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#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/io_uring.h>
#include "io_uring.h"
#include "notif.h"
#include "rsrc.h"
static void __io_notif_complete_tw(struct io_kiocb *notif, bool *locked)
{
struct io_notif_data *nd = io_notif_to_data(notif);
struct io_ring_ctx *ctx = notif->ctx;
if (nd->account_pages && ctx->user) {
__io_unaccount_mem(ctx->user, nd->account_pages);
nd->account_pages = 0;
}
io_req_task_complete(notif, locked);
}
static inline void io_notif_complete(struct io_kiocb *notif)
__must_hold(¬if->ctx->uring_lock)
{
bool locked = true;
__io_notif_complete_tw(notif, &locked);
}
static void io_uring_tx_zerocopy_callback(struct sk_buff *skb,
struct ubuf_info *uarg,
bool success)
{
struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg);
struct io_kiocb *notif = cmd_to_io_kiocb(nd);
if (refcount_dec_and_test(&uarg->refcnt)) {
notif->io_task_work.func = __io_notif_complete_tw;
io_req_task_work_add(notif);
}
}
struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx,
struct io_notif_slot *slot)
__must_hold(&ctx->uring_lock)
{
struct io_kiocb *notif;
struct io_notif_data *nd;
if (unlikely(!io_alloc_req_refill(ctx)))
return NULL;
notif = io_alloc_req(ctx);
notif->opcode = IORING_OP_NOP;
notif->flags = 0;
notif->file = NULL;
notif->task = current;
io_get_task_refs(1);
notif->rsrc_node = NULL;
io_req_set_rsrc_node(notif, ctx, 0);
notif->cqe.user_data = slot->tag;
notif->cqe.flags = slot->seq++;
notif->cqe.res = 0;
nd = io_notif_to_data(notif);
nd->account_pages = 0;
nd->uarg.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
nd->uarg.callback = io_uring_tx_zerocopy_callback;
/* master ref owned by io_notif_slot, will be dropped on flush */
refcount_set(&nd->uarg.refcnt, 1);
return notif;
}
void io_notif_slot_flush(struct io_notif_slot *slot)
__must_hold(&ctx->uring_lock)
{
struct io_kiocb *notif = slot->notif;
struct io_notif_data *nd = io_notif_to_data(notif);
slot->notif = NULL;
/* drop slot's master ref */
if (refcount_dec_and_test(&nd->uarg.refcnt))
io_notif_complete(notif);
}
__cold int io_notif_unregister(struct io_ring_ctx *ctx)
__must_hold(&ctx->uring_lock)
{
int i;
if (!ctx->notif_slots)
return -ENXIO;
for (i = 0; i < ctx->nr_notif_slots; i++) {
struct io_notif_slot *slot = &ctx->notif_slots[i];
struct io_kiocb *notif = slot->notif;
struct io_notif_data *nd;
if (!notif)
continue;
nd = io_kiocb_to_cmd(notif);
slot->notif = NULL;
if (!refcount_dec_and_test(&nd->uarg.refcnt))
continue;
notif->io_task_work.func = __io_notif_complete_tw;
io_req_task_work_add(notif);
}
kvfree(ctx->notif_slots);
ctx->notif_slots = NULL;
ctx->nr_notif_slots = 0;
return 0;
}
__cold int io_notif_register(struct io_ring_ctx *ctx,
void __user *arg, unsigned int size)
__must_hold(&ctx->uring_lock)
{
struct io_uring_notification_slot __user *slots;
struct io_uring_notification_slot slot;
struct io_uring_notification_register reg;
unsigned i;
BUILD_BUG_ON(sizeof(struct io_notif_data) > 64);
if (ctx->nr_notif_slots)
return -EBUSY;
if (size != sizeof(reg))
return -EINVAL;
if (copy_from_user(®, arg, sizeof(reg)))
return -EFAULT;
if (!reg.nr_slots || reg.nr_slots > IORING_MAX_NOTIF_SLOTS)
return -EINVAL;
if (reg.resv || reg.resv2 || reg.resv3)
return -EINVAL;
slots = u64_to_user_ptr(reg.data);
ctx->notif_slots = kvcalloc(reg.nr_slots, sizeof(ctx->notif_slots[0]),
GFP_KERNEL_ACCOUNT);
if (!ctx->notif_slots)
return -ENOMEM;
for (i = 0; i < reg.nr_slots; i++, ctx->nr_notif_slots++) {
struct io_notif_slot *notif_slot = &ctx->notif_slots[i];
if (copy_from_user(&slot, &slots[i], sizeof(slot))) {
io_notif_unregister(ctx);
return -EFAULT;
}
if (slot.resv[0] | slot.resv[1] | slot.resv[2]) {
io_notif_unregister(ctx);
return -EINVAL;
}
notif_slot->tag = slot.tag;
}
return 0;
}
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