linux/io_uring/notif.h
Stefan Metzmacher e307e66981 io_uring/net: introduce IORING_SEND_ZC_REPORT_USAGE flag
It might be useful for applications to detect if a zero copy transfer with
SEND[MSG]_ZC was actually possible or not. The application can fallback to
plain SEND[MSG] in order to avoid the overhead of two cqes per request. Or
it can generate a log message that could indicate to an administrator that
no zero copy was possible and could explain degraded performance.

Cc: stable@vger.kernel.org # 6.1
Link: https://lore.kernel.org/io-uring/fb6a7599-8a9b-15e5-9b64-6cd9d01c6ff4@gmail.com/T/#m2b0d9df94ce43b0e69e6c089bdff0ce6babbdfaa
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8945b01756d902f5d5b0667f20b957ad3f742e5e.1666895626.git.metze@samba.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-21 07:38:31 -07:00

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C

// 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
struct io_notif_data {
struct file *file;
struct ubuf_info uarg;
unsigned long account_pages;
bool zc_report;
bool zc_used;
bool zc_copied;
};
void io_notif_flush(struct io_kiocb *notif);
struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx);
static inline struct io_notif_data *io_notif_to_data(struct io_kiocb *notif)
{
return io_kiocb_to_cmd(notif, struct io_notif_data);
}
static inline int io_notif_account_mem(struct io_kiocb *notif, unsigned len)
{
struct io_ring_ctx *ctx = notif->ctx;
struct io_notif_data *nd = io_notif_to_data(notif);
unsigned nr_pages = (len >> PAGE_SHIFT) + 2;
int ret;
if (ctx->user) {
ret = __io_account_mem(ctx->user, nr_pages);
if (ret)
return ret;
nd->account_pages += nr_pages;
}
return 0;
}