include/linux/blktrace_api.h

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