linux/include/linux/blktrace_api.h
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   1#ifndef BLKTRACE_H
   2#define BLKTRACE_H
   3
   4#include <linux/types.h>
   5#ifdef __KERNEL__
   6#include <linux/blkdev.h>
   7#include <linux/relay.h>
   8#include <linux/compat.h>
   9#endif
  10
  11/*
  12 * Trace categories
  13 */
  14enum blktrace_cat {
  15        BLK_TC_READ     = 1 << 0,       /* reads */
  16        BLK_TC_WRITE    = 1 << 1,       /* writes */
  17        BLK_TC_FLUSH    = 1 << 2,       /* flush */
  18        BLK_TC_SYNC     = 1 << 3,       /* sync IO */
  19        BLK_TC_SYNCIO   = BLK_TC_SYNC,
  20        BLK_TC_QUEUE    = 1 << 4,       /* queueing/merging */
  21        BLK_TC_REQUEUE  = 1 << 5,       /* requeueing */
  22        BLK_TC_ISSUE    = 1 << 6,       /* issue */
  23        BLK_TC_COMPLETE = 1 << 7,       /* completions */
  24        BLK_TC_FS       = 1 << 8,       /* fs requests */
  25        BLK_TC_PC       = 1 << 9,       /* pc requests */
  26        BLK_TC_NOTIFY   = 1 << 10,      /* special message */
  27        BLK_TC_AHEAD    = 1 << 11,      /* readahead */
  28        BLK_TC_META     = 1 << 12,      /* metadata */
  29        BLK_TC_DISCARD  = 1 << 13,      /* discard requests */
  30        BLK_TC_DRV_DATA = 1 << 14,      /* binary per-driver data */
  31        BLK_TC_FUA      = 1 << 15,      /* fua requests */
  32
  33        BLK_TC_END      = 1 << 15,      /* we've run out of bits! */
  34};
  35
  36#define BLK_TC_SHIFT            (16)
  37#define BLK_TC_ACT(act)         ((act) << BLK_TC_SHIFT)
  38
  39/*
  40 * Basic trace actions
  41 */
  42enum blktrace_act {
  43        __BLK_TA_QUEUE = 1,             /* queued */
  44        __BLK_TA_BACKMERGE,             /* back merged to existing rq */
  45        __BLK_TA_FRONTMERGE,            /* front merge to existing rq */
  46        __BLK_TA_GETRQ,                 /* allocated new request */
  47        __BLK_TA_SLEEPRQ,               /* sleeping on rq allocation */
  48        __BLK_TA_REQUEUE,               /* request requeued */
  49        __BLK_TA_ISSUE,                 /* sent to driver */
  50        __BLK_TA_COMPLETE,              /* completed by driver */
  51        __BLK_TA_PLUG,                  /* queue was plugged */
  52        __BLK_TA_UNPLUG_IO,             /* queue was unplugged by io */
  53        __BLK_TA_UNPLUG_TIMER,          /* queue was unplugged by timer */
  54        __BLK_TA_INSERT,                /* insert request */
  55        __BLK_TA_SPLIT,                 /* bio was split */
  56        __BLK_TA_BOUNCE,                /* bio was bounced */
  57        __BLK_TA_REMAP,                 /* bio was remapped */
  58        __BLK_TA_ABORT,                 /* request aborted */
  59        __BLK_TA_DRV_DATA,              /* driver-specific binary data */
  60};
  61
  62/*
  63 * Notify events.
  64 */
  65enum blktrace_notify {
  66        __BLK_TN_PROCESS = 0,           /* establish pid/name mapping */
  67        __BLK_TN_TIMESTAMP,             /* include system clock */
  68        __BLK_TN_MESSAGE,               /* Character string message */
  69};
  70
  71
  72/*
  73 * Trace actions in full. Additionally, read or write is masked
  74 */
  75#define BLK_TA_QUEUE            (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
  76#define BLK_TA_BACKMERGE        (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  77#define BLK_TA_FRONTMERGE       (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  78#define BLK_TA_GETRQ            (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  79#define BLK_TA_SLEEPRQ          (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  80#define BLK_TA_REQUEUE          (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
  81#define BLK_TA_ISSUE            (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
  82#define BLK_TA_COMPLETE         (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
  83#define BLK_TA_PLUG             (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
  84#define BLK_TA_UNPLUG_IO        (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
  85#define BLK_TA_UNPLUG_TIMER     (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
  86#define BLK_TA_INSERT           (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
  87#define BLK_TA_SPLIT            (__BLK_TA_SPLIT)
  88#define BLK_TA_BOUNCE           (__BLK_TA_BOUNCE)
  89#define BLK_TA_REMAP            (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
  90#define BLK_TA_ABORT            (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
  91#define BLK_TA_DRV_DATA (__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))
  92
  93#define BLK_TN_PROCESS          (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
  94#define BLK_TN_TIMESTAMP        (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
  95#define BLK_TN_MESSAGE          (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
  96
  97#define BLK_IO_TRACE_MAGIC      0x65617400
  98#define BLK_IO_TRACE_VERSION    0x07
  99
 100/*
 101 * The trace itself
 102 */
 103struct blk_io_trace {
 104        __u32 magic;            /* MAGIC << 8 | version */
 105        __u32 sequence;         /* event number */
 106        __u64 time;             /* in microseconds */
 107        __u64 sector;           /* disk offset */
 108        __u32 bytes;            /* transfer length */
 109        __u32 action;           /* what happened */
 110        __u32 pid;              /* who did it */
 111        __u32 device;           /* device number */
 112        __u32 cpu;              /* on what cpu did it happen */
 113        __u16 error;            /* completion error */
 114        __u16 pdu_len;          /* length of data after this trace */
 115};
 116
 117/*
 118 * The remap event
 119 */
 120struct blk_io_trace_remap {
 121        __be32 device_from;
 122        __be32 device_to;
 123        __be64 sector_from;
 124};
 125
 126enum {
 127        Blktrace_setup = 1,
 128        Blktrace_running,
 129        Blktrace_stopped,
 130};
 131
 132#define BLKTRACE_BDEV_SIZE      32
 133
 134/*
 135 * User setup structure passed with BLKTRACESTART
 136 */
 137struct blk_user_trace_setup {
 138        char name[BLKTRACE_BDEV_SIZE];  /* output */
 139        __u16 act_mask;                 /* input */
 140        __u32 buf_size;                 /* input */
 141        __u32 buf_nr;                   /* input */
 142        __u64 start_lba;
 143        __u64 end_lba;
 144        __u32 pid;
 145};
 146
 147#ifdef __KERNEL__
 148#if defined(CONFIG_BLK_DEV_IO_TRACE)
 149
 150#include <linux/sysfs.h>
 151
 152struct blk_trace {
 153        int trace_state;
 154        struct rchan *rchan;
 155        unsigned long __percpu *sequence;
 156        unsigned char __percpu *msg_data;
 157        u16 act_mask;
 158        u64 start_lba;
 159        u64 end_lba;
 160        u32 pid;
 161        u32 dev;
 162        struct dentry *dir;
 163        struct dentry *dropped_file;
 164        struct dentry *msg_file;
 165        atomic_t dropped;
 166};
 167
 168extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 169extern void blk_trace_shutdown(struct request_queue *);
 170extern int do_blk_trace_setup(struct request_queue *q, char *name,
 171                              dev_t dev, struct block_device *bdev,
 172                              struct blk_user_trace_setup *buts);
 173extern __printf(2, 3)
 174void __trace_note_message(struct blk_trace *, const char *fmt, ...);
 175
 176/**
 177 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
 178 * @q:          queue the io is for
 179 * @fmt:        format to print message in
 180 * args...      Variable argument list for format
 181 *
 182 * Description:
 183 *     Records a (simple) message onto the blktrace stream.
 184 *
 185 *     NOTE: BLK_TN_MAX_MSG characters are output at most.
 186 *     NOTE: Can not use 'static inline' due to presence of var args...
 187 *
 188 **/
 189#define blk_add_trace_msg(q, fmt, ...)                                  \
 190        do {                                                            \
 191                struct blk_trace *bt = (q)->blk_trace;                  \
 192                if (unlikely(bt))                                       \
 193                        __trace_note_message(bt, fmt, ##__VA_ARGS__);   \
 194        } while (0)
 195#define BLK_TN_MAX_MSG          128
 196
 197extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
 198                                void *data, size_t len);
 199extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 200                           struct block_device *bdev,
 201                           char __user *arg);
 202extern int blk_trace_startstop(struct request_queue *q, int start);
 203extern int blk_trace_remove(struct request_queue *q);
 204extern void blk_trace_remove_sysfs(struct device *dev);
 205extern int blk_trace_init_sysfs(struct device *dev);
 206
 207extern struct attribute_group blk_trace_attr_group;
 208
 209#else /* !CONFIG_BLK_DEV_IO_TRACE */
 210# define blk_trace_ioctl(bdev, cmd, arg)                (-ENOTTY)
 211# define blk_trace_shutdown(q)                          do { } while (0)
 212# define do_blk_trace_setup(q, name, dev, bdev, buts)   (-ENOTTY)
 213# define blk_add_driver_data(q, rq, data, len)          do {} while (0)
 214# define blk_trace_setup(q, name, dev, bdev, arg)       (-ENOTTY)
 215# define blk_trace_startstop(q, start)                  (-ENOTTY)
 216# define blk_trace_remove(q)                            (-ENOTTY)
 217# define blk_add_trace_msg(q, fmt, ...)                 do { } while (0)
 218# define blk_trace_remove_sysfs(dev)                    do { } while (0)
 219static inline int blk_trace_init_sysfs(struct device *dev)
 220{
 221        return 0;
 222}
 223
 224#endif /* CONFIG_BLK_DEV_IO_TRACE */
 225
 226#ifdef CONFIG_COMPAT
 227
 228struct compat_blk_user_trace_setup {
 229        char name[32];
 230        u16 act_mask;
 231        u32 buf_size;
 232        u32 buf_nr;
 233        compat_u64 start_lba;
 234        compat_u64 end_lba;
 235        u32 pid;
 236};
 237#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
 238
 239#endif
 240
 241#if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
 242
 243static inline int blk_cmd_buf_len(struct request *rq)
 244{
 245        return (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? rq->cmd_len * 3 : 1;
 246}
 247
 248extern void blk_dump_cmd(char *buf, struct request *rq);
 249extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
 250
 251#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
 252
 253#endif /* __KERNEL__ */
 254#endif
 255