xfs: don't complain about unfixed metadata when repairs were injected

While debugging other parts of online repair, I noticed that if someone
injects FORCE_SCRUB_REPAIR, starts an IFLAG_REPAIR scrub on a piece of
metadata, and the metadata repair fails, we'll log a message about
uncorrected errors in the filesystem.

This isn't strictly true if the scrub function didn't set OFLAG_CORRUPT
and we're only doing the repair because the error injection knob is set.
Repair functions are allowed to abort the entire operation at any point
before committing new metadata, in which case the piece of metadata is
in the same state as it was before.  Therefore, the log message should
be gated on the results of the scrub.  Refactor the predicate and
rearrange the code flow to make this happen.

Note: If the repair function errors out after it commits the new
metadata, the transaction cancellation will shut down the filesystem,
which is an obvious sign of corrupt metadata.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/scrub/common.h

@@ -167,6 +167,18 @@ static inline bool xchk_skip_xref(struct xfs_scrub_metadata *sm)
 			       XFS_SCRUB_OFLAG_XCORRUPT);
 }
 
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+/* Decide if a repair is required. */
+static inline bool xchk_needs_repair(const struct xfs_scrub_metadata *sm)
+{
+	return sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+			       XFS_SCRUB_OFLAG_XCORRUPT |
+			       XFS_SCRUB_OFLAG_PREEN);
+}
+#else
+# define xchk_needs_repair(sc)		(false)
+#endif /* CONFIG_XFS_ONLINE_REPAIR */
+
 int xchk_metadata_inode_forks(struct xfs_scrub *sc);
 
 /*

fs/xfs/scrub/scrub.c

@@ -535,15 +535,12 @@ xfs_scrub_metadata(
 
 	if ((sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
 	    !(sc->flags & XREP_ALREADY_FIXED)) {
-		bool needs_fix;
+		bool needs_fix = xchk_needs_repair(sc->sm);
 
 		/* Let debug users force us into the repair routines. */
 		if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
-			sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+			needs_fix = true;
 
-		needs_fix = (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
-						 XFS_SCRUB_OFLAG_XCORRUPT |
-						 XFS_SCRUB_OFLAG_PREEN));
 		/*
 		 * If userspace asked for a repair but it wasn't necessary,
 		 * report that back to userspace.