// SPDX-License-Identifier: GPL-2.0

  /*

   * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
   * All Rights Reserved.

   */

  #include "xfs.h"

  #include "xfs_fs.h"

  #include "xfs_shared.h"

  #include "xfs_format.h"

  #include "xfs_log_format.h"
  #include "xfs_trans_resv.h"

  #include "xfs_mount.h"

  #include "xfs_trans.h"

  #include "xfs_buf_item.h"

  #include "xfs_trans_priv.h"

  #include "xfs_trace.h"

  /*
   * Check to see if a buffer matching the given parameters is already
   * a part of the given transaction.
   */
  STATIC struct xfs_buf *
  xfs_trans_buf_item_match(
  	struct xfs_trans	*tp,
  	struct xfs_buftarg	*target,

  	struct xfs_buf_map	*map,
  	int			nmaps)

  {

  	struct xfs_log_item	*lip;

  	struct xfs_buf_log_item	*blip;

  	int			len = 0;
  	int			i;
  
  	for (i = 0; i < nmaps; i++)
  		len += map[i].bm_len;

  	list_for_each_entry(lip, &tp->t_items, li_trans) {
  		blip = (struct xfs_buf_log_item *)lip;

  		if (blip->bli_item.li_type == XFS_LI_BUF &&

  		    blip->bli_buf->b_target == target &&

  		    XFS_BUF_ADDR(blip->bli_buf) == map[0].bm_bn &&
  		    blip->bli_buf->b_length == len) {
  			ASSERT(blip->bli_buf->b_map_count == nmaps);

  			return blip->bli_buf;

  		}

  	}
  
  	return NULL;
  }

  /*
   * Add the locked buffer to the transaction.
   *
   * The buffer must be locked, and it cannot be associated with any
   * transaction.
   *
   * If the buffer does not yet have a buf log item associated with it,
   * then allocate one for it.  Then add the buf item to the transaction.
   */
  STATIC void
  _xfs_trans_bjoin(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp,
  	int			reset_recur)
  {
  	struct xfs_buf_log_item	*bip;

  	ASSERT(bp->b_transp == NULL);

  
  	/*

  	 * The xfs_buf_log_item pointer is stored in b_log_item.  If

  	 * it doesn't have one yet, then allocate one and initialize it.
  	 * The checks to see if one is there are in xfs_buf_item_init().
  	 */
  	xfs_buf_item_init(bp, tp->t_mountp);

  	bip = bp->b_log_item;

  	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));

  	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));

  	ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
  	if (reset_recur)
  		bip->bli_recur = 0;
  
  	/*
  	 * Take a reference for this transaction on the buf item.
  	 */
  	atomic_inc(&bip->bli_refcount);
  
  	/*

  	 * Attach the item to the transaction so we can find it in
  	 * xfs_trans_get_buf() and friends.

  	 */

  	xfs_trans_add_item(tp, &bip->bli_item);

  	bp->b_transp = tp;

  
  }
  
  void
  xfs_trans_bjoin(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp)
  {
  	_xfs_trans_bjoin(tp, bp, 0);

  	trace_xfs_trans_bjoin(bp->b_log_item);

  }

  
  /*
   * Get and lock the buffer for the caller if it is not already
   * locked within the given transaction.  If it is already locked
   * within the transaction, just increment its lock recursion count
   * and return a pointer to it.
   *

   * If the transaction pointer is NULL, make this just a normal
   * get_buf() call.
   */

  int

  xfs_trans_get_buf_map(
  	struct xfs_trans	*tp,
  	struct xfs_buftarg	*target,
  	struct xfs_buf_map	*map,
  	int			nmaps,

  	xfs_buf_flags_t		flags,
  	struct xfs_buf		**bpp)

  {
  	xfs_buf_t		*bp;

  	struct xfs_buf_log_item	*bip;

  	int			error;

  	*bpp = NULL;
  	if (!tp)
  		return xfs_buf_get_map(target, map, nmaps, flags, bpp);

  
  	/*
  	 * If we find the buffer in the cache with this transaction
  	 * pointer in its b_fsprivate2 field, then we know we already
  	 * have it locked.  In this case we just increment the lock
  	 * recursion count and return the buffer to the caller.
  	 */

  	bp = xfs_trans_buf_item_match(tp, target, map, nmaps);

  	if (bp != NULL) {

  		ASSERT(xfs_buf_islocked(bp));

  		if (XFS_FORCED_SHUTDOWN(tp->t_mountp)) {
  			xfs_buf_stale(bp);

  			bp->b_flags |= XBF_DONE;

  		}

  		ASSERT(bp->b_transp == tp);

  		bip = bp->b_log_item;

  		ASSERT(bip != NULL);
  		ASSERT(atomic_read(&bip->bli_refcount) > 0);
  		bip->bli_recur++;

  		trace_xfs_trans_get_buf_recur(bip);

  		*bpp = bp;
  		return 0;

  	}

  	error = xfs_buf_get_map(target, map, nmaps, flags, &bp);
  	if (error)

  		return error;

  	ASSERT(!bp->b_error);

  	_xfs_trans_bjoin(tp, bp, 1);

  	trace_xfs_trans_get_buf(bp->b_log_item);

  	*bpp = bp;
  	return 0;

  }
  
  /*

   * Get and lock the superblock buffer for the given transaction.

   */

  struct xfs_buf *

  xfs_trans_getsb(

  	struct xfs_trans	*tp)

  {

  	struct xfs_buf		*bp = tp->t_mountp->m_sb_bp;

  
  	/*

  	 * Just increment the lock recursion count if the buffer is already
  	 * attached to this transaction.

  	 */

  	if (bp->b_transp == tp) {

  		struct xfs_buf_log_item	*bip = bp->b_log_item;

  		ASSERT(bip != NULL);
  		ASSERT(atomic_read(&bip->bli_refcount) > 0);
  		bip->bli_recur++;

  		trace_xfs_trans_getsb_recur(bip);

  	} else {
  		xfs_buf_lock(bp);
  		xfs_buf_hold(bp);
  		_xfs_trans_bjoin(tp, bp, 1);

  		trace_xfs_trans_getsb(bp->b_log_item);
  	}

  	return bp;

  }

  /*
   * Get and lock the buffer for the caller if it is not already
   * locked within the given transaction.  If it has not yet been
   * read in, read it from disk. If it is already locked
   * within the transaction and already read in, just increment its
   * lock recursion count and return a pointer to it.
   *

   * If the transaction pointer is NULL, make this just a normal
   * read_buf() call.
   */
  int

  xfs_trans_read_buf_map(
  	struct xfs_mount	*mp,
  	struct xfs_trans	*tp,
  	struct xfs_buftarg	*target,
  	struct xfs_buf_map	*map,
  	int			nmaps,
  	xfs_buf_flags_t		flags,

  	struct xfs_buf		**bpp,

  	const struct xfs_buf_ops *ops)

  {

  	struct xfs_buf		*bp = NULL;
  	struct xfs_buf_log_item	*bip;

  	int			error;

  	*bpp = NULL;

  	/*
  	 * If we find the buffer in the cache with this transaction
  	 * pointer in its b_fsprivate2 field, then we know we already
  	 * have it locked.  If it is already read in we just increment
  	 * the lock recursion count and return the buffer to the caller.
  	 * If the buffer is not yet read in, then we read it in, increment
  	 * the lock recursion count, and return it to the caller.
  	 */

  	if (tp)
  		bp = xfs_trans_buf_item_match(tp, target, map, nmaps);
  	if (bp) {

  		ASSERT(xfs_buf_islocked(bp));

  		ASSERT(bp->b_transp == tp);

  		ASSERT(bp->b_log_item != NULL);

  		ASSERT(!bp->b_error);

  		ASSERT(bp->b_flags & XBF_DONE);

  		/*
  		 * We never locked this buf ourselves, so we shouldn't
  		 * brelse it either. Just get out.
  		 */
  		if (XFS_FORCED_SHUTDOWN(mp)) {

  			trace_xfs_trans_read_buf_shut(bp, _RET_IP_);

  			return -EIO;

  		}

  		/*
  		 * Check if the caller is trying to read a buffer that is
  		 * already attached to the transaction yet has no buffer ops
  		 * assigned.  Ops are usually attached when the buffer is
  		 * attached to the transaction, or by the read caller if
  		 * special circumstances.  That didn't happen, which is not
  		 * how this is supposed to go.
  		 *
  		 * If the buffer passes verification we'll let this go, but if
  		 * not we have to shut down.  Let the transaction cleanup code
  		 * release this buffer when it kills the tranaction.
  		 */
  		ASSERT(bp->b_ops != NULL);

  		error = xfs_buf_reverify(bp, ops);

  		if (error) {

  			xfs_buf_ioerror_alert(bp, __return_address);

  
  			if (tp->t_flags & XFS_TRANS_DIRTY)
  				xfs_force_shutdown(tp->t_mountp,
  						SHUTDOWN_META_IO_ERROR);
  
  			/* bad CRC means corrupted metadata */
  			if (error == -EFSBADCRC)
  				error = -EFSCORRUPTED;
  			return error;
  		}

  		bip = bp->b_log_item;

  		bip->bli_recur++;
  
  		ASSERT(atomic_read(&bip->bli_refcount) > 0);

  		trace_xfs_trans_read_buf_recur(bip);

  		ASSERT(bp->b_ops != NULL || ops == NULL);

  		*bpp = bp;
  		return 0;
  	}

  	error = xfs_buf_read_map(target, map, nmaps, flags, &bp, ops,
  			__return_address);

  	switch (error) {
  	case 0:
  		break;
  	default:

  		if (tp && (tp->t_flags & XFS_TRANS_DIRTY))

  			xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);

  		/* fall through */
  	case -ENOMEM:
  	case -EAGAIN:

  		return error;
  	}

  
  	if (XFS_FORCED_SHUTDOWN(mp)) {
  		xfs_buf_relse(bp);
  		trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
  		return -EIO;

  	}

  	if (tp) {

  		_xfs_trans_bjoin(tp, bp, 1);

  		trace_xfs_trans_read_buf(bp->b_log_item);

  	}

  	ASSERT(bp->b_ops != NULL || ops == NULL);

  	*bpp = bp;
  	return 0;

  }

  /* Has this buffer been dirtied by anyone? */
  bool
  xfs_trans_buf_is_dirty(
  	struct xfs_buf		*bp)
  {
  	struct xfs_buf_log_item	*bip = bp->b_log_item;
  
  	if (!bip)
  		return false;
  	ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
  	return test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);
  }

  /*

   * Release a buffer previously joined to the transaction. If the buffer is
   * modified within this transaction, decrement the recursion count but do not
   * release the buffer even if the count goes to 0. If the buffer is not modified
   * within the transaction, decrement the recursion count and release the buffer
   * if the recursion count goes to 0.

   *

   * If the buffer is to be released and it was not already dirty before this
   * transaction began, then also free the buf_log_item associated with it.

   *

   * If the transaction pointer is NULL, this is a normal xfs_buf_relse() call.

   */
  void

  xfs_trans_brelse(

  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);
  
  	if (!tp) {

  		xfs_buf_relse(bp);
  		return;
  	}

  	trace_xfs_trans_brelse(bip);

  	ASSERT(bip->bli_item.li_type == XFS_LI_BUF);

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  	/*

  	 * If the release is for a recursive lookup, then decrement the count
  	 * and return.

  	 */
  	if (bip->bli_recur > 0) {
  		bip->bli_recur--;

  		return;
  	}
  
  	/*

  	 * If the buffer is invalidated or dirty in this transaction, we can't

  	 * release it until we commit.
  	 */

  	if (test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags))

  		return;

  	if (bip->bli_flags & XFS_BLI_STALE)

  		return;

  	/*

  	 * Unlink the log item from the transaction and clear the hold flag, if
  	 * set. We wouldn't want the next user of the buffer to get confused.

  	 */

  	ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));

  	xfs_trans_del_item(&bip->bli_item);

  	bip->bli_flags &= ~XFS_BLI_HOLD;

  	/* drop the reference to the bli */
  	xfs_buf_item_put(bip);

  	bp->b_transp = NULL;

  	xfs_buf_relse(bp);

  }
  
  /*

   * Mark the buffer as not needing to be unlocked when the buf item's

   * iop_committing() routine is called.  The buffer must already be locked

   * and associated with the given transaction.
   */
  /* ARGSUSED */
  void

  xfs_trans_bhold(
  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));

  	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  	bip->bli_flags |= XFS_BLI_HOLD;

  	trace_xfs_trans_bhold(bip);

  }
  
  /*

   * Cancel the previous buffer hold request made on this buffer
   * for this transaction.
   */
  void

  xfs_trans_bhold_release(
  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));

  	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);
  	ASSERT(bip->bli_flags & XFS_BLI_HOLD);

  	bip->bli_flags &= ~XFS_BLI_HOLD;

  	trace_xfs_trans_bhold_release(bip);

  }
  
  /*

   * Mark a buffer dirty in the transaction.

   */
  void

  xfs_trans_dirty_buf(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  
  	/*
  	 * Mark the buffer as needing to be written out eventually,
  	 * and set its iodone function to remove the buffer's buf log
  	 * item from the AIL and free it when the buffer is flushed

  	 * to disk.

  	 */

  	bp->b_flags |= XBF_DONE;

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  
  	/*
  	 * If we invalidated the buffer within this transaction, then
  	 * cancel the invalidation now that we're dirtying the buffer
  	 * again.  There are no races with the code in xfs_buf_item_unpin(),
  	 * because we have a reference to the buffer this entire time.
  	 */
  	if (bip->bli_flags & XFS_BLI_STALE) {

  		bip->bli_flags &= ~XFS_BLI_STALE;

  		ASSERT(bp->b_flags & XBF_STALE);
  		bp->b_flags &= ~XBF_STALE;

  		bip->__bli_format.blf_flags &= ~XFS_BLF_CANCEL;

  	}

  	bip->bli_flags |= XFS_BLI_DIRTY | XFS_BLI_LOGGED;

  	tp->t_flags |= XFS_TRANS_DIRTY;

  	set_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);

  }
  
  /*
   * This is called to mark bytes first through last inclusive of the given
   * buffer as needing to be logged when the transaction is committed.
   * The buffer must already be associated with the given transaction.
   *
   * First and last are numbers relative to the beginning of this buffer,
   * so the first byte in the buffer is numbered 0 regardless of the
   * value of b_blkno.
   */
  void
  xfs_trans_log_buf(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp,
  	uint			first,
  	uint			last)
  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  
  	ASSERT(first <= last && last < BBTOB(bp->b_length));

  	ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED));

  
  	xfs_trans_dirty_buf(tp, bp);

  	trace_xfs_trans_log_buf(bip);

  	xfs_buf_item_log(bip, first, last);

  }
  
  
  /*

   * Invalidate a buffer that is being used within a transaction.
   *
   * Typically this is because the blocks in the buffer are being freed, so we
   * need to prevent it from being written out when we're done.  Allowing it
   * to be written again might overwrite data in the free blocks if they are
   * reallocated to a file.

   *

   * We prevent the buffer from being written out by marking it stale.  We can't
   * get rid of the buf log item at this point because the buffer may still be
   * pinned by another transaction.  If that is the case, then we'll wait until
   * the buffer is committed to disk for the last time (we can tell by the ref
   * count) and free it in xfs_buf_item_unpin().  Until that happens we will
   * keep the buffer locked so that the buffer and buf log item are not reused.
   *
   * We also set the XFS_BLF_CANCEL flag in the buf log format structure and log
   * the buf item.  This will be used at recovery time to determine that copies
   * of the buffer in the log before this should not be replayed.
   *
   * We mark the item descriptor and the transaction dirty so that we'll hold
   * the buffer until after the commit.
   *
   * Since we're invalidating the buffer, we also clear the state about which
   * parts of the buffer have been logged.  We also clear the flag indicating
   * that this is an inode buffer since the data in the buffer will no longer
   * be valid.
   *
   * We set the stale bit in the buffer as well since we're getting rid of it.

   */
  void
  xfs_trans_binval(

  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	int			i;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  	trace_xfs_trans_binval(bip);

  	if (bip->bli_flags & XFS_BLI_STALE) {
  		/*
  		 * If the buffer is already invalidated, then
  		 * just return.
  		 */

  		ASSERT(bp->b_flags & XBF_STALE);

  		ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY)));

  		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_INODE_BUF));

  		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLFT_MASK));

  		ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);

  		ASSERT(test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags));

  		ASSERT(tp->t_flags & XFS_TRANS_DIRTY);

  		return;
  	}

  	xfs_buf_stale(bp);

  	bip->bli_flags |= XFS_BLI_STALE;

  	bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY);

  	bip->__bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
  	bip->__bli_format.blf_flags |= XFS_BLF_CANCEL;

  	bip->__bli_format.blf_flags &= ~XFS_BLFT_MASK;

  	for (i = 0; i < bip->bli_format_count; i++) {
  		memset(bip->bli_formats[i].blf_data_map, 0,
  		       (bip->bli_formats[i].blf_map_size * sizeof(uint)));
  	}

  	set_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);

  	tp->t_flags |= XFS_TRANS_DIRTY;

  }
  
  /*

   * This call is used to indicate that the buffer contains on-disk inodes which
   * must be handled specially during recovery.  They require special handling
   * because only the di_next_unlinked from the inodes in the buffer should be
   * recovered.  The rest of the data in the buffer is logged via the inodes
   * themselves.

   *

   * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be
   * transferred to the buffer's log format structure so that we'll know what to
   * do at recovery time.

   */

  void
  xfs_trans_inode_buf(

  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  	bip->bli_flags |= XFS_BLI_INODE_BUF;

  	bp->b_flags |= _XBF_INODES;

  	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);

  }
  
  /*
   * This call is used to indicate that the buffer is going to
   * be staled and was an inode buffer. This means it gets

   * special processing during unpin - where any inodes

   * associated with the buffer should be removed from ail.
   * There is also special processing during recovery,
   * any replay of the inodes in the buffer needs to be
   * prevented as the buffer may have been reused.
   */
  void
  xfs_trans_stale_inode_buf(

  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);
  
  	bip->bli_flags |= XFS_BLI_STALE_INODE;

  	bp->b_flags |= _XBF_INODES;

  	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);

  }

  /*
   * Mark the buffer as being one which contains newly allocated
   * inodes.  We need to make sure that even if this buffer is
   * relogged as an 'inode buf' we still recover all of the inode
   * images in the face of a crash.  This works in coordination with
   * xfs_buf_item_committed() to ensure that the buffer remains in the
   * AIL at its original location even after it has been relogged.
   */
  /* ARGSUSED */
  void
  xfs_trans_inode_alloc_buf(

  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(bp->b_transp == tp);

  	ASSERT(bip != NULL);

  	ASSERT(atomic_read(&bip->bli_refcount) > 0);
  
  	bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;

  	bp->b_flags |= _XBF_INODES;

  	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);

  }

  /*

   * Mark the buffer as ordered for this transaction. This means that the contents
   * of the buffer are not recorded in the transaction but it is tracked in the
   * AIL as though it was. This allows us to record logical changes in
   * transactions rather than the physical changes we make to the buffer without
   * changing writeback ordering constraints of metadata buffers.

   */

  bool

  xfs_trans_ordered_buf(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp)
  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  
  	ASSERT(bp->b_transp == tp);
  	ASSERT(bip != NULL);
  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  
  	if (xfs_buf_item_dirty_format(bip))
  		return false;

  
  	bip->bli_flags |= XFS_BLI_ORDERED;
  	trace_xfs_buf_item_ordered(bip);

  
  	/*
  	 * We don't log a dirty range of an ordered buffer but it still needs
  	 * to be marked dirty and that it has been logged.
  	 */
  	xfs_trans_dirty_buf(tp, bp);

  	return true;

  }
  
  /*

   * Set the type of the buffer for log recovery so that it can correctly identify
   * and hence attach the correct buffer ops to the buffer after replay.
   */
  void
  xfs_trans_buf_set_type(
  	struct xfs_trans	*tp,
  	struct xfs_buf		*bp,

  	enum xfs_blft		type)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	if (!tp)
  		return;

  	ASSERT(bp->b_transp == tp);
  	ASSERT(bip != NULL);
  	ASSERT(atomic_read(&bip->bli_refcount) > 0);

  	xfs_blft_to_flags(&bip->__bli_format, type);

  }

  void
  xfs_trans_buf_copy_type(
  	struct xfs_buf		*dst_bp,
  	struct xfs_buf		*src_bp)
  {

  	struct xfs_buf_log_item	*sbip = src_bp->b_log_item;
  	struct xfs_buf_log_item	*dbip = dst_bp->b_log_item;

  	enum xfs_blft		type;

  	type = xfs_blft_from_flags(&sbip->__bli_format);
  	xfs_blft_to_flags(&dbip->__bli_format, type);

  }

  /*
   * Similar to xfs_trans_inode_buf(), this marks the buffer as a cluster of
   * dquots. However, unlike in inode buffer recovery, dquot buffers get
   * recovered in their entirety. (Hence, no XFS_BLI_DQUOT_ALLOC_BUF flag).
   * The only thing that makes dquot buffers different from regular
   * buffers is that we must not replay dquot bufs when recovering
   * if a _corresponding_ quotaoff has happened. We also have to distinguish
   * between usr dquot bufs and grp dquot bufs, because usr and grp quotas
   * can be turned off independently.
   */
  /* ARGSUSED */
  void
  xfs_trans_dquot_buf(

  	xfs_trans_t		*tp,
  	xfs_buf_t		*bp,
  	uint			type)

  {

  	struct xfs_buf_log_item	*bip = bp->b_log_item;

  	ASSERT(type == XFS_BLF_UDQUOT_BUF ||
  	       type == XFS_BLF_PDQUOT_BUF ||
  	       type == XFS_BLF_GDQUOT_BUF);

  	bip->__bli_format.blf_flags |= type;
  
  	switch (type) {
  	case XFS_BLF_UDQUOT_BUF:
  		type = XFS_BLFT_UDQUOT_BUF;
  		break;
  	case XFS_BLF_PDQUOT_BUF:
  		type = XFS_BLFT_PDQUOT_BUF;
  		break;
  	case XFS_BLF_GDQUOT_BUF:
  		type = XFS_BLFT_GDQUOT_BUF;
  		break;
  	default:
  		type = XFS_BLFT_UNKNOWN_BUF;
  		break;
  	}

  	bp->b_flags |= _XBF_DQUOTS;

  	xfs_trans_buf_set_type(tp, bp, type);

  }