/*

   * Copyright (c) 2000-2002,2005 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_bit.h"

  #include "xfs_log.h"

  #include "xfs_inum.h"

  #include "xfs_trans.h"

  #include "xfs_sb.h"

  #include "xfs_ag.h"

  #include "xfs_mount.h"
  #include "xfs_trans_priv.h"

  #include "xfs_bmap_btree.h"

  #include "xfs_dinode.h"

  #include "xfs_inode.h"

  #include "xfs_inode_item.h"

  #include "xfs_error.h"

  #include "xfs_trace.h"

  
  
  kmem_zone_t	*xfs_ili_zone;		/* inode log item zone */

  static inline struct xfs_inode_log_item *INODE_ITEM(struct xfs_log_item *lip)
  {
  	return container_of(lip, struct xfs_inode_log_item, ili_item);
  }

  /*
   * This returns the number of iovecs needed to log the given inode item.
   *
   * We need one iovec for the inode log format structure, one for the
   * inode core, and possibly one for the inode data/extents/b-tree root
   * and one for the inode attribute data/extents/b-tree root.
   */
  STATIC uint
  xfs_inode_item_size(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;
  	uint			nvecs = 2;

  
  	/*
  	 * Only log the data/extents/b-tree root if there is something
  	 * left to log.
  	 */
  	iip->ili_format.ilf_fields |= XFS_ILOG_CORE;
  
  	switch (ip->i_d.di_format) {
  	case XFS_DINODE_FMT_EXTENTS:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_DEXT) &&
  		    (ip->i_d.di_nextents > 0) &&
  		    (ip->i_df.if_bytes > 0)) {
  			ASSERT(ip->i_df.if_u1.if_extents != NULL);
  			nvecs++;
  		} else {
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_DEXT;
  		}
  		break;
  
  	case XFS_DINODE_FMT_BTREE:
  		ASSERT(ip->i_df.if_ext_max ==
  		       XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t));
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_DDATA | XFS_ILOG_DEXT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) &&
  		    (ip->i_df.if_broot_bytes > 0)) {
  			ASSERT(ip->i_df.if_broot != NULL);
  			nvecs++;
  		} else {
  			ASSERT(!(iip->ili_format.ilf_fields &
  				 XFS_ILOG_DBROOT));
  #ifdef XFS_TRANS_DEBUG
  			if (iip->ili_root_size > 0) {
  				ASSERT(iip->ili_root_size ==
  				       ip->i_df.if_broot_bytes);
  				ASSERT(memcmp(iip->ili_orig_root,
  					    ip->i_df.if_broot,
  					    iip->ili_root_size) == 0);
  			} else {
  				ASSERT(ip->i_df.if_broot_bytes == 0);
  			}
  #endif
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_DBROOT;
  		}
  		break;
  
  	case XFS_DINODE_FMT_LOCAL:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_DDATA) &&
  		    (ip->i_df.if_bytes > 0)) {
  			ASSERT(ip->i_df.if_u1.if_data != NULL);
  			ASSERT(ip->i_d.di_size > 0);
  			nvecs++;
  		} else {
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_DDATA;
  		}
  		break;
  
  	case XFS_DINODE_FMT_DEV:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
  			  XFS_ILOG_DEXT | XFS_ILOG_UUID);
  		break;
  
  	case XFS_DINODE_FMT_UUID:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
  			  XFS_ILOG_DEXT | XFS_ILOG_DEV);
  		break;
  
  	default:
  		ASSERT(0);
  		break;
  	}
  
  	/*
  	 * If there are no attributes associated with this file,
  	 * then there cannot be anything more to log.
  	 * Clear all attribute-related log flags.
  	 */
  	if (!XFS_IFORK_Q(ip)) {
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
  		return nvecs;
  	}
  
  	/*
  	 * Log any necessary attribute data.
  	 */
  	switch (ip->i_d.di_aformat) {
  	case XFS_DINODE_FMT_EXTENTS:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_AEXT) &&
  		    (ip->i_d.di_anextents > 0) &&
  		    (ip->i_afp->if_bytes > 0)) {
  			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
  			nvecs++;
  		} else {
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_AEXT;
  		}
  		break;
  
  	case XFS_DINODE_FMT_BTREE:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_ADATA | XFS_ILOG_AEXT);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) &&
  		    (ip->i_afp->if_broot_bytes > 0)) {
  			ASSERT(ip->i_afp->if_broot != NULL);
  			nvecs++;
  		} else {
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_ABROOT;
  		}
  		break;
  
  	case XFS_DINODE_FMT_LOCAL:
  		iip->ili_format.ilf_fields &=
  			~(XFS_ILOG_AEXT | XFS_ILOG_ABROOT);
  		if ((iip->ili_format.ilf_fields & XFS_ILOG_ADATA) &&
  		    (ip->i_afp->if_bytes > 0)) {
  			ASSERT(ip->i_afp->if_u1.if_data != NULL);
  			nvecs++;
  		} else {
  			iip->ili_format.ilf_fields &= ~XFS_ILOG_ADATA;
  		}
  		break;
  
  	default:
  		ASSERT(0);
  		break;
  	}
  
  	return nvecs;
  }
  
  /*

   * xfs_inode_item_format_extents - convert in-core extents to on-disk form
   *
   * For either the data or attr fork in extent format, we need to endian convert
   * the in-core extent as we place them into the on-disk inode. In this case, we
   * need to do this conversion before we write the extents into the log. Because
   * we don't have the disk inode to write into here, we allocate a buffer and
   * format the extents into it via xfs_iextents_copy(). We free the buffer in
   * the unlock routine after the copy for the log has been made.
   *
   * In the case of the data fork, the in-core and on-disk fork sizes can be
   * different due to delayed allocation extents. We only log on-disk extents
   * here, so always use the physical fork size to determine the size of the
   * buffer we need to allocate.
   */
  STATIC void
  xfs_inode_item_format_extents(
  	struct xfs_inode	*ip,
  	struct xfs_log_iovec	*vecp,
  	int			whichfork,
  	int			type)
  {
  	xfs_bmbt_rec_t		*ext_buffer;
  
  	ext_buffer = kmem_alloc(XFS_IFORK_SIZE(ip, whichfork), KM_SLEEP);
  	if (whichfork == XFS_DATA_FORK)
  		ip->i_itemp->ili_extents_buf = ext_buffer;
  	else
  		ip->i_itemp->ili_aextents_buf = ext_buffer;
  
  	vecp->i_addr = ext_buffer;
  	vecp->i_len = xfs_iextents_copy(ip, ext_buffer, whichfork);
  	vecp->i_type = type;
  }
  
  /*

   * This is called to fill in the vector of log iovecs for the
   * given inode log item.  It fills the first item with an inode
   * log format structure, the second with the on-disk inode structure,
   * and a possible third and/or fourth with the inode data/extents/b-tree
   * root and inode attributes data/extents/b-tree root.
   */
  STATIC void
  xfs_inode_item_format(

  	struct xfs_log_item	*lip,
  	struct xfs_log_iovec	*vecp)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;

  	uint			nvecs;

  	size_t			data_bytes;

  	xfs_mount_t		*mp;

  	vecp->i_addr = &iip->ili_format;

  	vecp->i_len  = sizeof(xfs_inode_log_format_t);

  	vecp->i_type = XLOG_REG_TYPE_IFORMAT;

  	vecp++;
  	nvecs	     = 1;
  
  	/*
  	 * Clear i_update_core if the timestamps (or any other
  	 * non-transactional modification) need flushing/logging
  	 * and we're about to log them with the rest of the core.
  	 *
  	 * This is the same logic as xfs_iflush() but this code can't
  	 * run at the same time as xfs_iflush because we're in commit
  	 * processing here and so we have the inode lock held in
  	 * exclusive mode.  Although it doesn't really matter
  	 * for the timestamps if both routines were to grab the
  	 * timestamps or not.  That would be ok.
  	 *
  	 * We clear i_update_core before copying out the data.
  	 * This is for coordination with our timestamp updates
  	 * that don't hold the inode lock. They will always
  	 * update the timestamps BEFORE setting i_update_core,
  	 * so if we clear i_update_core after they set it we
  	 * are guaranteed to see their updates to the timestamps
  	 * either here.  Likewise, if they set it after we clear it
  	 * here, we'll see it either on the next commit of this
  	 * inode or the next time the inode gets flushed via
  	 * xfs_iflush().  This depends on strongly ordered memory
  	 * semantics, but we have that.  We use the SYNCHRONIZE
  	 * macro to make sure that the compiler does not reorder
  	 * the i_update_core access below the data copy below.
  	 */
  	if (ip->i_update_core)  {
  		ip->i_update_core = 0;
  		SYNCHRONIZE();
  	}
  
  	/*

  	 * Make sure to get the latest timestamps from the Linux inode.

  	 */

  	xfs_synchronize_times(ip);

  	vecp->i_addr = &ip->i_d;

  	vecp->i_len  = sizeof(struct xfs_icdinode);

  	vecp->i_type = XLOG_REG_TYPE_ICORE;

  	vecp++;
  	nvecs++;
  	iip->ili_format.ilf_fields |= XFS_ILOG_CORE;
  
  	/*
  	 * If this is really an old format inode, then we need to
  	 * log it as such.  This means that we have to copy the link
  	 * count from the new field to the old.  We don't have to worry
  	 * about the new fields, because nothing trusts them as long as
  	 * the old inode version number is there.  If the superblock already
  	 * has a new version number, then we don't bother converting back.
  	 */
  	mp = ip->i_mount;

  	ASSERT(ip->i_d.di_version == 1 || xfs_sb_version_hasnlink(&mp->m_sb));
  	if (ip->i_d.di_version == 1) {

  		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {

  			/*
  			 * Convert it back.
  			 */
  			ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
  			ip->i_d.di_onlink = ip->i_d.di_nlink;
  		} else {
  			/*
  			 * The superblock version has already been bumped,
  			 * so just make the conversion to the new inode
  			 * format permanent.
  			 */

  			ip->i_d.di_version = 2;

  			ip->i_d.di_onlink = 0;
  			memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
  		}
  	}
  
  	switch (ip->i_d.di_format) {
  	case XFS_DINODE_FMT_EXTENTS:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_DEXT) {
  			ASSERT(ip->i_df.if_bytes > 0);
  			ASSERT(ip->i_df.if_u1.if_extents != NULL);
  			ASSERT(ip->i_d.di_nextents > 0);
  			ASSERT(iip->ili_extents_buf == NULL);

  			ASSERT((ip->i_df.if_bytes /
  				(uint)sizeof(xfs_bmbt_rec_t)) > 0);

  #ifdef XFS_NATIVE_HOST

                         if (ip->i_d.di_nextents == ip->i_df.if_bytes /
                                                 (uint)sizeof(xfs_bmbt_rec_t)) {

  				/*
  				 * There are no delayed allocation
  				 * extents, so just point to the
  				 * real extents array.
  				 */

  				vecp->i_addr = ip->i_df.if_u1.if_extents;

  				vecp->i_len = ip->i_df.if_bytes;

  				vecp->i_type = XLOG_REG_TYPE_IEXT;

  			} else
  #endif
  			{

  				xfs_inode_item_format_extents(ip, vecp,
  					XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);

  			}
  			ASSERT(vecp->i_len <= ip->i_df.if_bytes);
  			iip->ili_format.ilf_dsize = vecp->i_len;
  			vecp++;
  			nvecs++;
  		}
  		break;
  
  	case XFS_DINODE_FMT_BTREE:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_DDATA | XFS_ILOG_DEXT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) {
  			ASSERT(ip->i_df.if_broot_bytes > 0);
  			ASSERT(ip->i_df.if_broot != NULL);

  			vecp->i_addr = ip->i_df.if_broot;

  			vecp->i_len = ip->i_df.if_broot_bytes;

  			vecp->i_type = XLOG_REG_TYPE_IBROOT;

  			vecp++;
  			nvecs++;
  			iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
  		}
  		break;
  
  	case XFS_DINODE_FMT_LOCAL:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
  			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_DDATA) {
  			ASSERT(ip->i_df.if_bytes > 0);
  			ASSERT(ip->i_df.if_u1.if_data != NULL);
  			ASSERT(ip->i_d.di_size > 0);

  			vecp->i_addr = ip->i_df.if_u1.if_data;

  			/*
  			 * Round i_bytes up to a word boundary.
  			 * The underlying memory is guaranteed to
  			 * to be there by xfs_idata_realloc().
  			 */
  			data_bytes = roundup(ip->i_df.if_bytes, 4);
  			ASSERT((ip->i_df.if_real_bytes == 0) ||
  			       (ip->i_df.if_real_bytes == data_bytes));
  			vecp->i_len = (int)data_bytes;

  			vecp->i_type = XLOG_REG_TYPE_ILOCAL;

  			vecp++;
  			nvecs++;
  			iip->ili_format.ilf_dsize = (unsigned)data_bytes;
  		}
  		break;
  
  	case XFS_DINODE_FMT_DEV:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
  			  XFS_ILOG_DDATA | XFS_ILOG_UUID)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
  			iip->ili_format.ilf_u.ilfu_rdev =
  				ip->i_df.if_u2.if_rdev;
  		}
  		break;
  
  	case XFS_DINODE_FMT_UUID:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
  			  XFS_ILOG_DDATA | XFS_ILOG_DEV)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
  			iip->ili_format.ilf_u.ilfu_uuid =
  				ip->i_df.if_u2.if_uuid;
  		}
  		break;
  
  	default:
  		ASSERT(0);
  		break;
  	}
  
  	/*
  	 * If there are no attributes associated with the file,
  	 * then we're done.
  	 * Assert that no attribute-related log flags are set.
  	 */
  	if (!XFS_IFORK_Q(ip)) {

  		iip->ili_format.ilf_size = nvecs;
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
  		return;
  	}
  
  	switch (ip->i_d.di_aformat) {
  	case XFS_DINODE_FMT_EXTENTS:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_AEXT) {

  #ifdef DEBUG

  			int nrecs = ip->i_afp->if_bytes /

  				(uint)sizeof(xfs_bmbt_rec_t);

  			ASSERT(nrecs > 0);
  			ASSERT(nrecs == ip->i_d.di_anextents);

  			ASSERT(ip->i_afp->if_bytes > 0);
  			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
  			ASSERT(ip->i_d.di_anextents > 0);
  #endif

  #ifdef XFS_NATIVE_HOST

  			/*
  			 * There are not delayed allocation extents
  			 * for attributes, so just point at the array.
  			 */

  			vecp->i_addr = ip->i_afp->if_u1.if_extents;

  			vecp->i_len = ip->i_afp->if_bytes;

  			vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;

  #else
  			ASSERT(iip->ili_aextents_buf == NULL);

  			xfs_inode_item_format_extents(ip, vecp,
  					XFS_ATTR_FORK, XLOG_REG_TYPE_IATTR_EXT);

  #endif
  			iip->ili_format.ilf_asize = vecp->i_len;
  			vecp++;
  			nvecs++;
  		}
  		break;
  
  	case XFS_DINODE_FMT_BTREE:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_ADATA | XFS_ILOG_AEXT)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) {
  			ASSERT(ip->i_afp->if_broot_bytes > 0);
  			ASSERT(ip->i_afp->if_broot != NULL);

  			vecp->i_addr = ip->i_afp->if_broot;

  			vecp->i_len = ip->i_afp->if_broot_bytes;

  			vecp->i_type = XLOG_REG_TYPE_IATTR_BROOT;

  			vecp++;
  			nvecs++;
  			iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
  		}
  		break;
  
  	case XFS_DINODE_FMT_LOCAL:
  		ASSERT(!(iip->ili_format.ilf_fields &
  			 (XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
  		if (iip->ili_format.ilf_fields & XFS_ILOG_ADATA) {
  			ASSERT(ip->i_afp->if_bytes > 0);
  			ASSERT(ip->i_afp->if_u1.if_data != NULL);

  			vecp->i_addr = ip->i_afp->if_u1.if_data;

  			/*
  			 * Round i_bytes up to a word boundary.
  			 * The underlying memory is guaranteed to
  			 * to be there by xfs_idata_realloc().
  			 */
  			data_bytes = roundup(ip->i_afp->if_bytes, 4);
  			ASSERT((ip->i_afp->if_real_bytes == 0) ||
  			       (ip->i_afp->if_real_bytes == data_bytes));
  			vecp->i_len = (int)data_bytes;

  			vecp->i_type = XLOG_REG_TYPE_IATTR_LOCAL;

  			vecp++;
  			nvecs++;
  			iip->ili_format.ilf_asize = (unsigned)data_bytes;
  		}
  		break;
  
  	default:
  		ASSERT(0);
  		break;
  	}

  	iip->ili_format.ilf_size = nvecs;
  }
  
  
  /*
   * This is called to pin the inode associated with the inode log

   * item in memory so it cannot be written out.

   */
  STATIC void
  xfs_inode_item_pin(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
  
  	trace_xfs_inode_pin(ip, _RET_IP_);
  	atomic_inc(&ip->i_pincount);

  }
  
  
  /*
   * This is called to unpin the inode associated with the inode log
   * item which was previously pinned with a call to xfs_inode_item_pin().

   *
   * Also wake up anyone in xfs_iunpin_wait() if the count goes to 0.

   */

  STATIC void
  xfs_inode_item_unpin(

  	struct xfs_log_item	*lip,

  	int			remove)

  {

  	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;

  	trace_xfs_inode_unpin(ip, _RET_IP_);

  	ASSERT(atomic_read(&ip->i_pincount) > 0);
  	if (atomic_dec_and_test(&ip->i_pincount))
  		wake_up(&ip->i_ipin_wait);

  }

  /*
   * This is called to attempt to lock the inode associated with this
   * inode log item, in preparation for the push routine which does the actual
   * iflush.  Don't sleep on the inode lock or the flush lock.
   *
   * If the flush lock is already held, indicating that the inode has
   * been or is in the process of being flushed, then (ideally) we'd like to
   * see if the inode's buffer is still incore, and if so give it a nudge.
   * We delay doing so until the pushbuf routine, though, to avoid holding

   * the AIL lock across a call to the blackhole which is the buffer cache.

   * Also we don't want to sleep in any device strategy routines, which can happen
   * if we do the subsequent bawrite in here.
   */
  STATIC uint
  xfs_inode_item_trylock(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;

  	if (xfs_ipincount(ip) > 0)

  		return XFS_ITEM_PINNED;

  	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED))

  		return XFS_ITEM_LOCKED;

  
  	if (!xfs_iflock_nowait(ip)) {
  		/*

  		 * inode has already been flushed to the backing buffer,
  		 * leave it locked in shared mode, pushbuf routine will
  		 * unlock it.

  		 */

  		return XFS_ITEM_PUSHBUF;

  	}
  
  	/* Stale items should force out the iclog */
  	if (ip->i_flags & XFS_ISTALE) {
  		xfs_ifunlock(ip);

  		/*
  		 * we hold the AIL lock - notify the unlock routine of this
  		 * so it doesn't try to get the lock again.
  		 */

  		xfs_iunlock(ip, XFS_ILOCK_SHARED|XFS_IUNLOCK_NONOTIFY);
  		return XFS_ITEM_PINNED;
  	}
  
  #ifdef DEBUG
  	if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
  		ASSERT(iip->ili_format.ilf_fields != 0);
  		ASSERT(iip->ili_logged == 0);

  		ASSERT(lip->li_flags & XFS_LI_IN_AIL);

  	}
  #endif
  	return XFS_ITEM_SUCCESS;
  }
  
  /*
   * Unlock the inode associated with the inode log item.
   * Clear the fields of the inode and inode log item that
   * are specific to the current transaction.  If the
   * hold flags is set, do not unlock the inode.
   */
  STATIC void
  xfs_inode_item_unlock(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;

  	unsigned short		lock_flags;

  	ASSERT(ip->i_itemp != NULL);
  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

  
  	/*
  	 * If the inode needed a separate buffer with which to log
  	 * its extents, then free it now.
  	 */
  	if (iip->ili_extents_buf != NULL) {
  		ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS);
  		ASSERT(ip->i_d.di_nextents > 0);
  		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_DEXT);
  		ASSERT(ip->i_df.if_bytes > 0);

  		kmem_free(iip->ili_extents_buf);

  		iip->ili_extents_buf = NULL;
  	}
  	if (iip->ili_aextents_buf != NULL) {
  		ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS);
  		ASSERT(ip->i_d.di_anextents > 0);
  		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_AEXT);
  		ASSERT(ip->i_afp->if_bytes > 0);

  		kmem_free(iip->ili_aextents_buf);

  		iip->ili_aextents_buf = NULL;
  	}

  	lock_flags = iip->ili_lock_flags;
  	iip->ili_lock_flags = 0;

  	if (lock_flags)

  		xfs_iunlock(ip, lock_flags);

  }
  
  /*

   * This is called to find out where the oldest active copy of the inode log
   * item in the on disk log resides now that the last log write of it completed
   * at the given lsn.  Since we always re-log all dirty data in an inode, the
   * latest copy in the on disk log is the only one that matters.  Therefore,
   * simply return the given lsn.
   *
   * If the inode has been marked stale because the cluster is being freed, we
   * don't want to (re-)insert this inode into the AIL. There is a race condition
   * where the cluster buffer may be unpinned before the inode is inserted into
   * the AIL during transaction committed processing. If the buffer is unpinned
   * before the inode item has been committed and inserted, then it is possible

   * for the buffer to be written and IO completes before the inode is inserted

   * into the AIL. In that case, we'd be inserting a clean, stale inode into the
   * AIL which will never get removed. It will, however, get reclaimed which
   * triggers an assert in xfs_inode_free() complaining about freein an inode
   * still in the AIL.
   *

   * To avoid this, just unpin the inode directly and return a LSN of -1 so the
   * transaction committed code knows that it does not need to do any further
   * processing on the item.

   */

  STATIC xfs_lsn_t
  xfs_inode_item_committed(

  	struct xfs_log_item	*lip,

  	xfs_lsn_t		lsn)
  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;

  	if (xfs_iflags_test(ip, XFS_ISTALE)) {
  		xfs_inode_item_unpin(lip, 0);
  		return -1;
  	}

  	return lsn;

  }
  
  /*

   * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
   * failed to get the inode flush lock but did get the inode locked SHARED.
   * Here we're trying to see if the inode buffer is incore, and if so whether it's

   * marked delayed write. If that's the case, we'll promote it and that will
   * allow the caller to write the buffer by triggering the xfsbufd to run.

   */

  STATIC bool

  xfs_inode_item_pushbuf(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;
  	struct xfs_buf		*bp;

  	bool			ret = true;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));

  
  	/*

  	 * If a flush is not in progress anymore, chances are that the
  	 * inode was taken off the AIL. So, just get out.

  	 */

  	if (completion_done(&ip->i_flush) ||

  	    !(lip->li_flags & XFS_LI_IN_AIL)) {

  		xfs_iunlock(ip, XFS_ILOCK_SHARED);

  		return true;

  	}

  	bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno,
  			iip->ili_format.ilf_len, XBF_TRYLOCK);

  	xfs_iunlock(ip, XFS_ILOCK_SHARED);

  	if (!bp)

  		return true;

  	if (XFS_BUF_ISDELAYWRITE(bp))
  		xfs_buf_delwri_promote(bp);

  	if (xfs_buf_ispinned(bp))
  		ret = false;

  	xfs_buf_relse(bp);

  	return ret;

  }

  /*
   * This is called to asynchronously write the inode associated with this
   * inode log item out to disk. The inode will already have been locked by
   * a successful call to xfs_inode_item_trylock().
   */
  STATIC void
  xfs_inode_item_push(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
  	struct xfs_inode	*ip = iip->ili_inode;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));

  	ASSERT(!completion_done(&ip->i_flush));

  	/*
  	 * Since we were able to lock the inode's flush lock and
  	 * we found it on the AIL, the inode must be dirty.  This
  	 * is because the inode is removed from the AIL while still
  	 * holding the flush lock in xfs_iflush_done().  Thus, if
  	 * we found it in the AIL and were able to obtain the flush
  	 * lock without sleeping, then there must not have been
  	 * anyone in the process of flushing the inode.
  	 */
  	ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) ||
  	       iip->ili_format.ilf_fields != 0);
  
  	/*

  	 * Push the inode to it's backing buffer. This will not remove the
  	 * inode from the AIL - a further push will be required to trigger a
  	 * buffer push. However, this allows all the dirty inodes to be pushed

  	 * to the buffer before it is pushed to disk. The buffer IO completion
  	 * will pull the inode from the AIL, mark it clean and unlock the flush

  	 * lock.

  	 */

  	(void) xfs_iflush(ip, SYNC_TRYLOCK);

  	xfs_iunlock(ip, XFS_ILOCK_SHARED);

  }
  
  /*
   * XXX rcc - this one really has to do something.  Probably needs
   * to stamp in a new field in the incore inode.
   */

  STATIC void
  xfs_inode_item_committing(

  	struct xfs_log_item	*lip,

  	xfs_lsn_t		lsn)
  {

  	INODE_ITEM(lip)->ili_last_lsn = lsn;

  }
  
  /*
   * This is the ops vector shared by all buf log items.
   */

  static const struct xfs_item_ops xfs_inode_item_ops = {

  	.iop_size	= xfs_inode_item_size,
  	.iop_format	= xfs_inode_item_format,
  	.iop_pin	= xfs_inode_item_pin,
  	.iop_unpin	= xfs_inode_item_unpin,
  	.iop_trylock	= xfs_inode_item_trylock,
  	.iop_unlock	= xfs_inode_item_unlock,
  	.iop_committed	= xfs_inode_item_committed,
  	.iop_push	= xfs_inode_item_push,
  	.iop_pushbuf	= xfs_inode_item_pushbuf,
  	.iop_committing = xfs_inode_item_committing

  };
  
  
  /*
   * Initialize the inode log item for a newly allocated (in-core) inode.
   */
  void
  xfs_inode_item_init(

  	struct xfs_inode	*ip,
  	struct xfs_mount	*mp)

  {

  	struct xfs_inode_log_item *iip;

  
  	ASSERT(ip->i_itemp == NULL);
  	iip = ip->i_itemp = kmem_zone_zalloc(xfs_ili_zone, KM_SLEEP);

  	iip->ili_inode = ip;

  	xfs_log_item_init(mp, &iip->ili_item, XFS_LI_INODE,
  						&xfs_inode_item_ops);

  	iip->ili_format.ilf_type = XFS_LI_INODE;
  	iip->ili_format.ilf_ino = ip->i_ino;

  	iip->ili_format.ilf_blkno = ip->i_imap.im_blkno;
  	iip->ili_format.ilf_len = ip->i_imap.im_len;
  	iip->ili_format.ilf_boffset = ip->i_imap.im_boffset;

  }
  
  /*
   * Free the inode log item and any memory hanging off of it.
   */
  void
  xfs_inode_item_destroy(
  	xfs_inode_t	*ip)
  {
  #ifdef XFS_TRANS_DEBUG
  	if (ip->i_itemp->ili_root_size != 0) {

  		kmem_free(ip->i_itemp->ili_orig_root);

  	}
  #endif
  	kmem_zone_free(xfs_ili_zone, ip->i_itemp);
  }
  
  
  /*
   * This is the inode flushing I/O completion routine.  It is called
   * from interrupt level when the buffer containing the inode is
   * flushed to disk.  It is responsible for removing the inode item
   * from the AIL if it has not been re-logged, and unlocking the inode's
   * flush lock.

   *
   * To reduce AIL lock traffic as much as possible, we scan the buffer log item
   * list for other inodes that will run this function. We remove them from the
   * buffer list so we can process all the inode IO completions in one AIL lock
   * traversal.

   */

  void
  xfs_iflush_done(

  	struct xfs_buf		*bp,
  	struct xfs_log_item	*lip)

  {

  	struct xfs_inode_log_item *iip;
  	struct xfs_log_item	*blip;
  	struct xfs_log_item	*next;
  	struct xfs_log_item	*prev;

  	struct xfs_ail		*ailp = lip->li_ailp;

  	int			need_ail = 0;
  
  	/*
  	 * Scan the buffer IO completions for other inodes being completed and
  	 * attach them to the current inode log item.
  	 */

  	blip = bp->b_fspriv;

  	prev = NULL;
  	while (blip != NULL) {
  		if (lip->li_cb != xfs_iflush_done) {
  			prev = blip;
  			blip = blip->li_bio_list;
  			continue;
  		}
  
  		/* remove from list */
  		next = blip->li_bio_list;
  		if (!prev) {

  			bp->b_fspriv = next;

  		} else {
  			prev->li_bio_list = next;
  		}
  
  		/* add to current list */
  		blip->li_bio_list = lip->li_bio_list;
  		lip->li_bio_list = blip;
  
  		/*
  		 * while we have the item, do the unlocked check for needing
  		 * the AIL lock.
  		 */
  		iip = INODE_ITEM(blip);
  		if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn)
  			need_ail++;
  
  		blip = next;
  	}
  
  	/* make sure we capture the state of the initial inode. */
  	iip = INODE_ITEM(lip);
  	if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn)
  		need_ail++;

  
  	/*
  	 * We only want to pull the item from the AIL if it is
  	 * actually there and its location in the log has not
  	 * changed since we started the flush.  Thus, we only bother
  	 * if the ili_logged flag is set and the inode's lsn has not
  	 * changed.  First we check the lsn outside
  	 * the lock since it's cheaper, and then we recheck while
  	 * holding the lock before removing the inode from the AIL.
  	 */

  	if (need_ail) {
  		struct xfs_log_item *log_items[need_ail];
  		int i = 0;

  		spin_lock(&ailp->xa_lock);

  		for (blip = lip; blip; blip = blip->li_bio_list) {
  			iip = INODE_ITEM(blip);
  			if (iip->ili_logged &&
  			    blip->li_lsn == iip->ili_flush_lsn) {
  				log_items[i++] = blip;
  			}
  			ASSERT(i <= need_ail);

  		}

  		/* xfs_trans_ail_delete_bulk() drops the AIL lock. */
  		xfs_trans_ail_delete_bulk(ailp, log_items, i);

  	}

  
  	/*

  	 * clean up and unlock the flush lock now we are done. We can clear the
  	 * ili_last_fields bits now that we know that the data corresponding to
  	 * them is safely on disk.

  	 */

  	for (blip = lip; blip; blip = next) {
  		next = blip->li_bio_list;
  		blip->li_bio_list = NULL;
  
  		iip = INODE_ITEM(blip);
  		iip->ili_logged = 0;
  		iip->ili_last_fields = 0;
  		xfs_ifunlock(iip->ili_inode);
  	}

  }
  
  /*
   * This is the inode flushing abort routine.  It is called
   * from xfs_iflush when the filesystem is shutting down to clean
   * up the inode state.
   * It is responsible for removing the inode item
   * from the AIL if it has not been re-logged, and unlocking the inode's
   * flush lock.
   */
  void
  xfs_iflush_abort(
  	xfs_inode_t		*ip)
  {

  	xfs_inode_log_item_t	*iip = ip->i_itemp;

  	if (iip) {

  		struct xfs_ail	*ailp = iip->ili_item.li_ailp;

  		if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {

  			spin_lock(&ailp->xa_lock);

  			if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {

  				/* xfs_trans_ail_delete() drops the AIL lock. */
  				xfs_trans_ail_delete(ailp, (xfs_log_item_t *)iip);

  			} else

  				spin_unlock(&ailp->xa_lock);

  		}
  		iip->ili_logged = 0;
  		/*
  		 * Clear the ili_last_fields bits now that we know that the
  		 * data corresponding to them is safely on disk.
  		 */
  		iip->ili_last_fields = 0;
  		/*
  		 * Clear the inode logging fields so no more flushes are
  		 * attempted.
  		 */
  		iip->ili_format.ilf_fields = 0;
  	}
  	/*
  	 * Release the inode's flush lock since we're done with it.
  	 */
  	xfs_ifunlock(ip);
  }
  
  void
  xfs_istale_done(

  	struct xfs_buf		*bp,
  	struct xfs_log_item	*lip)

  {

  	xfs_iflush_abort(INODE_ITEM(lip)->ili_inode);

  }

  
  /*
   * convert an xfs_inode_log_format struct from either 32 or 64 bit versions
   * (which can have different field alignments) to the native version
   */
  int
  xfs_inode_item_format_convert(
  	xfs_log_iovec_t		*buf,
  	xfs_inode_log_format_t	*in_f)
  {
  	if (buf->i_len == sizeof(xfs_inode_log_format_32_t)) {

  		xfs_inode_log_format_32_t *in_f32 = buf->i_addr;

  		in_f->ilf_type = in_f32->ilf_type;
  		in_f->ilf_size = in_f32->ilf_size;
  		in_f->ilf_fields = in_f32->ilf_fields;
  		in_f->ilf_asize = in_f32->ilf_asize;
  		in_f->ilf_dsize = in_f32->ilf_dsize;
  		in_f->ilf_ino = in_f32->ilf_ino;
  		/* copy biggest field of ilf_u */
  		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
  		       in_f32->ilf_u.ilfu_uuid.__u_bits,
  		       sizeof(uuid_t));
  		in_f->ilf_blkno = in_f32->ilf_blkno;
  		in_f->ilf_len = in_f32->ilf_len;
  		in_f->ilf_boffset = in_f32->ilf_boffset;
  		return 0;
  	} else if (buf->i_len == sizeof(xfs_inode_log_format_64_t)){

  		xfs_inode_log_format_64_t *in_f64 = buf->i_addr;

  		in_f->ilf_type = in_f64->ilf_type;
  		in_f->ilf_size = in_f64->ilf_size;
  		in_f->ilf_fields = in_f64->ilf_fields;
  		in_f->ilf_asize = in_f64->ilf_asize;
  		in_f->ilf_dsize = in_f64->ilf_dsize;
  		in_f->ilf_ino = in_f64->ilf_ino;
  		/* copy biggest field of ilf_u */
  		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
  		       in_f64->ilf_u.ilfu_uuid.__u_bits,
  		       sizeof(uuid_t));
  		in_f->ilf_blkno = in_f64->ilf_blkno;
  		in_f->ilf_len = in_f64->ilf_len;
  		in_f->ilf_boffset = in_f64->ilf_boffset;
  		return 0;
  	}
  	return EFSCORRUPTED;
  }