/*
   *  Implementation of operations over local quota file
   */
  
  #include <linux/fs.h>
  #include <linux/quota.h>
  #include <linux/quotaops.h>
  #include <linux/module.h>
  
  #define MLOG_MASK_PREFIX ML_QUOTA
  #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"
  
  /* 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), 1);
  	if (IS_ERR(handle)) {
  		status = PTR_ERR(handle);
  		mlog_errno(status);
  		return status;
  	}

  	status = ocfs2_journal_access_dq(handle, 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);
  	status = ocfs2_journal_dirty(handle, bh);
  	if (status < 0) {
  		mlog_errno(status);
  		ocfs2_commit_trans(OCFS2_SB(sb), handle);
  		return status;
  	}
  	status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
  	if (status < 0) {
  		mlog_errno(status);
  		return status;
  	}
  	return 0;
  }
  
  /* 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)
  ",
  			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
  ", 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
  ", 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)
  ", 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)
  ", 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
  ",
  			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
  ",
  			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
  ", 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)
  ", 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;
  
  	mlog_entry("ino=%lu type=%u", (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_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.
  ",
  				     (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, 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);
  			status = ocfs2_journal_dirty(handle, qbh);
  			if (status < 0)
  				mlog_errno(status);
  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]));
  	mlog_exit(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
  ", slot_num);
  	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
  	for (type = 0; type < MAXQUOTAS; type++) {
  		if (list_empty(&(rec->r_list[type])))
  			continue;
  		mlog(0, "Recovering quota in slot %d
  ", 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.
  ", 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)
  ", 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, 1);
  		if (IS_ERR(handle)) {
  			status = PTR_ERR(handle);
  			mlog_errno(status);
  			goto out_bh;
  		}

  		status = ocfs2_journal_access_dq(handle, 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);
  		status = ocfs2_journal_dirty(handle, bh);
  		if (status < 0)
  			mlog_errno(status);
  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_ibh = 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)
  ", 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_ibh = 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_ibh;
  	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;

  	/* At this point we know there are no more dquots and thus
  	 * even if there's some sync in the pdflush queue, it won't
  	 * find any dquots and return without doing anything */
  	cancel_delayed_work_sync(&oinfo->dqi_sync_work);

  	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)
  ", 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_ibh,
  				 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_ibh);
  	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);
  	mlog(0, "Writing local dquot %u space %lld inodes %lld
  ",

  	     od->dq_dquot.dq_id, (long long)le64_to_cpu(dqblk->dqb_spacemod),
  	     (long long)le64_to_cpu(dqblk->dqb_inodemod));

  }
  
  /* Write dquot to local quota file */
  static 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 = NULL;

  	int status;

  	status = ocfs2_read_quota_block(sb_dqopt(sb)->files[dquot->dq_type],

  				    ol_dqblk_file_block(sb, od->dq_local_off),

  				    &bh);
  	if (status) {

  		mlog_errno(status);
  		goto out;
  	}
  	status = ocfs2_modify_bh(sb_dqopt(sb)->files[dquot->dq_type], 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)
  ", 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;
  	u64 p_blkno;
  
  	/* We are protected by dqio_sem so no locking needed */
  	status = ocfs2_extend_no_holes(lqinode,
  				       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;
  	}
  
  	down_read(&OCFS2_I(lqinode)->ip_alloc_sem);
  	status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
  					     &p_blkno, NULL, NULL);
  	up_read(&OCFS2_I(lqinode)->ip_alloc_sem);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out;
  	}
  	bh = sb_getblk(sb, p_blkno);
  	if (!bh) {
  		status = -ENOMEM;
  		mlog_errno(status);
  		goto out;
  	}
  	dchunk = (struct ocfs2_local_disk_chunk *)bh->b_data;
  
  	handle = ocfs2_start_trans(OCFS2_SB(sb), 2);
  	if (IS_ERR(handle)) {
  		status = PTR_ERR(handle);
  		mlog_errno(status);
  		goto out;
  	}

  	status = ocfs2_journal_access_dq(handle, lqinode, bh,
  					 OCFS2_JOURNAL_ACCESS_WRITE);

  	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);
  	set_buffer_uptodate(bh);
  	unlock_buffer(bh);
  	status = ocfs2_journal_dirty(handle, bh);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out_trans;
  	}
  
  	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);
  	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;
  	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,
  				       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;
  	}
  	handle = ocfs2_start_trans(OCFS2_SB(sb), 2);
  	if (IS_ERR(handle)) {
  		status = PTR_ERR(handle);
  		mlog_errno(status);
  		goto out;
  	}

  	status = ocfs2_journal_access_dq(handle, 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);
  	status = ocfs2_journal_dirty(handle, chunk->qc_headerbh);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out_trans;
  	}
  	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 */
  static 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;
  
  	chunk = ocfs2_find_free_entry(sb, type, &offset);
  	if (!chunk) {
  		chunk = ocfs2_extend_local_quota_file(sb, type, &offset);
  		if (IS_ERR(chunk))
  			return PTR_ERR(chunk);
  	} else if (IS_ERR(chunk)) {
  		return PTR_ERR(chunk);
  	}
  	od->dq_local_off = ol_dqblk_off(sb, chunk->qc_num, offset);
  	od->dq_chunk = chunk;
  
  	/* 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:
  	return status;
  }
  
  /* Create entry in local file for dquot, load data from the global file */
  static int ocfs2_local_read_dquot(struct dquot *dquot)
  {
  	int status;
  
  	mlog_entry("id=%u, type=%d
  ", dquot->dq_id, dquot->dq_type);
  
  	status = ocfs2_global_read_dquot(dquot);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out_err;
  	}
  
  	/* Now create entry in the local quota file */
  	status = ocfs2_create_local_dquot(dquot);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out_err;
  	}
  	mlog_exit(0);
  	return 0;
  out_err:
  	mlog_exit(status);
  	return status;
  }
  
  /* Release dquot structure from local quota file. ocfs2_release_dquot() has
   * already started a transaction and obtained exclusive lock for global
   * quota file. */
  static int ocfs2_local_release_dquot(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;
  	handle_t *handle = journal_current_handle();
  
  	BUG_ON(!handle);
  	/* First write all local changes to global file */
  	status = ocfs2_global_release_dquot(dquot);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out;
  	}

  	status = ocfs2_journal_access_dq(handle, 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);
  	status = ocfs2_journal_dirty(handle, od->dq_chunk->qc_headerbh);
  	if (status < 0) {
  		mlog_errno(status);
  		goto out;
  	}
  	status = 0;
  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 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,
  	.read_dqblk		= ocfs2_local_read_dquot,
  	.commit_dqblk		= ocfs2_local_write_dquot,
  	.release_dqblk		= ocfs2_local_release_dquot,
  };
  
  struct quota_format_type ocfs2_quota_format = {
  	.qf_fmt_id = QFMT_OCFS2,
  	.qf_ops = &ocfs2_format_ops,
  	.qf_owner = THIS_MODULE
  };