xref: /linux-6.15/include/linux/blktrace_api.h (revision 9d64fc08)
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 #include <linux/list.h>
9 
10 #if defined(CONFIG_BLK_DEV_IO_TRACE)
11 
12 #include <linux/sysfs.h>
13 
14 struct blk_trace {
15 	int trace_state;
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 	struct list_head running_list;
28 	atomic_t dropped;
29 };
30 
31 struct blkcg;
32 
33 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
34 extern void blk_trace_shutdown(struct request_queue *);
35 extern __printf(3, 4)
36 void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, 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_cgroup_trace_msg(q, cg, fmt, ...)			\
52 	do {								\
53 		struct blk_trace *bt = (q)->blk_trace;			\
54 		if (unlikely(bt))					\
55 			__trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\
56 	} while (0)
57 #define blk_add_trace_msg(q, fmt, ...)					\
58 	blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
59 #define BLK_TN_MAX_MSG		128
60 
61 static inline bool blk_trace_note_message_enabled(struct request_queue *q)
62 {
63 	struct blk_trace *bt = q->blk_trace;
64 	if (likely(!bt))
65 		return false;
66 	return bt->act_mask & BLK_TC_NOTIFY;
67 }
68 
69 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
70 				void *data, size_t len);
71 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
72 			   struct block_device *bdev,
73 			   char __user *arg);
74 extern int blk_trace_startstop(struct request_queue *q, int start);
75 extern int blk_trace_remove(struct request_queue *q);
76 extern void blk_trace_remove_sysfs(struct device *dev);
77 extern int blk_trace_init_sysfs(struct device *dev);
78 
79 extern struct attribute_group blk_trace_attr_group;
80 
81 #else /* !CONFIG_BLK_DEV_IO_TRACE */
82 # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
83 # define blk_trace_shutdown(q)				do { } while (0)
84 # define blk_add_driver_data(q, rq, data, len)		do {} while (0)
85 # define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
86 # define blk_trace_startstop(q, start)			(-ENOTTY)
87 # define blk_trace_remove(q)				(-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_remove_sysfs(dev)			do { } while (0)
91 # define blk_trace_note_message_enabled(q)		(false)
92 static inline int blk_trace_init_sysfs(struct device *dev)
93 {
94 	return 0;
95 }
96 
97 #endif /* CONFIG_BLK_DEV_IO_TRACE */
98 
99 #ifdef CONFIG_COMPAT
100 
101 struct 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 
114 extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
115 
116 static inline sector_t blk_rq_trace_sector(struct request *rq)
117 {
118 	return blk_rq_is_passthrough(rq) ? 0 : blk_rq_pos(rq);
119 }
120 
121 static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
122 {
123 	return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
124 }
125 
126 #endif
127