xref: /linux-6.15/include/linux/blktrace_api.h (revision 6ed7ffdd)
1 #ifndef BLKTRACE_H
2 #define BLKTRACE_H
3 
4 #include <linux/blkdev.h>
5 #include <linux/relay.h>
6 #include <linux/compat.h>
7 #include <uapi/linux/blktrace_api.h>
8 
9 #if defined(CONFIG_BLK_DEV_IO_TRACE)
10 
11 #include <linux/sysfs.h>
12 
13 struct blk_trace {
14 	int trace_state;
15 	bool rq_based;
16 	struct rchan *rchan;
17 	unsigned long __percpu *sequence;
18 	unsigned char __percpu *msg_data;
19 	u16 act_mask;
20 	u64 start_lba;
21 	u64 end_lba;
22 	u32 pid;
23 	u32 dev;
24 	struct dentry *dir;
25 	struct dentry *dropped_file;
26 	struct dentry *msg_file;
27 	atomic_t dropped;
28 };
29 
30 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
31 extern void blk_trace_shutdown(struct request_queue *);
32 extern int do_blk_trace_setup(struct request_queue *q, char *name,
33 			      dev_t dev, struct block_device *bdev,
34 			      struct blk_user_trace_setup *buts);
35 extern __printf(2, 3)
36 void __trace_note_message(struct blk_trace *, const char *fmt, ...);
37 
38 /**
39  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
40  * @q:		queue the io is for
41  * @fmt:	format to print message in
42  * args...	Variable argument list for format
43  *
44  * Description:
45  *     Records a (simple) message onto the blktrace stream.
46  *
47  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
48  *     NOTE: Can not use 'static inline' due to presence of var args...
49  *
50  **/
51 #define blk_add_trace_msg(q, fmt, ...)					\
52 	do {								\
53 		struct blk_trace *bt = (q)->blk_trace;			\
54 		if (unlikely(bt))					\
55 			__trace_note_message(bt, fmt, ##__VA_ARGS__);	\
56 	} while (0)
57 #define BLK_TN_MAX_MSG		128
58 
59 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
60 				void *data, size_t len);
61 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
62 			   struct block_device *bdev,
63 			   char __user *arg);
64 extern int blk_trace_startstop(struct request_queue *q, int start);
65 extern int blk_trace_remove(struct request_queue *q);
66 extern void blk_trace_remove_sysfs(struct device *dev);
67 extern int blk_trace_init_sysfs(struct device *dev);
68 
69 extern struct attribute_group blk_trace_attr_group;
70 
71 #else /* !CONFIG_BLK_DEV_IO_TRACE */
72 # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
73 # define blk_trace_shutdown(q)				do { } while (0)
74 # define do_blk_trace_setup(q, name, dev, bdev, buts)	(-ENOTTY)
75 # define blk_add_driver_data(q, rq, data, len)		do {} while (0)
76 # define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
77 # define blk_trace_startstop(q, start)			(-ENOTTY)
78 # define blk_trace_remove(q)				(-ENOTTY)
79 # define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
80 # define blk_trace_remove_sysfs(dev)			do { } while (0)
81 static inline int blk_trace_init_sysfs(struct device *dev)
82 {
83 	return 0;
84 }
85 
86 #endif /* CONFIG_BLK_DEV_IO_TRACE */
87 
88 #ifdef CONFIG_COMPAT
89 
90 struct compat_blk_user_trace_setup {
91 	char name[32];
92 	u16 act_mask;
93 	u32 buf_size;
94 	u32 buf_nr;
95 	compat_u64 start_lba;
96 	compat_u64 end_lba;
97 	u32 pid;
98 };
99 #define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
100 
101 #endif
102 
103 #if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
104 
105 static inline int blk_cmd_buf_len(struct request *rq)
106 {
107 	return (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? rq->cmd_len * 3 : 1;
108 }
109 
110 extern void blk_dump_cmd(char *buf, struct request *rq);
111 extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
112 
113 #endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
114 
115 #endif
116