linux/include/linux/blktrace_api.h

/* 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 { … };

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, ...) …
#define blk_add_trace_msg(q, fmt, ...) …
#define BLK_TN_MAX_MSG …

static inline bool blk_trace_note_message_enabled(struct request_queue *q)
{ … }

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 …
#define blk_trace_shutdown …
#define blk_add_driver_data …
#define blk_trace_setup …
#define blk_trace_startstop …
#define blk_add_trace_msg …
#define blk_add_cgroup_trace_msg …
#define blk_trace_note_message_enabled …

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 { … };
#define BLKTRACESETUP32 …

#endif

void blk_fill_rwbs(char *rwbs, blk_opf_t opf);

static inline sector_t blk_rq_trace_sector(struct request *rq)
{ … }

static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
{ … }

#endif