On Tue, Apr 11, 2017 at 01:58:41PM -0700, Bart Van Assche wrote: > This new callback function will be used in the next patch to show > more information about SCSI requests. > > Signed-off-by: Bart Van Assche <[email protected]> > Cc: Omar Sandoval <[email protected]> > Cc: Hannes Reinecke <[email protected]> > --- > block/blk-mq-debugfs.c | 10 ++++++++-- > include/linux/blk-mq.h | 6 ++++++ > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c > index 161f30fc236f..6b28d92d4c0e 100644 > --- a/block/blk-mq-debugfs.c > +++ b/block/blk-mq-debugfs.c > @@ -316,7 +316,9 @@ static const char *const rqf_name[] = { > static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v) > { > struct request *rq = list_entry_rq(v); > + const struct blk_mq_ops *const mq_ops = rq->q->mq_ops; > const unsigned int op = rq->cmd_flags & REQ_OP_MASK; > + char drv_info[200]; > > seq_printf(m, "%p {.op=", rq); > if (op < ARRAY_SIZE(op_name) && op_name[op]) > @@ -329,8 +331,12 @@ static int blk_mq_debugfs_rq_show(struct seq_file *m, > void *v) > seq_puts(m, ", .rq_flags="); > blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name, > ARRAY_SIZE(rqf_name)); > - seq_printf(m, ", .tag=%d, .internal_tag=%d}\n", rq->tag, > - rq->internal_tag); > + if (mq_ops->show_rq) > + mq_ops->show_rq(rq, drv_info, sizeof(drv_info));
How about passing the seq_file to the callback instead of this arbitrarily-sized on-stack buffer?
