root/include/linux/blktrace_api.h

INCLUDED FROM

DEFINITIONS

1. blk_trace_note_message_enabled
2. blk_trace_init_sysfs
3. blk_rq_trace_sector
4. blk_rq_trace_nr_sectors

   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 dentry *dropped_file;
  27         struct dentry *msg_file;
  28         struct list_head running_list;
  29         atomic_t dropped;
  30 };
  31 
  32 struct blkcg;
  33 
  34 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
  35 extern void blk_trace_shutdown(struct request_queue *);
  36 extern __printf(3, 4)
  37 void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, const char *fmt, ...);
  38 
  39 /**
  40  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
  41  * @q:          queue the io is for
  42  * @fmt:        format to print message in
  43  * args...      Variable argument list for format
  44  *
  45  * Description:
  46  *     Records a (simple) message onto the blktrace stream.
  47  *
  48  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
  49  *     NOTE: Can not use 'static inline' due to presence of var args...
  50  *
  51  **/
  52 #define blk_add_cgroup_trace_msg(q, cg, fmt, ...)                       \
  53         do {                                                            \
  54                 struct blk_trace *bt;                                   \
  55                                                                         \
  56                 rcu_read_lock();                                        \
  57                 bt = rcu_dereference((q)->blk_trace);                   \
  58                 if (unlikely(bt))                                       \
  59                         __trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\
  60                 rcu_read_unlock();                                      \
  61         } while (0)
  62 #define blk_add_trace_msg(q, fmt, ...)                                  \
  63         blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
  64 #define BLK_TN_MAX_MSG          128
  65 
  66 static inline bool blk_trace_note_message_enabled(struct request_queue *q)
  67 {
  68         struct blk_trace *bt;
  69         bool ret;
  70 
  71         rcu_read_lock();
  72         bt = rcu_dereference(q->blk_trace);
  73         ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
  74         rcu_read_unlock();
  75         return ret;
  76 }
  77 
  78 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
  79                                 void *data, size_t len);
  80 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
  81                            struct block_device *bdev,
  82                            char __user *arg);
  83 extern int blk_trace_startstop(struct request_queue *q, int start);
  84 extern int blk_trace_remove(struct request_queue *q);
  85 extern void blk_trace_remove_sysfs(struct device *dev);
  86 extern int blk_trace_init_sysfs(struct device *dev);
  87 
  88 extern struct attribute_group blk_trace_attr_group;
  89 
  90 #else /* !CONFIG_BLK_DEV_IO_TRACE */
  91 # define blk_trace_ioctl(bdev, cmd, arg)                (-ENOTTY)
  92 # define blk_trace_shutdown(q)                          do { } while (0)
  93 # define blk_add_driver_data(q, rq, data, len)          do {} while (0)
  94 # define blk_trace_setup(q, name, dev, bdev, arg)       (-ENOTTY)
  95 # define blk_trace_startstop(q, start)                  (-ENOTTY)
  96 # define blk_trace_remove(q)                            (-ENOTTY)
  97 # define blk_add_trace_msg(q, fmt, ...)                 do { } while (0)
  98 # define blk_add_cgroup_trace_msg(q, cg, fmt, ...)      do { } while (0)
  99 # define blk_trace_remove_sysfs(dev)                    do { } while (0)
 100 # define blk_trace_note_message_enabled(q)              (false)
 101 static inline int blk_trace_init_sysfs(struct device *dev)
 102 {
 103         return 0;
 104 }
 105 
 106 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 107 
 108 #ifdef CONFIG_COMPAT
 109 
 110 struct compat_blk_user_trace_setup {
 111         char name[BLKTRACE_BDEV_SIZE];
 112         u16 act_mask;
 113         u32 buf_size;
 114         u32 buf_nr;
 115         compat_u64 start_lba;
 116         compat_u64 end_lba;
 117         u32 pid;
 118 };
 119 #define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
 120 
 121 #endif
 122 
 123 extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
 124 
 125 static inline sector_t blk_rq_trace_sector(struct request *rq)
 126 {
 127         /*
 128          * Tracing should ignore starting sector for passthrough requests and
 129          * requests where starting sector didn't get set.
 130          */
 131         if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
 132                 return 0;
 133         return blk_rq_pos(rq);
 134 }
 135 
 136 static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
 137 {
 138         return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
 139 }
 140 
 141 #endif