From 85e0cbbb8a79537dbc465e9deb449a08b2b092a6 Mon Sep 17 00:00:00 2001 From: Luis Chamberlain Date: Fri, 19 Jun 2020 20:47:30 +0000 Subject: block: create the request_queue debugfs_dir on registration We were only creating the request_queue debugfs_dir only for make_request block drivers (multiqueue), but never for request-based block drivers. We did this as we were only creating non-blktrace additional debugfs files on that directory for make_request drivers. However, since blktrace *always* creates that directory anyway, we special-case the use of that directory on blktrace. Other than this being an eye-sore, this exposes request-based block drivers to the same debugfs fragile race that used to exist with make_request block drivers where if we start adding files onto that directory we can later run a race with a double removal of dentries on the directory if we don't deal with this carefully on blktrace. Instead, just simplify things by always creating the request_queue debugfs_dir on request_queue registration. Rename the mutex also to reflect the fact that this is used outside of the blktrace context. Signed-off-by: Luis Chamberlain Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'block/blk-sysfs.c') diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 561624d4cc4e..be67952e7be2 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "blk.h" #include "blk-mq.h" @@ -917,6 +918,9 @@ static void blk_release_queue(struct kobject *kobj) blk_mq_release(q); blk_trace_shutdown(q); + mutex_lock(&q->debugfs_mutex); + debugfs_remove_recursive(q->debugfs_dir); + mutex_unlock(&q->debugfs_mutex); if (queue_is_mq(q)) blk_mq_debugfs_unregister(q); @@ -989,6 +993,11 @@ int blk_register_queue(struct gendisk *disk) goto unlock; } + mutex_lock(&q->debugfs_mutex); + q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), + blk_debugfs_root); + mutex_unlock(&q->debugfs_mutex); + if (queue_is_mq(q)) { __blk_mq_register_dev(dev, q); blk_mq_debugfs_register(q); -- cgit v1.2.3-70-g09d2