include/linux/blktrace_api.h

   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
  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
  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
 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
 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