diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/Kconfig | 1 | ||||
| -rw-r--r-- | block/blk-core.c | 46 | ||||
| -rw-r--r-- | block/blktrace.c | 332 | ||||
| -rw-r--r-- | block/elevator.c | 12 |
4 files changed, 366 insertions, 25 deletions
diff --git a/block/Kconfig b/block/Kconfig index 1ab7c15..290b219 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -47,6 +47,7 @@ config BLK_DEV_IO_TRACE depends on SYSFS select RELAY select DEBUG_FS + select TRACEPOINTS help Say Y here if you want to be able to trace the block layer actions on a given queue. Tracing allows you to see any traffic happening diff --git a/block/blk-core.c b/block/blk-core.c index c36aa98..561e8a1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -28,9 +28,23 @@ #include <linux/task_io_accounting_ops.h> #include <linux/blktrace_api.h> #include <linux/fault-inject.h> +#include <trace/block.h> #include "blk.h" +DEFINE_TRACE(block_plug); +DEFINE_TRACE(block_unplug_io); +DEFINE_TRACE(block_unplug_timer); +DEFINE_TRACE(block_getrq); +DEFINE_TRACE(block_sleeprq); +DEFINE_TRACE(block_rq_requeue); +DEFINE_TRACE(block_bio_backmerge); +DEFINE_TRACE(block_bio_frontmerge); +DEFINE_TRACE(block_bio_queue); +DEFINE_TRACE(block_rq_complete); +DEFINE_TRACE(block_remap); /* Also used in drivers/md/dm.c */ +EXPORT_TRACEPOINT_SYMBOL_GPL(block_remap); + static int __make_request(struct request_queue *q, struct bio *bio); /* @@ -205,7 +219,7 @@ void blk_plug_device(struct request_queue *q) if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) { mod_timer(&q->unplug_timer, jiffies + q->unplug_delay); - blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG); + trace_block_plug(q); } } EXPORT_SYMBOL(blk_plug_device); @@ -292,9 +306,7 @@ void blk_unplug_work(struct work_struct *work) struct request_queue *q = container_of(work, struct request_queue, unplug_work); - blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, - q->rq.count[READ] + q->rq.count[WRITE]); - + trace_block_unplug_io(q); q->unplug_fn(q); } @@ -302,9 +314,7 @@ void blk_unplug_timeout(unsigned long data) { struct request_queue *q = (struct request_queue *)data; - blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL, - q->rq.count[READ] + q->rq.count[WRITE]); - + trace_block_unplug_timer(q); kblockd_schedule_work(q, &q->unplug_work); } @@ -314,9 +324,7 @@ void blk_unplug(struct request_queue *q) * devices don't necessarily have an ->unplug_fn defined */ if (q->unplug_fn) { - blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, - q->rq.count[READ] + q->rq.count[WRITE]); - + trace_block_unplug_io(q); q->unplug_fn(q); } } @@ -822,7 +830,7 @@ rq_starved: if (ioc_batching(q, ioc)) ioc->nr_batch_requests--; - blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ); + trace_block_getrq(q, bio, rw); out: return rq; } @@ -848,7 +856,7 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags, prepare_to_wait_exclusive(&rl->wait[rw], &wait, TASK_UNINTERRUPTIBLE); - blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); + trace_block_sleeprq(q, bio, rw); __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); @@ -928,7 +936,7 @@ void blk_requeue_request(struct request_queue *q, struct request *rq) { blk_delete_timer(rq); blk_clear_rq_complete(rq); - blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); + trace_block_rq_requeue(q, rq); if (blk_rq_tagged(rq)) blk_queue_end_tag(q, rq); @@ -1167,7 +1175,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) if (!ll_back_merge_fn(q, req, bio)) break; - blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); + trace_block_bio_backmerge(q, bio); req->biotail->bi_next = bio; req->biotail = bio; @@ -1186,7 +1194,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) if (!ll_front_merge_fn(q, req, bio)) break; - blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); + trace_block_bio_frontmerge(q, bio); bio->bi_next = req->bio; req->bio = bio; @@ -1269,7 +1277,7 @@ static inline void blk_partition_remap(struct bio *bio) bio->bi_sector += p->start_sect; bio->bi_bdev = bdev->bd_contains; - blk_add_trace_remap(bdev_get_queue(bio->bi_bdev), bio, + trace_block_remap(bdev_get_queue(bio->bi_bdev), bio, bdev->bd_dev, bio->bi_sector, bio->bi_sector - p->start_sect); } @@ -1441,10 +1449,10 @@ end_io: goto end_io; if (old_sector != -1) - blk_add_trace_remap(q, bio, old_dev, bio->bi_sector, + trace_block_remap(q, bio, old_dev, bio->bi_sector, old_sector); - blk_add_trace_bio(q, bio, BLK_TA_QUEUE); + trace_block_bio_queue(q, bio); old_sector = bio->bi_sector; old_dev = bio->bi_bdev->bd_dev; @@ -1678,7 +1686,7 @@ static int __end_that_request_first(struct request *req, int error, int total_bytes, bio_nbytes, next_idx = 0; struct bio *bio; - blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE); + trace_block_rq_complete(req->q, req); /* * for a REQ_TYPE_BLOCK_PC request, we want to carry any eventual diff --git a/block/blktrace.c b/block/blktrace.c index 85049a7..b0a2cae 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -23,10 +23,18 @@ #include <linux/mutex.h> #include <linux/debugfs.h> #include <linux/time.h> +#include <trace/block.h> #include <asm/uaccess.h> static unsigned int blktrace_seq __read_mostly = 1; +/* Global reference count of probes */ +static DEFINE_MUTEX(blk_probe_mutex); +static atomic_t blk_probes_ref = ATOMIC_INIT(0); + +static int blk_register_tracepoints(void); +static void blk_unregister_tracepoints(void); + /* * Send out a notify message. */ @@ -119,7 +127,7 @@ static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK * The worker for the various blk_add_trace*() types. Fills out a * blk_io_trace structure and places it in a per-cpu subbuffer. */ -void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, +static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, int rw, u32 what, int error, int pdu_len, void *pdu_data) { struct task_struct *tsk = current; @@ -177,8 +185,6 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, local_irq_restore(flags); } -EXPORT_SYMBOL_GPL(__blk_add_trace); - static struct dentry *blk_tree_root; static DEFINE_MUTEX(blk_tree_mutex); static unsigned int root_users; @@ -237,6 +243,10 @@ static void blk_trace_cleanup(struct blk_trace *bt) free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt); + mutex_lock(&blk_probe_mutex); + if (atomic_dec_and_test(&blk_probes_ref)) + blk_unregister_tracepoints(); + mutex_unlock(&blk_probe_mutex); } int blk_trace_remove(struct request_queue *q) @@ -428,6 +438,14 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, bt->pid = buts->pid; bt->trace_state = Blktrace_setup; + mutex_lock(&blk_probe_mutex); + if (atomic_add_return(1, &blk_probes_ref) == 1) { + ret = blk_register_tracepoints(); + if (ret) + goto probe_err; + } + mutex_unlock(&blk_probe_mutex); + ret = -EBUSY; old_bt = xchg(&q->blk_trace, bt); if (old_bt) { @@ -436,6 +454,9 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, } return 0; +probe_err: + atomic_dec(&blk_probes_ref); + mutex_unlock(&blk_probe_mutex); err: if (dir) blk_remove_tree(dir); @@ -562,3 +583,308 @@ void blk_trace_shutdown(struct request_queue *q) blk_trace_remove(q); } } + +/* + * blktrace probes + */ + +/** + * blk_add_trace_rq - Add a trace for a request oriented action + * @q: queue the io is for + * @rq: the source request + * @what: the action + * + * Description: + * Records an action against a request. Will log the bio offset + size. + * + **/ +static void blk_add_trace_rq(struct request_queue *q, struct request *rq, + u32 what) +{ + struct blk_trace *bt = q->blk_trace; + int rw = rq->cmd_flags & 0x03; + + if (likely(!bt)) + return; + + if (blk_discard_rq(rq)) + rw |= (1 << BIO_RW_DISCARD); + + if (blk_pc_request(rq)) { + what |= BLK_TC_ACT(BLK_TC_PC); + __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, + sizeof(rq->cmd), rq->cmd); + } else { + what |= BLK_TC_ACT(BLK_TC_FS); + __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, + rw, what, rq->errors, 0, NULL); + } +} + +static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) +{ + blk_add_trace_rq(q, rq, BLK_TA_ABORT); +} + +static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) +{ + blk_add_trace_rq(q, rq, BLK_TA_INSERT); +} + +static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) +{ + blk_add_trace_rq(q, rq, BLK_TA_ISSUE); +} + +static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq) +{ + blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); +} + +static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq) +{ + blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); +} + +/** + * blk_add_trace_bio - Add a trace for a bio oriented action + * @q: queue the io is for + * @bio: the source bio + * @what: the action + * + * Description: + * Records an action against a bio. Will log the bio offset + size. + * + **/ +static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, + u32 what) +{ + struct blk_trace *bt = q->blk_trace; + + if (likely(!bt)) + return; + + __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, + !bio_flagged(bio, BIO_UPTODATE), 0, NULL); +} + +static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) +{ + blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); +} + +static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) +{ + blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); +} + +static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio) +{ + blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); +} + +static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio) +{ + blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); +} + +static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) +{ + blk_add_trace_bio(q, bio, BLK_TA_QUEUE); +} + +static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw) +{ + if (bio) + blk_add_trace_bio(q, bio, BLK_TA_GETRQ); + else { + struct blk_trace *bt = q->blk_trace; + + if (bt) + __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); + } +} + + +static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw) +{ + if (bio) + blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); + else { + struct blk_trace *bt = q->blk_trace; + + if (bt) + __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL); + } +} + +static void blk_add_trace_plug(struct request_queue *q) +{ + struct blk_trace *bt = q->blk_trace; + + if (bt) + __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); +} + +static void blk_add_trace_unplug_io(struct request_queue *q) +{ + struct blk_trace *bt = q->blk_trace; + + if (bt) { + unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; + __be64 rpdu = cpu_to_be64(pdu); + + __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, + sizeof(rpdu), &rpdu); + } +} + +static void blk_add_trace_unplug_timer(struct request_queue *q) +{ + struct blk_trace *bt = q->blk_trace; + + if (bt) { + unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; + __be64 rpdu = cpu_to_be64(pdu); + + __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, + sizeof(rpdu), &rpdu); + } +} + +static void blk_add_trace_split(struct request_queue *q, struct bio *bio, + unsigned int pdu) +{ + struct blk_trace *bt = q->blk_trace; + + if (bt) { + __be64 rpdu = cpu_to_be64(pdu); + + __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, + BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), + sizeof(rpdu), &rpdu); + } +} + +/** + * blk_add_trace_remap - Add a trace for a remap operation + * @q: queue the io is for + * @bio: the source bio + * @dev: target device + * @from: source sector + * @to: target sector + * + * Description: + * Device mapper or raid target sometimes need to split a bio because + * it spans a stripe (or similar). Add a trace for that action. + * + **/ +static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, + dev_t dev, sector_t from, sector_t to) +{ + struct blk_trace *bt = q->blk_trace; + struct blk_io_trace_remap r; + + if (likely(!bt)) + return; + + r.device = cpu_to_be32(dev); + r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); + r.sector = cpu_to_be64(to); + + __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, + !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); +} + +/** + * blk_add_driver_data - Add binary message with driver-specific data + * @q: queue the io is for + * @rq: io request + * @data: driver-specific data + * @len: length of driver-specific data + * + * Description: + * Some drivers might want to write driver-specific data per request. + * + **/ +void blk_add_driver_data(struct request_queue *q, + struct request *rq, + void *data, size_t len) +{ + struct blk_trace *bt = q->blk_trace; + + if (likely(!bt)) + return; + + if (blk_pc_request(rq)) + __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, + rq->errors, len, data); + else + __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, + 0, BLK_TA_DRV_DATA, rq->errors, len, data); +} +EXPORT_SYMBOL_GPL(blk_add_driver_data); + +static int blk_register_tracepoints(void) +{ + int ret; + + ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); + WARN_ON(ret); + ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); + WARN_ON(ret); + ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); + WARN_ON(ret); + ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); + WARN_ON(ret); + ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); + WARN_ON(ret); + ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); + WARN_ON(ret); + ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); + WARN_ON(ret); + ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); + WARN_ON(ret); + ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); + WARN_ON(ret); + ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); + WARN_ON(ret); + ret = register_trace_block_getrq(blk_add_trace_getrq); + WARN_ON(ret); + ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); + WARN_ON(ret); + ret = register_trace_block_plug(blk_add_trace_plug); + WARN_ON(ret); + ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); + WARN_ON(ret); + ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); + WARN_ON(ret); + ret = register_trace_block_split(blk_add_trace_split); + WARN_ON(ret); + ret = register_trace_block_remap(blk_add_trace_remap); + WARN_ON(ret); + return 0; +} + +static void blk_unregister_tracepoints(void) +{ + unregister_trace_block_remap(blk_add_trace_remap); + unregister_trace_block_split(blk_add_trace_split); + unregister_trace_block_unplug_io(blk_add_trace_unplug_io); + unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); + unregister_trace_block_plug(blk_add_trace_plug); + unregister_trace_block_sleeprq(blk_add_trace_sleeprq); + unregister_trace_block_getrq(blk_add_trace_getrq); + unregister_trace_block_bio_queue(blk_add_trace_bio_queue); + unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); + unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); + unregister_trace_block_bio_complete(blk_add_trace_bio_complete); + unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); + unregister_trace_block_rq_complete(blk_add_trace_rq_complete); + unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); + unregister_trace_block_rq_issue(blk_add_trace_rq_issue); + unregister_trace_block_rq_insert(blk_add_trace_rq_insert); + unregister_trace_block_rq_abort(blk_add_trace_rq_abort); + + tracepoint_synchronize_unregister(); +} diff --git a/block/elevator.c b/block/elevator.c index a6951f7..86836dd 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -33,6 +33,7 @@ #include <linux/compiler.h> #include <linux/delay.h> #include <linux/blktrace_api.h> +#include <trace/block.h> #include <linux/hash.h> #include <linux/uaccess.h> @@ -41,6 +42,8 @@ static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); +DEFINE_TRACE(block_rq_abort); + /* * Merge hash stuff. */ @@ -52,6 +55,9 @@ static const int elv_hash_shift = 6; #define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) +DEFINE_TRACE(block_rq_insert); +DEFINE_TRACE(block_rq_issue); + /* * Query io scheduler to see if the current process issuing bio may be * merged with rq. @@ -586,7 +592,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where) unsigned ordseq; int unplug_it = 1; - blk_add_trace_rq(q, rq, BLK_TA_INSERT); + trace_block_rq_insert(q, rq); rq->q = q; @@ -772,7 +778,7 @@ struct request *elv_next_request(struct request_queue *q) * not be passed by new incoming requests */ rq->cmd_flags |= REQ_STARTED; - blk_add_trace_rq(q, rq, BLK_TA_ISSUE); + trace_block_rq_issue(q, rq); } if (!q->boundary_rq || q->boundary_rq == rq) { @@ -914,7 +920,7 @@ void elv_abort_queue(struct request_queue *q) while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); rq->cmd_flags |= REQ_QUIET; - blk_add_trace_rq(q, rq, BLK_TA_ABORT); + trace_block_rq_abort(q, rq); __blk_end_request(rq, -EIO, blk_rq_bytes(rq)); } } |