linux/block/blk-mq-debugfs.h
Christoph Hellwig 99d055b4fd block: remove per-disk debugfs files in blk_unregister_queue
The block debugfs files are created in blk_register_queue, which is
called by add_disk and use a naming scheme based on the disk_name.
After del_gendisk returns that name can be reused and thus we must not
leave these debugfs files around, otherwise the kernel is unhappy
and spews messages like:

	Directory XXXXX with parent 'block' already present!

and the newly created devices will not have working debugfs files.

Move the unregistration to blk_unregister_queue instead (which matches
the sysfs unregistration) to make sure the debugfs life time rules match
those of the disk name.

As part of the move also make sure the whole debugfs unregistration is
inside a single debugfs_mutex critical section.

Note that this breaks blktests block/002, which checks that the debugfs
directory has not been removed while blktests is running, but that
particular check should simply be removed from the test case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220614074827.458955-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-17 07:31:05 -06:00

95 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef INT_BLK_MQ_DEBUGFS_H
#define INT_BLK_MQ_DEBUGFS_H
#ifdef CONFIG_BLK_DEBUG_FS
#include <linux/seq_file.h>
struct blk_mq_hw_ctx;
struct blk_mq_debugfs_attr {
const char *name;
umode_t mode;
int (*show)(void *, struct seq_file *);
ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
/* Set either .show or .seq_ops. */
const struct seq_operations *seq_ops;
};
int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq);
int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);
void blk_mq_debugfs_register(struct request_queue *q);
void blk_mq_debugfs_register_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_register_hctxs(struct request_queue *q);
void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
void blk_mq_debugfs_register_sched(struct request_queue *q);
void blk_mq_debugfs_unregister_sched(struct request_queue *q);
void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_register_rqos(struct rq_qos *rqos);
void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos);
#else
static inline void blk_mq_debugfs_register(struct request_queue *q)
{
}
static inline void blk_mq_debugfs_register_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx)
{
}
static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
}
static inline void blk_mq_debugfs_register_hctxs(struct request_queue *q)
{
}
static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
{
}
static inline void blk_mq_debugfs_register_sched(struct request_queue *q)
{
}
static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
{
}
static inline void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx)
{
}
static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
{
}
static inline void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
{
}
static inline void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
{
}
#endif
#ifdef CONFIG_BLK_DEBUG_FS_ZONED
int queue_zone_wlock_show(void *data, struct seq_file *m);
#else
static inline int queue_zone_wlock_show(void *data, struct seq_file *m)
{
return 0;
}
#endif
#endif