/* -*- mode: c; c-basic-offset: 8; -*-
   * vim: noexpandtab sw=8 ts=8 sts=0:
   *
   * journal.h
   *
   * Defines journalling api and structures.
   *
   * Copyright (C) 2003, 2005 Oracle.  All rights reserved.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public
   * License as published by the Free Software Foundation; either
   * version 2 of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public
   * License along with this program; if not, write to the
   * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   * Boston, MA 021110-1307, USA.
   */
  
  #ifndef OCFS2_JOURNAL_H
  #define OCFS2_JOURNAL_H
  
  #include <linux/fs.h>
  #include <linux/jbd2.h>
  
  enum ocfs2_journal_state {
  	OCFS2_JOURNAL_FREE = 0,
  	OCFS2_JOURNAL_LOADED,
  	OCFS2_JOURNAL_IN_SHUTDOWN,
  };
  
  struct ocfs2_super;
  struct ocfs2_dinode;
  
  /*
   * The recovery_list is a simple linked list of node numbers to recover.
   * It is protected by the recovery_lock.
   */
  
  struct ocfs2_recovery_map {
  	unsigned int rm_used;
  	unsigned int *rm_entries;
  };
  
  
  struct ocfs2_journal {
  	enum ocfs2_journal_state   j_state;    /* Journals current state   */
  
  	journal_t                 *j_journal; /* The kernels journal type */
  	struct inode              *j_inode;   /* Kernel inode pointing to
  					       * this journal             */
  	struct ocfs2_super        *j_osb;     /* pointer to the super
  					       * block for the node
  					       * we're currently
  					       * running on -- not
  					       * necessarily the super
  					       * block from the node
  					       * which we usually run
  					       * from (recovery,
  					       * etc)                     */
  	struct buffer_head        *j_bh;      /* Journal disk inode block */
  	atomic_t                  j_num_trans; /* Number of transactions
  					        * currently in the system. */
  	spinlock_t                j_lock;
  	unsigned long             j_trans_id;
  	struct rw_semaphore       j_trans_barrier;
  	wait_queue_head_t         j_checkpointed;
  
  	/* both fields protected by j_lock*/
  	struct list_head          j_la_cleanups;
  	struct work_struct        j_recovery_work;
  };
  
  extern spinlock_t trans_inc_lock;
  
  /* wrap j_trans_id so we never have it equal to zero. */
  static inline unsigned long ocfs2_inc_trans_id(struct ocfs2_journal *j)
  {
  	unsigned long old_id;
  	spin_lock(&trans_inc_lock);
  	old_id = j->j_trans_id++;
  	if (unlikely(!j->j_trans_id))
  		j->j_trans_id = 1;
  	spin_unlock(&trans_inc_lock);
  	return old_id;
  }
  
  static inline void ocfs2_set_ci_lock_trans(struct ocfs2_journal *journal,
  					   struct ocfs2_caching_info *ci)
  {
  	spin_lock(&trans_inc_lock);
  	ci->ci_last_trans = journal->j_trans_id;
  	spin_unlock(&trans_inc_lock);
  }
  
  /* Used to figure out whether it's safe to drop a metadata lock on an
   * cached object. Returns true if all the object's changes have been
   * checkpointed to disk. You should be holding the spinlock on the
   * metadata lock while calling this to be sure that nobody can take
   * the lock and put it on another transaction. */
  static inline int ocfs2_ci_fully_checkpointed(struct ocfs2_caching_info *ci)
  {
  	int ret;
  	struct ocfs2_journal *journal =
  		OCFS2_SB(ocfs2_metadata_cache_get_super(ci))->journal;
  
  	spin_lock(&trans_inc_lock);
  	ret = time_after(journal->j_trans_id, ci->ci_last_trans);
  	spin_unlock(&trans_inc_lock);
  	return ret;
  }
  
  /* convenience function to check if an object backed by struct
   * ocfs2_caching_info  is still new (has never hit disk) Will do you a
   * favor and set created_trans = 0 when you've
   * been checkpointed.  returns '1' if the ci is still new. */
  static inline int ocfs2_ci_is_new(struct ocfs2_caching_info *ci)
  {
  	int ret;
  	struct ocfs2_journal *journal =
  		OCFS2_SB(ocfs2_metadata_cache_get_super(ci))->journal;
  
  	spin_lock(&trans_inc_lock);
  	ret = !(time_after(journal->j_trans_id, ci->ci_created_trans));
  	if (!ret)
  		ci->ci_created_trans = 0;
  	spin_unlock(&trans_inc_lock);
  	return ret;
  }
  
  /* Wrapper for inodes so we can check system files */
  static inline int ocfs2_inode_is_new(struct inode *inode)
  {
  	/* System files are never "new" as they're written out by
  	 * mkfs. This helps us early during mount, before we have the
  	 * journal open and j_trans_id could be junk. */
  	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
  		return 0;
  
  	return ocfs2_ci_is_new(INODE_CACHE(inode));
  }
  
  static inline void ocfs2_ci_set_new(struct ocfs2_super *osb,
  				    struct ocfs2_caching_info *ci)
  {
  	spin_lock(&trans_inc_lock);
  	ci->ci_created_trans = osb->journal->j_trans_id;
  	spin_unlock(&trans_inc_lock);
  }
  
  /* Exported only for the journal struct init code in super.c. Do not call. */
  void ocfs2_orphan_scan_init(struct ocfs2_super *osb);
  void ocfs2_orphan_scan_start(struct ocfs2_super *osb);
  void ocfs2_orphan_scan_stop(struct ocfs2_super *osb);
  void ocfs2_orphan_scan_exit(struct ocfs2_super *osb);
  
  void ocfs2_complete_recovery(struct work_struct *work);
  void ocfs2_wait_for_recovery(struct ocfs2_super *osb);
  
  int ocfs2_recovery_init(struct ocfs2_super *osb);
  void ocfs2_recovery_exit(struct ocfs2_super *osb);
  
  int ocfs2_compute_replay_slots(struct ocfs2_super *osb);
  /*
   *  Journal Control:
   *  Initialize, Load, Shutdown, Wipe a journal.
   *
   *  ocfs2_journal_init     - Initialize journal structures in the OSB.
   *  ocfs2_journal_load     - Load the given journal off disk. Replay it if
   *                          there's transactions still in there.
   *  ocfs2_journal_shutdown - Shutdown a journal, this will flush all
   *                          uncommitted, uncheckpointed transactions.
   *  ocfs2_journal_wipe     - Wipe transactions from a journal. Optionally
   *                          zero out each block.
   *  ocfs2_recovery_thread  - Perform recovery on a node. osb is our own osb.
   *  ocfs2_mark_dead_nodes - Start recovery on nodes we won't get a heartbeat
   *                          event on.
   *  ocfs2_start_checkpoint - Kick the commit thread to do a checkpoint.
   */
  void   ocfs2_set_journal_params(struct ocfs2_super *osb);
  int    ocfs2_journal_init(struct ocfs2_journal *journal,
  			  int *dirty);
  void   ocfs2_journal_shutdown(struct ocfs2_super *osb);
  int    ocfs2_journal_wipe(struct ocfs2_journal *journal,
  			  int full);
  int    ocfs2_journal_load(struct ocfs2_journal *journal, int local,
  			  int replayed);
  int    ocfs2_check_journals_nolocks(struct ocfs2_super *osb);
  void   ocfs2_recovery_thread(struct ocfs2_super *osb,
  			     int node_num);
  int    ocfs2_mark_dead_nodes(struct ocfs2_super *osb);
  void   ocfs2_complete_mount_recovery(struct ocfs2_super *osb);
  void ocfs2_complete_quota_recovery(struct ocfs2_super *osb);
  
  static inline void ocfs2_start_checkpoint(struct ocfs2_super *osb)
  {
  	wake_up(&osb->checkpoint_event);
  }
  
  static inline void ocfs2_checkpoint_inode(struct inode *inode)
  {
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  
  	if (ocfs2_mount_local(osb))
  		return;
  
  	if (!ocfs2_ci_fully_checkpointed(INODE_CACHE(inode))) {
  		/* WARNING: This only kicks off a single
  		 * checkpoint. If someone races you and adds more
  		 * metadata to the journal, you won't know, and will
  		 * wind up waiting *a lot* longer than necessary. Right
  		 * now we only use this in clear_inode so that's
  		 * OK. */
  		ocfs2_start_checkpoint(osb);
  
  		wait_event(osb->journal->j_checkpointed,
  			   ocfs2_ci_fully_checkpointed(INODE_CACHE(inode)));
  	}
  }
  
  /*
   *  Transaction Handling:
   *  Manage the lifetime of a transaction handle.
   *
   *  ocfs2_start_trans      - Begin a transaction. Give it an upper estimate of
   *                          the number of blocks that will be changed during
   *                          this handle.
   *  ocfs2_commit_trans - Complete a handle. It might return -EIO if
   *                       the journal was aborted. The majority of paths don't
   *                       check the return value as an error there comes too
   *                       late to do anything (and will be picked up in a
   *                       later transaction).
   *  ocfs2_extend_trans     - Extend a handle by nblocks credits. This may
   *                          commit the handle to disk in the process, but will
   *                          not release any locks taken during the transaction.
   *  ocfs2_journal_access* - Notify the handle that we want to journal this
   *                          buffer. Will have to call ocfs2_journal_dirty once
   *                          we've actually dirtied it. Type is one of . or .
   *                          Always call the specific flavor of
   *                          ocfs2_journal_access_*() unless you intend to
   *                          manage the checksum by hand.
   *  ocfs2_journal_dirty    - Mark a journalled buffer as having dirty data.
   *  ocfs2_jbd2_file_inode  - Mark an inode so that its data goes out before
   *                           the current handle commits.
   */
  
  /* You must always start_trans with a number of buffs > 0, but it's
   * perfectly legal to go through an entire transaction without having
   * dirtied any buffers. */
  handle_t		    *ocfs2_start_trans(struct ocfs2_super *osb,
  					       int max_buffs);
  int			     ocfs2_commit_trans(struct ocfs2_super *osb,
  						handle_t *handle);
  int			     ocfs2_extend_trans(handle_t *handle, int nblocks);
  int			     ocfs2_allocate_extend_trans(handle_t *handle,
  						int thresh);
  
  /*
   * Define an arbitrary limit for the amount of data we will anticipate
   * writing to any given transaction.  For unbounded transactions such as
   * fallocate(2) we can write more than this, but we always
   * start off at the maximum transaction size and grow the transaction
   * optimistically as we go.
   */
  #define OCFS2_MAX_TRANS_DATA	64U
  
  /*
   * Create access is for when we get a newly created buffer and we're
   * not gonna read it off disk, but rather fill it ourselves.  Right
   * now, we don't do anything special with this (it turns into a write
   * request), but this is a good placeholder in case we do...
   *
   * Write access is for when we read a block off disk and are going to
   * modify it. This way the journalling layer knows it may need to make
   * a copy of that block (if it's part of another, uncommitted
   * transaction) before we do so.
   */
  #define OCFS2_JOURNAL_ACCESS_CREATE 0
  #define OCFS2_JOURNAL_ACCESS_WRITE  1
  #define OCFS2_JOURNAL_ACCESS_UNDO   2
  
  
  /* ocfs2_inode */
  int ocfs2_journal_access_di(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_extent_block */
  int ocfs2_journal_access_eb(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_refcount_block */
  int ocfs2_journal_access_rb(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_group_desc */
  int ocfs2_journal_access_gd(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_xattr_block */
  int ocfs2_journal_access_xb(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* quota blocks */
  int ocfs2_journal_access_dq(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* dirblock */
  int ocfs2_journal_access_db(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_dx_root_block */
  int ocfs2_journal_access_dr(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* ocfs2_dx_leaf */
  int ocfs2_journal_access_dl(handle_t *handle, struct ocfs2_caching_info *ci,
  			    struct buffer_head *bh, int type);
  /* Anything that has no ecc */
  int ocfs2_journal_access(handle_t *handle, struct ocfs2_caching_info *ci,
  			 struct buffer_head *bh, int type);
  
  /*
   * A word about the journal_access/journal_dirty "dance". It is
   * entirely legal to journal_access a buffer more than once (as long
   * as the access type is the same -- I'm not sure what will happen if
   * access type is different but this should never happen anyway) It is
   * also legal to journal_dirty a buffer more than once. In fact, you
   * can even journal_access a buffer after you've done a
   * journal_access/journal_dirty pair. The only thing you cannot do
   * however, is journal_dirty a buffer which you haven't yet passed to
   * journal_access at least once.
   *
   * That said, 99% of the time this doesn't matter and this is what the
   * path looks like:
   *
   *	<read a bh>
   *	ocfs2_journal_access(handle, bh,	OCFS2_JOURNAL_ACCESS_WRITE);
   *	<modify the bh>
   * 	ocfs2_journal_dirty(handle, bh);
   */
  void ocfs2_journal_dirty(handle_t *handle, struct buffer_head *bh);
  
  /*
   *  Credit Macros:
   *  Convenience macros to calculate number of credits needed.
   *
   *  For convenience sake, I have a set of macros here which calculate
   *  the *maximum* number of sectors which will be changed for various
   *  metadata updates.
   */
  
  /* simple file updates like chmod, etc. */
  #define OCFS2_INODE_UPDATE_CREDITS 1
  
  /* extended attribute block update */
  #define OCFS2_XATTR_BLOCK_UPDATE_CREDITS 1
  
  /* Update of a single quota block */
  #define OCFS2_QUOTA_BLOCK_UPDATE_CREDITS 1
  
  /* global quotafile inode update, data block */
  #define OCFS2_QINFO_WRITE_CREDITS (OCFS2_INODE_UPDATE_CREDITS + \
  				   OCFS2_QUOTA_BLOCK_UPDATE_CREDITS)
  
  #define OCFS2_LOCAL_QINFO_WRITE_CREDITS OCFS2_QUOTA_BLOCK_UPDATE_CREDITS
  /*
   * The two writes below can accidentally see global info dirty due
   * to set_info() quotactl so make them prepared for the writes.
   */
  /* quota data block, global info */
  /* Write to local quota file */
  #define OCFS2_QWRITE_CREDITS (OCFS2_QINFO_WRITE_CREDITS + \
  			      OCFS2_QUOTA_BLOCK_UPDATE_CREDITS)
  
  /* global quota data block, local quota data block, global quota inode,
   * global quota info */
  #define OCFS2_QSYNC_CREDITS (OCFS2_QINFO_WRITE_CREDITS + \
  			     2 * OCFS2_QUOTA_BLOCK_UPDATE_CREDITS)
  
  static inline int ocfs2_quota_trans_credits(struct super_block *sb)
  {
  	int credits = 0;
  
  	if (OCFS2_HAS_RO_COMPAT_FEATURE(sb, OCFS2_FEATURE_RO_COMPAT_USRQUOTA))
  		credits += OCFS2_QWRITE_CREDITS;
  	if (OCFS2_HAS_RO_COMPAT_FEATURE(sb, OCFS2_FEATURE_RO_COMPAT_GRPQUOTA))
  		credits += OCFS2_QWRITE_CREDITS;
  	return credits;
  }
  
  /* group extend. inode update and last group update. */
  #define OCFS2_GROUP_EXTEND_CREDITS	(OCFS2_INODE_UPDATE_CREDITS + 1)
  
  /* group add. inode update and the new group update. */
  #define OCFS2_GROUP_ADD_CREDITS	(OCFS2_INODE_UPDATE_CREDITS + 1)
  
  /* get one bit out of a suballocator: dinode + group descriptor +
   * prev. group desc. if we relink. */
  #define OCFS2_SUBALLOC_ALLOC (3)
  
  static inline int ocfs2_inline_to_extents_credits(struct super_block *sb)
  {
  	return OCFS2_SUBALLOC_ALLOC + OCFS2_INODE_UPDATE_CREDITS +
  	       ocfs2_quota_trans_credits(sb);
  }
  
  /* dinode + group descriptor update. We don't relink on free yet. */
  #define OCFS2_SUBALLOC_FREE  (2)
  
  #define OCFS2_TRUNCATE_LOG_UPDATE OCFS2_INODE_UPDATE_CREDITS
  #define OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC (OCFS2_SUBALLOC_FREE 		      \
  					 + OCFS2_TRUNCATE_LOG_UPDATE)
  
  static inline int ocfs2_remove_extent_credits(struct super_block *sb)
  {
  	return OCFS2_TRUNCATE_LOG_UPDATE + OCFS2_INODE_UPDATE_CREDITS +
  	       ocfs2_quota_trans_credits(sb);
  }
  
  /* data block for new dir/symlink, allocation of directory block, dx_root
   * update for free list */
  #define OCFS2_DIR_LINK_ADDITIONAL_CREDITS (1 + OCFS2_SUBALLOC_ALLOC + 1)
  
  static inline int ocfs2_add_dir_index_credits(struct super_block *sb)
  {
  	/* 1 block for index, 2 allocs (data, metadata), 1 clusters
  	 * worth of blocks for initial extent. */
  	return 1 + 2 * OCFS2_SUBALLOC_ALLOC +
  		ocfs2_clusters_to_blocks(sb, 1);
  }
  
  /* parent fe, parent block, new file entry, index leaf, inode alloc fe, inode
   * alloc group descriptor + mkdir/symlink blocks + dir blocks + xattr
   * blocks + quota update */
  static inline int ocfs2_mknod_credits(struct super_block *sb, int is_dir,
  				      int xattr_credits)
  {
  	int dir_credits = OCFS2_DIR_LINK_ADDITIONAL_CREDITS;
  
  	if (is_dir)
  		dir_credits += ocfs2_add_dir_index_credits(sb);
  
  	return 4 + OCFS2_SUBALLOC_ALLOC + dir_credits + xattr_credits +
  	       ocfs2_quota_trans_credits(sb);
  }
  
  /* local alloc metadata change + main bitmap updates */
  #define OCFS2_WINDOW_MOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS                 \
  				  + OCFS2_SUBALLOC_ALLOC + OCFS2_SUBALLOC_FREE)
  
  /* used when we don't need an allocation change for a dir extend. One
   * for the dinode, one for the new block. */
  #define OCFS2_SIMPLE_DIR_EXTEND_CREDITS (2)
  
  /* file update (nlink, etc) + directory mtime/ctime + dir entry block + quota
   * update on dir + index leaf + dx root update for free list +
   * previous dirblock update in the free list */
  static inline int ocfs2_link_credits(struct super_block *sb)
  {
  	return 2*OCFS2_INODE_UPDATE_CREDITS + 4 +
  	       ocfs2_quota_trans_credits(sb);
  }
  
  /* inode + dir inode (if we unlink a dir), + dir entry block + orphan
   * dir inode link + dir inode index leaf + dir index root */
  static inline int ocfs2_unlink_credits(struct super_block *sb)
  {
  	/* The quota update from ocfs2_link_credits is unused here... */
  	return 2 * OCFS2_INODE_UPDATE_CREDITS + 3 + ocfs2_link_credits(sb);
  }
  
  /* dinode + orphan dir dinode + inode alloc dinode + orphan dir entry +
   * inode alloc group descriptor + orphan dir index root +
   * orphan dir index leaf */
  #define OCFS2_DELETE_INODE_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 4)
  
  /* dinode update, old dir dinode update, new dir dinode update, old
   * dir dir entry, new dir dir entry, dir entry update for renaming
   * directory + target unlink + 3 x dir index leaves */
  static inline int ocfs2_rename_credits(struct super_block *sb)
  {
  	return 3 * OCFS2_INODE_UPDATE_CREDITS + 6 + ocfs2_unlink_credits(sb);
  }
  
  /* global bitmap dinode, group desc., relinked group,
   * suballocator dinode, group desc., relinked group,
   * dinode, xattr block */
  #define OCFS2_XATTR_BLOCK_CREATE_CREDITS (OCFS2_SUBALLOC_ALLOC * 2 + \
  					  + OCFS2_INODE_UPDATE_CREDITS \
  					  + OCFS2_XATTR_BLOCK_UPDATE_CREDITS)
  
  /* inode update, removal of dx root block from allocator */
  #define OCFS2_DX_ROOT_REMOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS +	\
  				      OCFS2_SUBALLOC_FREE)
  
  static inline int ocfs2_calc_dxi_expand_credits(struct super_block *sb)
  {
  	int credits = 1 + OCFS2_SUBALLOC_ALLOC;
  
  	credits += ocfs2_clusters_to_blocks(sb, 1);
  	credits += ocfs2_quota_trans_credits(sb);
  
  	return credits;
  }
  
  /* inode update, new refcount block and its allocation credits. */
  #define OCFS2_REFCOUNT_TREE_CREATE_CREDITS (OCFS2_INODE_UPDATE_CREDITS + 1 \
  					    + OCFS2_SUBALLOC_ALLOC)
  
  /* inode and the refcount block update. */
  #define OCFS2_REFCOUNT_TREE_SET_CREDITS (OCFS2_INODE_UPDATE_CREDITS + 1)
  
  /*
   * inode and the refcount block update.
   * It doesn't include the credits for sub alloc change.
   * So if we need to free the bit, OCFS2_SUBALLOC_FREE needs to be added.
   */
  #define OCFS2_REFCOUNT_TREE_REMOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS + 1)
  
  /* 2 metadata alloc, 2 new blocks and root refcount block */
  #define OCFS2_EXPAND_REFCOUNT_TREE_CREDITS (OCFS2_SUBALLOC_ALLOC * 2 + 3)
  
  /*
   * Please note that the caller must make sure that root_el is the root
   * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
   * the result may be wrong.
   */
  static inline int ocfs2_calc_extend_credits(struct super_block *sb,
  					    struct ocfs2_extent_list *root_el)
  {
  	int bitmap_blocks, sysfile_bitmap_blocks, extent_blocks;
  
  	/* bitmap dinode, group desc. + relinked group. */
  	bitmap_blocks = OCFS2_SUBALLOC_ALLOC;
  
  	/* we might need to shift tree depth so lets assume an
  	 * absolute worst case of complete fragmentation.  Even with
  	 * that, we only need one update for the dinode, and then
  	 * however many metadata chunks needed * a remaining suballoc
  	 * alloc. */
  	sysfile_bitmap_blocks = 1 +
  		(OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(root_el);
  
  	/* this does not include *new* metadata blocks, which are
  	 * accounted for in sysfile_bitmap_blocks. root_el +
  	 * prev. last_eb_blk + blocks along edge of tree.
  	 * calc_symlink_credits passes because we just need 1
  	 * credit for the dinode there. */
  	extent_blocks = 1 + 1 + le16_to_cpu(root_el->l_tree_depth);
  
  	return bitmap_blocks + sysfile_bitmap_blocks + extent_blocks +
  	       ocfs2_quota_trans_credits(sb);
  }
  
  static inline int ocfs2_calc_symlink_credits(struct super_block *sb)
  {
  	int blocks = ocfs2_mknod_credits(sb, 0, 0);
  
  	/* links can be longer than one block so we may update many
  	 * within our single allocated extent. */
  	blocks += ocfs2_clusters_to_blocks(sb, 1);
  
  	return blocks + ocfs2_quota_trans_credits(sb);
  }
  
  static inline int ocfs2_calc_group_alloc_credits(struct super_block *sb,
  						 unsigned int cpg)
  {
  	int blocks;
  	int bitmap_blocks = OCFS2_SUBALLOC_ALLOC + 1;
  	/* parent inode update + new block group header + bitmap inode update
  	   + bitmap blocks affected */
  	blocks = 1 + 1 + 1 + bitmap_blocks;
  	return blocks;
  }
  
  /*
   * Allocating a discontiguous block group requires the credits from
   * ocfs2_calc_group_alloc_credits() as well as enough credits to fill
   * the group descriptor's extent list.  The caller already has started
   * the transaction with ocfs2_calc_group_alloc_credits().  They extend
   * it with these credits.
   */
  static inline int ocfs2_calc_bg_discontig_credits(struct super_block *sb)
  {
  	return ocfs2_extent_recs_per_gd(sb);
  }
  
  static inline int ocfs2_calc_tree_trunc_credits(struct super_block *sb,
  						unsigned int clusters_to_del,
  						struct ocfs2_dinode *fe,
  						struct ocfs2_extent_list *last_el)
  {
   	/* for dinode + all headers in this pass + update to next leaf */
  	u16 next_free = le16_to_cpu(last_el->l_next_free_rec);
  	u16 tree_depth = le16_to_cpu(fe->id2.i_list.l_tree_depth);
  	int credits = 1 + tree_depth + 1;
  	int i;
  
  	i = next_free - 1;
  	BUG_ON(i < 0);
  
  	/* We may be deleting metadata blocks, so metadata alloc dinode +
  	   one desc. block for each possible delete. */
  	if (tree_depth && next_free == 1 &&
  	    ocfs2_rec_clusters(last_el, &last_el->l_recs[i]) == clusters_to_del)
  		credits += 1 + tree_depth;
  
  	/* update to the truncate log. */
  	credits += OCFS2_TRUNCATE_LOG_UPDATE;
  
  	credits += ocfs2_quota_trans_credits(sb);
  
  	return credits;
  }
  
  static inline int ocfs2_jbd2_file_inode(handle_t *handle, struct inode *inode)
  {
  	return jbd2_journal_file_inode(handle, &OCFS2_I(inode)->ip_jinode);
  }
  
  static inline int ocfs2_begin_ordered_truncate(struct inode *inode,
  					       loff_t new_size)
  {
  	return jbd2_journal_begin_ordered_truncate(
  				OCFS2_SB(inode->i_sb)->journal->j_journal,
  				&OCFS2_I(inode)->ip_jinode,
  				new_size);
  }
  
  #endif /* OCFS2_JOURNAL_H */