aleph/lkl_linux
1
0
Fork 0
mirror of https://github.com/lkl/linux.git synced 2025-12-19 08:03:01 +09:00
Code Issues Packages Projects Releases Wiki Activity

block: serialize all debugfs operations using q->debugfs_mutex

Browse Source 
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>
This commit is contained in:
Christoph Hellwig
2022-06-14 09:48:25 +02:00
committed by Jens Axboe
parent 50e34d7881
commit 5cf9c91ba9
8 changed files with 52 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
block/blk-mq-debugfs.c
View File

@@ -711,11 +711,6 @@ void blk_mq_debugfs_register(struct request_queue *q)
}
}
void blk_mq_debugfs_unregister(struct request_queue *q)
{
q->sched_debugfs_dir = NULL;
}
static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
struct blk_mq_ctx *ctx)
{
@@ -746,6 +741,8 @@ void blk_mq_debugfs_register_hctx(struct request_queue *q,
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
if (!hctx->queue->debugfs_dir)
return;
debugfs_remove_recursive(hctx->debugfs_dir);
hctx->sched_debugfs_dir = NULL;
hctx->debugfs_dir = NULL;
@@ -773,6 +770,8 @@ void blk_mq_debugfs_register_sched(struct request_queue *q)
{
struct elevator_type *e = q->elevator->type;
lockdep_assert_held(&q->debugfs_mutex);
/*
* If the parent directory has not been created yet, return, we will be
* called again later on and the directory/files will be created then.
@@ -790,6 +789,8 @@ void blk_mq_debugfs_register_sched(struct request_queue *q)
void blk_mq_debugfs_unregister_sched(struct request_queue *q)
{
lockdep_assert_held(&q->debugfs_mutex);
debugfs_remove_recursive(q->sched_debugfs_dir);
q->sched_debugfs_dir = NULL;
}
@@ -811,6 +812,10 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
{
lockdep_assert_held(&rqos->q->debugfs_mutex);
if (!rqos->q->debugfs_dir)
return;
debugfs_remove_recursive(rqos->debugfs_dir);
rqos->debugfs_dir = NULL;
}
@@ -820,6 +825,8 @@ void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
struct request_queue *q = rqos->q;
const char *dir_name = rq_qos_id_to_name(rqos->id);
lockdep_assert_held(&q->debugfs_mutex);
if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
return;
@@ -835,6 +842,8 @@ void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
{
lockdep_assert_held(&q->debugfs_mutex);
debugfs_remove_recursive(q->rqos_debugfs_dir);
q->rqos_debugfs_dir = NULL;
}
@@ -844,6 +853,8 @@ void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
{
struct elevator_type *e = q->elevator->type;
lockdep_assert_held(&q->debugfs_mutex);
/*
* If the parent debugfs directory has not been created yet, return;
* We will be called again later on with appropriate parent debugfs
@@ -863,6 +874,10 @@ void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
{
lockdep_assert_held(&hctx->queue->debugfs_mutex);
if (!hctx->queue->debugfs_dir)
return;
debugfs_remove_recursive(hctx->sched_debugfs_dir);
hctx->sched_debugfs_dir = NULL;
}