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 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 = (q)->blk_trace;                  \
  55                 if (unlikely(bt))                                       \
  56                         __trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\
  57         } while (0)
  58 #define blk_add_trace_msg(q, fmt, ...)                                  \
  59         blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
  60 #define BLK_TN_MAX_MSG          128
  61
  62 static inline bool blk_trace_note_message_enabled(struct request_queue *q)
  63 {
  64         struct blk_trace *bt = q->blk_trace;
  65         if (likely(!bt))
  66                 return false;
  67         return bt->act_mask & BLK_TC_NOTIFY;
  68 }
  69
  70 extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
  71                                 void *data, size_t len);
  72 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
  73                            struct block_device *bdev,
  74                            char __user *arg);
  75 extern int blk_trace_startstop(struct request_queue *q, int start);
  76 extern int blk_trace_remove(struct request_queue *q);
  77 extern void blk_trace_remove_sysfs(struct device *dev);
  78 extern int blk_trace_init_sysfs(struct device *dev);
  79
  80 extern struct attribute_group blk_trace_attr_group;
  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(q, 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_trace_remove(q)                            (-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_remove_sysfs(dev)                    do { } while (0)
  92 # define blk_trace_note_message_enabled(q)              (false)
  93 static inline int blk_trace_init_sysfs(struct device *dev)
  94 {
  95         return 0;
  96 }
  97
  98 #endif /* CONFIG_BLK_DEV_IO_TRACE */
  99
 100 #ifdef CONFIG_COMPAT
 101
 102 struct compat_blk_user_trace_setup {
 103         char name[BLKTRACE_BDEV_SIZE];
 104         u16 act_mask;
 105         u32 buf_size;
 106         u32 buf_nr;
 107         compat_u64 start_lba;
 108         compat_u64 end_lba;
 109         u32 pid;
 110 };
 111 #define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
 112
 113 #endif
 114
 115 extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
 116
 117 static inline sector_t blk_rq_trace_sector(struct request *rq)
 118 {
 119         /*
 120          * Tracing should ignore starting sector for passthrough requests and
 121          * requests where starting sector didn't get set.
 122          */
 123         if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
 124                 return 0;
 125         return blk_rq_pos(rq);
 126 }
 127
 128 static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
 129 {
 130         return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
 131 }
 132
 133 #endif