/* * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */#include <linux/kernel.h>#include <linux/blkdev.h>#include <linux/blktrace_api.h>#include <linux/percpu.h>#include <linux/init.h>#include <linux/mutex.h>#include <linux/slab.h>#include <linux/debugfs.h>#include <linux/smp_lock.h>#include <linux/time.h>#include <linux/uaccess.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; /* Select an alternative, minimalistic output than the original one */#define TRACE_BLK_OPT_CLASSIC 0x1 static struct tracer_opt blk_tracer_opts[] = { /* Default disable the minimalistic output */ { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, { }}; static struct tracer_flags blk_tracer_flags = { .val = 0, .opts = blk_tracer_opts,}; /* Global reference count of probes */static atomic_t blk_probes_ref = ATOMIC_INIT(0); 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){ struct blk_io_trace *t; struct ring_buffer_event *event = NULL; struct ring_buffer *buffer = NULL; int pc = 0; int cpu = smp_processor_id(); bool blk_tracer = blk_tracer_enabled; if (blk_tracer) { buffer = blk_tr->buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + len, 0, pc); if (!event) return; t = ring_buffer_event_data(event); goto record_it; } if (!bt->rchan) return; t = relay_reserve(bt->rchan, sizeof(*t) + 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; t->pid = pid; t->cpu = cpu; t->pdu_len = len; memcpy((void *) t + sizeof(*t), data, len); if (blk_tracer) trace_buffer_unlock_commit(buffer, event, 0, pc); }} /* * Send out a notify for this process, if we haven't done so since a trace * started */static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk){ tsk->btrace_seq = blktrace_seq; trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));} static void trace_note_time(struct blk_trace *bt){ struct timespec now; unsigned long flags; u32 words[2]; getnstimeofday(&now); words[0] = now.tv_sec; words[1] = now.tv_nsec; local_irq_save(flags); trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); local_irq_restore(flags);} void __trace_note_message(struct blk_trace *bt, const char *fmt, ...){ int n; va_list args; unsigned long flags; char *buf; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer_enabled)) return; local_irq_save(flags); buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); va_start(args, fmt); n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); va_end(args); trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); local_irq_restore(flags);}EXPORT_SYMBOL_GPL(__trace_note_message); static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, pid_t pid){ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) return 1; if (sector && (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_HARDBARRIER BLK_TC_BARRIER#define BLK_TC_RAHEAD BLK_TC_AHEAD /* The ilog2() calls fall out because they're constant */#define MASK_TC_BIT(rw, __name) ((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, int rw, u32 what, int error, int pdu_len, void *pdu_data){ struct task_struct *tsk = current; struct ring_buffer_event *event = NULL; struct ring_buffer *buffer = NULL; struct blk_io_trace *t; unsigned long flags = 0; unsigned long *sequence; pid_t pid; int cpu, pc = 0; bool blk_tracer = blk_tracer_enabled; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) return; what |= ddir_act[rw & WRITE]; what |= MASK_TC_BIT(rw, HARDBARRIER); what |= MASK_TC_BIT(rw, SYNC); what |= MASK_TC_BIT(rw, RAHEAD); what |= MASK_TC_BIT(rw, META); what |= MASK_TC_BIT(rw, DISCARD); 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->buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + pdu_len, 0, pc); if (!event) return; t = ring_buffer_event_data(event); goto record_it; } /* * A word about the locking here - we disable interrupts to reserve * some space in the relay per-cpu buffer, to prevent an irq * from coming in and stepping on our toes. */ local_irq_save(flags); if (unlikely(tsk->btrace_seq != blktrace_seq)) trace_note_tsk(bt, tsk); t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); if (t) { sequence = per_cpu_ptr(bt->sequence, cpu); t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; t->sequence = ++(*sequence); t->time = ktime_to_ns(ktime_get());record_it: /* * These two are not needed in ftrace as they are in the * generic trace_entry, filled by tracing_generic_entry_update, * but for the trace_event->bin() synthesizer benefit we do it * here too. */ t->cpu = cpu; t->pid = pid; t->sector = sector; t->bytes = bytes; t->action = what; t->device = bt->dev; t->error = error; t->pdu_len = pdu_len; if (pdu_len) memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); if (blk_tracer) { trace_buffer_unlock_commit(buffer, event, 0, pc); return; } } local_irq_restore(flags);} static struct dentry *blk_tree_root;static DEFINE_MUTEX(blk_tree_mutex); static void blk_trace_free(struct blk_trace *bt){ debugfs_remove(bt->msg_file); debugfs_remove(bt->dropped_file); relay_close(bt->rchan); debugfs_remove(bt->dir); free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt);} static void blk_trace_cleanup(struct blk_trace *bt){ blk_trace_free(bt); if (atomic_dec_and_test(&blk_probes_ref)) blk_unregister_tracepoints();} int blk_trace_remove(struct request_queue *q){ struct blk_trace *bt; bt = xchg(&q->blk_trace, NULL); if (!bt) return -EINVAL; if (bt->trace_state != Blktrace_running) blk_trace_cleanup(bt); return 0;}EXPORT_SYMBOL_GPL(blk_trace_remove); static int blk_dropped_open(struct inode *inode, struct file *filp){ filp->private_data = inode->i_private; return 0;} static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos){ struct blk_trace *bt = filp->private_data; char buf[16]; snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));} static const struct file_operations blk_dropped_fops = { .owner = THIS_MODULE, .open = blk_dropped_open, .read = blk_dropped_read,}; static int blk_msg_open(struct inode *inode, struct file *filp){ filp->private_data = inode->i_private; return 0;} static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, size_t count, loff_t *ppos){ char *msg; struct blk_trace *bt; if (count >= BLK_TN_MAX_MSG) return -EINVAL; msg = kmalloc(count + 1, GFP_KERNEL); if (msg == NULL) return -ENOMEM; if (copy_from_user(msg, buffer, count)) { kfree(msg); return -EFAULT; } msg[count] = '\0'; bt = filp->private_data; __trace_note_message(bt, "%s", msg); kfree(msg); return count;} static const struct file_operations blk_msg_fops = { .owner = THIS_MODULE, .open = blk_msg_open, .write = blk_msg_write,}; /* * Keep track of how many times we encountered a full subbuffer, to aid * the user space app in telling how many lost events there were. */static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, void *prev_subbuf, size_t prev_padding){ struct blk_trace *bt; if (!relay_buf_full(buf)) return 1; bt = buf->chan->private_data; atomic_inc(&bt->dropped); return 0;} static int blk_remove_buf_file_callback(struct dentry *dentry){ debugfs_remove(dentry); return 0;} static struct dentry *blk_create_buf_file_callback(const char *filename, struct dentry *parent, int mode, struct rchan_buf *buf, int *is_global){ return debugfs_create_file(filename, mode, parent, buf, &relay_file_operations);} static struct rchan_callbacks blk_relay_callbacks = { .subbuf_start = blk_subbuf_start_callback, .create_buf_file = blk_create_buf_file_callback, .remove_buf_file = blk_remove_buf_file_callback,}; static void blk_trace_setup_lba(struct blk_trace *bt, struct block_device *bdev){ struct hd_struct *part = NULL; if (bdev) part = bdev->bd_part; if (part) { bt->start_lba = part->start_sect; bt->end_lba = part->start_sect + part->nr_sects; } else { bt->start_lba = 0; bt->end_lba = -1ULL; }} /* * Setup everything required to start tracing */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 *old_bt, *bt = NULL; struct dentry *dir = NULL; int ret, i; if (!buts->buf_size || !buts->buf_nr) return -EINVAL; strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; /* * some device names have larger paths - convert the slashes * to underscores for this to work as expected */ for (i = 0; i < strlen(buts->name); i++) if (buts->name[i] == '/') buts->name[i] = '_'; 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; ret = -ENOENT; mutex_lock(&blk_tree_mutex); if (!blk_tree_root) { blk_tree_root = debugfs_create_dir("block", NULL); if (!blk_tree_root) { mutex_unlock(&blk_tree_mutex); goto err; } } mutex_unlock(&blk_tree_mutex); dir = debugfs_create_dir(buts->name, blk_tree_root); if (!dir) goto err; bt->dir = dir; bt->dev = dev; atomic_set(&bt->dropped, 0); ret = -EIO; bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); if (!bt->dropped_file) goto err; bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); if (!bt->msg_file) goto err; bt->rchan = relay_open("trace", dir, buts->buf_size, buts->buf_nr, &blk_relay_callbacks, bt); if (!bt->rchan) goto err; Lines 1–500 of 1845. 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/* * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #include <linux/kernel.h> #include <linux/blkdev.h> #include <linux/blktrace_api.h> #include <linux/percpu.h> #include <linux/init.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/debugfs.h> #include <linux/smp_lock.h> #include <linux/time.h> #include <linux/uaccess.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; /* Select an alternative, minimalistic output than the original one */ #define TRACE_BLK_OPT_CLASSIC 0x1 static struct tracer_opt blk_tracer_opts[] = { /* Default disable the minimalistic output */ { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, { } }; static struct tracer_flags blk_tracer_flags = { .val = 0, .opts = blk_tracer_opts, }; /* Global reference count of probes */ static atomic_t blk_probes_ref = ATOMIC_INIT(0); 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) { struct blk_io_trace *t; struct ring_buffer_event *event = NULL; struct ring_buffer *buffer = NULL; int pc = 0; int cpu = smp_processor_id(); bool blk_tracer = blk_tracer_enabled; if (blk_tracer) { buffer = blk_tr->buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + len, 0, pc); if (!event) return; t = ring_buffer_event_data(event); goto record_it; } if (!bt->rchan) return; t = relay_reserve(bt->rchan, sizeof(*t) + 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; t->pid = pid; t->cpu = cpu; t->pdu_len = len; memcpy((void *) t + sizeof(*t), data, len); if (blk_tracer) trace_buffer_unlock_commit(buffer, event, 0, pc); } } /* * Send out a notify for this process, if we haven't done so since a trace * started */ static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) { tsk->btrace_seq = blktrace_seq; trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); } static void trace_note_time(struct blk_trace *bt) { struct timespec now; unsigned long flags; u32 words[2]; getnstimeofday(&now); words[0] = now.tv_sec; words[1] = now.tv_nsec; local_irq_save(flags); trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); local_irq_restore(flags); } void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) { int n; va_list args; unsigned long flags; char *buf; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer_enabled)) return; local_irq_save(flags); buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); va_start(args, fmt); n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); va_end(args); trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(__trace_note_message); static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, pid_t pid) { if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) return 1; if (sector && (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_HARDBARRIER BLK_TC_BARRIER #define BLK_TC_RAHEAD BLK_TC_AHEAD /* The ilog2() calls fall out because they're constant */ #define MASK_TC_BIT(rw, __name) ((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, int rw, u32 what, int error, int pdu_len, void *pdu_data) { struct task_struct *tsk = current; struct ring_buffer_event *event = NULL; struct ring_buffer *buffer = NULL; struct blk_io_trace *t; unsigned long flags = 0; unsigned long *sequence; pid_t pid; int cpu, pc = 0; bool blk_tracer = blk_tracer_enabled; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) return; what |= ddir_act[rw & WRITE]; what |= MASK_TC_BIT(rw, HARDBARRIER); what |= MASK_TC_BIT(rw, SYNC); what |= MASK_TC_BIT(rw, RAHEAD); what |= MASK_TC_BIT(rw, META); what |= MASK_TC_BIT(rw, DISCARD); 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->buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + pdu_len, 0, pc); if (!event) return; t = ring_buffer_event_data(event); goto record_it; } /* * A word about the locking here - we disable interrupts to reserve * some space in the relay per-cpu buffer, to prevent an irq * from coming in and stepping on our toes. */ local_irq_save(flags); if (unlikely(tsk->btrace_seq != blktrace_seq)) trace_note_tsk(bt, tsk); t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); if (t) { sequence = per_cpu_ptr(bt->sequence, cpu); t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; t->sequence = ++(*sequence); t->time = ktime_to_ns(ktime_get()); record_it: /* * These two are not needed in ftrace as they are in the * generic trace_entry, filled by tracing_generic_entry_update, * but for the trace_event->bin() synthesizer benefit we do it * here too. */ t->cpu = cpu; t->pid = pid; t->sector = sector; t->bytes = bytes; t->action = what; t->device = bt->dev; t->error = error; t->pdu_len = pdu_len; if (pdu_len) memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); if (blk_tracer) { trace_buffer_unlock_commit(buffer, event, 0, pc); return; } } local_irq_restore(flags); } static struct dentry *blk_tree_root; static DEFINE_MUTEX(blk_tree_mutex); static void blk_trace_free(struct blk_trace *bt) { debugfs_remove(bt->msg_file); debugfs_remove(bt->dropped_file); relay_close(bt->rchan); debugfs_remove(bt->dir); free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt); } static void blk_trace_cleanup(struct blk_trace *bt) { blk_trace_free(bt); if (atomic_dec_and_test(&blk_probes_ref)) blk_unregister_tracepoints(); } int blk_trace_remove(struct request_queue *q) { struct blk_trace *bt; bt = xchg(&q->blk_trace, NULL); if (!bt) return -EINVAL; if (bt->trace_state != Blktrace_running) blk_trace_cleanup(bt); return 0; } EXPORT_SYMBOL_GPL(blk_trace_remove); static int blk_dropped_open(struct inode *inode, struct file *filp) { filp->private_data = inode->i_private; return 0; } static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { struct blk_trace *bt = filp->private_data; char buf[16]; snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); } static const struct file_operations blk_dropped_fops = { .owner = THIS_MODULE, .open = blk_dropped_open, .read = blk_dropped_read, }; static int blk_msg_open(struct inode *inode, struct file *filp) { filp->private_data = inode->i_private; return 0; } static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, size_t count, loff_t *ppos) { char *msg; struct blk_trace *bt; if (count >= BLK_TN_MAX_MSG) return -EINVAL; msg = kmalloc(count + 1, GFP_KERNEL); if (msg == NULL) return -ENOMEM; if (copy_from_user(msg, buffer, count)) { kfree(msg); return -EFAULT; } msg[count] = '\0'; bt = filp->private_data; __trace_note_message(bt, "%s", msg); kfree(msg); return count; } static const struct file_operations blk_msg_fops = { .owner = THIS_MODULE, .open = blk_msg_open, .write = blk_msg_write, }; /* * Keep track of how many times we encountered a full subbuffer, to aid * the user space app in telling how many lost events there were. */ static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, void *prev_subbuf, size_t prev_padding) { struct blk_trace *bt; if (!relay_buf_full(buf)) return 1; bt = buf->chan->private_data; atomic_inc(&bt->dropped); return 0; } static int blk_remove_buf_file_callback(struct dentry *dentry) { debugfs_remove(dentry); return 0; } static struct dentry *blk_create_buf_file_callback(const char *filename, struct dentry *parent, int mode, struct rchan_buf *buf, int *is_global) { return debugfs_create_file(filename, mode, parent, buf, &relay_file_operations); } static struct rchan_callbacks blk_relay_callbacks = { .subbuf_start = blk_subbuf_start_callback, .create_buf_file = blk_create_buf_file_callback, .remove_buf_file = blk_remove_buf_file_callback, }; static void blk_trace_setup_lba(struct blk_trace *bt, struct block_device *bdev) { struct hd_struct *part = NULL; if (bdev) part = bdev->bd_part; if (part) { bt->start_lba = part->start_sect; bt->end_lba = part->start_sect + part->nr_sects; } else { bt->start_lba = 0; bt->end_lba = -1ULL; } } /* * Setup everything required to start tracing */ 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 *old_bt, *bt = NULL; struct dentry *dir = NULL; int ret, i; if (!buts->buf_size || !buts->buf_nr) return -EINVAL; strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; /* * some device names have larger paths - convert the slashes * to underscores for this to work as expected */ for (i = 0; i < strlen(buts->name); i++) if (buts->name[i] == '/') buts->name[i] = '_'; 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; ret = -ENOENT; mutex_lock(&blk_tree_mutex); if (!blk_tree_root) { blk_tree_root = debugfs_create_dir("block", NULL); if (!blk_tree_root) { mutex_unlock(&blk_tree_mutex); goto err; } } mutex_unlock(&blk_tree_mutex); dir = debugfs_create_dir(buts->name, blk_tree_root); if (!dir) goto err; bt->dir = dir; bt->dev = dev; atomic_set(&bt->dropped, 0); ret = -EIO; bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); if (!bt->dropped_file) goto err; bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); if (!bt->msg_file) goto err; bt->rchan = relay_open("trace", dir, buts->buf_size, buts->buf_nr, &blk_relay_callbacks, bt); if (!bt->rchan) goto err;