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// SPDX-License-Identifier: GPL-2.0
#include <linux/net.h>
#include <linux/uio.h>
#include <net/sock.h>
#include <linux/nospec.h>
#include "rsrc.h"
#define IO_NOTIF_SPLICE_BATCH 32
#define IORING_MAX_NOTIF_SLOTS (1U << 10)
struct io_notif {
struct ubuf_info uarg;
struct io_ring_ctx *ctx;
struct io_rsrc_node *rsrc_node;
/* complete via tw if ->task is non-NULL, fallback to wq otherwise */
struct task_struct *task;
/* cqe->user_data, io_notif_slot::tag if not overridden */
u64 tag;
/* see struct io_notif_slot::seq */
u32 seq;
/* hook into ctx->notif_list and ctx->notif_list_locked */
struct list_head cache_node;
unsigned long account_pages;
union {
struct callback_head task_work;
struct work_struct commit_work;
};
};
struct io_notif_slot {
/*
* Current/active notifier. A slot holds only one active notifier at a
* time and keeps one reference to it. Flush releases the reference and
* lazily replaces it with a new notifier.
*/
struct io_notif *notif;
/*
* Default ->user_data for this slot notifiers CQEs
*/
u64 tag;
/*
* Notifiers of a slot live in generations, we create a new notifier
* only after flushing the previous one. Track the sequential number
* for all notifiers and copy it into notifiers's cqe->cflags
*/
u32 seq;
};
int io_notif_register(struct io_ring_ctx *ctx,
void __user *arg, unsigned int size);
int io_notif_unregister(struct io_ring_ctx *ctx);
void io_notif_cache_purge(struct io_ring_ctx *ctx);
void io_notif_slot_flush(struct io_notif_slot *slot);
struct io_notif *io_alloc_notif(struct io_ring_ctx *ctx,
struct io_notif_slot *slot);
static inline struct io_notif *io_get_notif(struct io_ring_ctx *ctx,
struct io_notif_slot *slot)
{
if (!slot->notif)
slot->notif = io_alloc_notif(ctx, slot);
return slot->notif;
}
static inline struct io_notif_slot *io_get_notif_slot(struct io_ring_ctx *ctx,
unsigned idx)
__must_hold(&ctx->uring_lock)
{
if (idx >= ctx->nr_notif_slots)
return NULL;
idx = array_index_nospec(idx, ctx->nr_notif_slots);
return &ctx->notif_slots[idx];
}
static inline void io_notif_slot_flush_submit(struct io_notif_slot *slot,
unsigned int issue_flags)
{
if (!(issue_flags & IO_URING_F_UNLOCKED)) {
slot->notif->task = current;
io_get_task_refs(1);
}
io_notif_slot_flush(slot);
}
static inline int io_notif_account_mem(struct io_notif *notif, unsigned len)
{
struct io_ring_ctx *ctx = notif->ctx;
unsigned nr_pages = (len >> PAGE_SHIFT) + 2;
int ret;
if (ctx->user) {
ret = __io_account_mem(ctx->user, nr_pages);
if (ret)
return ret;
notif->account_pages += nr_pages;
}
return 0;
}
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