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
  28         BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
  29 };
  30
  31 #define BLK_TC_SHIFT            (16)
  32 #define BLK_TC_ACT(act)         ((act) << BLK_TC_SHIFT)
  33
  34 /*
  35  * Basic trace actions
  36  */
  37 enum blktrace_act {
  38         __BLK_TA_QUEUE = 1,             /* queued */
  39         __BLK_TA_BACKMERGE,             /* back merged to existing rq */
  40         __BLK_TA_FRONTMERGE,            /* front merge to existing rq */
  41         __BLK_TA_GETRQ,                 /* allocated new request */
  42         __BLK_TA_SLEEPRQ,               /* sleeping on rq allocation */
  43         __BLK_TA_REQUEUE,               /* request requeued */
  44         __BLK_TA_ISSUE,                 /* sent to driver */
  45         __BLK_TA_COMPLETE,              /* completed by driver */
  46         __BLK_TA_PLUG,                  /* queue was plugged */
  47         __BLK_TA_UNPLUG_IO,             /* queue was unplugged by io */
  48         __BLK_TA_UNPLUG_TIMER,          /* queue was unplugged by timer */
  49         __BLK_TA_INSERT,                /* insert request */
  50         __BLK_TA_SPLIT,                 /* bio was split */
  51         __BLK_TA_BOUNCE,                /* bio was bounced */
  52         __BLK_TA_REMAP,                 /* bio was remapped */
  53         __BLK_TA_ABORT,                 /* request aborted */
  54 };
  55
  56 /*
  57  * Notify events.
  58  */
  59 enum blktrace_notify {
  60         __BLK_TN_PROCESS = 0,           /* establish pid/name mapping */
  61         __BLK_TN_TIMESTAMP,             /* include system clock */
  62         __BLK_TN_MESSAGE,               /* Character string message */
  63 };
  64
  65
  66 /*
  67  * Trace actions in full. Additionally, read or write is masked
  68  */
  69 #define BLK_TA_QUEUE            (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
  70 #define BLK_TA_BACKMERGE        (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  71 #define BLK_TA_FRONTMERGE       (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  72 #define BLK_TA_GETRQ            (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  73 #define BLK_TA_SLEEPRQ          (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  74 #define BLK_TA_REQUEUE          (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
  75 #define BLK_TA_ISSUE            (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
  76 #define BLK_TA_COMPLETE         (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
  77 #define BLK_TA_PLUG             (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
  78 #define BLK_TA_UNPLUG_IO        (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
  79 #define BLK_TA_UNPLUG_TIMER     (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
  80 #define BLK_TA_INSERT           (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
  81 #define BLK_TA_SPLIT            (__BLK_TA_SPLIT)
  82 #define BLK_TA_BOUNCE           (__BLK_TA_BOUNCE)
  83 #define BLK_TA_REMAP            (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
  84 #define BLK_TA_ABORT            (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
  85
  86 #define BLK_TN_PROCESS          (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
  87 #define BLK_TN_TIMESTAMP        (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
  88 #define BLK_TN_MESSAGE          (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
  89
  90 #define BLK_IO_TRACE_MAGIC      0x65617400
  91 #define BLK_IO_TRACE_VERSION    0x07
  92
  93 /*
  94  * The trace itself
  95  */
  96 struct blk_io_trace {
  97         __u32 magic;            /* MAGIC << 8 | version */
  98         __u32 sequence;         /* event number */
  99         __u64 time;             /* in microseconds */
 100         __u64 sector;           /* disk offset */
 101         __u32 bytes;            /* transfer length */
 102         __u32 action;           /* what happened */
 103         __u32 pid;              /* who did it */
 104         __u32 device;           /* device number */
 105         __u32 cpu;              /* on what cpu did it happen */
 106         __u16 error;            /* completion error */
 107         __u16 pdu_len;          /* length of data after this trace */
 108 };
 109
 110 /*
 111  * The remap event
 112  */
 113 struct blk_io_trace_remap {
 114         __be32 device;
 115         __be32 device_from;
 116         __be64 sector;
 117 };
 118
 119 enum {
 120         Blktrace_setup = 1,
 121         Blktrace_running,
 122         Blktrace_stopped,
 123 };
 124
 125 #define BLKTRACE_BDEV_SIZE      32
 126
 127 /*
 128  * User setup structure passed with BLKTRACESTART
 129  */
 130 struct blk_user_trace_setup {
 131         char name[BLKTRACE_BDEV_SIZE];  /* output */
 132         __u16 act_mask;                 /* input */
 133         __u32 buf_size;                 /* input */
 134         __u32 buf_nr;                   /* input */
 135         __u64 start_lba;
 136         __u64 end_lba;
 137         __u32 pid;
 138 };
 139
 140 #ifdef __KERNEL__
 141 #if defined(CONFIG_BLK_DEV_IO_TRACE)
 142 struct blk_trace {
 143         int trace_state;
 144         struct rchan *rchan;
 145         unsigned long *sequence;
 146         unsigned char *msg_data;
 147         u16 act_mask;
 148         u64 start_lba;
 149         u64 end_lba;
 150         u32 pid;
 151         u32 dev;
 152         struct dentry *dir;
 153         struct dentry *dropped_file;
 154         struct dentry *msg_file;
 155         atomic_t dropped;
 156 };
 157
 158 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 159 extern void blk_trace_shutdown(struct request_queue *);
 160 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 161 extern int do_blk_trace_setup(struct request_queue *q,
 162         char *name, dev_t dev, struct blk_user_trace_setup *buts);
 163 extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
 164
 165 /**
 166  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
 167  * @q:          queue the io is for
 168  * @fmt:        format to print message in
 169  * args...      Variable argument list for format
 170  *
 171  * Description:
 172  *     Records a (simple) message onto the blktrace stream.
 173  *
 174  *     NOTE: BLK_TN_MAX_MSG characters are output at most.
 175  *     NOTE: Can not use 'static inline' due to presence of var args...
 176  *
 177  **/
 178 #define blk_add_trace_msg(q, fmt, ...)                                  \
 179         do {                                                            \
 180                 struct blk_trace *bt = (q)->blk_trace;                  \
 181                 if (unlikely(bt))                                       \
 182                         __trace_note_message(bt, fmt, ##__VA_ARGS__);   \
 183         } while (0)
 184 #define BLK_TN_MAX_MSG          128
 185
 186 /**
 187  * blk_add_trace_rq - Add a trace for a request oriented action
 188  * @q:          queue the io is for
 189  * @rq:         the source request
 190  * @what:       the action
 191  *
 192  * Description:
 193  *     Records an action against a request. Will log the bio offset + size.
 194  *
 195  **/
 196 static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 197                                     u32 what)
 198 {
 199         struct blk_trace *bt = q->blk_trace;
 200         int rw = rq->cmd_flags & 0x03;
 201
 202         if (likely(!bt))
 203                 return;
 204
 205         if (blk_discard_rq(rq))
 206                 rw |= (1 << BIO_RW_DISCARD);
 207
 208         if (blk_pc_request(rq)) {
 209                 what |= BLK_TC_ACT(BLK_TC_PC);
 210                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 211         } else  {
 212                 what |= BLK_TC_ACT(BLK_TC_FS);
 213                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 214         }
 215 }
 216
 217 /**
 218  * blk_add_trace_bio - Add a trace for a bio oriented action
 219  * @q:          queue the io is for
 220  * @bio:        the source bio
 221  * @what:       the action
 222  *
 223  * Description:
 224  *     Records an action against a bio. Will log the bio offset + size.
 225  *
 226  **/
 227 static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 228                                      u32 what)
 229 {
 230         struct blk_trace *bt = q->blk_trace;
 231
 232         if (likely(!bt))
 233                 return;
 234
 235         __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 236 }
 237
 238 /**
 239  * blk_add_trace_generic - Add a trace for a generic action
 240  * @q:          queue the io is for
 241  * @bio:        the source bio
 242  * @rw:         the data direction
 243  * @what:       the action
 244  *
 245  * Description:
 246  *     Records a simple trace
 247  *
 248  **/
 249 static inline void blk_add_trace_generic(struct request_queue *q,
 250                                          struct bio *bio, int rw, u32 what)
 251 {
 252         struct blk_trace *bt = q->blk_trace;
 253
 254         if (likely(!bt))
 255                 return;
 256
 257         if (bio)
 258                 blk_add_trace_bio(q, bio, what);
 259         else
 260                 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 261 }
 262
 263 /**
 264  * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
 265  * @q:          queue the io is for
 266  * @what:       the action
 267  * @bio:        the source bio
 268  * @pdu:        the integer payload
 269  *
 270  * Description:
 271  *     Adds a trace with some integer payload. This might be an unplug
 272  *     option given as the action, with the depth at unplug time given
 273  *     as the payload
 274  *
 275  **/
 276 static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
 277                                          struct bio *bio, unsigned int pdu)
 278 {
 279         struct blk_trace *bt = q->blk_trace;
 280         __be64 rpdu = cpu_to_be64(pdu);
 281
 282         if (likely(!bt))
 283                 return;
 284
 285         if (bio)
 286                 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
 287         else
 288                 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
 289 }
 290
 291 /**
 292  * blk_add_trace_remap - Add a trace for a remap operation
 293  * @q:          queue the io is for
 294  * @bio:        the source bio
 295  * @dev:        target device
 296  * @from:       source sector
 297  * @to:         target sector
 298  *
 299  * Description:
 300  *     Device mapper or raid target sometimes need to split a bio because
 301  *     it spans a stripe (or similar). Add a trace for that action.
 302  *
 303  **/
 304 static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 305                                        dev_t dev, sector_t from, sector_t to)
 306 {
 307         struct blk_trace *bt = q->blk_trace;
 308         struct blk_io_trace_remap r;
 309
 310         if (likely(!bt))
 311                 return;
 312
 313         r.device = cpu_to_be32(dev);
 314         r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
 315         r.sector = cpu_to_be64(to);
 316
 317         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 318 }
 319
 320 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 321                            char __user *arg);
 322 extern int blk_trace_startstop(struct request_queue *q, int start);
 323 extern int blk_trace_remove(struct request_queue *q);
 324
 325 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 326 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 327 #define blk_trace_shutdown(q)                   do { } while (0)
 328 #define blk_add_trace_rq(q, rq, what)           do { } while (0)
 329 #define blk_add_trace_bio(q, rq, what)          do { } while (0)
 330 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 331 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 332 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
 333 #define do_blk_trace_setup(q, name, dev, buts)  (-ENOTTY)
 334 #define blk_trace_setup(q, name, dev, arg)      (-ENOTTY)
 335 #define blk_trace_startstop(q, start)           (-ENOTTY)
 336 #define blk_trace_remove(q)                     (-ENOTTY)
 337 #define blk_add_trace_msg(q, fmt, ...)          do { } while (0)
 338
 339 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 340 #endif /* __KERNEL__ */
 341 #endif