[Jfs-discussion] [PATCH 2/2] jfs: Reduce object size when CONFIG_PRINTK=n

[Joe P. <jo...@pe...>]

Allow the jfs_error format and arguments to be
optimized away when not using printk.

Reduces object size ~3KB

    $ grep -E "CONFIG_PRINTK|CONFIG_JFS" .config
    # CONFIG_PRINTK is not set
    CONFIG_JFS_FS=y
    CONFIG_JFS_POSIX_ACL=y
    CONFIG_JFS_SECURITY=y
    # CONFIG_JFS_DEBUG is not set
    CONFIG_JFS_STATISTICS=y

$ size fs/jfs/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 136521	   1408	    520	 138449	  21cd1	fs/jfs/built-in.o.new
 139834	   1408	    552	 141794	  229e2	fs/jfs/built-in.o.old

Signed-off-by: Joe Perches <jo...@pe...>
---
 fs/jfs/jfs_superblock.h | 16 +++++++++++++++-
 fs/jfs/super.c          |  4 ++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/fs/jfs/jfs_superblock.h b/fs/jfs/jfs_superblock.h
index 04847b8..85b1b31 100644
--- a/fs/jfs/jfs_superblock.h
+++ b/fs/jfs/jfs_superblock.h
@@ -108,8 +108,22 @@ struct jfs_superblock {
 
 extern int readSuper(struct super_block *, struct buffer_head **);
 extern int updateSuper(struct super_block *, uint);
+extern void jfs_handle_error(struct super_block *sb);
 __printf(2, 3)
-extern void jfs_error(struct super_block *, const char *, ...);
+extern void _jfs_error(struct super_block *, const char *, ...);
+
+#ifdef CONFIG_PRINTK
+#define jfs_error(sb, fmt, ...)			\
+	_jfs_error(sb, fmt, ##__VA_ARGS__)
+#else
+#define jfs_error(sb, fmt, ...)			\
+do {						\
+	if (0)					\
+		printk(fmt, ##__VA_ARGS__);	\
+	jfs_handle_error(sb);			\
+} while (0)
+#endif
+
 extern int jfs_mount(struct super_block *);
 extern int jfs_mount_rw(struct super_block *, int);
 extern int jfs_umount(struct super_block *);
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 6669aa2..08a826e 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -70,7 +70,7 @@ module_param(jfsloglevel, int, 0644);
 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
 #endif
 
-static void jfs_handle_error(struct super_block *sb)
+void jfs_handle_error(struct super_block *sb)
 {
 	struct jfs_sb_info *sbi = JFS_SBI(sb);
 
@@ -92,7 +92,7 @@ static void jfs_handle_error(struct super_block *sb)
 	/* nothing is done for continue beyond marking the superblock dirty */
 }
 
-void jfs_error(struct super_block *sb, const char *fmt, ...)
+void _jfs_error(struct super_block *sb, const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;
-- 
1.8.1.2.459.gbcd45b4.dirty