This is a note to let you know that I've just added the patch titled io_uring: add flag for disabling provided buffer recycling to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-add-flag-for-disabling-provided-buffer-recy.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit eb53b52ebcf3811844dfa6718842c85d9bbe1401 Author: Jens Axboe <axboe@xxxxxxxxx> Date: Wed Mar 23 09:30:05 2022 -0600 io_uring: add flag for disabling provided buffer recycling commit 8a3e8ee56417f5e0e66580d93941ed9d6f4c8274 upstream. If we need to continue doing this IO, then we don't want a potentially selected buffer recycled. Add a flag for that. Set this for recv/recvmsg if they do partial IO. Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 3d67b9b4100f..7f9fb0cb9230 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -740,6 +740,7 @@ enum { REQ_F_CREDS_BIT, REQ_F_REFCOUNT_BIT, REQ_F_ARM_LTIMEOUT_BIT, + REQ_F_PARTIAL_IO_BIT, /* keep async read/write and isreg together and in order */ REQ_F_NOWAIT_READ_BIT, REQ_F_NOWAIT_WRITE_BIT, @@ -795,6 +796,8 @@ enum { REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT), /* there is a linked timeout that has to be armed */ REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT), + /* request has already done partial IO */ + REQ_F_PARTIAL_IO = BIT(REQ_F_PARTIAL_IO_BIT), }; struct async_poll { @@ -4963,6 +4966,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) ret = -EINTR; if (ret > 0 && io_net_retry(sock, flags)) { sr->done_io += ret; + req->flags |= REQ_F_PARTIAL_IO; return io_setup_async_msg(req, kmsg); } req_set_fail(req); @@ -5036,6 +5040,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) sr->len -= ret; sr->buf += ret; sr->done_io += ret; + req->flags |= REQ_F_PARTIAL_IO; return -EAGAIN; } req_set_fail(req);