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