/*
 *  Implementation of operations over local quota file
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/quota.h>
#include <linux/quotaops.h>
#include <linux/module.h>

#include <cluster/masklog.h>

#include "ocfs2_fs.h"
#include "ocfs2.h"
#include "inode.h"
#include "alloc.h"
#include "file.h"
#include "buffer_head_io.h"
#include "journal.h"
#include "sysfile.h"
#include "dlmglue.h"
#include "quota.h"
#include "uptodate.h"
#include "super.h"
#include "ocfs2_trace.h"

/* Number of local quota structures per block */
static inline unsigned int ol_quota_entries_per_block(struct super_block *sb)
{
        return ((sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE) /
                sizeof(struct ocfs2_local_disk_dqblk));
}

/* Number of blocks with entries in one chunk */
static inline unsigned int ol_chunk_blocks(struct super_block *sb)
{
        return ((sb->s_blocksize - sizeof(struct ocfs2_local_disk_chunk) -
                 OCFS2_QBLK_RESERVED_SPACE) << 3) /
               ol_quota_entries_per_block(sb);
}

/* Number of entries in a chunk bitmap */
static unsigned int ol_chunk_entries(struct super_block *sb)
{
        return ol_chunk_blocks(sb) * ol_quota_entries_per_block(sb);
}

/* Offset of the chunk in quota file */
static unsigned int ol_quota_chunk_block(struct super_block *sb, int c)
{
        /* 1 block for local quota file info, 1 block per chunk for chunk info */
        return 1 + (ol_chunk_blocks(sb) + 1) * c;
}

static unsigned int ol_dqblk_block(struct super_block *sb, int c, int off)
{
        int epb = ol_quota_entries_per_block(sb);

        return ol_quota_chunk_block(sb, c) + 1 + off / epb;
}

static unsigned int ol_dqblk_block_off(struct super_block *sb, int c, int off)
{
        int epb = ol_quota_entries_per_block(sb);

        return (off % epb) * sizeof(struct ocfs2_local_disk_dqblk);
}

/* Offset of the dquot structure in the quota file */
static loff_t ol_dqblk_off(struct super_block *sb, int c, int off)
{
        return (ol_dqblk_block(sb, c, off) << sb->s_blocksize_bits) +
               ol_dqblk_block_off(sb, c, off);
}

/* Compute block number from given offset */
static inline unsigned int ol_dqblk_file_block(struct super_block *sb, loff_t off)
{
        return off >> sb->s_blocksize_bits;
}

static inline unsigned int ol_dqblk_block_offset(struct super_block *sb, loff_t off)
{
        return off & ((1 << sb->s_blocksize_bits) - 1);
}

/* Compute offset in the chunk of a structure with the given offset */
static int ol_dqblk_chunk_off(struct super_block *sb, int c, loff_t off)
{
        int epb = ol_quota_entries_per_block(sb);

        return ((off >> sb->s_blocksize_bits) -
                        ol_quota_chunk_block(sb, c) - 1) * epb
               + ((unsigned int)(off & ((1 << sb->s_blocksize_bits) - 1))) /
                 sizeof(struct ocfs2_local_disk_dqblk);
}

/* Write bufferhead into the fs */
static int ocfs2_modify_bh(struct inode *inode, struct buffer_head *bh,
                void (*modify)(struct buffer_head *, void *), void *private)
{
        struct super_block *sb = inode->i_sb;
        handle_t *handle;
        int status;

        handle = ocfs2_start_trans(OCFS2_SB(sb),
                                   OCFS2_QUOTA_BLOCK_UPDATE_CREDITS);
        if (IS_ERR(handle)) {
                status = PTR_ERR(handle);
                mlog_errno(status);
                return status;
        }
        status = ocfs2_journal_access_dq(handle, INODE_CACHE(inode), bh,
                                         OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                ocfs2_commit_trans(OCFS2_SB(sb), handle);
                return status;
        }
        lock_buffer(bh);
        modify(bh, private);
        unlock_buffer(bh);
        ocfs2_journal_dirty(handle, bh);

        status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
        if (status < 0) {
                mlog_errno(status);
                return status;
        }
        return 0;
}

/*
 * Read quota block from a given logical offset.
 *
 * This function acquires ip_alloc_sem and thus it must not be called with a
 * transaction started.
 */
static int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
                                  struct buffer_head **bh)
{
        int rc = 0;
        struct buffer_head *tmp = *bh;

        if (i_size_read(inode) >> inode->i_sb->s_blocksize_bits <= v_block) {
                ocfs2_error(inode->i_sb,
                            "Quota file %llu is probably corrupted! Requested "
                            "to read block %Lu but file has size only %Lu\n",
                            (unsigned long long)OCFS2_I(inode)->ip_blkno,
                            (unsigned long long)v_block,
                            (unsigned long long)i_size_read(inode));
                return -EIO;
        }
        rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, 0,
                                    ocfs2_validate_quota_block);
        if (rc)
                mlog_errno(rc);

        /* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
        if (!rc && !*bh)
                *bh = tmp;

        return rc;
}

/* Check whether we understand format of quota files */
static int ocfs2_local_check_quota_file(struct super_block *sb, int type)
{
        unsigned int lmagics[MAXQUOTAS] = OCFS2_LOCAL_QMAGICS;
        unsigned int lversions[MAXQUOTAS] = OCFS2_LOCAL_QVERSIONS;
        unsigned int gmagics[MAXQUOTAS] = OCFS2_GLOBAL_QMAGICS;
        unsigned int gversions[MAXQUOTAS] = OCFS2_GLOBAL_QVERSIONS;
        unsigned int ino[MAXQUOTAS] = { USER_QUOTA_SYSTEM_INODE,
                                        GROUP_QUOTA_SYSTEM_INODE };
        struct buffer_head *bh = NULL;
        struct inode *linode = sb_dqopt(sb)->files[type];
        struct inode *ginode = NULL;
        struct ocfs2_disk_dqheader *dqhead;
        int status, ret = 0;

        /* First check whether we understand local quota file */
        status = ocfs2_read_quota_block(linode, 0, &bh);
        if (status) {
                mlog_errno(status);
                mlog(ML_ERROR, "failed to read quota file header (type=%d)\n",
                        type);
                goto out_err;
        }
        dqhead = (struct ocfs2_disk_dqheader *)(bh->b_data);
        if (le32_to_cpu(dqhead->dqh_magic) != lmagics[type]) {
                mlog(ML_ERROR, "quota file magic does not match (%u != %u),"
                        " type=%d\n", le32_to_cpu(dqhead->dqh_magic),
                        lmagics[type], type);
                goto out_err;
        }
        if (le32_to_cpu(dqhead->dqh_version) != lversions[type]) {
                mlog(ML_ERROR, "quota file version does not match (%u != %u),"
                        " type=%d\n", le32_to_cpu(dqhead->dqh_version),
                        lversions[type], type);
                goto out_err;
        }
        brelse(bh);
        bh = NULL;

        /* Next check whether we understand global quota file */
        ginode = ocfs2_get_system_file_inode(OCFS2_SB(sb), ino[type],
                                                OCFS2_INVALID_SLOT);
        if (!ginode) {
                mlog(ML_ERROR, "cannot get global quota file inode "
                                "(type=%d)\n", type);
                goto out_err;
        }
        /* Since the header is read only, we don't care about locking */
        status = ocfs2_read_quota_block(ginode, 0, &bh);
        if (status) {
                mlog_errno(status);
                mlog(ML_ERROR, "failed to read global quota file header "
                                "(type=%d)\n", type);
                goto out_err;
        }
        dqhead = (struct ocfs2_disk_dqheader *)(bh->b_data);
        if (le32_to_cpu(dqhead->dqh_magic) != gmagics[type]) {
                mlog(ML_ERROR, "global quota file magic does not match "
                        "(%u != %u), type=%d\n",
                        le32_to_cpu(dqhead->dqh_magic), gmagics[type], type);
                goto out_err;
        }
        if (le32_to_cpu(dqhead->dqh_version) != gversions[type]) {
                mlog(ML_ERROR, "global quota file version does not match "
                        "(%u != %u), type=%d\n",
                        le32_to_cpu(dqhead->dqh_version), gversions[type],
                        type);
                goto out_err;
        }

        ret = 1;
out_err:
        brelse(bh);
        iput(ginode);
        return ret;
}

/* Release given list of quota file chunks */
static void ocfs2_release_local_quota_bitmaps(struct list_head *head)
{
        struct ocfs2_quota_chunk *pos, *next;

        list_for_each_entry_safe(pos, next, head, qc_chunk) {
                list_del(&pos->qc_chunk);
                brelse(pos->qc_headerbh);
                kmem_cache_free(ocfs2_qf_chunk_cachep, pos);
        }
}

/* Load quota bitmaps into memory */
static int ocfs2_load_local_quota_bitmaps(struct inode *inode,
                        struct ocfs2_local_disk_dqinfo *ldinfo,
                        struct list_head *head)
{
        struct ocfs2_quota_chunk *newchunk;
        int i, status;

        INIT_LIST_HEAD(head);
        for (i = 0; i < le32_to_cpu(ldinfo->dqi_chunks); i++) {
                newchunk = kmem_cache_alloc(ocfs2_qf_chunk_cachep, GFP_NOFS);
                if (!newchunk) {
                        ocfs2_release_local_quota_bitmaps(head);
                        return -ENOMEM;
                }
                newchunk->qc_num = i;
                newchunk->qc_headerbh = NULL;
                status = ocfs2_read_quota_block(inode,
                                ol_quota_chunk_block(inode->i_sb, i),
                                &newchunk->qc_headerbh);
                if (status) {
                        mlog_errno(status);
                        kmem_cache_free(ocfs2_qf_chunk_cachep, newchunk);
                        ocfs2_release_local_quota_bitmaps(head);
                        return status;
                }
                list_add_tail(&newchunk->qc_chunk, head);
        }
        return 0;
}

static void olq_update_info(struct buffer_head *bh, void *private)
{
        struct mem_dqinfo *info = private;
        struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
        struct ocfs2_local_disk_dqinfo *ldinfo;

        ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
                                                OCFS2_LOCAL_INFO_OFF);
        spin_lock(&dq_data_lock);
        ldinfo->dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
        ldinfo->dqi_chunks = cpu_to_le32(oinfo->dqi_chunks);
        ldinfo->dqi_blocks = cpu_to_le32(oinfo->dqi_blocks);
        spin_unlock(&dq_data_lock);
}

static int ocfs2_add_recovery_chunk(struct super_block *sb,
                                    struct ocfs2_local_disk_chunk *dchunk,
                                    int chunk,
                                    struct list_head *head)
{
        struct ocfs2_recovery_chunk *rc;

        rc = kmalloc(sizeof(struct ocfs2_recovery_chunk), GFP_NOFS);
        if (!rc)
                return -ENOMEM;
        rc->rc_chunk = chunk;
        rc->rc_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
        if (!rc->rc_bitmap) {
                kfree(rc);
                return -ENOMEM;
        }
        memcpy(rc->rc_bitmap, dchunk->dqc_bitmap,
               (ol_chunk_entries(sb) + 7) >> 3);
        list_add_tail(&rc->rc_list, head);
        return 0;
}

static void free_recovery_list(struct list_head *head)
{
        struct ocfs2_recovery_chunk *next;
        struct ocfs2_recovery_chunk *rchunk;

        list_for_each_entry_safe(rchunk, next, head, rc_list) {
                list_del(&rchunk->rc_list);
                kfree(rchunk->rc_bitmap);
                kfree(rchunk);
        }
}

void ocfs2_free_quota_recovery(struct ocfs2_quota_recovery *rec)
{
        int type;

        for (type = 0; type < MAXQUOTAS; type++)
                free_recovery_list(&(rec->r_list[type]));
        kfree(rec);
}

/* Load entries in our quota file we have to recover*/
static int ocfs2_recovery_load_quota(struct inode *lqinode,
                                     struct ocfs2_local_disk_dqinfo *ldinfo,
                                     int type,
                                     struct list_head *head)
{
        struct super_block *sb = lqinode->i_sb;
        struct buffer_head *hbh;
        struct ocfs2_local_disk_chunk *dchunk;
        int i, chunks = le32_to_cpu(ldinfo->dqi_chunks);
        int status = 0;

        for (i = 0; i < chunks; i++) {
                hbh = NULL;
                status = ocfs2_read_quota_block(lqinode,
                                                ol_quota_chunk_block(sb, i),
                                                &hbh);
                if (status) {
                        mlog_errno(status);
                        break;
                }
                dchunk = (struct ocfs2_local_disk_chunk *)hbh->b_data;
                if (le32_to_cpu(dchunk->dqc_free) < ol_chunk_entries(sb))
                        status = ocfs2_add_recovery_chunk(sb, dchunk, i, head);
                brelse(hbh);
                if (status < 0)
                        break;
        }
        if (status < 0)
                free_recovery_list(head);
        return status;
}

static struct ocfs2_quota_recovery *ocfs2_alloc_quota_recovery(void)
{
        int type;
        struct ocfs2_quota_recovery *rec;

        rec = kmalloc(sizeof(struct ocfs2_quota_recovery), GFP_NOFS);
        if (!rec)
                return NULL;
        for (type = 0; type < MAXQUOTAS; type++)
                INIT_LIST_HEAD(&(rec->r_list[type]));
        return rec;
}

/* Load information we need for quota recovery into memory */
struct ocfs2_quota_recovery *ocfs2_begin_quota_recovery(
                                                struct ocfs2_super *osb,
                                                int slot_num)
{
        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 };
        struct super_block *sb = osb->sb;
        struct ocfs2_local_disk_dqinfo *ldinfo;
        struct inode *lqinode;
        struct buffer_head *bh;
        int type;
        int status = 0;
        struct ocfs2_quota_recovery *rec;

        mlog(ML_NOTICE, "Beginning quota recovery in slot %u\n", slot_num);
        rec = ocfs2_alloc_quota_recovery();
        if (!rec)
                return ERR_PTR(-ENOMEM);
        /* First init... */

        for (type = 0; type < MAXQUOTAS; type++) {
                if (!OCFS2_HAS_RO_COMPAT_FEATURE(sb, feature[type]))
                        continue;
                /* At this point, journal of the slot is already replayed so
                 * we can trust metadata and data of the quota file */
                lqinode = ocfs2_get_system_file_inode(osb, ino[type], slot_num);
                if (!lqinode) {
                        status = -ENOENT;
                        goto out;
                }
                status = ocfs2_inode_lock_full(lqinode, NULL, 1,
                                               OCFS2_META_LOCK_RECOVERY);
                if (status < 0) {
                        mlog_errno(status);
                        goto out_put;
                }
                /* Now read local header */
                bh = NULL;
                status = ocfs2_read_quota_block(lqinode, 0, &bh);
                if (status) {
                        mlog_errno(status);
                        mlog(ML_ERROR, "failed to read quota file info header "
                                "(slot=%d type=%d)\n", slot_num, type);
                        goto out_lock;
                }
                ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
                                                        OCFS2_LOCAL_INFO_OFF);
                status = ocfs2_recovery_load_quota(lqinode, ldinfo, type,
                                                   &rec->r_list[type]);
                brelse(bh);
out_lock:
                ocfs2_inode_unlock(lqinode, 1);
out_put:
                iput(lqinode);
                if (status < 0)
                        break;
        }
out:
        if (status < 0) {
                ocfs2_free_quota_recovery(rec);
                rec = ERR_PTR(status);
        }
        return rec;
}

/* Sync changes in local quota file into global quota file and
 * reinitialize local quota file.
 * The function expects local quota file to be already locked and
 * dqonoff_mutex locked. */
static int ocfs2_recover_local_quota_file(struct inode *lqinode,
                                          int type,
                                          struct ocfs2_quota_recovery *rec)
{
        struct super_block *sb = lqinode->i_sb;
        struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
        struct ocfs2_local_disk_chunk *dchunk;
        struct ocfs2_local_disk_dqblk *dqblk;
        struct dquot *dquot;
        handle_t *handle;
        struct buffer_head *hbh = NULL, *qbh = NULL;
        int status = 0;
        int bit, chunk;
        struct ocfs2_recovery_chunk *rchunk, *next;
        qsize_t spacechange, inodechange;

        trace_ocfs2_recover_local_quota_file((unsigned long)lqinode->i_ino, type);

        list_for_each_entry_safe(rchunk, next, &(rec->r_list[type]), rc_list) {
                chunk = rchunk->rc_chunk;
                hbh = NULL;
                status = ocfs2_read_quota_block(lqinode,
                                                ol_quota_chunk_block(sb, chunk),
                                                &hbh);
                if (status) {
                        mlog_errno(status);
                        break;
                }
                dchunk = (struct ocfs2_local_disk_chunk *)hbh->b_data;
                for_each_set_bit(bit, rchunk->rc_bitmap, ol_chunk_entries(sb)) {
                        qbh = NULL;
                        status = ocfs2_read_quota_block(lqinode,
                                                ol_dqblk_block(sb, chunk, bit),
                                                &qbh);
                        if (status) {
                                mlog_errno(status);
                                break;
                        }
                        dqblk = (struct ocfs2_local_disk_dqblk *)(qbh->b_data +
                                ol_dqblk_block_off(sb, chunk, bit));
                        dquot = dqget(sb, le64_to_cpu(dqblk->dqb_id), type);
                        if (!dquot) {
                                status = -EIO;
                                mlog(ML_ERROR, "Failed to get quota structure "
                                     "for id %u, type %d. Cannot finish quota "
                                     "file recovery.\n",
                                     (unsigned)le64_to_cpu(dqblk->dqb_id),
                                     type);
                                goto out_put_bh;
                        }
                        status = ocfs2_lock_global_qf(oinfo, 1);
                        if (status < 0) {
                                mlog_errno(status);
                                goto out_put_dquot;
                        }

                        handle = ocfs2_start_trans(OCFS2_SB(sb),
                                                   OCFS2_QSYNC_CREDITS);
                        if (IS_ERR(handle)) {
                                status = PTR_ERR(handle);
                                mlog_errno(status);
                                goto out_drop_lock;
                        }
                        mutex_lock(&sb_dqopt(sb)->dqio_mutex);
                        spin_lock(&dq_data_lock);
                        /* Add usage from quota entry into quota changes
                         * of our node. Auxiliary variables are important
                         * due to signedness */
                        spacechange = le64_to_cpu(dqblk->dqb_spacemod);
                        inodechange = le64_to_cpu(dqblk->dqb_inodemod);
                        dquot->dq_dqb.dqb_curspace += spacechange;
                        dquot->dq_dqb.dqb_curinodes += inodechange;
                        spin_unlock(&dq_data_lock);
                        /* We want to drop reference held by the crashed
                         * node. Since we have our own reference we know
                         * global structure actually won't be freed. */
                        status = ocfs2_global_release_dquot(dquot);
                        if (status < 0) {
                                mlog_errno(status);
                                goto out_commit;
                        }
                        /* Release local quota file entry */
                        status = ocfs2_journal_access_dq(handle,
                                        INODE_CACHE(lqinode),
                                        qbh, OCFS2_JOURNAL_ACCESS_WRITE);
                        if (status < 0) {
                                mlog_errno(status);
                                goto out_commit;
                        }
                        lock_buffer(qbh);
                        WARN_ON(!ocfs2_test_bit(bit, dchunk->dqc_bitmap));
                        ocfs2_clear_bit(bit, dchunk->dqc_bitmap);
                        le32_add_cpu(&dchunk->dqc_free, 1);
                        unlock_buffer(qbh);
                        ocfs2_journal_dirty(handle, qbh);
out_commit:
                        mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
                        ocfs2_commit_trans(OCFS2_SB(sb), handle);
out_drop_lock:
                        ocfs2_unlock_global_qf(oinfo, 1);
out_put_dquot:
                        dqput(dquot);
out_put_bh:
                        brelse(qbh);
                        if (status < 0)
                                break;
                }
                brelse(hbh);
                list_del(&rchunk->rc_list);
                kfree(rchunk->rc_bitmap);
                kfree(rchunk);
                if (status < 0)
                        break;
        }
        if (status < 0)
                free_recovery_list(&(rec->r_list[type]));
        if (status)
                mlog_errno(status);
        return status;
}

/* Recover local quota files for given node different from us */
int ocfs2_finish_quota_recovery(struct ocfs2_super *osb,
                                struct ocfs2_quota_recovery *rec,
                                int slot_num)
{
        unsigned int ino[MAXQUOTAS] = { LOCAL_USER_QUOTA_SYSTEM_INODE,
                                        LOCAL_GROUP_QUOTA_SYSTEM_INODE };
        struct super_block *sb = osb->sb;
        struct ocfs2_local_disk_dqinfo *ldinfo;
        struct buffer_head *bh;
        handle_t *handle;
        int type;
        int status = 0;
        struct inode *lqinode;
        unsigned int flags;

        mlog(ML_NOTICE, "Finishing quota recovery in slot %u\n", slot_num);
        mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
        for (type = 0; type < MAXQUOTAS; type++) {
                if (list_empty(&(rec->r_list[type])))
                        continue;
                trace_ocfs2_finish_quota_recovery(slot_num);
                lqinode = ocfs2_get_system_file_inode(osb, ino[type], slot_num);
                if (!lqinode) {
                        status = -ENOENT;
                        goto out;
                }
                status = ocfs2_inode_lock_full(lqinode, NULL, 1,
                                                       OCFS2_META_LOCK_NOQUEUE);
                /* Someone else is holding the lock? Then he must be
                 * doing the recovery. Just skip the file... */
                if (status == -EAGAIN) {
                        mlog(ML_NOTICE, "skipping quota recovery for slot %d "
                             "because quota file is locked.\n", slot_num);
                        status = 0;
                        goto out_put;
                } else if (status < 0) {
                        mlog_errno(status);
                        goto out_put;
                }
                /* Now read local header */
                bh = NULL;
                status = ocfs2_read_quota_block(lqinode, 0, &bh);
                if (status) {
                        mlog_errno(status);
                        mlog(ML_ERROR, "failed to read quota file info header "
                                "(slot=%d type=%d)\n", slot_num, type);
                        goto out_lock;
                }
                ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
                                                        OCFS2_LOCAL_INFO_OFF);
                /* Is recovery still needed? */
                flags = le32_to_cpu(ldinfo->dqi_flags);
                if (!(flags & OLQF_CLEAN))
                        status = ocfs2_recover_local_quota_file(lqinode,
                                                                type,
                                                                rec);
                /* We don't want to mark file as clean when it is actually
                 * active */
                if (slot_num == osb->slot_num)
                        goto out_bh;
                /* Mark quota file as clean if we are recovering quota file of
                 * some other node. */
                handle = ocfs2_start_trans(osb,
                                           OCFS2_LOCAL_QINFO_WRITE_CREDITS);
                if (IS_ERR(handle)) {
                        status = PTR_ERR(handle);
                        mlog_errno(status);
                        goto out_bh;
                }
                status = ocfs2_journal_access_dq(handle, INODE_CACHE(lqinode),
                                                 bh,
                                                 OCFS2_JOURNAL_ACCESS_WRITE);
                if (status < 0) {
                        mlog_errno(status);
                        goto out_trans;
                }
                lock_buffer(bh);
                ldinfo->dqi_flags = cpu_to_le32(flags | OLQF_CLEAN);
                unlock_buffer(bh);
                ocfs2_journal_dirty(handle, bh);
out_trans:
                ocfs2_commit_trans(osb, handle);
out_bh:
                brelse(bh);
out_lock:
                ocfs2_inode_unlock(lqinode, 1);
out_put:
                iput(lqinode);
                if (status < 0)
                        break;
        }
out:
        mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
        kfree(rec);
        return status;
}

/* Read information header from quota file */
static int ocfs2_local_read_info(struct super_block *sb, int type)
{
        struct ocfs2_local_disk_dqinfo *ldinfo;
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct ocfs2_mem_dqinfo *oinfo;
        struct inode *lqinode = sb_dqopt(sb)->files[type];
        int status;
        struct buffer_head *bh = NULL;
        struct ocfs2_quota_recovery *rec;
        int locked = 0;

        /* We don't need the lock and we have to acquire quota file locks
         * which will later depend on this lock */
        mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
        info->dqi_maxblimit = 0x7fffffffffffffffLL;
        info->dqi_maxilimit = 0x7fffffffffffffffLL;
        oinfo = kmalloc(sizeof(struct ocfs2_mem_dqinfo), GFP_NOFS);
        if (!oinfo) {
                mlog(ML_ERROR, "failed to allocate memory for ocfs2 quota"
                               " info.");
                goto out_err;
        }
        info->dqi_priv = oinfo;
        oinfo->dqi_type = type;
        INIT_LIST_HEAD(&oinfo->dqi_chunk);
        oinfo->dqi_rec = NULL;
        oinfo->dqi_lqi_bh = NULL;
        oinfo->dqi_libh = NULL;

        status = ocfs2_global_read_info(sb, type);
        if (status < 0)
                goto out_err;

        status = ocfs2_inode_lock(lqinode, &oinfo->dqi_lqi_bh, 1);
        if (status < 0) {
                mlog_errno(status);
                goto out_err;
        }
        locked = 1;

        /* Now read local header */
        status = ocfs2_read_quota_block(lqinode, 0, &bh);
        if (status) {
                mlog_errno(status);
                mlog(ML_ERROR, "failed to read quota file info header "
                        "(type=%d)\n", type);
                goto out_err;
        }
        ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
                                                OCFS2_LOCAL_INFO_OFF);
        info->dqi_flags = le32_to_cpu(ldinfo->dqi_flags);
        oinfo->dqi_chunks = le32_to_cpu(ldinfo->dqi_chunks);
        oinfo->dqi_blocks = le32_to_cpu(ldinfo->dqi_blocks);
        oinfo->dqi_libh = bh;

        /* We crashed when using local quota file? */
        if (!(info->dqi_flags & OLQF_CLEAN)) {
                rec = OCFS2_SB(sb)->quota_rec;
                if (!rec) {
                        rec = ocfs2_alloc_quota_recovery();
                        if (!rec) {
                                status = -ENOMEM;
                                mlog_errno(status);
                                goto out_err;
                        }
                        OCFS2_SB(sb)->quota_rec = rec;
                }

                status = ocfs2_recovery_load_quota(lqinode, ldinfo, type,
                                                   &rec->r_list[type]);
                if (status < 0) {
                        mlog_errno(status);
                        goto out_err;
                }
        }

        status = ocfs2_load_local_quota_bitmaps(lqinode,
                                                ldinfo,
                                                &oinfo->dqi_chunk);
        if (status < 0) {
                mlog_errno(status);
                goto out_err;
        }

        /* Now mark quota file as used */
        info->dqi_flags &= ~OLQF_CLEAN;
        status = ocfs2_modify_bh(lqinode, bh, olq_update_info, info);
        if (status < 0) {
                mlog_errno(status);
                goto out_err;
        }

        mutex_lock(&sb_dqopt(sb)->dqio_mutex);
        return 0;
out_err:
        if (oinfo) {
                iput(oinfo->dqi_gqinode);
                ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
                ocfs2_lock_res_free(&oinfo->dqi_gqlock);
                brelse(oinfo->dqi_lqi_bh);
                if (locked)
                        ocfs2_inode_unlock(lqinode, 1);
                ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);
                kfree(oinfo);
        }
        brelse(bh);
        mutex_lock(&sb_dqopt(sb)->dqio_mutex);
        return -1;
}

/* Write local info to quota file */
static int ocfs2_local_write_info(struct super_block *sb, int type)
{
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct buffer_head *bh = ((struct ocfs2_mem_dqinfo *)info->dqi_priv)
                                                ->dqi_libh;
        int status;

        status = ocfs2_modify_bh(sb_dqopt(sb)->files[type], bh, olq_update_info,
                                 info);
        if (status < 0) {
                mlog_errno(status);
                return -1;
        }

        return 0;
}

/* Release info from memory */
static int ocfs2_local_free_info(struct super_block *sb, int type)
{
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
        struct ocfs2_quota_chunk *chunk;
        struct ocfs2_local_disk_chunk *dchunk;
        int mark_clean = 1, len;
        int status;

        iput(oinfo->dqi_gqinode);
        ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
        ocfs2_lock_res_free(&oinfo->dqi_gqlock);
        list_for_each_entry(chunk, &oinfo->dqi_chunk, qc_chunk) {
                dchunk = (struct ocfs2_local_disk_chunk *)
                                        (chunk->qc_headerbh->b_data);
                if (chunk->qc_num < oinfo->dqi_chunks - 1) {
                        len = ol_chunk_entries(sb);
                } else {
                        len = (oinfo->dqi_blocks -
                               ol_quota_chunk_block(sb, chunk->qc_num) - 1)
                              * ol_quota_entries_per_block(sb);
                }
                /* Not all entries free? Bug! */
                if (le32_to_cpu(dchunk->dqc_free) != len) {
                        mlog(ML_ERROR, "releasing quota file with used "
                                        "entries (type=%d)\n", type);
                        mark_clean = 0;
                }
        }
        ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);

        /* dqonoff_mutex protects us against racing with recovery thread... */
        if (oinfo->dqi_rec) {
                ocfs2_free_quota_recovery(oinfo->dqi_rec);
                mark_clean = 0;
        }

        if (!mark_clean)
                goto out;

        /* Mark local file as clean */
        info->dqi_flags |= OLQF_CLEAN;
        status = ocfs2_modify_bh(sb_dqopt(sb)->files[type],
                                 oinfo->dqi_libh,
                                 olq_update_info,
                                 info);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }

out:
        ocfs2_inode_unlock(sb_dqopt(sb)->files[type], 1);
        brelse(oinfo->dqi_libh);
        brelse(oinfo->dqi_lqi_bh);
        kfree(oinfo);
        return 0;
}

static void olq_set_dquot(struct buffer_head *bh, void *private)
{
        struct ocfs2_dquot *od = private;
        struct ocfs2_local_disk_dqblk *dqblk;
        struct super_block *sb = od->dq_dquot.dq_sb;

        dqblk = (struct ocfs2_local_disk_dqblk *)(bh->b_data
                + ol_dqblk_block_offset(sb, od->dq_local_off));

        dqblk->dqb_id = cpu_to_le64(od->dq_dquot.dq_id);
        spin_lock(&dq_data_lock);
        dqblk->dqb_spacemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curspace -
                                          od->dq_origspace);
        dqblk->dqb_inodemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curinodes -
                                          od->dq_originodes);
        spin_unlock(&dq_data_lock);
        trace_olq_set_dquot(
                (unsigned long long)le64_to_cpu(dqblk->dqb_spacemod),
                (unsigned long long)le64_to_cpu(dqblk->dqb_inodemod),
                od->dq_dquot.dq_id);
}

/* Write dquot to local quota file */
int ocfs2_local_write_dquot(struct dquot *dquot)
{
        struct super_block *sb = dquot->dq_sb;
        struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
        struct buffer_head *bh;
        struct inode *lqinode = sb_dqopt(sb)->files[dquot->dq_type];
        int status;

        status = ocfs2_read_quota_phys_block(lqinode, od->dq_local_phys_blk,
                                             &bh);
        if (status) {
                mlog_errno(status);
                goto out;
        }
        status = ocfs2_modify_bh(lqinode, bh, olq_set_dquot, od);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
out:
        brelse(bh);
        return status;
}

/* Find free entry in local quota file */
static struct ocfs2_quota_chunk *ocfs2_find_free_entry(struct super_block *sb,
                                                       int type,
                                                       int *offset)
{
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
        struct ocfs2_quota_chunk *chunk;
        struct ocfs2_local_disk_chunk *dchunk;
        int found = 0, len;

        list_for_each_entry(chunk, &oinfo->dqi_chunk, qc_chunk) {
                dchunk = (struct ocfs2_local_disk_chunk *)
                                                chunk->qc_headerbh->b_data;
                if (le32_to_cpu(dchunk->dqc_free) > 0) {
                        found = 1;
                        break;
                }
        }
        if (!found)
                return NULL;

        if (chunk->qc_num < oinfo->dqi_chunks - 1) {
                len = ol_chunk_entries(sb);
        } else {
                len = (oinfo->dqi_blocks -
                       ol_quota_chunk_block(sb, chunk->qc_num) - 1)
                      * ol_quota_entries_per_block(sb);
        }

        found = ocfs2_find_next_zero_bit(dchunk->dqc_bitmap, len, 0);
        /* We failed? */
        if (found == len) {
                mlog(ML_ERROR, "Did not find empty entry in chunk %d with %u"
                     " entries free (type=%d)\n", chunk->qc_num,
                     le32_to_cpu(dchunk->dqc_free), type);
                return ERR_PTR(-EIO);
        }
        *offset = found;
        return chunk;
}

/* Add new chunk to the local quota file */
static struct ocfs2_quota_chunk *ocfs2_local_quota_add_chunk(
                                                        struct super_block *sb,
                                                        int type,
                                                        int *offset)
{
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
        struct inode *lqinode = sb_dqopt(sb)->files[type];
        struct ocfs2_quota_chunk *chunk = NULL;
        struct ocfs2_local_disk_chunk *dchunk;
        int status;
        handle_t *handle;
        struct buffer_head *bh = NULL, *dbh = NULL;
        u64 p_blkno;

        /* We are protected by dqio_sem so no locking needed */
        status = ocfs2_extend_no_holes(lqinode, NULL,
                                       lqinode->i_size + 2 * sb->s_blocksize,
                                       lqinode->i_size);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
        status = ocfs2_simple_size_update(lqinode, oinfo->dqi_lqi_bh,
                                          lqinode->i_size + 2 * sb->s_blocksize);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }

        chunk = kmem_cache_alloc(ocfs2_qf_chunk_cachep, GFP_NOFS);
        if (!chunk) {
                status = -ENOMEM;
                mlog_errno(status);
                goto out;
        }
        /* Local quota info and two new blocks we initialize */
        handle = ocfs2_start_trans(OCFS2_SB(sb),
                        OCFS2_LOCAL_QINFO_WRITE_CREDITS +
                        2 * OCFS2_QUOTA_BLOCK_UPDATE_CREDITS);
        if (IS_ERR(handle)) {

                status = PTR_ERR(handle);
                mlog_errno(status);
                goto out;
        }

        /* Initialize chunk header */
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
                                             &p_blkno, NULL, NULL);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        bh = sb_getblk(sb, p_blkno);
        if (!bh) {
                status = -ENOMEM;
                mlog_errno(status);
                goto out_trans;
        }
        dchunk = (struct ocfs2_local_disk_chunk *)bh->b_data;
        ocfs2_set_new_buffer_uptodate(INODE_CACHE(lqinode), bh);
        status = ocfs2_journal_access_dq(handle, INODE_CACHE(lqinode), bh,
                                         OCFS2_JOURNAL_ACCESS_CREATE);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        lock_buffer(bh);
        dchunk->dqc_free = cpu_to_le32(ol_quota_entries_per_block(sb));
        memset(dchunk->dqc_bitmap, 0,
               sb->s_blocksize - sizeof(struct ocfs2_local_disk_chunk) -
               OCFS2_QBLK_RESERVED_SPACE);
        unlock_buffer(bh);
        ocfs2_journal_dirty(handle, bh);

        /* Initialize new block with structures */
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks + 1,
                                             &p_blkno, NULL, NULL);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        dbh = sb_getblk(sb, p_blkno);
        if (!dbh) {
                status = -ENOMEM;
                mlog_errno(status);
                goto out_trans;
        }
        ocfs2_set_new_buffer_uptodate(INODE_CACHE(lqinode), dbh);
        status = ocfs2_journal_access_dq(handle, INODE_CACHE(lqinode), dbh,
                                         OCFS2_JOURNAL_ACCESS_CREATE);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        lock_buffer(dbh);
        memset(dbh->b_data, 0, sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE);
        unlock_buffer(dbh);
        ocfs2_journal_dirty(handle, dbh);

        /* Update local quotafile info */
        oinfo->dqi_blocks += 2;
        oinfo->dqi_chunks++;
        status = ocfs2_local_write_info(sb, type);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }

        list_add_tail(&chunk->qc_chunk, &oinfo->dqi_chunk);
        chunk->qc_num = list_entry(chunk->qc_chunk.prev,
                                   struct ocfs2_quota_chunk,
                                   qc_chunk)->qc_num + 1;
        chunk->qc_headerbh = bh;
        *offset = 0;
        return chunk;
out_trans:
        ocfs2_commit_trans(OCFS2_SB(sb), handle);
out:
        brelse(bh);
        brelse(dbh);
        kmem_cache_free(ocfs2_qf_chunk_cachep, chunk);
        return ERR_PTR(status);
}

/* Find free entry in local quota file */
static struct ocfs2_quota_chunk *ocfs2_extend_local_quota_file(
                                                       struct super_block *sb,
                                                       int type,
                                                       int *offset)
{
        struct mem_dqinfo *info = sb_dqinfo(sb, type);
        struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
        struct ocfs2_quota_chunk *chunk;
        struct inode *lqinode = sb_dqopt(sb)->files[type];
        struct ocfs2_local_disk_chunk *dchunk;
        int epb = ol_quota_entries_per_block(sb);
        unsigned int chunk_blocks;
        struct buffer_head *bh;
        u64 p_blkno;
        int status;
        handle_t *handle;

        if (list_empty(&oinfo->dqi_chunk))
                return ocfs2_local_quota_add_chunk(sb, type, offset);
        /* Is the last chunk full? */
        chunk = list_entry(oinfo->dqi_chunk.prev,
                        struct ocfs2_quota_chunk, qc_chunk);
        chunk_blocks = oinfo->dqi_blocks -
                        ol_quota_chunk_block(sb, chunk->qc_num) - 1;
        if (ol_chunk_blocks(sb) == chunk_blocks)
                return ocfs2_local_quota_add_chunk(sb, type, offset);

        /* We are protected by dqio_sem so no locking needed */
        status = ocfs2_extend_no_holes(lqinode, NULL,
                                       lqinode->i_size + sb->s_blocksize,
                                       lqinode->i_size);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
        status = ocfs2_simple_size_update(lqinode, oinfo->dqi_lqi_bh,
                                          lqinode->i_size + sb->s_blocksize);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }

        /* Get buffer from the just added block */
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
                                             &p_blkno, NULL, NULL);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
        bh = sb_getblk(sb, p_blkno);
        if (!bh) {
                status = -ENOMEM;
                mlog_errno(status);
                goto out;
        }
        ocfs2_set_new_buffer_uptodate(INODE_CACHE(lqinode), bh);

        /* Local quota info, chunk header and the new block we initialize */
        handle = ocfs2_start_trans(OCFS2_SB(sb),
                        OCFS2_LOCAL_QINFO_WRITE_CREDITS +
                        2 * OCFS2_QUOTA_BLOCK_UPDATE_CREDITS);
        if (IS_ERR(handle)) {
                status = PTR_ERR(handle);
                mlog_errno(status);
                goto out;
        }
        /* Zero created block */
        status = ocfs2_journal_access_dq(handle, INODE_CACHE(lqinode), bh,
                                 OCFS2_JOURNAL_ACCESS_CREATE);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }
        lock_buffer(bh);
        memset(bh->b_data, 0, sb->s_blocksize);
        unlock_buffer(bh);
        ocfs2_journal_dirty(handle, bh);

        /* Update chunk header */
        status = ocfs2_journal_access_dq(handle, INODE_CACHE(lqinode),
                                         chunk->qc_headerbh,
                                 OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }

        dchunk = (struct ocfs2_local_disk_chunk *)chunk->qc_headerbh->b_data;
        lock_buffer(chunk->qc_headerbh);
        le32_add_cpu(&dchunk->dqc_free, ol_quota_entries_per_block(sb));
        unlock_buffer(chunk->qc_headerbh);
        ocfs2_journal_dirty(handle, chunk->qc_headerbh);

        /* Update file header */
        oinfo->dqi_blocks++;
        status = ocfs2_local_write_info(sb, type);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
        }

        status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
        *offset = chunk_blocks * epb;
        return chunk;
out_trans:
        ocfs2_commit_trans(OCFS2_SB(sb), handle);
out:
        return ERR_PTR(status);
}

static void olq_alloc_dquot(struct buffer_head *bh, void *private)
{
        int *offset = private;
        struct ocfs2_local_disk_chunk *dchunk;

        dchunk = (struct ocfs2_local_disk_chunk *)bh->b_data;
        ocfs2_set_bit(*offset, dchunk->dqc_bitmap);
        le32_add_cpu(&dchunk->dqc_free, -1);
}

/* Create dquot in the local file for given id */
int ocfs2_create_local_dquot(struct dquot *dquot)
{
        struct super_block *sb = dquot->dq_sb;
        int type = dquot->dq_type;
        struct inode *lqinode = sb_dqopt(sb)->files[type];
        struct ocfs2_quota_chunk *chunk;
        struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
        int offset;
        int status;
        u64 pcount;

        down_write(&OCFS2_I(lqinode)->ip_alloc_sem);
        chunk = ocfs2_find_free_entry(sb, type, &offset);
        if (!chunk) {
                chunk = ocfs2_extend_local_quota_file(sb, type, &offset);
                if (IS_ERR(chunk)) {
                        status = PTR_ERR(chunk);
                        goto out;
                }
        } else if (IS_ERR(chunk)) {
                status = PTR_ERR(chunk);
                goto out;
        }
        od->dq_local_off = ol_dqblk_off(sb, chunk->qc_num, offset);
        od->dq_chunk = chunk;
        status = ocfs2_extent_map_get_blocks(lqinode,
                                     ol_dqblk_block(sb, chunk->qc_num, offset),
                                     &od->dq_local_phys_blk,
                                     &pcount,
                                     NULL);

        /* Initialize dquot structure on disk */
        status = ocfs2_local_write_dquot(dquot);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }

        /* Mark structure as allocated */
        status = ocfs2_modify_bh(lqinode, chunk->qc_headerbh, olq_alloc_dquot,
                                 &offset);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
out:
        up_write(&OCFS2_I(lqinode)->ip_alloc_sem);
        return status;
}

/*
 * Release dquot structure from local quota file. ocfs2_release_dquot() has
 * already started a transaction and written all changes to global quota file
 */
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot)
{
        int status;
        int type = dquot->dq_type;
        struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
        struct super_block *sb = dquot->dq_sb;
        struct ocfs2_local_disk_chunk *dchunk;
        int offset;

        status = ocfs2_journal_access_dq(handle,
                        INODE_CACHE(sb_dqopt(sb)->files[type]),
                        od->dq_chunk->qc_headerbh, OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                goto out;
        }
        offset = ol_dqblk_chunk_off(sb, od->dq_chunk->qc_num,
                                             od->dq_local_off);
        dchunk = (struct ocfs2_local_disk_chunk *)
                        (od->dq_chunk->qc_headerbh->b_data);
        /* Mark structure as freed */
        lock_buffer(od->dq_chunk->qc_headerbh);
        ocfs2_clear_bit(offset, dchunk->dqc_bitmap);
        le32_add_cpu(&dchunk->dqc_free, 1);
        unlock_buffer(od->dq_chunk->qc_headerbh);
        ocfs2_journal_dirty(handle, od->dq_chunk->qc_headerbh);

out:
        /* Clear the read bit so that next time someone uses this
         * dquot he reads fresh info from disk and allocates local
         * dquot structure */
        clear_bit(DQ_READ_B, &dquot->dq_flags);
        return status;
}

static const struct quota_format_ops ocfs2_format_ops = {
        .check_quota_file       = ocfs2_local_check_quota_file,
        .read_file_info         = ocfs2_local_read_info,
        .write_file_info        = ocfs2_global_write_info,
        .free_file_info         = ocfs2_local_free_info,
};

struct quota_format_type ocfs2_quota_format = {
        .qf_fmt_id = QFMT_OCFS2,
        .qf_ops = &ocfs2_format_ops,
        .qf_owner = THIS_MODULE
};