blktrace_api.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef BLKTRACE_H
  3#define BLKTRACE_H
  4
  5#include <linux/blk-mq.h>
  6#include <linux/relay.h>
  7#include <linux/compat.h>
  8#include <uapi/linux/blktrace_api.h>
  9#include <linux/list.h>
 10#include <linux/blk_types.h>
 11
 12#if defined(CONFIG_BLK_DEV_IO_TRACE)
 13
 14#include <linux/sysfs.h>
 15
 16struct blk_trace {
 17	int version;
 18	int trace_state;
 19	struct rchan *rchan;
 20	unsigned long __percpu *sequence;
 21	unsigned char __percpu *msg_data;
 22	u64 act_mask;
 23	u64 start_lba;
 24	u64 end_lba;
 25	u32 pid;
 26	u32 dev;
 27	struct dentry *dir;
 28	struct list_head running_list;
 29	atomic_t dropped;
 30};
 31
 32extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 33extern void blk_trace_shutdown(struct request_queue *);
 34__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
 35		struct cgroup_subsys_state *css, const char *fmt, ...);
 36
 37/**
 38 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
 39 * @q:		queue the io is for
 40 * @fmt:	format to print message in
 41 * args...	Variable argument list for format
 42 *
 43 * Description:
 44 *     Records a (simple) message onto the blktrace stream.
 45 *
 46 *     NOTE: BLK_TN_MAX_MSG characters are output at most.
 47 *     NOTE: Can not use 'static inline' due to presence of var args...
 48 *
 49 **/
 50#define blk_add_cgroup_trace_msg(q, css, fmt, ...)			\
 51	do {								\
 52		struct blk_trace *bt;					\
 53									\
 54		rcu_read_lock();					\
 55		bt = rcu_dereference((q)->blk_trace);			\
 56		if (unlikely(bt))					\
 57			__blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
 58		rcu_read_unlock();					\
 59	} while (0)
 60#define blk_add_trace_msg(q, fmt, ...)					\
 61	blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
 62#define BLK_TN_MAX_MSG		128
 63
 64static inline bool blk_trace_note_message_enabled(struct request_queue *q)
 65{
 66	struct blk_trace *bt;
 67	bool ret;
 68
 69	rcu_read_lock();
 70	bt = rcu_dereference(q->blk_trace);
 71	ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
 72	rcu_read_unlock();
 73	return ret;
 74}
 75
 76extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
 77extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 78			   struct block_device *bdev,
 79			   char __user *arg);
 80extern int blk_trace_startstop(struct request_queue *q, int start);
 81extern int blk_trace_remove(struct request_queue *q);
 82
 83#else /* !CONFIG_BLK_DEV_IO_TRACE */
 84# define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
 85# define blk_trace_shutdown(q)				do { } while (0)
 86# define blk_add_driver_data(rq, data, len)		do {} while (0)
 87# define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
 88# define blk_trace_startstop(q, start)			(-ENOTTY)
 89# define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
 90# define blk_add_cgroup_trace_msg(q, cg, fmt, ...)	do { } while (0)
 91# define blk_trace_note_message_enabled(q)		(false)
 92
 93static inline int blk_trace_remove(struct request_queue *q)
 94{
 95	return -ENOTTY;
 96}
 97#endif /* CONFIG_BLK_DEV_IO_TRACE */
 98
 99#ifdef CONFIG_COMPAT
100
101struct compat_blk_user_trace_setup {
102	char name[BLKTRACE_BDEV_SIZE];
103	u16 act_mask;
104	u32 buf_size;
105	u32 buf_nr;
106	compat_u64 start_lba;
107	compat_u64 end_lba;
108	u32 pid;
109};
110#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
111
112#endif
113
114void blk_fill_rwbs(char *rwbs, blk_opf_t opf);
115
116static inline sector_t blk_rq_trace_sector(struct request *rq)
117{
118	/*
119	 * Tracing should ignore starting sector for passthrough requests and
120	 * requests where starting sector didn't get set.
121	 */
122	if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
123		return 0;
124	return blk_rq_pos(rq);
125}
126
127static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
128{
129	return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
130}
131
132#endif