitshift = 32;

        /*
         * i_size and all block offsets in ocfs2 are always 64 bits
         * wide. i_clusters is 32 bits, in cluster-sized units. So on
         * 64 bit platforms, cluster size will be the limiting factor.
         */

#if BITS_PER_LONG == 32
# if defined(CONFIG_LBDAF)
        BUILD_BUG_ON(sizeof(sector_t) != 8);
        /*
         * We might be limited by page cache size.
         */
        if (bytes > PAGE_CACHE_SIZE) {
                bytes = PAGE_CACHE_SIZE;
                trim = 1;
                /*
                 * Shift by 31 here so that we don't get larger than
                 * MAX_LFS_FILESIZE
                 */
                bitshift = 31;
        }
# else
        /*
         * We are limited by the size of sector_t. Use block size, as
         * that's what we expose to the VFS.
         */
        bytes = 1 << bbits;
        trim = 1;
        bitshift = 31;
# endif
#endif

        /*
         * Trim by a whole cluster when we can actually approach the
         * on-disk limits. Otherwise we can overflow i_clusters when
         * an extent start is at the max offset.
         */
        return (((unsigned long long)bytes) << bitshift) - trim;
}

static int ocfs2_remount(struct super_block *sb, int *flags, char *data)
{
        int incompat_features;
        int ret = 0;
        struct mount_options parsed_options;
        struct ocfs2_super *osb = OCFS2_SB(sb);

        lock_kernel();

        if (!ocfs2_parse_options(sb, data, &parsed_options, 1)) {
                ret = -EINVAL;
                goto out;
        }

        if ((osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL) !=
            (parsed_options.mount_opt & OCFS2_MOUNT_HB_LOCAL)) {
                ret = -EINVAL;
                mlog(ML_ERROR, "Cannot change heartbeat mode on remount\n");
                goto out;
        }

        if ((osb->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK) !=
            (parsed_options.mount_opt & OCFS2_MOUNT_DATA_WRITEBACK)) {
                ret = -EINVAL;
                mlog(ML_ERROR, "Cannot change data mode on remount\n");
                goto out;
        }

        /* Probably don't want this on remount; it might
         * mess with other nodes */
        if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64) &&
            (parsed_options.mount_opt & OCFS2_MOUNT_INODE64)) {
                ret = -EINVAL;
                mlog(ML_ERROR, "Cannot enable inode64 on remount\n");
                goto out;
        }

        /* We're going to/from readonly mode. */
        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
                /* Disable quota accounting before remounting RO */
                if (*flags & MS_RDONLY) {
                        ret = ocfs2_susp_quotas(osb, 0);
                        if (ret < 0)
                                goto out;
                }
                /* Lock here so the check of HARD_RO and the potential
                 * setting of SOFT_RO is atomic. */
                spin_lock(&osb->osb_lock);
                if (osb->osb_flags & OCFS2_OSB_HARD_RO) {
                        mlog(ML_ERROR, "Remount on readonly device is forbidden.\n");
                        ret = -EROFS;
                        goto unlock_osb;
                }

                if (*flags & MS_RDONLY) {
                        mlog(0, "Going to ro mode.\n");
                        sb->s_flags |= MS_RDONLY;
                        osb->osb_flags |= OCFS2_OSB_SOFT_RO;
                } else {
                        mlog(0, "Making ro filesystem writeable.\n");

                        if (osb->osb_flags & OCFS2_OSB_ERROR_FS) {
                                mlog(ML_ERROR, "Cannot remount RDWR "
                                     "filesystem due to previous errors.\n");
                                ret = -EROFS;
                                goto unlock_osb;
                        }
                        incompat_features = OCFS2_HAS_RO_COMPAT_FEATURE(sb, ~OCFS2_FEATURE_RO_COMPAT_SUPP);
                        if (incompat_features) {
                                mlog(ML_ERROR, "Cannot remount RDWR because "
                                     "of unsupported optional features "
                                     "(%x).\n", incompat_features);
                                ret = -EINVAL;
                                goto unlock_osb;
                        }
                        sb->s_flags &= ~MS_RDONLY;
                        osb->osb_flags &= ~OCFS2_OSB_SOFT_RO;
                }
unlock_osb:
                spin_unlock(&osb->osb_lock);
                /* Enable quota accounting after remounting RW */
                if (!ret && !(*flags & MS_RDONLY)) {
                        if (sb_any_quota_suspended(sb))
                                ret = ocfs2_susp_quotas(osb, 1);
                        else
                                ret = ocfs2_enable_quotas(osb);
                        if (ret < 0) {
                                /* Return back changes... */
                                spin_lock(&osb->osb_lock);
                                sb->s_flags |= MS_RDONLY;
                                osb->osb_flags |= OCFS2_OSB_SOFT_RO;
                                spin_unlock(&osb->osb_lock);
                                goto out;
                        }
                }
        }

        if (!ret) {
                /* Only save off the new mount options in case of a successful
                 * remount. */
                if (!(osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_XATTR))
                        parsed_options.mount_opt &= ~OCFS2_MOUNT_POSIX_ACL;
                osb->s_mount_opt = parsed_options.mount_opt;
                osb->s_atime_quantum = parsed_options.atime_quantum;
                osb->preferred_slot = parsed_options.slot;
                if (parsed_options.commit_interval)
                        osb->osb_commit_interval = parsed_options.commit_interval;

                if (!ocfs2_is_hard_readonly(osb))
                        ocfs2_set_journal_params(osb);
        }
out:
        unlock_kernel();
        return ret;
}

static int ocfs2_sb_probe(struct super_block *sb,
                          struct buffer_head **bh,
                          int *sector_size,
                          struct ocfs2_blockcheck_stats *stats)
{
        int status, tmpstat;
        struct ocfs1_vol_disk_hdr *hdr;
        struct ocfs2_dinode *di;
        int blksize;

        *bh = NULL;

        /* may be > 512 */
        *sector_size = bdev_logical_block_size(sb->s_bdev);
        if (*sector_size > OCFS2_MAX_BLOCKSIZE) {
                mlog(ML_ERROR, "Hardware sector size too large: %d (max=%d)\n",
                     *sector_size, OCFS2_MAX_BLOCKSIZE);
                status = -EINVAL;
                goto bail;
        }

        /* Can this really happen? */
        if (*sector_size < OCFS2_MIN_BLOCKSIZE)
                *sector_size = OCFS2_MIN_BLOCKSIZE;

        /* check block zero for old format */
        status = ocfs2_get_sector(sb, bh, 0, *sector_size);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
        hdr = (struct ocfs1_vol_disk_hdr *) (*bh)->b_data;
        if (hdr->major_version == OCFS1_MAJOR_VERSION) {
                mlog(ML_ERROR, "incompatible version: %u.%u\n",
                     hdr->major_version, hdr->minor_version);
                status = -EINVAL;
        }
        if (memcmp(hdr->signature, OCFS1_VOLUME_SIGNATURE,
                   strlen(OCFS1_VOLUME_SIGNATURE)) == 0) {
                mlog(ML_ERROR, "incompatible volume signature: %8s\n",
                     hdr->signature);
                status = -EINVAL;
        }
        brelse(*bh);
        *bh = NULL;
        if (status < 0) {
                mlog(ML_ERROR, "This is an ocfs v1 filesystem which must be "
                     "upgraded before mounting with ocfs v2\n");
                goto bail;
        }

        /*
         * Now check at magic offset for 512, 1024, 2048, 4096
         * blocksizes.  4096 is the maximum blocksize because it is
         * the minimum clustersize.
         */
        status = -EINVAL;
        for (blksize = *sector_size;
             blksize <= OCFS2_MAX_BLOCKSIZE;
             blksize <<= 1) {
                tmpstat = ocfs2_get_sector(sb, bh,
                                           OCFS2_SUPER_BLOCK_BLKNO,
                                           blksize);
                if (tmpstat < 0) {
                        status = tmpstat;
                        mlog_errno(status);
                        goto bail;
                }
                di = (struct ocfs2_dinode *) (*bh)->b_data;
                memset(stats, 0, sizeof(struct ocfs2_blockcheck_stats));
                spin_lock_init(&stats->b_lock);
                status = ocfs2_verify_volume(di, *bh, blksize, stats);
                if (status >= 0)
                        goto bail;
                brelse(*bh);
                *bh = NULL;
                if (status != -EAGAIN)
                        break;
        }

bail:
        return status;
}

static int ocfs2_verify_heartbeat(struct ocfs2_super *osb)
{
        if (ocfs2_mount_local(osb)) {
                if (osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL) {
                        mlog(ML_ERROR, "Cannot heartbeat on a locally "
                             "mounted device.\n");
                        return -EINVAL;
                }
        }

        if (ocfs2_userspace_stack(osb)) {
                if (osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL) {
                        mlog(ML_ERROR, "Userspace stack expected, but "
                             "o2cb heartbeat arguments passed to mount\n");
                        return -EINVAL;
                }
        }

        if (!(osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL)) {
                if (!ocfs2_mount_local(osb) && !ocfs2_is_hard_readonly(osb) &&
                    !ocfs2_userspace_stack(osb)) {
                        mlog(ML_ERROR, "Heartbeat has to be started to mount "
                             "a read-write clustered device.\n");
                        return -EINVAL;
                }
        }

        return 0;
}

/*
 * If we're using a userspace stack, mount should have passed
 * a name that matches the disk.  If not, mount should not
 * have passed a stack.
 */
static int ocfs2_verify_userspace_stack(struct ocfs2_super *osb,
                                        struct mount_options *mopt)
{
        if (!ocfs2_userspace_stack(osb) && mopt->cluster_stack[0]) {
                mlog(ML_ERROR,
                     "cluster stack passed to mount, but this filesystem "
                     "does not support it\n");
                return -EINVAL;
        }

        if (ocfs2_userspace_stack(osb) &&
            strncmp(osb->osb_cluster_stack, mopt->cluster_stack,
                    OCFS2_STACK_LABEL_LEN)) {
                mlog(ML_ERROR,
                     "cluster stack passed to mount (\"%s\") does not "
                     "match the filesystem (\"%s\")\n",
                     mopt->cluster_stack,
                     osb->osb_cluster_stack);
                return -EINVAL;
        }

        return 0;
}

static int ocfs2_susp_quotas(struct ocfs2_super *osb, int unsuspend)
{
        int type;
        struct super_block *sb = osb->sb;
        unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,
                                             OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};
        int status = 0;

        for (type = 0; type < MAXQUOTAS; type++) {
                if (!OCFS2_HAS_RO_COMPAT_FEATURE(sb, feature[type]))
                        continue;
                if (unsuspend)
                        status = vfs_quota_enable(
                                        sb_dqopt(sb)->files[type],
                                        type, QFMT_OCFS2,
                                        DQUOT_SUSPENDED);
                else
                        status = vfs_quota_disable(sb, type,
                                                   DQUOT_SUSPENDED);
                if (status < 0)
                        break;
        }
        if (status < 0)
                mlog(ML_ERROR, "Failed to suspend/unsuspend quotas on "
                     "remount (error = %d).\n", status);
        return status;
}

static int ocfs2_enable_quotas(struct ocfs2_super *osb)
{
        struct inode *inode[MAXQUOTAS] = { NULL, NULL };
        struct super_block *sb = osb->sb;
        unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,
                                             OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};
        unsigned int ino[MAXQUOTAS] = { LOCAL_USER_QUOTA_SYSTEM_INODE,
                                        LOCAL_GROUP_QUOTA_SYSTEM_INODE };
        int status;
        int type;

        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NEGATIVE_USAGE;
        for (type = 0; type < MAXQUOTAS; type++) {
                if (!OCFS2_HAS_RO_COMPAT_FEATURE(sb, feature[type]))
                        continue;
                inode[type] = ocfs2_get_system_file_inode(osb, ino[type],
                                                        osb->slot_num);
                if (!inode[type]) {
                        status = -ENOENT;
                        goto out_quota_off;
                }
                status = vfs_quota_enable(inode[type], type, QFMT_OCFS2,
                                                DQUOT_USAGE_ENABLED);
                if (status < 0)
                        goto out_quota_off;
        }

        for (type = 0; type < MAXQUOTAS; type++)
                iput(inode[type]);
        return 0;
out_quota_off:
        ocfs2_disable_quotas(osb);
        for (type = 0; type < MAXQUOTAS; type++)
                iput(inode[type]);
        mlog_errno(status);
        return status;
}

static void ocfs2_disable_quotas(struct ocfs2_super *osb)
{
        int type;
        struct inode *inode;
        struct super_block *sb = osb->sb;

        /* We mostly ignore errors in this function because there's not much
         * we can do when we see them */
        for (type = 0; type < MAXQUOTAS; type++) {
                if (!sb_has_quota_loaded(sb, type))
                        continue;
                inode = igrab(sb->s_dquot.files[type]);
                /* Turn off quotas. This will remove all dquot structures from
                 * memory and so they will be automatically synced to global
                 * quota files */
                vfs_quota_disable(sb, type, DQUOT_USAGE_ENABLED |
                                            DQUOT_LIMITS_ENABLED);
                if (!inode)
                        continue;
                iput(inode);
        }
}

/* Handle quota on quotactl */
static int ocfs2_quota_on(struct super_block *sb, int type, int format_id,
                          char *path, int remount)
{
        unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,
                                             OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};

        if (!OCFS2_HAS_RO_COMPAT_FEATURE(sb, feature[type]))
                return -EINVAL;

        if (remount)
                return 0;       /* Just ignore it has been handled in
                                 * ocfs2_remount() */
        return vfs_quota_enable(sb_dqopt(sb)->files[type], type,
                                    format_id, DQUOT_LIMITS_ENABLED);
}

/* Handle quota off quotactl */
static int ocfs2_quota_off(struct super_block *sb, int type, int remount)
{
        if (remount)
                return 0;       /* Ignore now and handle later in
                                 * ocfs2_remount() */
        return vfs_quota_disable(sb, type, DQUOT_LIMITS_ENABLED);
}

static const struct quotactl_ops ocfs2_quotactl_ops = {
        .quota_on       = ocfs2_quota_on,
        .quota_off      = ocfs2_quota_off,
        .quota_sync     = vfs_quota_sync,
        .get_info       = vfs_get_dqinfo,
        .set_info       = vfs_set_dqinfo,
        .get_dqblk      = vfs_get_dqblk,
        .set_dqblk      = vfs_set_dqblk,
};

static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
{
        struct dentry *root;
        int status, sector_size;
        struct mount_options parsed_options;
        struct inode *inode = NULL;
        struct ocfs2_super *osb = NULL;
        struct buffer_head *bh = NULL;
        char nodestr[8];
        struct ocfs2_blockcheck_stats stats;

        mlog_entry("%p, %p, %i", sb, data, silent);

        if (!ocfs2_parse_options(sb, data, &parsed_options, 0)) {
                status = -EINVAL;
                goto read_super_error;
        }

        /* probe for superblock */
        status = ocfs2_sb_probe(sb, &bh, &sector_size, &stats);
        if (status < 0) {
                mlog(ML_ERROR, "superblock probe failed!\n");
                goto read_super_error;
        }

        status = ocfs2_initialize_super(sb, bh, sector_size, &stats);
        osb = OCFS2_SB(sb);
        if (status < 0) {
                mlog_errno(status);
                goto read_super_error;
        }
        brelse(bh);
        bh = NULL;

        if (!(osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_XATTR))
                parsed_options.mount_opt &= ~OCFS2_MOUNT_POSIX_ACL;

        osb->s_mount_opt = parsed_options.mount_opt;
        osb->s_atime_quantum = parsed_options.atime_quantum;
        osb->preferred_slot = parsed_options.slot;
        osb->osb_commit_interval = parsed_options.commit_interval;
        osb->local_alloc_default_bits = ocfs2_megabytes_to_clusters(sb, parsed_options.localalloc_opt);
        osb->local_alloc_bits = osb->local_alloc_default_bits;
        if (osb->s_mount_opt & OCFS2_MOUNT_USRQUOTA &&
            !OCFS2_HAS_RO_COMPAT_FEATURE(sb,
                                         OCFS2_FEATURE_RO_COMPAT_USRQUOTA)) {
                status = -EINVAL;
                mlog(ML_ERROR, "User quotas were requested, but this "
                     "filesystem does not have the feature enabled.\n");
                goto read_super_error;
        }
        if (osb->s_mount_opt & OCFS2_MOUNT_GRPQUOTA &&
            !OCFS2_HAS_RO_COMPAT_FEATURE(sb,
                                         OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)) {
                status = -EINVAL;
                mlog(ML_ERROR, "Group quotas were requested, but this "
                     "filesystem does not have the feature enabled.\n");
                goto read_super_error;
        }

        status = ocfs2_verify_userspace_stack(osb, &parsed_options);
        if (status)
                goto read_super_error;

        sb->s_magic = OCFS2_SUPER_MAGIC;

        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
                ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);

        /* Hard readonly mode only if: bdev_read_only, MS_RDONLY,
         * heartbeat=none */
        if (bdev_read_only(sb->s_bdev)) {
                if (!(sb->s_flags & MS_RDONLY)) {
                        status = -EACCES;
                        mlog(ML_ERROR, "Readonly device detected but readonly "
                             "mount was not specified.\n");
                        goto read_super_error;
                }

                /* You should not be able to start a local heartbeat
                 * on a readonly device. */
                if (osb->s_mount_opt & OCFS2_MOUNT_HB_LOCAL) {
                        status = -EROFS;
                        mlog(ML_ERROR, "Local heartbeat specified on readonly "
                             "device.\n");
                        goto read_super_error;
                }

                status = ocfs2_check_journals_nolocks(osb);
                if (status < 0) {
                        if (status == -EROFS)
                                mlog(ML_ERROR, "Recovery required on readonly "
                                     "file system, but write access is "
                                     "unavailable.\n");
                        else
                                mlog_errno(status);                     
                        goto read_super_error;
                }

                ocfs2_set_ro_flag(osb, 1);

                printk(KERN_NOTICE "Readonly device detected. No cluster "
                       "services will be utilized for this mount. Recovery "
                       "will be skipped.\n");
        }

        if (!ocfs2_is_hard_readonly(osb)) {
                if (sb->s_flags & MS_RDONLY)
                        ocfs2_set_ro_flag(osb, 0);
        }

        status = ocfs2_verify_heartbeat(osb);
        if (status < 0) {
                mlog_errno(status);
                goto read_super_error;
        }

        osb->osb_debug_root = debugfs_create_dir(osb->uuid_str,
                                                 ocfs2_debugfs_root);
        if (!osb->osb_debug_root) {
                status = -EINVAL;
                mlog(ML_ERROR, "Unable to create per-mount debugfs root.\n");
                goto read_super_error;
        }

        osb->osb_ctxt = debugfs_create_file("fs_state", S_IFREG|S_IRUSR,
                                            osb->osb_debug_root,
                                            osb,
                                            &ocfs2_osb_debug_fops);
        if (!osb->osb_ctxt) {
                status = -EINVAL;
                mlog_errno(status);
                goto read_super_error;
        }

        if (ocfs2_meta_ecc(osb)) {
                status = ocfs2_blockcheck_stats_debugfs_install(
                                                &osb->osb_ecc_stats,
                                                osb->osb_debug_root);
                if (status) {
                        mlog(ML_ERROR,
                             "Unable to create blockcheck statistics "
                             "files\n");
                        goto read_super_error;
                }
        }

        status = ocfs2_mount_volume(sb);
        if (osb->root_inode)
                inode = igrab(osb->root_inode);

        if (status < 0)
                goto read_super_error;

        if (!inode) {
                status = -EIO;
                mlog_errno(status);
                goto read_super_error;
        }

        root = d_alloc_root(inode);
        if (!root) {
                status = -ENOMEM;
                mlog_errno(status);
                goto read_super_error;
        }

        sb->s_root = root;

        ocfs2_complete_mount_recovery(osb);

        if (ocfs2_mount_local(osb))
                snprintf(nodestr, sizeof(nodestr), "local");
        else
                snprintf(nodestr, sizeof(nodestr), "%u", osb->node_num);

        printk(KERN_INFO "ocfs2: Mounting device (%s) on (node %s, slot %d) "
               "with %s data mode.\n",
               osb->dev_str, nodestr, osb->slot_num,
               osb->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK ? "writeback" :
               "ordered");

        atomic_set(&osb->vol_state, VOLUME_MOUNTED);
        wake_up(&osb->osb_mount_event);

        /* Now we can initialize quotas because we can afford to wait
         * for cluster locks recovery now. That also means that truncation
         * log recovery can happen but that waits for proper quota setup */
        if (!(sb->s_flags & MS_RDONLY)) {
                status = ocfs2_enable_quotas(osb);
                if (status < 0) {
                        /* We have to err-out specially here because
                         * s_root is already set */
                        mlog_errno(status);
                        atomic_set(&osb->vol_state, VOLUME_DISABLED);
                        wake_up(&osb->osb_mount_event);
                        mlog_exit(status);
                        return status;
                }
        }

        ocfs2_complete_quota_recovery(osb);

        /* Now we wake up again for processes waiting for quotas */
        atomic_set(&osb->vol_state, VOLUME_MOUNTED_QUOTAS);
        wake_up(&osb->osb_mount_event);

        /* Start this when the mount is almost sure of being successful */
        ocfs2_orphan_scan_start(osb);

        mlog_exit(status);
        return status;

read_super_error:
        brelse(bh);

        if (inode)
                iput(inode);

        if (osb) {
                atomic_set(&osb->vol_state, VOLUME_DISABLED);
                wake_up(&osb->osb_mount_event);
                ocfs2_dismount_volume(sb, 1);
        }

        mlog_exit(status);
        return status;
}

static int ocfs2_get_sb(struct file_system_type *fs_type,
                        int flags,
                        const char *dev_name,
                        void *data,
                        struct vfsmount *mnt)
{
        return get_sb_bdev(fs_type, flags, dev_name, data, ocfs2_fill_super,
                           mnt);
}

static void ocfs2_kill_sb(struct super_block *sb)
{
        struct ocfs2_super *osb = OCFS2_SB(sb);

        /* Failed mount? */
        if (!osb || atomic_read(&osb->vol_state) == VOLUME_DISABLED)
                goto out;

        /* Prevent further queueing of inode drop events */
        spin_lock(&dentry_list_lock);
        ocfs2_set_osb_flag(osb, OCFS2_OSB_DROP_DENTRY_LOCK_IMMED);
        spin_unlock(&dentry_list_lock);
        /* Wait for work to finish and/or remove it */
        cancel_work_sync(&osb->dentry_lock_work);
out:
        kill_block_super(sb);
}

static struct file_system_type ocfs2_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "ocfs2",
        .get_sb         = ocfs2_get_sb, /* is this called when we mount
                                        * the fs? */
        .kill_sb        = ocfs2_kill_sb,

        .fs_flags       = FS_REQUIRES_DEV|FS_RENAME_DOES_D_MOVE,
        .next           = NULL
};

static int ocfs2_parse_options(struct super_block *sb,
                               char *options,
                               struct mount_options *mopt,
                               int is_remount)
{
        int status;
        char *p;

        mlog_entry("remount: %d, options: \"%s\"\n", is_remount,
                   options ? options : "(none)");

        mopt->commit_interval = 0;
        mopt->mount_opt = 0;
        mopt->atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
        mopt->slot = OCFS2_INVALID_SLOT;
        mopt->localalloc_opt = OCFS2_DEFAULT_LOCAL_ALLOC_SIZE;
        mopt->cluster_stack[0] = '\0';

        if (!options) {
                status = 1;
                goto bail;
        }

        while ((p = strsep(&options, ",")) != NULL) {
                int token, option;
                substring_t args[MAX_OPT_ARGS];

                if (!*p)
                        continue;

                token = match_token(p, tokens, args);
                switch (token) {
                case Opt_hb_local:
                        mopt->mount_opt |= OCFS2_MOUNT_HB_LOCAL;
                        break;
                case Opt_hb_none:
                        mopt->mount_opt &= ~OCFS2_MOUNT_HB_LOCAL;
                        break;
                case Opt_barrier:
                        if (match_int(&args[0], &option)) {
                                status = 0;
                                goto bail;
                        }
                        if (option)
                                mopt->mount_opt |= OCFS2_MOUNT_BARRIER;
                        else
                                mopt->mount_opt &= ~OCFS2_MOUNT_BARRIER;
                        break;
                case Opt_intr:
                        mopt->mount_opt &= ~OCFS2_MOUNT_NOINTR;
                        break;
                case Opt_nointr:
                        mopt->mount_opt |= OCFS2_MOUNT_NOINTR;
                        break;
                case Opt_err_panic:
                        mopt->mount_opt |= OCFS2_MOUNT_ERRORS_PANIC;
                        break;
                case Opt_err_ro:
                        mopt->mount_opt &= ~OCFS2_MOUNT_ERRORS_PANIC;
                        break;
                case Opt_data_ordered:
                        mopt->mount_opt &= ~OCFS2_MOUNT_DATA_WRITEBACK;
                        break;
                case Opt_data_writeback:
                        mopt->mount_opt |= OCFS2_MOUNT_DATA_WRITEBACK;
                        break;
                case Opt_user_xattr:
                        mopt->mount_opt &= ~OCFS2_MOUNT_NOUSERXATTR;
                        break;
                case Opt_nouser_xattr:
                        mopt->mount_opt |= OCFS2_MOUNT_NOUSERXATTR;
                        break;
                case Opt_atime_quantum:
                        if (match_int(&args[0], &option)) {
                                status = 0;
                                goto bail;
                        }
                        if (option >= 0)
                                mopt->atime_quantum = option;
                        break;
                case Opt_slot:
                        option = 0;
                        if (match_int(&args[0], &option)) {
                                status = 0;
                                goto bail;
                        }
                        if (option)
                                mopt->slot = (s16)option;
                        break;
                case Opt_commit:
                        option = 0;
                        if (match_int(&args[0], &option)) {
                                status = 0;
                                goto bail;
                        }
                        if (option < 0)
                                return 0;
                        if (option == 0)
                                option = JBD2_DEFAULT_MAX_COMMIT_AGE;
                        mopt->commit_interval = HZ * option;
                        break;
                case Opt_localalloc:
                        option = 0;
                        if (match_int(&args[0], &option)) {
                                status = 0;
                                goto bail;
                        }
                        if (option >= 0 && (option <= ocfs2_local_alloc_size(sb) * 8))
                                mopt->localalloc_opt = option;
                        break;
                case Opt_localflocks:
                        /*
                         * Changing this during remount could race
                         * flock() requests, or "unbalance" existing
                         * ones (e.g., a lock is taken in one mode but
                         * dropped in the other). If users care enough
                         * to flip locking modes during remount, we
                         * could add a "local" flag to individual
                         * flock structures for proper tracking of
                         * state.
                         */
                        if (!is_remount)
                                mopt->mount_opt |= OCFS2_MOUNT_LOCALFLOCKS;
                        break;
                case Opt_stack:
                        /* Check both that the option we were passed
                         * is of the right length and that it is a proper
                         * string of the right length.
                         */
                        if (((args[0].to - args[0].from) !=
                             OCFS2_STACK_LABEL_LEN) ||
                            (strnlen(args[0].from,
                                     OCFS2_STACK_LABEL_LEN) !=
                             OCFS2_STACK_LABEL_LEN)) {
                                mlog(ML_ERROR,
                                     "Invalid cluster_stack option\n");
                                status = 0;
                                goto bail;
                        }
                        memcpy(mopt->cluster_stack, args[0].from,
                               OCFS2_STACK_LABEL_LEN);
                        mopt->cluster_stack[OCFS2_STACK_LABEL_LEN] = '\0';
                        break;
                case Opt_inode64:
                        mopt->mount_opt |= OCFS2_MOUNT_INODE64;
                        break;
                case Opt_usrquota:
                        /* We check only on remount, otherwise features
                         * aren't yet initialized. */
                        if (is_remount && !OCFS2_HAS_RO_COMPAT_FEATURE(sb,
                            OCFS2_FEATURE_RO_COMPAT_USRQUOTA)) {
                                mlog(ML_ERROR, "User quota requested but "
                                     "filesystem feature is not set\n");
                                status = 0;
                                goto bail;
                        }
                        mopt->mount_opt |= OCFS2_MOUNT_USRQUOTA;
                        break;
                case Opt_grpquota:
                        if (is_remount && !OCFS2_HAS_RO_COMPAT_FEATURE(sb,
                            OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)) {
                                mlog(ML_ERROR, "Group quota requested but "
                                     "filesystem feature is not set\n");
                                status = 0;
                                goto bail;
                        }
                        mopt->mount_opt |= OCFS2_MOUNT_GRPQUOTA;
                        break;
#ifdef CONFIG_OCFS2_FS_POSIX_ACL
                case Opt_acl:
                        mopt->mount_opt |= OCFS2_MOUNT_POSIX_ACL;
                        break;
                case Opt_noacl:
                        mopt->mount_opt &= ~OCFS2_MOUNT_POSIX_ACL;
                        break;
#else
                case Opt_acl:
                case Opt_noacl:
                        printk(KERN_INFO "ocfs2 (no)acl options not supported\n");
                        break;
#endif
                default:
                        mlog(ML_ERROR,
                             "Unrecognized mount option \"%s\" "
                             "or missing value\n", p);
                        status = 0;
                        goto bail;
                }
        }

        status = 1;

bail:
        mlog_exit(status);
        return status;
}

static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
{
        struct ocfs2_super *osb = OCFS2_SB(mnt->mnt_sb);
        unsigned long opts = osb->s_mount_opt;
        unsigned int local_alloc_megs;

        if (opts & OCFS2_MOUNT_HB_LOCAL)
                seq_printf(s, ",_netdev,heartbeat=local");
        else
                seq_printf(s, ",heartbeat=none");

        if (opts & OCFS2_MOUNT_NOINTR)
                seq_printf(s, ",nointr");

        if (opts & OCFS2_MOUNT_DATA_WRITEBACK)
                seq_printf(s, ",data=writeback");
        else
                seq_printf(s, ",data=ordered");

        if (opts & OCFS2_MOUNT_BARRIER)
                seq_printf(s, ",barrier=1");

        if (opts & OCFS2_MOUNT_ERRORS_PANIC)
                seq_printf(s, ",errors=panic");
        else
                seq_printf(s, ",errors=remount-ro");

        if (osb->preferred_slot != OCFS2_INVALID_SLOT)
                seq_printf(s, ",preferred_slot=%d", osb->preferred_slot);

        if (osb->s_atime_quantum != OCFS2_DEFAULT_ATIME_QUANTUM)
                seq_printf(s, ",atime_quantum=%u", osb->s_atime_quantum);

        if (osb->osb_commit_interval)
                seq_printf(s, ",commit=%u",
                           (unsigned) (osb->osb_commit_interval / HZ));

        local_alloc_megs = osb->local_alloc_bits >> (20 - osb->s_clustersize_bits);
        if (local_alloc_megs != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
                seq_printf(s, ",localalloc=%d", local_alloc_megs);

        if (opts & OCFS2_MOUNT_LOCALFLOCKS)
                seq_printf(s, ",localflocks,");

        if (osb->osb_cluster_stack[0])
                seq_printf(s, ",cluster_stack=%.*s", OCFS2_STACK_LABEL_LEN,
                           osb->osb_cluster_stack);
        if (opts & OCFS2_MOUNT_USRQUOTA)
                seq_printf(s, ",usrquota");
        if (opts & OCFS2_MOUNT_GRPQUOTA)
                seq_printf(s, ",grpquota");

        if (opts & OCFS2_MOUNT_NOUSERXATTR)
                seq_printf(s, ",nouser_xattr");
        else
                seq_printf(s, ",user_xattr");

        if (opts & OCFS2_MOUNT_INODE64)
                seq_printf(s, ",inode64");

#ifdef CONFIG_OCFS2_FS_POSIX_ACL
        if (opts & OCFS2_MOUNT_POSIX_ACL)
                seq_printf(s, ",acl");
        else
                seq_printf(s, ",noacl");
#endif

        return 0;
}

static int __init ocfs2_init(void)
{
        int status;

        mlog_entry_void();

        ocfs2_print_version();

        status = init_ocfs2_uptodate_cache();
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        status = ocfs2_initialize_mem_caches();
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        ocfs2_wq = create_singlethread_workqueue("ocfs2_wq");
        if (!ocfs2_wq) {
                status = -ENOMEM;
                goto leave;
        }

        ocfs2_debugfs_root = debugfs_create_dir("ocfs2", NULL);
        if (!ocfs2_debugfs_root) {
                status = -EFAULT;
                mlog(ML_ERROR, "Unable to create ocfs2 debugfs root.\n");
        }

        status = ocfs2_quota_setup();
        if (status)
                goto leave;

        ocfs2_set_locking_protocol();

        status = register_quota_format(&ocfs2_quota_format);
leave:
        if (status < 0) {
                ocfs2_quota_shutdown();
                ocfs2_free_mem_caches();
                exit_ocfs2_uptodate_cache();
        }

        mlog_exit(status);

        if (status >= 0) {
                return register_filesystem(&ocfs2_fs_type);
        } else
                return -1;
}

static void __exit ocfs2_exit(void)
{
        mlog_entry_void();

        ocfs2_quota_shutdown();

        if (ocfs2_wq) {
                flush_workqueue(ocfs2_wq);
                destroy_workqueue(ocfs2_wq);
        }

        unregister_quota_format(&ocfs2_quota_format);

        debugfs_remove(ocfs2_debugfs_root);

        ocfs2_free_mem_caches();

        unregister_filesystem(&ocfs2_fs_type);

        exit_ocfs2_uptodate_cache();

        mlog_exit_void();
}

static void ocfs2_put_super(struct super_block *sb)
{
        mlog_entry("(0x%p)\n", sb);

        lock_kernel();

        ocfs2_sync_blockdev(sb);
        ocfs2_dismount_volume(sb, 0);

        unlock_kernel();

        mlog_exit_void();
}

static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
{
        struct ocfs2_super *osb;
        u32 numbits, freebits;
        int status;
        struct ocfs2_dinode *bm_lock;
        struct buffer_head *bh = NULL;
        struct inode *inode = NULL;

        mlog_entry("(%p, %p)\n", dentry->d_sb, buf);

        osb = OCFS2_SB(dentry->d_sb);

        inode = ocfs2_get_system_file_inode(osb,
                                            GLOBAL_BITMAP_SYSTEM_INODE,
                                            OCFS2_INVALID_SLOT);
        if (!inode) {
                mlog(ML_ERROR, "failed to get bitmap inode\n");
                status = -EIO;
                goto bail;
        }

        status = ocfs2_inode_lock(inode, &bh, 0);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }

        bm_lock = (struct ocfs2_dinode *) bh->b_data;

        numbits = le32_to_cpu(bm_lock->id1.bitmap1.i_total);
        freebits = numbits - le32_to_cpu(bm_lock->id1.bitmap1.i_used);

        buf->f_type = OCFS2_SUPER_MAGIC;
        buf->f_bsize = dentry->d_sb->s_blocksize;
        buf->f_namelen = OCFS2_MAX_FILENAME_LEN;
        buf->f_blocks = ((sector_t) numbits) *
                        (osb->s_clustersize >> osb->sb->s_blocksize_bits);
        buf->f_bfree = ((sector_t) freebits) *
                       (osb->s_clustersize >> osb->sb->s_blocksize_bits);
        buf->f_bavail = buf->f_bfree;
        buf->f_files = numbits;
        buf->f_ffree = freebits;

        brelse(bh);

        ocfs2_inode_unlock(inode, 0);
        status = 0;
bail:
        if (inode)
                iput(inode);

        mlog_exit(status);

        return status;
}

static void ocfs2_inode_init_once(void *data)
{
        struct ocfs2_inode_info *oi = data;

        oi->ip_flags = 0;
        oi->ip_open_count = 0;
        spin_lock_init(&oi->ip_lock);
        ocfs2_extent_map_init(&oi->vfs_inode);
        INIT_LIST_HEAD(&oi->ip_io_markers);
        oi->ip_dir_start_lookup = 0;

        init_rwsem(&oi->ip_alloc_sem);
        init_rwsem(&oi->ip_xattr_sem);
        mutex_init(&oi->ip_io_mutex);

        oi->ip_blkno = 0ULL;
        oi->ip_clusters = 0;

        ocfs2_lock_res_init_once(&oi->ip_rw_lockres);
        ocfs2_lock_res_init_once(&oi->ip_inode_lockres);
        ocfs2_lock_res_init_once(&oi->ip_open_lockres);

        ocfs2_metadata_cache_init(INODE_CACHE(&oi->vfs_inode),
                                  &ocfs2_inode_caching_ops);

        inode_init_once(&oi->vfs_inode);
}

static int ocfs2_initialize_mem_caches(void)
{
        ocfs2_inode_cachep = kmem_cache_create("ocfs2_inode_cache",
                                       sizeof(struct ocfs2_inode_info),
                                       0,
                                       (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
                                                SLAB_MEM_SPREAD),
                                       ocfs2_inode_init_once);
        ocfs2_dquot_cachep = kmem_cache_create("ocfs2_dquot_cache",
                                        sizeof(struct ocfs2_dquot),
                                        0,
                                        (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
                                                SLAB_MEM_SPREAD),
                                        NULL);
        ocfs2_qf_chunk_cachep = kmem_cache_create("ocfs2_qf_chunk_cache",
                                        sizeof(struct ocfs2_quota_chunk),
                                        0,
                                        (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
                                        NULL);
        if (!ocfs2_inode_cachep || !ocfs2_dquot_cachep ||
            !ocfs2_qf_chunk_cachep) {
                if (ocfs2_inode_cachep)
                        kmem_cache_destroy(ocfs2_inode_cachep);
                if (ocfs2_dquot_cachep)
                        kmem_cache_destroy(ocfs2_dquot_cachep);
                if (ocfs2_qf_chunk_cachep)
                        kmem_cache_destroy(ocfs2_qf_chunk_cachep);
                return -ENOMEM;
        }

        return 0;
}

static void ocfs2_free_mem_caches(void)
{
        if (ocfs2_inode_cachep)
                kmem_cache_destroy(ocfs2_inode_cachep);
        ocfs2_inode_cachep = NULL;

        if (ocfs2_dquot_cachep)
                kmem_cache_destroy(ocfs2_dquot_cachep);
        ocfs2_dquot_cachep = NULL;

        if (ocfs2_qf_chunk_cachep)
                kmem_cache_destroy(ocfs2_qf_chunk_cachep);
        ocfs2_qf_chunk_cachep = NULL;
}

static int ocfs2_get_sector(struct super_block *sb,
                            struct buffer_head **bh,
                            int block,
                            int sect_size)
{
        if (!sb_set_blocksize(sb, sect_size)) {
                mlog(ML_ERROR, "unable to set blocksize\n");
                return -EIO;
        }

        *bh = sb_getblk(sb, block);
        if (!*bh) {
                mlog_errno(-EIO);
                return -EIO;
        }
        lock_buffer(*bh);
        if (!buffer_dirty(*bh))
                clear_buffer_uptodate(*bh);
        unlock_buffer(*bh);
        ll_rw_block(READ, 1, bh);
        wait_on_buffer(*bh);
        if (!buffer_uptodate(*bh)) {
                mlog_errno(-EIO);
                brelse(*bh);
                *bh = NULL;
                return -EIO;
        }

        return 0;
}

static int ocfs2_mount_volume(struct super_block *sb)
{
        int status = 0;
        int unlock_super = 0;
        struct ocfs2_super *osb = OCFS2_SB(sb);

        mlog_entry_void();

        if (ocfs2_is_hard_readonly(osb))
                goto leave;

        status = ocfs2_dlm_init(osb);
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        status = ocfs2_super_lock(osb, 1);
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }
        unlock_super = 1;

        /* This will load up the node map and add ourselves to it. */
        status = ocfs2_find_slot(osb);
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        /* load all node-local system inodes */
        status = ocfs2_init_local_system_inodes(osb);
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        status = ocfs2_check_volume(osb);
        if (status < 0) {
                mlog_errno(status);
                goto leave;
        }

        status = ocfs2_truncate_log_init(osb);
        if (status < 0)
                mlog_errno(status);

leave:
        if (unlock_super)
                ocfs2_super_unlock(osb, 1);

        mlog_exit(status);
        return status;
}

static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err)
{
        int tmp, hangup_needed = 0;
        struct ocfs2_super *osb = NULL;
        char nodestr[8];

        mlog_entry("(0x%p)\n", sb);

        BUG_ON(!sb);
        osb = OCFS2_SB(sb);
        BUG_ON(!osb);

        debugfs_remove(osb->osb_ctxt);

        /*
         * Flush inode dropping work queue so that deletes are
         * performed while the filesystem is still working
         */
        ocfs2_drop_all_dl_inodes(osb);

        /* Orphan scan should be stopped as early as possible */
        ocfs2_orphan_scan_stop(osb);

        ocfs2_disable_quotas(osb);

        ocfs2_shutdown_local_alloc(osb);

        ocfs2_truncate_log_shutdown(osb);

        /* This will disable recovery and flush any recovery work. */
        ocfs2_recovery_exit(osb);

        ocfs2_journal_shutdown(osb);

        ocfs2_sync_blockdev(sb);

        ocfs2_purge_refcount_trees(osb);

        /* No cluster connection means we've failed during mount, so skip
         * all the steps which depended on that to complete. */
        if (osb->cconn) {
                tmp = ocfs2_super_lock(osb, 1);
                if (tmp < 0) {
                        mlog_errno(tmp);
                        return;
                }
        }

        if (osb->slot_num != OCFS2_INVALID_SLOT)
                ocfs2_put_slot(osb);

        if (osb->cconn)
                ocfs2_super_unlock(osb, 1);

        ocfs2_release_system_inodes(osb);

        /*
         * If we're dismounting due to mount error, mount.ocfs2 will clean
         * up heartbeat.  If we're a local mount, there is no heartbeat.
         * If we failed before we got a uuid_str yet, we can't stop
         * heartbeat.  Otherwise, do it.
         */
        if (!mnt_err && !ocfs2_mount_local(osb) && osb->uuid_str)
                hangup_needed = 1;

        if (osb->cconn)
                ocfs2_dlm_shutdown(osb, hangup_needed);

        ocfs2_blockcheck_stats_debugfs_remove(&osb->osb_ecc_stats);
        debugfs_remove(osb->osb_debug_root);

        if (hangup_needed)
                ocfs2_cluster_hangup(osb->uuid_str, strlen(osb->uuid_str));

        atomic_set(&osb->vol_state, VOLUME_DISMOUNTED);

        if (ocfs2_mount_local(osb))
                snprintf(nodestr, sizeof(nodestr), "local");
        else
                snprintf(nodestr, sizeof(nodestr), "%u", osb->node_num);

        printk(KERN_INFO "ocfs2: Unmounting device (%s) on (node %s)\n",
               osb->dev_str, nodestr);

        ocfs2_delete_osb(osb);
        kfree(osb);
        sb->s_dev = 0;
        sb->s_fs_info = NULL;
}

static int ocfs2_setup_osb_uuid(struct ocfs2_super *osb, const unsigned char *uuid,
                                unsigned uuid_bytes)
{
        int i, ret;
        char *ptr;

        BUG_ON(uuid_bytes != OCFS2_VOL_UUID_LEN);

        osb->uuid_str = kzalloc(OCFS2_VOL_UUID_LEN * 2 + 1, GFP_KERNEL);
        if (osb->uuid_str == NULL)
                return -ENOMEM;

        for (i = 0, ptr = osb->uuid_str; i < OCFS2_VOL_UUID_LEN; i++) {
                /* print with null */
                ret = snprintf(ptr, 3, "%02X", uuid[i]);
                if (ret != 2) /* drop super cleans up */
                        return -EINVAL;
                /* then only advance past the last char */
                ptr += 2;
        }

        return 0;
}

static int ocfs2_initialize_super(struct super_block *sb,
                                  struct buffer_head *bh,
                                  int sector_size,
                                  struct ocfs2_blockcheck_stats *stats)
{
        int status;
        int i, cbits, bbits;
        struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
        struct inode *inode = NULL;
        struct ocfs2_journal *journal;
        __le32 uuid_net_key;
        struct ocfs2_super *osb;

        mlog_entry_void();

        osb = kzalloc(sizeof(struct ocfs2_super), GFP_KERNEL);
        if (!osb) {
                status = -ENOMEM;
                mlog_errno(status);
                goto bail;
        }

        sb->s_fs_info = osb;
        sb->s_op = &ocfs2_sops;
        sb->s_export_op = &ocfs2_export_ops;
        sb->s_qcop = &ocfs2_quotactl_ops;
        sb->dq_op = &ocfs2_quota_operations;
        sb->s_xattr = ocfs2_xattr_handlers;
        sb->s_time_gran = 1;
        sb->s_flags |= MS_NOATIME;
        /* this is needed to support O_LARGEFILE */
        cbits = le32_to_cpu(di->id2.i_super.s_clustersize_bits);
        bbits = le32_to_cpu(di->id2.i_super.s_blocksize_bits);
        sb->s_maxbytes = ocfs2_max_file_offset(bbits, cbits);

        osb->osb_dx_mask = (1 << (cbits - bbits)) - 1;

        for (i = 0; i < 3; i++)
                osb->osb_dx_seed[i] = le32_to_cpu(di->id2.i_super.s_dx_seed[i]);
        osb->osb_dx_seed[3] = le32_to_cpu(di->id2.i_super.s_uuid_hash);

        osb->sb = sb;
        /* Save off for ocfs2_rw_direct */
        osb->s_sectsize_bits = blksize_bits(sector_size);
        BUG_ON(!osb->s_sectsize_bits);

        spin_lock_init(&osb->dc_task_lock);
        init_waitqueue_head(&osb->dc_event);
        osb->dc_work_sequence = 0;
        osb->dc_wake_sequence = 0;
        INIT_LIST_HEAD(&osb->blocked_lock_list);
        osb->blocked_lock_count = 0;
        spin_lock_init(&osb->osb_lock);
        spin_lock_init(&osb->osb_xattr_lock);
        ocfs2_init_inode_steal_slot(osb);

        atomic_set(&osb->alloc_stats.moves, 0);
        atomic_set(&osb->alloc_stats.local_data, 0);
        atomic_set(&osb->alloc_stats.bitmap_data, 0);
        atomic_set(&osb->alloc_stats.bg_allocs, 0);
        atomic_set(&osb->alloc_stats.bg_extends, 0);

        /* Copy the blockcheck stats from the superblock probe */
        osb->osb_ecc_stats = *stats;

        ocfs2_init_node_maps(osb);

        snprintf(osb->dev_str, sizeof(osb->dev_str), "%u,%u",
                 MAJOR(osb->sb->s_dev), MINOR(osb->sb->s_dev));

        ocfs2_orphan_scan_init(osb);

        status = ocfs2_recovery_init(osb);
        if (status) {
                mlog(ML_ERROR, "Unable to initialize recovery state\n");
                mlog_errno(status);
                goto bail;
        }

        init_waitqueue_head(&osb->checkpoint_event);
        atomic_set(&osb->needs_checkpoint, 0);

        osb->s_atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;

        osb->slot_num = OCFS2_INVALID_SLOT;

        osb->s_xattr_inline_size = le16_to_cpu(
                                        di->id2.i_super.s_xattr_inline_size);

        osb->local_alloc_state = OCFS2_LA_UNUSED;
        osb->local_alloc_bh = NULL;
        INIT_DELAYED_WORK(&osb->la_enable_wq, ocfs2_la_enable_worker);

        init_waitqueue_head(&osb->osb_mount_event);

        osb->vol_label = kmalloc(OCFS2_MAX_VOL_LABEL_LEN, GFP_KERNEL);
        if (!osb->vol_label) {
                mlog(ML_ERROR, "unable to alloc vol label\n");
                status = -ENOMEM;
                goto bail;
        }

        osb->max_slots = le16_to_cpu(di->id2.i_super.s_max_slots);
        if (osb->max_slots > OCFS2_MAX_SLOTS || osb->max_slots == 0) {
                mlog(ML_ERROR, "Invalid number of node slots (%u)\n",
                     osb->max_slots);
                status = -EINVAL;
                goto bail;
        }
        mlog(0, "max_slots for this device: %u\n", osb->max_slots);

        osb->slot_recovery_generations =
                kcalloc(osb->max_slots, sizeof(*osb->slot_recovery_generations),
                        GFP_KERNEL);
        if (!osb->slot_recovery_generations) {
                status = -ENOMEM;
                mlog_errno(status);
                goto bail;
        }

        init_waitqueue_head(&osb->osb_wipe_event);
        osb->osb_orphan_wipes = kcalloc(osb->max_slots,
                                        sizeof(*osb->osb_orphan_wipes),
                                        GFP_KERNEL);
        if (!osb->osb_orphan_wipes) {
                status = -ENOMEM;
                mlog_errno(status);
                goto bail;
        }

        osb->osb_rf_lock_tree = RB_ROOT;

        osb->s_feature_compat =
                le32_to_cpu(OCFS2_RAW_SB(di)->s_feature_compat);
        osb->s_feature_ro_compat =
                le32_to_cpu(OCFS2_RAW_SB(di)->s_feature_ro_compat);
        osb->s_feature_incompat =
                le32_to_cpu(OCFS2_RAW_SB(di)->s_feature_incompat);

        if ((i = OCFS2_HAS_INCOMPAT_FEATURE(osb->sb, ~OCFS2_FEATURE_INCOMPAT_SUPP))) {
                mlog(ML_ERROR, "couldn't mount because of unsupported "
                     "optional features (%x).\n", i);
                status = -EINVAL;
                goto bail;
        }
        if (!(osb->sb->s_flags & MS_RDONLY) &&
            (i = OCFS2_HAS_RO_COMPAT_FEATURE(osb->sb, ~OCFS2_FEATURE_RO_COMPAT_SUPP))) {
                mlog(ML_ERROR, "couldn't mount RDWR because of "
                     "unsupported optional features (%x).\n", i);
                status = -EINVAL;
                goto bail;
        }

        if (ocfs2_userspace_stack(osb)) {
                memcpy(osb->osb_cluster_stack,
                       OCFS2_RAW_SB(di)->s_cluster_info.ci_stack,
                       OCFS2_STACK_LABEL_LEN);
                osb->osb_cluster_stack[OCFS2_STACK_LABEL_LEN] = '\0';
                if (strlen(osb->osb_cluster_stack) != OCFS2_STACK_LABEL_LEN) {
                        mlog(ML_ERROR,
                             "couldn't mount because of an invalid "
                             "cluster stack label (%s) \n",
                             osb->osb_cluster_stack);
                        status = -EINVAL;
                        goto bail;
                }
        } else {
                /* The empty string is identical with classic tools that
                 * don't know about s_cluster_info. */
                osb->osb_cluster_stack[0] = '\0';
        }

        get_random_bytes(&osb->s_next_generation, sizeof(u32));

        /* FIXME
         * This should be done in ocfs2_journal_init(), but unknown
         * ordering issues will cause the filesystem to crash.
         * If anyone wants to figure out what part of the code
         * refers to osb->journal before ocfs2_journal_init() is run,
         * be my guest.
         */
        /* initialize our journal structure */

        journal = kzalloc(sizeof(struct ocfs2_journal), GFP_KERNEL);
        if (!journal) {
                mlog(ML_ERROR, "unable to alloc journal\n");
                status = -ENOMEM;
                goto bail;
        }
        osb->journal = journal;
        journal->j_osb = osb;

        atomic_set(&journal->j_num_trans, 0);
        init_rwsem(&journal->j_trans_barrier);
        init_waitqueue_head(&journal->j_checkpointed);
        spin_lock_init(&journal->j_lock);
        journal->j_trans_id = (unsigned long) 1;
        INIT_LIST_HEAD(&journal->j_la_cleanups);
        INIT_WORK(&journal->j_recovery_work, ocfs2_complete_recovery);
        journal->j_state = OCFS2_JOURNAL_FREE;

        INIT_WORK(&osb->dentry_lock_work, ocfs2_drop_dl_inodes);
        osb->dentry_lock_list = NULL;

        /* get some pseudo constants for clustersize bits */
        osb->s_clustersize_bits =
                le32_to_cpu(di->id2.i_super.s_clustersize_bits);
        osb->s_clustersize = 1 << osb->s_clustersize_bits;
        mlog(0, "clusterbits=%d\n", osb->s_clustersize_bits);

        if (osb->s_clustersize < OCFS2_MIN_CLUSTERSIZE ||
            osb->s_clustersize > OCFS2_MAX_CLUSTERSIZE) {
                mlog(ML_ERROR, "Volume has invalid cluster size (%d)\n",
                     osb->s_clustersize);
                status = -EINVAL;
                goto bail;
        }

        if (ocfs2_clusters_to_blocks(osb->sb, le32_to_cpu(di->i_clusters) - 1)
            > (u32)~0UL) {
                mlog(ML_ERROR, "Volume might try to write to blocks beyond "
                     "what jbd can address in 32 bits.\n");
                status = -EINVAL;
                goto bail;
        }

        if (ocfs2_setup_osb_uuid(osb, di->id2.i_super.s_uuid,
                                 sizeof(di->id2.i_super.s_uuid))) {
                mlog(ML_ERROR, "Out of memory trying to setup our uuid.\n");
                status = -ENOMEM;
                goto bail;
        }

        memcpy(&uuid_net_key, di->id2.i_super.s_uuid, sizeof(uuid_net_key));

        strncpy(osb->vol_label, di->id2.i_super.s_label, 63);
        osb->vol_label[63] = '\0';
        osb->root_blkno = le64_to_cpu(di->id2.i_super.s_root_blkno);
        osb->system_dir_blkno = le64_to_cpu(di->id2.i_super.s_system_dir_blkno);
        osb->first_cluster_group_blkno =
                le64_to_cpu(di->id2.i_super.s_first_cluster_group);
        osb->fs_generation = le32_to_cpu(di->i_fs_generation);
        osb->uuid_hash = le32_to_cpu(di->id2.i_super.s_uuid_hash);
        mlog(0, "vol_label: %s\n", osb->vol_label);
        mlog(0, "uuid: %s\n", osb->uuid_str);
        mlog(0, "root_blkno=%llu, system_dir_blkno=%llu\n",
             (unsigned long long)osb->root_blkno,
             (unsigned long long)osb->system_dir_blkno);

        osb->osb_dlm_debug = ocfs2_new_dlm_debug();
        if (!osb->osb_dlm_debug) {
                status = -ENOMEM;
                mlog_errno(status);
                goto bail;
        }

        atomic_set(&osb->vol_state, VOLUME_INIT);

        /* load root, system_dir, and all global system inodes */
        status = ocfs2_init_global_system_inodes(osb);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }

        /*
         * global bitmap
         */
        inode = ocfs2_get_system_file_inode(osb, GLOBAL_BITMAP_SYSTEM_INODE,
                                            OCFS2_INVALID_SLOT);
        if (!inode) {
                status = -EINVAL;
                mlog_errno(status);
                goto bail;
        }

        osb->bitmap_blkno = OCFS2_I(inode)->ip_blkno;
        iput(inode);

        osb->bitmap_cpg = ocfs2_group_bitmap_size(sb) * 8;

        status = ocfs2_init_slot_info(osb);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }

bail:
        mlog_exit(status);
        return status;
}

/*
 * will return: -EAGAIN if it is ok to keep searching for superblocks
 *              -EINVAL if there is a bad superblock
 *              0 on success
 */
static int ocfs2_verify_volume(struct ocfs2_dinode *di,
                               struct buffer_head *bh,
                               u32 blksz,
                               struct ocfs2_blockcheck_stats *stats)
{
        int status = -EAGAIN;

        mlog_entry_void();

        if (memcmp(di->i_signature, OCFS2_SUPER_BLOCK_SIGNATURE,
                   strlen(OCFS2_SUPER_BLOCK_SIGNATURE)) == 0) {
                /* We have to do a raw check of the feature here */
                if (le32_to_cpu(di->id2.i_super.s_feature_incompat) &
                    OCFS2_FEATURE_INCOMPAT_META_ECC) {
                        status = ocfs2_block_check_validate(bh->b_data,
                                                            bh->b_size,
                                                            &di->i_check,
                                                            stats);
                        if (status)
                                goto out;
                }
                status = -EINVAL;
                if ((1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits)) != blksz) {
                        mlog(ML_ERROR, "found superblock with incorrect block "
                             "size: found %u, should be %u\n",
                             1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits),
                               blksz);
                } else if (le16_to_cpu(di->id2.i_super.s_major_rev_level) !=
                           OCFS2_MAJOR_REV_LEVEL ||
                           le16_to_cpu(di->id2.i_super.s_minor_rev_level) !=
                           OCFS2_MINOR_REV_LEVEL) {
                        mlog(ML_ERROR, "found superblock with bad version: "
                             "found %u.%u, should be %u.%u\n",
                             le16_to_cpu(di->id2.i_super.s_major_rev_level),
                             le16_to_cpu(di->id2.i_super.s_minor_rev_level),
                             OCFS2_MAJOR_REV_LEVEL,
                             OCFS2_MINOR_REV_LEVEL);
                } else if (bh->b_blocknr != le64_to_cpu(di->i_blkno)) {
                        mlog(ML_ERROR, "bad block number on superblock: "
                             "found %llu, should be %llu\n",
                             (unsigned long long)le64_to_cpu(di->i_blkno),
                             (unsigned long long)bh->b_blocknr);
                } else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
                            le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
                        mlog(ML_ERROR, "bad cluster size found: %u\n",
                             1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
                } else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {
                        mlog(ML_ERROR, "bad root_blkno: 0\n");
                } else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {
                        mlog(ML_ERROR, "bad system_dir_blkno: 0\n");
                } else if (le16_to_cpu(di->id2.i_super.s_max_slots) > OCFS2_MAX_SLOTS) {
                        mlog(ML_ERROR,
                             "Superblock slots found greater than file system "
                             "maximum: found %u, max %u\n",
                             le16_to_cpu(di->id2.i_super.s_max_slots),
                             OCFS2_MAX_SLOTS);
                } else {
                        /* found it! */
                        status = 0;
                }
        }

out:
        mlog_exit(status);
        return status;
}

static int ocfs2_check_volume(struct ocfs2_super *osb)
{
        int status;
        int dirty;
        int local;
        struct ocfs2_dinode *local_alloc = NULL; /* only used if we
                                                  * recover
                                                  * ourselves. */

        mlog_entry_void();

        /* Init our journal object. */
        status = ocfs2_journal_init(osb->journal, &dirty);
        if (status < 0) {
                mlog(ML_ERROR, "Could not initialize journal!\n");
                goto finally;
        }

        /* If the journal was unmounted cleanly then we don't want to
         * recover anything. Otherwise, journal_load will do that
         * dirty work for us :) */
        if (!dirty) {
                status = ocfs2_journal_wipe(osb->journal, 0);
                if (status < 0) {
                        mlog_errno(status);
                        goto finally;
                }
        } else {
                mlog(ML_NOTICE, "File system was not unmounted cleanly, "
                     "recovering volume.\n");
        }

        local = ocfs2_mount_local(osb);

        /* will play back anything left in the journal. */
        status = ocfs2_journal_load(osb->journal, local, dirty);
        if (status < 0) {
                mlog(ML_ERROR, "ocfs2 journal load failed! %d\n", status);
                goto finally;
        }

        if (dirty) {
                /* recover my local alloc if we didn't unmount cleanly. */
                status = ocfs2_begin_local_alloc_recovery(osb,
                                                          osb->slot_num,
                                                          &local_alloc);
                if (status < 0) {
                        mlog_errno(status);
                        goto finally;
                }
                /* we complete the recovery process after we've marked
                 * ourselves as mounted. */
        }

        mlog(0, "Journal loaded.\n");

        status = ocfs2_load_local_alloc(osb);
        if (status < 0) {
                mlog_errno(status);
                goto finally;
        }

        if (dirty) {
                /* Recovery will be completed after we've mounted the
                 * rest of the volume. */
                osb->dirty = 1;
                osb->local_alloc_copy = local_alloc;
                local_alloc = NULL;
        }

        /* go through each journal, trylock it and if you get the
         * lock, and it's marked as dirty, set the bit in the recover
         * map and launch a recovery thread for it. */
        status = ocfs2_mark_dead_nodes(osb);
        if (status < 0) {
                mlog_errno(status);
                goto finally;
        }

        status = ocfs2_compute_replay_slots(osb);
        if (status < 0)
                mlog_errno(status);

finally:
        if (local_alloc)
                kfree(local_alloc);

        mlog_exit(status);
        return status;
}

/*
 * The routine gets called from dismount or close whenever a dismount on
 * volume is requested and the osb open count becomes 1.
 * It will remove the osb from the global list and also free up all the
 * initialized resources and fileobject.
 */
static void ocfs2_delete_osb(struct ocfs2_super *osb)
{
        mlog_entry_void();

        /* This function assumes that the caller has the main osb resource */

        ocfs2_free_slot_info(osb);

        kfree(osb->osb_orphan_wipes);
        kfree(osb->slot_recovery_generations);
        /* FIXME
         * This belongs in journal shutdown, but because we have to
         * allocate osb->journal at the start of ocfs2_initalize_osb(),
         * we free it here.
         */
        kfree(osb->journal);
        if (osb->local_alloc_copy)
                kfree(osb->local_alloc_copy);
        kfree(osb->uuid_str);
        ocfs2_put_dlm_debug(osb->osb_dlm_debug);
        memset(osb, 0, sizeof(struct ocfs2_super));

        mlog_exit_void();
}

/* Put OCFS2 into a readonly state, or (if the user specifies it),
 * panic(). We do not support continue-on-error operation. */
static void ocfs2_handle_error(struct super_block *sb)
{
        struct ocfs2_super *osb = OCFS2_SB(sb);

        if (osb->s_mount_opt & OCFS2_MOUNT_ERRORS_PANIC)
                panic("OCFS2: (device %s): panic forced after error\n",
                      sb->s_id);

        ocfs2_set_osb_flag(osb, OCFS2_OSB_ERROR_FS);

        if (sb->s_flags & MS_RDONLY &&
            (ocfs2_is_soft_readonly(osb) ||
             ocfs2_is_hard_readonly(osb)))
                return;

        printk(KERN_CRIT "File system is now read-only due to the potential "
               "of on-disk corruption. Please run fsck.ocfs2 once the file "
               "system is unmounted.\n");
        sb->s_flags |= MS_RDONLY;
        ocfs2_set_ro_flag(osb, 0);
}

static char error_buf[1024];

void __ocfs2_error(struct super_block *sb,
                   const char *function,
                   const char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        vsnprintf(error_buf, sizeof(error_buf), fmt, args);
        va_end(args);

        /* Not using mlog here because we want to show the actual
         * function the error came from. */
        printk(KERN_CRIT "OCFS2: ERROR (device %s): %s: %s\n",
               sb->s_id, function, error_buf);

        ocfs2_handle_error(sb);
}

/* Handle critical errors. This is intentionally more drastic than
 * ocfs2_handle_error, so we only use for things like journal errors,
 * etc. */
void __ocfs2_abort(struct super_block* sb,
                   const char *function,
                   const char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        vsnprintf(error_buf, sizeof(error_buf), fmt, args);
        va_end(args);

        printk(KERN_CRIT "OCFS2: abort (device %s): %s: %s\n",
               sb->s_id, function, error_buf);

        /* We don't have the cluster support yet to go straight to
         * hard readonly in here. Until then, we want to keep
         * ocfs2_abort() so that we can at least mark critical
         * errors.
         *
         * TODO: This should abort the journal and alert other nodes
         * that our slot needs recovery. */

        /* Force a panic(). This stinks, but it's better than letting
         * things continue without having a proper hard readonly
         * here. */
        if (!ocfs2_mount_local(OCFS2_SB(sb)))
                OCFS2_SB(sb)->s_mount_opt |= OCFS2_MOUNT_ERRORS_PANIC;
        ocfs2_handle_error(sb);
}

module_init(ocfs2_init);
module_exit(ocfs2_exit);