1 diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
2 --- a/drivers/block/Kconfig
3 +++ b/drivers/block/Kconfig
4 @@ -419,6 +419,14 @@ config LBD
5 your machine, or if you want to have a raid or loopback device
6 bigger than 2TB. Otherwise say N.
8 +config BLK_DEV_IO_TRACE
9 + bool "Support for tracing block io actions"
12 + Say Y here, if you want to be able to trace the block layer actions
17 tristate "Packet writing on CD/DVD media"
19 diff --git a/drivers/block/Makefile b/drivers/block/Makefile
20 --- a/drivers/block/Makefile
21 +++ b/drivers/block/Makefile
22 @@ -45,3 +45,5 @@ obj-$(CONFIG_VIODASD) += viodasd.o
23 obj-$(CONFIG_BLK_DEV_SX8) += sx8.o
24 obj-$(CONFIG_BLK_DEV_UB) += ub.o
26 +obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
28 diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
29 --- a/drivers/block/elevator.c
30 +++ b/drivers/block/elevator.c
32 #include <linux/slab.h>
33 #include <linux/init.h>
34 #include <linux/compiler.h>
35 +#include <linux/blktrace.h>
37 #include <asm/uaccess.h>
39 @@ -305,6 +306,8 @@ void elv_requeue_request(request_queue_t
40 void __elv_add_request(request_queue_t *q, struct request *rq, int where,
43 + blk_add_trace_rq(q, rq, BLK_TA_INSERT);
46 * barriers implicitly indicate back insertion
48 @@ -371,6 +374,9 @@ struct request *elv_next_request(request
51 while ((rq = __elv_next_request(q)) != NULL) {
53 + blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
56 * just mark as started even if we don't start it, a request
57 * that has been delayed should not be passed by new incoming
58 diff --git a/drivers/block/ioctl.c b/drivers/block/ioctl.c
59 --- a/drivers/block/ioctl.c
60 +++ b/drivers/block/ioctl.c
62 #include <linux/backing-dev.h>
63 #include <linux/buffer_head.h>
64 #include <linux/smp_lock.h>
65 +#include <linux/blktrace.h>
66 #include <asm/uaccess.h>
68 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
69 @@ -188,6 +189,10 @@ static int blkdev_locked_ioctl(struct fi
70 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
72 return put_u64(arg, bdev->bd_inode->i_size);
74 + return blk_start_trace(bdev, (char __user *) arg);
76 + return blk_stop_trace(bdev);
80 diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
81 --- a/drivers/block/ll_rw_blk.c
82 +++ b/drivers/block/ll_rw_blk.c
84 #include <linux/swap.h>
85 #include <linux/writeback.h>
86 #include <linux/blkdev.h>
87 +#include <linux/blktrace.h>
91 @@ -1422,8 +1423,10 @@ void blk_plug_device(request_queue_t *q)
92 if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags))
95 - if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
96 + if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
97 mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
98 + blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
102 EXPORT_SYMBOL(blk_plug_device);
103 @@ -1487,8 +1490,12 @@ static void blk_backing_dev_unplug(struc
105 * devices don't necessarily have an ->unplug_fn defined
108 + if (q->unplug_fn) {
109 + int nrq = q->rq.count[READ] + q->rq.count[WRITE];
111 + blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, nrq);
116 static void blk_unplug_work(void *data)
117 @@ -1501,7 +1508,9 @@ static void blk_unplug_work(void *data)
118 static void blk_unplug_timeout(unsigned long data)
120 request_queue_t *q = (request_queue_t *)data;
121 + int nrq = q->rq.count[READ] + q->rq.count[WRITE];
123 + blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, nrq);
124 kblockd_schedule_work(&q->unplug_work);
127 @@ -1624,6 +1633,11 @@ void blk_cleanup_queue(request_queue_t *
129 __blk_queue_free_tags(q);
131 + if (q->blk_trace) {
132 + blk_cleanup_trace(q->blk_trace);
133 + q->blk_trace = NULL;
136 blk_queue_ordered(q, QUEUE_ORDERED_NONE);
138 kmem_cache_free(requestq_cachep, q);
139 @@ -1970,6 +1984,8 @@ rq_starved:
144 + blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
148 @@ -1998,6 +2014,8 @@ static struct request *get_request_wait(
150 struct io_context *ioc;
152 + blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
154 __generic_unplug_device(q);
155 spin_unlock_irq(q->queue_lock);
157 @@ -2051,6 +2069,8 @@ EXPORT_SYMBOL(blk_get_request);
159 void blk_requeue_request(request_queue_t *q, struct request *rq)
161 + blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
163 if (blk_rq_tagged(rq))
164 blk_queue_end_tag(q, rq);
166 @@ -2714,6 +2734,8 @@ static int __make_request(request_queue_
167 if (!q->back_merge_fn(q, req, bio))
170 + blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
172 req->biotail->bi_next = bio;
174 req->nr_sectors = req->hard_nr_sectors += nr_sectors;
175 @@ -2729,6 +2751,8 @@ static int __make_request(request_queue_
176 if (!q->front_merge_fn(q, req, bio))
179 + blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
181 bio->bi_next = req->bio;
184 @@ -3029,6 +3053,8 @@ end_io:
186 blk_partition_remap(bio);
188 + blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
190 ret = q->make_request_fn(q, bio);
193 @@ -3148,6 +3174,8 @@ static int __end_that_request_first(stru
194 int total_bytes, bio_nbytes, error, next_idx = 0;
197 + blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
200 * extend uptodate bool to allow < 0 value to be direct io error
202 diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
203 --- a/include/linux/blkdev.h
204 +++ b/include/linux/blkdev.h
205 @@ -22,6 +22,7 @@ typedef struct request_queue request_que
206 struct elevator_queue;
207 typedef struct elevator_queue elevator_t;
208 struct request_pm_state;
211 #define BLKDEV_MIN_RQ 4
212 #define BLKDEV_MAX_RQ 128 /* Default maximum */
213 @@ -412,6 +413,8 @@ struct request_queue
215 struct request *flush_rq;
216 unsigned char ordered;
218 + struct blk_trace *blk_trace;
222 diff --git a/include/linux/fs.h b/include/linux/fs.h
223 --- a/include/linux/fs.h
224 +++ b/include/linux/fs.h
225 @@ -196,6 +196,8 @@ extern int dir_notify_enable;
226 #define BLKBSZGET _IOR(0x12,112,size_t)
227 #define BLKBSZSET _IOW(0x12,113,size_t)
228 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
229 +#define BLKSTARTTRACE _IOWR(0x12,115,struct blk_user_trace_setup)
230 +#define BLKSTOPTRACE _IO(0x12,116)
232 #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
233 #define FIBMAP _IO(0x00,1) /* bmap access */
234 --- /dev/null 2004-06-30 22:03:36.000000000 +0200
235 +++ linux-2.6/drivers/block/blktrace.c 2005-09-21 12:19:09.000000000 +0200
237 +#include <linux/config.h>
238 +#include <linux/kernel.h>
239 +#include <linux/blkdev.h>
240 +#include <linux/blktrace.h>
241 +#include <linux/percpu.h>
242 +#include <linux/init.h>
243 +#include <asm/uaccess.h>
245 +static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
247 +void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
248 + int rw, u32 what, int error, int pdu_len, void *pdu_data)
250 + struct blk_io_trace t;
251 + unsigned long flags;
254 + if (rw & (1 << BIO_RW_BARRIER))
255 + what |= BLK_TC_ACT(BLK_TC_BARRIER);
256 + if (rw & (1 << BIO_RW_SYNC))
257 + what |= BLK_TC_ACT(BLK_TC_SYNC);
260 + what |= BLK_TC_ACT(BLK_TC_WRITE);
262 + what |= BLK_TC_ACT(BLK_TC_READ);
264 + if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
267 + t.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
268 + t.sequence = atomic_add_return(1, &bt->sequence);
272 + t.time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
275 + t.device = bt->dev;
280 + t.pdu_len = pdu_len;
282 + t.pid = current->pid;
283 + memcpy(t.comm, current->comm, sizeof(t.comm));
285 + local_irq_save(flags);
286 + __relay_write(bt->rchan, &t, sizeof(t));
288 + __relay_write(bt->rchan, pdu_data, pdu_len);
289 + local_irq_restore(flags);
292 +static struct dentry *blk_tree_root;
293 +static DECLARE_MUTEX(blk_tree_mutex);
295 +static inline void blk_remove_root(void)
297 + if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY)
298 + blk_tree_root = NULL;
301 +static void blk_remove_tree(struct dentry *dir)
303 + down(&blk_tree_mutex);
304 + relayfs_remove_dir(dir);
306 + up(&blk_tree_mutex);
309 +static struct dentry *blk_create_tree(const char *blk_name)
311 + struct dentry *dir = NULL;
313 + down(&blk_tree_mutex);
315 + if (!blk_tree_root) {
316 + blk_tree_root = relayfs_create_dir("block", NULL);
317 + if (!blk_tree_root)
321 + dir = relayfs_create_dir(blk_name, blk_tree_root);
326 + up(&blk_tree_mutex);
330 +void blk_cleanup_trace(struct blk_trace *bt)
332 + relay_close(bt->rchan);
333 + blk_remove_tree(bt->dir);
337 +int blk_stop_trace(struct block_device *bdev)
339 + request_queue_t *q = bdev_get_queue(bdev);
340 + struct blk_trace *bt = NULL;
346 + down(&bdev->bd_sem);
348 + if (q->blk_trace) {
350 + q->blk_trace = NULL;
357 + blk_cleanup_trace(bt);
362 +int blk_start_trace(struct block_device *bdev, char __user *arg)
364 + request_queue_t *q = bdev_get_queue(bdev);
365 + struct blk_user_trace_setup buts;
366 + struct blk_trace *bt = NULL;
367 + struct dentry *dir = NULL;
368 + char b[BDEVNAME_SIZE];
374 + if (copy_from_user(&buts, arg, sizeof(buts)))
377 + if (!buts.buf_size || !buts.buf_nr)
380 + strcpy(buts.name, bdevname(bdev, b));
382 + if (copy_to_user(arg, &buts, sizeof(buts)))
385 + down(&bdev->bd_sem);
391 + bt = kmalloc(sizeof(*bt), GFP_KERNEL);
396 + dir = blk_create_tree(bdevname(bdev, b));
401 + bt->dev = bdev->bd_dev;
402 + atomic_set(&bt->sequence, 0);
405 + bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, NULL);
409 + bt->act_mask = buts.act_mask;
411 + bt->act_mask = (u16) -1;
419 + blk_remove_tree(dir);
425 +static void blk_trace_check_cpu_time(void *data)
427 + unsigned long long a, b, *t;
429 + int cpu = get_cpu();
431 + t = &per_cpu(blk_trace_cpu_offset, cpu);
434 + do_gettimeofday(&tv);
437 + *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
442 +static int blk_trace_calibrate_offsets(void)
444 + unsigned long flags;
446 + smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1);
447 + local_irq_save(flags);
448 + blk_trace_check_cpu_time(NULL);
449 + local_irq_restore(flags);
454 +static __init int blk_trace_init(void)
456 + return blk_trace_calibrate_offsets();
459 +module_init(blk_trace_init);
461 --- /dev/null 2004-06-30 22:03:36.000000000 +0200
462 +++ linux-2.6/include/linux/blktrace.h 2005-09-21 16:22:55.000000000 +0200
467 +#include <linux/config.h>
468 +#include <linux/blkdev.h>
469 +#include <linux/relayfs_fs.h>
475 + BLK_TC_READ = 1 << 0, /* reads */
476 + BLK_TC_WRITE = 1 << 1, /* writes */
477 + BLK_TC_BARRIER = 1 << 2, /* barrier */
478 + BLK_TC_SYNC = 1 << 3, /* barrier */
479 + BLK_TC_QUEUE = 1 << 4, /* queueing/merging */
480 + BLK_TC_REQUEUE = 1 << 5, /* requeueing */
481 + BLK_TC_ISSUE = 1 << 6, /* issue */
482 + BLK_TC_COMPLETE = 1 << 7, /* completions */
483 + BLK_TC_FS = 1 << 8, /* fs requests */
484 + BLK_TC_PC = 1 << 9, /* pc requests */
486 + BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
489 +#define BLK_TC_SHIFT (16)
490 +#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
493 + * Basic trace actions
496 + __BLK_TA_QUEUE = 1, /* queued */
497 + __BLK_TA_BACKMERGE, /* back merged to existing rq */
498 + __BLK_TA_FRONTMERGE, /* front merge to existing rq */
499 + __BLK_TA_GETRQ, /* allocated new request */
500 + __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
501 + __BLK_TA_REQUEUE, /* request requeued */
502 + __BLK_TA_ISSUE, /* sent to driver */
503 + __BLK_TA_COMPLETE, /* completed by driver */
504 + __BLK_TA_PLUG, /* queue was plugged */
505 + __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
506 + __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
507 + __BLK_TA_INSERT, /* insert request */
511 + * Trace actions in full. Additionally, read or write is masked
513 +#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
514 +#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
515 +#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
516 +#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
517 +#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
518 +#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
519 +#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
520 +#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
521 +#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
522 +#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
523 +#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
524 +#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
526 +#define BLK_IO_TRACE_MAGIC 0x65617400
527 +#define BLK_IO_TRACE_VERSION 0x05
532 +struct blk_io_trace {
533 + u32 magic; /* MAGIC << 8 | version */
534 + u32 sequence; /* event number */
535 + u64 time; /* in microseconds */
536 + u64 sector; /* disk offset */
537 + u32 bytes; /* transfer length */
538 + u32 action; /* what happened */
539 + u32 pid; /* who did it */
540 + u32 cpu; /* on what cpu did it happen */
541 + u16 error; /* completion error */
542 + u16 pdu_len; /* length of data after this trace */
543 + u32 device; /* device number */
544 + char comm[16]; /* task command name (TASK_COMM_LEN) */
548 + struct dentry *dir;
549 + struct rchan *rchan;
556 + * User setup structure passed with BLKSTARTTRACE
558 +struct blk_user_trace_setup {
559 + char name[BDEVNAME_SIZE]; /* output */
560 + u16 act_mask; /* input */
561 + u32 buf_size; /* input */
562 + u32 buf_nr; /* input */
565 +#if defined(CONFIG_BLK_DEV_IO_TRACE)
566 +extern int blk_start_trace(struct block_device *, char __user *);
567 +extern int blk_stop_trace(struct block_device *);
568 +extern void blk_cleanup_trace(struct blk_trace *);
569 +extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
571 +static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
574 + struct blk_trace *bt = q->blk_trace;
575 + int rw = rq->flags & 0x07;
580 + if (blk_pc_request(rq)) {
581 + what |= BLK_TC_ACT(BLK_TC_PC);
582 + __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
584 + what |= BLK_TC_ACT(BLK_TC_FS);
585 + __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
589 +static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
592 + struct blk_trace *bt = q->blk_trace;
597 + __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
600 +static inline void blk_add_trace_generic(struct request_queue *q,
601 + struct bio *bio, int rw, u32 what)
603 + struct blk_trace *bt = q->blk_trace;
609 + blk_add_trace_bio(q, bio, what);
611 + __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
614 +static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
617 + struct blk_trace *bt = q->blk_trace;
618 + u64 rpdu = cpu_to_be64(pdu);
623 + __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
626 +#else /* !CONFIG_BLK_DEV_IO_TRACE */
627 +#define blk_start_trace(bdev, arg) (-EINVAL)
628 +#define blk_stop_trace(bdev) (-EINVAL)
629 +#define blk_cleanup_trace(bt) do { } while (0)
630 +#define blk_add_trace_rq(q, rq, what) do { } while (0)
631 +#define blk_add_trace_bio(q, rq, what) do { } while (0)
632 +#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
633 +#define blk_add_trace_pdu_int(q, what, pdul, pdu) do { } while (0)
634 +#endif /* CONFIG_BLK_DEV_IO_TRACE */