Re: [PATCH -next] jbd2: use the correct print format

From: Jason Yan
Date: Mon Oct 10 2022 - 10:35:50 EST


Hi Bixuan,

On 2022/10/10 16:09, Bixuan Cui wrote:
The print format error was found when using ftrace event:
<...>-1406 [000] .... 23599442.895823: jbd2_end_commit: dev 252,8 transaction -1866216965 sync 0 head -1866217368
<...>-1406 [000] .... 23599442.896299: jbd2_start_commit: dev 252,8 transaction -1866216964 sync 0

Print transaction and head with the unsigned format "%u" instead.

Fixes: 879c5e6b7cb4 ('jbd2: convert instrumentation from markers to tracepoints')
Signed-off-by: Bixuan Cui <cuibixuan@xxxxxxxxxxxxxxxxx>
---
include/trace/events/jbd2.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h
index 99f783c..ce9accb 100644
--- a/include/trace/events/jbd2.h
+++ b/include/trace/events/jbd2.h
@@ -40,7 +40,7 @@
TP_STRUCT__entry(
__field( dev_t, dev )
__field( char, sync_commit )
- __field( int, transaction )
+ __field( tid_t, transaction )

While you are at it, can you make all the tid tracing consistent. Some tracing points using unsigned long such as:

TRACE_EVENT(jbd2_handle_extend,
TP_PROTO(dev_t dev, unsigned long tid, unsigned int type,
unsigned int line_no, int buffer_credits,
int requested_blocks),

TP_ARGS(dev, tid, type, line_no, buffer_credits, requested_blocks),


and the caller passing transaction->t_tid which is tid_t(unsigned int).

trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev,
transaction->t_tid,
handle->h_type, handle->h_line_no,
handle->h_total_credits,
nblocks);

Thanks,
Jason

),
TP_fast_assign(
@@ -49,7 +49,7 @@
__entry->transaction = commit_transaction->t_tid;
),
- TP_printk("dev %d,%d transaction %d sync %d",
+ TP_printk("dev %d,%d transaction %u sync %d",




MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->transaction, __entry->sync_commit)
);
@@ -97,8 +97,8 @@
TP_STRUCT__entry(
__field( dev_t, dev )
__field( char, sync_commit )
- __field( int, transaction )
- __field( int, head )
+ __field( tid_t, transaction )
+ __field( tid_t, head )
),
TP_fast_assign(
@@ -108,7 +108,7 @@
__entry->head = journal->j_tail_sequence;
),
- TP_printk("dev %d,%d transaction %d sync %d head %d",
+ TP_printk("dev %d,%d transaction %u sync %d head %u",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->transaction, __entry->sync_commit, __entry->head)
);