From: Nikolay Borisov <nborisov@suse.com>
Date: Fri, 19 Jun 2020 15:24:46 +0300
Subject: btrfs: tracepoints: fix btrfs_trigger_flush symbolic string for flags
Git-commit: 45e31869cc4fa8d7c7d2b890965b1b3abf0cfd6d
Patch-mainline: v5.9-rc1
References: bsc#1135481
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 190f0b76ca49 ("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 | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 360b0f9d2220..4ccd81fae385 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -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),