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
16 struct 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
31 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
32 extern 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
blk_trace_note_message_enabled(struct request_queue * q)63 static 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
75 extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
76 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
77 struct block_device *bdev,
78 char __user *arg);
79 extern int blk_trace_startstop(struct request_queue *q, int start);
80 extern 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
blk_trace_remove(struct request_queue * q)92 static 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
100 struct 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
113 void blk_fill_rwbs(char *rwbs, blk_opf_t opf);
114
blk_rq_trace_sector(struct request * rq)115 static 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
blk_rq_trace_nr_sectors(struct request * rq)126 static 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