[PATCH v7 08/14] ceph: add boutc wrappers for BLOG

[Alex Markuze <amarkuze@redhat.com>]

Add boutc()/boutc_bounded()/boutc_formats() macros to ceph_debug.h as
drop-in replacements for doutc().  When BLOG is enabled they serialize
to binary; when disabled they fall back to doutc().

Resolve the optional binary context before choosing the backend.
Expand the doutc fallback only once per call site to avoid duplicate
dynamic-debug metadata and excessive VFS stack frames.

Signed-off-by: Alex Markuze <amarkuze@redhat.com>
Assisted-by: LLM
---
 include/linux/ceph/ceph_debug.h | 81 ++++++++++++++++++++++++++++-----
 1 file changed, 69 insertions(+), 12 deletions(-)

diff --git a/include/linux/ceph/ceph_debug.h b/include/linux/ceph/ceph_debug.h
index 5f904591fa5f..e055091d5c3c 100644
--- a/include/linux/ceph/ceph_debug.h
+++ b/include/linux/ceph/ceph_debug.h
@@ -5,28 +5,22 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/string.h>
+#include <linux/jump_label.h>
 
 #ifdef CONFIG_CEPH_LIB_PRETTYDEBUG
 
-/*
- * wrap pr_debug to include a filename:lineno prefix on each line.
- * this incurs some overhead (kernel size and execution time) due to
- * the extra function call at each call site.
- */
-
 # if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 #  define dout(fmt, ...)						\
 	pr_debug("%.*s %12.12s:%-4d : " fmt,				\
 		 8 - (int)sizeof(KBUILD_MODNAME), "    ",		\
 		 kbasename(__FILE__), __LINE__, ##__VA_ARGS__)
 #  define doutc(client, fmt, ...)					\
-	pr_debug("%.*s %12.12s:%-4d : [%pU %llu] " fmt,			\
+	pr_debug("%.*s %12.12s:%-4d : [%pU %llu] " fmt,		\
 		 8 - (int)sizeof(KBUILD_MODNAME), "    ",		\
 		 kbasename(__FILE__), __LINE__,				\
 		 &client->fsid, client->monc.auth->global_id,		\
 		 ##__VA_ARGS__)
 # else
-/* faux printk call just to see any compiler warnings. */
 #  define dout(fmt, ...)					\
 		no_printk(KERN_DEBUG fmt, ##__VA_ARGS__)
 #  define doutc(client, fmt, ...)				\
@@ -38,16 +32,79 @@
 
 #else
 
-/*
- * or, just wrap pr_debug
- */
 # define dout(fmt, ...)	pr_debug(" " fmt, ##__VA_ARGS__)
 # define doutc(client, fmt, ...)					\
-	pr_debug(" [%pU %llu] %s: " fmt, &client->fsid,			\
+	pr_debug(" [%pU %llu] %s: " fmt, &client->fsid,		\
 		 client->monc.auth->global_id, __func__, ##__VA_ARGS__)
 
 #endif
 
+/*
+ * boutc* -- binary-logging variants of doutc*.
+ *
+ * When Ceph BLOG tracing has been explicitly enabled and a BLOG context
+ * has been bound for the current task (via ceph_blog_enter()),
+ * these route through the BLOG serialization path. Otherwise they fall
+ * back to the traditional text-based doutc macros so that existing
+ * debug semantics remain unchanged.
+ *
+ * Must only be used from fs/ceph/ where client->private is a
+ * ceph_fs_client *.  Do not call from net/ceph or RBD; ->private is not
+ * an fsc there (ceph_blog_key stays false, but the cast is still wrong).
+ */
+#define __ceph_blog_args(...) __VA_ARGS__
+#if IS_ENABLED(CONFIG_CEPH_FS) && IS_ENABLED(CONFIG_DEBUG_FS)
+# include <linux/ceph/ceph_blog.h>
+# define boutc(client, fmt, ...) \
+	do { \
+		struct blog_tls_ctx *__ctx = NULL; \
+		if (static_branch_unlikely(&ceph_blog_key)) \
+			__ctx = ceph_blog_get_cached_ctx( \
+				(struct ceph_fs_client *)(client)->private); \
+		if (__ctx) \
+			CEPH_BLOG_LOG_CLIENT(__ctx, client, fmt, ##__VA_ARGS__); \
+		else \
+			doutc(client, fmt, ##__VA_ARGS__); \
+	} while (0)
+# define boutc_bounded(client, fmt, blog_args, text_args) \
+	do { \
+		struct blog_tls_ctx *__ctx = NULL; \
+		if (static_branch_unlikely(&ceph_blog_key)) \
+			__ctx = ceph_blog_get_cached_ctx( \
+				(struct ceph_fs_client *)(client)->private); \
+		if (__ctx) \
+			CEPH_BLOG_LOG_CLIENT(__ctx, client, fmt, \
+					     __ceph_blog_args blog_args); \
+		else \
+			doutc(client, fmt, __ceph_blog_args text_args); \
+	} while (0)
+# define boutc_formats(client, blog_fmt, text_fmt, blog_args, text_args) \
+	do { \
+		struct blog_tls_ctx *__ctx = NULL; \
+		if (static_branch_unlikely(&ceph_blog_key)) \
+			__ctx = ceph_blog_get_cached_ctx( \
+				(struct ceph_fs_client *)(client)->private); \
+		if (__ctx) \
+			CEPH_BLOG_LOG_CLIENT(__ctx, client, blog_fmt, \
+					     __ceph_blog_args blog_args); \
+		else \
+			doutc(client, text_fmt, __ceph_blog_args text_args); \
+	} while (0)
+#else
+# define boutc(client, fmt, ...) doutc(client, fmt, ##__VA_ARGS__)
+# define boutc_bounded(client, fmt, blog_args, text_args) \
+	do { \
+		(void)sizeof(#blog_args); \
+		doutc(client, fmt, __ceph_blog_args text_args); \
+	} while (0)
+# define boutc_formats(client, blog_fmt, text_fmt, blog_args, text_args) \
+	do { \
+		(void)sizeof(blog_fmt); \
+		(void)sizeof(#blog_args); \
+		doutc(client, text_fmt, __ceph_blog_args text_args); \
+	} while (0)
+#endif
+
 #define pr_notice_client(client, fmt, ...)				\
 	pr_notice("[%pU %llu]: " fmt, &client->fsid,			\
 		  client->monc.auth->global_id, ##__VA_ARGS__)
-- 
2.34.1