From 5cf9c91ba927119fc6606b938b1895bb2459d3bc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 14 Jun 2022 09:48:25 +0200 Subject: block: serialize all debugfs operations using q->debugfs_mutex Various places like I/O schedulers or the QOS infrastructure try to register debugfs files on demans, which can race with creating and removing the main queue debugfs directory. Use the existing debugfs_mutex to serialize all debugfs operations that rely on q->debugfs_dir or the directories hanging off it. To make the teardown code a little simpler declare all debugfs dentry pointers and not just the main one uncoditionally in blkdev.h. Move debugfs_mutex next to the dentries that it protects and document what it is used for. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220614074827.458955-3-hch@lst.de Signed-off-by: Jens Axboe --- kernel/trace/blktrace.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 10a32b0f2deb..fe04c6f96ca5 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -770,14 +770,11 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) **/ 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 -- cgit v1.2.3-58-ga151