From 252917c30f551e8e4377faac81d7fcf8e9629df1 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 13 Jul 2020 22:59:20 +0300 Subject: [PATCH] io_uring: follow **iovec idiom in io_import_iovec As for import_iovec(), return !=NULL iovec from io_import_iovec() only when it should be freed. That includes returning NULL when iovec is already in req->io, because it should be deallocated by other means, e.g. inside op handler. After io_setup_async_rw() local iovec to ->io, just mark it NULL, to follow the idea in io_{read,write} as well. That's easier to follow, and especially useful if we want to reuse per-op space for completion data. Signed-off-by: Pavel Begunkov [axboe: only call kfree() on non-NULL pointer] Signed-off-by: Jens Axboe --- fs/io_uring.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 31466bcd833e..64ae5b681c62 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2740,10 +2740,8 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req, if (req->io) { struct io_async_rw *iorw = &req->io->rw; - *iovec = iorw->iov; - iov_iter_init(iter, rw, *iovec, iorw->nr_segs, iorw->size); - if (iorw->iov == iorw->fast_iov) - *iovec = NULL; + iov_iter_init(iter, rw, iorw->iov, iorw->nr_segs, iorw->size); + *iovec = NULL; return iorw->size; } @@ -3026,6 +3024,8 @@ copy_iov: inline_vecs, &iter); if (ret) goto out_free; + /* it's copied and will be cleaned with ->io */ + iovec = NULL; /* if we can retry, do so with the callbacks armed */ if (io_rw_should_retry(req)) { ret2 = io_iter_do_read(req, &iter); @@ -3041,7 +3041,7 @@ copy_iov: } } out_free: - if (!(req->flags & REQ_F_NEED_CLEANUP)) + if (iovec) kfree(iovec); return ret; } @@ -3143,11 +3143,13 @@ copy_iov: inline_vecs, &iter); if (ret) goto out_free; + /* it's copied and will be cleaned with ->io */ + iovec = NULL; return -EAGAIN; } } out_free: - if (!(req->flags & REQ_F_NEED_CLEANUP)) + if (iovec) kfree(iovec); return ret; }