xref: /linux-6.15/include/linux/blktrace_api.h (revision 2e4c77be)
1 #ifndef BLKTRACE_H
2 #define BLKTRACE_H
3 
4 #ifdef __KERNEL__
5 #include <linux/blkdev.h>
6 #include <linux/relay.h>
7 #endif
8 
9 /*
10  * Trace categories
11  */
12 enum blktrace_cat {
13 	BLK_TC_READ	= 1 << 0,	/* reads */
14 	BLK_TC_WRITE	= 1 << 1,	/* writes */
15 	BLK_TC_BARRIER	= 1 << 2,	/* barrier */
16 	BLK_TC_SYNC	= 1 << 3,	/* sync IO */
17 	BLK_TC_QUEUE	= 1 << 4,	/* queueing/merging */
18 	BLK_TC_REQUEUE	= 1 << 5,	/* requeueing */
19 	BLK_TC_ISSUE	= 1 << 6,	/* issue */
20 	BLK_TC_COMPLETE	= 1 << 7,	/* completions */
21 	BLK_TC_FS	= 1 << 8,	/* fs requests */
22 	BLK_TC_PC	= 1 << 9,	/* pc requests */
23 	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
24 	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
25 	BLK_TC_META	= 1 << 12,	/* metadata */
26 	BLK_TC_DISCARD	= 1 << 13,	/* discard requests */
27 	BLK_TC_DRV_DATA	= 1 << 14,	/* binary per-driver data */
28 
29 	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
30 };
31 
32 #define BLK_TC_SHIFT		(16)
33 #define BLK_TC_ACT(act)		((act) << BLK_TC_SHIFT)
34 
35 /*
36  * Basic trace actions
37  */
38 enum blktrace_act {
39 	__BLK_TA_QUEUE = 1,		/* queued */
40 	__BLK_TA_BACKMERGE,		/* back merged to existing rq */
41 	__BLK_TA_FRONTMERGE,		/* front merge to existing rq */
42 	__BLK_TA_GETRQ,			/* allocated new request */
43 	__BLK_TA_SLEEPRQ,		/* sleeping on rq allocation */
44 	__BLK_TA_REQUEUE,		/* request requeued */
45 	__BLK_TA_ISSUE,			/* sent to driver */
46 	__BLK_TA_COMPLETE,		/* completed by driver */
47 	__BLK_TA_PLUG,			/* queue was plugged */
48 	__BLK_TA_UNPLUG_IO,		/* queue was unplugged by io */
49 	__BLK_TA_UNPLUG_TIMER,		/* queue was unplugged by timer */
50 	__BLK_TA_INSERT,		/* insert request */
51 	__BLK_TA_SPLIT,			/* bio was split */
52 	__BLK_TA_BOUNCE,		/* bio was bounced */
53 	__BLK_TA_REMAP,			/* bio was remapped */
54 	__BLK_TA_ABORT,			/* request aborted */
55 	__BLK_TA_DRV_DATA,		/* driver-specific binary data */
56 };
57 
58 /*
59  * Notify events.
60  */
61 enum blktrace_notify {
62 	__BLK_TN_PROCESS = 0,		/* establish pid/name mapping */
63 	__BLK_TN_TIMESTAMP,		/* include system clock */
64 	__BLK_TN_MESSAGE,		/* Character string message */
65 };
66 
67 
68 /*
69  * Trace actions in full. Additionally, read or write is masked
70  */
71 #define BLK_TA_QUEUE		(__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
72 #define BLK_TA_BACKMERGE	(__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
73 #define BLK_TA_FRONTMERGE	(__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
74 #define	BLK_TA_GETRQ		(__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
75 #define	BLK_TA_SLEEPRQ		(__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
76 #define	BLK_TA_REQUEUE		(__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
77 #define BLK_TA_ISSUE		(__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
78 #define BLK_TA_COMPLETE		(__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
79 #define BLK_TA_PLUG		(__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
80 #define BLK_TA_UNPLUG_IO	(__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
81 #define BLK_TA_UNPLUG_TIMER	(__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
82 #define BLK_TA_INSERT		(__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
83 #define BLK_TA_SPLIT		(__BLK_TA_SPLIT)
84 #define BLK_TA_BOUNCE		(__BLK_TA_BOUNCE)
85 #define BLK_TA_REMAP		(__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
86 #define BLK_TA_ABORT		(__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
87 #define BLK_TA_DRV_DATA	(__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))
88 
89 #define BLK_TN_PROCESS		(__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
90 #define BLK_TN_TIMESTAMP	(__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
91 #define BLK_TN_MESSAGE		(__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
92 
93 #define BLK_IO_TRACE_MAGIC	0x65617400
94 #define BLK_IO_TRACE_VERSION	0x07
95 
96 /*
97  * The trace itself
98  */
99 struct blk_io_trace {
100 	__u32 magic;		/* MAGIC << 8 | version */
101 	__u32 sequence;		/* event number */
102 	__u64 time;		/* in microseconds */
103 	__u64 sector;		/* disk offset */
104 	__u32 bytes;		/* transfer length */
105 	__u32 action;		/* what happened */
106 	__u32 pid;		/* who did it */
107 	__u32 device;		/* device number */
108 	__u32 cpu;		/* on what cpu did it happen */
109 	__u16 error;		/* completion error */
110 	__u16 pdu_len;		/* length of data after this trace */
111 };
112 
113 /*
114  * The remap event
115  */
116 struct blk_io_trace_remap {
117 	__be32 device;
118 	__be32 device_from;
119 	__be64 sector;
120 };
121 
122 enum {
123 	Blktrace_setup = 1,
124 	Blktrace_running,
125 	Blktrace_stopped,
126 };
127 
128 #define BLKTRACE_BDEV_SIZE	32
129 
130 /*
131  * User setup structure passed with BLKTRACESTART
132  */
133 struct blk_user_trace_setup {
134 	char name[BLKTRACE_BDEV_SIZE];	/* output */
135 	__u16 act_mask;			/* input */
136 	__u32 buf_size;			/* input */
137 	__u32 buf_nr;			/* input */
138 	__u64 start_lba;
139 	__u64 end_lba;
140 	__u32 pid;
141 };
142 
143 #ifdef __KERNEL__
144 #if defined(CONFIG_BLK_DEV_IO_TRACE)
145 struct blk_trace {
146 	int trace_state;
147 	struct rchan *rchan;
148 	unsigned long *sequence;
149 	unsigned char *msg_data;
150 	u16 act_mask;
151 	u64 start_lba;
152 	u64 end_lba;
153 	u32 pid;
154 	u32 dev;
155 	struct dentry *dir;
156 	struct dentry *dropped_file;
157 	struct dentry *msg_file;
158 	atomic_t dropped;
159 };
160 
161 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
162 extern void blk_trace_shutdown(struct request_queue *);
163 extern int do_blk_trace_setup(struct request_queue *q,
164 	char *name, dev_t dev, struct blk_user_trace_setup *buts);
165 extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
166 
167 /**
168  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
169  * @q:		queue the io is for
170  * @fmt:	format to print message in
171  * args...	Variable argument list for format
172  *
173  * Description:
174  *     Records a (simple) message onto the blktrace stream.
175  *
176  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
177  *     NOTE: Can not use 'static inline' due to presence of var args...
178  *
179  **/
180 #define blk_add_trace_msg(q, fmt, ...)					\
181 	do {								\
182 		struct blk_trace *bt = (q)->blk_trace;			\
183 		if (unlikely(bt))					\
184 			__trace_note_message(bt, fmt, ##__VA_ARGS__);	\
185 	} while (0)
186 #define BLK_TN_MAX_MSG		128
187 
188 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
189 				void *data, size_t len);
190 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
191 			   char __user *arg);
192 extern int blk_trace_startstop(struct request_queue *q, int start);
193 extern int blk_trace_remove(struct request_queue *q);
194 
195 #else /* !CONFIG_BLK_DEV_IO_TRACE */
196 #define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
197 #define blk_trace_shutdown(q)			do { } while (0)
198 #define do_blk_trace_setup(q, name, dev, buts)	(-ENOTTY)
199 #define blk_add_driver_data(q, rq, data, len)	do {} while (0)
200 #define blk_trace_setup(q, name, dev, arg)	(-ENOTTY)
201 #define blk_trace_startstop(q, start)		(-ENOTTY)
202 #define blk_trace_remove(q)			(-ENOTTY)
203 #define blk_add_trace_msg(q, fmt, ...)		do { } while (0)
204 
205 #endif /* CONFIG_BLK_DEV_IO_TRACE */
206 #endif /* __KERNEL__ */
207 #endif
208