Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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 version;
18 int trace_state;
19 struct rchan *rchan;
20 unsigned long __percpu *sequence;
21 unsigned char __percpu *msg_data;
22 u64 act_mask;
23 u64 start_lba;
24 u64 end_lba;
25 u32 pid;
26 u32 dev;
27 struct dentry *dir;
28 struct list_head running_list;
29 atomic_t dropped;
30};
31
32extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
33extern void blk_trace_shutdown(struct request_queue *);
34__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
35 struct cgroup_subsys_state *css, const char *fmt, ...);
36
37/**
38 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
39 * @q: queue the io is for
40 * @fmt: format to print message in
41 * args... Variable argument list for format
42 *
43 * Description:
44 * Records a (simple) message onto the blktrace stream.
45 *
46 * NOTE: BLK_TN_MAX_MSG characters are output at most.
47 * NOTE: Can not use 'static inline' due to presence of var args...
48 *
49 **/
50#define blk_add_cgroup_trace_msg(q, css, fmt, ...) \
51 do { \
52 struct blk_trace *bt; \
53 \
54 rcu_read_lock(); \
55 bt = rcu_dereference((q)->blk_trace); \
56 if (unlikely(bt)) \
57 __blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
58 rcu_read_unlock(); \
59 } while (0)
60#define blk_add_trace_msg(q, fmt, ...) \
61 blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
62#define BLK_TN_MAX_MSG 128
63
64static inline bool blk_trace_note_message_enabled(struct request_queue *q)
65{
66 struct blk_trace *bt;
67 bool ret;
68
69 rcu_read_lock();
70 bt = rcu_dereference(q->blk_trace);
71 ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
72 rcu_read_unlock();
73 return ret;
74}
75
76extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
77extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
78 struct block_device *bdev,
79 char __user *arg);
80extern int blk_trace_startstop(struct request_queue *q, int start);
81extern int blk_trace_remove(struct request_queue *q);
82
83#else /* !CONFIG_BLK_DEV_IO_TRACE */
84# define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
85# define blk_trace_shutdown(q) do { } while (0)
86# define blk_add_driver_data(rq, data, len) do {} while (0)
87# define blk_trace_setup(q, name, dev, bdev, arg) (-ENOTTY)
88# define blk_trace_startstop(q, start) (-ENOTTY)
89# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
90# define blk_add_cgroup_trace_msg(q, cg, fmt, ...) do { } while (0)
91# define blk_trace_note_message_enabled(q) (false)
92
93static inline int blk_trace_remove(struct request_queue *q)
94{
95 return -ENOTTY;
96}
97#endif /* CONFIG_BLK_DEV_IO_TRACE */
98
99#ifdef CONFIG_COMPAT
100
101struct 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
114void blk_fill_rwbs(char *rwbs, blk_opf_t opf);
115
116static inline sector_t blk_rq_trace_sector(struct request *rq)
117{
118 /*
119 * Tracing should ignore starting sector for passthrough requests and
120 * requests where starting sector didn't get set.
121 */
122 if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
123 return 0;
124 return blk_rq_pos(rq);
125}
126
127static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
128{
129 return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
130}
131
132#endif