From: Jens Axboe Date: Wed, 15 Feb 2006 09:37:41 +0000 (+0100) Subject: [PATCH] kernel: update to -rc3 (has little fixes/optimizations, too) X-Git-Tag: blktrace-0.99.1~34 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=c207e39393ddb803fa6e495daf6460c1bc49aa57;p=blktrace.git [PATCH] kernel: update to -rc3 (has little fixes/optimizations, too) --- diff --git a/kernel/blk-trace-2.6.16-rc2-git-B2 b/kernel/blk-trace-2.6.16-rc2-git-B2 deleted file mode 100644 index 0f493f0..0000000 --- a/kernel/blk-trace-2.6.16-rc2-git-B2 +++ /dev/null @@ -1,1223 +0,0 @@ -diff --git a/block/Kconfig b/block/Kconfig -index 377f6dd..27eaed9 100644 ---- a/block/Kconfig -+++ b/block/Kconfig -@@ -11,4 +11,15 @@ config LBD - your machine, or if you want to have a raid or loopback device - bigger than 2TB. Otherwise say N. - -+config BLK_DEV_IO_TRACE -+ bool "Support for tracing block io actions" -+ select RELAYFS_FS -+ 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 -+ on a block device queue. For more information (and the user space -+ support tools needed), fetch the blktrace app from: -+ -+ git://brick.kernel.dk/data/git/blktrace.git -+ - source block/Kconfig.iosched -diff --git a/block/Makefile b/block/Makefile -index 7e4f93e..c05de0e 100644 ---- a/block/Makefile -+++ b/block/Makefile -@@ -8,3 +8,5 @@ obj-$(CONFIG_IOSCHED_NOOP) += noop-iosch - obj-$(CONFIG_IOSCHED_AS) += as-iosched.o - obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o - obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o -+ -+obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o -diff --git a/block/blktrace.c b/block/blktrace.c -new file mode 100644 -index 0000000..3b03587 ---- /dev/null -+++ b/block/blktrace.c -@@ -0,0 +1,499 @@ -+#include -+#include -+#include -+#include -+#include -+#include -+#include -+#include -+ -+static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, }; -+static unsigned int blktrace_seq = 1; -+ -+static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) -+{ -+ struct blk_io_trace *t; -+ -+ t = relay_reserve(bt->rchan, sizeof(*t) + sizeof(tsk->comm)); -+ if (t) { -+ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; -+ t->device = bt->dev; -+ t->action = BLK_TC_ACT(BLK_TC_NOTIFY); -+ t->pid = tsk->pid; -+ t->cpu = smp_processor_id(); -+ t->pdu_len = sizeof(tsk->comm); -+ memcpy((void *) t + sizeof(*t), tsk->comm, t->pdu_len); -+ tsk->btrace_seq = blktrace_seq; -+ } -+} -+ -+static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, -+ pid_t pid) -+{ -+ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) -+ return 1; -+ if (sector < bt->start_lba || sector > bt->end_lba) -+ return 1; -+ if (bt->pid && pid != bt->pid) -+ return 1; -+ -+ return 0; -+} -+ -+/* -+ * Data direction bit lookup -+ */ -+static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) }; -+ -+/* -+ * Bio action bits of interest -+ */ -+static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC) }; -+ -+/* -+ * More could be added as needed, taking care to increment the decrementer -+ * to get correct indexing -+ */ -+#define trace_barrier_bit(rw) \ -+ (((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0)) -+#define trace_sync_bit(rw) \ -+ (((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1)) -+ -+/* -+ * 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, -+ int rw, u32 what, int error, int pdu_len, void *pdu_data) -+{ -+ struct task_struct *tsk = current; -+ struct blk_io_trace *t; -+ unsigned long flags; -+ unsigned long *sequence; -+ unsigned long seq; -+ u64 cpu_time; -+ pid_t pid; -+ int cpu; -+ -+ if (unlikely(bt->trace_state != Blktrace_running)) -+ return; -+ -+ what |= ddir_act[rw & WRITE]; -+ what |= bio_act[trace_barrier_bit(rw)]; -+ what |= bio_act[trace_sync_bit(rw)]; -+ -+ pid = tsk->pid; -+ if (unlikely(act_log_check(bt, what, sector, pid))) -+ return; -+ -+ /* -+ * A word about the locking here - we disable interrupts to reserve -+ * some space in the relayfs per-cpu buffer, to prevent an irq -+ * from coming in and stepping on our toes. Once reserved, it's -+ * enough to get preemption disabled to prevent read of this data -+ * before we are through filling it. get_cpu()/put_cpu() does this -+ * for us -+ */ -+ local_irq_save(flags); -+ -+ if (unlikely(tsk->btrace_seq != blktrace_seq)) -+ trace_note_tsk(bt, tsk); -+ -+ t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); -+ if (unlikely(!t)) { -+ local_irq_restore(flags); -+ return; -+ } -+ -+ cpu = get_cpu(); -+ -+ sequence = per_cpu_ptr(bt->sequence, cpu); -+ seq = ++(*sequence); -+ cpu_time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu); -+ -+ local_irq_restore(flags); -+ -+ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; -+ t->sequence = seq; -+ t->time = cpu_time; -+ t->sector = sector; -+ t->bytes = bytes; -+ t->action = what; -+ t->pid = pid; -+ t->device = bt->dev; -+ t->cpu = cpu; -+ t->error = error; -+ t->pdu_len = pdu_len; -+ -+ if (pdu_len) -+ memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); -+ -+ put_cpu(); -+} -+ -+EXPORT_SYMBOL_GPL(__blk_add_trace); -+ -+static struct dentry *blk_tree_root; -+static struct mutex blk_tree_mutex; -+ -+static inline void blk_remove_root(void) -+{ -+ if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY) -+ blk_tree_root = NULL; -+} -+ -+static void blk_remove_tree(struct dentry *dir) -+{ -+ mutex_lock(&blk_tree_mutex); -+ relayfs_remove_dir(dir); -+ blk_remove_root(); -+ mutex_unlock(&blk_tree_mutex); -+} -+ -+static struct dentry *blk_create_tree(const char *blk_name) -+{ -+ struct dentry *dir = NULL; -+ -+ mutex_lock(&blk_tree_mutex); -+ -+ if (!blk_tree_root) { -+ blk_tree_root = relayfs_create_dir("block", NULL); -+ if (!blk_tree_root) -+ goto err; -+ } -+ -+ dir = relayfs_create_dir(blk_name, blk_tree_root); -+ if (!dir) -+ blk_remove_root(); -+ -+err: -+ mutex_unlock(&blk_tree_mutex); -+ return dir; -+} -+ -+void blk_trace_cleanup(struct blk_trace *bt) -+{ -+ relay_close(bt->rchan); -+ relayfs_remove_file(bt->dropped_file); -+ blk_remove_tree(bt->dir); -+ free_percpu(bt->sequence); -+ kfree(bt); -+} -+ -+static int blk_trace_remove(request_queue_t *q) -+{ -+ struct blk_trace *bt; -+ -+ bt = xchg(&q->blk_trace, NULL); -+ if (!bt) -+ return -EINVAL; -+ -+ if (bt->trace_state == Blktrace_setup || -+ bt->trace_state == Blktrace_stopped) -+ blk_trace_cleanup(bt); -+ -+ return 0; -+} -+ -+static int blk_dropped_open(struct inode *inode, struct file *filp) -+{ -+ filp->private_data = inode->u.generic_ip; -+ -+ return 0; -+} -+ -+static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, -+ size_t count, loff_t *ppos) -+{ -+ struct blk_trace *bt = filp->private_data; -+ char buf[16]; -+ -+ snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); -+ -+ return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); -+} -+ -+static struct file_operations blk_dropped_fops = { -+ .owner = THIS_MODULE, -+ .open = blk_dropped_open, -+ .read = blk_dropped_read, -+}; -+ -+/* -+ * Keep track of how many times we encountered a full subbuffer, to aid -+ * the user space app in telling how many lost events there were. -+ */ -+static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, -+ void *prev_subbuf, size_t prev_padding) -+{ -+ struct blk_trace *bt; -+ -+ if (!relay_buf_full(buf)) -+ return 1; -+ -+ bt = buf->chan->private_data; -+ atomic_inc(&bt->dropped); -+ return 0; -+} -+ -+static struct rchan_callbacks blk_relay_callbacks = { -+ .subbuf_start = blk_subbuf_start_callback, -+}; -+ -+/* -+ * Setup everything required to start tracing -+ */ -+static int blk_trace_setup(request_queue_t *q, struct block_device *bdev, -+ char __user *arg) -+{ -+ struct blk_user_trace_setup buts; -+ struct blk_trace *old_bt, *bt = NULL; -+ struct dentry *dir = NULL; -+ char b[BDEVNAME_SIZE]; -+ int ret, i; -+ -+ if (copy_from_user(&buts, arg, sizeof(buts))) -+ return -EFAULT; -+ -+ if (!buts.buf_size || !buts.buf_nr) -+ return -EINVAL; -+ -+ strcpy(buts.name, bdevname(bdev, b)); -+ -+ /* -+ * some device names have larger paths - convert the slashes -+ * to underscores for this to work as expected -+ */ -+ for (i = 0; i < strlen(buts.name); i++) -+ if (buts.name[i] == '/') -+ buts.name[i] = '_'; -+ -+ if (copy_to_user(arg, &buts, sizeof(buts))) -+ return -EFAULT; -+ -+ ret = -ENOMEM; -+ bt = kzalloc(sizeof(*bt), GFP_KERNEL); -+ if (!bt) -+ goto err; -+ -+ bt->sequence = alloc_percpu(unsigned long); -+ if (!bt->sequence) -+ goto err; -+ -+ ret = -ENOENT; -+ dir = blk_create_tree(buts.name); -+ if (!dir) -+ goto err; -+ -+ bt->dir = dir; -+ bt->dev = bdev->bd_dev; -+ atomic_set(&bt->dropped, 0); -+ -+ ret = -EIO; -+ bt->dropped_file = relayfs_create_file("dropped", dir, 0, &blk_dropped_fops, bt); -+ if (!bt->dropped_file) -+ goto err; -+ -+ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks); -+ if (!bt->rchan) -+ goto err; -+ bt->rchan->private_data = bt; -+ -+ bt->act_mask = buts.act_mask; -+ if (!bt->act_mask) -+ bt->act_mask = (u16) -1; -+ -+ bt->start_lba = buts.start_lba; -+ bt->end_lba = buts.end_lba; -+ if (!bt->end_lba) -+ bt->end_lba = -1ULL; -+ -+ bt->pid = buts.pid; -+ bt->trace_state = Blktrace_setup; -+ -+ ret = -EBUSY; -+ old_bt = xchg(&q->blk_trace, bt); -+ if (old_bt) { -+ xchg(&q->blk_trace, old_bt); -+ goto err; -+ } -+ -+ return 0; -+err: -+ if (bt && bt->dropped_file) -+ relayfs_remove_file(bt->dropped_file); -+ if (dir) -+ blk_remove_tree(dir); -+ if (bt) { -+ if (bt->sequence) -+ free_percpu(bt->sequence); -+ kfree(bt); -+ } -+ return ret; -+} -+ -+static int blk_trace_startstop(request_queue_t *q, int start) -+{ -+ struct blk_trace *bt; -+ int ret; -+ -+ if ((bt = q->blk_trace) == NULL) -+ return -EINVAL; -+ -+ /* -+ * For starting a trace, we can transition from a setup or stopped -+ * trace. For stopping a trace, the state must be running -+ */ -+ ret = -EINVAL; -+ if (start) { -+ if (bt->trace_state == Blktrace_setup || -+ bt->trace_state == Blktrace_stopped) { -+ blktrace_seq++; -+ smp_mb(); -+ bt->trace_state = Blktrace_running; -+ ret = 0; -+ } -+ } else { -+ if (bt->trace_state == Blktrace_running) { -+ bt->trace_state = Blktrace_stopped; -+ ret = 0; -+ } -+ } -+ -+ return ret; -+} -+ -+/** -+ * blk_trace_ioctl: - handle the ioctls associated with tracing -+ * @bdev: the block device -+ * @cmd: the ioctl cmd -+ * @arg: the argument data, if any -+ * -+ **/ -+int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) -+{ -+ request_queue_t *q; -+ int ret, start = 0; -+ -+ q = bdev_get_queue(bdev); -+ if (!q) -+ return -ENXIO; -+ -+ down(&bdev->bd_sem); -+ -+ switch (cmd) { -+ case BLKTRACESETUP: -+ ret = blk_trace_setup(q, bdev, arg); -+ break; -+ case BLKTRACESTART: -+ start = 1; -+ case BLKTRACESTOP: -+ ret = blk_trace_startstop(q, start); -+ break; -+ case BLKTRACETEARDOWN: -+ ret = blk_trace_remove(q); -+ break; -+ default: -+ ret = -ENOTTY; -+ break; -+ } -+ -+ up(&bdev->bd_sem); -+ return ret; -+} -+ -+/** -+ * blk_trace_shutdown: - stop and cleanup trace structures -+ * @q: the request queue associated with the device -+ * -+ **/ -+void blk_trace_shutdown(request_queue_t *q) -+{ -+ blk_trace_startstop(q, 0); -+ blk_trace_remove(q); -+} -+ -+/* -+ * Average offset over two calls to sched_clock() with a gettimeofday() -+ * in the middle -+ */ -+static void blk_check_time(unsigned long long *t) -+{ -+ unsigned long long a, b; -+ struct timeval tv; -+ -+ a = sched_clock(); -+ do_gettimeofday(&tv); -+ b = sched_clock(); -+ -+ *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000; -+ *t -= (a + b) / 2; -+} -+ -+static void blk_trace_check_cpu_time(void *data) -+{ -+ unsigned long long *t; -+ int cpu = get_cpu(); -+ -+ t = &per_cpu(blk_trace_cpu_offset, cpu); -+ -+ /* -+ * Just call it twice, hopefully the second call will be cache hot -+ * and a little more precise -+ */ -+ blk_check_time(t); -+ blk_check_time(t); -+ -+ put_cpu(); -+} -+ -+/* -+ * Call blk_trace_check_cpu_time() on each CPU to calibrate our inter-CPU -+ * timings -+ */ -+static void blk_trace_calibrate_offsets(void) -+{ -+ unsigned long flags; -+ -+ smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1); -+ local_irq_save(flags); -+ blk_trace_check_cpu_time(NULL); -+ local_irq_restore(flags); -+} -+ -+static void blk_trace_set_ht_offsets(void) -+{ -+#if defined(CONFIG_SCHED_SMT) -+ int cpu, i; -+ -+ /* -+ * now make sure HT siblings have the same time offset -+ */ -+ preempt_disable(); -+ for_each_online_cpu(cpu) { -+ unsigned long long *cpu_off, *sibling_off; -+ -+ for_each_cpu_mask(i, cpu_sibling_map[cpu]) { -+ if (i == cpu) -+ continue; -+ -+ cpu_off = &per_cpu(blk_trace_cpu_offset, cpu); -+ sibling_off = &per_cpu(blk_trace_cpu_offset, i); -+ *sibling_off = *cpu_off; -+ } -+ } -+ preempt_enable(); -+#endif -+} -+ -+static __init int blk_trace_init(void) -+{ -+ mutex_init(&blk_tree_mutex); -+ blk_trace_calibrate_offsets(); -+ blk_trace_set_ht_offsets(); -+ -+ return 0; -+} -+ -+module_init(blk_trace_init); -+ -diff --git a/block/elevator.c b/block/elevator.c -index 24b702d..0c9fafe 100644 ---- a/block/elevator.c -+++ b/block/elevator.c -@@ -33,6 +33,7 @@ - #include - #include - #include -+#include - - #include - -@@ -315,6 +316,8 @@ void elv_insert(request_queue_t *q, stru - struct list_head *pos; - unsigned ordseq; - -+ blk_add_trace_rq(q, rq, BLK_TA_INSERT); -+ - rq->q = q; - - switch (where) { -@@ -481,6 +484,7 @@ struct request *elv_next_request(request - * not be passed by new incoming requests - */ - rq->flags |= REQ_STARTED; -+ blk_add_trace_rq(q, rq, BLK_TA_ISSUE); - } - - if (!q->boundary_rq || q->boundary_rq == rq) { -diff --git a/block/ioctl.c b/block/ioctl.c -index e110949..7acb56c 100644 ---- a/block/ioctl.c -+++ b/block/ioctl.c -@@ -5,6 +5,7 @@ - #include - #include - #include -+#include - #include - - static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg) -@@ -189,6 +190,11 @@ static int blkdev_locked_ioctl(struct fi - return put_ulong(arg, bdev->bd_inode->i_size >> 9); - case BLKGETSIZE64: - return put_u64(arg, bdev->bd_inode->i_size); -+ case BLKTRACESTART: -+ case BLKTRACESTOP: -+ case BLKTRACESETUP: -+ case BLKTRACETEARDOWN: -+ return blk_trace_ioctl(bdev, cmd, (char __user *) arg); - } - return -ENOIOCTLCMD; - } -diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c -index 03d9c82..41387f5 100644 ---- a/block/ll_rw_blk.c -+++ b/block/ll_rw_blk.c -@@ -28,6 +28,7 @@ - #include - #include - #include -+#include - - /* - * for max sense size -@@ -1551,8 +1552,10 @@ void blk_plug_device(request_queue_t *q) - if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)) - return; - -- if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) -+ if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) { - mod_timer(&q->unplug_timer, jiffies + q->unplug_delay); -+ blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG); -+ } - } - - EXPORT_SYMBOL(blk_plug_device); -@@ -1616,14 +1619,21 @@ static void blk_backing_dev_unplug(struc - /* - * devices don't necessarily have an ->unplug_fn defined - */ -- if (q->unplug_fn) -+ if (q->unplug_fn) { -+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, -+ q->rq.count[READ] + q->rq.count[WRITE]); -+ - q->unplug_fn(q); -+ } - } - - static void blk_unplug_work(void *data) - { - request_queue_t *q = data; - -+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, -+ q->rq.count[READ] + q->rq.count[WRITE]); -+ - q->unplug_fn(q); - } - -@@ -1631,6 +1641,9 @@ static void blk_unplug_timeout(unsigned - { - request_queue_t *q = (request_queue_t *)data; - -+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL, -+ q->rq.count[READ] + q->rq.count[WRITE]); -+ - kblockd_schedule_work(&q->unplug_work); - } - -@@ -1753,6 +1766,9 @@ void blk_cleanup_queue(request_queue_t * - if (q->queue_tags) - __blk_queue_free_tags(q); - -+ if (q->blk_trace) -+ blk_trace_shutdown(q); -+ - kmem_cache_free(requestq_cachep, q); - } - -@@ -2104,6 +2120,8 @@ rq_starved: - - rq_init(q, rq); - rq->rl = rl; -+ -+ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ); - out: - return rq; - } -@@ -2132,6 +2150,8 @@ static struct request *get_request_wait( - if (!rq) { - struct io_context *ioc; - -+ blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); -+ - __generic_unplug_device(q); - spin_unlock_irq(q->queue_lock); - io_schedule(); -@@ -2185,6 +2205,8 @@ EXPORT_SYMBOL(blk_get_request); - */ - void blk_requeue_request(request_queue_t *q, struct request *rq) - { -+ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); -+ - if (blk_rq_tagged(rq)) - blk_queue_end_tag(q, rq); - -@@ -2819,6 +2841,8 @@ static int __make_request(request_queue_ - if (!q->back_merge_fn(q, req, bio)) - break; - -+ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); -+ - req->biotail->bi_next = bio; - req->biotail = bio; - req->nr_sectors = req->hard_nr_sectors += nr_sectors; -@@ -2834,6 +2858,8 @@ static int __make_request(request_queue_ - if (!q->front_merge_fn(q, req, bio)) - break; - -+ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); -+ - bio->bi_next = req->bio; - req->bio = bio; - -@@ -2951,6 +2977,7 @@ void generic_make_request(struct bio *bi - request_queue_t *q; - sector_t maxsector; - int ret, nr_sectors = bio_sectors(bio); -+ dev_t old_dev; - - might_sleep(); - /* Test device or partition size, when known. */ -@@ -2977,6 +3004,8 @@ void generic_make_request(struct bio *bi - * NOTE: we don't repeat the blk_size check for each new device. - * Stacking drivers are expected to know what they are doing. - */ -+ maxsector = -1; -+ old_dev = 0; - do { - char b[BDEVNAME_SIZE]; - -@@ -3009,6 +3038,15 @@ end_io: - */ - blk_partition_remap(bio); - -+ if (maxsector != -1) -+ blk_add_trace_remap(q, bio, old_dev, bio->bi_sector, -+ maxsector); -+ -+ blk_add_trace_bio(q, bio, BLK_TA_QUEUE); -+ -+ maxsector = bio->bi_sector; -+ old_dev = bio->bi_bdev->bd_dev; -+ - ret = q->make_request_fn(q, bio); - } while (ret); - } -@@ -3128,6 +3166,8 @@ static int __end_that_request_first(stru - int total_bytes, bio_nbytes, error, next_idx = 0; - struct bio *bio; - -+ blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE); -+ - /* - * extend uptodate bool to allow < 0 value to be direct io error - */ -diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c -index 0d65394..234048e 100644 ---- a/drivers/block/cciss.c -+++ b/drivers/block/cciss.c -@@ -38,6 +38,7 @@ - #include - #include - #include -+#include - #include - #include - -@@ -2331,6 +2332,7 @@ static inline void complete_command( ctl - - cmd->rq->completion_data = cmd; - cmd->rq->errors = status; -+ blk_add_trace_rq(cmd->rq->q, cmd->rq, BLK_TA_COMPLETE); - blk_complete_request(cmd->rq); - } - -diff --git a/drivers/md/dm.c b/drivers/md/dm.c -index e9adeb9..c8f3aa2 100644 ---- a/drivers/md/dm.c -+++ b/drivers/md/dm.c -@@ -17,6 +17,7 @@ - #include - #include - #include -+#include - - static const char *_name = DM_NAME; - -@@ -334,6 +335,8 @@ static void dec_pending(struct dm_io *io - /* nudge anyone waiting on suspend queue */ - wake_up(&io->md->wait); - -+ blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); -+ - bio_endio(io->bio, io->bio->bi_size, io->error); - free_io(io->md, io); - } -@@ -392,6 +395,7 @@ static void __map_bio(struct dm_target * - struct target_io *tio) - { - int r; -+ sector_t sector; - - /* - * Sanity checks. -@@ -407,10 +411,17 @@ static void __map_bio(struct dm_target * - * this io. - */ - atomic_inc(&tio->io->io_count); -+ sector = clone->bi_sector; - r = ti->type->map(ti, clone, &tio->info); -- if (r > 0) -+ if (r > 0) { - /* the bio has been remapped so dispatch it */ -+ -+ blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, -+ tio->io->bio->bi_bdev->bd_dev, sector, -+ clone->bi_sector); -+ - generic_make_request(clone); -+ } - - else if (r < 0) { - /* error the io and bail out */ -diff --git a/fs/bio.c b/fs/bio.c -index 1f3bb50..0dd0d81 100644 ---- a/fs/bio.c -+++ b/fs/bio.c -@@ -25,6 +25,7 @@ - #include - #include - #include -+#include - #include /* for struct sg_iovec */ - - #define BIO_POOL_SIZE 256 -@@ -1095,6 +1096,9 @@ struct bio_pair *bio_split(struct bio *b - if (!bp) - return bp; - -+ blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi, -+ bi->bi_sector + first_sectors); -+ - BUG_ON(bi->bi_vcnt != 1); - BUG_ON(bi->bi_idx != 0); - atomic_set(&bp->cnt, 3); -diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c -index 057e602..893d600 100644 ---- a/fs/compat_ioctl.c -+++ b/fs/compat_ioctl.c -@@ -72,6 +72,7 @@ - #include - #include - #include -+#include - - #include /* siocdevprivate_ioctl */ - #include -diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h -index 860e7a4..266ce9d 100644 ---- a/include/linux/blkdev.h -+++ b/include/linux/blkdev.h -@@ -22,6 +22,7 @@ typedef struct request_queue request_que - struct elevator_queue; - typedef struct elevator_queue elevator_t; - struct request_pm_state; -+struct blk_trace; - - #define BLKDEV_MIN_RQ 4 - #define BLKDEV_MAX_RQ 128 /* Default maximum */ -@@ -416,6 +417,8 @@ struct request_queue - unsigned int sg_reserved_size; - int node; - -+ struct blk_trace *blk_trace; -+ - /* - * reserved for flush operations - */ -diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h -new file mode 100644 -index 0000000..fca40ef ---- /dev/null -+++ b/include/linux/blktrace_api.h -@@ -0,0 +1,277 @@ -+#ifndef BLKTRACE_H -+#define BLKTRACE_H -+ -+#include -+#include -+#include -+ -+/* -+ * Trace categories -+ */ -+enum blktrace_cat { -+ BLK_TC_READ = 1 << 0, /* reads */ -+ BLK_TC_WRITE = 1 << 1, /* writes */ -+ BLK_TC_BARRIER = 1 << 2, /* barrier */ -+ BLK_TC_SYNC = 1 << 3, /* barrier */ -+ BLK_TC_QUEUE = 1 << 4, /* queueing/merging */ -+ BLK_TC_REQUEUE = 1 << 5, /* requeueing */ -+ BLK_TC_ISSUE = 1 << 6, /* issue */ -+ BLK_TC_COMPLETE = 1 << 7, /* completions */ -+ BLK_TC_FS = 1 << 8, /* fs requests */ -+ BLK_TC_PC = 1 << 9, /* pc requests */ -+ BLK_TC_NOTIFY = 1 << 10, /* special message */ -+ -+ BLK_TC_END = 1 << 15, /* only 16-bits, reminder */ -+}; -+ -+#define BLK_TC_SHIFT (16) -+#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT) -+ -+/* -+ * Basic trace actions -+ */ -+enum blktrace_act { -+ __BLK_TA_QUEUE = 1, /* queued */ -+ __BLK_TA_BACKMERGE, /* back merged to existing rq */ -+ __BLK_TA_FRONTMERGE, /* front merge to existing rq */ -+ __BLK_TA_GETRQ, /* allocated new request */ -+ __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */ -+ __BLK_TA_REQUEUE, /* request requeued */ -+ __BLK_TA_ISSUE, /* sent to driver */ -+ __BLK_TA_COMPLETE, /* completed by driver */ -+ __BLK_TA_PLUG, /* queue was plugged */ -+ __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */ -+ __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */ -+ __BLK_TA_INSERT, /* insert request */ -+ __BLK_TA_SPLIT, /* bio was split */ -+ __BLK_TA_BOUNCE, /* bio was bounced */ -+ __BLK_TA_REMAP, /* bio was remapped */ -+}; -+ -+/* -+ * Trace actions in full. Additionally, read or write is masked -+ */ -+#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE)) -+#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE)) -+#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE)) -+#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE)) -+#define BLK_TA_SPLIT (__BLK_TA_SPLIT) -+#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE) -+#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE)) -+ -+#define BLK_IO_TRACE_MAGIC 0x65617400 -+#define BLK_IO_TRACE_VERSION 0x07 -+ -+/* -+ * The trace itself -+ */ -+struct blk_io_trace { -+ u32 magic; /* MAGIC << 8 | version */ -+ u32 sequence; /* event number */ -+ u64 time; /* in microseconds */ -+ u64 sector; /* disk offset */ -+ u32 bytes; /* transfer length */ -+ u32 action; /* what happened */ -+ u32 pid; /* who did it */ -+ u32 device; /* device number */ -+ u32 cpu; /* on what cpu did it happen */ -+ u16 error; /* completion error */ -+ u16 pdu_len; /* length of data after this trace */ -+}; -+ -+/* -+ * The remap event -+ */ -+struct blk_io_trace_remap { -+ u32 device; -+ u32 __pad; -+ u64 sector; -+}; -+ -+enum { -+ Blktrace_setup = 1, -+ Blktrace_running, -+ Blktrace_stopped, -+}; -+ -+struct blk_trace { -+ int trace_state; -+ struct dentry *dir; -+ struct rchan *rchan; -+ struct dentry *dropped_file; -+ atomic_t dropped; -+ unsigned long *sequence; -+ u32 dev; -+ u16 act_mask; -+ u64 start_lba; -+ u64 end_lba; -+ u32 pid; -+}; -+ -+/* -+ * User setup structure passed with BLKTRACESTART -+ */ -+struct blk_user_trace_setup { -+ char name[BDEVNAME_SIZE]; /* output */ -+ u16 act_mask; /* input */ -+ u32 buf_size; /* input */ -+ u32 buf_nr; /* input */ -+ u64 start_lba; -+ u64 end_lba; -+ u32 pid; -+}; -+ -+#if defined(CONFIG_BLK_DEV_IO_TRACE) -+extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *); -+extern void blk_trace_shutdown(request_queue_t *); -+extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *); -+ -+/** -+ * 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 inline void blk_add_trace_rq(struct request_queue *q, struct request *rq, -+ u32 what) -+{ -+ struct blk_trace *bt = q->blk_trace; -+ int rw = rq->flags & 0x07; -+ -+ if (likely(!bt)) -+ return; -+ -+ 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); -+ } -+} -+ -+/** -+ * 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 inline 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); -+} -+ -+/** -+ * blk_add_trace_generic - Add a trace for a generic action -+ * @q: queue the io is for -+ * @bio: the source bio -+ * @rw: the data direction -+ * @what: the action -+ * -+ * Description: -+ * Records a simple trace -+ * -+ **/ -+static inline void blk_add_trace_generic(struct request_queue *q, -+ struct bio *bio, int rw, u32 what) -+{ -+ struct blk_trace *bt = q->blk_trace; -+ -+ if (likely(!bt)) -+ return; -+ -+ if (bio) -+ blk_add_trace_bio(q, bio, what); -+ else -+ __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL); -+} -+ -+/** -+ * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload -+ * @q: queue the io is for -+ * @what: the action -+ * @bio: the source bio -+ * @pdu: the integer payload -+ * -+ * Description: -+ * Adds a trace with some integer payload. This might be an unplug -+ * option given as the action, with the depth at unplug time given -+ * as the payload -+ * -+ **/ -+static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what, -+ struct bio *bio, unsigned int pdu) -+{ -+ struct blk_trace *bt = q->blk_trace; -+ u64 rpdu = cpu_to_be64(pdu); -+ -+ if (likely(!bt)) -+ return; -+ -+ if (bio) -+ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu); -+ else -+ __blk_add_trace(bt, 0, 0, 0, what, 0, 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 inline 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.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); -+} -+ -+#else /* !CONFIG_BLK_DEV_IO_TRACE */ -+#define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY) -+#define blk_trace_shutdown(q) do { } while (0) -+#define blk_add_trace_rq(q, rq, what) do { } while (0) -+#define blk_add_trace_bio(q, rq, what) do { } while (0) -+#define blk_add_trace_generic(q, rq, rw, what) do { } while (0) -+#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0) -+#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0) -+#endif /* CONFIG_BLK_DEV_IO_TRACE */ -+ -+#endif -diff --git a/include/linux/compat_ioctl.h b/include/linux/compat_ioctl.h -index 8fad50f..a3ed64b 100644 ---- a/include/linux/compat_ioctl.h -+++ b/include/linux/compat_ioctl.h -@@ -97,6 +97,10 @@ COMPATIBLE_IOCTL(BLKRRPART) - COMPATIBLE_IOCTL(BLKFLSBUF) - COMPATIBLE_IOCTL(BLKSECTSET) - COMPATIBLE_IOCTL(BLKSSZGET) -+COMPATIBLE_IOCTL(BLKTRACESTART) -+COMPATIBLE_IOCTL(BLKTRACESTOP) -+COMPATIBLE_IOCTL(BLKTRACESETUP) -+COMPATIBLE_IOCTL(BLKTRACETEARDOWN) - ULONG_IOCTL(BLKRASET) - ULONG_IOCTL(BLKFRASET) - /* RAID */ -diff --git a/include/linux/fs.h b/include/linux/fs.h -index e059da9..c7a63cd 100644 ---- a/include/linux/fs.h -+++ b/include/linux/fs.h -@@ -196,6 +196,10 @@ extern int dir_notify_enable; - #define BLKBSZGET _IOR(0x12,112,size_t) - #define BLKBSZSET _IOW(0x12,113,size_t) - #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */ -+#define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup) -+#define BLKTRACESTART _IO(0x12,116) -+#define BLKTRACESTOP _IO(0x12,117) -+#define BLKTRACETEARDOWN _IO(0x12,118) - - #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ - #define FIBMAP _IO(0x00,1) /* bmap access */ -diff --git a/include/linux/sched.h b/include/linux/sched.h -index 0cfcd1c..69cd119 100644 ---- a/include/linux/sched.h -+++ b/include/linux/sched.h -@@ -708,6 +708,7 @@ struct task_struct { - prio_array_t *array; - - unsigned short ioprio; -+ unsigned int btrace_seq; - - unsigned long sleep_avg; - unsigned long long timestamp, last_ran; -diff --git a/kernel/fork.c b/kernel/fork.c -index 8e88b37..60f838f 100644 ---- a/kernel/fork.c -+++ b/kernel/fork.c -@@ -179,6 +179,7 @@ static struct task_struct *dup_task_stru - /* One for us, one for whoever does the "release_task()" (usually parent) */ - atomic_set(&tsk->usage,2); - atomic_set(&tsk->fs_excl, 0); -+ tsk->btrace_seq = 0; - return tsk; - } - -diff --git a/mm/highmem.c b/mm/highmem.c -index ce2e7e8..d0ea1ee 100644 ---- a/mm/highmem.c -+++ b/mm/highmem.c -@@ -26,6 +26,7 @@ - #include - #include - #include -+#include - #include - - static mempool_t *page_pool, *isa_page_pool; -@@ -483,6 +484,8 @@ void blk_queue_bounce(request_queue_t *q - pool = isa_page_pool; - } - -+ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE); -+ - /* - * slow path - */ diff --git a/kernel/blk-trace-2.6.16-rc3-git-A0 b/kernel/blk-trace-2.6.16-rc3-git-A0 new file mode 100644 index 0000000..1174258 --- /dev/null +++ b/kernel/blk-trace-2.6.16-rc3-git-A0 @@ -0,0 +1,1220 @@ +diff --git a/block/Kconfig b/block/Kconfig +index 377f6dd..27eaed9 100644 +--- a/block/Kconfig ++++ b/block/Kconfig +@@ -11,4 +11,15 @@ config LBD + your machine, or if you want to have a raid or loopback device + bigger than 2TB. Otherwise say N. + ++config BLK_DEV_IO_TRACE ++ bool "Support for tracing block io actions" ++ select RELAYFS_FS ++ 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 ++ on a block device queue. For more information (and the user space ++ support tools needed), fetch the blktrace app from: ++ ++ git://brick.kernel.dk/data/git/blktrace.git ++ + source block/Kconfig.iosched +diff --git a/block/Makefile b/block/Makefile +index 7e4f93e..c05de0e 100644 +--- a/block/Makefile ++++ b/block/Makefile +@@ -8,3 +8,5 @@ obj-$(CONFIG_IOSCHED_NOOP) += noop-iosch + obj-$(CONFIG_IOSCHED_AS) += as-iosched.o + obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o + obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o ++ ++obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o +diff --git a/block/blktrace.c b/block/blktrace.c +new file mode 100644 +index 0000000..e00458e +--- /dev/null ++++ b/block/blktrace.c +@@ -0,0 +1,496 @@ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, }; ++static unsigned int blktrace_seq __read_mostly = 1; ++ ++/* ++ * Send out a notify for this process, if we haven't done so since a trace ++ * started ++ */ ++static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) ++{ ++ struct blk_io_trace *t; ++ ++ t = relay_reserve(bt->rchan, sizeof(*t) + sizeof(tsk->comm)); ++ if (t) { ++ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; ++ t->device = bt->dev; ++ t->action = BLK_TC_ACT(BLK_TC_NOTIFY); ++ t->pid = tsk->pid; ++ t->cpu = smp_processor_id(); ++ t->pdu_len = sizeof(tsk->comm); ++ memcpy((void *) t + sizeof(*t), tsk->comm, t->pdu_len); ++ tsk->btrace_seq = blktrace_seq; ++ } ++} ++ ++static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, ++ pid_t pid) ++{ ++ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) ++ return 1; ++ if (sector < bt->start_lba || sector > bt->end_lba) ++ return 1; ++ if (bt->pid && pid != bt->pid) ++ return 1; ++ ++ return 0; ++} ++ ++/* ++ * Data direction bit lookup ++ */ ++static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) }; ++ ++/* ++ * Bio action bits of interest ++ */ ++static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC) }; ++ ++/* ++ * More could be added as needed, taking care to increment the decrementer ++ * to get correct indexing ++ */ ++#define trace_barrier_bit(rw) \ ++ (((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0)) ++#define trace_sync_bit(rw) \ ++ (((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1)) ++ ++/* ++ * 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, ++ int rw, u32 what, int error, int pdu_len, void *pdu_data) ++{ ++ struct task_struct *tsk = current; ++ struct blk_io_trace *t; ++ unsigned long flags; ++ unsigned long *sequence; ++ pid_t pid; ++ int cpu; ++ ++ if (unlikely(bt->trace_state != Blktrace_running)) ++ return; ++ ++ what |= ddir_act[rw & WRITE]; ++ what |= bio_act[trace_barrier_bit(rw)]; ++ what |= bio_act[trace_sync_bit(rw)]; ++ ++ pid = tsk->pid; ++ if (unlikely(act_log_check(bt, what, sector, pid))) ++ return; ++ ++ /* ++ * A word about the locking here - we disable interrupts to reserve ++ * some space in the relayfs per-cpu buffer, to prevent an irq ++ * from coming in and stepping on our toes. Once reserved, it's ++ * enough to get preemption disabled to prevent read of this data ++ * before we are through filling it. get_cpu()/put_cpu() does this ++ * for us ++ */ ++ local_irq_save(flags); ++ ++ if (unlikely(tsk->btrace_seq != blktrace_seq)) ++ trace_note_tsk(bt, tsk); ++ ++ t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); ++ if (t) { ++ cpu = smp_processor_id(); ++ sequence = per_cpu_ptr(bt->sequence, cpu); ++ ++ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; ++ t->sequence = ++(*sequence); ++ t->time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu); ++ t->sector = sector; ++ t->bytes = bytes; ++ t->action = what; ++ t->pid = pid; ++ t->device = bt->dev; ++ t->cpu = cpu; ++ t->error = error; ++ t->pdu_len = pdu_len; ++ ++ if (pdu_len) ++ memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); ++ } ++ ++ local_irq_restore(flags); ++} ++ ++EXPORT_SYMBOL_GPL(__blk_add_trace); ++ ++static struct dentry *blk_tree_root; ++static struct mutex blk_tree_mutex; ++ ++static inline void blk_remove_root(void) ++{ ++ if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY) ++ blk_tree_root = NULL; ++} ++ ++static void blk_remove_tree(struct dentry *dir) ++{ ++ mutex_lock(&blk_tree_mutex); ++ relayfs_remove_dir(dir); ++ blk_remove_root(); ++ mutex_unlock(&blk_tree_mutex); ++} ++ ++static struct dentry *blk_create_tree(const char *blk_name) ++{ ++ struct dentry *dir = NULL; ++ ++ mutex_lock(&blk_tree_mutex); ++ ++ if (!blk_tree_root) { ++ blk_tree_root = relayfs_create_dir("block", NULL); ++ if (!blk_tree_root) ++ goto err; ++ } ++ ++ dir = relayfs_create_dir(blk_name, blk_tree_root); ++ if (!dir) ++ blk_remove_root(); ++ ++err: ++ mutex_unlock(&blk_tree_mutex); ++ return dir; ++} ++ ++static void blk_trace_cleanup(struct blk_trace *bt) ++{ ++ relay_close(bt->rchan); ++ relayfs_remove_file(bt->dropped_file); ++ blk_remove_tree(bt->dir); ++ free_percpu(bt->sequence); ++ kfree(bt); ++} ++ ++static int blk_trace_remove(request_queue_t *q) ++{ ++ struct blk_trace *bt; ++ ++ bt = xchg(&q->blk_trace, NULL); ++ if (!bt) ++ return -EINVAL; ++ ++ if (bt->trace_state == Blktrace_setup || ++ bt->trace_state == Blktrace_stopped) ++ blk_trace_cleanup(bt); ++ ++ return 0; ++} ++ ++static int blk_dropped_open(struct inode *inode, struct file *filp) ++{ ++ filp->private_data = inode->u.generic_ip; ++ ++ return 0; ++} ++ ++static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, ++ size_t count, loff_t *ppos) ++{ ++ struct blk_trace *bt = filp->private_data; ++ char buf[16]; ++ ++ snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); ++ ++ return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); ++} ++ ++static struct file_operations blk_dropped_fops = { ++ .owner = THIS_MODULE, ++ .open = blk_dropped_open, ++ .read = blk_dropped_read, ++}; ++ ++/* ++ * Keep track of how many times we encountered a full subbuffer, to aid ++ * the user space app in telling how many lost events there were. ++ */ ++static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, ++ void *prev_subbuf, size_t prev_padding) ++{ ++ struct blk_trace *bt; ++ ++ if (!relay_buf_full(buf)) ++ return 1; ++ ++ bt = buf->chan->private_data; ++ atomic_inc(&bt->dropped); ++ return 0; ++} ++ ++static struct rchan_callbacks blk_relay_callbacks = { ++ .subbuf_start = blk_subbuf_start_callback, ++}; ++ ++/* ++ * Setup everything required to start tracing ++ */ ++static int blk_trace_setup(request_queue_t *q, struct block_device *bdev, ++ char __user *arg) ++{ ++ struct blk_user_trace_setup buts; ++ struct blk_trace *old_bt, *bt = NULL; ++ struct dentry *dir = NULL; ++ char b[BDEVNAME_SIZE]; ++ int ret, i; ++ ++ if (copy_from_user(&buts, arg, sizeof(buts))) ++ return -EFAULT; ++ ++ if (!buts.buf_size || !buts.buf_nr) ++ return -EINVAL; ++ ++ strcpy(buts.name, bdevname(bdev, b)); ++ ++ /* ++ * some device names have larger paths - convert the slashes ++ * to underscores for this to work as expected ++ */ ++ for (i = 0; i < strlen(buts.name); i++) ++ if (buts.name[i] == '/') ++ buts.name[i] = '_'; ++ ++ if (copy_to_user(arg, &buts, sizeof(buts))) ++ return -EFAULT; ++ ++ ret = -ENOMEM; ++ bt = kzalloc(sizeof(*bt), GFP_KERNEL); ++ if (!bt) ++ goto err; ++ ++ bt->sequence = alloc_percpu(unsigned long); ++ if (!bt->sequence) ++ goto err; ++ ++ ret = -ENOENT; ++ dir = blk_create_tree(buts.name); ++ if (!dir) ++ goto err; ++ ++ bt->dir = dir; ++ bt->dev = bdev->bd_dev; ++ atomic_set(&bt->dropped, 0); ++ ++ ret = -EIO; ++ bt->dropped_file = relayfs_create_file("dropped", dir, 0, &blk_dropped_fops, bt); ++ if (!bt->dropped_file) ++ goto err; ++ ++ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks); ++ if (!bt->rchan) ++ goto err; ++ bt->rchan->private_data = bt; ++ ++ bt->act_mask = buts.act_mask; ++ if (!bt->act_mask) ++ bt->act_mask = (u16) -1; ++ ++ bt->start_lba = buts.start_lba; ++ bt->end_lba = buts.end_lba; ++ if (!bt->end_lba) ++ bt->end_lba = -1ULL; ++ ++ bt->pid = buts.pid; ++ bt->trace_state = Blktrace_setup; ++ ++ ret = -EBUSY; ++ old_bt = xchg(&q->blk_trace, bt); ++ if (old_bt) { ++ xchg(&q->blk_trace, old_bt); ++ goto err; ++ } ++ ++ return 0; ++err: ++ if (bt && bt->dropped_file) ++ relayfs_remove_file(bt->dropped_file); ++ if (dir) ++ blk_remove_tree(dir); ++ if (bt) { ++ if (bt->sequence) ++ free_percpu(bt->sequence); ++ if (bt->rchan) ++ relay_close(bt->rchan); ++ kfree(bt); ++ } ++ return ret; ++} ++ ++static int blk_trace_startstop(request_queue_t *q, int start) ++{ ++ struct blk_trace *bt; ++ int ret; ++ ++ if ((bt = q->blk_trace) == NULL) ++ return -EINVAL; ++ ++ /* ++ * For starting a trace, we can transition from a setup or stopped ++ * trace. For stopping a trace, the state must be running ++ */ ++ ret = -EINVAL; ++ if (start) { ++ if (bt->trace_state == Blktrace_setup || ++ bt->trace_state == Blktrace_stopped) { ++ blktrace_seq++; ++ smp_mb(); ++ bt->trace_state = Blktrace_running; ++ ret = 0; ++ } ++ } else { ++ if (bt->trace_state == Blktrace_running) { ++ bt->trace_state = Blktrace_stopped; ++ relay_flush(bt->rchan); ++ ret = 0; ++ } ++ } ++ ++ return ret; ++} ++ ++/** ++ * blk_trace_ioctl: - handle the ioctls associated with tracing ++ * @bdev: the block device ++ * @cmd: the ioctl cmd ++ * @arg: the argument data, if any ++ * ++ **/ ++int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) ++{ ++ request_queue_t *q; ++ int ret, start = 0; ++ ++ q = bdev_get_queue(bdev); ++ if (!q) ++ return -ENXIO; ++ ++ down(&bdev->bd_sem); ++ ++ switch (cmd) { ++ case BLKTRACESETUP: ++ ret = blk_trace_setup(q, bdev, arg); ++ break; ++ case BLKTRACESTART: ++ start = 1; ++ case BLKTRACESTOP: ++ ret = blk_trace_startstop(q, start); ++ break; ++ case BLKTRACETEARDOWN: ++ ret = blk_trace_remove(q); ++ break; ++ default: ++ ret = -ENOTTY; ++ break; ++ } ++ ++ up(&bdev->bd_sem); ++ return ret; ++} ++ ++/** ++ * blk_trace_shutdown: - stop and cleanup trace structures ++ * @q: the request queue associated with the device ++ * ++ **/ ++void blk_trace_shutdown(request_queue_t *q) ++{ ++ blk_trace_startstop(q, 0); ++ blk_trace_remove(q); ++} ++ ++/* ++ * Average offset over two calls to sched_clock() with a gettimeofday() ++ * in the middle ++ */ ++static void blk_check_time(unsigned long long *t) ++{ ++ unsigned long long a, b; ++ struct timeval tv; ++ ++ a = sched_clock(); ++ do_gettimeofday(&tv); ++ b = sched_clock(); ++ ++ *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000; ++ *t -= (a + b) / 2; ++} ++ ++static void blk_trace_check_cpu_time(void *data) ++{ ++ unsigned long long *t; ++ int cpu = get_cpu(); ++ ++ t = &per_cpu(blk_trace_cpu_offset, cpu); ++ ++ /* ++ * Just call it twice, hopefully the second call will be cache hot ++ * and a little more precise ++ */ ++ blk_check_time(t); ++ blk_check_time(t); ++ ++ put_cpu(); ++} ++ ++/* ++ * Call blk_trace_check_cpu_time() on each CPU to calibrate our inter-CPU ++ * timings ++ */ ++static void blk_trace_calibrate_offsets(void) ++{ ++ unsigned long flags; ++ ++ smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1); ++ local_irq_save(flags); ++ blk_trace_check_cpu_time(NULL); ++ local_irq_restore(flags); ++} ++ ++static void blk_trace_set_ht_offsets(void) ++{ ++#if defined(CONFIG_SCHED_SMT) ++ int cpu, i; ++ ++ /* ++ * now make sure HT siblings have the same time offset ++ */ ++ preempt_disable(); ++ for_each_online_cpu(cpu) { ++ unsigned long long *cpu_off, *sibling_off; ++ ++ for_each_cpu_mask(i, cpu_sibling_map[cpu]) { ++ if (i == cpu) ++ continue; ++ ++ cpu_off = &per_cpu(blk_trace_cpu_offset, cpu); ++ sibling_off = &per_cpu(blk_trace_cpu_offset, i); ++ *sibling_off = *cpu_off; ++ } ++ } ++ preempt_enable(); ++#endif ++} ++ ++static __init int blk_trace_init(void) ++{ ++ mutex_init(&blk_tree_mutex); ++ blk_trace_calibrate_offsets(); ++ blk_trace_set_ht_offsets(); ++ ++ return 0; ++} ++ ++module_init(blk_trace_init); ++ +diff --git a/block/elevator.c b/block/elevator.c +index 24b702d..0c9fafe 100644 +--- a/block/elevator.c ++++ b/block/elevator.c +@@ -33,6 +33,7 @@ + #include + #include + #include ++#include + + #include + +@@ -315,6 +316,8 @@ void elv_insert(request_queue_t *q, stru + struct list_head *pos; + unsigned ordseq; + ++ blk_add_trace_rq(q, rq, BLK_TA_INSERT); ++ + rq->q = q; + + switch (where) { +@@ -481,6 +484,7 @@ struct request *elv_next_request(request + * not be passed by new incoming requests + */ + rq->flags |= REQ_STARTED; ++ blk_add_trace_rq(q, rq, BLK_TA_ISSUE); + } + + if (!q->boundary_rq || q->boundary_rq == rq) { +diff --git a/block/ioctl.c b/block/ioctl.c +index e110949..7acb56c 100644 +--- a/block/ioctl.c ++++ b/block/ioctl.c +@@ -5,6 +5,7 @@ + #include + #include + #include ++#include + #include + + static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg) +@@ -189,6 +190,11 @@ static int blkdev_locked_ioctl(struct fi + return put_ulong(arg, bdev->bd_inode->i_size >> 9); + case BLKGETSIZE64: + return put_u64(arg, bdev->bd_inode->i_size); ++ case BLKTRACESTART: ++ case BLKTRACESTOP: ++ case BLKTRACESETUP: ++ case BLKTRACETEARDOWN: ++ return blk_trace_ioctl(bdev, cmd, (char __user *) arg); + } + return -ENOIOCTLCMD; + } +diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c +index 03d9c82..41387f5 100644 +--- a/block/ll_rw_blk.c ++++ b/block/ll_rw_blk.c +@@ -28,6 +28,7 @@ + #include + #include + #include ++#include + + /* + * for max sense size +@@ -1551,8 +1552,10 @@ void blk_plug_device(request_queue_t *q) + if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)) + return; + +- if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) ++ if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) { + mod_timer(&q->unplug_timer, jiffies + q->unplug_delay); ++ blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG); ++ } + } + + EXPORT_SYMBOL(blk_plug_device); +@@ -1616,14 +1619,21 @@ static void blk_backing_dev_unplug(struc + /* + * devices don't necessarily have an ->unplug_fn defined + */ +- if (q->unplug_fn) ++ if (q->unplug_fn) { ++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, ++ q->rq.count[READ] + q->rq.count[WRITE]); ++ + q->unplug_fn(q); ++ } + } + + static void blk_unplug_work(void *data) + { + request_queue_t *q = data; + ++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, ++ q->rq.count[READ] + q->rq.count[WRITE]); ++ + q->unplug_fn(q); + } + +@@ -1631,6 +1641,9 @@ static void blk_unplug_timeout(unsigned + { + request_queue_t *q = (request_queue_t *)data; + ++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL, ++ q->rq.count[READ] + q->rq.count[WRITE]); ++ + kblockd_schedule_work(&q->unplug_work); + } + +@@ -1753,6 +1766,9 @@ void blk_cleanup_queue(request_queue_t * + if (q->queue_tags) + __blk_queue_free_tags(q); + ++ if (q->blk_trace) ++ blk_trace_shutdown(q); ++ + kmem_cache_free(requestq_cachep, q); + } + +@@ -2104,6 +2120,8 @@ rq_starved: + + rq_init(q, rq); + rq->rl = rl; ++ ++ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ); + out: + return rq; + } +@@ -2132,6 +2150,8 @@ static struct request *get_request_wait( + if (!rq) { + struct io_context *ioc; + ++ blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); ++ + __generic_unplug_device(q); + spin_unlock_irq(q->queue_lock); + io_schedule(); +@@ -2185,6 +2205,8 @@ EXPORT_SYMBOL(blk_get_request); + */ + void blk_requeue_request(request_queue_t *q, struct request *rq) + { ++ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); ++ + if (blk_rq_tagged(rq)) + blk_queue_end_tag(q, rq); + +@@ -2819,6 +2841,8 @@ static int __make_request(request_queue_ + if (!q->back_merge_fn(q, req, bio)) + break; + ++ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); ++ + req->biotail->bi_next = bio; + req->biotail = bio; + req->nr_sectors = req->hard_nr_sectors += nr_sectors; +@@ -2834,6 +2858,8 @@ static int __make_request(request_queue_ + if (!q->front_merge_fn(q, req, bio)) + break; + ++ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); ++ + bio->bi_next = req->bio; + req->bio = bio; + +@@ -2951,6 +2977,7 @@ void generic_make_request(struct bio *bi + request_queue_t *q; + sector_t maxsector; + int ret, nr_sectors = bio_sectors(bio); ++ dev_t old_dev; + + might_sleep(); + /* Test device or partition size, when known. */ +@@ -2977,6 +3004,8 @@ void generic_make_request(struct bio *bi + * NOTE: we don't repeat the blk_size check for each new device. + * Stacking drivers are expected to know what they are doing. + */ ++ maxsector = -1; ++ old_dev = 0; + do { + char b[BDEVNAME_SIZE]; + +@@ -3009,6 +3038,15 @@ end_io: + */ + blk_partition_remap(bio); + ++ if (maxsector != -1) ++ blk_add_trace_remap(q, bio, old_dev, bio->bi_sector, ++ maxsector); ++ ++ blk_add_trace_bio(q, bio, BLK_TA_QUEUE); ++ ++ maxsector = bio->bi_sector; ++ old_dev = bio->bi_bdev->bd_dev; ++ + ret = q->make_request_fn(q, bio); + } while (ret); + } +@@ -3128,6 +3166,8 @@ static int __end_that_request_first(stru + int total_bytes, bio_nbytes, error, next_idx = 0; + struct bio *bio; + ++ blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE); ++ + /* + * extend uptodate bool to allow < 0 value to be direct io error + */ +diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c +index 0d65394..234048e 100644 +--- a/drivers/block/cciss.c ++++ b/drivers/block/cciss.c +@@ -38,6 +38,7 @@ + #include + #include + #include ++#include + #include + #include + +@@ -2331,6 +2332,7 @@ static inline void complete_command( ctl + + cmd->rq->completion_data = cmd; + cmd->rq->errors = status; ++ blk_add_trace_rq(cmd->rq->q, cmd->rq, BLK_TA_COMPLETE); + blk_complete_request(cmd->rq); + } + +diff --git a/drivers/md/dm.c b/drivers/md/dm.c +index e9adeb9..c8f3aa2 100644 +--- a/drivers/md/dm.c ++++ b/drivers/md/dm.c +@@ -17,6 +17,7 @@ + #include + #include + #include ++#include + + static const char *_name = DM_NAME; + +@@ -334,6 +335,8 @@ static void dec_pending(struct dm_io *io + /* nudge anyone waiting on suspend queue */ + wake_up(&io->md->wait); + ++ blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE); ++ + bio_endio(io->bio, io->bio->bi_size, io->error); + free_io(io->md, io); + } +@@ -392,6 +395,7 @@ static void __map_bio(struct dm_target * + struct target_io *tio) + { + int r; ++ sector_t sector; + + /* + * Sanity checks. +@@ -407,10 +411,17 @@ static void __map_bio(struct dm_target * + * this io. + */ + atomic_inc(&tio->io->io_count); ++ sector = clone->bi_sector; + r = ti->type->map(ti, clone, &tio->info); +- if (r > 0) ++ if (r > 0) { + /* the bio has been remapped so dispatch it */ ++ ++ blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, ++ tio->io->bio->bi_bdev->bd_dev, sector, ++ clone->bi_sector); ++ + generic_make_request(clone); ++ } + + else if (r < 0) { + /* error the io and bail out */ +diff --git a/fs/bio.c b/fs/bio.c +index 1f3bb50..0dd0d81 100644 +--- a/fs/bio.c ++++ b/fs/bio.c +@@ -25,6 +25,7 @@ + #include + #include + #include ++#include + #include /* for struct sg_iovec */ + + #define BIO_POOL_SIZE 256 +@@ -1095,6 +1096,9 @@ struct bio_pair *bio_split(struct bio *b + if (!bp) + return bp; + ++ blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi, ++ bi->bi_sector + first_sectors); ++ + BUG_ON(bi->bi_vcnt != 1); + BUG_ON(bi->bi_idx != 0); + atomic_set(&bp->cnt, 3); +diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c +index 057e602..893d600 100644 +--- a/fs/compat_ioctl.c ++++ b/fs/compat_ioctl.c +@@ -72,6 +72,7 @@ + #include + #include + #include ++#include + + #include /* siocdevprivate_ioctl */ + #include +diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h +index 860e7a4..266ce9d 100644 +--- a/include/linux/blkdev.h ++++ b/include/linux/blkdev.h +@@ -22,6 +22,7 @@ typedef struct request_queue request_que + struct elevator_queue; + typedef struct elevator_queue elevator_t; + struct request_pm_state; ++struct blk_trace; + + #define BLKDEV_MIN_RQ 4 + #define BLKDEV_MAX_RQ 128 /* Default maximum */ +@@ -416,6 +417,8 @@ struct request_queue + unsigned int sg_reserved_size; + int node; + ++ struct blk_trace *blk_trace; ++ + /* + * reserved for flush operations + */ +diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h +new file mode 100644 +index 0000000..86479af +--- /dev/null ++++ b/include/linux/blktrace_api.h +@@ -0,0 +1,277 @@ ++#ifndef BLKTRACE_H ++#define BLKTRACE_H ++ ++#include ++#include ++#include ++ ++/* ++ * Trace categories ++ */ ++enum blktrace_cat { ++ BLK_TC_READ = 1 << 0, /* reads */ ++ BLK_TC_WRITE = 1 << 1, /* writes */ ++ BLK_TC_BARRIER = 1 << 2, /* barrier */ ++ BLK_TC_SYNC = 1 << 3, /* barrier */ ++ BLK_TC_QUEUE = 1 << 4, /* queueing/merging */ ++ BLK_TC_REQUEUE = 1 << 5, /* requeueing */ ++ BLK_TC_ISSUE = 1 << 6, /* issue */ ++ BLK_TC_COMPLETE = 1 << 7, /* completions */ ++ BLK_TC_FS = 1 << 8, /* fs requests */ ++ BLK_TC_PC = 1 << 9, /* pc requests */ ++ BLK_TC_NOTIFY = 1 << 10, /* special message */ ++ ++ BLK_TC_END = 1 << 15, /* only 16-bits, reminder */ ++}; ++ ++#define BLK_TC_SHIFT (16) ++#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT) ++ ++/* ++ * Basic trace actions ++ */ ++enum blktrace_act { ++ __BLK_TA_QUEUE = 1, /* queued */ ++ __BLK_TA_BACKMERGE, /* back merged to existing rq */ ++ __BLK_TA_FRONTMERGE, /* front merge to existing rq */ ++ __BLK_TA_GETRQ, /* allocated new request */ ++ __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */ ++ __BLK_TA_REQUEUE, /* request requeued */ ++ __BLK_TA_ISSUE, /* sent to driver */ ++ __BLK_TA_COMPLETE, /* completed by driver */ ++ __BLK_TA_PLUG, /* queue was plugged */ ++ __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */ ++ __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */ ++ __BLK_TA_INSERT, /* insert request */ ++ __BLK_TA_SPLIT, /* bio was split */ ++ __BLK_TA_BOUNCE, /* bio was bounced */ ++ __BLK_TA_REMAP, /* bio was remapped */ ++}; ++ ++/* ++ * Trace actions in full. Additionally, read or write is masked ++ */ ++#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE)) ++#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE)) ++#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE)) ++#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE)) ++#define BLK_TA_SPLIT (__BLK_TA_SPLIT) ++#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE) ++#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE)) ++ ++#define BLK_IO_TRACE_MAGIC 0x65617400 ++#define BLK_IO_TRACE_VERSION 0x07 ++ ++/* ++ * The trace itself ++ */ ++struct blk_io_trace { ++ u32 magic; /* MAGIC << 8 | version */ ++ u32 sequence; /* event number */ ++ u64 time; /* in microseconds */ ++ u64 sector; /* disk offset */ ++ u32 bytes; /* transfer length */ ++ u32 action; /* what happened */ ++ u32 pid; /* who did it */ ++ u32 device; /* device number */ ++ u32 cpu; /* on what cpu did it happen */ ++ u16 error; /* completion error */ ++ u16 pdu_len; /* length of data after this trace */ ++}; ++ ++/* ++ * The remap event ++ */ ++struct blk_io_trace_remap { ++ u32 device; ++ u32 __pad; ++ u64 sector; ++}; ++ ++enum { ++ Blktrace_setup = 1, ++ Blktrace_running, ++ Blktrace_stopped, ++}; ++ ++struct blk_trace { ++ int trace_state; ++ struct rchan *rchan; ++ unsigned long *sequence; ++ u16 act_mask; ++ u64 start_lba; ++ u64 end_lba; ++ u32 pid; ++ u32 dev; ++ struct dentry *dir; ++ struct dentry *dropped_file; ++ atomic_t dropped; ++}; ++ ++/* ++ * User setup structure passed with BLKTRACESTART ++ */ ++struct blk_user_trace_setup { ++ char name[BDEVNAME_SIZE]; /* output */ ++ u16 act_mask; /* input */ ++ u32 buf_size; /* input */ ++ u32 buf_nr; /* input */ ++ u64 start_lba; ++ u64 end_lba; ++ u32 pid; ++}; ++ ++#if defined(CONFIG_BLK_DEV_IO_TRACE) ++extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *); ++extern void blk_trace_shutdown(request_queue_t *); ++extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *); ++ ++/** ++ * 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 inline void blk_add_trace_rq(struct request_queue *q, struct request *rq, ++ u32 what) ++{ ++ struct blk_trace *bt = q->blk_trace; ++ int rw = rq->flags & 0x07; ++ ++ if (likely(!bt)) ++ return; ++ ++ 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); ++ } ++} ++ ++/** ++ * 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 inline 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); ++} ++ ++/** ++ * blk_add_trace_generic - Add a trace for a generic action ++ * @q: queue the io is for ++ * @bio: the source bio ++ * @rw: the data direction ++ * @what: the action ++ * ++ * Description: ++ * Records a simple trace ++ * ++ **/ ++static inline void blk_add_trace_generic(struct request_queue *q, ++ struct bio *bio, int rw, u32 what) ++{ ++ struct blk_trace *bt = q->blk_trace; ++ ++ if (likely(!bt)) ++ return; ++ ++ if (bio) ++ blk_add_trace_bio(q, bio, what); ++ else ++ __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL); ++} ++ ++/** ++ * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload ++ * @q: queue the io is for ++ * @what: the action ++ * @bio: the source bio ++ * @pdu: the integer payload ++ * ++ * Description: ++ * Adds a trace with some integer payload. This might be an unplug ++ * option given as the action, with the depth at unplug time given ++ * as the payload ++ * ++ **/ ++static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what, ++ struct bio *bio, unsigned int pdu) ++{ ++ struct blk_trace *bt = q->blk_trace; ++ u64 rpdu = cpu_to_be64(pdu); ++ ++ if (likely(!bt)) ++ return; ++ ++ if (bio) ++ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu); ++ else ++ __blk_add_trace(bt, 0, 0, 0, what, 0, 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 inline 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.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); ++} ++ ++#else /* !CONFIG_BLK_DEV_IO_TRACE */ ++#define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY) ++#define blk_trace_shutdown(q) do { } while (0) ++#define blk_add_trace_rq(q, rq, what) do { } while (0) ++#define blk_add_trace_bio(q, rq, what) do { } while (0) ++#define blk_add_trace_generic(q, rq, rw, what) do { } while (0) ++#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0) ++#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0) ++#endif /* CONFIG_BLK_DEV_IO_TRACE */ ++ ++#endif +diff --git a/include/linux/compat_ioctl.h b/include/linux/compat_ioctl.h +index 8fad50f..a3ed64b 100644 +--- a/include/linux/compat_ioctl.h ++++ b/include/linux/compat_ioctl.h +@@ -97,6 +97,10 @@ COMPATIBLE_IOCTL(BLKRRPART) + COMPATIBLE_IOCTL(BLKFLSBUF) + COMPATIBLE_IOCTL(BLKSECTSET) + COMPATIBLE_IOCTL(BLKSSZGET) ++COMPATIBLE_IOCTL(BLKTRACESTART) ++COMPATIBLE_IOCTL(BLKTRACESTOP) ++COMPATIBLE_IOCTL(BLKTRACESETUP) ++COMPATIBLE_IOCTL(BLKTRACETEARDOWN) + ULONG_IOCTL(BLKRASET) + ULONG_IOCTL(BLKFRASET) + /* RAID */ +diff --git a/include/linux/fs.h b/include/linux/fs.h +index e059da9..c7a63cd 100644 +--- a/include/linux/fs.h ++++ b/include/linux/fs.h +@@ -196,6 +196,10 @@ extern int dir_notify_enable; + #define BLKBSZGET _IOR(0x12,112,size_t) + #define BLKBSZSET _IOW(0x12,113,size_t) + #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */ ++#define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup) ++#define BLKTRACESTART _IO(0x12,116) ++#define BLKTRACESTOP _IO(0x12,117) ++#define BLKTRACETEARDOWN _IO(0x12,118) + + #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ + #define FIBMAP _IO(0x00,1) /* bmap access */ +diff --git a/include/linux/sched.h b/include/linux/sched.h +index b6f51e3..d9d465b 100644 +--- a/include/linux/sched.h ++++ b/include/linux/sched.h +@@ -705,6 +705,7 @@ struct task_struct { + prio_array_t *array; + + unsigned short ioprio; ++ unsigned int btrace_seq; + + unsigned long sleep_avg; + unsigned long long timestamp, last_ran; +diff --git a/kernel/fork.c b/kernel/fork.c +index 8e88b37..60f838f 100644 +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -179,6 +179,7 @@ static struct task_struct *dup_task_stru + /* One for us, one for whoever does the "release_task()" (usually parent) */ + atomic_set(&tsk->usage,2); + atomic_set(&tsk->fs_excl, 0); ++ tsk->btrace_seq = 0; + return tsk; + } + +diff --git a/mm/highmem.c b/mm/highmem.c +index ce2e7e8..d0ea1ee 100644 +--- a/mm/highmem.c ++++ b/mm/highmem.c +@@ -26,6 +26,7 @@ + #include + #include + #include ++#include + #include + + static mempool_t *page_pool, *isa_page_pool; +@@ -483,6 +484,8 @@ void blk_queue_bounce(request_queue_t *q + pool = isa_page_pool; + } + ++ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE); ++ + /* + * slow path + */