quota_local.c

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/*
 *  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;

    printk(KERN_NOTICE "ocfs2: Beginning quota recovery on device (%s) for "
           "slot %u\n", osb->dev_str, 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,
                      make_kqid(&init_user_ns, type,
                        le64_to_cpu(dqblk->dqb_id)));
            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_unaligned(bit, dchunk->dqc_bitmap));
            ocfs2_clear_bit_unaligned(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;

    printk(KERN_NOTICE "ocfs2: Finishing quota recovery on device (%s) for "
           "slot %u\n", osb->dev_str, 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) {
            printk(KERN_NOTICE "ocfs2: Skipping quota recovery on "
                   "device (%s) for slot %d because quota file is "
                   "locked.\n", osb->dev_str, 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(from_kqid(&init_user_ns,
                          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),
        from_kqid(&init_user_ns, 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_id.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_unaligned(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_unaligned(*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_id.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_id.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_unaligned(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
};