xfs: report ag header corruption errors to the health tracking system

Whenever we encounter a corrupt AG header, we should report that to the
health monitoring system for later reporting.  Buffer readers that don't
respond to corruption events with a _mark_sick call can be detected with
the following script:

#!/bin/bash

# Detect missing calls to xfs_*_mark_sick

filter=cat
tty -s && filter=less

git grep -A10  -E '( = xfs_trans_read_buf| = xfs_buf_read\()' fs/xfs/*.[ch] fs/xfs/libxfs/*.[ch] | awk '
BEGIN {
	ignore = 0;
	lineno = 0;
	delete lines;
}
{
	if ($0 == "--") {
		if (!ignore) {
			for (i = 0; i < lineno; i++) {
				print(lines[i]);
			}
			printf("--\n");
		}
		delete lines;
		lineno = 0;
		ignore = 0;
	} else if ($0 ~ /mark_sick/) {
		ignore = 1;
	} else {
		lines[lineno++] = $0;
	}
}
' | $filter

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

1 files changed, 17 insertions, 0 deletions

diff --git a/fs/xfs/xfs_health.c b/fs/xfs/xfs_health.c
index e727a46a95a4..91a29a8610f6 100644
--- a/fs/xfs/xfs_health.c
+++ b/fs/xfs/xfs_health.c
@@ -201,6 +201,23 @@ xfs_rt_measure_sickness(
 	spin_unlock(&mp->m_sb_lock);
 }
 
+/* Mark unhealthy per-ag metadata given a raw AG number. */
+void
+xfs_agno_mark_sick(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	unsigned int		mask)
+{
+	struct xfs_perag	*pag = xfs_perag_get(mp, agno);
+
+	/* per-ag structure not set up yet? */
+	if (!pag)
+		return;
+
+	xfs_ag_mark_sick(pag, mask);
+	xfs_perag_put(pag);
+}
+
 /* Mark unhealthy per-ag metadata. */
 void
 xfs_ag_mark_sick(