[PATCHv3 02/10] ext4: Fix ext4_fc_stats trace point

Ritesh Harjani
2022-03-12T05:41:30Z

ftrace's __print_symbolic() requires that any enum values used in the
symbol to string translation table be wrapped in a TRACE_DEFINE_ENUM
so that the enum value can be decoded from the ftrace ring buffer by
user space tooling.

This patch also fixes few other problems found in this trace point.
e.g. dereferencing structures in TP_printk which should not be done
at any cost.

Also to avoid checkpatch warnings, this patch removes those
whitespaces/tab stops issues.

Cc: stable@kernel.org
Fixes: commit aa75f4d3daae ("ext4: main fast-commit commit path")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
include/trace/events/ext4.h | 78 +++++++++++++++++++++++--------------
1 file changed, 49 insertions(+), 29 deletions(-)

diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 19e957b7f941..1a0b7030f72a 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -95,6 +95,17 @@ TRACE_DEFINE_ENUM(ES_REFERENCED_B);
{ FALLOC_FL_COLLAPSE_RANGE, "COLLAPSE_RANGE"}, \
{ FALLOC_FL_ZERO_RANGE, "ZERO_RANGE"})

+TRACE_DEFINE_ENUM(EXT4_FC_REASON_XATTR);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_CROSS_RENAME);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_JOURNAL_FLAG_CHANGE);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_NOMEM);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_SWAP_BOOT);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_RESIZE);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_RENAME_DIR);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_FALLOC_RANGE);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_INODE_JOURNAL_DATA);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_MAX);
+
#define show_fc_reason(reason) \
__print_symbolic(reason, \
{ EXT4_FC_REASON_XATTR, "XATTR"}, \
@@ -2723,41 +2734,50 @@ TRACE_EVENT(ext4_fc_commit_stop,

#define FC_REASON_NAME_STAT(reason) \
show_fc_reason(reason), \
- __entry->sbi->s_fc_stats.fc_ineligible_reason_count[reason]
+ __entry->fc_ineligible_rc[reason]

TRACE_EVENT(ext4_fc_stats,
- TP_PROTO(struct super_block *sb),
-
- TP_ARGS(sb),
+ TP_PROTO(struct super_block *sb),

- TP_STRUCT__entry(
- __field(dev_t, dev)
- __field(struct ext4_sb_info *, sbi)
- __field(int, count)
- ),
+ TP_ARGS(sb),

- TP_fast_assign(
- __entry->dev = sb->s_dev;
- __entry->sbi = EXT4_SB(sb);
- ),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __array(unsigned int, fc_ineligible_rc, EXT4_FC_REASON_MAX)
+ __field(unsigned long, fc_commits)
+ __field(unsigned long, fc_ineligible_commits)
+ __field(unsigned long, fc_numblks)
+ ),

- TP_printk("dev %d:%d fc ineligible reasons:\n"
- "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d; "
- "num_commits:%ld, ineligible: %ld, numblks: %ld",
- MAJOR(__entry->dev), MINOR(__entry->dev),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_CROSS_RENAME),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_JOURNAL_FLAG_CHANGE),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_NOMEM),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_SWAP_BOOT),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_RESIZE),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_RENAME_DIR),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_FALLOC_RANGE),
- FC_REASON_NAME_STAT(EXT4_FC_REASON_INODE_JOURNAL_DATA),
- __entry->sbi->s_fc_stats.fc_num_commits,
- __entry->sbi->s_fc_stats.fc_ineligible_commits,
- __entry->sbi->s_fc_stats.fc_numblks)
+ TP_fast_assign(
+ int i;

+ __entry->dev = sb->s_dev;
+ for (i = 0; i < EXT4_FC_REASON_MAX; i++) {
+ __entry->fc_ineligible_rc[i] =
+ EXT4_SB(sb)->s_fc_stats.fc_ineligible_reason_count[i];
+ }
+ __entry->fc_commits = EXT4_SB(sb)->s_fc_stats.fc_num_commits;
+ __entry->fc_ineligible_commits =
+ EXT4_SB(sb)->s_fc_stats.fc_ineligible_commits;
+ __entry->fc_numblks = EXT4_SB(sb)->s_fc_stats.fc_numblks;
+ ),
+
+ TP_printk("dev %d,%d fc ineligible reasons:\n"
+ "%s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u "
+ "num_commits:%lu, ineligible: %lu, numblks: %lu",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_CROSS_RENAME),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_JOURNAL_FLAG_CHANGE),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_NOMEM),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_SWAP_BOOT),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_RESIZE),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_RENAME_DIR),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_FALLOC_RANGE),
+ FC_REASON_NAME_STAT(EXT4_FC_REASON_INODE_JOURNAL_DATA),
+ __entry->fc_commits, __entry->fc_ineligible_commits,
+ __entry->fc_numblks)
);

#define DEFINE_TRACE_DENTRY_EVENT(__type) \
--
2.31.1