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 list_head running_list;
  27        atomic_t dropped;
  28};
  29
  30struct blkcg;
  31
  32extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
  33extern void blk_trace_shutdown(struct request_queue *);
  34extern __printf(3, 4)
  35void __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
  64static 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
  76extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
  77extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
  78                           struct block_device *bdev,
  79                           char __user *arg);
  80extern int blk_trace_startstop(struct request_queue *q, int start);
  81extern int blk_trace_remove(struct request_queue *q);
  82extern void blk_trace_remove_sysfs(struct device *dev);
  83extern int blk_trace_init_sysfs(struct device *dev);
  84
  85extern 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)
  98static 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
 107struct 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
 120void blk_fill_rwbs(char *rwbs, unsigned int op);
 121
 122static 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
 133static 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
 139