kernel/linux.git/block/blk-mq-debugfs.h, branch v7.0.10

blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()

2026-02-02T14:05:19+00:00

Because this helper is only used by iocost and iolatency, while they don't have debugfs entries. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static

2026-02-02T14:05:19+00:00

Because it's only used inside blk-mq-debugfs.c now. Reviewed-by: Nilay Shroff Signed-off-by: Yu Kuai Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos

2026-02-02T14:05:19+00:00

There is already a helper blk_mq_debugfs_register_rqos() to register one rqos, however this helper is called synchronously when the rqos is created with queue frozen. Prepare to fix possible deadlock to create blk-mq debugfs entries while queue is still frozen. Reviewed-by: Ming Lei Reviewed-by: Nilay Shroff Signed-off-by: Yu Kuai Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

block: Replace zone_wlock debugfs entry with zone_wplugs entry

2024-04-17T14:44:03+00:00

In preparation to completely remove zone write locking, replace the "zone_wlock" mq-debugfs entry that was listing zones that are write-locked with the zone_wplugs entry which lists the zones that currently have a write plug allocated. The write plug information provided is: the zone number, the zone write plug flags, the zone write plug write pointer offset and the number of BIOs currently waiting for execution in the zone write plug BIO list. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-26-dlemoal@kernel.org Signed-off-by: Jens Axboe

block: Move zone related debugfs attribute to blk-zoned.c

2024-04-17T14:44:03+00:00

block/blk-mq-debugfs-zone.c contains a single debugfs attribute function. Defining this outside of block/blk-zoned.c does not really help in any way, so move this zone related debugfs attribute to block/blk-zoned.c and delete block/blk-mq-debugfs-zone.c. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-25-dlemoal@kernel.org Signed-off-by: Jens Axboe

block: remove per-disk debugfs files in blk_unregister_queue

2022-06-17T13:31:05+00:00

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 Link: https://lore.kernel.org/r/20220614074827.458955-4-hch@lst.de Signed-off-by: Jens Axboe

block: serialize all debugfs operations using q->debugfs_mutex

2022-06-17T13:31:05+00:00

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

blk-mq: manage hctx map via xarray

2022-03-09T02:39:38+00:00

First code becomes more clean by switching to xarray from plain array. Second use-after-free on q->queue_hw_ctx can be fixed because queue_for_each_hw_ctx() may be run when updating nr_hw_queues is in-progress. With this patch, q->hctx_table is defined as xarray, and this structure will share same lifetime with request queue, so queue_for_each_hw_ctx() can use q->hctx_table to lookup hctx reliably. Reported-by: Yu Kuai Signed-off-by: Ming Lei Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220308073219.91173-7-ming.lei@redhat.com [axboe: fix blk_mq_hw_ctx forward declaration] Signed-off-by: Jens Axboe

blk-mq: no need to check return value of debugfs_create functions

2019-06-13T09:00:30+00:00

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. When all of these checks are cleaned up, lots of the functions used in the blk-mq-debugfs code can now return void, as no need to check the return value of them either. Overall, this ends up cleaning up the code and making it smaller, always a nice win. Cc: Jens Axboe Cc: linux-block@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Jens Axboe

blk-mq-debugfs: support rq_qos

2018-12-17T02:53:47+00:00

blk-mq-debugfs has been proved as very helpful for debug some tough issues, such as IO hang. We have seen blk-wbt related IO hang several times, even inside Red Hat BZ, there is such report not sovled yet, so this patch adds support debugfs on rq_qos. Cc: Bart Van Assche Cc: Omar Sandoval Cc: Christoph Hellwig Cc: Josef Bacik Signed-off-by: Ming Lei Signed-off-by: Jens Axboe