/*
 * xfs_rename
 */
int
xfs_rename(
	xfs_inode_t	*src_dp,
	struct xfs_name	*src_name,
	xfs_inode_t	*src_ip,
	xfs_inode_t	*target_dp,
	struct xfs_name	*target_name,
	xfs_inode_t	*target_ip)
{
	xfs_trans_t	*tp = NULL;
	xfs_mount_t	*mp = src_dp->i_mount;
	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;
	xfs_inode_t	*inodes[4];
	int		spaceres;
	int		num_inodes;

	xfs_itrace_entry(src_dp);
	xfs_itrace_entry(target_dp);

	if (DM_EVENT_ENABLED(src_dp, DM_EVENT_RENAME) ||
	    DM_EVENT_ENABLED(target_dp, DM_EVENT_RENAME)) {
		error = XFS_SEND_NAMESP(mp, DM_EVENT_RENAME,
					src_dp, DM_RIGHT_NULL,
					target_dp, DM_RIGHT_NULL,
					src_name->name, target_name->name,
					0, 0, 0);
		if (error)
			return error;
	}
	/* Return through std_return after this point. */

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

	if (src_is_directory) {
		/*
		 * Check for link count overflow on target_dp
		 */
		if (target_ip == NULL && new_parent &&
		    target_dp->i_d.di_nlink >= XFS_MAXLINK) {
			error = XFS_ERROR(EMLINK);
			goto std_return;
		}
	}

	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip,
				inodes, &num_inodes);

	xfs_bmap_init(&free_list, &first_block);
	tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
	cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
	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) {
		xfs_trans_cancel(tp, 0);
		goto std_return;
	}

	/*
	 * Attach the dquots to the inodes
	 */
	if ((error = XFS_QM_DQVOPRENAME(mp, inodes))) {
		xfs_trans_cancel(tp, cancel_flags);
		goto std_return;
	}

	/*
	 * 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_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);

	/*
	 * 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.
	 */
	IHOLD(src_dp);
	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);

	if (new_parent) {
		IHOLD(target_dp);
		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
	}

	IHOLD(src_ip);
	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);

	if (target_ip) {
		IHOLD(target_ip);
		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
	}

	/*
	 * If we are using project inheritance, we only allow renames
	 * into our tree when the project IDs are the same; else the
	 * tree quota mechanism would be circumvented.
	 */
	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
		     (target_dp->i_d.di_projid != src_ip->i_d.di_projid))) {
		error = XFS_ERROR(EXDEV);
		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.
		 */
		error = xfs_dir_canenter(tp, target_dp, target_name, spaceres);
		if (error)
			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(tp, target_dp, target_name,
						src_ip->i_ino, &first_block,
						&free_list, spaceres);
		if (error == ENOSPC)
			goto error_return;
		if (error)
			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)
				goto abort_return;
		}
	} else { /* target_ip != NULL */
		/*
		 * 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 & S_IFMT) == S_IFDIR) {
			/*
			 * Make sure target dir is empty.
			 */
			if (!(xfs_dir_isempty(target_ip)) ||
			    (target_ip->i_d.di_nlink > 2)) {
				error = XFS_ERROR(EEXIST);
				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(tp, target_dp, target_name,
					src_ip->i_ino,
					&first_block, &free_list, spaceres);
		if (error)
			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)
			goto abort_return;

		if (src_is_directory) {
			/*
			 * Drop the link from the old "." entry.
			 */
			error = xfs_droplink(tp, target_ip);
			if (error)
				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(tp, src_ip, &xfs_name_dotdot,
					target_dp->i_ino,
					&first_block, &free_list, spaceres);
		ASSERT(error != EEXIST);
		if (error)
			goto abort_return;
	}

	/*
	 * We always want to hit the ctime on the source inode.
	 *
	 * 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)
			goto abort_return;
	}

	error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
					&first_block, &free_list, spaceres);
	if (error)
		goto abort_return;

	xfs_ichgtime(src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
	if (new_parent)
		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);

	/*
	 * 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_MOUNT_DIRSYNC)) {
		xfs_trans_set_sync(tp);
	}

	error = xfs_bmap_finish(&tp, &free_list, &committed);
	if (error) {
		xfs_bmap_cancel(&free_list);
		xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
				 XFS_TRANS_ABORT));
		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);

	/* Fall through to std_return with error = 0 or errno from
	 * xfs_trans_commit	 */
std_return:
	if (DM_EVENT_ENABLED(src_dp, DM_EVENT_POSTRENAME) ||
	    DM_EVENT_ENABLED(target_dp, DM_EVENT_POSTRENAME)) {
		(void) XFS_SEND_NAMESP (mp, DM_EVENT_POSTRENAME,
					src_dp, DM_RIGHT_NULL,
					target_dp, DM_RIGHT_NULL,
					src_name->name, target_name->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;
}
Beispiel #2
0
/*
 * xfs_rename
 */
int
xfs_rename(
	bhv_desc_t	*src_dir_bdp,
	bhv_vname_t	*src_vname,
	bhv_vnode_t	*target_dir_vp,
	bhv_vname_t	*target_vname,
	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;
	xfs_inode_t	*inodes[4];
	int		target_ip_dropped = 0;	/* dropped target_ip link? */
	bhv_vnode_t	*src_dir_vp;
	int		spaceres;
	int		target_link_zero = 0;
	int		num_inodes;
	char		*src_name = VNAME(src_vname);
	char		*target_name = VNAME(target_vname);
	int		src_namelen = VNAMELEN(src_vname);
	int		target_namelen = VNAMELEN(target_vname);

	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_dp = xfs_vtoi(target_dir_vp);
	if (target_dp == NULL) {
		return XFS_ERROR(EXDEV);
	}

	src_dp = XFS_BHVTOI(src_dir_bdp);
	mp = src_dp->i_mount;

	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 = XFS_SEND_NAMESP(mp, DM_EVENT_RENAME,
					src_dir_vp, DM_RIGHT_NULL,
					target_dir_vp, DM_RIGHT_NULL,
					src_name, target_name,
					0, 0, 0);
		if (error) {
			return error;
		}
	}
	/* Return through std_return after this point. */

	/*
	 * 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;
	error = xfs_lock_for_rename(src_dp, target_dp, src_vname,
			target_vname, &src_ip, &target_ip, inodes,
			&num_inodes);

	if (error) {
		/*
		 * We have nothing locked, no inode references, and
		 * no transaction, so just get out.
		 */
		goto std_return;
	}

	ASSERT(src_ip != NULL);

	if ((src_ip->i_d.di_mode & S_IFMT) == S_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) {
			error = XFS_ERROR(EMLINK);
			xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
			goto rele_return;
		}
	}

	/*
	 * If we are using project inheritance, we only allow renames
	 * into our tree when the project IDs are the same; else the
	 * tree quota mechanism would be circumvented.
	 */
	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
		     (target_dp->i_d.di_projid != src_ip->i_d.di_projid))) {
		error = XFS_ERROR(EXDEV);
		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 & S_IFMT) == S_IFDIR);

	/*
	 * Drop the locks on our inodes so that we can start the transaction.
	 */
	xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);

	XFS_BMAP_INIT(&free_list, &first_block);
	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) {
		xfs_trans_cancel(tp, 0);
		goto rele_return;
	}

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

	/*
	 * Reacquire the inode locks we dropped above.
	 */
	xfs_lock_inodes(inodes, num_inodes, 0, XFS_ILOCK_EXCL);

	/*
	 * 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);
	}

	/*
	 * 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(tp, target_dp, target_name,
						target_namelen)))
			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(tp, target_dp, target_name,
					   target_namelen, src_ip->i_ino,
					   &first_block, &free_list, spaceres);
		if (error == ENOSPC)
			goto error_return;
		if (error)
			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)
				goto abort_return;
		}
	} else { /* target_ip != NULL */
		/*
		 * 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 & S_IFMT) == S_IFDIR) {
			/*
			 * Make sure target dir is empty.
			 */
			if (!(xfs_dir_isempty(target_ip)) ||
			    (target_ip->i_d.di_nlink > 2)) {
				error = XFS_ERROR(EEXIST);
				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(tp, target_dp, target_name,
					target_namelen, src_ip->i_ino,
					&first_block, &free_list, spaceres);
		if (error)
			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)
			goto abort_return;
		target_ip_dropped = 1;

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

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

	} /* 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(tp, src_ip, "..", 2, target_dp->i_ino,
					&first_block, &free_list, spaceres);
		ASSERT(error != EEXIST);
		if (error)
			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)
			goto abort_return;
	}

	error = xfs_dir_removename(tp, src_dp, src_name, src_namelen,
			src_ip->i_ino, &first_block, &free_list, spaceres);
	if (error)
		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_MOUNT_DIRSYNC)) {
		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, &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);
	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) {
		bhv_vop_link_removed(XFS_ITOV(target_ip), target_dir_vp,
					target_link_zero);
		IRELE(target_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) XFS_SEND_NAMESP (mp, DM_EVENT_POSTRENAME,
					src_dir_vp, DM_RIGHT_NULL,
					target_dir_vp, 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;
}