| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Arnaldo Carvalho de Melo | 2788 | 31.10% | 9 | 3.53% |
| Jens Axboe | 1713 | 19.11% | 21 | 8.24% |
| Li Zefan | 1069 | 11.93% | 25 | 9.80% |
| Shaohua Li | 585 | 6.53% | 6 | 2.35% |
| Steven Rostedt | 383 | 4.27% | 18 | 7.06% |
| Jan Kara | 382 | 4.26% | 5 | 1.96% |
| Arnd Bergmann | 274 | 3.06% | 6 | 2.35% |
| Christoph Hellwig | 208 | 2.32% | 25 | 9.80% |
| Alan D. Brunelle | 179 | 2.00% | 5 | 1.96% |
| Ye Bin | 138 | 1.54% | 1 | 0.39% |
| Olaf Kirch | 122 | 1.36% | 1 | 0.39% |
| Jun'ichi Nomura | 104 | 1.16% | 1 | 0.39% |
| Luis R. Rodriguez | 94 | 1.05% | 5 | 1.96% |
| Christof Schmitt | 67 | 0.75% | 1 | 0.39% |
| Michael Christie | 65 | 0.73% | 3 | 1.18% |
| Namhyung Kim | 63 | 0.70% | 1 | 0.39% |
| Linus Torvalds (pre-git) | 53 | 0.59% | 16 | 6.27% |
| Linus Torvalds | 50 | 0.56% | 9 | 3.53% |
| yu kuai | 49 | 0.55% | 1 | 0.39% |
| Tejun Heo | 48 | 0.54% | 7 | 2.75% |
| Shawn Du | 34 | 0.38% | 1 | 0.39% |
| Kay Sievers | 34 | 0.38% | 2 | 0.78% |
| Bart Van Assche | 32 | 0.36% | 4 | 1.57% |
| Patrick Mochel | 32 | 0.36% | 2 | 0.78% |
| Al Viro | 29 | 0.32% | 9 | 3.53% |
| Andrew Morton | 27 | 0.30% | 8 | 3.14% |
| Chaitanya Kulkarni | 27 | 0.30% | 3 | 1.18% |
| Roman Peniaev | 26 | 0.29% | 1 | 0.39% |
| Sebastian Andrzej Siewior | 22 | 0.25% | 1 | 0.39% |
| David Woodhouse | 21 | 0.23% | 2 | 0.78% |
| Omar Sandoval | 20 | 0.22% | 3 | 1.18% |
| Kent Overstreet | 17 | 0.19% | 2 | 0.78% |
| Tao Ma | 16 | 0.18% | 2 | 0.78% |
| Niklas Svensson (Niklas Cassel) | 15 | 0.17% | 1 | 0.39% |
| Frédéric Weisbecker | 11 | 0.12% | 3 | 1.18% |
| Yang Jihong | 10 | 0.11% | 1 | 0.39% |
| Martin Schwidefsky | 10 | 0.11% | 2 | 0.78% |
| Stefan Raspl | 9 | 0.10% | 2 | 0.78% |
| Carl Henrik Lunde | 9 | 0.10% | 1 | 0.39% |
| Ingo Molnar | 8 | 0.09% | 2 | 0.78% |
| Zhihao Cheng | 8 | 0.09% | 1 | 0.39% |
| Alexey Dobriyan | 7 | 0.08% | 2 | 0.78% |
| Greg Kroah-Hartman | 7 | 0.08% | 2 | 0.78% |
| Waiman Long | 7 | 0.08% | 1 | 0.39% |
| Marcos Paulo de Souza | 6 | 0.07% | 1 | 0.39% |
| Dmitriy Monakhov | 6 | 0.07% | 1 | 0.39% |
| Chen Gang S | 6 | 0.07% | 1 | 0.39% |
| Rusty Russell | 5 | 0.06% | 1 | 0.39% |
| Dave Jones | 5 | 0.06% | 1 | 0.39% |
| Cengiz C | 5 | 0.06% | 1 | 0.39% |
| Nathan Scott | 5 | 0.06% | 1 | 0.39% |
| Mike Snitzer | 5 | 0.06% | 1 | 0.39% |
| Rasmus Villemoes | 4 | 0.04% | 1 | 0.39% |
| Janak Desai | 4 | 0.04% | 1 | 0.39% |
| Adrian Hunter | 4 | 0.04% | 1 | 0.39% |
| Wander Lairson Costa | 3 | 0.03% | 1 | 0.39% |
| Neil Brown | 3 | 0.03% | 1 | 0.39% |
| Paul Gortmaker | 3 | 0.03% | 1 | 0.39% |
| Mathieu Desnoyers | 2 | 0.02% | 1 | 0.39% |
| Qiujun Huang | 2 | 0.02% | 1 | 0.39% |
| Davidlohr Bueso A | 2 | 0.02% | 1 | 0.39% |
| Randy Dunlap | 2 | 0.02% | 1 | 0.39% |
| John Levon | 2 | 0.02% | 1 | 0.39% |
| Stephen Boyd | 2 | 0.02% | 1 | 0.39% |
| Joe Perches | 2 | 0.02% | 1 | 0.39% |
| Gustavo A. R. Silva | 2 | 0.02% | 1 | 0.39% |
| Matthew Dobson | 2 | 0.02% | 1 | 0.39% |
| Thomas Gleixner | 2 | 0.02% | 1 | 0.39% |
| Martin K. Petersen | 2 | 0.02% | 1 | 0.39% |
| Pavel Machek | 1 | 0.01% | 1 | 0.39% |
| Wang Hai | 1 | 0.01% | 1 | 0.39% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.39% |
| Yoann Padioleau | 1 | 0.01% | 1 | 0.39% |
| Jani Nikula | 1 | 0.01% | 1 | 0.39% |
| Shan Wei | 1 | 0.01% | 1 | 0.39% |
| Total | 8964 | 255 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> * */ #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; strscpy_pad(buts->name, name, BLKTRACE_BDEV_SIZE); /* * 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 = bdev_get_queue(bdev); int ret, start = 0; char b[BDEVNAME_SIZE]; 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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