text: /*
   * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   * 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.
   *
   * This program is distributed in the hope that it would 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 the Free Software Foundation,
   * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  #include "xfs.h"
  #include "xfs_fs.h"
  #include "xfs_types.h"
  #include "xfs_log.h"
  #include "xfs_inum.h"
  #include "xfs_trans.h"
  #include "xfs_buf_item.h"
  #include "xfs_sb.h"
  #include "xfs_ag.h"
  #include "xfs_mount.h"
  #include "xfs_trans_priv.h"
  #include "xfs_extfree_item.h"
  
  
  kmem_zone_t	*xfs_efi_zone;
  kmem_zone_t	*xfs_efd_zone;
  
  static inline struct xfs_efi_log_item *EFI_ITEM(struct xfs_log_item *lip)
  {
  	return container_of(lip, struct xfs_efi_log_item, efi_item);
  }
  
  void
  xfs_efi_item_free(
  	struct xfs_efi_log_item	*efip)
  {
  	if (efip->efi_format.efi_nextents > XFS_EFI_MAX_FAST_EXTENTS)
  		kmem_free(efip);
  	else
  		kmem_zone_free(xfs_efi_zone, efip);
  }
  
  /*
   * Freeing the efi requires that we remove it from the AIL if it has already
   * been placed there. However, the EFI may not yet have been placed in the AIL
   * when called by xfs_efi_release() from EFD processing due to the ordering of
   * committed vs unpin operations in bulk insert operations. Hence the
   * test_and_clear_bit(XFS_EFI_COMMITTED) to ensure only the last caller frees
   * the EFI.
   */
  STATIC void
  __xfs_efi_release(
  	struct xfs_efi_log_item	*efip)
  {
  	struct xfs_ail		*ailp = efip->efi_item.li_ailp;
  
  	if (!test_and_clear_bit(XFS_EFI_COMMITTED, &efip->efi_flags)) {
  		spin_lock(&ailp->xa_lock);
  		/* xfs_trans_ail_delete() drops the AIL lock. */
  		xfs_trans_ail_delete(ailp, &efip->efi_item);
  		xfs_efi_item_free(efip);
  	}
  }
  
  /*
   * This returns the number of iovecs needed to log the given efi item.
   * We only need 1 iovec for an efi item.  It just logs the efi_log_format
   * structure.
   */
  STATIC uint
  xfs_efi_item_size(
  	struct xfs_log_item	*lip)
  {
  	return 1;
  }
  
  /*
   * This is called to fill in the vector of log iovecs for the
   * given efi log item. We use only 1 iovec, and we point that
   * at the efi_log_format structure embedded in the efi item.
   * It is at this point that we assert that all of the extent
   * slots in the efi item have been filled.
   */
  STATIC void
  xfs_efi_item_format(
  	struct xfs_log_item	*lip,
  	struct xfs_log_iovec	*log_vector)
  {
  	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
  	uint			size;
  
  	ASSERT(atomic_read(&efip->efi_next_extent) ==
  				efip->efi_format.efi_nextents);
  
  	efip->efi_format.efi_type = XFS_LI_EFI;
  
  	size = sizeof(xfs_efi_log_format_t);
  	size += (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
  	efip->efi_format.efi_size = 1;
  
  	log_vector->i_addr = &efip->efi_format;
  	log_vector->i_len = size;
  	log_vector->i_type = XLOG_REG_TYPE_EFI_FORMAT;
  	ASSERT(size >= sizeof(xfs_efi_log_format_t));
  }
  
  
  /*
   * Pinning has no meaning for an efi item, so just return.
   */
  STATIC void
  xfs_efi_item_pin(
  	struct xfs_log_item	*lip)
  {
  }
  
  /*
   * While EFIs cannot really be pinned, the unpin operation is the last place at
   * which the EFI is manipulated during a transaction.  If we are being asked to
   * remove the EFI it's because the transaction has been cancelled and by
   * definition that means the EFI cannot be in the AIL so remove it from the
   * transaction and free it.  Otherwise coordinate with xfs_efi_release() (via
   * XFS_EFI_COMMITTED) to determine who gets to free the EFI.
   */
  STATIC void
  xfs_efi_item_unpin(
  	struct xfs_log_item	*lip,
  	int			remove)
  {
  	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
  
  	if (remove) {
  		ASSERT(!(lip->li_flags & XFS_LI_IN_AIL));
  		if (lip->li_desc)
  			xfs_trans_del_item(lip);
  		xfs_efi_item_free(efip);
  		return;
  	}
  	__xfs_efi_release(efip);
  }
  
  /*
   * Efi items have no locking or pushing.  However, since EFIs are
   * pulled from the AIL when their corresponding EFDs are committed
   * to disk, their situation is very similar to being pinned.  Return
   * XFS_ITEM_PINNED so that the caller will eventually flush the log.
   * This should help in getting the EFI out of the AIL.
   */
  STATIC uint
  xfs_efi_item_trylock(
  	struct xfs_log_item	*lip)
  {
  	return XFS_ITEM_PINNED;
  }
  
  /*
   * Efi items have no locking, so just return.
   */
  STATIC void
  xfs_efi_item_unlock(
  	struct xfs_log_item	*lip)
  {
  	if (lip->li_flags & XFS_LI_ABORTED)
  		xfs_efi_item_free(EFI_ITEM(lip));
  }
  
  /*
   * The EFI is logged only once and cannot be moved in the log, so simply return
   * the lsn at which it's been logged.  For bulk transaction committed
   * processing, the EFI may be processed but not yet unpinned prior to the EFD
   * being processed. Set the XFS_EFI_COMMITTED flag so this case can be detected
   * when processing the EFD.
   */
  STATIC xfs_lsn_t
  xfs_efi_item_committed(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)
  {
  	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
  
  	set_bit(XFS_EFI_COMMITTED, &efip->efi_flags);
  	return lsn;
  }
  
  /*
   * There isn't much you can do to push on an efi item.  It is simply
   * stuck waiting for all of its corresponding efd items to be
   * committed to disk.
   */
  STATIC void
  xfs_efi_item_push(
  	struct xfs_log_item	*lip)
  {
  }
  
  /*
   * The EFI dependency tracking op doesn't do squat.  It can't because
   * it doesn't know where the free extent is coming from.  The dependency
   * tracking has to be handled by the "enclosing" metadata object.  For
   * example, for inodes, the inode is locked throughout the extent freeing
   * so the dependency should be recorded there.
   */
  STATIC void
  xfs_efi_item_committing(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)
  {
  }
  
  /*
   * This is the ops vector shared by all efi log items.
   */
  static const struct xfs_item_ops xfs_efi_item_ops = {
  	.iop_size	= xfs_efi_item_size,
  	.iop_format	= xfs_efi_item_format,
  	.iop_pin	= xfs_efi_item_pin,
  	.iop_unpin	= xfs_efi_item_unpin,
  	.iop_trylock	= xfs_efi_item_trylock,
  	.iop_unlock	= xfs_efi_item_unlock,
  	.iop_committed	= xfs_efi_item_committed,
  	.iop_push	= xfs_efi_item_push,
  	.iop_committing = xfs_efi_item_committing
  };
  
  
  /*
   * Allocate and initialize an efi item with the given number of extents.
   */
  struct xfs_efi_log_item *
  xfs_efi_init(
  	struct xfs_mount	*mp,
  	uint			nextents)
  
  {
  	struct xfs_efi_log_item	*efip;
  	uint			size;
  
  	ASSERT(nextents > 0);
  	if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
  		size = (uint)(sizeof(xfs_efi_log_item_t) +
  			((nextents - 1) * sizeof(xfs_extent_t)));
  		efip = kmem_zalloc(size, KM_SLEEP);
  	} else {
  		efip = kmem_zone_zalloc(xfs_efi_zone, KM_SLEEP);
  	}
  
  	xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
  	efip->efi_format.efi_nextents = nextents;
  	efip->efi_format.efi_id = (__psint_t)(void*)efip;
  	atomic_set(&efip->efi_next_extent, 0);
  
  	return efip;
  }
  
  /*
   * Copy an EFI format buffer from the given buf, and into the destination
   * EFI format structure.
   * The given buffer can be in 32 bit or 64 bit form (which has different padding),
   * one of which will be the native format for this kernel.
   * It will handle the conversion of formats if necessary.
   */
  int
  xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
  {
  	xfs_efi_log_format_t *src_efi_fmt = buf->i_addr;
  	uint i;
  	uint len = sizeof(xfs_efi_log_format_t) + 
  		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);  
  	uint len32 = sizeof(xfs_efi_log_format_32_t) + 
  		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);  
  	uint len64 = sizeof(xfs_efi_log_format_64_t) + 
  		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);  
  
  	if (buf->i_len == len) {
  		memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
  		return 0;
  	} else if (buf->i_len == len32) {
  		xfs_efi_log_format_32_t *src_efi_fmt_32 = buf->i_addr;
  
  		dst_efi_fmt->efi_type     = src_efi_fmt_32->efi_type;
  		dst_efi_fmt->efi_size     = src_efi_fmt_32->efi_size;
  		dst_efi_fmt->efi_nextents = src_efi_fmt_32->efi_nextents;
  		dst_efi_fmt->efi_id       = src_efi_fmt_32->efi_id;
  		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
  			dst_efi_fmt->efi_extents[i].ext_start =
  				src_efi_fmt_32->efi_extents[i].ext_start;
  			dst_efi_fmt->efi_extents[i].ext_len =
  				src_efi_fmt_32->efi_extents[i].ext_len;
  		}
  		return 0;
  	} else if (buf->i_len == len64) {
  		xfs_efi_log_format_64_t *src_efi_fmt_64 = buf->i_addr;
  
  		dst_efi_fmt->efi_type     = src_efi_fmt_64->efi_type;
  		dst_efi_fmt->efi_size     = src_efi_fmt_64->efi_size;
  		dst_efi_fmt->efi_nextents = src_efi_fmt_64->efi_nextents;
  		dst_efi_fmt->efi_id       = src_efi_fmt_64->efi_id;
  		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
  			dst_efi_fmt->efi_extents[i].ext_start =
  				src_efi_fmt_64->efi_extents[i].ext_start;
  			dst_efi_fmt->efi_extents[i].ext_len =
  				src_efi_fmt_64->efi_extents[i].ext_len;
  		}
  		return 0;
  	}
  	return EFSCORRUPTED;
  }
  
  /*
   * This is called by the efd item code below to release references to the given
   * efi item.  Each efd calls this with the number of extents that it has
   * logged, and when the sum of these reaches the total number of extents logged
   * by this efi item we can free the efi item.
   */
  void
  xfs_efi_release(xfs_efi_log_item_t	*efip,
  		uint			nextents)
  {
  	ASSERT(atomic_read(&efip->efi_next_extent) >= nextents);
  	if (atomic_sub_and_test(nextents, &efip->efi_next_extent))
  		__xfs_efi_release(efip);
  }
  
  static inline struct xfs_efd_log_item *EFD_ITEM(struct xfs_log_item *lip)
  {
  	return container_of(lip, struct xfs_efd_log_item, efd_item);
  }
  
  STATIC void
  xfs_efd_item_free(struct xfs_efd_log_item *efdp)
  {
  	if (efdp->efd_format.efd_nextents > XFS_EFD_MAX_FAST_EXTENTS)
  		kmem_free(efdp);
  	else
  		kmem_zone_free(xfs_efd_zone, efdp);
  }
  
  /*
   * This returns the number of iovecs needed to log the given efd item.
   * We only need 1 iovec for an efd item.  It just logs the efd_log_format
   * structure.
   */
  STATIC uint
  xfs_efd_item_size(
  	struct xfs_log_item	*lip)
  {
  	return 1;
  }
  
  /*
   * This is called to fill in the vector of log iovecs for the
   * given efd log item. We use only 1 iovec, and we point that
   * at the efd_log_format structure embedded in the efd item.
   * It is at this point that we assert that all of the extent
   * slots in the efd item have been filled.
   */
  STATIC void
  xfs_efd_item_format(
  	struct xfs_log_item	*lip,
  	struct xfs_log_iovec	*log_vector)
  {
  	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
  	uint			size;
  
  	ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);
  
  	efdp->efd_format.efd_type = XFS_LI_EFD;
  
  	size = sizeof(xfs_efd_log_format_t);
  	size += (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
  	efdp->efd_format.efd_size = 1;
  
  	log_vector->i_addr = &efdp->efd_format;
  	log_vector->i_len = size;
  	log_vector->i_type = XLOG_REG_TYPE_EFD_FORMAT;
  	ASSERT(size >= sizeof(xfs_efd_log_format_t));
  }
  
  /*
   * Pinning has no meaning for an efd item, so just return.
   */
  STATIC void
  xfs_efd_item_pin(
  	struct xfs_log_item	*lip)
  {
  }
  
  /*
   * Since pinning has no meaning for an efd item, unpinning does
   * not either.
   */
  STATIC void
  xfs_efd_item_unpin(
  	struct xfs_log_item	*lip,
  	int			remove)
  {
  }
  
  /*
   * Efd items have no locking, so just return success.
   */
  STATIC uint
  xfs_efd_item_trylock(
  	struct xfs_log_item	*lip)
  {
  	return XFS_ITEM_LOCKED;
  }
  
  /*
   * Efd items have no locking or pushing, so return failure
   * so that the caller doesn't bother with us.
   */
  STATIC void
  xfs_efd_item_unlock(
  	struct xfs_log_item	*lip)
  {
  	if (lip->li_flags & XFS_LI_ABORTED)
  		xfs_efd_item_free(EFD_ITEM(lip));
  }
  
  /*
   * When the efd item is committed to disk, all we need to do
   * is delete our reference to our partner efi item and then
   * free ourselves.  Since we're freeing ourselves we must
   * return -1 to keep the transaction code from further referencing
   * this item.
   */
  STATIC xfs_lsn_t
  xfs_efd_item_committed(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)
  {
  	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
  
  	/*
  	 * If we got a log I/O error, it's always the case that the LR with the
  	 * EFI got unpinned and freed before the EFD got aborted.
  	 */
  	if (!(lip->li_flags & XFS_LI_ABORTED))
  		xfs_efi_release(efdp->efd_efip, efdp->efd_format.efd_nextents);
  
  	xfs_efd_item_free(efdp);
  	return (xfs_lsn_t)-1;
  }
  
  /*
   * There isn't much you can do to push on an efd item.  It is simply
   * stuck waiting for the log to be flushed to disk.
   */
  STATIC void
  xfs_efd_item_push(
  	struct xfs_log_item	*lip)
  {
  }
  
  /*
   * The EFD dependency tracking op doesn't do squat.  It can't because
   * it doesn't know where the free extent is coming from.  The dependency
   * tracking has to be handled by the "enclosing" metadata object.  For
   * example, for inodes, the inode is locked throughout the extent freeing
   * so the dependency should be recorded there.
   */
  STATIC void
  xfs_efd_item_committing(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)
  {
  }
  
  /*
   * This is the ops vector shared by all efd log items.
   */
  static const struct xfs_item_ops xfs_efd_item_ops = {
  	.iop_size	= xfs_efd_item_size,
  	.iop_format	= xfs_efd_item_format,
  	.iop_pin	= xfs_efd_item_pin,
  	.iop_unpin	= xfs_efd_item_unpin,
  	.iop_trylock	= xfs_efd_item_trylock,
  	.iop_unlock	= xfs_efd_item_unlock,
  	.iop_committed	= xfs_efd_item_committed,
  	.iop_push	= xfs_efd_item_push,
  	.iop_committing = xfs_efd_item_committing
  };
  
  /*
   * Allocate and initialize an efd item with the given number of extents.
   */
  struct xfs_efd_log_item *
  xfs_efd_init(
  	struct xfs_mount	*mp,
  	struct xfs_efi_log_item	*efip,
  	uint			nextents)
  
  {
  	struct xfs_efd_log_item	*efdp;
  	uint			size;
  
  	ASSERT(nextents > 0);
  	if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
  		size = (uint)(sizeof(xfs_efd_log_item_t) +
  			((nextents - 1) * sizeof(xfs_extent_t)));
  		efdp = kmem_zalloc(size, KM_SLEEP);
  	} else {
  		efdp = kmem_zone_zalloc(xfs_efd_zone, KM_SLEEP);
  	}
  
  	xfs_log_item_init(mp, &efdp->efd_item, XFS_LI_EFD, &xfs_efd_item_ops);
  	efdp->efd_efip = efip;
  	efdp->efd_format.efd_nextents = nextents;
  	efdp->efd_format.efd_efi_id = efip->efi_format.efi_id;
  
  	return efdp;
  }
  