On Thu, Apr 16, 2020 at 05:25:24AM +0000, Luis Chamberlain wrote: > On Thu, Apr 16, 2020 at 10:10:36AM +0800, Ming Lei wrote: > > In theory, multiple partitions can be traced concurrently, but looks > > it never works, so it won't cause trouble for multiple partition trace. > > > > One userspace visible change is that blktrace debugfs dir name is switched > > to disk name from partition name in case of partition trace, will it > > break some utilities? > > How is this possible, its not clear to me, we go from: > > - q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), > - blk_debugfs_root); > > To this: > > + q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), > + blk_debugfs_root); > > > Maybe I am overlooking something. Your patch removes the blktrace debugfs dir: do_blk_trace_setup() - dir = debugfs_lookup(buts->name, blk_debugfs_root); - if (!dir) - bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); - Then create blktrace attributes under the dir of q->debugfs_dir. However, buts->name could be one partition device name, but q->debugfs_dir has to be disk name. This change is visible to blktrace utilities. Thanks, Ming
