[PATCH v3 2/2] Add XFS messages to printk index

[Jonathan Lassoff <jof@xxxxxxxxxx>]

In order for end users to quickly react to new issues that come up in
production, it is proving useful to leverage the printk indexing system.
This printk index enables kernel developers to use calls to printk()
with changeable ad-hoc format strings, while still enabling end users
to detect changes from release to release.

So that detailed XFS messages are captures by this printk index, this
patch wraps the xfs_<level> and xfs_alert_tag functions.

Signed-off-by: Jonathan Lassoff <jof@xxxxxxxxxx>
---

Notes:
    [PATCH v1]
      * De-duplicate kernel logging levels and tidy whitespace.
    [PATCH v2]
      * Split changes into two patches:
         - function and prototype de-duplication.
         - Adding printk indexing
    [PATCH v3]
      * Fix some whitespace and semicolon. *facepalm*

 fs/xfs/xfs_message.c |  2 +-
 fs/xfs/xfs_message.h | 29 ++++++++++++++++++++---------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/xfs_message.c b/fs/xfs/xfs_message.c
index ede8a4f2f676..f01efad20420 100644
--- a/fs/xfs/xfs_message.c
+++ b/fs/xfs/xfs_message.c
@@ -51,7 +51,7 @@ void xfs_printk_level(
 }
 
 void
-xfs_alert_tag(
+_xfs_alert_tag(
 	const struct xfs_mount	*mp,
 	int			panic_tag,
 	const char		*fmt, ...)
diff --git a/fs/xfs/xfs_message.h b/fs/xfs/xfs_message.h
index 2f609800e806..6f9a1b67c4d7 100644
--- a/fs/xfs/xfs_message.h
+++ b/fs/xfs/xfs_message.h
@@ -6,34 +6,45 @@
 
 struct xfs_mount;
 
+#define xfs_printk_index_wrap(kern_level, mp, fmt, ...)		\
+({								\
+	printk_index_subsys_emit("%sXFS%s: ", kern_level, fmt);	\
+	xfs_printk_level(kern_level, mp, fmt, ##__VA_ARGS__);	\
+})
 extern __printf(3, 4)
 void xfs_printk_level(
 	const char *kern_level,
 	const struct xfs_mount *mp,
 	const char *fmt, ...);
 #define xfs_emerg(mp, fmt, ...) \
-	xfs_printk_level(KERN_EMERG, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_EMERG, mp, fmt, ##__VA_ARGS__)
 #define xfs_alert(mp, fmt, ...) \
-	xfs_printk_level(KERN_ALERT, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_ALERT, mp, fmt, ##__VA_ARGS__)
 #define xfs_crit(mp, fmt, ...) \
-	xfs_printk_level(KERN_CRIT, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_CRIT, mp, fmt, ##__VA_ARGS__)
 #define xfs_err(mp, fmt, ...) \
-	xfs_printk_level(KERN_ERR, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_ERR, mp, fmt, ##__VA_ARGS__)
 #define xfs_warn(mp, fmt, ...) \
-	xfs_printk_level(KERN_WARNING, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_WARNING, mp, fmt, ##__VA_ARGS__)
 #define xfs_notice(mp, fmt, ...) \
-	xfs_printk_level(KERN_NOTICE, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_NOTICE, mp, fmt, ##__VA_ARGS__)
 #define xfs_info(mp, fmt, ...) \
-	xfs_printk_level(KERN_INFO, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_INFO, mp, fmt, ##__VA_ARGS__)
 #ifdef DEBUG
 #define xfs_debug(mp, fmt, ...) \
-	xfs_printk_level(KERN_DEBUG, mp, fmt, ##__VA_ARGS__)
+	xfs_printk_index_wrap(KERN_DEBUG, mp, fmt, ##__VA_ARGS__)
 #else
 #define xfs_debug(mp, fmt, ...) do {} while (0)
 #endif
 
+#define xfs_alert_tag(mp, tag, fmt, ...)			\
+({								\
+	printk_index_subsys_emit("%sXFS%s: ", KERN_ALERT, fmt);	\
+	_xfs_alert_tag(mp, tag, fmt, ##__VA_ARGS__);		\
+})
+
 extern __printf(3, 4)
-void xfs_alert_tag(const struct xfs_mount *mp, int tag, const char *fmt, ...);
+void _xfs_alert_tag(const struct xfs_mount *mp, int tag, const char *fmt, ...);
 
 
 #define xfs_printk_ratelimited(func, dev, fmt, ...)			\
-- 
2.35.1