xfs: add trace point for fs shutdown

Add a tracepoint for fs shutdowns so we can capture that in ftrace
output.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_error.h

@@ -75,4 +75,16 @@ extern int xfs_errortag_clearall(struct xfs_mount *mp);
 #define		XFS_PTAG_FSBLOCK_ZERO		0x00000080
 #define		XFS_PTAG_VERIFIER_ERROR		0x00000100
 
+#define XFS_PTAG_STRINGS \
+	{ XFS_NO_PTAG,			"none" }, \
+	{ XFS_PTAG_IFLUSH,		"iflush" }, \
+	{ XFS_PTAG_LOGRES,		"logres" }, \
+	{ XFS_PTAG_AILDELETE,		"aildelete" }, \
+	{ XFS_PTAG_ERROR_REPORT	,	"error_report" }, \
+	{ XFS_PTAG_SHUTDOWN_CORRUPT,	"corrupt" }, \
+	{ XFS_PTAG_SHUTDOWN_IOERROR,	"ioerror" }, \
+	{ XFS_PTAG_SHUTDOWN_LOGERROR,	"logerror" }, \
+	{ XFS_PTAG_FSBLOCK_ZERO,	"fsb_zero" }, \
+	{ XFS_PTAG_VERIFIER_ERROR,	"verifier" }
+
 #endif	/* __XFS_ERROR_H__ */

fs/xfs/xfs_fsops.c

@@ -19,6 +19,7 @@
 #include "xfs_log.h"
 #include "xfs_ag.h"
 #include "xfs_ag_resv.h"
+#include "xfs_trace.h"
 
 /*
  * Write new AG headers to disk. Non-transactional, but need to be
@@ -551,6 +552,8 @@ xfs_do_force_shutdown(
 		why = "Metadata I/O Error";
 	}
 
+	trace_xfs_force_shutdown(mp, tag, flags, fname, lnnum);
+
 	xfs_alert_tag(mp, tag,
 "%s (0x%x) detected at %pS (%s:%d).  Shutting down filesystem.",
 			why, flags, __return_address, fname, lnnum);

fs/xfs/xfs_mount.h

@@ -331,6 +331,12 @@ void xfs_do_force_shutdown(struct xfs_mount *mp, int flags, char *fname,
 #define SHUTDOWN_FORCE_UMOUNT	0x0004	/* shutdown from a forced unmount */
 #define SHUTDOWN_CORRUPT_INCORE	0x0008	/* corrupt in-memory data structures */
 
+#define XFS_SHUTDOWN_STRINGS \
+	{ SHUTDOWN_META_IO_ERROR,	"metadata_io" }, \
+	{ SHUTDOWN_LOG_IO_ERROR,	"log_io" }, \
+	{ SHUTDOWN_FORCE_UMOUNT,	"force_umount" }, \
+	{ SHUTDOWN_CORRUPT_INCORE,	"corruption" }
+
 /*
  * Flags for xfs_mountfs
  */

fs/xfs/xfs_trace.c

@@ -33,6 +33,7 @@
 #include "xfs_icache.h"
 #include "xfs_ag.h"
 #include "xfs_ag_resv.h"
+#include "xfs_error.h"
 
 /*
  * We include this last to have the helpers above available for the trace

fs/xfs/xfs_trace.h

@@ -4096,6 +4096,33 @@ DEFINE_DAS_STATE_EVENT(xfs_attr_set_iter_return);
 DEFINE_DAS_STATE_EVENT(xfs_attr_node_addname_return);
 DEFINE_DAS_STATE_EVENT(xfs_attr_remove_iter_return);
 DEFINE_DAS_STATE_EVENT(xfs_attr_rmtval_remove_return);
+
+TRACE_EVENT(xfs_force_shutdown,
+	TP_PROTO(struct xfs_mount *mp, int ptag, int flags, const char *fname,
+		 int line_num),
+	TP_ARGS(mp, ptag, flags, fname, line_num),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(int, ptag)
+		__field(int, flags)
+		__string(fname, fname)
+		__field(int, line_num)
+	),
+	TP_fast_assign(
+		__entry->dev = mp->m_super->s_dev;
+		__entry->ptag = ptag;
+		__entry->flags = flags;
+		__assign_str(fname, fname);
+		__entry->line_num = line_num;
+	),
+	TP_printk("dev %d:%d tag %s flags %s file %s line_num %d",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		__print_flags(__entry->ptag, "|", XFS_PTAG_STRINGS),
+		__print_flags(__entry->flags, "|", XFS_SHUTDOWN_STRINGS),
+		__get_str(fname),
+		__entry->line_num)
+);
+
 #endif /* _TRACE_XFS_H */
 
 #undef TRACE_INCLUDE_PATH