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authorChristoph Hellwig <hch@lst.de>2022-06-14 09:48:25 +0200
committerJens Axboe <axboe@kernel.dk>2022-06-17 07:31:05 -0600
commit5cf9c91ba927119fc6606b938b1895bb2459d3bc (patch)
treec6d3d7b1806f35e8fff9c439285324c6feeddad5 /kernel
parent50e34d78815e474d410f342fbe783b18192ca518 (diff)
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 <hch@lst.de> Link: https://lore.kernel.org/r/20220614074827.458955-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/blktrace.c3
1 files changed, 0 insertions, 3 deletions
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