xfs: Add larp debug option

This patch adds a debug option to enable log attribute replay. Eventually
this can be removed when delayed attrs becomes permanent.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_attr.h

@@ -30,7 +30,11 @@ struct xfs_attr_list_context;
 
 static inline bool xfs_has_larp(struct xfs_mount *mp)
 {
+#ifdef DEBUG
+	return xfs_globals.larp;
+#else
 	return false;
+#endif
 }
 
 /*

fs/xfs/xfs_globals.c

@@ -41,5 +41,6 @@ struct xfs_globals xfs_globals = {
 #endif
 #ifdef DEBUG
 	.pwork_threads		=	-1,	/* automatic thread detection */
+	.larp			=	false,	/* log attribute replay */
 #endif
 };

fs/xfs/xfs_sysctl.h

@@ -83,6 +83,7 @@ extern xfs_param_t	xfs_params;
 struct xfs_globals {
 #ifdef DEBUG
 	int	pwork_threads;		/* parallel workqueue threads */
+	bool	larp;			/* log attribute replay */
 #endif
 	int	log_recovery_delay;	/* log recovery delay (secs) */
 	int	mount_delay;		/* mount setup delay (secs) */

fs/xfs/xfs_sysfs.c

@@ -228,6 +228,29 @@ pwork_threads_show(
 	return sysfs_emit(buf, "%d\n", xfs_globals.pwork_threads);
 }
 XFS_SYSFS_ATTR_RW(pwork_threads);
+
+static ssize_t
+larp_store(
+	struct kobject	*kobject,
+	const char	*buf,
+	size_t		count)
+{
+	ssize_t		ret;
+
+	ret = kstrtobool(buf, &xfs_globals.larp);
+	if (ret < 0)
+		return ret;
+	return count;
+}
+
+STATIC ssize_t
+larp_show(
+	struct kobject	*kobject,
+	char		*buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.larp);
+}
+XFS_SYSFS_ATTR_RW(larp);
 #endif /* DEBUG */
 
 static struct attribute *xfs_dbg_attrs[] = {
@@ -237,6 +260,7 @@ static struct attribute *xfs_dbg_attrs[] = {
 	ATTR_LIST(always_cow),
 #ifdef DEBUG
 	ATTR_LIST(pwork_threads),
+	ATTR_LIST(larp),
 #endif
 	NULL,
 };