LXR linux/include/linux/blktrace

   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
  15struct 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
  32struct blkcg;
  33
  34extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
  35extern void blk_trace_shutdown(struct request_queue *);
  36extern __printf(3, 4)
  37void __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
  66static 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
  78extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
  79                                void *data, size_t len);
  80extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
  81                           struct block_device *bdev,
  82                           char __user *arg);
  83extern int blk_trace_startstop(struct request_queue *q, int start);
  84extern int blk_trace_remove(struct request_queue *q);
  85extern void blk_trace_remove_sysfs(struct device *dev);
  86extern int blk_trace_init_sysfs(struct device *dev);
  87
  88extern 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)
 101static 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
 110struct 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
 123extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
 124
 125static 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
 136static 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
 142