xref: /linux-6.15/include/linux/blktrace_api.h (revision a115bc07)
1 #ifndef BLKTRACE_H
2 #define BLKTRACE_H
3 
4 #include <linux/types.h>
5 #ifdef __KERNEL__
6 #include <linux/blkdev.h>
7 #include <linux/relay.h>
8 #endif
9 
10 /*
11  * Trace categories
12  */
13 enum blktrace_cat {
14 	BLK_TC_READ	= 1 << 0,	/* reads */
15 	BLK_TC_WRITE	= 1 << 1,	/* writes */
16 	BLK_TC_BARRIER	= 1 << 2,	/* barrier */
17 	BLK_TC_SYNC	= 1 << 3,	/* sync IO */
18 	BLK_TC_SYNCIO	= BLK_TC_SYNC,
19 	BLK_TC_QUEUE	= 1 << 4,	/* queueing/merging */
20 	BLK_TC_REQUEUE	= 1 << 5,	/* requeueing */
21 	BLK_TC_ISSUE	= 1 << 6,	/* issue */
22 	BLK_TC_COMPLETE	= 1 << 7,	/* completions */
23 	BLK_TC_FS	= 1 << 8,	/* fs requests */
24 	BLK_TC_PC	= 1 << 9,	/* pc requests */
25 	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
26 	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
27 	BLK_TC_META	= 1 << 12,	/* metadata */
28 	BLK_TC_DISCARD	= 1 << 13,	/* discard requests */
29 	BLK_TC_DRV_DATA	= 1 << 14,	/* binary per-driver data */
30 
31 	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
32 };
33 
34 #define BLK_TC_SHIFT		(16)
35 #define BLK_TC_ACT(act)		((act) << BLK_TC_SHIFT)
36 
37 /*
38  * Basic trace actions
39  */
40 enum blktrace_act {
41 	__BLK_TA_QUEUE = 1,		/* queued */
42 	__BLK_TA_BACKMERGE,		/* back merged to existing rq */
43 	__BLK_TA_FRONTMERGE,		/* front merge to existing rq */
44 	__BLK_TA_GETRQ,			/* allocated new request */
45 	__BLK_TA_SLEEPRQ,		/* sleeping on rq allocation */
46 	__BLK_TA_REQUEUE,		/* request requeued */
47 	__BLK_TA_ISSUE,			/* sent to driver */
48 	__BLK_TA_COMPLETE,		/* completed by driver */
49 	__BLK_TA_PLUG,			/* queue was plugged */
50 	__BLK_TA_UNPLUG_IO,		/* queue was unplugged by io */
51 	__BLK_TA_UNPLUG_TIMER,		/* queue was unplugged by timer */
52 	__BLK_TA_INSERT,		/* insert request */
53 	__BLK_TA_SPLIT,			/* bio was split */
54 	__BLK_TA_BOUNCE,		/* bio was bounced */
55 	__BLK_TA_REMAP,			/* bio was remapped */
56 	__BLK_TA_ABORT,			/* request aborted */
57 	__BLK_TA_DRV_DATA,		/* driver-specific binary data */
58 };
59 
60 /*
61  * Notify events.
62  */
63 enum blktrace_notify {
64 	__BLK_TN_PROCESS = 0,		/* establish pid/name mapping */
65 	__BLK_TN_TIMESTAMP,		/* include system clock */
66 	__BLK_TN_MESSAGE,		/* Character string message */
67 };
68 
69 
70 /*
71  * Trace actions in full. Additionally, read or write is masked
72  */
73 #define BLK_TA_QUEUE		(__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
74 #define BLK_TA_BACKMERGE	(__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
75 #define BLK_TA_FRONTMERGE	(__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
76 #define	BLK_TA_GETRQ		(__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
77 #define	BLK_TA_SLEEPRQ		(__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
78 #define	BLK_TA_REQUEUE		(__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
79 #define BLK_TA_ISSUE		(__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
80 #define BLK_TA_COMPLETE		(__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
81 #define BLK_TA_PLUG		(__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
82 #define BLK_TA_UNPLUG_IO	(__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
83 #define BLK_TA_UNPLUG_TIMER	(__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
84 #define BLK_TA_INSERT		(__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
85 #define BLK_TA_SPLIT		(__BLK_TA_SPLIT)
86 #define BLK_TA_BOUNCE		(__BLK_TA_BOUNCE)
87 #define BLK_TA_REMAP		(__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
88 #define BLK_TA_ABORT		(__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
89 #define BLK_TA_DRV_DATA	(__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))
90 
91 #define BLK_TN_PROCESS		(__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
92 #define BLK_TN_TIMESTAMP	(__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
93 #define BLK_TN_MESSAGE		(__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
94 
95 #define BLK_IO_TRACE_MAGIC	0x65617400
96 #define BLK_IO_TRACE_VERSION	0x07
97 
98 /*
99  * The trace itself
100  */
101 struct blk_io_trace {
102 	__u32 magic;		/* MAGIC << 8 | version */
103 	__u32 sequence;		/* event number */
104 	__u64 time;		/* in microseconds */
105 	__u64 sector;		/* disk offset */
106 	__u32 bytes;		/* transfer length */
107 	__u32 action;		/* what happened */
108 	__u32 pid;		/* who did it */
109 	__u32 device;		/* device number */
110 	__u32 cpu;		/* on what cpu did it happen */
111 	__u16 error;		/* completion error */
112 	__u16 pdu_len;		/* length of data after this trace */
113 };
114 
115 /*
116  * The remap event
117  */
118 struct blk_io_trace_remap {
119 	__be32 device_from;
120 	__be32 device_to;
121 	__be64 sector_from;
122 };
123 
124 enum {
125 	Blktrace_setup = 1,
126 	Blktrace_running,
127 	Blktrace_stopped,
128 };
129 
130 #define BLKTRACE_BDEV_SIZE	32
131 
132 /*
133  * User setup structure passed with BLKTRACESTART
134  */
135 struct blk_user_trace_setup {
136 	char name[BLKTRACE_BDEV_SIZE];	/* output */
137 	__u16 act_mask;			/* input */
138 	__u32 buf_size;			/* input */
139 	__u32 buf_nr;			/* input */
140 	__u64 start_lba;
141 	__u64 end_lba;
142 	__u32 pid;
143 };
144 
145 #ifdef __KERNEL__
146 #if defined(CONFIG_BLK_DEV_IO_TRACE)
147 
148 #include <linux/sysfs.h>
149 
150 struct blk_trace {
151 	int trace_state;
152 	struct rchan *rchan;
153 	unsigned long __percpu *sequence;
154 	unsigned char __percpu *msg_data;
155 	u16 act_mask;
156 	u64 start_lba;
157 	u64 end_lba;
158 	u32 pid;
159 	u32 dev;
160 	struct dentry *dir;
161 	struct dentry *dropped_file;
162 	struct dentry *msg_file;
163 	atomic_t dropped;
164 };
165 
166 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
167 extern void blk_trace_shutdown(struct request_queue *);
168 extern int do_blk_trace_setup(struct request_queue *q, char *name,
169 			      dev_t dev, struct block_device *bdev,
170 			      struct blk_user_trace_setup *buts);
171 extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
172 
173 /**
174  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
175  * @q:		queue the io is for
176  * @fmt:	format to print message in
177  * args...	Variable argument list for format
178  *
179  * Description:
180  *     Records a (simple) message onto the blktrace stream.
181  *
182  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
183  *     NOTE: Can not use 'static inline' due to presence of var args...
184  *
185  **/
186 #define blk_add_trace_msg(q, fmt, ...)					\
187 	do {								\
188 		struct blk_trace *bt = (q)->blk_trace;			\
189 		if (unlikely(bt))					\
190 			__trace_note_message(bt, fmt, ##__VA_ARGS__);	\
191 	} while (0)
192 #define BLK_TN_MAX_MSG		128
193 
194 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
195 				void *data, size_t len);
196 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
197 			   struct block_device *bdev,
198 			   char __user *arg);
199 extern int blk_trace_startstop(struct request_queue *q, int start);
200 extern int blk_trace_remove(struct request_queue *q);
201 extern void blk_trace_remove_sysfs(struct device *dev);
202 extern int blk_trace_init_sysfs(struct device *dev);
203 
204 extern struct attribute_group blk_trace_attr_group;
205 
206 #else /* !CONFIG_BLK_DEV_IO_TRACE */
207 # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
208 # define blk_trace_shutdown(q)				do { } while (0)
209 # define do_blk_trace_setup(q, name, dev, bdev, buts)	(-ENOTTY)
210 # define blk_add_driver_data(q, rq, data, len)		do {} while (0)
211 # define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
212 # define blk_trace_startstop(q, start)			(-ENOTTY)
213 # define blk_trace_remove(q)				(-ENOTTY)
214 # define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
215 # define blk_trace_remove_sysfs(dev)			do { } while (0)
216 static inline int blk_trace_init_sysfs(struct device *dev)
217 {
218 	return 0;
219 }
220 
221 #endif /* CONFIG_BLK_DEV_IO_TRACE */
222 
223 #if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
224 
225 static inline int blk_cmd_buf_len(struct request *rq)
226 {
227 	return blk_pc_request(rq) ? rq->cmd_len * 3 : 1;
228 }
229 
230 extern void blk_dump_cmd(char *buf, struct request *rq);
231 extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
232 extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);
233 
234 #endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
235 
236 #endif /* __KERNEL__ */
237 #endif
238