xfs: separate the marking of sick and checked metadata

Split the setting of the sick and checked masks into separate functions
as part of preparing to add the ability for regular runtime fs code
(i.e. not scrub) to mark metadata structures sick when corruptions are
found.  Improve the documentation of libxfs' requirements for helper
behavior.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_health.h

@@ -111,24 +111,45 @@ struct xfs_fsop_geom;
 				 XFS_SICK_INO_DIR_ZAPPED | \
 				 XFS_SICK_INO_SYMLINK_ZAPPED)
 
-/* These functions must be provided by the xfs implementation. */
+/*
+ * These functions must be provided by the xfs implementation.  Function
+ * behavior with respect to the first argument should be as follows:
+ *
+ * xfs_*_mark_sick:        Set the sick flags and do not set checked flags.
+ *                         Runtime code should call this upon encountering
+ *                         a corruption.
+ *
+ * xfs_*_mark_corrupt:     Set the sick and checked flags simultaneously.
+ *                         Fsck tools should call this when corruption is
+ *                         found.
+ *
+ * xfs_*_mark_healthy:     Clear the sick flags and set the checked flags.
+ *                         Fsck tools should call this after correcting errors.
+ *
+ * xfs_*_measure_sickness: Return the sick and check status in the provided
+ *                         out parameters.
+ */
 
 void xfs_fs_mark_sick(struct xfs_mount *mp, unsigned int mask);
+void xfs_fs_mark_corrupt(struct xfs_mount *mp, unsigned int mask);
 void xfs_fs_mark_healthy(struct xfs_mount *mp, unsigned int mask);
 void xfs_fs_measure_sickness(struct xfs_mount *mp, unsigned int *sick,
 		unsigned int *checked);
 
 void xfs_rt_mark_sick(struct xfs_mount *mp, unsigned int mask);
+void xfs_rt_mark_corrupt(struct xfs_mount *mp, unsigned int mask);
 void xfs_rt_mark_healthy(struct xfs_mount *mp, unsigned int mask);
 void xfs_rt_measure_sickness(struct xfs_mount *mp, unsigned int *sick,
 		unsigned int *checked);
 
 void xfs_ag_mark_sick(struct xfs_perag *pag, unsigned int mask);
+void xfs_ag_mark_corrupt(struct xfs_perag *pag, unsigned int mask);
 void xfs_ag_mark_healthy(struct xfs_perag *pag, unsigned int mask);
 void xfs_ag_measure_sickness(struct xfs_perag *pag, unsigned int *sick,
 		unsigned int *checked);
 
 void xfs_inode_mark_sick(struct xfs_inode *ip, unsigned int mask);
+void xfs_inode_mark_corrupt(struct xfs_inode *ip, unsigned int mask);
 void xfs_inode_mark_healthy(struct xfs_inode *ip, unsigned int mask);
 void xfs_inode_measure_sickness(struct xfs_inode *ip, unsigned int *sick,
 		unsigned int *checked);

fs/xfs/scrub/health.c

@@ -175,7 +175,7 @@ xchk_update_health(
 	case XHG_AG:
 		pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
 		if (bad)
-			xfs_ag_mark_sick(pag, sc->sick_mask);
+			xfs_ag_mark_corrupt(pag, sc->sick_mask);
 		else
 			xfs_ag_mark_healthy(pag, sc->sick_mask);
 		xfs_perag_put(pag);
@@ -184,19 +184,19 @@ xchk_update_health(
 		if (!sc->ip)
 			return;
 		if (bad)
-			xfs_inode_mark_sick(sc->ip, sc->sick_mask);
+			xfs_inode_mark_corrupt(sc->ip, sc->sick_mask);
 		else
 			xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
 		break;
 	case XHG_FS:
 		if (bad)
-			xfs_fs_mark_sick(sc->mp, sc->sick_mask);
+			xfs_fs_mark_corrupt(sc->mp, sc->sick_mask);
 		else
 			xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
 		break;
 	case XHG_RT:
 		if (bad)
-			xfs_rt_mark_sick(sc->mp, sc->sick_mask);
+			xfs_rt_mark_corrupt(sc->mp, sc->sick_mask);
 		else
 			xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
 		break;

fs/xfs/xfs_health.c

@@ -96,6 +96,20 @@ xfs_fs_mark_sick(
 	ASSERT(!(mask & ~XFS_SICK_FS_PRIMARY));
 	trace_xfs_fs_mark_sick(mp, mask);
 
+	spin_lock(&mp->m_sb_lock);
+	mp->m_fs_sick |= mask;
+	spin_unlock(&mp->m_sb_lock);
+}
+
+/* Mark per-fs metadata as having been checked and found unhealthy by fsck. */
+void
+xfs_fs_mark_corrupt(
+	struct xfs_mount	*mp,
+	unsigned int		mask)
+{
+	ASSERT(!(mask & ~XFS_SICK_FS_PRIMARY));
+	trace_xfs_fs_mark_corrupt(mp, mask);
+
 	spin_lock(&mp->m_sb_lock);
 	mp->m_fs_sick |= mask;
 	mp->m_fs_checked |= mask;
@@ -139,6 +153,20 @@ xfs_rt_mark_sick(
 	ASSERT(!(mask & ~XFS_SICK_RT_PRIMARY));
 	trace_xfs_rt_mark_sick(mp, mask);
 
+	spin_lock(&mp->m_sb_lock);
+	mp->m_rt_sick |= mask;
+	spin_unlock(&mp->m_sb_lock);
+}
+
+/* Mark realtime metadata as having been checked and found unhealthy by fsck. */
+void
+xfs_rt_mark_corrupt(
+	struct xfs_mount	*mp,
+	unsigned int		mask)
+{
+	ASSERT(!(mask & ~XFS_SICK_RT_PRIMARY));
+	trace_xfs_rt_mark_corrupt(mp, mask);
+
 	spin_lock(&mp->m_sb_lock);
 	mp->m_rt_sick |= mask;
 	mp->m_rt_checked |= mask;
@@ -182,6 +210,20 @@ xfs_ag_mark_sick(
 	ASSERT(!(mask & ~XFS_SICK_AG_PRIMARY));
 	trace_xfs_ag_mark_sick(pag->pag_mount, pag->pag_agno, mask);
 
+	spin_lock(&pag->pag_state_lock);
+	pag->pag_sick |= mask;
+	spin_unlock(&pag->pag_state_lock);
+}
+
+/* Mark per-ag metadata as having been checked and found unhealthy by fsck. */
+void
+xfs_ag_mark_corrupt(
+	struct xfs_perag	*pag,
+	unsigned int		mask)
+{
+	ASSERT(!(mask & ~XFS_SICK_AG_PRIMARY));
+	trace_xfs_ag_mark_corrupt(pag->pag_mount, pag->pag_agno, mask);
+
 	spin_lock(&pag->pag_state_lock);
 	pag->pag_sick |= mask;
 	pag->pag_checked |= mask;
@@ -225,6 +267,29 @@ xfs_inode_mark_sick(
 	ASSERT(!(mask & ~(XFS_SICK_INO_PRIMARY | XFS_SICK_INO_ZAPPED)));
 	trace_xfs_inode_mark_sick(ip, mask);
 
+	spin_lock(&ip->i_flags_lock);
+	ip->i_sick |= mask;
+	spin_unlock(&ip->i_flags_lock);
+
+	/*
+	 * Keep this inode around so we don't lose the sickness report.  Scrub
+	 * grabs inodes with DONTCACHE assuming that most inode are ok, which
+	 * is not the case here.
+	 */
+	spin_lock(&VFS_I(ip)->i_lock);
+	VFS_I(ip)->i_state &= ~I_DONTCACHE;
+	spin_unlock(&VFS_I(ip)->i_lock);
+}
+
+/* Mark inode metadata as having been checked and found unhealthy by fsck. */
+void
+xfs_inode_mark_corrupt(
+	struct xfs_inode	*ip,
+	unsigned int		mask)
+{
+	ASSERT(!(mask & ~(XFS_SICK_INO_PRIMARY | XFS_SICK_INO_ZAPPED)));
+	trace_xfs_inode_mark_corrupt(ip, mask);
+
 	spin_lock(&ip->i_flags_lock);
 	ip->i_sick |= mask;
 	ip->i_checked |= mask;

fs/xfs/xfs_trace.h

@@ -3926,9 +3926,11 @@ DEFINE_EVENT(xfs_fs_corrupt_class, name,	\
 	TP_PROTO(struct xfs_mount *mp, unsigned int flags), \
 	TP_ARGS(mp, flags))
 DEFINE_FS_CORRUPT_EVENT(xfs_fs_mark_sick);
+DEFINE_FS_CORRUPT_EVENT(xfs_fs_mark_corrupt);
 DEFINE_FS_CORRUPT_EVENT(xfs_fs_mark_healthy);
 DEFINE_FS_CORRUPT_EVENT(xfs_fs_unfixed_corruption);
 DEFINE_FS_CORRUPT_EVENT(xfs_rt_mark_sick);
+DEFINE_FS_CORRUPT_EVENT(xfs_rt_mark_corrupt);
 DEFINE_FS_CORRUPT_EVENT(xfs_rt_mark_healthy);
 DEFINE_FS_CORRUPT_EVENT(xfs_rt_unfixed_corruption);
 
@@ -3955,6 +3957,7 @@ DEFINE_EVENT(xfs_ag_corrupt_class, name,	\
 		 unsigned int flags), \
 	TP_ARGS(mp, agno, flags))
 DEFINE_AG_CORRUPT_EVENT(xfs_ag_mark_sick);
+DEFINE_AG_CORRUPT_EVENT(xfs_ag_mark_corrupt);
 DEFINE_AG_CORRUPT_EVENT(xfs_ag_mark_healthy);
 DEFINE_AG_CORRUPT_EVENT(xfs_ag_unfixed_corruption);
 
@@ -3980,6 +3983,7 @@ DEFINE_EVENT(xfs_inode_corrupt_class, name,	\
 	TP_PROTO(struct xfs_inode *ip, unsigned int flags), \
 	TP_ARGS(ip, flags))
 DEFINE_INODE_CORRUPT_EVENT(xfs_inode_mark_sick);
+DEFINE_INODE_CORRUPT_EVENT(xfs_inode_mark_corrupt);
 DEFINE_INODE_CORRUPT_EVENT(xfs_inode_mark_healthy);
 
 TRACE_EVENT(xfs_iwalk_ag,