Commit 679b098b authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: refactor directory tree root predicates 



Metadata directory trees make reasoning about the parent of a file more
difficult.  Traditionally, user files are children of sb_rootino, and
metadata files are "children" of the superblock.  Now, we add a third
possibility -- some metadata files can be children of sb_metadirino, but
the classic ones (rt free space data and quotas) are left alone.

Let's add some helper functions (instead of open-coding the logic
everywhere) to make scrub logic easier to understand.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent be42fc13

fs/xfs/scrub/common.c

+29 −0
Original line number Diff line number Diff line
@@ -1452,3 +1452,32 @@ xchk_inode_is_allocated( 
	rcu_read_unlock();

	return error;

}



/* Is this inode a root directory for either tree? */

bool

xchk_inode_is_dirtree_root(const struct xfs_inode *ip)

{

	struct xfs_mount	*mp = ip->i_mount;



	return ip == mp->m_rootip ||

		(xfs_has_metadir(mp) && ip == mp->m_metadirip);

}



/* Does the superblock point down to this inode? */

bool

xchk_inode_is_sb_rooted(const struct xfs_inode *ip)

{

	return xchk_inode_is_dirtree_root(ip) ||

	       xfs_is_sb_inum(ip->i_mount, ip->i_ino);

}



/* What is the root directory inumber for this inode? */

xfs_ino_t

xchk_inode_rootdir_inum(const struct xfs_inode *ip)

{

	struct xfs_mount	*mp = ip->i_mount;



	if (xfs_is_metadir_inode(ip))

		return mp->m_metadirip->i_ino;

	return mp->m_rootip->i_ino;

}

fs/xfs/scrub/common.h

+4 −0
Original line number Diff line number Diff line
@@ -242,4 +242,8 @@ void xchk_fsgates_enable(struct xfs_scrub *sc, unsigned int scrub_fshooks); 
int xchk_inode_is_allocated(struct xfs_scrub *sc, xfs_agino_t agino,

		bool *inuse);



bool xchk_inode_is_dirtree_root(const struct xfs_inode *ip);

bool xchk_inode_is_sb_rooted(const struct xfs_inode *ip);

xfs_ino_t xchk_inode_rootdir_inum(const struct xfs_inode *ip);



#endif	/* __XFS_SCRUB_COMMON_H__ */

fs/xfs/scrub/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -253,7 +253,7 @@ xchk_dir_actor( 
		 * If this is ".." in the root inode, check that the inum

		 * matches this dir.

		 */

		if (dp->i_ino == mp->m_sb.sb_rootino && ino != dp->i_ino)

		if (xchk_inode_is_dirtree_root(dp) && ino != dp->i_ino)

			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);

	}

fs/xfs/scrub/dir_repair.c

+1 −1
Original line number Diff line number Diff line
@@ -1270,7 +1270,7 @@ xrep_dir_scan_dirtree( 
	int			error;



	/* Roots of directory trees are their own parents. */

	if (sc->ip == sc->mp->m_rootip)

	if (xchk_inode_is_dirtree_root(sc->ip))

		xrep_findparent_scan_found(&rd->pscan, sc->ip->i_ino);



	/*

fs/xfs/scrub/dirtree.c

+14 −1
Original line number Diff line number Diff line
@@ -917,7 +917,7 @@ xchk_dirtree( 
	 * scan, because the hook doesn't detach until after sc->ip gets

	 * released during teardown.

	 */

	dl->root_ino = sc->mp->m_rootip->i_ino;

	dl->root_ino = xchk_inode_rootdir_inum(sc->ip);

	dl->scan_ino = sc->ip->i_ino;



	trace_xchk_dirtree_start(sc->ip, sc->sm, 0);
@@ -983,3 +983,16 @@ xchk_dirtree( 
	trace_xchk_dirtree_done(sc->ip, sc->sm, error);

	return error;

}



/* Does the directory targetted by this scrub have no parents? */

bool

xchk_dirtree_parentless(const struct xchk_dirtree *dl)

{

	struct xfs_scrub	*sc = dl->sc;



	if (xchk_inode_is_dirtree_root(sc->ip))

		return true;

	if (VFS_I(sc->ip)->i_nlink == 0)

		return true;

	return false;

}