include/linux/blktrace_api.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef BLKTRACE_H
   3 #define BLKTRACE_H
   4
   5 #include <linux/blkdev.h>
   6 #include <linux/relay.h>
   7 #include <linux/compat.h>
   8 #include <uapi/linux/blktrace_api.h>
   9 #include <linux/list.h>
  10
  11 #if defined(CONFIG_BLK_DEV_IO_TRACE)
  12
  13 #include <linux/sysfs.h>
  14
  15 struct blk_trace {
  16         int trace_state;
  17         struct rchan *rchan;
  18         unsigned long __percpu *sequence;
  19         unsigned char __percpu *msg_data;
  20         u16 act_mask;
  21         u64 start_lba;
  22         u64 end_lba;
  23         u32 pid;
  24         u32 dev;
  25         struct dentry *dir;
  26         struct list_head running_list;
  27         atomic_t dropped;
  28 };
  29
  30 struct blkcg;
  31
  32 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
  33 extern void blk_trace_shutdown(struct request_queue *);
  34 extern __printf(3, 4)
  35 void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, 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, cg, 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                         __trace_note_message(bt, cg, 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
  64 static 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
  76 extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
  77 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
  78                            struct block_device *bdev,
  79                            char __user *arg);
  80 extern int blk_trace_startstop(struct request_queue *q, int start);
  81 extern int blk_trace_remove(struct request_queue *q);
  82 extern void blk_trace_remove_sysfs(struct device *dev);
  83 extern int blk_trace_init_sysfs(struct device *dev);
  84
  85 extern struct attribute_group blk_trace_attr_group;
  86
  87 #else /* !CONFIG_BLK_DEV_IO_TRACE */
  88 # define blk_trace_ioctl(bdev, cmd, arg)                (-ENOTTY)
  89 # define blk_trace_shutdown(q)                          do { } while (0)
  90 # define blk_add_driver_data(rq, data, len)             do {} while (0)
  91 # define blk_trace_setup(q, name, dev, bdev, arg)       (-ENOTTY)
  92 # define blk_trace_startstop(q, start)                  (-ENOTTY)
  93 # define blk_trace_remove(q)                            (-ENOTTY)
  94 # define blk_add_trace_msg(q, fmt, ...)                 do { } while (0)
  95 # define blk_add_cgroup_trace_msg(q, cg, fmt, ...)      do { } while (0)
  96 # define blk_trace_remove_sysfs(dev)                    do { } while (0)
  97 # define blk_trace_note_message_enabled(q)              (false)
  98 static inline int blk_trace_init_sysfs(struct device *dev)
  99 {
 100         return 0;
 101 }
 102
 103 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 104
 105 #ifdef CONFIG_COMPAT
 106
 107 struct compat_blk_user_trace_setup {
 108         char name[BLKTRACE_BDEV_SIZE];
 109         u16 act_mask;
 110         u32 buf_size;
 111         u32 buf_nr;
 112         compat_u64 start_lba;
 113         compat_u64 end_lba;
 114         u32 pid;
 115 };
 116 #define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
 117
 118 #endif
 119
 120 void blk_fill_rwbs(char *rwbs, unsigned int op);
 121
 122 static inline sector_t blk_rq_trace_sector(struct request *rq)
 123 {
 124         /*
 125          * Tracing should ignore starting sector for passthrough requests and
 126          * requests where starting sector didn't get set.
 127          */
 128         if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
 129                 return 0;
 130         return blk_rq_pos(rq);
 131 }
 132
 133 static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
 134 {
 135         return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
 136 }
 137
 138 #endif