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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) 2006 Jens Axboe <[email protected]>
- *
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #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/slab.h>
- #include <linux/debugfs.h>
- #include <linux/export.h>
- #include <linux/time.h>
- #include <linux/uaccess.h>
- #include <linux/list.h>
- #include <linux/blk-cgroup.h>
- #include "../../block/blk.h"
- #include <trace/events/block.h>
- #include "trace_output.h"
- #ifdef CONFIG_BLK_DEV_IO_TRACE
- static unsigned int blktrace_seq __read_mostly = 1;
- static struct trace_array *blk_tr;
- static bool blk_tracer_enabled __read_mostly;
- static LIST_HEAD(running_trace_list);
- static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(running_trace_lock);
- /* Select an alternative, minimalistic output than the original one */
- #define TRACE_BLK_OPT_CLASSIC 0x1
- #define TRACE_BLK_OPT_CGROUP 0x2
- #define TRACE_BLK_OPT_CGNAME 0x4
- static struct tracer_opt blk_tracer_opts[] = {
- /* Default disable the minimalistic output */
- { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
- #ifdef CONFIG_BLK_CGROUP
- { TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) },
- { TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) },
- #endif
- { }
- };
- 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 int blk_probes_ref;
- static void 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, u64 cgid)
- {
- struct blk_io_trace *t;
- struct ring_buffer_event *event = NULL;
- struct trace_buffer *buffer = NULL;
- unsigned int trace_ctx = 0;
- int cpu = smp_processor_id();
- bool blk_tracer = blk_tracer_enabled;
- ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
- if (blk_tracer) {
- buffer = blk_tr->array_buffer.buffer;
- trace_ctx = tracing_gen_ctx_flags(0);
- event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
- sizeof(*t) + len + cgid_len,
- trace_ctx);
- if (!event)
- return;
- t = ring_buffer_event_data(event);
- goto record_it;
- }
- if (!bt->rchan)
- return;
- t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len);
- if (t) {
- t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
- t->time = ktime_to_ns(ktime_get());
- record_it:
- t->device = bt->dev;
- t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
- t->pid = pid;
- t->cpu = cpu;
- t->pdu_len = len + cgid_len;
- if (cgid_len)
- memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
- memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
- if (blk_tracer)
- trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
- }
- }
- /*
- * Send out a notify for this process, if we haven't done so since a trace
- * started
- */
- static void trace_note_tsk(struct task_struct *tsk)
- {
- unsigned long flags;
- struct blk_trace *bt;
- tsk->btrace_seq = blktrace_seq;
- raw_spin_lock_irqsave(&running_trace_lock, flags);
- list_for_each_entry(bt, &running_trace_list, running_list) {
- trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
- sizeof(tsk->comm), 0);
- }
- raw_spin_unlock_irqrestore(&running_trace_lock, flags);
- }
- static void trace_note_time(struct blk_trace *bt)
- {
- struct timespec64 now;
- unsigned long flags;
- u32 words[2];
- /* need to check user space to see if this breaks in y2038 or y2106 */
- ktime_get_real_ts64(&now);
- words[0] = (u32)now.tv_sec;
- words[1] = now.tv_nsec;
- local_irq_save(flags);
- trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0);
- local_irq_restore(flags);
- }
- void __blk_trace_note_message(struct blk_trace *bt,
- struct cgroup_subsys_state *css, const char *fmt, ...)
- {
- int n;
- va_list args;
- unsigned long flags;
- char *buf;
- u64 cgid = 0;
- if (unlikely(bt->trace_state != Blktrace_running &&
- !blk_tracer_enabled))
- return;
- /*
- * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
- * message to the trace.
- */
- if (!(bt->act_mask & BLK_TC_NOTIFY))
- return;
- local_irq_save(flags);
- buf = this_cpu_ptr(bt->msg_data);
- va_start(args, fmt);
- n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
- va_end(args);
- #ifdef CONFIG_BLK_CGROUP
- if (css && (blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
- cgid = cgroup_id(css->cgroup);
- else
- cgid = 1;
- #endif
- trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, cgid);
- local_irq_restore(flags);
- }
- EXPORT_SYMBOL_GPL(__blk_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 && (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 const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
- BLK_TC_ACT(BLK_TC_WRITE) };
- #define BLK_TC_RAHEAD BLK_TC_AHEAD
- #define BLK_TC_PREFLUSH BLK_TC_FLUSH
- /* The ilog2() calls fall out because they're constant */
- #define MASK_TC_BIT(rw, __name) ((__force u32)(rw & REQ_ ## __name) << \
- (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __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,
- const blk_opf_t opf, u32 what, int error,
- int pdu_len, void *pdu_data, u64 cgid)
- {
- struct task_struct *tsk = current;
- struct ring_buffer_event *event = NULL;
- struct trace_buffer *buffer = NULL;
- struct blk_io_trace *t;
- unsigned long flags = 0;
- unsigned long *sequence;
- unsigned int trace_ctx = 0;
- pid_t pid;
- int cpu;
- bool blk_tracer = blk_tracer_enabled;
- ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
- const enum req_op op = opf & REQ_OP_MASK;
- if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
- return;
- what |= ddir_act[op_is_write(op) ? WRITE : READ];
- what |= MASK_TC_BIT(opf, SYNC);
- what |= MASK_TC_BIT(opf, RAHEAD);
- what |= MASK_TC_BIT(opf, META);
- what |= MASK_TC_BIT(opf, PREFLUSH);
- what |= MASK_TC_BIT(opf, FUA);
- if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)
- what |= BLK_TC_ACT(BLK_TC_DISCARD);
- if (op == REQ_OP_FLUSH)
- what |= BLK_TC_ACT(BLK_TC_FLUSH);
- if (cgid)
- what |= __BLK_TA_CGROUP;
- pid = tsk->pid;
- if (act_log_check(bt, what, sector, pid))
- return;
- cpu = raw_smp_processor_id();
- if (blk_tracer) {
- tracing_record_cmdline(current);
- buffer = blk_tr->array_buffer.buffer;
- trace_ctx = tracing_gen_ctx_flags(0);
- event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
- sizeof(*t) + pdu_len + cgid_len,
- trace_ctx);
- if (!event)
- return;
- t = ring_buffer_event_data(event);
- goto record_it;
- }
- if (unlikely(tsk->btrace_seq != blktrace_seq))
- trace_note_tsk(tsk);
- /*
- * 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);
- t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_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 + cgid_len;
- if (cgid_len)
- memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
- if (pdu_len)
- memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
- if (blk_tracer) {
- trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
- return;
- }
- }
- local_irq_restore(flags);
- }
- static void blk_trace_free(struct request_queue *q, struct blk_trace *bt)
- {
- relay_close(bt->rchan);
- /*
- * If 'bt->dir' is not set, then both 'dropped' and 'msg' are created
- * under 'q->debugfs_dir', thus lookup and remove them.
- */
- if (!bt->dir) {
- debugfs_lookup_and_remove("dropped", q->debugfs_dir);
- debugfs_lookup_and_remove("msg", q->debugfs_dir);
- } else {
- debugfs_remove(bt->dir);
- }
- free_percpu(bt->sequence);
- free_percpu(bt->msg_data);
- kfree(bt);
- }
- static void get_probe_ref(void)
- {
- mutex_lock(&blk_probe_mutex);
- if (++blk_probes_ref == 1)
- blk_register_tracepoints();
- mutex_unlock(&blk_probe_mutex);
- }
- static void put_probe_ref(void)
- {
- mutex_lock(&blk_probe_mutex);
- if (!--blk_probes_ref)
- blk_unregister_tracepoints();
- mutex_unlock(&blk_probe_mutex);
- }
- static int blk_trace_start(struct blk_trace *bt)
- {
- if (bt->trace_state != Blktrace_setup &&
- bt->trace_state != Blktrace_stopped)
- return -EINVAL;
- blktrace_seq++;
- smp_mb();
- bt->trace_state = Blktrace_running;
- raw_spin_lock_irq(&running_trace_lock);
- list_add(&bt->running_list, &running_trace_list);
- raw_spin_unlock_irq(&running_trace_lock);
- trace_note_time(bt);
- return 0;
- }
- static int blk_trace_stop(struct blk_trace *bt)
- {
- if (bt->trace_state != Blktrace_running)
- return -EINVAL;
- bt->trace_state = Blktrace_stopped;
- raw_spin_lock_irq(&running_trace_lock);
- list_del_init(&bt->running_list);
- raw_spin_unlock_irq(&running_trace_lock);
- relay_flush(bt->rchan);
- return 0;
- }
- static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt)
- {
- blk_trace_stop(bt);
- synchronize_rcu();
- blk_trace_free(q, bt);
- put_probe_ref();
- }
- static int __blk_trace_remove(struct request_queue *q)
- {
- struct blk_trace *bt;
- bt = rcu_replace_pointer(q->blk_trace, NULL,
- lockdep_is_held(&q->debugfs_mutex));
- if (!bt)
- return -EINVAL;
- blk_trace_cleanup(q, bt);
- return 0;
- }
- int blk_trace_remove(struct request_queue *q)
- {
- int ret;
- mutex_lock(&q->debugfs_mutex);
- ret = __blk_trace_remove(q);
- mutex_unlock(&q->debugfs_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blk_trace_remove);
- 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 = simple_open,
- .read = blk_dropped_read,
- .llseek = default_llseek,
- };
- 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 = memdup_user_nul(buffer, count);
- if (IS_ERR(msg))
- return PTR_ERR(msg);
- bt = filp->private_data;
- __blk_trace_note_message(bt, NULL, "%s", msg);
- kfree(msg);
- return count;
- }
- static const struct file_operations blk_msg_fops = {
- .owner = THIS_MODULE,
- .open = simple_open,
- .write = blk_msg_write,
- .llseek = noop_llseek,
- };
- /*
- * 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)
- {
- debugfs_remove(dentry);
- return 0;
- }
- static struct dentry *blk_create_buf_file_callback(const char *filename,
- struct dentry *parent,
- umode_t mode,
- struct rchan_buf *buf,
- int *is_global)
- {
- return debugfs_create_file(filename, mode, parent, buf,
- &relay_file_operations);
- }
- static const 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,
- };
- static void blk_trace_setup_lba(struct blk_trace *bt,
- struct block_device *bdev)
- {
- if (bdev) {
- bt->start_lba = bdev->bd_start_sect;
- bt->end_lba = bdev->bd_start_sect + bdev_nr_sectors(bdev);
- } else {
- bt->start_lba = 0;
- bt->end_lba = -1ULL;
- }
- }
- /*
- * Setup everything required to start tracing
- */
- static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
- struct block_device *bdev,
- struct blk_user_trace_setup *buts)
- {
- struct blk_trace *bt = NULL;
- struct dentry *dir = NULL;
- int ret;
- lockdep_assert_held(&q->debugfs_mutex);
- 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
- */
- strreplace(buts->name, '/', '_');
- /*
- * bdev can be NULL, as with scsi-generic, this is a helpful as
- * we can be.
- */
- if (rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex))) {
- pr_warn("Concurrent blktraces are not allowed on %s\n",
- buts->name);
- return -EBUSY;
- }
- bt = kzalloc(sizeof(*bt), GFP_KERNEL);
- if (!bt)
- return -ENOMEM;
- ret = -ENOMEM;
- bt->sequence = alloc_percpu(unsigned long);
- if (!bt->sequence)
- goto err;
- bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
- if (!bt->msg_data)
- goto err;
- /*
- * When tracing the whole disk reuse the existing debugfs directory
- * created by the block layer on init. For partitions block devices,
- * and scsi-generic block devices we create a temporary new debugfs
- * directory that will be removed once the trace ends.
- */
- if (bdev && !bdev_is_partition(bdev))
- dir = q->debugfs_dir;
- else
- bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
- /*
- * As blktrace relies on debugfs for its interface the debugfs directory
- * is required, contrary to the usual mantra of not checking for debugfs
- * files or directories.
- */
- if (IS_ERR_OR_NULL(dir)) {
- pr_warn("debugfs_dir not present for %s so skipping\n",
- buts->name);
- ret = -ENOENT;
- goto err;
- }
- bt->dev = dev;
- atomic_set(&bt->dropped, 0);
- INIT_LIST_HEAD(&bt->running_list);
- ret = -EIO;
- debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
- debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
- 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;
- blk_trace_setup_lba(bt, bdev);
- /* overwrite with user settings */
- if (buts->start_lba)
- bt->start_lba = buts->start_lba;
- if (buts->end_lba)
- bt->end_lba = buts->end_lba;
- bt->pid = buts->pid;
- bt->trace_state = Blktrace_setup;
- rcu_assign_pointer(q->blk_trace, bt);
- get_probe_ref();
- ret = 0;
- err:
- if (ret)
- blk_trace_free(q, bt);
- return ret;
- }
- static int __blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
- struct block_device *bdev, 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, bdev, &buts);
- if (ret)
- return ret;
- if (copy_to_user(arg, &buts, sizeof(buts))) {
- __blk_trace_remove(q);
- return -EFAULT;
- }
- return 0;
- }
- int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
- struct block_device *bdev,
- char __user *arg)
- {
- int ret;
- mutex_lock(&q->debugfs_mutex);
- ret = __blk_trace_setup(q, name, dev, bdev, arg);
- mutex_unlock(&q->debugfs_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blk_trace_setup);
- #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
- static int compat_blk_trace_setup(struct request_queue *q, char *name,
- dev_t dev, struct block_device *bdev,
- char __user *arg)
- {
- struct blk_user_trace_setup buts;
- struct compat_blk_user_trace_setup cbuts;
- int ret;
- if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
- return -EFAULT;
- buts = (struct blk_user_trace_setup) {
- .act_mask = cbuts.act_mask,
- .buf_size = cbuts.buf_size,
- .buf_nr = cbuts.buf_nr,
- .start_lba = cbuts.start_lba,
- .end_lba = cbuts.end_lba,
- .pid = cbuts.pid,
- };
- ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
- if (ret)
- return ret;
- if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
- __blk_trace_remove(q);
- return -EFAULT;
- }
- return 0;
- }
- #endif
- static int __blk_trace_startstop(struct request_queue *q, int start)
- {
- struct blk_trace *bt;
- bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex));
- if (bt == NULL)
- return -EINVAL;
- if (start)
- return blk_trace_start(bt);
- else
- return blk_trace_stop(bt);
- }
- int blk_trace_startstop(struct request_queue *q, int start)
- {
- int ret;
- mutex_lock(&q->debugfs_mutex);
- ret = __blk_trace_startstop(q, start);
- mutex_unlock(&q->debugfs_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blk_trace_startstop);
- /*
- * When reading or writing the blktrace sysfs files, the references to the
- * opened sysfs or device files should prevent the underlying block device
- * from being removed. So no further delete protection is really needed.
- */
- /**
- * 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(&q->debugfs_mutex);
- switch (cmd) {
- case BLKTRACESETUP:
- snprintf(b, sizeof(b), "%pg", bdev);
- ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
- break;
- #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
- case BLKTRACESETUP32:
- snprintf(b, sizeof(b), "%pg", bdev);
- ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
- break;
- #endif
- case BLKTRACESTART:
- start = 1;
- fallthrough;
- case BLKTRACESTOP:
- ret = __blk_trace_startstop(q, start);
- break;
- case BLKTRACETEARDOWN:
- ret = __blk_trace_remove(q);
- break;
- default:
- ret = -ENOTTY;
- break;
- }
- mutex_unlock(&q->debugfs_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 (rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex)))
- __blk_trace_remove(q);
- }
- #ifdef CONFIG_BLK_CGROUP
- static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
- {
- struct cgroup_subsys_state *blkcg_css;
- struct blk_trace *bt;
- /* We don't use the 'bt' value here except as an optimization... */
- bt = rcu_dereference_protected(q->blk_trace, 1);
- if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
- return 0;
- blkcg_css = bio_blkcg_css(bio);
- if (!blkcg_css)
- return 0;
- return cgroup_id(blkcg_css->cgroup);
- }
- #else
- static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
- {
- return 0;
- }
- #endif
- static u64
- blk_trace_request_get_cgid(struct request *rq)
- {
- if (!rq->bio)
- return 0;
- /* Use the first bio */
- return blk_trace_bio_get_cgid(rq->q, rq->bio);
- }
- /*
- * blktrace probes
- */
- /**
- * blk_add_trace_rq - Add a trace for a request oriented action
- * @rq: the source request
- * @error: return status to log
- * @nr_bytes: number of completed bytes
- * @what: the action
- * @cgid: the cgroup info
- *
- * Description:
- * Records an action against a request. Will log the bio offset + size.
- *
- **/
- static void blk_add_trace_rq(struct request *rq, blk_status_t error,
- unsigned int nr_bytes, u32 what, u64 cgid)
- {
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(rq->q->blk_trace);
- if (likely(!bt)) {
- rcu_read_unlock();
- return;
- }
- if (blk_rq_is_passthrough(rq))
- what |= BLK_TC_ACT(BLK_TC_PC);
- else
- what |= BLK_TC_ACT(BLK_TC_FS);
- __blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, rq->cmd_flags,
- what, blk_status_to_errno(error), 0, NULL, cgid);
- rcu_read_unlock();
- }
- static void blk_add_trace_rq_insert(void *ignore, struct request *rq)
- {
- blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
- blk_trace_request_get_cgid(rq));
- }
- static void blk_add_trace_rq_issue(void *ignore, struct request *rq)
- {
- blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
- blk_trace_request_get_cgid(rq));
- }
- static void blk_add_trace_rq_merge(void *ignore, struct request *rq)
- {
- blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
- blk_trace_request_get_cgid(rq));
- }
- static void blk_add_trace_rq_requeue(void *ignore, struct request *rq)
- {
- blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
- blk_trace_request_get_cgid(rq));
- }
- static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
- blk_status_t error, unsigned int nr_bytes)
- {
- blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
- blk_trace_request_get_cgid(rq));
- }
- /**
- * 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
- * @error: error, if any
- *
- * 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, int error)
- {
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(q->blk_trace);
- if (likely(!bt)) {
- rcu_read_unlock();
- return;
- }
- __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
- bio->bi_opf, what, error, 0, NULL,
- blk_trace_bio_get_cgid(q, bio));
- rcu_read_unlock();
- }
- static void blk_add_trace_bio_bounce(void *ignore, struct bio *bio)
- {
- blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_BOUNCE, 0);
- }
- static void blk_add_trace_bio_complete(void *ignore,
- struct request_queue *q, struct bio *bio)
- {
- blk_add_trace_bio(q, bio, BLK_TA_COMPLETE,
- blk_status_to_errno(bio->bi_status));
- }
- static void blk_add_trace_bio_backmerge(void *ignore, struct bio *bio)
- {
- blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_BACKMERGE,
- 0);
- }
- static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio)
- {
- blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_FRONTMERGE,
- 0);
- }
- static void blk_add_trace_bio_queue(void *ignore, struct bio *bio)
- {
- blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_QUEUE, 0);
- }
- static void blk_add_trace_getrq(void *ignore, struct bio *bio)
- {
- blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_GETRQ, 0);
- }
- static void blk_add_trace_plug(void *ignore, struct request_queue *q)
- {
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(q->blk_trace);
- if (bt)
- __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0);
- rcu_read_unlock();
- }
- static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
- unsigned int depth, bool explicit)
- {
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(q->blk_trace);
- if (bt) {
- __be64 rpdu = cpu_to_be64(depth);
- u32 what;
- if (explicit)
- what = BLK_TA_UNPLUG_IO;
- else
- what = BLK_TA_UNPLUG_TIMER;
- __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0);
- }
- rcu_read_unlock();
- }
- static void blk_add_trace_split(void *ignore, struct bio *bio, unsigned int pdu)
- {
- struct request_queue *q = bio->bi_bdev->bd_disk->queue;
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(q->blk_trace);
- if (bt) {
- __be64 rpdu = cpu_to_be64(pdu);
- __blk_add_trace(bt, bio->bi_iter.bi_sector,
- bio->bi_iter.bi_size, bio->bi_opf, BLK_TA_SPLIT,
- blk_status_to_errno(bio->bi_status),
- sizeof(rpdu), &rpdu,
- blk_trace_bio_get_cgid(q, bio));
- }
- rcu_read_unlock();
- }
- /**
- * blk_add_trace_bio_remap - Add a trace for a bio-remap operation
- * @ignore: trace callback data parameter (not used)
- * @bio: the source bio
- * @dev: source device
- * @from: source sector
- *
- * Called after a bio is remapped to a different device and/or sector.
- **/
- static void blk_add_trace_bio_remap(void *ignore, struct bio *bio, dev_t dev,
- sector_t from)
- {
- struct request_queue *q = bio->bi_bdev->bd_disk->queue;
- struct blk_trace *bt;
- struct blk_io_trace_remap r;
- rcu_read_lock();
- bt = rcu_dereference(q->blk_trace);
- if (likely(!bt)) {
- rcu_read_unlock();
- return;
- }
- r.device_from = cpu_to_be32(dev);
- r.device_to = cpu_to_be32(bio_dev(bio));
- r.sector_from = cpu_to_be64(from);
- __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
- bio->bi_opf, BLK_TA_REMAP,
- blk_status_to_errno(bio->bi_status),
- sizeof(r), &r, blk_trace_bio_get_cgid(q, bio));
- rcu_read_unlock();
- }
- /**
- * blk_add_trace_rq_remap - Add a trace for a request-remap operation
- * @ignore: trace callback data parameter (not used)
- * @rq: the source request
- * @dev: target device
- * @from: source sector
- *
- * Description:
- * Device mapper remaps request to other devices.
- * Add a trace for that action.
- *
- **/
- static void blk_add_trace_rq_remap(void *ignore, struct request *rq, dev_t dev,
- sector_t from)
- {
- struct blk_trace *bt;
- struct blk_io_trace_remap r;
- rcu_read_lock();
- bt = rcu_dereference(rq->q->blk_trace);
- if (likely(!bt)) {
- rcu_read_unlock();
- return;
- }
- r.device_from = cpu_to_be32(dev);
- r.device_to = cpu_to_be32(disk_devt(rq->q->disk));
- r.sector_from = cpu_to_be64(from);
- __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
- rq->cmd_flags, BLK_TA_REMAP, 0,
- sizeof(r), &r, blk_trace_request_get_cgid(rq));
- rcu_read_unlock();
- }
- /**
- * blk_add_driver_data - Add binary message with driver-specific data
- * @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 *rq, void *data, size_t len)
- {
- struct blk_trace *bt;
- rcu_read_lock();
- bt = rcu_dereference(rq->q->blk_trace);
- if (likely(!bt)) {
- rcu_read_unlock();
- return;
- }
- __blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0,
- BLK_TA_DRV_DATA, 0, len, data,
- blk_trace_request_get_cgid(rq));
- rcu_read_unlock();
- }
- EXPORT_SYMBOL_GPL(blk_add_driver_data);
- static void blk_register_tracepoints(void)
- {
- int ret;
- ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
- WARN_ON(ret);
- ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
- WARN_ON(ret);
- ret = register_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
- WARN_ON(ret);
- ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
- WARN_ON(ret);
- ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
- WARN_ON(ret);
- ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
- WARN_ON(ret);
- ret = register_trace_block_plug(blk_add_trace_plug, NULL);
- WARN_ON(ret);
- ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
- WARN_ON(ret);
- ret = register_trace_block_split(blk_add_trace_split, NULL);
- WARN_ON(ret);
- ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
- WARN_ON(ret);
- ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
- WARN_ON(ret);
- }
- static void blk_unregister_tracepoints(void)
- {
- unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
- unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
- unregister_trace_block_split(blk_add_trace_split, NULL);
- unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
- unregister_trace_block_plug(blk_add_trace_plug, NULL);
- unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
- unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
- unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
- unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
- unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
- unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
- unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
- unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
- unregister_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
- unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
- unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
- tracepoint_synchronize_unregister();
- }
- /*
- * struct blk_io_tracer formatting routines
- */
- static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
- {
- int i = 0;
- int tc = t->action >> BLK_TC_SHIFT;
- if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
- rwbs[i++] = 'N';
- goto out;
- }
- if (tc & BLK_TC_FLUSH)
- rwbs[i++] = 'F';
- if (tc & BLK_TC_DISCARD)
- rwbs[i++] = 'D';
- else if (tc & BLK_TC_WRITE)
- rwbs[i++] = 'W';
- else if (t->bytes)
- rwbs[i++] = 'R';
- else
- rwbs[i++] = 'N';
- if (tc & BLK_TC_FUA)
- rwbs[i++] = 'F';
- if (tc & BLK_TC_AHEAD)
- rwbs[i++] = 'A';
- if (tc & BLK_TC_SYNC)
- rwbs[i++] = 'S';
- if (tc & BLK_TC_META)
- rwbs[i++] = 'M';
- out:
- 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, bool has_cg)
- {
- return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0);
- }
- static inline u64 t_cgid(const struct trace_entry *ent)
- {
- return *(u64 *)(te_blk_io_trace(ent) + 1);
- }
- static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
- {
- return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0);
- }
- static inline u32 t_action(const struct trace_entry *ent)
- {
- return te_blk_io_trace(ent)->action;
- }
- static inline u32 t_bytes(const struct trace_entry *ent)
- {
- return te_blk_io_trace(ent)->bytes;
- }
- 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)->error;
- }
- static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg)
- {
- const __be64 *val = pdu_start(ent, has_cg);
- return be64_to_cpu(*val);
- }
- typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act,
- bool has_cg);
- static void blk_log_action_classic(struct trace_iterator *iter, const char *act,
- bool has_cg)
- {
- char rwbs[RWBS_LEN];
- unsigned long long ts = iter->ts;
- unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
- unsigned secs = (unsigned long)ts;
- const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
- fill_rwbs(rwbs, t);
- trace_seq_printf(&iter->seq,
- "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
- MAJOR(t->device), MINOR(t->device), iter->cpu,
- secs, nsec_rem, iter->ent->pid, act, rwbs);
- }
- static void blk_log_action(struct trace_iterator *iter, const char *act,
- bool has_cg)
- {
- char rwbs[RWBS_LEN];
- const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
- fill_rwbs(rwbs, t);
- if (has_cg) {
- u64 id = t_cgid(iter->ent);
- if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
- char blkcg_name_buf[NAME_MAX + 1] = "<...>";
- cgroup_path_from_kernfs_id(id, blkcg_name_buf,
- sizeof(blkcg_name_buf));
- trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
- MAJOR(t->device), MINOR(t->device),
- blkcg_name_buf, act, rwbs);
- } else {
- /*
- * The cgid portion used to be "INO,GEN". Userland
- * builds a FILEID_INO32_GEN fid out of them and
- * opens the cgroup using open_by_handle_at(2).
- * While 32bit ino setups are still the same, 64bit
- * ones now use the 64bit ino as the whole ID and
- * no longer use generation.
- *
- * Regardless of the content, always output
- * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can
- * be mapped back to @id on both 64 and 32bit ino
- * setups. See __kernfs_fh_to_dentry().
- */
- trace_seq_printf(&iter->seq,
- "%3d,%-3d %llx,%-llx %2s %3s ",
- MAJOR(t->device), MINOR(t->device),
- id & U32_MAX, id >> 32, act, rwbs);
- }
- } else
- trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
- MAJOR(t->device), MINOR(t->device), act, rwbs);
- }
- static void blk_log_dump_pdu(struct trace_seq *s,
- const struct trace_entry *ent, bool has_cg)
- {
- const unsigned char *pdu_buf;
- int pdu_len;
- int i, end;
- pdu_buf = pdu_start(ent, has_cg);
- pdu_len = pdu_real_len(ent, has_cg);
- if (!pdu_len)
- return;
- /* find the last zero that needs to be printed */
- for (end = pdu_len - 1; end >= 0; end--)
- if (pdu_buf[end])
- break;
- end++;
- trace_seq_putc(s, '(');
- for (i = 0; i < pdu_len; i++) {
- trace_seq_printf(s, "%s%02x",
- i == 0 ? "" : " ", pdu_buf[i]);
- /*
- * stop when the rest is just zeros and indicate so
- * with a ".." appended
- */
- if (i == end && end != pdu_len - 1) {
- trace_seq_puts(s, " ..) ");
- return;
- }
- }
- trace_seq_puts(s, ") ");
- }
- static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
- {
- char cmd[TASK_COMM_LEN];
- trace_find_cmdline(ent->pid, cmd);
- if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
- trace_seq_printf(s, "%u ", t_bytes(ent));
- blk_log_dump_pdu(s, ent, has_cg);
- trace_seq_printf(s, "[%s]\n", cmd);
- } else {
- if (t_sec(ent))
- trace_seq_printf(s, "%llu + %u [%s]\n",
- t_sector(ent), t_sec(ent), cmd);
- else
- trace_seq_printf(s, "[%s]\n", cmd);
- }
- }
- static void blk_log_with_error(struct trace_seq *s,
- const struct trace_entry *ent, bool has_cg)
- {
- if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
- blk_log_dump_pdu(s, ent, has_cg);
- trace_seq_printf(s, "[%d]\n", t_error(ent));
- } else {
- if (t_sec(ent))
- trace_seq_printf(s, "%llu + %u [%d]\n",
- t_sector(ent),
- t_sec(ent), t_error(ent));
- else
- trace_seq_printf(s, "%llu [%d]\n",
- t_sector(ent), t_error(ent));
- }
- }
- static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
- {
- const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg);
- trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
- t_sector(ent), t_sec(ent),
- MAJOR(be32_to_cpu(__r->device_from)),
- MINOR(be32_to_cpu(__r->device_from)),
- be64_to_cpu(__r->sector_from));
- }
- static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
- {
- char cmd[TASK_COMM_LEN];
- trace_find_cmdline(ent->pid, cmd);
- trace_seq_printf(s, "[%s]\n", cmd);
- }
- static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
- {
- char cmd[TASK_COMM_LEN];
- trace_find_cmdline(ent->pid, cmd);
- trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg));
- }
- static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
- {
- char cmd[TASK_COMM_LEN];
- trace_find_cmdline(ent->pid, cmd);
- trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
- get_pdu_int(ent, has_cg), cmd);
- }
- static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent,
- bool has_cg)
- {
- trace_seq_putmem(s, pdu_start(ent, has_cg),
- pdu_real_len(ent, has_cg));
- trace_seq_putc(s, '\n');
- }
- /*
- * 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)
- {
- blk_tracer_enabled = true;
- }
- static int blk_tracer_init(struct trace_array *tr)
- {
- blk_tr = tr;
- blk_tracer_start(tr);
- return 0;
- }
- static void blk_tracer_stop(struct trace_array *tr)
- {
- blk_tracer_enabled = false;
- }
- static void blk_tracer_reset(struct trace_array *tr)
- {
- blk_tracer_stop(tr);
- }
- static const struct {
- const char *act[2];
- void (*print)(struct trace_seq *s, const struct trace_entry *ent,
- bool has_cg);
- } what2act[] = {
- [__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 print_one_line(struct trace_iterator *iter,
- bool classic)
- {
- struct trace_array *tr = iter->tr;
- struct trace_seq *s = &iter->seq;
- const struct blk_io_trace *t;
- u16 what;
- bool long_act;
- blk_log_action_t *log_action;
- bool has_cg;
- t = te_blk_io_trace(iter->ent);
- what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP;
- long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE);
- log_action = classic ? &blk_log_action_classic : &blk_log_action;
- has_cg = t->action & __BLK_TA_CGROUP;
- if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
- log_action(iter, long_act ? "message" : "m", has_cg);
- blk_log_msg(s, iter->ent, has_cg);
- return trace_handle_return(s);
- }
- if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
- trace_seq_printf(s, "Unknown action %x\n", what);
- else {
- log_action(iter, what2act[what].act[long_act], has_cg);
- what2act[what].print(s, iter->ent, has_cg);
- }
- return trace_handle_return(s);
- }
- static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
- int flags, struct trace_event *event)
- {
- return print_one_line(iter, false);
- }
- static void 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 = iter->ts,
- };
- trace_seq_putmem(s, &old, offset);
- 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,
- struct trace_event *event)
- {
- blk_trace_synthesize_old_trace(iter);
- return trace_handle_return(&iter->seq);
- }
- static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
- {
- if ((iter->ent->type != TRACE_BLK) ||
- !(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
- return TRACE_TYPE_UNHANDLED;
- return print_one_line(iter, true);
- }
- static int
- blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
- {
- /* don't output context-info for blk_classic output */
- if (bit == TRACE_BLK_OPT_CLASSIC) {
- if (set)
- tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
- else
- tr->trace_flags |= TRACE_ITER_CONTEXT_INFO;
- }
- return 0;
- }
- 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,
- .set_flag = blk_tracer_set_flag,
- };
- static struct trace_event_functions trace_blk_event_funcs = {
- .trace = blk_trace_event_print,
- .binary = blk_trace_event_print_binary,
- };
- static struct trace_event trace_blk_event = {
- .type = TRACE_BLK,
- .funcs = &trace_blk_event_funcs,
- };
- static int __init init_blk_tracer(void)
- {
- if (!register_trace_event(&trace_blk_event)) {
- pr_warn("Warning: could not register block events\n");
- return 1;
- }
- if (register_tracer(&blk_tracer) != 0) {
- pr_warn("Warning: could not register the block tracer\n");
- unregister_trace_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 = rcu_replace_pointer(q->blk_trace, NULL,
- lockdep_is_held(&q->debugfs_mutex));
- if (bt == NULL)
- return -EINVAL;
- blk_trace_stop(bt);
- put_probe_ref();
- synchronize_rcu();
- blk_trace_free(q, bt);
- return 0;
- }
- /*
- * Setup everything required to start tracing
- */
- static int blk_trace_setup_queue(struct request_queue *q,
- struct block_device *bdev)
- {
- struct blk_trace *bt = NULL;
- int ret = -ENOMEM;
- bt = kzalloc(sizeof(*bt), GFP_KERNEL);
- if (!bt)
- return -ENOMEM;
- bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
- if (!bt->msg_data)
- goto free_bt;
- bt->dev = bdev->bd_dev;
- bt->act_mask = (u16)-1;
- blk_trace_setup_lba(bt, bdev);
- rcu_assign_pointer(q->blk_trace, bt);
- get_probe_ref();
- return 0;
- free_bt:
- blk_trace_free(q, bt);
- return ret;
- }
- /*
- * sysfs interface to enable and configure tracing
- */
- 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 BLK_TRACE_DEVICE_ATTR(enable);
- 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 const struct {
- int mask;
- const char *str;
- } mask_maps[] = {
- { BLK_TC_READ, "read" },
- { BLK_TC_WRITE, "write" },
- { BLK_TC_FLUSH, "flush" },
- { BLK_TC_SYNC, "sync" },
- { BLK_TC_QUEUE, "queue" },
- { BLK_TC_REQUEUE, "requeue" },
- { BLK_TC_ISSUE, "issue" },
- { BLK_TC_COMPLETE, "complete" },
- { BLK_TC_FS, "fs" },
- { BLK_TC_PC, "pc" },
- { BLK_TC_NOTIFY, "notify" },
- { BLK_TC_AHEAD, "ahead" },
- { BLK_TC_META, "meta" },
- { BLK_TC_DISCARD, "discard" },
- { BLK_TC_DRV_DATA, "drv_data" },
- { BLK_TC_FUA, "fua" },
- };
- static int blk_trace_str2mask(const char *str)
- {
- int i;
- int mask = 0;
- char *buf, *s, *token;
- buf = kstrdup(str, GFP_KERNEL);
- if (buf == NULL)
- return -ENOMEM;
- s = strstrip(buf);
- while (1) {
- token = strsep(&s, ",");
- if (token == NULL)
- break;
- if (*token == '\0')
- continue;
- for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
- if (strcasecmp(token, mask_maps[i].str) == 0) {
- mask |= mask_maps[i].mask;
- break;
- }
- }
- if (i == ARRAY_SIZE(mask_maps)) {
- mask = -EINVAL;
- break;
- }
- }
- kfree(buf);
- return mask;
- }
- static ssize_t blk_trace_mask2str(char *buf, int mask)
- {
- int i;
- char *p = buf;
- for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
- if (mask & mask_maps[i].mask) {
- p += sprintf(p, "%s%s",
- (p == buf) ? "" : ",", mask_maps[i].str);
- }
- }
- *p++ = '\n';
- return p - buf;
- }
- static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- struct block_device *bdev = dev_to_bdev(dev);
- struct request_queue *q = bdev_get_queue(bdev);
- struct blk_trace *bt;
- ssize_t ret = -ENXIO;
- mutex_lock(&q->debugfs_mutex);
- bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex));
- if (attr == &dev_attr_enable) {
- ret = sprintf(buf, "%u\n", !!bt);
- goto out_unlock_bdev;
- }
- if (bt == NULL)
- ret = sprintf(buf, "disabled\n");
- else if (attr == &dev_attr_act_mask)
- ret = blk_trace_mask2str(buf, bt->act_mask);
- else if (attr == &dev_attr_pid)
- ret = sprintf(buf, "%u\n", bt->pid);
- else if (attr == &dev_attr_start_lba)
- ret = sprintf(buf, "%llu\n", bt->start_lba);
- else if (attr == &dev_attr_end_lba)
- ret = sprintf(buf, "%llu\n", bt->end_lba);
- out_unlock_bdev:
- mutex_unlock(&q->debugfs_mutex);
- 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 = dev_to_bdev(dev);
- struct request_queue *q = bdev_get_queue(bdev);
- struct blk_trace *bt;
- u64 value;
- ssize_t ret = -EINVAL;
- if (count == 0)
- goto out;
- if (attr == &dev_attr_act_mask) {
- if (kstrtoull(buf, 0, &value)) {
- /* Assume it is a list of trace category names */
- ret = blk_trace_str2mask(buf);
- if (ret < 0)
- goto out;
- value = ret;
- }
- } else {
- if (kstrtoull(buf, 0, &value))
- goto out;
- }
- mutex_lock(&q->debugfs_mutex);
- bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex));
- if (attr == &dev_attr_enable) {
- if (!!value == !!bt) {
- ret = 0;
- goto out_unlock_bdev;
- }
- if (value)
- ret = blk_trace_setup_queue(q, bdev);
- else
- ret = blk_trace_remove_queue(q);
- goto out_unlock_bdev;
- }
- ret = 0;
- if (bt == NULL) {
- ret = blk_trace_setup_queue(q, bdev);
- bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->debugfs_mutex));
- }
- if (ret == 0) {
- if (attr == &dev_attr_act_mask)
- bt->act_mask = value;
- else if (attr == &dev_attr_pid)
- bt->pid = value;
- else if (attr == &dev_attr_start_lba)
- bt->start_lba = value;
- else if (attr == &dev_attr_end_lba)
- bt->end_lba = value;
- }
- out_unlock_bdev:
- mutex_unlock(&q->debugfs_mutex);
- out:
- return ret ? ret : count;
- }
- #endif /* CONFIG_BLK_DEV_IO_TRACE */
- #ifdef CONFIG_EVENT_TRACING
- /**
- * blk_fill_rwbs - Fill the buffer rwbs by mapping op to character string.
- * @rwbs: buffer to be filled
- * @opf: request operation type (REQ_OP_XXX) and flags for the tracepoint
- *
- * Description:
- * Maps each request operation and flag to a single character and fills the
- * buffer provided by the caller with resulting string.
- *
- **/
- void blk_fill_rwbs(char *rwbs, blk_opf_t opf)
- {
- int i = 0;
- if (opf & REQ_PREFLUSH)
- rwbs[i++] = 'F';
- switch (opf & REQ_OP_MASK) {
- case REQ_OP_WRITE:
- rwbs[i++] = 'W';
- break;
- case REQ_OP_DISCARD:
- rwbs[i++] = 'D';
- break;
- case REQ_OP_SECURE_ERASE:
- rwbs[i++] = 'D';
- rwbs[i++] = 'E';
- break;
- case REQ_OP_FLUSH:
- rwbs[i++] = 'F';
- break;
- case REQ_OP_READ:
- rwbs[i++] = 'R';
- break;
- default:
- rwbs[i++] = 'N';
- }
- if (opf & REQ_FUA)
- rwbs[i++] = 'F';
- if (opf & REQ_RAHEAD)
- rwbs[i++] = 'A';
- if (opf & REQ_SYNC)
- rwbs[i++] = 'S';
- if (opf & REQ_META)
- rwbs[i++] = 'M';
- rwbs[i] = '\0';
- }
- EXPORT_SYMBOL_GPL(blk_fill_rwbs);
- #endif /* CONFIG_EVENT_TRACING */
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