From c183edff33fdcd639d222a8f473bf44602adc655 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 4 Sep 2020 22:36:52 -0600 Subject: [PATCH] io_uring: fix explicit async read/write mapping for large segments If we exceed UIO_FASTIOV, we don't handle the transition correctly between an allocated vec for requests that are queued with IOSQE_ASYNC. Store the iovec appropriately and re-set it in the iter iov in case it changed. Fixes: ff6165b2d7f6 ("io_uring: retain iov_iter state over io_read/io_write calls") Reported-by: Nick Hill Tested-by: Norman Maurer Signed-off-by: Jens Axboe --- fs/io_uring.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 64c5a52fad126..f703182df2d4d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2980,14 +2980,15 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw, bool force_nonblock) { struct io_async_rw *iorw = &req->io->rw; + struct iovec *iov; ssize_t ret; - iorw->iter.iov = iorw->fast_iov; - ret = __io_import_iovec(rw, req, (struct iovec **) &iorw->iter.iov, - &iorw->iter, !force_nonblock); + iorw->iter.iov = iov = iorw->fast_iov; + ret = __io_import_iovec(rw, req, &iov, &iorw->iter, !force_nonblock); if (unlikely(ret < 0)) return ret; + iorw->iter.iov = iov; io_req_map_rw(req, iorw->iter.iov, iorw->fast_iov, &iorw->iter); return 0; } -- 2.50.1