include/linux/blktrace_api.h

   1 #ifndef BLKTRACE_H
   2 #define BLKTRACE_H
   3
   4 #include <linux/blkdev.h>
   5 #include <linux/relay.h>
   6
   7 /*
   8  * Trace categories
   9  */
  10 enum blktrace_cat {
  11         BLK_TC_READ     = 1 << 0,       /* reads */
  12         BLK_TC_WRITE    = 1 << 1,       /* writes */
  13         BLK_TC_BARRIER  = 1 << 2,       /* barrier */
  14         BLK_TC_SYNC     = 1 << 3,       /* sync IO */
  15         BLK_TC_QUEUE    = 1 << 4,       /* queueing/merging */
  16         BLK_TC_REQUEUE  = 1 << 5,       /* requeueing */
  17         BLK_TC_ISSUE    = 1 << 6,       /* issue */
  18         BLK_TC_COMPLETE = 1 << 7,       /* completions */
  19         BLK_TC_FS       = 1 << 8,       /* fs requests */
  20         BLK_TC_PC       = 1 << 9,       /* pc requests */
  21         BLK_TC_NOTIFY   = 1 << 10,      /* special message */
  22         BLK_TC_AHEAD    = 1 << 11,      /* readahead */
  23         BLK_TC_META     = 1 << 12,      /* metadata */
  24         BLK_TC_DISCARD  = 1 << 13,      /* discard requests */
  25
  26         BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
  27 };
  28
  29 #define BLK_TC_SHIFT            (16)
  30 #define BLK_TC_ACT(act)         ((act) << BLK_TC_SHIFT)
  31
  32 /*
  33  * Basic trace actions
  34  */
  35 enum blktrace_act {
  36         __BLK_TA_QUEUE = 1,             /* queued */
  37         __BLK_TA_BACKMERGE,             /* back merged to existing rq */
  38         __BLK_TA_FRONTMERGE,            /* front merge to existing rq */
  39         __BLK_TA_GETRQ,                 /* allocated new request */
  40         __BLK_TA_SLEEPRQ,               /* sleeping on rq allocation */
  41         __BLK_TA_REQUEUE,               /* request requeued */
  42         __BLK_TA_ISSUE,                 /* sent to driver */
  43         __BLK_TA_COMPLETE,              /* completed by driver */
  44         __BLK_TA_PLUG,                  /* queue was plugged */
  45         __BLK_TA_UNPLUG_IO,             /* queue was unplugged by io */
  46         __BLK_TA_UNPLUG_TIMER,          /* queue was unplugged by timer */
  47         __BLK_TA_INSERT,                /* insert request */
  48         __BLK_TA_SPLIT,                 /* bio was split */
  49         __BLK_TA_BOUNCE,                /* bio was bounced */
  50         __BLK_TA_REMAP,                 /* bio was remapped */
  51         __BLK_TA_ABORT,                 /* request aborted */
  52 };
  53
  54 /*
  55  * Notify events.
  56  */
  57 enum blktrace_notify {
  58         __BLK_TN_PROCESS = 0,           /* establish pid/name mapping */
  59         __BLK_TN_TIMESTAMP,             /* include system clock */
  60         __BLK_TN_MESSAGE,               /* Character string message */
  61 };
  62
  63
  64 /*
  65  * Trace actions in full. Additionally, read or write is masked
  66  */
  67 #define BLK_TA_QUEUE            (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
  68 #define BLK_TA_BACKMERGE        (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  69 #define BLK_TA_FRONTMERGE       (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  70 #define BLK_TA_GETRQ            (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  71 #define BLK_TA_SLEEPRQ          (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  72 #define BLK_TA_REQUEUE          (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
  73 #define BLK_TA_ISSUE            (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
  74 #define BLK_TA_COMPLETE         (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
  75 #define BLK_TA_PLUG             (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
  76 #define BLK_TA_UNPLUG_IO        (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
  77 #define BLK_TA_UNPLUG_TIMER     (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
  78 #define BLK_TA_INSERT           (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
  79 #define BLK_TA_SPLIT            (__BLK_TA_SPLIT)
  80 #define BLK_TA_BOUNCE           (__BLK_TA_BOUNCE)
  81 #define BLK_TA_REMAP            (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
  82 #define BLK_TA_ABORT            (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
  83
  84 #define BLK_TN_PROCESS          (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
  85 #define BLK_TN_TIMESTAMP        (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
  86 #define BLK_TN_MESSAGE          (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
  87
  88 #define BLK_IO_TRACE_MAGIC      0x65617400
  89 #define BLK_IO_TRACE_VERSION    0x07
  90
  91 /*
  92  * The trace itself
  93  */
  94 struct blk_io_trace {
  95         u32 magic;              /* MAGIC << 8 | version */
  96         u32 sequence;           /* event number */
  97         u64 time;               /* in microseconds */
  98         u64 sector;             /* disk offset */
  99         u32 bytes;              /* transfer length */
 100         u32 action;             /* what happened */
 101         u32 pid;                /* who did it */
 102         u32 device;             /* device number */
 103         u32 cpu;                /* on what cpu did it happen */
 104         u16 error;              /* completion error */
 105         u16 pdu_len;            /* length of data after this trace */
 106 };
 107
 108 /*
 109  * The remap event
 110  */
 111 struct blk_io_trace_remap {
 112         __be32 device;
 113         __be32 device_from;
 114         __be64 sector;
 115 };
 116
 117 enum {
 118         Blktrace_setup = 1,
 119         Blktrace_running,
 120         Blktrace_stopped,
 121 };
 122
 123 struct blk_trace {
 124         int trace_state;
 125         struct rchan *rchan;
 126         unsigned long *sequence;
 127         unsigned char *msg_data;
 128         u16 act_mask;
 129         u64 start_lba;
 130         u64 end_lba;
 131         u32 pid;
 132         u32 dev;
 133         struct dentry *dir;
 134         struct dentry *dropped_file;
 135         struct dentry *msg_file;
 136         atomic_t dropped;
 137 };
 138
 139 /*
 140  * User setup structure passed with BLKTRACESTART
 141  */
 142 struct blk_user_trace_setup {
 143         char name[BDEVNAME_SIZE];       /* output */
 144         u16 act_mask;                   /* input */
 145         u32 buf_size;                   /* input */
 146         u32 buf_nr;                     /* input */
 147         u64 start_lba;
 148         u64 end_lba;
 149         u32 pid;
 150 };
 151
 152 #ifdef __KERNEL__
 153 #if defined(CONFIG_BLK_DEV_IO_TRACE)
 154 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 155 extern void blk_trace_shutdown(struct request_queue *);
 156 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 157 extern int do_blk_trace_setup(struct request_queue *q,
 158         char *name, dev_t dev, struct blk_user_trace_setup *buts);
 159 extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
 160
 161 /**
 162  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
 163  * @q:          queue the io is for
 164  * @fmt:        format to print message in
 165  * args...      Variable argument list for format
 166  *
 167  * Description:
 168  *     Records a (simple) message onto the blktrace stream.
 169  *
 170  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
 171  *     NOTE: Can not use 'static inline' due to presence of var args...
 172  *
 173  **/
 174 #define blk_add_trace_msg(q, fmt, ...)                                  \
 175         do {                                                            \
 176                 struct blk_trace *bt = (q)->blk_trace;                  \
 177                 if (unlikely(bt))                                       \
 178                         __trace_note_message(bt, fmt, ##__VA_ARGS__);   \
 179         } while (0)
 180 #define BLK_TN_MAX_MSG          128
 181
 182 /**
 183  * blk_add_trace_rq - Add a trace for a request oriented action
 184  * @q:          queue the io is for
 185  * @rq:         the source request
 186  * @what:       the action
 187  *
 188  * Description:
 189  *     Records an action against a request. Will log the bio offset + size.
 190  *
 191  **/
 192 static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 193                                     u32 what)
 194 {
 195         struct blk_trace *bt = q->blk_trace;
 196         int rw = rq->cmd_flags & 0x03;
 197
 198         if (likely(!bt))
 199                 return;
 200
 201         if (blk_discard_rq(rq))
 202                 rw |= (1 << BIO_RW_DISCARD);
 203
 204         if (blk_pc_request(rq)) {
 205                 what |= BLK_TC_ACT(BLK_TC_PC);
 206                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 207         } else  {
 208                 what |= BLK_TC_ACT(BLK_TC_FS);
 209                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 210         }
 211 }
 212
 213 /**
 214  * blk_add_trace_bio - Add a trace for a bio oriented action
 215  * @q:          queue the io is for
 216  * @bio:        the source bio
 217  * @what:       the action
 218  *
 219  * Description:
 220  *     Records an action against a bio. Will log the bio offset + size.
 221  *
 222  **/
 223 static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 224                                      u32 what)
 225 {
 226         struct blk_trace *bt = q->blk_trace;
 227
 228         if (likely(!bt))
 229                 return;
 230
 231         __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 232 }
 233
 234 /**
 235  * blk_add_trace_generic - Add a trace for a generic action
 236  * @q:          queue the io is for
 237  * @bio:        the source bio
 238  * @rw:         the data direction
 239  * @what:       the action
 240  *
 241  * Description:
 242  *     Records a simple trace
 243  *
 244  **/
 245 static inline void blk_add_trace_generic(struct request_queue *q,
 246                                          struct bio *bio, int rw, u32 what)
 247 {
 248         struct blk_trace *bt = q->blk_trace;
 249
 250         if (likely(!bt))
 251                 return;
 252
 253         if (bio)
 254                 blk_add_trace_bio(q, bio, what);
 255         else
 256                 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 257 }
 258
 259 /**
 260  * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
 261  * @q:          queue the io is for
 262  * @what:       the action
 263  * @bio:        the source bio
 264  * @pdu:        the integer payload
 265  *
 266  * Description:
 267  *     Adds a trace with some integer payload. This might be an unplug
 268  *     option given as the action, with the depth at unplug time given
 269  *     as the payload
 270  *
 271  **/
 272 static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
 273                                          struct bio *bio, unsigned int pdu)
 274 {
 275         struct blk_trace *bt = q->blk_trace;
 276         __be64 rpdu = cpu_to_be64(pdu);
 277
 278         if (likely(!bt))
 279                 return;
 280
 281         if (bio)
 282                 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
 283         else
 284                 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
 285 }
 286
 287 /**
 288  * blk_add_trace_remap - Add a trace for a remap operation
 289  * @q:          queue the io is for
 290  * @bio:        the source bio
 291  * @dev:        target device
 292  * @from:       source sector
 293  * @to:         target sector
 294  *
 295  * Description:
 296  *     Device mapper or raid target sometimes need to split a bio because
 297  *     it spans a stripe (or similar). Add a trace for that action.
 298  *
 299  **/
 300 static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 301                                        dev_t dev, sector_t from, sector_t to)
 302 {
 303         struct blk_trace *bt = q->blk_trace;
 304         struct blk_io_trace_remap r;
 305
 306         if (likely(!bt))
 307                 return;
 308
 309         r.device = cpu_to_be32(dev);
 310         r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
 311         r.sector = cpu_to_be64(to);
 312
 313         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 314 }
 315
 316 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 317                            char __user *arg);
 318 extern int blk_trace_startstop(struct request_queue *q, int start);
 319 extern int blk_trace_remove(struct request_queue *q);
 320
 321 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 322 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 323 #define blk_trace_shutdown(q)                   do { } while (0)
 324 #define blk_add_trace_rq(q, rq, what)           do { } while (0)
 325 #define blk_add_trace_bio(q, rq, what)          do { } while (0)
 326 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 327 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 328 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
 329 #define do_blk_trace_setup(q, name, dev, buts)  (-ENOTTY)
 330 #define blk_trace_setup(q, name, dev, arg)      (-ENOTTY)
 331 #define blk_trace_startstop(q, start)           (-ENOTTY)
 332 #define blk_trace_remove(q)                     (-ENOTTY)
 333 #define blk_add_trace_msg(q, fmt, ...)          do { } while (0)
 334
 335 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 336 #endif /* __KERNEL__ */
 337 #endif