// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
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*
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*/
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|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/blkdev.h>
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#include <linux/blktrace_api.h>
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#include <linux/percpu.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/debugfs.h>
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#include <linux/export.h>
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#include <linux/time.h>
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#include <linux/uaccess.h>
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#include <linux/list.h>
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#include <linux/blk-cgroup.h>
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|
#include "../../block/blk.h"
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|
#include <trace/events/block.h>
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|
#include "trace_output.h"
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|
#ifdef CONFIG_BLK_DEV_IO_TRACE
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|
static unsigned int blktrace_seq __read_mostly = 1;
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|
static struct trace_array *blk_tr;
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static bool blk_tracer_enabled __read_mostly;
|
|
static LIST_HEAD(running_trace_list);
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock);
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/* Select an alternative, minimalistic output than the original one */
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#define TRACE_BLK_OPT_CLASSIC 0x1
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#define TRACE_BLK_OPT_CGROUP 0x2
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#define TRACE_BLK_OPT_CGNAME 0x4
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|
static struct tracer_opt blk_tracer_opts[] = {
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/* Default disable the minimalistic output */
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{ TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
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#ifdef CONFIG_BLK_CGROUP
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{ TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) },
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{ TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) },
|
#endif
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{ }
|
};
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|
static struct tracer_flags blk_tracer_flags = {
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.val = 0,
|
.opts = blk_tracer_opts,
|
};
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|
/* Global reference count of probes */
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static DEFINE_MUTEX(blk_probe_mutex);
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static int blk_probes_ref;
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|
static void blk_register_tracepoints(void);
|
static void blk_unregister_tracepoints(void);
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/*
|
* Send out a notify message.
|
*/
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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;
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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;
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t = ring_buffer_event_data(event);
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goto record_it;
|
}
|
|
if (!bt->rchan)
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return;
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|
t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len);
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if (t) {
|
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
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t->time = ktime_to_ns(ktime_get());
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record_it:
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t->device = bt->dev;
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t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
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t->pid = pid;
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t->cpu = cpu;
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t->pdu_len = len + cgid_len;
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if (cgid_len)
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memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
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memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
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if (blk_tracer)
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trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
|
}
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}
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/*
|
* Send out a notify for this process, if we haven't done so since a trace
|
* started
|
*/
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static void trace_note_tsk(struct task_struct *tsk)
|
{
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unsigned long flags;
|
struct blk_trace *bt;
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|
tsk->btrace_seq = blktrace_seq;
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spin_lock_irqsave(&running_trace_lock, flags);
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list_for_each_entry(bt, &running_trace_list, running_list) {
|
trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
|
sizeof(tsk->comm), 0);
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}
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spin_unlock_irqrestore(&running_trace_lock, flags);
|
}
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static void trace_note_time(struct blk_trace *bt)
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{
|
struct timespec64 now;
|
unsigned long flags;
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u32 words[2];
|
|
/* need to check user space to see if this breaks in y2038 or y2106 */
|
ktime_get_real_ts64(&now);
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words[0] = (u32)now.tv_sec;
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words[1] = now.tv_nsec;
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|
local_irq_save(flags);
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trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0);
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local_irq_restore(flags);
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}
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void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
|
const char *fmt, ...)
|
{
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int n;
|
va_list args;
|
unsigned long flags;
|
char *buf;
|
|
if (unlikely(bt->trace_state != Blktrace_running &&
|
!blk_tracer_enabled))
|
return;
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|
/*
|
* If the BLK_TC_NOTIFY action mask isn't set, don't send any note
|
* message to the trace.
|
*/
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if (!(bt->act_mask & BLK_TC_NOTIFY))
|
return;
|
|
local_irq_save(flags);
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buf = this_cpu_ptr(bt->msg_data);
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va_start(args, fmt);
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n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
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va_end(args);
|
|
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
|
blkcg = NULL;
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#ifdef CONFIG_BLK_CGROUP
|
trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n,
|
blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
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#else
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trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, 0);
|
#endif
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL_GPL(__trace_note_message);
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static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
|
pid_t pid)
|
{
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if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
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return 1;
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if (sector && (sector < bt->start_lba || sector > bt->end_lba))
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return 1;
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if (bt->pid && pid != bt->pid)
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return 1;
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|
return 0;
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}
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|
/*
|
* Data direction bit lookup
|
*/
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static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
|
BLK_TC_ACT(BLK_TC_WRITE) };
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|
#define BLK_TC_RAHEAD BLK_TC_AHEAD
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#define BLK_TC_PREFLUSH BLK_TC_FLUSH
|
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/* The ilog2() calls fall out because they're constant */
|
#define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
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(ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
|
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/*
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* The worker for the various blk_add_trace*() types. Fills out a
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* blk_io_trace structure and places it in a per-cpu subbuffer.
|
*/
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static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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int op, int op_flags, u32 what, int error, int pdu_len,
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void *pdu_data, u64 cgid)
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{
|
struct task_struct *tsk = current;
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struct ring_buffer_event *event = NULL;
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struct trace_buffer *buffer = NULL;
|
struct blk_io_trace *t;
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unsigned long flags = 0;
|
unsigned long *sequence;
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unsigned int trace_ctx = 0;
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pid_t pid;
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int cpu;
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bool blk_tracer = blk_tracer_enabled;
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ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
|
|
if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
|
return;
|
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what |= ddir_act[op_is_write(op) ? WRITE : READ];
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what |= MASK_TC_BIT(op_flags, SYNC);
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what |= MASK_TC_BIT(op_flags, RAHEAD);
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what |= MASK_TC_BIT(op_flags, META);
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what |= MASK_TC_BIT(op_flags, PREFLUSH);
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what |= MASK_TC_BIT(op_flags, FUA);
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if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)
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what |= BLK_TC_ACT(BLK_TC_DISCARD);
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if (op == REQ_OP_FLUSH)
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what |= BLK_TC_ACT(BLK_TC_FLUSH);
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if (cgid)
|
what |= __BLK_TA_CGROUP;
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pid = tsk->pid;
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if (act_log_check(bt, what, sector, pid))
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return;
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cpu = raw_smp_processor_id();
|
|
if (blk_tracer) {
|
tracing_record_cmdline(current);
|
|
buffer = blk_tr->array_buffer.buffer;
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trace_ctx = tracing_gen_ctx_flags(0);
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event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
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sizeof(*t) + pdu_len + cgid_len,
|
trace_ctx);
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if (!event)
|
return;
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t = ring_buffer_event_data(event);
|
goto record_it;
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}
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if (unlikely(tsk->btrace_seq != blktrace_seq))
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trace_note_tsk(tsk);
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|
/*
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* A word about the locking here - we disable interrupts to reserve
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* some space in the relay per-cpu buffer, to prevent an irq
|
* from coming in and stepping on our toes.
|
*/
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local_irq_save(flags);
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t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len);
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if (t) {
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sequence = per_cpu_ptr(bt->sequence, cpu);
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t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
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t->sequence = ++(*sequence);
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t->time = ktime_to_ns(ktime_get());
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record_it:
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/*
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* These two are not needed in ftrace as they are in the
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* generic trace_entry, filled by tracing_generic_entry_update,
|
* but for the trace_event->bin() synthesizer benefit we do it
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* here too.
|
*/
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t->cpu = cpu;
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t->pid = pid;
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t->sector = sector;
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t->bytes = bytes;
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t->action = what;
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t->device = bt->dev;
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t->error = error;
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t->pdu_len = pdu_len + cgid_len;
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|
if (cgid_len)
|
memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
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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;
|
}
|
}
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|
local_irq_restore(flags);
|
}
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|
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);
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free_percpu(bt->sequence);
|
free_percpu(bt->msg_data);
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kfree(bt);
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}
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|
static void get_probe_ref(void)
|
{
|
mutex_lock(&blk_probe_mutex);
|
if (++blk_probes_ref == 1)
|
blk_register_tracepoints();
|
mutex_unlock(&blk_probe_mutex);
|
}
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|
static void put_probe_ref(void)
|
{
|
mutex_lock(&blk_probe_mutex);
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if (!--blk_probes_ref)
|
blk_unregister_tracepoints();
|
mutex_unlock(&blk_probe_mutex);
|
}
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|
static void blk_trace_cleanup(struct blk_trace *bt)
|
{
|
synchronize_rcu();
|
blk_trace_free(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;
|
|
if (bt->trace_state != Blktrace_running)
|
blk_trace_cleanup(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;
|
__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 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
|
*/
|
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;
|
bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
|
&blk_dropped_fops);
|
|
bt->msg_file = 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(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)
|
{
|
int ret;
|
struct blk_trace *bt;
|
|
bt = rcu_dereference_protected(q->blk_trace,
|
lockdep_is_held(&q->debugfs_mutex));
|
if (bt == NULL)
|
return -EINVAL;
|
|
/*
|
* For starting a trace, we can transition from a setup or stopped
|
* trace. For stopping a trace, the state must be running
|
*/
|
ret = -EINVAL;
|
if (start) {
|
if (bt->trace_state == Blktrace_setup ||
|
bt->trace_state == Blktrace_stopped) {
|
blktrace_seq++;
|
smp_mb();
|
bt->trace_state = Blktrace_running;
|
spin_lock_irq(&running_trace_lock);
|
list_add(&bt->running_list, &running_trace_list);
|
spin_unlock_irq(&running_trace_lock);
|
|
trace_note_time(bt);
|
ret = 0;
|
}
|
} else {
|
if (bt->trace_state == Blktrace_running) {
|
bt->trace_state = Blktrace_stopped;
|
spin_lock_irq(&running_trace_lock);
|
list_del_init(&bt->running_list);
|
spin_unlock_irq(&running_trace_lock);
|
relay_flush(bt->rchan);
|
ret = 0;
|
}
|
}
|
|
return ret;
|
}
|
|
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:
|
bdevname(bdev, b);
|
ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
|
break;
|
#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
|
case BLKTRACESETUP32:
|
bdevname(bdev, b);
|
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)
|
{
|
mutex_lock(&q->debugfs_mutex);
|
if (rcu_dereference_protected(q->blk_trace,
|
lockdep_is_held(&q->debugfs_mutex))) {
|
__blk_trace_startstop(q, 0);
|
__blk_trace_remove(q);
|
}
|
|
mutex_unlock(&q->debugfs_mutex);
|
}
|
|
#ifdef CONFIG_BLK_CGROUP
|
static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
|
{
|
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;
|
|
if (!bio->bi_blkg)
|
return 0;
|
return cgroup_id(bio_blkcg(bio)->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_queue *q, struct request *rq)
|
{
|
if (!rq->bio)
|
return 0;
|
/* Use the first bio */
|
return blk_trace_bio_get_cgid(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, int 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, req_op(rq),
|
rq->cmd_flags, what, error, 0, NULL, cgid);
|
rcu_read_unlock();
|
}
|
|
static void blk_add_trace_rq_insert(void *ignore,
|
struct request_queue *q, struct request *rq)
|
{
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
|
blk_trace_request_get_cgid(q, rq));
|
}
|
|
static void blk_add_trace_rq_issue(void *ignore,
|
struct request_queue *q, struct request *rq)
|
{
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
|
blk_trace_request_get_cgid(q, rq));
|
}
|
|
static void blk_add_trace_rq_merge(void *ignore,
|
struct request_queue *q, struct request *rq)
|
{
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
|
blk_trace_request_get_cgid(q, rq));
|
}
|
|
static void blk_add_trace_rq_requeue(void *ignore,
|
struct request_queue *q,
|
struct request *rq)
|
{
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
|
blk_trace_request_get_cgid(q, rq));
|
}
|
|
static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
|
int error, unsigned int nr_bytes)
|
{
|
blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
|
blk_trace_request_get_cgid(rq->q, 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_op(bio), 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 request_queue *q, struct bio *bio)
|
{
|
blk_add_trace_bio(q, 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 request_queue *q,
|
struct request *rq,
|
struct bio *bio)
|
{
|
blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
|
}
|
|
static void blk_add_trace_bio_frontmerge(void *ignore,
|
struct request_queue *q,
|
struct request *rq,
|
struct bio *bio)
|
{
|
blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
|
}
|
|
static void blk_add_trace_bio_queue(void *ignore,
|
struct request_queue *q, struct bio *bio)
|
{
|
blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
|
}
|
|
static void blk_add_trace_getrq(void *ignore,
|
struct request_queue *q,
|
struct bio *bio, int rw)
|
{
|
if (bio)
|
blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
|
else {
|
struct blk_trace *bt;
|
|
rcu_read_lock();
|
bt = rcu_dereference(q->blk_trace);
|
if (bt)
|
__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
|
NULL, 0);
|
rcu_read_unlock();
|
}
|
}
|
|
|
static void blk_add_trace_sleeprq(void *ignore,
|
struct request_queue *q,
|
struct bio *bio, int rw)
|
{
|
if (bio)
|
blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
|
else {
|
struct blk_trace *bt;
|
|
rcu_read_lock();
|
bt = rcu_dereference(q->blk_trace);
|
if (bt)
|
__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ,
|
0, 0, NULL, 0);
|
rcu_read_unlock();
|
}
|
}
|
|
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, 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, 0, what, 0, sizeof(rpdu), &rpdu, 0);
|
}
|
rcu_read_unlock();
|
}
|
|
static void blk_add_trace_split(void *ignore,
|
struct request_queue *q, struct bio *bio,
|
unsigned int pdu)
|
{
|
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_op(bio), 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)
|
* @q: queue the io is for
|
* @bio: the source bio
|
* @dev: target device
|
* @from: source sector
|
*
|
* Description:
|
* Device mapper or raid target sometimes need to split a bio because
|
* it spans a stripe (or similar). Add a trace for that action.
|
*
|
**/
|
static void blk_add_trace_bio_remap(void *ignore,
|
struct request_queue *q, struct bio *bio,
|
dev_t dev, sector_t from)
|
{
|
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_op(bio), 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)
|
* @q: queue the io is for
|
* @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_queue *q,
|
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(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->rq_disk));
|
r.sector_from = cpu_to_be64(from);
|
|
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
|
rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
|
sizeof(r), &r, blk_trace_request_get_cgid(q, rq));
|
rcu_read_unlock();
|
}
|
|
/**
|
* blk_add_driver_data - Add binary message with driver-specific data
|
* @q: queue the io is for
|
* @rq: io request
|
* @data: driver-specific data
|
* @len: length of driver-specific data
|
*
|
* Description:
|
* Some drivers might want to write driver-specific data per request.
|
*
|
**/
|
void blk_add_driver_data(struct request_queue *q,
|
struct request *rq,
|
void *data, size_t len)
|
{
|
struct blk_trace *bt;
|
|
rcu_read_lock();
|
bt = rcu_dereference(q->blk_trace);
|
if (likely(!bt)) {
|
rcu_read_unlock();
|
return;
|
}
|
|
__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
|
BLK_TA_DRV_DATA, 0, len, data,
|
blk_trace_request_get_cgid(q, 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_sleeprq(blk_add_trace_sleeprq, 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_sleeprq(blk_add_trace_sleeprq, 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.
|
*
|
* Regarldess 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 zeroes 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 (!(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;
|
|
if (bt->trace_state == Blktrace_running) {
|
bt->trace_state = Blktrace_stopped;
|
spin_lock_irq(&running_trace_lock);
|
list_del_init(&bt->running_list);
|
spin_unlock_irq(&running_trace_lock);
|
relay_flush(bt->rchan);
|
}
|
|
put_probe_ref();
|
synchronize_rcu();
|
blk_trace_free(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(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 struct request_queue *blk_trace_get_queue(struct block_device *bdev)
|
{
|
if (bdev->bd_disk == NULL)
|
return NULL;
|
|
return bdev_get_queue(bdev);
|
}
|
|
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
struct block_device *bdev = bdget_part(dev_to_part(dev));
|
struct request_queue *q;
|
struct blk_trace *bt;
|
ssize_t ret = -ENXIO;
|
|
if (bdev == NULL)
|
goto out;
|
|
q = blk_trace_get_queue(bdev);
|
if (q == NULL)
|
goto out_bdput;
|
|
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);
|
out_bdput:
|
bdput(bdev);
|
out:
|
return ret;
|
}
|
|
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
|
struct device_attribute *attr,
|
const char *buf, size_t count)
|
{
|
struct block_device *bdev;
|
struct request_queue *q;
|
struct 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;
|
|
ret = -ENXIO;
|
bdev = bdget_part(dev_to_part(dev));
|
if (bdev == NULL)
|
goto out;
|
|
q = blk_trace_get_queue(bdev);
|
if (q == NULL)
|
goto out_bdput;
|
|
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_bdput:
|
bdput(bdev);
|
out:
|
return ret ? ret : count;
|
}
|
|
int blk_trace_init_sysfs(struct device *dev)
|
{
|
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
|
}
|
|
void blk_trace_remove_sysfs(struct device *dev)
|
{
|
sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
|
}
|
|
#endif /* CONFIG_BLK_DEV_IO_TRACE */
|
|
#ifdef CONFIG_EVENT_TRACING
|
|
void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
|
{
|
int i = 0;
|
|
if (op & REQ_PREFLUSH)
|
rwbs[i++] = 'F';
|
|
switch (op & REQ_OP_MASK) {
|
case REQ_OP_WRITE:
|
case REQ_OP_WRITE_SAME:
|
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 (op & REQ_FUA)
|
rwbs[i++] = 'F';
|
if (op & REQ_RAHEAD)
|
rwbs[i++] = 'A';
|
if (op & REQ_SYNC)
|
rwbs[i++] = 'S';
|
if (op & REQ_META)
|
rwbs[i++] = 'M';
|
|
rwbs[i] = '\0';
|
}
|
EXPORT_SYMBOL_GPL(blk_fill_rwbs);
|
|
#endif /* CONFIG_EVENT_TRACING */
|
