1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef BLKTRACE_H
3#define BLKTRACE_H
4
5#include <linux/blk-mq.h>
6#include <linux/relay.h>
7#include <linux/compat.h>
8#include <uapi/linux/blktrace_api.h>
9#include <linux/list.h>
10#include <linux/blk_types.h>
11
12#if defined(CONFIG_BLK_DEV_IO_TRACE)
13
14#include <linux/sysfs.h>
15
16struct blk_trace {
17 int trace_state;
18 struct rchan *rchan;
19 unsigned long __percpu *sequence;
20 unsigned char __percpu *msg_data;
21 u16 act_mask;
22 u64 start_lba;
23 u64 end_lba;
24 u32 pid;
25 u32 dev;
26 struct dentry *dir;
27 struct list_head running_list;
28 atomic_t dropped;
29};
30
31extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
32extern void blk_trace_shutdown(struct request_queue *);
33__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
34 struct cgroup_subsys_state *css, const char *fmt, ...);
35
36/**
37 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
38 * @q: queue the io is for
39 * @fmt: format to print message in
40 * args... Variable argument list for format
41 *
42 * Description:
43 * Records a (simple) message onto the blktrace stream.
44 *
45 * NOTE: BLK_TN_MAX_MSG characters are output at most.
46 * NOTE: Can not use 'static inline' due to presence of var args...
47 *
48 **/
49#define blk_add_cgroup_trace_msg(q, css, fmt, ...) \
50 do { \
51 struct blk_trace *bt; \
52 \
53 rcu_read_lock(); \
54 bt = rcu_dereference((q)->blk_trace); \
55 if (unlikely(bt)) \
56 __blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
57 rcu_read_unlock(); \
58 } while (0)
59#define blk_add_trace_msg(q, fmt, ...) \
60 blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
61#define BLK_TN_MAX_MSG 128
62
63static inline bool blk_trace_note_message_enabled(struct request_queue *q)
64{
65 struct blk_trace *bt;
66 bool ret;
67
68 rcu_read_lock();
69 bt = rcu_dereference(q->blk_trace);
70 ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
71 rcu_read_unlock();
72 return ret;
73}
74
75extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
76extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
77 struct block_device *bdev,
78 char __user *arg);
79extern int blk_trace_startstop(struct request_queue *q, int start);
80extern int blk_trace_remove(struct request_queue *q);
81
82#else /* !CONFIG_BLK_DEV_IO_TRACE */
83# define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
84# define blk_trace_shutdown(q) do { } while (0)
85# define blk_add_driver_data(rq, data, len) do {} while (0)
86# define blk_trace_setup(q, name, dev, bdev, arg) (-ENOTTY)
87# define blk_trace_startstop(q, start) (-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_note_message_enabled(q) (false)
91
92static inline int blk_trace_remove(struct request_queue *q)
93{
94 return -ENOTTY;
95}
96#endif /* CONFIG_BLK_DEV_IO_TRACE */
97
98#ifdef CONFIG_COMPAT
99
100struct compat_blk_user_trace_setup {
101 char name[BLKTRACE_BDEV_SIZE];
102 u16 act_mask;
103 u32 buf_size;
104 u32 buf_nr;
105 compat_u64 start_lba;
106 compat_u64 end_lba;
107 u32 pid;
108};
109#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
110
111#endif
112
113void blk_fill_rwbs(char *rwbs, blk_opf_t opf);
114
115static inline sector_t blk_rq_trace_sector(struct request *rq)
116{
117 /*
118 * Tracing should ignore starting sector for passthrough requests and
119 * requests where starting sector didn't get set.
120 */
121 if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
122 return 0;
123 return blk_rq_pos(rq);
124}
125
126static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
127{
128 return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
129}
130
131#endif
132

source code of linux/include/linux/blktrace_api.h

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