blktrace_api.h revision 4502b80e44f1fc9af33f66053c6c99ae9dba32a6 
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 */
13enum 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_QUEUE	= 1 << 4,	/* queueing/merging */
19	BLK_TC_REQUEUE	= 1 << 5,	/* requeueing */
20	BLK_TC_ISSUE	= 1 << 6,	/* issue */
21	BLK_TC_COMPLETE	= 1 << 7,	/* completions */
22	BLK_TC_FS	= 1 << 8,	/* fs requests */
23	BLK_TC_PC	= 1 << 9,	/* pc requests */
24	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
25	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
26	BLK_TC_META	= 1 << 12,	/* metadata */
27	BLK_TC_DISCARD	= 1 << 13,	/* discard requests */
28	BLK_TC_DRV_DATA	= 1 << 14,	/* binary per-driver data */
29
30	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
31};
32
33#define BLK_TC_SHIFT		(16)
34#define BLK_TC_ACT(act)		((act) << BLK_TC_SHIFT)
35
36/*
37 * Basic trace actions
38 */
39enum blktrace_act {
40	__BLK_TA_QUEUE = 1,		/* queued */
41	__BLK_TA_BACKMERGE,		/* back merged to existing rq */
42	__BLK_TA_FRONTMERGE,		/* front merge to existing rq */
43	__BLK_TA_GETRQ,			/* allocated new request */
44	__BLK_TA_SLEEPRQ,		/* sleeping on rq allocation */
45	__BLK_TA_REQUEUE,		/* request requeued */
46	__BLK_TA_ISSUE,			/* sent to driver */
47	__BLK_TA_COMPLETE,		/* completed by driver */
48	__BLK_TA_PLUG,			/* queue was plugged */
49	__BLK_TA_UNPLUG_IO,		/* queue was unplugged by io */
50	__BLK_TA_UNPLUG_TIMER,		/* queue was unplugged by timer */
51	__BLK_TA_INSERT,		/* insert request */
52	__BLK_TA_SPLIT,			/* bio was split */
53	__BLK_TA_BOUNCE,		/* bio was bounced */
54	__BLK_TA_REMAP,			/* bio was remapped */
55	__BLK_TA_ABORT,			/* request aborted */
56	__BLK_TA_DRV_DATA,		/* driver-specific binary data */
57};
58
59/*
60 * Notify events.
61 */
62enum blktrace_notify {
63	__BLK_TN_PROCESS = 0,		/* establish pid/name mapping */
64	__BLK_TN_TIMESTAMP,		/* include system clock */
65	__BLK_TN_MESSAGE,		/* Character string message */
66};
67
68
69/*
70 * Trace actions in full. Additionally, read or write is masked
71 */
72#define BLK_TA_QUEUE		(__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
73#define BLK_TA_BACKMERGE	(__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
74#define BLK_TA_FRONTMERGE	(__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
75#define	BLK_TA_GETRQ		(__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
76#define	BLK_TA_SLEEPRQ		(__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
77#define	BLK_TA_REQUEUE		(__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
78#define BLK_TA_ISSUE		(__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
79#define BLK_TA_COMPLETE		(__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
80#define BLK_TA_PLUG		(__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
81#define BLK_TA_UNPLUG_IO	(__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
82#define BLK_TA_UNPLUG_TIMER	(__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
83#define BLK_TA_INSERT		(__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
84#define BLK_TA_SPLIT		(__BLK_TA_SPLIT)
85#define BLK_TA_BOUNCE		(__BLK_TA_BOUNCE)
86#define BLK_TA_REMAP		(__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
87#define BLK_TA_ABORT		(__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
88#define BLK_TA_DRV_DATA	(__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))
89
90#define BLK_TN_PROCESS		(__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
91#define BLK_TN_TIMESTAMP	(__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
92#define BLK_TN_MESSAGE		(__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
93
94#define BLK_IO_TRACE_MAGIC	0x65617400
95#define BLK_IO_TRACE_VERSION	0x07
96
97/*
98 * The trace itself
99 */
100struct blk_io_trace {
101	__u32 magic;		/* MAGIC << 8 | version */
102	__u32 sequence;		/* event number */
103	__u64 time;		/* in microseconds */
104	__u64 sector;		/* disk offset */
105	__u32 bytes;		/* transfer length */
106	__u32 action;		/* what happened */
107	__u32 pid;		/* who did it */
108	__u32 device;		/* device number */
109	__u32 cpu;		/* on what cpu did it happen */
110	__u16 error;		/* completion error */
111	__u16 pdu_len;		/* length of data after this trace */
112};
113
114/*
115 * The remap event
116 */
117struct blk_io_trace_remap {
118	__be32 device;
119	__be32 device_from;
120	__be64 sector;
121};
122
123enum {
124	Blktrace_setup = 1,
125	Blktrace_running,
126	Blktrace_stopped,
127};
128
129#define BLKTRACE_BDEV_SIZE	32
130
131/*
132 * User setup structure passed with BLKTRACESTART
133 */
134struct blk_user_trace_setup {
135	char name[BLKTRACE_BDEV_SIZE];	/* output */
136	__u16 act_mask;			/* input */
137	__u32 buf_size;			/* input */
138	__u32 buf_nr;			/* input */
139	__u64 start_lba;
140	__u64 end_lba;
141	__u32 pid;
142};
143
144#ifdef __KERNEL__
145#if defined(CONFIG_BLK_DEV_IO_TRACE)
146struct blk_trace {
147	int trace_state;
148	struct rchan *rchan;
149	unsigned long *sequence;
150	unsigned char *msg_data;
151	u16 act_mask;
152	u64 start_lba;
153	u64 end_lba;
154	u32 pid;
155	u32 dev;
156	struct dentry *dir;
157	struct dentry *dropped_file;
158	struct dentry *msg_file;
159	atomic_t dropped;
160};
161
162extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
163extern void blk_trace_shutdown(struct request_queue *);
164extern int do_blk_trace_setup(struct request_queue *q,
165	char *name, dev_t dev, struct blk_user_trace_setup *buts);
166extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
167
168/**
169 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
170 * @q:		queue the io is for
171 * @fmt:	format to print message in
172 * args...	Variable argument list for format
173 *
174 * Description:
175 *     Records a (simple) message onto the blktrace stream.
176 *
177 *     NOTE: BLK_TN_MAX_MSG characters are output at most.
178 *     NOTE: Can not use 'static inline' due to presence of var args...
179 *
180 **/
181#define blk_add_trace_msg(q, fmt, ...)					\
182	do {								\
183		struct blk_trace *bt = (q)->blk_trace;			\
184		if (unlikely(bt))					\
185			__trace_note_message(bt, fmt, ##__VA_ARGS__);	\
186	} while (0)
187#define BLK_TN_MAX_MSG		128
188
189extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
190				void *data, size_t len);
191extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
192			   char __user *arg);
193extern int blk_trace_startstop(struct request_queue *q, int start);
194extern int blk_trace_remove(struct request_queue *q);
195
196#else /* !CONFIG_BLK_DEV_IO_TRACE */
197#define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
198#define blk_trace_shutdown(q)			do { } while (0)
199#define do_blk_trace_setup(q, name, dev, buts)	(-ENOTTY)
200#define blk_add_driver_data(q, rq, data, len)	do {} while (0)
201#define blk_trace_setup(q, name, dev, arg)	(-ENOTTY)
202#define blk_trace_startstop(q, start)		(-ENOTTY)
203#define blk_trace_remove(q)			(-ENOTTY)
204#define blk_add_trace_msg(q, fmt, ...)		do { } while (0)
205
206#endif /* CONFIG_BLK_DEV_IO_TRACE */
207#endif /* __KERNEL__ */
208#endif
209