1 files changed, 131 insertions, 0 deletions
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
new file mode 100644
index 000000000..122c62e56
--- /dev/null
+++ b/include/linux/blktrace_api.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BLKTRACE_H
+#define BLKTRACE_H
+
+#include <linux/blk-mq.h>
+#include <linux/relay.h>
+#include <linux/compat.h>
+#include <uapi/linux/blktrace_api.h>
+#include <linux/list.h>
+#include <linux/blk_types.h>
+
+#if defined(CONFIG_BLK_DEV_IO_TRACE)
+
+#include <linux/sysfs.h>
+
+struct blk_trace {
+	int trace_state;
+	struct rchan *rchan;
+	unsigned long __percpu *sequence;
+	unsigned char __percpu *msg_data;
+	u16 act_mask;
+	u64 start_lba;
+	u64 end_lba;
+	u32 pid;
+	u32 dev;
+	struct dentry *dir;
+	struct list_head running_list;
+	atomic_t dropped;
+};
+
+extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
+extern void blk_trace_shutdown(struct request_queue *);
+__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
+		struct cgroup_subsys_state *css, const char *fmt, ...);
+
+/**
+ * blk_add_trace_msg - Add a (simple) message to the blktrace stream
+ * @q:		queue the io is for
+ * @fmt:	format to print message in
+ * args...	Variable argument list for format
+ *
+ * Description:
+ *     Records a (simple) message onto the blktrace stream.
+ *
+ *     NOTE: BLK_TN_MAX_MSG characters are output at most.
+ *     NOTE: Can not use 'static inline' due to presence of var args...
+ *
+ **/
+#define blk_add_cgroup_trace_msg(q, css, fmt, ...)			\
+	do {								\
+		struct blk_trace *bt;					\
+									\
+		rcu_read_lock();					\
+		bt = rcu_dereference((q)->blk_trace);			\
+		if (unlikely(bt))					\
+			__blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
+		rcu_read_unlock();					\
+	} while (0)
+#define blk_add_trace_msg(q, fmt, ...)					\
+	blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
+#define BLK_TN_MAX_MSG		128
+
+static inline bool blk_trace_note_message_enabled(struct request_queue *q)
+{
+	struct blk_trace *bt;
+	bool ret;
+
+	rcu_read_lock();
+	bt = rcu_dereference(q->blk_trace);
+	ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
+	rcu_read_unlock();
+	return ret;
+}
+
+extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
+extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+			   struct block_device *bdev,
+			   char __user *arg);
+extern int blk_trace_startstop(struct request_queue *q, int start);
+extern int blk_trace_remove(struct request_queue *q);
+
+#else /* !CONFIG_BLK_DEV_IO_TRACE */
+# define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
+# define blk_trace_shutdown(q)				do { } while (0)
+# define blk_add_driver_data(rq, data, len)		do {} while (0)
+# define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
+# define blk_trace_startstop(q, start)			(-ENOTTY)
+# define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
+# define blk_add_cgroup_trace_msg(q, cg, fmt, ...)	do { } while (0)
+# define blk_trace_note_message_enabled(q)		(false)
+
+static inline int blk_trace_remove(struct request_queue *q)
+{
+	return -ENOTTY;
+}
+#endif /* CONFIG_BLK_DEV_IO_TRACE */
+
+#ifdef CONFIG_COMPAT
+
+struct compat_blk_user_trace_setup {
+	char name[BLKTRACE_BDEV_SIZE];
+	u16 act_mask;
+	u32 buf_size;
+	u32 buf_nr;
+	compat_u64 start_lba;
+	compat_u64 end_lba;
+	u32 pid;
+};
+#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
+
+#endif
+
+void blk_fill_rwbs(char *rwbs, blk_opf_t opf);
+
+static inline sector_t blk_rq_trace_sector(struct request *rq)
+{
+	/*
+	 * Tracing should ignore starting sector for passthrough requests and
+	 * requests where starting sector didn't get set.
+	 */
+	if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
+		return 0;
+	return blk_rq_pos(rq);
+}
+
+static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
+{
+	return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
+}
+
+#endif