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