[RFC net-next v3 22/29] io_uring: account locked pages for non-fixed zc

From: Pavel Begunkov
Date: Tue Jun 28 2022 - 15:04:16 EST


Fixed buffers are RLIMIT_MEMLOCK accounted, however it doesn't cover iovec
based zerocopy sends. Do the accounting on the io_uring side.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4a1a1d43e9b3..838030477456 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2825,7 +2825,13 @@ static void __io_notif_complete_tw(struct callback_head *cb)
{
struct io_notif *notif = container_of(cb, struct io_notif, task_work);
struct io_ring_ctx *ctx = notif->ctx;
+ struct mmpin *mmp = &notif->uarg.mmp;

+ if (unlikely(mmp->user)) {
+ atomic_long_sub(mmp->num_pg, &mmp->user->locked_vm);
+ free_uid(mmp->user);
+ mmp->user = NULL;
+ }
if (likely(notif->task)) {
io_put_task(notif->task, 1);
notif->task = NULL;
@@ -6616,6 +6622,7 @@ static int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
ret = import_single_range(WRITE, zc->buf, zc->len, &iov, &msg.msg_iter);
if (unlikely(ret))
return ret;
+ mm_account_pinned_pages(&notif->uarg.mmp, zc->len);

msg_flags = zc->msg_flags | MSG_ZEROCOPY;
if (issue_flags & IO_URING_F_NONBLOCK)
--
2.36.1