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d2c9be89f8
8962842ca5("blk-mq: avoid sysfs buffer overflow with too many CPU cores") avoids sysfs buffer overflow, and reserves one character for line break. However, the last snprintf() doesn't get correct 'size' parameter passed in, so fixed it. Fixes:8962842ca5("blk-mq: avoid sysfs buffer overflow with too many CPU cores") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
385 lines
8.4 KiB
C
385 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/backing-dev.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#include <linux/smp.h>
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#include <linux/blk-mq.h>
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#include "blk.h"
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#include "blk-mq.h"
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#include "blk-mq-tag.h"
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static void blk_mq_sysfs_release(struct kobject *kobj)
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{
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struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
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free_percpu(ctxs->queue_ctx);
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kfree(ctxs);
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}
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static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
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{
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struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
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/* ctx->ctxs won't be released until all ctx are freed */
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kobject_put(&ctx->ctxs->kobj);
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}
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static void blk_mq_hw_sysfs_release(struct kobject *kobj)
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{
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struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
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kobj);
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cancel_delayed_work_sync(&hctx->run_work);
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if (hctx->flags & BLK_MQ_F_BLOCKING)
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cleanup_srcu_struct(hctx->srcu);
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blk_free_flush_queue(hctx->fq);
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sbitmap_free(&hctx->ctx_map);
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free_cpumask_var(hctx->cpumask);
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kfree(hctx->ctxs);
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kfree(hctx);
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}
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struct blk_mq_ctx_sysfs_entry {
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struct attribute attr;
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ssize_t (*show)(struct blk_mq_ctx *, char *);
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ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
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};
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struct blk_mq_hw_ctx_sysfs_entry {
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struct attribute attr;
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ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
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ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
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};
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static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
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char *page)
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{
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struct blk_mq_ctx_sysfs_entry *entry;
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struct blk_mq_ctx *ctx;
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struct request_queue *q;
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ssize_t res;
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entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
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ctx = container_of(kobj, struct blk_mq_ctx, kobj);
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q = ctx->queue;
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if (!entry->show)
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return -EIO;
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mutex_lock(&q->sysfs_lock);
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res = entry->show(ctx, page);
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mutex_unlock(&q->sysfs_lock);
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return res;
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}
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static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
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const char *page, size_t length)
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{
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struct blk_mq_ctx_sysfs_entry *entry;
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struct blk_mq_ctx *ctx;
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struct request_queue *q;
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ssize_t res;
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entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
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ctx = container_of(kobj, struct blk_mq_ctx, kobj);
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q = ctx->queue;
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if (!entry->store)
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return -EIO;
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mutex_lock(&q->sysfs_lock);
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res = entry->store(ctx, page, length);
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mutex_unlock(&q->sysfs_lock);
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return res;
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}
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static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
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struct attribute *attr, char *page)
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{
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struct blk_mq_hw_ctx_sysfs_entry *entry;
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struct blk_mq_hw_ctx *hctx;
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struct request_queue *q;
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ssize_t res;
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entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
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hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
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q = hctx->queue;
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if (!entry->show)
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return -EIO;
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mutex_lock(&q->sysfs_lock);
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res = entry->show(hctx, page);
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mutex_unlock(&q->sysfs_lock);
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return res;
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}
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static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
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struct attribute *attr, const char *page,
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size_t length)
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{
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struct blk_mq_hw_ctx_sysfs_entry *entry;
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struct blk_mq_hw_ctx *hctx;
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struct request_queue *q;
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ssize_t res;
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entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
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hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
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q = hctx->queue;
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if (!entry->store)
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return -EIO;
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mutex_lock(&q->sysfs_lock);
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res = entry->store(hctx, page, length);
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mutex_unlock(&q->sysfs_lock);
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return res;
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}
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static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
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char *page)
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{
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return sprintf(page, "%u\n", hctx->tags->nr_tags);
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}
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static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
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char *page)
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{
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return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
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}
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static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
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{
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const size_t size = PAGE_SIZE - 1;
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unsigned int i, first = 1;
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int ret = 0, pos = 0;
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for_each_cpu(i, hctx->cpumask) {
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if (first)
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ret = snprintf(pos + page, size - pos, "%u", i);
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else
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ret = snprintf(pos + page, size - pos, ", %u", i);
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if (ret >= size - pos)
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break;
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first = 0;
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pos += ret;
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}
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ret = snprintf(pos + page, size + 1 - pos, "\n");
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return pos + ret;
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}
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static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
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.attr = {.name = "nr_tags", .mode = 0444 },
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.show = blk_mq_hw_sysfs_nr_tags_show,
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};
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static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
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.attr = {.name = "nr_reserved_tags", .mode = 0444 },
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.show = blk_mq_hw_sysfs_nr_reserved_tags_show,
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};
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static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
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.attr = {.name = "cpu_list", .mode = 0444 },
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.show = blk_mq_hw_sysfs_cpus_show,
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};
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static struct attribute *default_hw_ctx_attrs[] = {
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&blk_mq_hw_sysfs_nr_tags.attr,
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&blk_mq_hw_sysfs_nr_reserved_tags.attr,
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&blk_mq_hw_sysfs_cpus.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(default_hw_ctx);
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static const struct sysfs_ops blk_mq_sysfs_ops = {
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.show = blk_mq_sysfs_show,
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.store = blk_mq_sysfs_store,
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};
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static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
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.show = blk_mq_hw_sysfs_show,
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.store = blk_mq_hw_sysfs_store,
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};
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static struct kobj_type blk_mq_ktype = {
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.sysfs_ops = &blk_mq_sysfs_ops,
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.release = blk_mq_sysfs_release,
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};
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static struct kobj_type blk_mq_ctx_ktype = {
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.sysfs_ops = &blk_mq_sysfs_ops,
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.release = blk_mq_ctx_sysfs_release,
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};
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static struct kobj_type blk_mq_hw_ktype = {
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.sysfs_ops = &blk_mq_hw_sysfs_ops,
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.default_groups = default_hw_ctx_groups,
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.release = blk_mq_hw_sysfs_release,
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};
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static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
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{
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struct blk_mq_ctx *ctx;
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int i;
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if (!hctx->nr_ctx)
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return;
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hctx_for_each_ctx(hctx, ctx, i)
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kobject_del(&ctx->kobj);
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kobject_del(&hctx->kobj);
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}
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static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
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{
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struct request_queue *q = hctx->queue;
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struct blk_mq_ctx *ctx;
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int i, ret;
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if (!hctx->nr_ctx)
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return 0;
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ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
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if (ret)
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return ret;
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hctx_for_each_ctx(hctx, ctx, i) {
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ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
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if (ret)
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break;
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}
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return ret;
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}
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void blk_mq_unregister_dev(struct device *dev, 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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lockdep_assert_held(&q->sysfs_dir_lock);
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queue_for_each_hw_ctx(q, hctx, i)
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blk_mq_unregister_hctx(hctx);
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kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
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kobject_del(q->mq_kobj);
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kobject_put(&dev->kobj);
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q->mq_sysfs_init_done = false;
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}
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void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
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{
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kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
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}
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void blk_mq_sysfs_deinit(struct request_queue *q)
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{
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struct blk_mq_ctx *ctx;
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int cpu;
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for_each_possible_cpu(cpu) {
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ctx = per_cpu_ptr(q->queue_ctx, cpu);
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kobject_put(&ctx->kobj);
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}
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kobject_put(q->mq_kobj);
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}
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void blk_mq_sysfs_init(struct request_queue *q)
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{
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struct blk_mq_ctx *ctx;
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int cpu;
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kobject_init(q->mq_kobj, &blk_mq_ktype);
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for_each_possible_cpu(cpu) {
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ctx = per_cpu_ptr(q->queue_ctx, cpu);
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kobject_get(q->mq_kobj);
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kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
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}
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}
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int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
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{
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struct blk_mq_hw_ctx *hctx;
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int ret, i;
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WARN_ON_ONCE(!q->kobj.parent);
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lockdep_assert_held(&q->sysfs_dir_lock);
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ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
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if (ret < 0)
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goto out;
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kobject_uevent(q->mq_kobj, KOBJ_ADD);
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queue_for_each_hw_ctx(q, hctx, i) {
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ret = blk_mq_register_hctx(hctx);
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if (ret)
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goto unreg;
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}
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q->mq_sysfs_init_done = true;
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out:
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return ret;
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unreg:
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while (--i >= 0)
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blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
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kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
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kobject_del(q->mq_kobj);
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kobject_put(&dev->kobj);
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return ret;
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}
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void blk_mq_sysfs_unregister(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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mutex_lock(&q->sysfs_dir_lock);
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if (!q->mq_sysfs_init_done)
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goto unlock;
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queue_for_each_hw_ctx(q, hctx, i)
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blk_mq_unregister_hctx(hctx);
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unlock:
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mutex_unlock(&q->sysfs_dir_lock);
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}
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int blk_mq_sysfs_register(struct request_queue *q)
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{
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struct blk_mq_hw_ctx *hctx;
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int i, ret = 0;
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mutex_lock(&q->sysfs_dir_lock);
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if (!q->mq_sysfs_init_done)
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goto unlock;
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queue_for_each_hw_ctx(q, hctx, i) {
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ret = blk_mq_register_hctx(hctx);
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if (ret)
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break;
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}
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unlock:
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mutex_unlock(&q->sysfs_dir_lock);
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return ret;
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}
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