From 07e4fead45e6e1932f0b960655ab554b6aab6a08 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:40 -0800 Subject: [PATCH] blk-mq: create debugfs directory tree In preparation for putting blk-mq debugging information in debugfs, create a directory tree mirroring the one in sysfs: # tree -d /sys/kernel/debug/block /sys/kernel/debug/block |-- nvme0n1 | `-- mq | |-- 0 | | `-- cpu0 | |-- 1 | | `-- cpu1 | |-- 2 | | `-- cpu2 | `-- 3 | `-- cpu3 `-- vda `-- mq `-- 0 |-- cpu0 |-- cpu1 |-- cpu2 `-- cpu3 Also add the scaffolding for the actual files that will go in here, either under the hardware queue or software queue directories. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/Makefile | 1 + block/blk-mq-debugfs.c | 152 +++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 8 +++ block/blk-mq.c | 2 + block/blk-mq.h | 33 +++++++++ include/linux/blkdev.h | 5 ++ 6 files changed, 201 insertions(+) create mode 100644 block/blk-mq-debugfs.c diff --git a/block/Makefile b/block/Makefile index 3ee0abd7205a..6cabe6bd2882 100644 --- a/block/Makefile +++ b/block/Makefile @@ -26,3 +26,4 @@ obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o obj-$(CONFIG_BLK_WBT) += blk-wbt.o +obj-$(CONFIG_DEBUG_FS) += blk-mq-debugfs.o diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c new file mode 100644 index 000000000000..01711bbf5ade --- /dev/null +++ b/block/blk-mq-debugfs.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2017 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include + +#include +#include "blk-mq.h" + +struct blk_mq_debugfs_attr { + const char *name; + umode_t mode; + const struct file_operations *fops; +}; + +static struct dentry *block_debugfs_root; + +static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { +}; + +static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { +}; + +int blk_mq_debugfs_register(struct request_queue *q, const char *name) +{ + if (!block_debugfs_root) + return -ENOENT; + + q->debugfs_dir = debugfs_create_dir(name, block_debugfs_root); + if (!q->debugfs_dir) + goto err; + + if (blk_mq_debugfs_register_hctxs(q)) + goto err; + + return 0; + +err: + blk_mq_debugfs_unregister(q); + return -ENOMEM; +} + +void blk_mq_debugfs_unregister(struct request_queue *q) +{ + debugfs_remove_recursive(q->debugfs_dir); + q->mq_debugfs_dir = NULL; + q->debugfs_dir = NULL; +} + +static int blk_mq_debugfs_register_ctx(struct request_queue *q, + struct blk_mq_ctx *ctx, + struct dentry *hctx_dir) +{ + struct dentry *ctx_dir; + char name[20]; + int i; + + snprintf(name, sizeof(name), "cpu%u", ctx->cpu); + ctx_dir = debugfs_create_dir(name, hctx_dir); + if (!ctx_dir) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) { + const struct blk_mq_debugfs_attr *attr; + + attr = &blk_mq_debugfs_ctx_attrs[i]; + if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx, + attr->fops)) + return -ENOMEM; + } + + return 0; +} + +static int blk_mq_debugfs_register_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx) +{ + struct blk_mq_ctx *ctx; + struct dentry *hctx_dir; + char name[20]; + int i; + + snprintf(name, sizeof(name), "%u", hctx->queue_num); + hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir); + if (!hctx_dir) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) { + const struct blk_mq_debugfs_attr *attr; + + attr = &blk_mq_debugfs_hctx_attrs[i]; + if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx, + attr->fops)) + return -ENOMEM; + } + + hctx_for_each_ctx(hctx, ctx, i) { + if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir)) + return -ENOMEM; + } + + return 0; +} + +int blk_mq_debugfs_register_hctxs(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + int i; + + if (!q->debugfs_dir) + return -ENOENT; + + q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir); + if (!q->mq_debugfs_dir) + goto err; + + queue_for_each_hw_ctx(q, hctx, i) { + if (blk_mq_debugfs_register_hctx(q, hctx)) + goto err; + } + + return 0; + +err: + blk_mq_debugfs_unregister_hctxs(q); + return -ENOMEM; +} + +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +{ + debugfs_remove_recursive(q->mq_debugfs_dir); + q->mq_debugfs_dir = NULL; +} + +void blk_mq_debugfs_init(void) +{ + block_debugfs_root = debugfs_create_dir("block", NULL); +} diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 2caecaa98e40..91b93ca1c1e0 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -468,6 +468,8 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) kobject_put(&hctx->kobj); } + blk_mq_debugfs_unregister(q); + kobject_uevent(&q->mq_kobj, KOBJ_REMOVE); kobject_del(&q->mq_kobj); kobject_put(&q->mq_kobj); @@ -517,6 +519,8 @@ int blk_mq_register_dev(struct device *dev, struct request_queue *q) kobject_uevent(&q->mq_kobj, KOBJ_ADD); + blk_mq_debugfs_register(q, kobject_name(&dev->kobj)); + queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); if (ret) @@ -542,6 +546,8 @@ void blk_mq_sysfs_unregister(struct request_queue *q) if (!q->mq_sysfs_init_done) return; + blk_mq_debugfs_unregister_hctxs(q); + queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); } @@ -554,6 +560,8 @@ int blk_mq_sysfs_register(struct request_queue *q) if (!q->mq_sysfs_init_done) return ret; + blk_mq_debugfs_register_hctxs(q); + queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); if (ret) diff --git a/block/blk-mq.c b/block/blk-mq.c index 84d13b5cafd0..ede835c2b08b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2799,6 +2799,8 @@ void blk_mq_enable_hotplug(void) static int __init blk_mq_init(void) { + blk_mq_debugfs_init(); + cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, blk_mq_hctx_notify_dead); diff --git a/block/blk-mq.h b/block/blk-mq.h index 0c7c034d9ddd..6c24b901acd7 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -78,6 +78,39 @@ extern int blk_mq_sysfs_register(struct request_queue *q); extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); +/* + * debugfs helpers + */ +#ifdef CONFIG_DEBUG_FS +void blk_mq_debugfs_init(void); +int blk_mq_debugfs_register(struct request_queue *q, const char *name); +void blk_mq_debugfs_unregister(struct request_queue *q); +int blk_mq_debugfs_register_hctxs(struct request_queue *q); +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q); +#else +static inline void blk_mq_debugfs_init(void) +{ +} + +int blk_mq_debugfs_register(struct request_queue *q, const char *name); +{ + return 0; +} + +void blk_mq_debugfs_unregister(struct request_queue *q) +{ +} + +int blk_mq_debugfs_register_hctxs(struct request_queue *q) +{ + return 0; +} + +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +{ +} +#endif + extern void blk_mq_rq_timed_out(struct request *req, bool reserved); void blk_mq_release(struct request_queue *q); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 25564857f5f8..0ee283f3cffe 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -571,6 +571,11 @@ struct request_queue { struct list_head tag_set_list; struct bio_set *bio_split; +#ifdef CONFIG_DEBUG_FS + struct dentry *debugfs_dir; + struct dentry *mq_debugfs_dir; +#endif + bool mq_sysfs_init_done; };