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