xfs: allow bulkstat to return metadata directories

Allow the V5 bulkstat ioctl to return information about metadata
directory files so that xfs_scrub can find and scrub them, since they
are otherwise ordinary directories.

(Metadata files of course require per-file scrub code and hence do not
need exposure.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 29 insertions, 4 deletions

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 37c2b50d877e..1fa1c0564b0c 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -36,6 +36,14 @@ struct xfs_bstat_chunk {
 	struct xfs_bulkstat	*buf;
 };
 
+static inline bool
+want_metadir_file(
+	struct xfs_inode	*ip,
+	struct xfs_ibulk	*breq)
+{
+	return xfs_is_metadir_inode(ip) && (breq->flags & XFS_IBULK_METADIR);
+}
+
 /*
  * Fill out the bulkstat info for a single inode and report it somewhere.
  *
@@ -69,9 +77,6 @@ xfs_bulkstat_one_int(
 	vfsuid_t		vfsuid;
 	vfsgid_t		vfsgid;
 
-	if (xfs_is_sb_inum(mp, ino))
-		goto out_advance;
-
 	error = xfs_iget(mp, tp, ino,
 			 (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
 			 XFS_ILOCK_SHARED, &ip);
@@ -97,8 +102,28 @@ xfs_bulkstat_one_int(
 	vfsuid = i_uid_into_vfsuid(idmap, inode);
 	vfsgid = i_gid_into_vfsgid(idmap, inode);
 
+	/*
+	 * If caller wants files from the metadata directories, push out the
+	 * bare minimum information for enabling scrub.
+	 */
+	if (want_metadir_file(ip, bc->breq)) {
+		memset(buf, 0, sizeof(*buf));
+		buf->bs_ino = ino;
+		buf->bs_gen = inode->i_generation;
+		buf->bs_mode = inode->i_mode & S_IFMT;
+		xfs_bulkstat_health(ip, buf);
+		buf->bs_version = XFS_BULKSTAT_VERSION_V5;
+		xfs_iunlock(ip, XFS_ILOCK_SHARED);
+		xfs_irele(ip);
+
+		error = bc->formatter(bc->breq, buf);
+		if (!error || error == -ECANCELED)
+			goto out_advance;
+		goto out;
+	}
+
 	/* If this is a private inode, don't leak its details to userspace. */
-	if (IS_PRIVATE(inode)) {
+	if (IS_PRIVATE(inode) || xfs_is_sb_inum(mp, ino)) {
 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
 		xfs_irele(ip);
 		error = -EINVAL;