On Sat 23-01-21 20:00:44, Chunguang Xu wrote:

From: Chunguang Xu <redacted>

Compared to directly using numbers to indicate levels, using abstract
error, warn, notice, info, debug to indicate levels may be more
convenient for code reading and writing. Similar to other kernel
modules, some basic log interfaces are introduced.

Signed-off-by: Chunguang Xu <redacted>

One more thing I've noticed when reading this patch:

+
+#ifdef CONFIG_JBD2_DEBUG
+/*
+ * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
+ * consistency checks.  By default we don't do this unless
+ * CONFIG_JBD2_DEBUG is on.
+ */
+#define JBD2_EXPENSIVE_CHECKING
+extern ushort jbd2_journal_enable_debug;
+void jbd2_log(int level, journal_t *j, const char *file, const char *func,
+		      unsigned int line, const char *fmt, ...);
+
+#define JBD2_ERR	1	/* error conditions */
+#define JBD2_WARN	2	/* warning conditions */
+#define JBD2_NOTICE	3	/* normal but significant condition */
+#define JBD2_INFO	4	/* informational */
+#define JBD2_DEBUG	5	/* debug-level messages */

This is actually not true. All the jbd_debug() messages are really debug
messages, not errors, not warnings. It is just a different level of detail.
Honestly, these days, I'd rather discard all the levels, use pr_debug()
function to print these messages inside jdb2_debug() and defer to
CONFIG_DYNAMIC_DEBUG framework for configuration of which messages are
interesting for a particular debug session.

								Honza

+
+#define jbd2_err(j, fmt, a...)						\
+	jbd2_log(JBD2_ERR, j, __FILE__, __func__, __LINE__, (fmt), ##a)
+
+#define jbd2_warn(j, fmt, a...)						\
+	jbd2_log(JBD2_WARN, j, __FILE__, __func__, __LINE__, (fmt), ##a)
+
+#define jbd2_notice(j, fmt, a...)					\
+	jbd2_log(JBD2_NOTICE, j, __FILE__, __func__, __LINE__, (fmt), ##a)
+
+#define jbd2_info(j, fmt, a...)						\
+	jbd2_log(JBD2_INFO, j, __FILE__, __func__, __LINE__, (fmt), ##a)
+
+#define jbd2_debug(j, fmt, a...)					\
+	jbd2_log(JBD2_DEBUG, j, __FILE__, __func__, __LINE__, (fmt), ##a)
+
+#else
+
+#define jbd2_err(j, fmt, a...)
+#define jbd2_warn(j, fmt, a...)
+#define jbd2_notice(j, fmt, a...)
+#define jbd2_info(j, fmt, a...)
+#define jbd2_debug(j, fmt, a...)
+
+#endif
 #endif
 
 /*
-- 
2.30.0

-- 
Jan Kara [off-list ref]
SUSE Labs, CR