No commit message. Add one please.
On 2021/02/25 16:03, Chaitanya Kulkarni wrote:
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
> ---
> kernel/trace/blktrace.c | 113 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 113 insertions(+)
>
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index e45bbfcb5daf..4871934b9717 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -114,6 +114,52 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
> }
> }
>
> +static void trace_note_ext(struct blk_trace_ext *bt, pid_t pid, u64 action,
> + const void *data, size_t len, u64 cgid, u32 ioprio)
> +{
> + struct blk_io_trace_ext *t;
> + struct ring_buffer_event *event = NULL;
> + struct trace_buffer *buffer = NULL;
> + int pc = 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;
> + pc = preempt_count();
> + event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
> + sizeof(*t) + len + cgid_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 + cgid_len);
> + if (t) {
> + t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION_EXT;
> + t->time = ktime_to_ns(ktime_get());
> +record_it:
> + t->device = bt->dev;
> + t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
> + t->ioprio = ioprio;
> + 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, 0, pc);
> + }
> +}
> +
> /*
> * Send out a notify for this process, if we haven't done so since a trace
> * started
> @@ -132,6 +178,20 @@ static void trace_note_tsk(struct task_struct *tsk)
> spin_unlock_irqrestore(&running_trace_lock, flags);
> }
>
> +static void trace_note_tsk_ext(struct task_struct *tsk, u32 ioprio)
> +{
> + unsigned long flags;
> + struct blk_trace_ext *bt;
> +
> + tsk->btrace_seq = blktrace_seq;
> + spin_lock_irqsave(&running_trace_ext_lock, flags);
> + list_for_each_entry(bt, &running_trace_ext_list, running_ext_list) {
> + trace_note_ext(bt, tsk->pid, BLK_TN_PROCESS_EXT, tsk->comm,
> + sizeof(tsk->comm), 0, ioprio);
> + }
> + spin_unlock_irqrestore(&running_trace_ext_lock, flags);
> +}
> +
> static void trace_note_time(struct blk_trace *bt)
> {
> struct timespec64 now;
> @@ -148,6 +208,22 @@ static void trace_note_time(struct blk_trace *bt)
> local_irq_restore(flags);
> }
>
> +static void trace_note_time_ext(struct blk_trace_ext *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_ext(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0, 0);
> + local_irq_restore(flags);
> +}
> +
> void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
> const char *fmt, ...)
> {
> @@ -185,6 +261,43 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
> }
> EXPORT_SYMBOL_GPL(__trace_note_message);
>
> +void __trace_note_message_ext(struct blk_trace_ext *bt, struct blkcg *blkcg,
> + const char *fmt, ...)
> +{
> + int n;
> + va_list args;
> + unsigned long flags;
> + char *buf;
> +
> + 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);
> +
> + if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
> + blkcg = NULL;
> +#ifdef CONFIG_BLK_CGROUP
> + trace_note_ext(bt, 0, BLK_TN_MESSAGE_EXT, buf, n,
> + blkcg ? cgroup_id(blkcg->css.cgroup) : 1, 0);
> +#else
> + trace_note_ext(bt, 0, BLK_TN_MESSAGE_EXT, buf, n, 0, 0);
> +#endif
> + local_irq_restore(flags);
> +}
> +EXPORT_SYMBOL_GPL(__trace_note_message_ext);
> +
> static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
> pid_t pid)
> {
>
I fail to see why the xxx_ext functions need the different blk_trcae_ext
structure. It seems that everything should work with a modified blk_trace
structure. With such approach, a lot of the xxx_ext functions in here may not be
necessary at all. Simply change the interface of the existing note functions.
There are not that many call sites to change, right ?
--
Damien Le Moal
Western Digital Research
