Commit a55712b3 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: create libxfs helper to exchange two directory entries 



Create a new libxfs function to exchange two directory entries.
The upcoming metadata directory feature will need this to replace a
metadata inode directory entry.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 90636e45

fs/xfs/libxfs/xfs_dir2.c

+125 −0
Original line number Diff line number Diff line
@@ -955,3 +955,128 @@ xfs_dir_remove_child( 


	return 0;

}



/*

 * Exchange the entry (@name1, @ip1) in directory @dp1 with the entry (@name2,

 * @ip2) in directory @dp2, and update '..' @ip1 and @ip2's entries as needed.

 * @ip1 and @ip2 need not be of the same type.

 *

 * All inodes must have the ILOCK held, and both entries must already exist.

 */

int

xfs_dir_exchange_children(

	struct xfs_trans	*tp,

	struct xfs_dir_update	*du1,

	struct xfs_dir_update	*du2,

	unsigned int		spaceres)

{

	struct xfs_inode	*dp1 = du1->dp;

	const struct xfs_name	*name1 = du1->name;

	struct xfs_inode	*ip1 = du1->ip;

	struct xfs_inode	*dp2 = du2->dp;

	const struct xfs_name	*name2 = du2->name;

	struct xfs_inode	*ip2 = du2->ip;

	int			ip1_flags = 0;

	int			ip2_flags = 0;

	int			dp2_flags = 0;

	int			error;



	/* Swap inode number for dirent in first parent */

	error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);

	if (error)

		return error;



	/* Swap inode number for dirent in second parent */

	error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);

	if (error)

		return error;



	/*

	 * If we're renaming one or more directories across different parents,

	 * update the respective ".." entries (and link counts) to match the new

	 * parents.

	 */

	if (dp1 != dp2) {

		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;



		if (S_ISDIR(VFS_I(ip2)->i_mode)) {

			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,

						dp1->i_ino, spaceres);

			if (error)

				return error;



			/* transfer ip2 ".." reference to dp1 */

			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {

				error = xfs_droplink(tp, dp2);

				if (error)

					return error;

				xfs_bumplink(tp, dp1);

			}



			/*

			 * Although ip1 isn't changed here, userspace needs

			 * to be warned about the change, so that applications

			 * relying on it (like backup ones), will properly

			 * notify the change

			 */

			ip1_flags |= XFS_ICHGTIME_CHG;

			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;

		}



		if (S_ISDIR(VFS_I(ip1)->i_mode)) {

			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,

						dp2->i_ino, spaceres);

			if (error)

				return error;



			/* transfer ip1 ".." reference to dp2 */

			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {

				error = xfs_droplink(tp, dp1);

				if (error)

					return error;

				xfs_bumplink(tp, dp2);

			}



			/*

			 * Although ip2 isn't changed here, userspace needs

			 * to be warned about the change, so that applications

			 * relying on it (like backup ones), will properly

			 * notify the change

			 */

			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;

			ip2_flags |= XFS_ICHGTIME_CHG;

		}

	}



	if (ip1_flags) {

		xfs_trans_ichgtime(tp, ip1, ip1_flags);

		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);

	}

	if (ip2_flags) {

		xfs_trans_ichgtime(tp, ip2, ip2_flags);

		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);

	}

	if (dp2_flags) {

		xfs_trans_ichgtime(tp, dp2, dp2_flags);

		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);

	}

	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);



	/* Schedule parent pointer replacements */

	if (du1->ppargs) {

		error = xfs_parent_replacename(tp, du1->ppargs, dp1, name1,

				dp2, name2, ip1);

		if (error)

			return error;

	}



	if (du2->ppargs) {

		error = xfs_parent_replacename(tp, du2->ppargs, dp2, name2,

				dp1, name1, ip2);

		if (error)

			return error;

	}



	return 0;

}

fs/xfs/libxfs/xfs_dir2.h

+3 −0
Original line number Diff line number Diff line
@@ -325,4 +325,7 @@ int xfs_dir_add_child(struct xfs_trans *tp, unsigned int resblks, 
int xfs_dir_remove_child(struct xfs_trans *tp, unsigned int resblks,

		struct xfs_dir_update *du);



int xfs_dir_exchange_children(struct xfs_trans *tp, struct xfs_dir_update *du1,

		struct xfs_dir_update *du2, unsigned int spaceres);



#endif	/* __XFS_DIR2_H__ */

fs/xfs/xfs_inode.c

+14 −98
Original line number Diff line number Diff line
@@ -2238,107 +2238,23 @@ xfs_cross_rename( 
	struct xfs_parent_args	*ip2_ppargs,

	int			spaceres)

{

	int			error = 0;

	int			ip1_flags = 0;

	int			ip2_flags = 0;

	int			dp2_flags = 0;



	/* Swap inode number for dirent in first parent */

	error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);

	if (error)

		goto out_trans_abort;



	/* Swap inode number for dirent in second parent */

	error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);

	if (error)

		goto out_trans_abort;



	/*

	 * If we're renaming one or more directories across different parents,

	 * update the respective ".." entries (and link counts) to match the new

	 * parents.

	 */

	if (dp1 != dp2) {

		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;



		if (S_ISDIR(VFS_I(ip2)->i_mode)) {

			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,

						dp1->i_ino, spaceres);

			if (error)

				goto out_trans_abort;



			/* transfer ip2 ".." reference to dp1 */

			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {

				error = xfs_droplink(tp, dp2);

				if (error)

					goto out_trans_abort;

				xfs_bumplink(tp, dp1);

			}



			/*

			 * Although ip1 isn't changed here, userspace needs

			 * to be warned about the change, so that applications

			 * relying on it (like backup ones), will properly

			 * notify the change

			 */

			ip1_flags |= XFS_ICHGTIME_CHG;

			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;

		}



		if (S_ISDIR(VFS_I(ip1)->i_mode)) {

			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,

						dp2->i_ino, spaceres);

			if (error)

				goto out_trans_abort;



			/* transfer ip1 ".." reference to dp2 */

			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {

				error = xfs_droplink(tp, dp1);

				if (error)

					goto out_trans_abort;

				xfs_bumplink(tp, dp2);

			}



			/*

			 * Although ip2 isn't changed here, userspace needs

			 * to be warned about the change, so that applications

			 * relying on it (like backup ones), will properly

			 * notify the change

			 */

			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;

			ip2_flags |= XFS_ICHGTIME_CHG;

		}

	}



	/* Schedule parent pointer replacements */

	if (ip1_ppargs) {

		error = xfs_parent_replacename(tp, ip1_ppargs, dp1, name1, dp2,

				name2, ip1);

		if (error)

			goto out_trans_abort;

	}

	struct xfs_dir_update	du1 = {

		.dp		= dp1,

		.name		= name1,

		.ip		= ip1,

		.ppargs		= ip1_ppargs,

	};

	struct xfs_dir_update	du2 = {

		.dp		= dp2,

		.name		= name2,

		.ip		= ip2,

		.ppargs		= ip2_ppargs,

	};

	int			error;



	if (ip2_ppargs) {

		error = xfs_parent_replacename(tp, ip2_ppargs, dp2, name2, dp1,

				name1, ip2);

	error = xfs_dir_exchange_children(tp, &du1, &du2, spaceres);

	if (error)

		goto out_trans_abort;

	}



	if (ip1_flags) {

		xfs_trans_ichgtime(tp, ip1, ip1_flags);

		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);

	}

	if (ip2_flags) {

		xfs_trans_ichgtime(tp, ip2, ip2_flags);

		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);

	}

	if (dp2_flags) {

		xfs_trans_ichgtime(tp, dp2, dp2_flags);

		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);

	}

	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);



	/*

	 * Inform our hook clients that we've finished an exchange operation as