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 void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 164 extern int do_blk_trace_setup(struct request_queue *q,
 165         char *name, dev_t dev, struct blk_user_trace_setup *buts);
 166 extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
 167
 168 /**
 169  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
 170  * @q:          queue the io is for
 171  * @fmt:        format to print message in
 172  * args...      Variable argument list for format
 173  *
 174  * Description:
 175  *     Records a (simple) message onto the blktrace stream.
 176  *
 177  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
 178  *     NOTE: Can not use 'static inline' due to presence of var args...
 179  *
 180  **/
 181 #define blk_add_trace_msg(q, fmt, ...)                                  \
 182         do {                                                            \
 183                 struct blk_trace *bt = (q)->blk_trace;                  \
 184                 if (unlikely(bt))                                       \
 185                         __trace_note_message(bt, fmt, ##__VA_ARGS__);   \
 186         } while (0)
 187 #define BLK_TN_MAX_MSG          128
 188
 189 /**
 190  * blk_add_trace_rq - Add a trace for a request oriented action
 191  * @q:          queue the io is for
 192  * @rq:         the source request
 193  * @what:       the action
 194  *
 195  * Description:
 196  *     Records an action against a request. Will log the bio offset + size.
 197  *
 198  **/
 199 static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 200                                     u32 what)
 201 {
 202         struct blk_trace *bt = q->blk_trace;
 203         int rw = rq->cmd_flags & 0x03;
 204
 205         if (likely(!bt))
 206                 return;
 207
 208         if (blk_discard_rq(rq))
 209                 rw |= (1 << BIO_RW_DISCARD);
 210
 211         if (blk_pc_request(rq)) {
 212                 what |= BLK_TC_ACT(BLK_TC_PC);
 213                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 214         } else  {
 215                 what |= BLK_TC_ACT(BLK_TC_FS);
 216                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 217         }
 218 }
 219
 220 /**
 221  * blk_add_trace_bio - Add a trace for a bio oriented action
 222  * @q:          queue the io is for
 223  * @bio:        the source bio
 224  * @what:       the action
 225  *
 226  * Description:
 227  *     Records an action against a bio. Will log the bio offset + size.
 228  *
 229  **/
 230 static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 231                                      u32 what)
 232 {
 233         struct blk_trace *bt = q->blk_trace;
 234
 235         if (likely(!bt))
 236                 return;
 237
 238         __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 239 }
 240
 241 /**
 242  * blk_add_trace_generic - Add a trace for a generic action
 243  * @q:          queue the io is for
 244  * @bio:        the source bio
 245  * @rw:         the data direction
 246  * @what:       the action
 247  *
 248  * Description:
 249  *     Records a simple trace
 250  *
 251  **/
 252 static inline void blk_add_trace_generic(struct request_queue *q,
 253                                          struct bio *bio, int rw, u32 what)
 254 {
 255         struct blk_trace *bt = q->blk_trace;
 256
 257         if (likely(!bt))
 258                 return;
 259
 260         if (bio)
 261                 blk_add_trace_bio(q, bio, what);
 262         else
 263                 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 264 }
 265
 266 /**
 267  * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
 268  * @q:          queue the io is for
 269  * @what:       the action
 270  * @bio:        the source bio
 271  * @pdu:        the integer payload
 272  *
 273  * Description:
 274  *     Adds a trace with some integer payload. This might be an unplug
 275  *     option given as the action, with the depth at unplug time given
 276  *     as the payload
 277  *
 278  **/
 279 static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
 280                                          struct bio *bio, unsigned int pdu)
 281 {
 282         struct blk_trace *bt = q->blk_trace;
 283         __be64 rpdu = cpu_to_be64(pdu);
 284
 285         if (likely(!bt))
 286                 return;
 287
 288         if (bio)
 289                 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
 290         else
 291                 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
 292 }
 293
 294 /**
 295  * blk_add_trace_remap - Add a trace for a remap operation
 296  * @q:          queue the io is for
 297  * @bio:        the source bio
 298  * @dev:        target device
 299  * @from:       source sector
 300  * @to:         target sector
 301  *
 302  * Description:
 303  *     Device mapper or raid target sometimes need to split a bio because
 304  *     it spans a stripe (or similar). Add a trace for that action.
 305  *
 306  **/
 307 static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 308                                        dev_t dev, sector_t from, sector_t to)
 309 {
 310         struct blk_trace *bt = q->blk_trace;
 311         struct blk_io_trace_remap r;
 312
 313         if (likely(!bt))
 314                 return;
 315
 316         r.device = cpu_to_be32(dev);
 317         r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
 318         r.sector = cpu_to_be64(to);
 319
 320         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 321 }
 322
 323 /**
 324  * blk_add_driver_data - Add binary message with driver-specific data
 325  * @q:          queue the io is for
 326  * @rq:         io request
 327  * @data:       driver-specific data
 328  * @len:        length of driver-specific data
 329  *
 330  * Description:
 331  *     Some drivers might want to write driver-specific data per request.
 332  *
 333  **/
 334 static inline void blk_add_driver_data(struct request_queue *q,
 335                                        struct request *rq,
 336                                        void *data, size_t len)
 337 {
 338         struct blk_trace *bt = q->blk_trace;
 339
 340         if (likely(!bt))
 341                 return;
 342
 343         if (blk_pc_request(rq))
 344                 __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
 345                                 rq->errors, len, data);
 346         else
 347                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
 348                                 0, BLK_TA_DRV_DATA, rq->errors, len, data);
 349 }
 350
 351 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 352                            char __user *arg);
 353 extern int blk_trace_startstop(struct request_queue *q, int start);
 354 extern int blk_trace_remove(struct request_queue *q);
 355
 356 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 357 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 358 #define blk_trace_shutdown(q)                   do { } while (0)
 359 #define blk_add_trace_rq(q, rq, what)           do { } while (0)
 360 #define blk_add_trace_bio(q, rq, what)          do { } while (0)
 361 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 362 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 363 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
 364 #define blk_add_driver_data(q, rq, data, len)   do {} while (0)
 365 #define do_blk_trace_setup(q, name, dev, buts)  (-ENOTTY)
 366 #define blk_trace_setup(q, name, dev, arg)      (-ENOTTY)
 367 #define blk_trace_startstop(q, start)           (-ENOTTY)
 368 #define blk_trace_remove(q)                     (-ENOTTY)
 369 #define blk_add_trace_msg(q, fmt, ...)          do { } while (0)
 370
 371 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 372 #endif /* __KERNEL__ */
 373 #endif