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no pathname parameter on rename, cleanup rename checks to avoid duplication
with the vfs.

/*
 * Copyright (c) 2000-2002 Silicon Graphics, Inc.  All Rights Reserved.
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 * 
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 * 
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 * 
 * http://www.sgi.com 
 * 
 * For further information regarding this notice, see: 
 * 
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include <xfs.h>


/*
 * Given an array of up to 4 inode pointers, unlock the pointed to inodes.
 * If there are fewer than 4 entries in the array, the empty entries will
 * be at the end and will have NULL pointers in them.
 */
STATIC void
xfs_rename_unlock4(
	xfs_inode_t	**i_tab,
	uint lock_mode)
{
	int	i;

	xfs_iunlock(i_tab[0], lock_mode);
	for (i = 1; i < 4; i++) {
		if (i_tab[i] == NULL) {
			break;
		}
		/*
		 * Watch out for duplicate entries in the table.
		 */
		if (i_tab[i] != i_tab[i-1]) {
			xfs_iunlock(i_tab[i], lock_mode);
		}
	}
}

/*
 * Compare the i_gen fields of the inodes pointed to in the array of
 * inode pointers to the gen values stored at the same offset in the
 * array of generation counts.  Return 0 if they are the same and 1
 * if they are different.
 *
 * There are a maximum of 4 entries in the array.  If there are
 * fewer than that, the first empty entry will have a NULL pointer.
 */
STATIC int
xfs_rename_compare_gencounts(
	xfs_inode_t	**i_tab,
	int		*i_gencounts)
{
	int	i;
	int	compare;

	compare = 0;
	for (i = 0; i < 4; i++) {
		if (i_tab[i] == NULL) {
			break;
		}
		if (i_tab[i]->i_gen != i_gencounts[i]) {
			compare = 1;
			break;
		}
	}
	return compare;
}

#ifdef DEBUG
int xfs_rename_check0, xfs_rename_check1, xfs_rename_check2;
#endif
/*
 * The following routine needs all inodes locked before being called.
 * It checks to see if the inums and names are still valid as passed in.
 *
 * For now, only check if dp1 == dp2.
 *
 * Return 1 if still OK.
 * Return 0 otherwize.
 */
STATIC int
xfs_rename_check_ok(
	xfs_inode_t	*dp1,	/* old (source) directory inode */
	xfs_inode_t	*dp2,	/* new (target) directory inode */
	struct dentry	*dentry1,	/* old entry name */
	struct dentry	*dentry2,	/* new entry name */
	xfs_inode_t	*ip1,	/* inode of old entry */
	xfs_inode_t	*ip2)	/* inode of new entry, if it 
		           	   already existed, NULL otherwise. */
{
	xfs_ino_t		inum1, inum2;
	int			error, diffdirs;

	ASSERT(dp1);
	ASSERT(dp2);
	ASSERT(ip1);
	ASSERT((dp1->i_d.di_mode & IFMT) == IFDIR);
	ASSERT((dp2->i_d.di_mode & IFMT) == IFDIR);

	diffdirs = (dp1 != dp2);

#ifdef DEBUG
	xfs_rename_check0++;
#endif

	if (dp1->i_d.di_nlink == 0 || (diffdirs && (dp2->i_d.di_nlink == 0))) {
		return(0);
	}

	if ((ip1->i_d.di_mode & IFMT) == IFDIR) {
		return(0);
	}

	if (ip2 && ((ip2->i_d.di_mode & IFMT) == IFDIR)) {
		return(0);
	}

	/*
	 * Get the inum for name1 and compare to the value in ip1.
	 * Need to worry about dead-lock here since we have all the inode
	 * locks.
	 */

        error = xfs_dir_lookup_int(XFS_ITOBHV(dp1), DLF_NODNLC,
				   dentry1, &inum1, NULL, NULL);

	if (error) {	/* name1 must be gone or .... */
		return(0);
	}

	if (inum1 != ip1->i_ino) { /* name1 is now a different inode */
		return(0);
	}

#ifdef DEBUG
	xfs_rename_check1++;
#endif

	/*
	 * Get the inum for name2 and compare to the value in ip2.
	 * Need to worry about dead-lock here since we have all the inode
	 * locks.
	 */

        error = xfs_dir_lookup_int(XFS_ITOBHV(dp2), DLF_NODNLC,
				   dentry2, &inum2, NULL, NULL);

	/*
	 * If we have an unsuccessful lookup and ip2 was passed in, the dest is
	 * now gone so we need to start over.
	 * If we have a successful lookup and ip2 was not found before,
	 * we need to start over, too.
	 */
	if ((error && ip2) || (!error && !ip2)) {
		return(0);
	}

	if (ip2 && (inum2 != ip2->i_ino)) {	/* name2 is now a different inode */
		return(0);
	}

#ifdef DEBUG
	xfs_rename_check2++;
#endif
	return(1);
}

#ifdef DEBUG
int xfs_rename_skip, xfs_rename_nskip;
#endif

/*
 * The following routine will acquire the locks required for a rename
 * operation. The code understands the semantics of renames and will
 * validate that name1 exists under dp1 & that name2 may or may not
 * exist under dp2.
 *
 * We are renaming dp1/name1 to dp2/name2.
 *
 * Return ENOENT if dp1 does not exist, other lookup errors, or 0 for success.
 * Return EAGAIN if the caller needs to try again.
 */
STATIC int
xfs_lock_for_rename(
	xfs_inode_t	*dp1,	/* old (source) directory inode */
	xfs_inode_t	*dp2,	/* new (target) directory inode */
	struct dentry	*dentry1, /* old entry name */
	struct dentry	*dentry2, /* new entry name */
	xfs_inode_t	**ipp1,	/* inode of old entry */
	xfs_inode_t	**ipp2,	/* inode of new entry, if it 
		           	   already exists, NULL otherwise. */
	xfs_inode_t	**i_tab,/* array of inode returned, sorted */
	int		*num_inodes,  /* number of inodes in array */
	int		*i_gencounts) /* array of inode gen counts */
{
	xfs_inode_t		*ip1, *ip2, *temp;
	xfs_ino_t		inum1, inum2;
	unsigned long		dir_gen1, dir_gen2;
	int			error;
	int			i, j;
	uint			lock_mode;
	uint			dir_unlocked;
	uint			lookup_flags;
	int			diff_dirs = (dp1 != dp2);

	ip2 = NULL;

	/*
	 * First, find out the current inums of the entries so that we
	 * can determine the initial locking order.  We'll have to 
	 * sanity check stuff after all the locks have been acquired
	 * to see if we still have the right inodes, directories, etc.
	 */
        lock_mode = xfs_ilock_map_shared(dp1);

	/*
	 * We don't want to do lookups in unlinked directories.
	 */
	if (dp1->i_d.di_nlink == 0) {
		xfs_iunlock_map_shared(dp1, lock_mode);
		return XFS_ERROR(ENOENT);
	}

	lookup_flags = DLF_IGET;
	if (lock_mode == XFS_ILOCK_SHARED) {
		lookup_flags |= DLF_LOCK_SHARED;
	}
        error = xfs_dir_lookup_int(XFS_ITOBHV(dp1), lookup_flags,
				   dentry1, &inum1, &ip1, &dir_unlocked);

	/*
	 * Save the current generation so that we can detect if it's
	 * modified between when we drop the lock & reacquire it down
	 * below.  We only need to do this for the src directory since
	 * the target entry does not need to exist yet. 
	 */
	dir_gen1 = dp1->i_gen;

        if (error) {
		xfs_iunlock_map_shared(dp1, lock_mode);
                return error;
	}
	ASSERT (ip1);
	ITRACE(ip1);

	/*
	 * Unlock dp1 and lock dp2 if they are different.
	 */

	if (diff_dirs) {
		xfs_iunlock_map_shared(dp1, lock_mode);
		lock_mode = xfs_ilock_map_shared(dp2);
		/*
		 * We don't want to do lookups in unlinked directories.
		 */
		if (dp2->i_d.di_nlink == 0) {
			xfs_iunlock_map_shared(dp2, lock_mode);
			return XFS_ERROR(ENOENT);
		}
	}


	lookup_flags = DLF_IGET;
	if (lock_mode == XFS_ILOCK_SHARED) {
		lookup_flags |= DLF_LOCK_SHARED;
	}
        error = xfs_dir_lookup_int(XFS_ITOBHV(dp2), lookup_flags,
				   dentry2, &inum2, &ip2, &dir_unlocked);
	dir_gen2 = dp2->i_gen;
	if (error == ENOENT) {		/* target does not need to exist. */
		inum2 = 0;
	} else if (error) {
		/*
		 * If dp2 and dp1 are the same, the next line unlocks dp1.
		 * Got it?
		 */
		xfs_iunlock_map_shared(dp2, lock_mode);
		IRELE (ip1);
                return error;
	} else {
		ITRACE(ip2);
	}

	/*
	 * i_tab contains a list of pointers to inodes.  We initialize
	 * the table here & we'll sort it.  We will then use it to 
	 * order the acquisition of the inode locks.
	 *
	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
	 */
        i_tab[0] = dp1;
        i_tab[1] = dp2;
        i_tab[2] = ip1;
	if (inum2 == 0) {
		*num_inodes = 3;
		i_tab[3] = NULL;
	} else {
		*num_inodes = 4;
        	i_tab[3] = ip2;
	}

	/*
	 * Sort the elements via bubble sort.  (Remember, there are at
	 * most 4 elements to sort, so this is adequate.)
	 */
	for (i=0; i < *num_inodes; i++) {
		for (j=1; j < *num_inodes; j++) {
			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
				temp = i_tab[j];
				i_tab[j] = i_tab[j-1];
				i_tab[j-1] = temp;
			}
		}
	}

	/*
	 * We have dp2 locked. If it isn't first, unlock it.
	 * If it is first, tell xfs_lock_inodes so it can skip it
	 * when locking. if dp1 == dp2, xfs_lock_inodes will skip both
	 * since they are equal. xfs_lock_inodes needs all these inodes
	 * so that it can unlock and retry if there might be a dead-lock
	 * potential with the log.
	 */
	
	if (i_tab[0] == dp2 && lock_mode == XFS_ILOCK_SHARED) {
#ifdef DEBUG
		xfs_rename_skip++;
#endif
		xfs_lock_inodes(i_tab, *num_inodes, 1, XFS_ILOCK_SHARED);
	} else {
#ifdef DEBUG
		xfs_rename_nskip++;
#endif
		xfs_iunlock_map_shared(dp2, lock_mode);
		xfs_lock_inodes(i_tab, *num_inodes, 0, XFS_ILOCK_SHARED);
	}

	/*
	 * See if either of the directories was modified during the
	 * interval between when the locks were released and when
	 * they were reacquired.
	 */
	if (dp1->i_gen != dir_gen1 || (diff_dirs && (dp2->i_gen != dir_gen2))) {
		/*
		 * Someone else may have linked in a new inode
		 * with the same name.  If so, we'll need to
		 * release our locks & go through the whole
		 * thing again.
		 */

		xfs_iunlock(i_tab[0], XFS_ILOCK_SHARED);
		for (i=1; i < *num_inodes; i++) {
			if (i_tab[i] != i_tab[i-1])
				xfs_iunlock(i_tab[i], XFS_ILOCK_SHARED);
		}
		if (*num_inodes == 4) {
			IRELE (ip2);
		}
		IRELE (ip1);
		return XFS_ERROR(EAGAIN);
        }


	/*
	 * Set the return value.  Return the gen counts of the inodes in
	 * i_tab in i_gencounts.  Null out any unused entries in i_tab.
	 */
	*ipp1 = *ipp2 = NULL;
	for (i=0; i < *num_inodes; i++) {
		if (i_tab[i]->i_ino == inum1) {
			*ipp1 = i_tab[i];
		}
		if (i_tab[i]->i_ino == inum2) {
			*ipp2 = i_tab[i];
		}
		i_gencounts[i] = i_tab[i]->i_gen;
	}
	for (;i < 4; i++) {
		i_tab[i] = NULL;
	}
	return 0;
}


int rename_which_error_return = 0;

/*
 * Do all the mundane error checking for xfs_rename().  The code
 * assumes that all of the non-NULL inodes have already been locked.
 */
/*ARGSUSED*/
STATIC int
xfs_rename_error_checks(
	xfs_inode_t	*src_dp,
	xfs_inode_t	*target_dp,
	xfs_inode_t	*src_ip,
	xfs_inode_t	*target_ip,
	char		*src_name,
	char		*target_name,			
	cred_t		*credp,
	int		*status)			
{
	if ((src_ip->i_d.di_mode & IFMT) == IFDIR) {
		/*
		 * Check for link count overflow on target_dp
		 */
		if (target_ip == NULL && (src_dp != target_dp) &&
		    target_dp->i_d.di_nlink >= XFS_MAXLINK) {
			*status = __LINE__;
			return XFS_ERROR(EMLINK);
		}
	}

	*status = 0;
	return 0;
}

/*
 * Perform error checking on the target inode after the ancestor check
 * has been done in xfs_rename().
 */
STATIC int
xfs_rename_target_checks(
	xfs_inode_t	*target_ip,
	int		src_is_directory)
{
	int	error;

	error = 0;
	/*
	 * If target exists and it's a directory, check that both
	 * target and source are directories and that target can be
	 * destroyed, or that neither is a directory.
	 */
	if ((target_ip->i_d.di_mode & IFMT) == IFDIR) {

		/*
		 * Make sure src is a directory.
		 */
		if (!src_is_directory) {
			error = XFS_ERROR(EISDIR);
			rename_which_error_return = __LINE__;
			goto error_return;
		}

		/*
		 * Make sure target dir is empty.
		 */
		if (!(XFS_DIR_ISEMPTY(target_ip->i_mount, target_ip)) || 
		    (target_ip->i_d.di_nlink > 2)) {
			error = XFS_ERROR(EEXIST);
			rename_which_error_return = __LINE__;
			goto error_return;
		}

	} else {

		if (src_is_directory) {
			error = XFS_ERROR(ENOTDIR);
			rename_which_error_return = __LINE__;
			goto error_return;
		}
	}

 error_return:
	return error;
}

#ifdef DEBUG
int xfs_rename_agains;
int xfs_renames;
int xfs_rename_tries;
int xfs_rename_max;
int xfs_rename_big;
int xfs_rename_retries0;
int xfs_rename_retries1;
int xfs_rename_retries2;
int xfs_rename_retries3;
#endif

/*
 * xfs_rename
 */
int
xfs_rename(
	bhv_desc_t	*src_dir_bdp,
	struct dentry	*src_dentry,
	vnode_t		*target_dir_vp,
	struct dentry	*target_dentry,
	cred_t		*credp)
{
	xfs_trans_t	*tp;
	xfs_inode_t	*src_dp, *target_dp, *src_ip, *target_ip;
	xfs_mount_t	*mp;
	int		new_parent;		/* moving to a new dir */
	int		src_is_directory;	/* src_name is a directory */
	int		error;		
        xfs_bmap_free_t free_list;
        xfs_fsblock_t   first_block;
	int		cancel_flags;
	int		committed;
	int		status;
	xfs_inode_t	*inodes[4];
	int		gencounts[4];
	int		target_ip_dropped = 0;	/* dropped target_ip link? */
	vnode_t 	*src_dir_vp;
	bhv_desc_t	*target_dir_bdp;
	int		spaceres;
	int 		target_link_zero = 0;
	int		num_inodes;
	char		*src_name = (char *)src_dentry->d_name.name;
	char		*target_name = (char *)target_dentry->d_name.name;
	int		src_namelen;
	int		target_namelen;
#ifdef DEBUG
	int		retries;

	xfs_renames++;
#endif
	src_dir_vp = BHV_TO_VNODE(src_dir_bdp);
	vn_trace_entry(src_dir_vp, "xfs_rename", (inst_t *)__return_address);
	vn_trace_entry(target_dir_vp, "xfs_rename", (inst_t *)__return_address);

	/*
	 * Find the XFS behavior descriptor for the target directory
	 * vnode since it was not handed to us.
	 */
	target_dir_bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(target_dir_vp), 
						&xfs_vnodeops);
	if (target_dir_bdp == NULL) {
		return XFS_ERROR(EXDEV);
	}
	src_namelen = src_dentry->d_name.len;
	if (src_namelen >= MAXNAMELEN)
		return XFS_ERROR(ENAMETOOLONG);
	target_namelen = target_dentry->d_name.len;
	if (target_namelen >= MAXNAMELEN)
		return XFS_ERROR(ENAMETOOLONG);
	src_dp = XFS_BHVTOI(src_dir_bdp);
        target_dp = XFS_BHVTOI(target_dir_bdp);
	if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_RENAME) ||
	    DM_EVENT_ENABLED(target_dir_vp->v_vfsp,
			     	target_dp, DM_EVENT_RENAME)) {
		error = dm_send_namesp_event(DM_EVENT_RENAME,
					src_dir_bdp, DM_RIGHT_NULL,
					target_dir_bdp, DM_RIGHT_NULL,
					src_name, target_name,
					0, 0, 0);
		if (error) {
			return error;
		}
	}
	/* Return through std_return after this point. */

#ifdef DEBUG
 	retries = 0;
#endif
 start_over:
	/*
	 * Lock all the participating inodes. Depending upon whether
	 * the target_name exists in the target directory, and
	 * whether the target directory is the same as the source
	 * directory, we can lock from 2 to 4 inodes.
	 * xfs_lock_for_rename() will return ENOENT if src_name
	 * does not exist in the source directory.
	 */
	tp = NULL;
	do {
		error = xfs_lock_for_rename(src_dp, target_dp, src_dentry,
				target_dentry, &src_ip, &target_ip, inodes,
				&num_inodes, gencounts);
#ifdef DEBUG
		if (error == EAGAIN) xfs_rename_agains++;
#endif
	} while (error == EAGAIN);
	if (error) {
		rename_which_error_return = __LINE__;
		/*
		 * We have nothing locked, no inode references, and
		 * no transaction, so just get out.
		 */
		goto std_return;
	}

	ASSERT(src_ip != NULL);

	error = xfs_rename_error_checks(src_dp, target_dp, src_ip,
			target_ip, src_name, target_name, credp, &status);
	if (error || status) {
		rename_which_error_return = status;
		xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
		goto rele_return;
	}

	new_parent = (src_dp != target_dp);
	src_is_directory = ((src_ip->i_d.di_mode & IFMT) == IFDIR);

	/*
	 * Drop the locks on our inodes so that we can do the ancestor
	 * check if necessary and start the transaction.  We have already
	 * saved the i_gen fields of each of the inode in the gencounts
	 * array when we called xfs_lock_for_rename().
	 */
	xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);

	XFS_BMAP_INIT(&free_list, &first_block);
	mp = src_dp->i_mount;
	tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
	cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
	spaceres = XFS_RENAME_SPACE_RES(mp, target_namelen);
	error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0,
			XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
	if (error == ENOSPC) {
		spaceres = 0;
		error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
				XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
	}
	if (error) {
		rename_which_error_return = __LINE__;
		xfs_trans_cancel(tp, 0);
                goto rele_return;
	}

	/* 
	 * Attach the dquots to the inodes
	 */
	if (XFS_IS_QUOTA_ON(mp)) {
		if ((error = xfs_qm_vop_rename_dqattach(inodes))) {
			xfs_trans_cancel(tp, cancel_flags);
			rename_which_error_return = __LINE__;
			goto rele_return;
		}
	}

	/*
	 * Reacquire the inode locks we dropped above.  Then check the
	 * generation counts on the inodes.  If any of them have changed,
	 * we cancel the transaction and start over from the top.
	 */
	xfs_lock_inodes(inodes, num_inodes, 0, XFS_ILOCK_EXCL);

	if (xfs_rename_compare_gencounts(inodes, gencounts)) {

		/*
		 * If the ancestors don't need to be checked, see if
		 * the gencount change indicates that we really need
		 * to start over.
		 */

		if(!xfs_rename_check_ok(src_dp, target_dp, src_dentry,
				target_dentry, src_ip, target_ip)) {
			xfs_trans_cancel(tp, cancel_flags);
			xfs_rename_unlock4(inodes, XFS_ILOCK_EXCL);
			IRELE(src_ip);
			if (target_ip != NULL) {
				IRELE(target_ip);
			}
#ifdef DEBUG
			xfs_rename_tries++;
			retries++;
			if (retries > xfs_rename_max)
				xfs_rename_max = retries;
			
			if (retries < 5) xfs_rename_retries0++;
			else if (retries < 100) xfs_rename_retries1++;
			else xfs_rename_retries2++;

			if (retries > 100000) {
				xfs_rename_big++;
			}
#endif
			goto start_over;
#ifdef DEBUG
		} else {
			xfs_rename_retries3++;
#endif
		}
	}

	/*
	 * Join all the inodes to the transaction. From this point on,
	 * we can rely on either trans_commit or trans_cancel to unlock
	 * them.  Note that we need to add a vnode reference to the
	 * directories since trans_commit & trans_cancel will decrement
	 * them when they unlock the inodes.  Also, we need to be careful
	 * not to add an inode to the transaction more than once.
	 */
        VN_HOLD(src_dir_vp);
        xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
        if (new_parent) {
                VN_HOLD(target_dir_vp);
                xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
        }
	if ((src_ip != src_dp) && (src_ip != target_dp)) {
		xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
	}
        if ((target_ip != NULL) &&
	    (target_ip != src_ip) &&
	    (target_ip != src_dp) &&
	    (target_ip != target_dp)) {
                xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
	}

	/*
	 * We should be in the same file system.
	 */
	ASSERT(src_dp->i_mount == target_dp->i_mount);

	/*
	 * We have to redo all of the checks we did above, because we've
	 * unlocked all of the inodes in the interim.
	 */
	error = xfs_rename_error_checks(src_dp, target_dp, src_ip,
			target_ip, src_name, target_name, credp, &status);
	if (error || status) {
		rename_which_error_return = status;
		goto error_return;
	}

	/*
	 * Set up the target.
	 */
	if (target_ip == NULL) {
		/*
		 * If there's no space reservation, check the entry will
		 * fit before actually inserting it.
		 */
		if (spaceres == 0 &&
		    (error = XFS_DIR_CANENTER(mp, tp, target_dp, target_name,
				target_namelen))) {
			rename_which_error_return = __LINE__;
			goto error_return;
		}
		/*
		 * If target does not exist and the rename crosses
		 * directories, adjust the target directory link count
		 * to account for the ".." reference from the new entry.
		 */
		error = XFS_DIR_CREATENAME(mp, tp, target_dp, target_name,
					   target_namelen, src_ip->i_ino,
					   &first_block, &free_list, spaceres);
		if (error == ENOSPC) {
			rename_which_error_return = __LINE__;
			goto error_return;
		}
		if (error) {
			rename_which_error_return = __LINE__;
			goto abort_return;
		}
		xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

		if (new_parent && src_is_directory) {
			error = xfs_bumplink(tp, target_dp);
			if (error) {
				rename_which_error_return = __LINE__;
				goto abort_return;
			}
		}
	} else { /* target_ip != NULL */

		error = xfs_rename_target_checks(target_ip,
						 src_is_directory);
		if (error) {
			goto error_return;
		}

		/*
		 * Link the source inode under the target name.
		 * If the source inode is a directory and we are moving
		 * it across directories, its ".." entry will be 
		 * inconsistent until we replace that down below.
		 *
		 * In case there is already an entry with the same
		 * name at the destination directory, remove it first.
		 */
		error = XFS_DIR_REPLACE(mp, tp, target_dp, target_name,
			target_namelen, src_ip->i_ino, &first_block,
			&free_list, spaceres);
		if (error) {
			rename_which_error_return = __LINE__;
			goto abort_return;
		}
		xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

		/*
		 * Decrement the link count on the target since the target
		 * dir no longer points to it.
		 */
		error = xfs_droplink(tp, target_ip);
		if (error) {
			rename_which_error_return = __LINE__;
			goto abort_return;;
		}
		target_ip_dropped = 1;

		/* Do this test while we still hold the locks */
		target_link_zero = (target_ip)->i_d.di_nlink==0;

		if (src_is_directory) {
			/*
			 * Drop the link from the old "." entry.
			 */
			error = xfs_droplink(tp, target_ip);
			if (error) {
				rename_which_error_return = __LINE__;
				goto abort_return;
			}
		} 

	} /* target_ip != NULL */

	/*
	 * Remove the source.
	 */
	if (new_parent && src_is_directory) {

		/*
		 * Rewrite the ".." entry to point to the new 
	 	 * directory.
		 */
		error = XFS_DIR_REPLACE(mp, tp, src_ip, "..", 2,
					target_dp->i_ino, &first_block,
					&free_list, spaceres);
		ASSERT(error != EEXIST);
		if (error) {
			rename_which_error_return = __LINE__;
			goto abort_return;
		}
		xfs_ichgtime(src_ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

	} else {
		/*
		 * We always want to hit the ctime on the source inode.
		 * We do it in the if clause above for the 'new_parent &&
		 * src_is_directory' case, and here we get all the other
		 * cases.  This isn't strictly required by the standards
		 * since the source inode isn't really being changed,
		 * but old unix file systems did it and some incremental
		 * backup programs won't work without it.
		 */
		xfs_ichgtime(src_ip, XFS_ICHGTIME_CHG);
	}

	/*
	 * Adjust the link count on src_dp.  This is necessary when
	 * renaming a directory, either within one parent when
	 * the target existed, or across two parent directories.
	 */
	if (src_is_directory && (new_parent || target_ip != NULL)) {

		/*
		 * Decrement link count on src_directory since the
		 * entry that's moved no longer points to it.
		 */
		error = xfs_droplink(tp, src_dp);
		if (error) {
			rename_which_error_return = __LINE__;
			goto abort_return;
		}
	}

	error = XFS_DIR_REMOVENAME(mp, tp, src_dp, src_name, src_namelen,
			src_ip->i_ino, &first_block, &free_list, spaceres);
	if (error) {
		rename_which_error_return = __LINE__;
		goto abort_return;
	}
	xfs_ichgtime(src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

	/*
	 * Update the generation counts on all the directory inodes
	 * that we're modifying.
	 */
	src_dp->i_gen++;
	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);

	if (new_parent) {
                target_dp->i_gen++;
                xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
	}

	/*
	 * If there was a target inode, take an extra reference on
	 * it here so that it doesn't go to xfs_inactive() from
	 * within the commit.
	 */
	if (target_ip != NULL) {
		IHOLD(target_ip);
	}

	/*
	 * If this is a synchronous mount, make sure that the
	 * rename transaction goes to disk before returning to
	 * the user.
	 */
	if (mp->m_flags & XFS_MOUNT_WSYNC) {
		xfs_trans_set_sync(tp);
	}

	/*
	 * Take refs. for vop_link_removed calls below.  No need to worry
	 * about directory refs. because the caller holds them.
	 *
	 * Do holds before the xfs_bmap_finish since it might rele them down
	 * to zero.
	 */

	if (target_ip_dropped)
		IHOLD(target_ip);
	IHOLD(src_ip);

	error = xfs_bmap_finish(&tp, &free_list, first_block, &committed);
	if (error) {
		xfs_bmap_cancel(&free_list);
		xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
				 XFS_TRANS_ABORT));
		if (target_ip != NULL) {
			IRELE(target_ip);
		}
		if (target_ip_dropped) {
			IRELE(target_ip);
		}
		IRELE(src_ip);
		goto std_return;
	}

	/*
	 * trans_commit will unlock src_ip, target_ip & decrement
	 * the vnode references.
	 */
	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
	if (target_ip != NULL) {
		xfs_refcache_purge_ip(target_ip);
		IRELE(target_ip);
	}
	/*
	 * Let interposed file systems know about removed links.
	 */
	if (target_ip_dropped) {
		VOP_LINK_REMOVED(XFS_ITOV(target_ip), target_dir_vp, 
					target_link_zero);
		IRELE(target_ip);
	}

	FSC_NOTIFY_NAME_CHANGED(XFS_ITOV(src_ip));

	IRELE(src_ip);

	/* Fall through to std_return with error = 0 or errno from
	 * xfs_trans_commit	 */
std_return:
	if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_POSTRENAME) ||
	    DM_EVENT_ENABLED(target_dir_vp->v_vfsp,
			     	target_dp, DM_EVENT_POSTRENAME)) {
		(void) dm_send_namesp_event(DM_EVENT_POSTRENAME,
					src_dir_bdp, DM_RIGHT_NULL,
					target_dir_bdp, DM_RIGHT_NULL,
					src_name, target_name,
					0, error, 0);
	}
	return error;

 abort_return:
	cancel_flags |= XFS_TRANS_ABORT;
	/* FALLTHROUGH */
 error_return:
	xfs_bmap_cancel(&free_list);
	xfs_trans_cancel(tp, cancel_flags);
	goto std_return;

 rele_return:
	IRELE(src_ip);
	if (target_ip != NULL) {
		IRELE(target_ip);
	}
	goto std_return;
}