From: Dylan Yudaken dylany@fb.com
commit 09007af2b627f0f195c6c53c4829b285cc3990ec upstream.
io_import_iovec uses the s pointer, but this was changed immediately after the iovec was re-imported and so it was imported into the wrong place.
Change the ordering.
Fixes: 2be2eb02e2f5 ("io_uring: ensure reads re-import for selected buffers") Signed-off-by: Dylan Yudaken dylany@fb.com Link: https://lore.kernel.org/r/20220630132006.2825668-1-dylany@fb.com [axboe: ensure we don't half-import as well] Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/io_uring.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3495,6 +3495,13 @@ static ssize_t io_iov_buffer_select(stru return __io_iov_buffer_select(req, iov, issue_flags); }
+static inline bool io_do_buffer_select(struct io_kiocb *req) +{ + if (!(req->flags & REQ_F_BUFFER_SELECT)) + return false; + return !(req->flags & REQ_F_BUFFER_SELECTED); +} + static struct iovec *__io_import_iovec(int rw, struct io_kiocb *req, struct io_rw_state *s, unsigned int issue_flags) @@ -3854,18 +3861,19 @@ static int io_read(struct io_kiocb *req, if (unlikely(ret < 0)) return ret; } else { + rw = req->async_data; + s = &rw->s; + /* * Safe and required to re-import if we're using provided * buffers, as we dropped the selected one before retry. */ - if (req->flags & REQ_F_BUFFER_SELECT) { + if (io_do_buffer_select(req)) { ret = io_import_iovec(READ, req, &iovec, s, issue_flags); if (unlikely(ret < 0)) return ret; }
- rw = req->async_data; - s = &rw->s; /* * We come here from an earlier attempt, restore our state to * match in case it doesn't. It's cheap enough that we don't