07e4fead45
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 <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
/*
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* Copyright (C) 2017 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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#include <linux/kernel.h>
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#include <linux/blkdev.h>
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#include <linux/debugfs.h>
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#include <linux/blk-mq.h>
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#include "blk-mq.h"
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struct blk_mq_debugfs_attr {
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const char *name;
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umode_t mode;
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const struct file_operations *fops;
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};
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static struct dentry *block_debugfs_root;
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static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
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};
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static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
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};
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int blk_mq_debugfs_register(struct request_queue *q, const char *name)
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{
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if (!block_debugfs_root)
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return -ENOENT;
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q->debugfs_dir = debugfs_create_dir(name, block_debugfs_root);
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if (!q->debugfs_dir)
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goto err;
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if (blk_mq_debugfs_register_hctxs(q))
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goto err;
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return 0;
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err:
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blk_mq_debugfs_unregister(q);
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return -ENOMEM;
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}
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void blk_mq_debugfs_unregister(struct request_queue *q)
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{
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debugfs_remove_recursive(q->debugfs_dir);
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q->mq_debugfs_dir = NULL;
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q->debugfs_dir = NULL;
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}
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static int blk_mq_debugfs_register_ctx(struct request_queue *q,
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struct blk_mq_ctx *ctx,
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struct dentry *hctx_dir)
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{
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struct dentry *ctx_dir;
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char name[20];
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int i;
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snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
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ctx_dir = debugfs_create_dir(name, hctx_dir);
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if (!ctx_dir)
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return -ENOMEM;
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for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) {
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const struct blk_mq_debugfs_attr *attr;
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attr = &blk_mq_debugfs_ctx_attrs[i];
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if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx,
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attr->fops))
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return -ENOMEM;
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}
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return 0;
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}
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static int blk_mq_debugfs_register_hctx(struct request_queue *q,
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struct blk_mq_hw_ctx *hctx)
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{
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struct blk_mq_ctx *ctx;
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struct dentry *hctx_dir;
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char name[20];
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int i;
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snprintf(name, sizeof(name), "%u", hctx->queue_num);
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hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
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if (!hctx_dir)
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return -ENOMEM;
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for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) {
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const struct blk_mq_debugfs_attr *attr;
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attr = &blk_mq_debugfs_hctx_attrs[i];
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if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx,
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attr->fops))
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return -ENOMEM;
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}
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hctx_for_each_ctx(hctx, ctx, i) {
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if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
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return -ENOMEM;
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}
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return 0;
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}
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int blk_mq_debugfs_register_hctxs(struct request_queue *q)
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{
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struct blk_mq_hw_ctx *hctx;
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int i;
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if (!q->debugfs_dir)
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return -ENOENT;
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q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
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if (!q->mq_debugfs_dir)
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goto err;
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queue_for_each_hw_ctx(q, hctx, i) {
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if (blk_mq_debugfs_register_hctx(q, hctx))
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goto err;
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}
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return 0;
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err:
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blk_mq_debugfs_unregister_hctxs(q);
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return -ENOMEM;
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}
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void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
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{
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debugfs_remove_recursive(q->mq_debugfs_dir);
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q->mq_debugfs_dir = NULL;
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}
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void blk_mq_debugfs_init(void)
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{
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block_debugfs_root = debugfs_create_dir("block", NULL);
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}
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