kernel/blk-trace-2.6.13-git-E0

   1 diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt
   2 diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
   3 --- a/drivers/block/Kconfig
   4 +++ b/drivers/block/Kconfig
   5 @@ -419,6 +419,14 @@ config LBD
   6           your machine, or if you want to have a raid or loopback device
   7           bigger than 2TB.  Otherwise say N.
   8
   9 +config BLK_DEV_IO_TRACE
  10 +       bool "Support for tracing block io actions"
  11 +       select RELAYFS_FS
  12 +       help
  13 +         Say Y here, if you want to be able to trace the block layer actions
  14 +         on a given queue.
  15 +
  16 +
  17  config CDROM_PKTCDVD
  18         tristate "Packet writing on CD/DVD media"
  19         depends on !UML
  20 diff --git a/drivers/block/Makefile b/drivers/block/Makefile
  21 --- a/drivers/block/Makefile
  22 +++ b/drivers/block/Makefile
  23 @@ -45,3 +45,5 @@ obj-$(CONFIG_VIODASD)         += viodasd.o
  24  obj-$(CONFIG_BLK_DEV_SX8)      += sx8.o
  25  obj-$(CONFIG_BLK_DEV_UB)       += ub.o
  26
  27 +obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
  28 +
  29 diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
  30 --- a/drivers/block/elevator.c
  31 +++ b/drivers/block/elevator.c
  32 @@ -34,6 +34,7 @@
  33  #include <linux/slab.h>
  34  #include <linux/init.h>
  35  #include <linux/compiler.h>
  36 +#include <linux/blktrace.h>
  37
  38  #include <asm/uaccess.h>
  39
  40 @@ -371,6 +372,9 @@ struct request *elv_next_request(request
  41         int ret;
  42
  43         while ((rq = __elv_next_request(q)) != NULL) {
  44 +
  45 +               blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
  46 +
  47                 /*
  48                  * just mark as started even if we don't start it, a request
  49                  * that has been delayed should not be passed by new incoming
  50 diff --git a/drivers/block/ioctl.c b/drivers/block/ioctl.c
  51 --- a/drivers/block/ioctl.c
  52 +++ b/drivers/block/ioctl.c
  53 @@ -4,6 +4,7 @@
  54  #include <linux/backing-dev.h>
  55  #include <linux/buffer_head.h>
  56  #include <linux/smp_lock.h>
  57 +#include <linux/blktrace.h>
  58  #include <asm/uaccess.h>
  59
  60  static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
  61 @@ -188,6 +189,10 @@ static int blkdev_locked_ioctl(struct fi
  62                 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
  63         case BLKGETSIZE64:
  64                 return put_u64(arg, bdev->bd_inode->i_size);
  65 +       case BLKSTARTTRACE:
  66 +               return blk_start_trace(bdev, (char __user *) arg);
  67 +       case BLKSTOPTRACE:
  68 +               return blk_stop_trace(bdev);
  69         }
  70         return -ENOIOCTLCMD;
  71  }
  72 diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
  73 --- a/drivers/block/ll_rw_blk.c
  74 +++ b/drivers/block/ll_rw_blk.c
  75 @@ -29,6 +29,7 @@
  76  #include <linux/swap.h>
  77  #include <linux/writeback.h>
  78  #include <linux/blkdev.h>
  79 +#include <linux/blktrace.h>
  80
  81  /*
  82   * for max sense size
  83 @@ -1624,6 +1625,11 @@ void blk_cleanup_queue(request_queue_t *
  84         if (q->queue_tags)
  85                 __blk_queue_free_tags(q);
  86
  87 +       if (q->blk_trace) {
  88 +               blk_cleanup_trace(q->blk_trace);
  89 +               q->blk_trace = NULL;
  90 +       }
  91 +
  92         blk_queue_ordered(q, QUEUE_ORDERED_NONE);
  93
  94         kmem_cache_free(requestq_cachep, q);
  95 @@ -1970,6 +1976,8 @@ rq_starved:
  96
  97         rq_init(q, rq);
  98         rq->rl = rl;
  99 +
 100 +       blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
 101  out:
 102         return rq;
 103  }
 104 @@ -1998,6 +2006,8 @@ static struct request *get_request_wait(
 105                 if (!rq) {
 106                         struct io_context *ioc;
 107
 108 +                       blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
 109 +
 110                         __generic_unplug_device(q);
 111                         spin_unlock_irq(q->queue_lock);
 112                         io_schedule();
 113 @@ -2051,6 +2061,8 @@ EXPORT_SYMBOL(blk_get_request);
 114   */
 115  void blk_requeue_request(request_queue_t *q, struct request *rq)
 116  {
 117 +       blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
 118 +
 119         if (blk_rq_tagged(rq))
 120                 blk_queue_end_tag(q, rq);
 121
 122 @@ -2714,6 +2726,8 @@ static int __make_request(request_queue_
 123                         if (!q->back_merge_fn(q, req, bio))
 124                                 break;
 125
 126 +                       blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
 127 +
 128                         req->biotail->bi_next = bio;
 129                         req->biotail = bio;
 130                         req->nr_sectors = req->hard_nr_sectors += nr_sectors;
 131 @@ -2729,6 +2743,8 @@ static int __make_request(request_queue_
 132                         if (!q->front_merge_fn(q, req, bio))
 133                                 break;
 134
 135 +                       blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
 136 +
 137                         bio->bi_next = req->bio;
 138                         req->bio = bio;
 139
 140 @@ -2794,6 +2810,8 @@ get_rq:
 141         req->rq_disk = bio->bi_bdev->bd_disk;
 142         req->start_time = jiffies;
 143
 144 +       blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
 145 +
 146         spin_lock_irq(q->queue_lock);
 147         if (elv_queue_empty(q))
 148                 blk_plug_device(q);
 149 @@ -3030,6 +3048,10 @@ end_io:
 150                 blk_partition_remap(bio);
 151
 152                 ret = q->make_request_fn(q, bio);
 153 +
 154 +               if (ret)
 155 +                       blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
 156 +
 157         } while (ret);
 158  }
 159
 160 @@ -3148,6 +3170,8 @@ static int __end_that_request_first(stru
 161         int total_bytes, bio_nbytes, error, next_idx = 0;
 162         struct bio *bio;
 163
 164 +       blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
 165 +
 166         /*
 167          * extend uptodate bool to allow < 0 value to be direct io error
 168          */
 169 diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
 170 --- a/include/linux/blkdev.h
 171 +++ b/include/linux/blkdev.h
 172 @@ -22,6 +22,7 @@ typedef struct request_queue request_que
 173  struct elevator_queue;
 174  typedef struct elevator_queue elevator_t;
 175  struct request_pm_state;
 176 +struct blk_trace;
 177
 178  #define BLKDEV_MIN_RQ  4
 179  #define BLKDEV_MAX_RQ  128     /* Default maximum */
 180 @@ -412,6 +413,8 @@ struct request_queue
 181          */
 182         struct request          *flush_rq;
 183         unsigned char           ordered;
 184 +
 185 +       struct blk_trace        *blk_trace;
 186  };
 187
 188  enum {
 189 diff --git a/include/linux/fs.h b/include/linux/fs.h
 190 --- a/include/linux/fs.h
 191 +++ b/include/linux/fs.h
 192 @@ -195,6 +195,8 @@ extern int dir_notify_enable;
 193  #define BLKBSZGET  _IOR(0x12,112,size_t)
 194  #define BLKBSZSET  _IOW(0x12,113,size_t)
 195  #define BLKGETSIZE64 _IOR(0x12,114,size_t)     /* return device size in bytes (u64 *arg) */
 196 +#define BLKSTARTTRACE _IOWR(0x12,115,struct blk_user_trace_setup)
 197 +#define BLKSTOPTRACE _IO(0x12,116)
 198
 199  #define BMAP_IOCTL 1           /* obsolete - kept for compatibility */
 200  #define FIBMAP    _IO(0x00,1)  /* bmap access */
 201 --- /dev/null   2005-09-03 12:52:15.000000000 +0200
 202 +++ linux-2.6/drivers/block/blktrace.c  2005-09-08 08:33:20.000000000 +0200
 203 @@ -0,0 +1,222 @@
 204 +#include <linux/config.h>
 205 +#include <linux/kernel.h>
 206 +#include <linux/blkdev.h>
 207 +#include <linux/blktrace.h>
 208 +#include <linux/percpu.h>
 209 +#include <linux/init.h>
 210 +#include <asm/uaccess.h>
 211 +
 212 +static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
 213 +
 214 +void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 215 +                    int rw, u32 what, int error, int pdu_len, char *pdu_data)
 216 +{
 217 +       struct blk_io_trace t;
 218 +       unsigned long flags;
 219 +       int cpu;
 220 +
 221 +       if (rw & (1 << BIO_RW_BARRIER))
 222 +               what |= BLK_TC_ACT(BLK_TC_BARRIER);
 223 +       if (rw & (1 << BIO_RW_SYNC))
 224 +               what |= BLK_TC_ACT(BLK_TC_SYNC);
 225 +
 226 +       if (rw & WRITE)
 227 +               what |= BLK_TC_ACT(BLK_TC_WRITE);
 228 +       else
 229 +               what |= BLK_TC_ACT(BLK_TC_READ);
 230 +
 231 +       if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
 232 +               return;
 233 +
 234 +       t.magic         = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
 235 +       t.sequence      = atomic_add_return(1, &bt->sequence);
 236 +
 237 +       cpu = get_cpu();
 238 +       t.cpu           = cpu;
 239 +       t.time          = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
 240 +       put_cpu();
 241 +
 242 +       t.sector        = sector;
 243 +       t.bytes         = bytes;
 244 +       t.action        = what;
 245 +       t.error         = error;
 246 +       t.pdu_len       = pdu_len;
 247 +
 248 +       t.pid           = current->pid;
 249 +       memcpy(t.comm, current->comm, sizeof(t.comm));
 250 +
 251 +       local_irq_save(flags);
 252 +       __relay_write(bt->rchan, &t, sizeof(t));
 253 +       if (pdu_len)
 254 +               __relay_write(bt->rchan, pdu_data, pdu_len);
 255 +       local_irq_restore(flags);
 256 +}
 257 +
 258 +static struct dentry *blk_tree_root;
 259 +static DECLARE_MUTEX(blk_tree_mutex);
 260 +
 261 +static inline void blk_remove_root(void)
 262 +{
 263 +       if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY)
 264 +               blk_tree_root = NULL;
 265 +}
 266 +
 267 +static void blk_remove_tree(struct dentry *dir)
 268 +{
 269 +       down(&blk_tree_mutex);
 270 +       relayfs_remove_dir(dir);
 271 +       blk_remove_root();
 272 +       up(&blk_tree_mutex);
 273 +}
 274 +
 275 +static struct dentry *blk_create_tree(const char *blk_name)
 276 +{
 277 +       struct dentry *dir = NULL;
 278 +
 279 +       down(&blk_tree_mutex);
 280 +
 281 +       if (!blk_tree_root) {
 282 +               blk_tree_root = relayfs_create_dir("block", NULL);
 283 +               if (!blk_tree_root)
 284 +                       goto err;
 285 +       }
 286 +
 287 +       dir = relayfs_create_dir(blk_name, blk_tree_root);
 288 +       if (!dir)
 289 +               blk_remove_root();
 290 +
 291 +err:
 292 +       up(&blk_tree_mutex);
 293 +       return dir;
 294 +}
 295 +
 296 +void blk_cleanup_trace(struct blk_trace *bt)
 297 +{
 298 +       relay_close(bt->rchan);
 299 +       blk_remove_tree(bt->dir);
 300 +       kfree(bt);
 301 +}
 302 +
 303 +int blk_stop_trace(struct block_device *bdev)
 304 +{
 305 +       request_queue_t *q = bdev_get_queue(bdev);
 306 +       struct blk_trace *bt = NULL;
 307 +       int ret = -EINVAL;
 308 +
 309 +       if (!q)
 310 +               return -ENXIO;
 311 +
 312 +       down(&bdev->bd_sem);
 313 +
 314 +       if (q->blk_trace) {
 315 +               bt = q->blk_trace;
 316 +               q->blk_trace = NULL;
 317 +               ret = 0;
 318 +       }
 319 +
 320 +       up(&bdev->bd_sem);
 321 +
 322 +       if (bt)
 323 +               blk_cleanup_trace(bt);
 324 +
 325 +       return ret;
 326 +}
 327 +
 328 +int blk_start_trace(struct block_device *bdev, char __user *arg)
 329 +{
 330 +       request_queue_t *q = bdev_get_queue(bdev);
 331 +       struct blk_user_trace_setup buts;
 332 +       struct blk_trace *bt = NULL;
 333 +       struct dentry *dir = NULL;
 334 +       char b[BDEVNAME_SIZE];
 335 +       int ret;
 336 +
 337 +       if (!q)
 338 +               return -ENXIO;
 339 +
 340 +       if (copy_from_user(&buts, arg, sizeof(buts)))
 341 +               return -EFAULT;
 342 +
 343 +       if (!buts.buf_size || !buts.buf_nr)
 344 +               return -EINVAL;
 345 +
 346 +       strcpy(buts.name, bdevname(bdev, b));
 347 +
 348 +       if (copy_to_user(arg, &buts, sizeof(buts)))
 349 +               return -EFAULT;
 350 +
 351 +       down(&bdev->bd_sem);
 352 +       ret = -EBUSY;
 353 +       if (q->blk_trace)
 354 +               goto err;
 355 +
 356 +       ret = -ENOMEM;
 357 +       bt = kmalloc(sizeof(*bt), GFP_KERNEL);
 358 +       if (!bt)
 359 +               goto err;
 360 +
 361 +       ret = -ENOENT;
 362 +       dir = blk_create_tree(bdevname(bdev, b));
 363 +       if (!dir)
 364 +               goto err;
 365 +
 366 +       bt->dir = dir;
 367 +       atomic_set(&bt->sequence, 0);
 368 +
 369 +       ret = -EIO;
 370 +       bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, NULL);
 371 +       if (!bt->rchan)
 372 +               goto err;
 373 +
 374 +       bt->act_mask = buts.act_mask;
 375 +       if (!bt->act_mask)
 376 +               bt->act_mask = (u16) -1;
 377 +
 378 +       q->blk_trace = bt;
 379 +       up(&bdev->bd_sem);
 380 +       return 0;
 381 +err:
 382 +       up(&bdev->bd_sem);
 383 +       if (dir)
 384 +               blk_remove_tree(dir);
 385 +       if (bt)
 386 +               kfree(bt);
 387 +       return ret;
 388 +}
 389 +
 390 +static void blk_trace_check_cpu_time(void *data)
 391 +{
 392 +       unsigned long long a, b, *t;
 393 +       struct timeval tv;
 394 +       int cpu = get_cpu();
 395 +
 396 +       t = &per_cpu(blk_trace_cpu_offset, cpu);
 397 +
 398 +       a = sched_clock();
 399 +       do_gettimeofday(&tv);
 400 +       b = sched_clock();
 401 +
 402 +       *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 403 +       *t -= (a + b) / 2;
 404 +       put_cpu();
 405 +}
 406 +
 407 +static int blk_trace_calibrate_offsets(void)
 408 +{
 409 +       unsigned long flags;
 410 +
 411 +       smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1);
 412 +       local_irq_save(flags);
 413 +       blk_trace_check_cpu_time(NULL);
 414 +       local_irq_restore(flags);
 415 +
 416 +       return 0;
 417 +}
 418 +
 419 +static __init int blk_trace_init(void)
 420 +{
 421 +       return blk_trace_calibrate_offsets();
 422 +}
 423 +
 424 +module_init(blk_trace_init);
 425 +
 426 --- /dev/null   2005-09-03 12:52:15.000000000 +0200
 427 +++ linux-2.6/include/linux/blktrace.h  2005-09-08 08:33:20.000000000 +0200
 428 @@ -0,0 +1,150 @@
 429 +#ifndef BLKTRACE_H
 430 +#define BLKTRACE_H
 431 +
 432 +#include <linux/config.h>
 433 +#include <linux/blkdev.h>
 434 +#include <linux/relayfs_fs.h>
 435 +
 436 +/*
 437 + * Trace categories
 438 + */
 439 +enum {
 440 +       BLK_TC_READ     = 1 << 0,       /* reads */
 441 +       BLK_TC_WRITE    = 1 << 1,       /* writes */
 442 +       BLK_TC_BARRIER  = 1 << 2,       /* barrier */
 443 +       BLK_TC_SYNC     = 1 << 3,       /* barrier */
 444 +       BLK_TC_QUEUE    = 1 << 4,       /* queueing/merging */
 445 +       BLK_TC_REQUEUE  = 1 << 5,       /* requeueing */
 446 +       BLK_TC_ISSUE    = 1 << 6,       /* issue */
 447 +       BLK_TC_COMPLETE = 1 << 7,       /* completions */
 448 +       BLK_TC_FS       = 1 << 8,       /* fs requests */
 449 +       BLK_TC_PC       = 1 << 9,       /* pc requests */
 450 +
 451 +       BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
 452 +};
 453 +
 454 +#define BLK_TC_SHIFT           (16)
 455 +#define BLK_TC_ACT(act)                ((act) << BLK_TC_SHIFT)
 456 +
 457 +/*
 458 + * Basic trace actions
 459 + */
 460 +enum {
 461 +       __BLK_TA_QUEUE = 1,             /* queued */
 462 +       __BLK_TA_BACKMERGE,             /* back merged to existing rq */
 463 +       __BLK_TA_FRONTMERGE,            /* front merge to existing rq */
 464 +       __BLK_TA_GETRQ,                 /* allocated new request */
 465 +       __BLK_TA_SLEEPRQ,               /* sleeping on rq allocation */
 466 +       __BLK_TA_REQUEUE,               /* request requeued */
 467 +       __BLK_TA_ISSUE,                 /* sent to driver */
 468 +       __BLK_TA_COMPLETE,              /* completed by driver */
 469 +};
 470 +
 471 +/*
 472 + * Trace actions in full. Additionally, read or write is masked
 473 + */
 474 +#define BLK_TA_QUEUE           (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
 475 +#define BLK_TA_BACKMERGE       (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
 476 +#define BLK_TA_FRONTMERGE      (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
 477 +#define        BLK_TA_GETRQ            (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
 478 +#define        BLK_TA_SLEEPRQ          (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
 479 +#define        BLK_TA_REQUEUE          (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
 480 +#define BLK_TA_ISSUE           (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
 481 +#define BLK_TA_COMPLETE                (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
 482 +
 483 +#define BLK_IO_TRACE_MAGIC     0x65617400
 484 +#define BLK_IO_TRACE_VERSION   0x04
 485 +
 486 +/*
 487 + * The trace itself
 488 + */
 489 +struct blk_io_trace {
 490 +       u32 magic;              /* MAGIC << 8 | version */
 491 +       u32 sequence;           /* event number */
 492 +       u64 time;               /* in microseconds */
 493 +       u64 sector;             /* disk offset */
 494 +       u32 bytes;              /* transfer length */
 495 +       u32 action;             /* what happened */
 496 +       u32 pid;                /* who did it */
 497 +       u32 cpu;                /* on what cpu did it happen */
 498 +       u16 error;              /* completion error */
 499 +       u16 pdu_len;            /* length of data after this trace */
 500 +       char comm[16];          /* task command name (TASK_COMM_LEN) */
 501 +};
 502 +
 503 +struct blk_trace {
 504 +       struct dentry *dir;
 505 +       struct rchan *rchan;
 506 +       atomic_t sequence;
 507 +       u16 act_mask;
 508 +};
 509 +
 510 +/*
 511 + * User setup structure passed with BLKSTARTTRACE
 512 + */
 513 +struct blk_user_trace_setup {
 514 +       char name[BDEVNAME_SIZE];       /* output */
 515 +       u16 act_mask;                   /* input */
 516 +       u32 buf_size;                   /* input */
 517 +       u32 buf_nr;                     /* input */
 518 +};
 519 +
 520 +#if defined(CONFIG_BLK_DEV_IO_TRACE)
 521 +extern int blk_start_trace(struct block_device *, char __user *);
 522 +extern int blk_stop_trace(struct block_device *);
 523 +extern void blk_cleanup_trace(struct blk_trace *);
 524 +extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, char *);
 525 +
 526 +static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 527 +                                   u32 what)
 528 +{
 529 +       struct blk_trace *bt = q->blk_trace;
 530 +       int rw = rq->flags & 0x07;
 531 +
 532 +       if (likely(!bt))
 533 +               return;
 534 +
 535 +       if (blk_pc_request(rq)) {
 536 +               what |= BLK_TC_ACT(BLK_TC_PC);
 537 +               __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 538 +       } else  {
 539 +               what |= BLK_TC_ACT(BLK_TC_FS);
 540 +               __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 541 +       }
 542 +}
 543 +
 544 +static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 545 +                                    u32 what)
 546 +{
 547 +       struct blk_trace *bt = q->blk_trace;
 548 +
 549 +       if (likely(!bt))
 550 +               return;
 551 +
 552 +       __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 553 +}
 554 +
 555 +static inline void blk_add_trace_generic(struct request_queue *q,
 556 +                                        struct bio *bio, int rw, u32 what)
 557 +{
 558 +       struct blk_trace *bt = q->blk_trace;
 559 +
 560 +       if (likely(!bt))
 561 +               return;
 562 +
 563 +       if (bio)
 564 +               blk_add_trace_bio(q, bio, what);
 565 +       else
 566 +               __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 567 +}
 568 +
 569 +#else /* !CONFIG_BLK_DEV_IO_TRACE */
 570 +#define blk_start_trace(bdev, arg)             (-EINVAL)
 571 +#define blk_stop_trace(bdev)                   (-EINVAL)
 572 +#define blk_cleanup_trace(bt)                  do { } while (0)
 573 +#define blk_add_trace_rq(q, rq, what)          do { } while (0)
 574 +#define blk_add_trace_bio(q, rq, what)         do { } while (0)
 575 +#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
 576 +#endif /* CONFIG_BLK_DEV_IO_TRACE */
 577 +
 578 +#endif