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_format.h"
  #include "xfs_log_format.h"
  #include "xfs_trans_resv.h"
  #include "xfs_bit.h"
  #include "xfs_mount.h"
  #include "xfs_trans.h"
  #include "xfs_trans_priv.h"
  #include "xfs_buf_item.h"
  #include "xfs_extfree_item.h"
  #include "xfs_log.h"
  #include "xfs_btree.h"
  #include "xfs_rmap.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)
  {
  	kmem_free(efip->efi_item.li_lv_shadow);
  	if (efip->efi_format.efi_nextents > XFS_EFI_MAX_FAST_EXTENTS)
  		kmem_free(efip);
  	else
  		kmem_zone_free(xfs_efi_zone, 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 inline int
  xfs_efi_item_sizeof(
  	struct xfs_efi_log_item *efip)
  {
  	return sizeof(struct xfs_efi_log_format) +
  	       (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
  }
  
  STATIC void
  xfs_efi_item_size(
  	struct xfs_log_item	*lip,
  	int			*nvecs,
  	int			*nbytes)
  {
  	*nvecs += 1;
  	*nbytes += xfs_efi_item_sizeof(EFI_ITEM(lip));
  }
  
  /*
   * 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_vec	*lv)
  {
  	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
  	struct xfs_log_iovec	*vecp = NULL;
  
  	ASSERT(atomic_read(&efip->efi_next_extent) ==
  				efip->efi_format.efi_nextents);
  
  	efip->efi_format.efi_type = XFS_LI_EFI;
  	efip->efi_format.efi_size = 1;
  
  	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFI_FORMAT,
  			&efip->efi_format,
  			xfs_efi_item_sizeof(efip));
  }
  
  
  /*
   * Pinning has no meaning for an efi item, so just return.
   */
  STATIC void
  xfs_efi_item_pin(
  	struct xfs_log_item	*lip)
  {
  }
  
  /*
   * The unpin operation is the last place an EFI is manipulated in the log. It is
   * either inserted in the AIL or aborted in the event of a log I/O error. In
   * either case, the EFI transaction has been successfully committed to make it
   * this far. Therefore, we expect whoever committed the EFI to either construct
   * and commit the EFD or drop the EFD's reference in the event of error. Simply
   * drop the log's EFI reference now that the log is done with it.
   */
  STATIC void
  xfs_efi_item_unpin(
  	struct xfs_log_item	*lip,
  	int			remove)
  {
  	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
  	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_push(
  	struct xfs_log_item	*lip,
  	struct list_head	*buffer_list)
  {
  	return XFS_ITEM_PINNED;
  }
  
  /*
   * The EFI has been either committed or aborted if the transaction has been
   * cancelled. If the transaction was cancelled, an EFD isn't going to be
   * constructed and thus we free the EFI here directly.
   */
  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.
   */
  STATIC xfs_lsn_t
  xfs_efi_item_committed(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)
  {
  	return lsn;
  }
  
  /*
   * 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_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 = (uintptr_t)(void *)efip;
  	atomic_set(&efip->efi_next_extent, 0);
  	atomic_set(&efip->efi_refcount, 2);
  
  	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;
  }
  
  /*
   * 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 reference
   * count to ensure only the last caller frees the EFI.
   */
  void
  xfs_efi_release(
  	struct xfs_efi_log_item	*efip)
  {
  	ASSERT(atomic_read(&efip->efi_refcount) > 0);
  	if (atomic_dec_and_test(&efip->efi_refcount)) {
  		xfs_trans_ail_remove(&efip->efi_item, SHUTDOWN_LOG_IO_ERROR);
  		xfs_efi_item_free(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)
  {
  	kmem_free(efdp->efd_item.li_lv_shadow);
  	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 inline int
  xfs_efd_item_sizeof(
  	struct xfs_efd_log_item *efdp)
  {
  	return sizeof(xfs_efd_log_format_t) +
  	       (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
  }
  
  STATIC void
  xfs_efd_item_size(
  	struct xfs_log_item	*lip,
  	int			*nvecs,
  	int			*nbytes)
  {
  	*nvecs += 1;
  	*nbytes += xfs_efd_item_sizeof(EFD_ITEM(lip));
  }
  
  /*
   * 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_vec	*lv)
  {
  	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
  	struct xfs_log_iovec	*vecp = NULL;
  
  	ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);
  
  	efdp->efd_format.efd_type = XFS_LI_EFD;
  	efdp->efd_format.efd_size = 1;
  
  	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFD_FORMAT,
  			&efdp->efd_format,
  			xfs_efd_item_sizeof(efdp));
  }
  
  /*
   * 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)
  {
  }
  
  /*
   * 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 uint
  xfs_efd_item_push(
  	struct xfs_log_item	*lip,
  	struct list_head	*buffer_list)
  {
  	return XFS_ITEM_PINNED;
  }
  
  /*
   * The EFD is either committed or aborted if the transaction is cancelled. If
   * the transaction is cancelled, drop our reference to the EFI and free the EFD.
   */
  STATIC void
  xfs_efd_item_unlock(
  	struct xfs_log_item	*lip)
  {
  	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
  
  	if (lip->li_flags & XFS_LI_ABORTED) {
  		xfs_efi_release(efdp->efd_efip);
  		xfs_efd_item_free(efdp);
  	}
  }
  
  /*
   * 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);
  
  	/*
  	 * Drop the EFI reference regardless of whether the EFD has been
  	 * aborted. Once the EFD transaction is constructed, it is the sole
  	 * responsibility of the EFD to release the EFI (even if the EFI is
  	 * aborted due to log I/O error).
  	 */
  	xfs_efi_release(efdp->efd_efip);
  	xfs_efd_item_free(efdp);
  
  	return (xfs_lsn_t)-1;
  }
  
  /*
   * 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_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;
  }
  
  /*
   * Process an extent free intent item that was recovered from
   * the log.  We need to free the extents that it describes.
   */
  int
  xfs_efi_recover(
  	struct xfs_mount	*mp,
  	struct xfs_efi_log_item	*efip)
  {
  	struct xfs_efd_log_item	*efdp;
  	struct xfs_trans	*tp;
  	int			i;
  	int			error = 0;
  	xfs_extent_t		*extp;
  	xfs_fsblock_t		startblock_fsb;
  	struct xfs_owner_info	oinfo;
  
  	ASSERT(!test_bit(XFS_EFI_RECOVERED, &efip->efi_flags));
  
  	/*
  	 * First check the validity of the extents described by the
  	 * EFI.  If any are bad, then assume that all are bad and
  	 * just toss the EFI.
  	 */
  	for (i = 0; i < efip->efi_format.efi_nextents; i++) {
  		extp = &efip->efi_format.efi_extents[i];
  		startblock_fsb = XFS_BB_TO_FSB(mp,
  				   XFS_FSB_TO_DADDR(mp, extp->ext_start));
  		if (startblock_fsb == 0 ||
  		    extp->ext_len == 0 ||
  		    startblock_fsb >= mp->m_sb.sb_dblocks ||
  		    extp->ext_len >= mp->m_sb.sb_agblocks) {
  			/*
  			 * This will pull the EFI from the AIL and
  			 * free the memory associated with it.
  			 */
  			set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
  			xfs_efi_release(efip);
  			return -EIO;
  		}
  	}
  
  	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
  	if (error)
  		return error;
  	efdp = xfs_trans_get_efd(tp, efip, efip->efi_format.efi_nextents);
  
  	xfs_rmap_skip_owner_update(&oinfo);
  	for (i = 0; i < efip->efi_format.efi_nextents; i++) {
  		extp = &efip->efi_format.efi_extents[i];
  		error = xfs_trans_free_extent(tp, efdp, extp->ext_start,
  					      extp->ext_len, &oinfo);
  		if (error)
  			goto abort_error;
  
  	}
  
  	set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
  	error = xfs_trans_commit(tp);
  	return error;
  
  abort_error:
  	xfs_trans_cancel(tp);
  	return error;
  }
  