ocfs2: Compile-time disabling of ocfs2 debugging output.

Give gcc the chance to compile out the debug logging code in ocfs2.
This saves some size at the expense of being able to debug the code.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/Kconfig

@@ -356,6 +356,16 @@ config OCFS2_FS
 	          - POSIX ACLs
 	          - readpages / writepages (not user visible)
 
+config OCFS2_DEBUG_MASKLOG
+	bool "OCFS2 logging support"
+	depends on OCFS2_FS
+	default y
+	help
+	  The ocfs2 filesystem has an extensive logging system.  The system
+	  allows selection of events to log via files in /sys/o2cb/logmask/.
+	  This option will enlarge your kernel, but it allows debugging of
+	  ocfs2 filesystem issues.
+
 config MINIX_FS
 	tristate "Minix fs support"
 	help

fs/ocfs2/cluster/masklog.h

@@ -123,6 +123,17 @@
 #define MLOG_MASK_PREFIX 0
 #endif
 
+/*
+ * When logging is disabled, force the bit test to 0 for anything other
+ * than errors and notices, allowing gcc to remove the code completely.
+ * When enabled, allow all masks.
+ */
+#if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
+#define ML_ALLOWED_BITS ~0
+#else
+#define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
+#endif
+
 #define MLOG_MAX_BITS 64
 
 struct mlog_bits {
@@ -187,7 +198,8 @@ extern struct mlog_bits mlog_and_bits, mlog_not_bits;
 
 #define mlog(mask, fmt, args...) do {					\
 	u64 __m = MLOG_MASK_PREFIX | (mask);				\
-	if (__mlog_test_u64(__m, mlog_and_bits) &&			\
+	if ((__m & ML_ALLOWED_BITS) &&					\
+	    __mlog_test_u64(__m, mlog_and_bits) &&			\
 	    !__mlog_test_u64(__m, mlog_not_bits)) {			\
 		if (__m & ML_ERROR)					\
 			__mlog_printk(KERN_ERR, "ERROR: "fmt , ##args);	\
@@ -204,6 +216,7 @@ extern struct mlog_bits mlog_and_bits, mlog_not_bits;
 		mlog(ML_ERROR, "status = %lld\n", (long long)_st);	\
 } while (0)
 
+#if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
 #define mlog_entry(fmt, args...) do {					\
 	mlog(ML_ENTRY, "ENTRY:" fmt , ##args);				\
 } while (0)
@@ -247,6 +260,13 @@ extern struct mlog_bits mlog_and_bits, mlog_not_bits;
 #define mlog_exit_void() do {						\
 	mlog(ML_EXIT, "EXIT\n");					\
 } while (0)
+#else
+#define mlog_entry(...)  do { } while (0)
+#define mlog_entry_void(...)  do { } while (0)
+#define mlog_exit(...)  do { } while (0)
+#define mlog_exit_ptr(...)  do { } while (0)
+#define mlog_exit_void(...)  do { } while (0)
+#endif  /* defined(CONFIG_OCFS2_DEBUG_MASKLOG) */
 
 #define mlog_bug_on_msg(cond, fmt, args...) do {			\
 	if (cond) {							\

fs/ocfs2/dir.c

@@ -213,11 +213,9 @@ int ocfs2_find_files_on_disk(const char *name,
 			     struct ocfs2_dir_entry **dirent)
 {
 	int status = -ENOENT;
-	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
-	mlog_entry("(osb=%p, parent=%llu, name='%.*s', blkno=%p, inode=%p)\n",
-		   osb, (unsigned long long)OCFS2_I(inode)->ip_blkno,
-		   namelen, name, blkno, inode);
+	mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n",
+		   namelen, name, blkno, inode, dirent_bh, dirent);
 
 	*dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent);
 	if (!*dirent_bh || !*dirent) {

fs/ocfs2/mmap.c

@@ -46,12 +46,12 @@ static struct page *ocfs2_nopage(struct vm_area_struct * area,
 				 unsigned long address,
 				 int *type)
 {
-	struct inode *inode = area->vm_file->f_dentry->d_inode;
 	struct page *page = NOPAGE_SIGBUS;
 	sigset_t blocked, oldset;
 	int ret;
 
-	mlog_entry("(inode %lu, address %lu)\n", inode->i_ino, address);
+	mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
+		   type);
 
 	/* The best way to deal with signals in this path is
 	 * to block them upfront, rather than allowing the