ext4: split ext4_journal_start trace for debug

we might want to know why jbd2 thread using high io for detail,
split ext4_journal_start trace to ext4_journal_start_sb and
ext4_journal_start_inode, show ino and handle type when possible.
Signed-off-by: changfengnan <changfengnan@bytedance.com>
Link: https://lore.kernel.org/r/20221008120518.74870-1-changfengnan@bytedance.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4_jbd2.c

@@ -86,14 +86,20 @@ static int ext4_journal_check_start(struct super_block *sb)
 	return 0;
 }
 
-handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
+handle_t *__ext4_journal_start_sb(struct inode *inode,
+				  struct super_block *sb, unsigned int line,
 				  int type, int blocks, int rsv_blocks,
 				  int revoke_creds)
 {
 	journal_t *journal;
 	int err;
-
-	trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
+	if (inode)
+		trace_ext4_journal_start_inode(inode, blocks, rsv_blocks,
+					revoke_creds, type,
+					_RET_IP_);
+	else
+		trace_ext4_journal_start_sb(sb, blocks, rsv_blocks,
+					revoke_creds, type,
 					_RET_IP_);
 	err = ext4_journal_check_start(sb);
 	if (err < 0)

fs/ext4/ext4_jbd2.h

@@ -261,9 +261,9 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 				     (bh))
 
-handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
-				  int type, int blocks, int rsv_blocks,
-				  int revoke_creds);
+handle_t *__ext4_journal_start_sb(struct inode *inode, struct super_block *sb,
+				  unsigned int line, int type, int blocks,
+				  int rsv_blocks, int revoke_creds);
 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
 
 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
@@ -303,7 +303,7 @@ static inline int ext4_trans_default_revoke_credits(struct super_block *sb)
 }
 
 #define ext4_journal_start_sb(sb, type, nblocks)			\
-	__ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0,	\
+	__ext4_journal_start_sb(NULL, (sb), __LINE__, (type), (nblocks), 0,\
 				ext4_trans_default_revoke_credits(sb))
 
 #define ext4_journal_start(inode, type, nblocks)			\
@@ -323,7 +323,7 @@ static inline handle_t *__ext4_journal_start(struct inode *inode,
 					     int blocks, int rsv_blocks,
 					     int revoke_creds)
 {
-	return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
+	return __ext4_journal_start_sb(inode, inode->i_sb, line, type, blocks,
 				       rsv_blocks, revoke_creds);
 }
 

fs/ext4/ialloc.c

@@ -1076,8 +1076,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 
 		if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
 			BUG_ON(nblocks <= 0);
-			handle = __ext4_journal_start_sb(dir->i_sb, line_no,
-				 handle_type, nblocks, 0,
+			handle = __ext4_journal_start_sb(NULL, dir->i_sb,
+				 line_no, handle_type, nblocks, 0,
 				 ext4_trans_default_revoke_credits(sb));
 			if (IS_ERR(handle)) {
 				err = PTR_ERR(handle);

include/trace/events/ext4.h

@@ -1744,18 +1744,19 @@ TRACE_EVENT(ext4_load_inode,
 		  (unsigned long) __entry->ino)
 );
 
-TRACE_EVENT(ext4_journal_start,
+TRACE_EVENT(ext4_journal_start_sb,
 	TP_PROTO(struct super_block *sb, int blocks, int rsv_blocks,
-		 int revoke_creds, unsigned long IP),
+		 int revoke_creds, int type, unsigned long IP),
 
-	TP_ARGS(sb, blocks, rsv_blocks, revoke_creds, IP),
+	TP_ARGS(sb, blocks, rsv_blocks, revoke_creds, type, IP),
 
 	TP_STRUCT__entry(
 		__field(	dev_t,		dev		)
-		__field(unsigned long,	ip			)
+		__field(	unsigned long,	ip		)
 		__field(	int,		blocks		)
 		__field(	int,		rsv_blocks	)
 		__field(	int,		revoke_creds	)
+		__field(	int,		type		)
 	),
 
 	TP_fast_assign(
@@ -1764,11 +1765,45 @@ TRACE_EVENT(ext4_journal_start,
 		__entry->blocks		 = blocks;
 		__entry->rsv_blocks	 = rsv_blocks;
 		__entry->revoke_creds	 = revoke_creds;
+		__entry->type		 = type;
+	),
+
+	TP_printk("dev %d,%d blocks %d, rsv_blocks %d, revoke_creds %d,"
+		  " type %d, caller %pS", MAJOR(__entry->dev),
+		  MINOR(__entry->dev), __entry->blocks, __entry->rsv_blocks,
+		  __entry->revoke_creds, __entry->type, (void *)__entry->ip)
+);
+
+TRACE_EVENT(ext4_journal_start_inode,
+	TP_PROTO(struct inode *inode, int blocks, int rsv_blocks,
+		 int revoke_creds, int type, unsigned long IP),
+
+	TP_ARGS(inode, blocks, rsv_blocks, revoke_creds, type, IP),
+
+	TP_STRUCT__entry(
+		__field(	unsigned long,	ino		)
+		__field(	dev_t,		dev		)
+		__field(	unsigned long,	ip		)
+		__field(	int,		blocks		)
+		__field(	int,		rsv_blocks	)
+		__field(	int,		revoke_creds	)
+		__field(	int,		type		)
+	),
+
+	TP_fast_assign(
+		__entry->dev		 = inode->i_sb->s_dev;
+		__entry->ip		 = IP;
+		__entry->blocks		 = blocks;
+		__entry->rsv_blocks	 = rsv_blocks;
+		__entry->revoke_creds	 = revoke_creds;
+		__entry->type		 = type;
+		__entry->ino		 = inode->i_ino;
 	),
 
-	TP_printk("dev %d,%d blocks %d, rsv_blocks %d, revoke_creds %d, "
-		  "caller %pS", MAJOR(__entry->dev), MINOR(__entry->dev),
-		  __entry->blocks, __entry->rsv_blocks, __entry->revoke_creds,
+	TP_printk("dev %d,%d blocks %d, rsv_blocks %d, revoke_creds %d,"
+		  " type %d, ino %lu, caller %pS", MAJOR(__entry->dev),
+		  MINOR(__entry->dev), __entry->blocks, __entry->rsv_blocks,
+		  __entry->revoke_creds, __entry->type, __entry->ino,
 		  (void *)__entry->ip)
 );