btrfs: tracepoints: fix btrfs_trigger_flush symbolic string for flags (45e31869) · Commits · 戴 / test

When tracepoints use __print_symbolic to print textual representation of a value that comes from an ENUM each enum value needs to be exported to user space so that user space tools can convert the binary value data to the trings as user space does not know what those enums are about. Doing a trace-cmd record && trace-cmd report currently results in: kworker/u8:1-61 [000] 66.299527: btrfs_flush_space: 5302ee13-c65e-45bb-98ef-8fe3835bd943: state=3(0x3) flags=4(METADATA) num_bytes=2621440 ret=0 I.e state is not translated to its symbolic counterpart. With this patch applied the output is: fio-370 [002] 56.762402: btrfs_trigger_flush: d04cd7ac-38e2-452f-a7f5-8157529fd5f0: preempt: flush=3(BTRFS_RESERVE_FLUSH_ALL) flags=4(METADATA) bytes=655360 See also ("mm: tracing: Export enums in tracepoints to user space"). Signed-off-by:

Nikolay Borisov <nborisov@suse.com> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

include/trace/events/btrfs.h

+28 −6

Original line number	Diff line number	Diff line
		@@ -1042,11 +1042,33 @@ TRACE_EVENT(btrfs_space_reservation,
		__entry->bytes)
		);

		#define show_flush_action(action) \
		__print_symbolic(action, \
		{ BTRFS_RESERVE_NO_FLUSH, "BTRFS_RESERVE_NO_FLUSH"}, \
		{ BTRFS_RESERVE_FLUSH_LIMIT, "BTRFS_RESERVE_FLUSH_LIMIT"}, \
		{ BTRFS_RESERVE_FLUSH_ALL, "BTRFS_RESERVE_FLUSH_ALL"})
		#define FLUSH_ACTIONS \
		EM( BTRFS_RESERVE_NO_FLUSH, "BTRFS_RESERVE_NO_FLUSH") \
		EM( BTRFS_RESERVE_FLUSH_LIMIT, "BTRFS_RESERVE_FLUSH_LIMIT") \
		EM( BTRFS_RESERVE_FLUSH_ALL, "BTRFS_RESERVE_FLUSH_ALL") \
		EMe(BTRFS_RESERVE_FLUSH_ALL_STEAL, "BTRFS_RESERVE_FLUSH_ALL_STEAL")

		/*
		* First define the enums in the above macros to be exported to userspace via
		* TRACE_DEFINE_ENUM().
		*/

		#undef EM
		#undef EMe
		#define EM(a, b) TRACE_DEFINE_ENUM(a);
		#define EMe(a, b) TRACE_DEFINE_ENUM(a);

		FLUSH_ACTIONS

		/*
		* Now redefine the EM and EMe macros to map the enums to the strings that will
		* be printed in the output
		*/

		#undef EM
		#undef EMe
		#define EM(a, b) {a, b},
		#define EMe(a, b) {a, b}

		TRACE_EVENT(btrfs_trigger_flush,

		@@ -1071,7 +1093,7 @@ TRACE_EVENT(btrfs_trigger_flush,

		TP_printk_btrfs("%s: flush=%d(%s) flags=%llu(%s) bytes=%llu",
		__get_str(reason), __entry->flush,
		show_flush_action(__entry->flush),
		__print_symbolic(__entry->flush, FLUSH_ACTIONS),
		__entry->flags,
		__print_flags((unsigned long)__entry->flags, "\|",
		BTRFS_GROUP_FLAGS),

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