diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/Kconfig | 24 | ||||
| -rw-r--r-- | block/Makefile | 1 | ||||
| -rw-r--r-- | block/blktrace.c | 1538 |
3 files changed, 0 insertions, 1563 deletions
diff --git a/block/Kconfig b/block/Kconfig index 7cdaa1d72252..e7d12782bcfb 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -44,30 +44,6 @@ config LBD If unsure, say N. -config BLK_DEV_IO_TRACE - bool "Support for tracing block io actions" - depends on SYSFS - select RELAY - select DEBUG_FS - select TRACEPOINTS - select TRACING - select STACKTRACE - 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 userspace - support tools needed), fetch the blktrace tools from: - - git://git.kernel.dk/blktrace.git - - Tracing also is possible using the ftrace interface, e.g.: - - echo 1 > /sys/block/sda/sda1/trace/enable - echo blk > /sys/kernel/debug/tracing/current_tracer - cat /sys/kernel/debug/tracing/trace_pipe - - If unsure, say N. - config BLK_DEV_BSG bool "Block layer SG support v4 (EXPERIMENTAL)" depends on EXPERIMENTAL diff --git a/block/Makefile b/block/Makefile index bfe73049f939..e9fa4dd690f2 100644 --- a/block/Makefile +++ b/block/Makefile @@ -13,6 +13,5 @@ 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 obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o diff --git a/block/blktrace.c b/block/blktrace.c deleted file mode 100644 index ca6d32061e4f..000000000000 --- a/block/blktrace.c +++ /dev/null @@ -1,1538 +0,0 @@ -/* - * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - * - */ -#include <linux/kernel.h> -#include <linux/blkdev.h> -#include <linux/blktrace_api.h> -#include <linux/percpu.h> -#include <linux/init.h> -#include <linux/mutex.h> -#include <linux/debugfs.h> -#include <linux/time.h> -#include <trace/block.h> -#include <linux/uaccess.h> -#include <../kernel/trace/trace_output.h> - -static unsigned int blktrace_seq __read_mostly = 1; - -static struct trace_array *blk_tr; -static int __read_mostly blk_tracer_enabled; - -/* Select an alternative, minimalistic output than the original one */ -#define TRACE_BLK_OPT_CLASSIC 0x1 - -static struct tracer_opt blk_tracer_opts[] = { - /* Default disable the minimalistic output */ - { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, - { } -}; - -static struct tracer_flags blk_tracer_flags = { - .val = 0, - .opts = blk_tracer_opts, -}; - -/* 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. - */ -static void trace_note(struct blk_trace *bt, pid_t pid, int action, - const void *data, size_t len) -{ - struct blk_io_trace *t; - - if (!bt->rchan) - return; - - t = relay_reserve(bt->rchan, sizeof(*t) + len); - if (t) { - const int cpu = smp_processor_id(); - - t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; - t->time = ktime_to_ns(ktime_get()); - t->device = bt->dev; - t->action = action; - t->pid = pid; - t->cpu = cpu; - t->pdu_len = len; - memcpy((void *) t + sizeof(*t), data, len); - } -} - -/* - * 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) -{ - tsk->btrace_seq = blktrace_seq; - trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); -} - -static void trace_note_time(struct blk_trace *bt) -{ - struct timespec now; - unsigned long flags; - u32 words[2]; - - getnstimeofday(&now); - words[0] = now.tv_sec; - words[1] = now.tv_nsec; - - local_irq_save(flags); - trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); - local_irq_restore(flags); -} - -void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) -{ - int n; - va_list args; - unsigned long flags; - char *buf; - - if (blk_tr) { - va_start(args, fmt); - ftrace_vprintk(fmt, args); - va_end(args); - return; - } - - if (!bt->msg_data) - return; - - local_irq_save(flags); - buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); - va_start(args, fmt); - n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); - va_end(args); - - trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); - local_irq_restore(flags); -} -EXPORT_SYMBOL_GPL(__trace_note_message); - -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) }; - -/* The ilog2() calls fall out because they're constant */ -#define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \ - (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name)) - -/* - * The worker for the various blk_add_trace*() types. Fills out a - * blk_io_trace structure and places it in a per-cpu subbuffer. - */ -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; - struct ring_buffer_event *event = NULL; - struct blk_io_trace *t; - unsigned long flags = 0; - unsigned long *sequence; - pid_t pid; - int cpu, pc = 0; - - if (unlikely(bt->trace_state != Blktrace_running || - !blk_tracer_enabled)) - return; - - what |= ddir_act[rw & WRITE]; - what |= MASK_TC_BIT(rw, BARRIER); - what |= MASK_TC_BIT(rw, SYNC); - what |= MASK_TC_BIT(rw, AHEAD); - what |= MASK_TC_BIT(rw, META); - what |= MASK_TC_BIT(rw, DISCARD); - - pid = tsk->pid; - if (unlikely(act_log_check(bt, what, sector, pid))) - return; - cpu = raw_smp_processor_id(); - - if (blk_tr) { - tracing_record_cmdline(current); - - pc = preempt_count(); - event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK, - sizeof(*t) + pdu_len, - 0, pc); - if (!event) - return; - t = ring_buffer_event_data(event); - goto record_it; - } - - /* - * A word about the locking here - we disable interrupts to reserve - * some space in the relay per-cpu buffer, to prevent an irq - * from coming in and stepping on our toes. - */ - 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) { - sequence = per_cpu_ptr(bt->sequence, cpu); - - t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; - t->sequence = ++(*sequence); - t->time = ktime_to_ns(ktime_get()); -record_it: - /* - * These two are not needed in ftrace as they are in the - * generic trace_entry, filled by tracing_generic_entry_update, - * but for the trace_event->bin() synthesizer benefit we do it - * here too. - */ - t->cpu = cpu; - t->pid = pid; - - t->sector = sector; - t->bytes = bytes; - t->action = what; - t->device = bt->dev; - t->error = error; - t->pdu_len = pdu_len; - - if (pdu_len) - memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); - - if (blk_tr) { - trace_buffer_unlock_commit(blk_tr, event, 0, pc); - return; - } - } - - local_irq_restore(flags); -} - -static struct dentry *blk_tree_root; -static DEFINE_MUTEX(blk_tree_mutex); - -static void blk_trace_cleanup(struct blk_trace *bt) -{ - debugfs_remove(bt->msg_file); - debugfs_remove(bt->dropped_file); - relay_close(bt->rchan); - 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) -{ - 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; -} -EXPORT_SYMBOL_GPL(blk_trace_remove); - -static int blk_dropped_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - 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 const struct file_operations blk_dropped_fops = { - .owner = THIS_MODULE, - .open = blk_dropped_open, - .read = blk_dropped_read, -}; - -static int blk_msg_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - return 0; -} - -static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, - size_t count, loff_t *ppos) -{ - char *msg; - struct blk_trace *bt; - - if (count > BLK_TN_MAX_MSG) - return -EINVAL; - - msg = kmalloc(count, GFP_KERNEL); - if (msg == NULL) - return -ENOMEM; - - if (copy_from_user(msg, buffer, count)) { - kfree(msg); - return -EFAULT; - } - - bt = filp->private_data; - __trace_note_message(bt, "%s", msg); - kfree(msg); - - return count; -} - -static const struct file_operations blk_msg_fops = { - .owner = THIS_MODULE, - .open = blk_msg_open, - .write = blk_msg_write, -}; - -/* - * 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 int blk_remove_buf_file_callback(struct dentry *dentry) -{ - struct dentry *parent = dentry->d_parent; - debugfs_remove(dentry); - - /* - * this will fail for all but the last file, but that is ok. what we - * care about is the top level buts->name directory going away, when - * the last trace file is gone. Then we don't have to rmdir() that - * manually on trace stop, so it nicely solves the issue with - * force killing of running traces. - */ - - debugfs_remove(parent); - return 0; -} - -static struct dentry *blk_create_buf_file_callback(const char *filename, - struct dentry *parent, - int mode, - struct rchan_buf *buf, - int *is_global) -{ - return debugfs_create_file(filename, mode, parent, buf, - &relay_file_operations); -} - -static struct rchan_callbacks blk_relay_callbacks = { - .subbuf_start = blk_subbuf_start_callback, - .create_buf_file = blk_create_buf_file_callback, - .remove_buf_file = blk_remove_buf_file_callback, -}; - -/* - * Setup everything required to start tracing - */ -int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - struct blk_user_trace_setup *buts) -{ - struct blk_trace *old_bt, *bt = NULL; - struct dentry *dir = NULL; - int ret, i; - - if (!buts->buf_size || !buts->buf_nr) - return -EINVAL; - - strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); - buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; - - /* - * 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] = '_'; - - ret = -ENOMEM; - bt = kzalloc(sizeof(*bt), GFP_KERNEL); - if (!bt) - goto err; - - bt->sequence = alloc_percpu(unsigned long); - if (!bt->sequence) - goto err; - - bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG); - if (!bt->msg_data) - goto err; - - ret = -ENOENT; - - if (!blk_tree_root) { - blk_tree_root = debugfs_create_dir("block", NULL); - if (!blk_tree_root) - return -ENOMEM; - } - - dir = debugfs_create_dir(buts->name, blk_tree_root); - - if (!dir) - goto err; - - bt->dir = dir; - bt->dev = dev; - atomic_set(&bt->dropped, 0); - - ret = -EIO; - bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, - &blk_dropped_fops); - if (!bt->dropped_file) - goto err; - - bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); - if (!bt->msg_file) - goto err; - - bt->rchan = relay_open("trace", dir, buts->buf_size, - buts->buf_nr, &blk_relay_callbacks, bt); - if (!bt->rchan) - goto err; - - 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; - - 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) { - (void) xchg(&q->blk_trace, old_bt); - goto err; - } - - return 0; -probe_err: - atomic_dec(&blk_probes_ref); - mutex_unlock(&blk_probe_mutex); -err: - if (bt) { - if (bt->msg_file) - debugfs_remove(bt->msg_file); - if (bt->dropped_file) - debugfs_remove(bt->dropped_file); - free_percpu(bt->sequence); - free_percpu(bt->msg_data); - if (bt->rchan) - relay_close(bt->rchan); - kfree(bt); - } - return ret; -} - -int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - char __user *arg) -{ - struct blk_user_trace_setup buts; - int ret; - - ret = copy_from_user(&buts, arg, sizeof(buts)); - if (ret) - return -EFAULT; - - ret = do_blk_trace_setup(q, name, dev, &buts); - if (ret) - return ret; - - if (copy_to_user(arg, &buts, sizeof(buts))) - return -EFAULT; - - return 0; -} -EXPORT_SYMBOL_GPL(blk_trace_setup); - -int blk_trace_startstop(struct request_queue *q, int start) -{ - int ret; - struct blk_trace *bt = q->blk_trace; - - if (bt == 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; - - trace_note_time(bt); - ret = 0; - } - } else { - if (bt->trace_state == Blktrace_running) { - bt->trace_state = Blktrace_stopped; - relay_flush(bt->rchan); - ret = 0; - } - } - - return ret; -} -EXPORT_SYMBOL_GPL(blk_trace_startstop); - -/** - * 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) -{ - struct request_queue *q; - int ret, start = 0; - char b[BDEVNAME_SIZE]; - - q = bdev_get_queue(bdev); - if (!q) - return -ENXIO; - - mutex_lock(&bdev->bd_mutex); - - switch (cmd) { - case BLKTRACESETUP: - bdevname(bdev, b); - ret = blk_trace_setup(q, b, bdev->bd_dev, 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; - } - - mutex_unlock(&bdev->bd_mutex); - return ret; -} - -/** - * blk_trace_shutdown: - stop and cleanup trace structures - * @q: the request queue associated with the device - * - **/ -void blk_trace_shutdown(struct request_queue *q) -{ - if (q->blk_trace) { - blk_trace_startstop(q, 0); - 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(); -} - -/* - * struct blk_io_tracer formatting routines - */ - -static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) -{ - int i = 0; - - if (t->action & BLK_TC_DISCARD) - rwbs[i++] = 'D'; - else if (t->action & BLK_TC_WRITE) - rwbs[i++] = 'W'; - else if (t->bytes) - rwbs[i++] = 'R'; - else - rwbs[i++] = 'N'; - - if (t->action & BLK_TC_AHEAD) - rwbs[i++] = 'A'; - if (t->action & BLK_TC_BARRIER) - rwbs[i++] = 'B'; - if (t->action & BLK_TC_SYNC) - rwbs[i++] = 'S'; - if (t->action & BLK_TC_META) - rwbs[i++] = 'M'; - - rwbs[i] = '\0'; -} - -static inline -const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) -{ - return (const struct blk_io_trace *)ent; -} - -static inline const void *pdu_start(const struct trace_entry *ent) -{ - return te_blk_io_trace(ent) + 1; -} - -static inline u32 t_sec(const struct trace_entry *ent) -{ - return te_blk_io_trace(ent)->bytes >> 9; -} - -static inline unsigned long long t_sector(const struct trace_entry *ent) -{ - return te_blk_io_trace(ent)->sector; -} - -static inline __u16 t_error(const struct trace_entry *ent) -{ - return te_blk_io_trace(ent)->sector; -} - -static __u64 get_pdu_int(const struct trace_entry *ent) -{ - const __u64 *val = pdu_start(ent); - return be64_to_cpu(*val); -} - -static void get_pdu_remap(const struct trace_entry *ent, - struct blk_io_trace_remap *r) -{ - const struct blk_io_trace_remap *__r = pdu_start(ent); - __u64 sector = __r->sector; - - r->device = be32_to_cpu(__r->device); - r->device_from = be32_to_cpu(__r->device_from); - r->sector = be64_to_cpu(sector); -} - -static int blk_log_action_iter(struct trace_iterator *iter, const char *act) -{ - char rwbs[6]; - unsigned long long ts = ns2usecs(iter->ts); - unsigned long usec_rem = do_div(ts, USEC_PER_SEC); - unsigned secs = (unsigned long)ts; - const struct trace_entry *ent = iter->ent; - const struct blk_io_trace *t = (const struct blk_io_trace *)ent; - - fill_rwbs(rwbs, t); - - return trace_seq_printf(&iter->seq, - "%3d,%-3d %2d %5d.%06lu %5u %2s %3s ", - MAJOR(t->device), MINOR(t->device), iter->cpu, - secs, usec_rem, ent->pid, act, rwbs); -} - -static int blk_log_action_seq(struct trace_seq *s, const struct blk_io_trace *t, - const char *act) -{ - char rwbs[6]; - fill_rwbs(rwbs, t); - return trace_seq_printf(s, "%3d,%-3d %2s %3s ", - MAJOR(t->device), MINOR(t->device), act, rwbs); -} - -static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent) -{ - const char *cmd = trace_find_cmdline(ent->pid); - - if (t_sec(ent)) - return trace_seq_printf(s, "%llu + %u [%s]\n", - t_sector(ent), t_sec(ent), cmd); - return trace_seq_printf(s, "[%s]\n", cmd); -} - -static int blk_log_with_error(struct trace_seq *s, - const struct trace_entry *ent) -{ - if (t_sec(ent)) - return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent), - t_sec(ent), t_error(ent)); - return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent)); -} - -static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent) -{ - struct blk_io_trace_remap r = { .device = 0, }; - - get_pdu_remap(ent, &r); - return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", - t_sector(ent), - t_sec(ent), MAJOR(r.device), MINOR(r.device), - (unsigned long long)r.sector); -} - -static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent) -{ - return trace_seq_printf(s, "[%s]\n", trace_find_cmdline(ent->pid)); -} - -static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent) -{ - return trace_seq_printf(s, "[%s] %llu\n", trace_find_cmdline(ent->pid), - get_pdu_int(ent)); -} - -static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent) -{ - return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), - get_pdu_int(ent), trace_find_cmdline(ent->pid)); -} - -/* - * struct tracer operations - */ - -static void blk_tracer_print_header(struct seq_file *m) -{ - if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) - return; - seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" - "# | | | | | |\n"); -} - -static void blk_tracer_start(struct trace_array *tr) -{ - mutex_lock(&blk_probe_mutex); - if (atomic_add_return(1, &blk_probes_ref) == 1) - if (blk_register_tracepoints()) - atomic_dec(&blk_probes_ref); - mutex_unlock(&blk_probe_mutex); - trace_flags &= ~TRACE_ITER_CONTEXT_INFO; -} - -static int blk_tracer_init(struct trace_array *tr) -{ - blk_tr = tr; - blk_tracer_start(tr); - mutex_lock(&blk_probe_mutex); - blk_tracer_enabled++; - mutex_unlock(&blk_probe_mutex); - return 0; -} - -static void blk_tracer_stop(struct trace_array *tr) -{ - trace_flags |= TRACE_ITER_CONTEXT_INFO; - mutex_lock(&blk_probe_mutex); - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); - mutex_unlock(&blk_probe_mutex); -} - -static void blk_tracer_reset(struct trace_array *tr) -{ - if (!atomic_read(&blk_probes_ref)) - return; - - mutex_lock(&blk_probe_mutex); - blk_tracer_enabled--; - WARN_ON(blk_tracer_enabled < 0); - mutex_unlock(&blk_probe_mutex); - - blk_tracer_stop(tr); -} - -static struct { - const char *act[2]; - int (*print)(struct trace_seq *s, const struct trace_entry *ent); -} what2act[] __read_mostly = { - [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, - [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, - [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, - [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, - [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, - [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, - [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, - [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, - [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, - [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, - [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, - [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, - [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, - [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, - [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, -}; - -static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, - int flags) -{ - struct trace_seq *s = &iter->seq; - const struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; - const u16 what = t->action & ((1 << BLK_TC_SHIFT) - 1); - int ret; - - if (!trace_print_context(iter)) - return TRACE_TYPE_PARTIAL_LINE; - - if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) - ret = trace_seq_printf(s, "Bad pc action %x\n", what); - else { - const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); - ret = blk_log_action_seq(s, t, what2act[what].act[long_act]); - if (ret) - ret = what2act[what].print(s, iter->ent); - } - - return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; -} - -static int blk_trace_synthesize_old_trace(struct trace_iterator *iter) -{ - struct trace_seq *s = &iter->seq; - struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; - const int offset = offsetof(struct blk_io_trace, sector); - struct blk_io_trace old = { - .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, - .time = ns2usecs(iter->ts), - }; - - if (!trace_seq_putmem(s, &old, offset)) - return 0; - return trace_seq_putmem(s, &t->sector, - sizeof(old) - offset + t->pdu_len); -} - -static enum print_line_t -blk_trace_event_print_binary(struct trace_iterator *iter, int flags) -{ - return blk_trace_synthesize_old_trace(iter) ? - TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; -} - -static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) -{ - const struct blk_io_trace *t; - u16 what; - int ret; - - if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) - return TRACE_TYPE_UNHANDLED; - - t = (const struct blk_io_trace *)iter->ent; - what = t->action & ((1 << BLK_TC_SHIFT) - 1); - - if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) - ret = trace_seq_printf(&iter->seq, "Bad pc action %x\n", what); - else { - const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); - ret = blk_log_action_iter(iter, what2act[what].act[long_act]); - if (ret) - ret = what2act[what].print(&iter->seq, iter->ent); - } - - return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; -} - -static struct tracer blk_tracer __read_mostly = { - .name = "blk", - .init = blk_tracer_init, - .reset = blk_tracer_reset, - .start = blk_tracer_start, - .stop = blk_tracer_stop, - .print_header = blk_tracer_print_header, - .print_line = blk_tracer_print_line, - .flags = &blk_tracer_flags, -}; - -static struct trace_event trace_blk_event = { - .type = TRACE_BLK, - .trace = blk_trace_event_print, - .latency_trace = blk_trace_event_print, - .binary = blk_trace_event_print_binary, -}; - -static int __init init_blk_tracer(void) -{ - if (!register_ftrace_event(&trace_blk_event)) { - pr_warning("Warning: could not register block events\n"); - return 1; - } - - if (register_tracer(&blk_tracer) != 0) { - pr_warning("Warning: could not register the block tracer\n"); - unregister_ftrace_event(&trace_blk_event); - return 1; - } - - return 0; -} - -device_initcall(init_blk_tracer); - -static int blk_trace_remove_queue(struct request_queue *q) -{ - struct blk_trace *bt; - - bt = xchg(&q->blk_trace, NULL); - if (bt == NULL) - return -EINVAL; - - kfree(bt); - return 0; -} - -/* - * Setup everything required to start tracing - */ -static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) -{ - struct blk_trace *old_bt, *bt = NULL; - int ret; - - ret = -ENOMEM; - bt = kzalloc(sizeof(*bt), GFP_KERNEL); - if (!bt) - goto err; - - bt->dev = dev; - bt->act_mask = (u16)-1; - bt->end_lba = -1ULL; - bt->trace_state = Blktrace_running; - - old_bt = xchg(&q->blk_trace, bt); - if (old_bt != NULL) { - (void)xchg(&q->blk_trace, old_bt); - kfree(bt); - ret = -EBUSY; - } - return 0; -err: - return ret; -} - -/* - * sysfs interface to enable and configure tracing - */ - -static ssize_t sysfs_blk_trace_enable_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct hd_struct *p = dev_to_part(dev); - struct block_device *bdev; - ssize_t ret = -ENXIO; - - lock_kernel(); - bdev = bdget(part_devt(p)); - if (bdev != NULL) { - struct request_queue *q = bdev_get_queue(bdev); - - if (q != NULL) { - mutex_lock(&bdev->bd_mutex); - ret = sprintf(buf, "%u\n", !!q->blk_trace); - mutex_unlock(&bdev->bd_mutex); - } - - bdput(bdev); - } - - unlock_kernel(); - return ret; -} - -static ssize_t sysfs_blk_trace_enable_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct block_device *bdev; - struct request_queue *q; - struct hd_struct *p; - int value; - ssize_t ret = -ENXIO; - - if (count == 0 || sscanf(buf, "%d", &value) != 1) - goto out; - - lock_kernel(); - p = dev_to_part(dev); - bdev = bdget(part_devt(p)); - if (bdev == NULL) - goto out_unlock_kernel; - - q = bdev_get_queue(bdev); - if (q == NULL) - goto out_bdput; - - mutex_lock(&bdev->bd_mutex); - if (value) - ret = blk_trace_setup_queue(q, bdev->bd_dev); - else - ret = blk_trace_remove_queue(q); - mutex_unlock(&bdev->bd_mutex); - - if (ret == 0) - ret = count; -out_bdput: - bdput(bdev); -out_unlock_kernel: - unlock_kernel(); -out: - return ret; -} - -static ssize_t sysfs_blk_trace_attr_show(struct device *dev, - struct device_attribute *attr, - char *buf); -static ssize_t sysfs_blk_trace_attr_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count); -#define BLK_TRACE_DEVICE_ATTR(_name) \ - DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ - sysfs_blk_trace_attr_show, \ - sysfs_blk_trace_attr_store) - -static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, - sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_store); -static BLK_TRACE_DEVICE_ATTR(act_mask); -static BLK_TRACE_DEVICE_ATTR(pid); -static BLK_TRACE_DEVICE_ATTR(start_lba); -static BLK_TRACE_DEVICE_ATTR(end_lba); - -static struct attribute *blk_trace_attrs[] = { - &dev_attr_enable.attr, - &dev_attr_act_mask.attr, - &dev_attr_pid.attr, - &dev_attr_start_lba.attr, - &dev_attr_end_lba.attr, - NULL -}; - -struct attribute_group blk_trace_attr_group = { - .name = "trace", - .attrs = blk_trace_attrs, -}; - -static int blk_str2act_mask(const char *str) -{ - int mask = 0; - char *copy = kstrdup(str, GFP_KERNEL), *s; - - if (copy == NULL) - return -ENOMEM; - - s = strstrip(copy); - - while (1) { - char *sep = strchr(s, ','); - - if (sep != NULL) - *sep = '\0'; - - if (strcasecmp(s, "barrier") == 0) - mask |= BLK_TC_BARRIER; - else if (strcasecmp(s, "complete") == 0) - mask |= BLK_TC_COMPLETE; - else if (strcasecmp(s, "fs") == 0) - mask |= BLK_TC_FS; - else if (strcasecmp(s, "issue") == 0) - mask |= BLK_TC_ISSUE; - else if (strcasecmp(s, "pc") == 0) - mask |= BLK_TC_PC; - else if (strcasecmp(s, "queue") == 0) - mask |= BLK_TC_QUEUE; - else if (strcasecmp(s, "read") == 0) - mask |= BLK_TC_READ; - else if (strcasecmp(s, "requeue") == 0) - mask |= BLK_TC_REQUEUE; - else if (strcasecmp(s, "sync") == 0) - mask |= BLK_TC_SYNC; - else if (strcasecmp(s, "write") == 0) - mask |= BLK_TC_WRITE; - - if (sep == NULL) - break; - - s = sep + 1; - } - kfree(copy); - - return mask; -} - -static ssize_t sysfs_blk_trace_attr_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct hd_struct *p = dev_to_part(dev); - struct request_queue *q; - struct block_device *bdev; - ssize_t ret = -ENXIO; - - lock_kernel(); - bdev = bdget(part_devt(p)); - if (bdev == NULL) - goto out_unlock_kernel; - - q = bdev_get_queue(bdev); - if (q == NULL) - goto out_bdput; - mutex_lock(&bdev->bd_mutex); - if (q->blk_trace == NULL) - ret = sprintf(buf, "disabled\n"); - else if (attr == &dev_attr_act_mask) - ret = sprintf(buf, "%#x\n", q->blk_trace->act_mask); - else if (attr == &dev_attr_pid) - ret = sprintf(buf, "%u\n", q->blk_trace->pid); - else if (attr == &dev_attr_start_lba) - ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); - else if (attr == &dev_attr_end_lba) - ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); - mutex_unlock(&bdev->bd_mutex); -out_bdput: - bdput(bdev); -out_unlock_kernel: - unlock_kernel(); - return ret; -} - -static ssize_t sysfs_blk_trace_attr_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct block_device *bdev; - struct request_queue *q; - struct hd_struct *p; - u64 value; - ssize_t ret = -ENXIO; - - if (count == 0) - goto out; - - if (attr == &dev_attr_act_mask) { - if (sscanf(buf, "%llx", &value) != 1) { - /* Assume it is a list of trace category names */ - value = blk_str2act_mask(buf); - if (value < 0) - goto out; - } - } else if (sscanf(buf, "%llu", &value) != 1) - goto out; - - lock_kernel(); - p = dev_to_part(dev); - bdev = bdget(part_devt(p)); - if (bdev == NULL) - goto out_unlock_kernel; - - q = bdev_get_queue(bdev); - if (q == NULL) - goto out_bdput; - - mutex_lock(&bdev->bd_mutex); - ret = 0; - if (q->blk_trace == NULL) - ret = blk_trace_setup_queue(q, bdev->bd_dev); - - if (ret == 0) { - if (attr == &dev_attr_act_mask) - q->blk_trace->act_mask = value; - else if (attr == &dev_attr_pid) - q->blk_trace->pid = value; - else if (attr == &dev_attr_start_lba) - q->blk_trace->start_lba = value; - else if (attr == &dev_attr_end_lba) - q->blk_trace->end_lba = value; - ret = count; - } - mutex_unlock(&bdev->bd_mutex); -out_bdput: - bdput(bdev); -out_unlock_kernel: - unlock_kernel(); -out: - return ret; -} |