[17/51] xfs_repair: improve rtbitmap discrepancy reporting

Commit Message

Darrick J. Wong Dec. 23, 2024, 10:16 p.m. UTC

From: Darrick J. Wong <[e-mail]>

Improve the reporting of discrepancies in the realtime bitmap and
summary files by creating a separate helper function that will pinpoint
the exact (word) locations of mismatches.  This will help developers to
diagnose problems with the rtgroups feature and users to figure out
exactly what's bad in a filesystem.

Signed-off-by: "Darrick J. Wong" <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 repair/rt.c |   42 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

Patch

diff --git a/repair/rt.c b/repair/rt.c
index 65d6a713f379d2..a3378ef1dd0af2 100644
--- a/repair/rt.c
+++ b/repair/rt.c
@@ -131,6 +131,44 @@  _("couldn't allocate memory for incore realtime summary info.\n"));
 	}
 }
 
+static void
+check_rtwords(
+	struct xfs_mount	*mp,
+	const char		*filename,
+	unsigned long long	bno,
+	void			*ondisk,
+	void			*incore)
+{
+	unsigned int		wordcnt = mp->m_blockwsize;
+	union xfs_rtword_raw	*o = ondisk, *i = incore;
+	int			badstart = -1;
+	unsigned int		j;
+
+	if (memcmp(ondisk, incore, wordcnt << XFS_WORDLOG) == 0)
+		return;
+
+	for (j = 0; j < wordcnt; j++, o++, i++) {
+		if (o->old == i->old) {
+			/* Report a range of inconsistency that just ended. */
+			if (badstart >= 0)
+				do_warn(
+ _("discrepancy in %s at dblock 0x%llx words 0x%x-0x%x/0x%x\n"),
+					filename, bno, badstart, j - 1, wordcnt);
+			badstart = -1;
+			continue;
+		}
+
+		if (badstart == -1)
+			badstart = j;
+	}
+
+	if (badstart >= 0)
+		do_warn(
+ _("discrepancy in %s at dblock 0x%llx words 0x%x-0x%x/0x%x\n"),
+					filename, bno, badstart, wordcnt,
+					wordcnt);
+}
+
 static void
 check_rtfile_contents(
 	struct xfs_mount	*mp,
@@ -203,9 +241,7 @@  check_rtfile_contents(
 			break;
 		}
 
-		if (memcmp(bp->b_addr, buf, mp->m_blockwsize << XFS_WORDLOG))
-			do_warn(_("discrepancy in %s at dblock 0x%llx\n"),
-					filename, (unsigned long long)bno);
+		check_rtwords(mp, filename, bno, bp->b_addr, buf);
 
 		buf += XFS_FSB_TO_B(mp, map.br_blockcount);
 		bno += map.br_blockcount;