From: Pavel Begunkov asml.silence@gmail.com
mainline inclusion from mainline-5.5-rc1 commit f9bd67f69af56d712bfd498f5ad9cf7bb177d600 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
Pass only non-null @nxt to io_issue_sqe() and handle it at the caller's side. And propagate it.
- kiocb_done() is only called from io_read() and io_write(), which are only called from io_issue_sqe(), so it's @nxt != NULL
- io_put_req_find_next() is called either with explicitly non-null local nxt, or from one of the functions in io_issue_sqe() switch (or their callees).
Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/io_uring.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index cd04220944b3..f73f2d9a5c56 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -989,21 +989,13 @@ static void io_free_req(struct io_kiocb *req) * Drop reference to request, return next in chain (if there is one) if this * was the last reference to this request. */ +__attribute__((nonnull)) static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr) { - struct io_kiocb *nxt = NULL; - - io_req_find_next(req, &nxt); + io_req_find_next(req, nxtptr);
if (refcount_dec_and_test(&req->refs)) __io_free_req(req); - - if (nxt) { - if (nxtptr) - *nxtptr = nxt; - else - io_queue_async_work(nxt); - } }
static void io_put_req(struct io_kiocb *req) @@ -1487,7 +1479,7 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt, bool in_async) { - if (in_async && ret >= 0 && nxt && kiocb->ki_complete == io_complete_rw) + if (in_async && ret >= 0 && kiocb->ki_complete == io_complete_rw) *nxt = __io_complete_rw(kiocb, ret); else io_rw_done(kiocb, ret); @@ -2584,6 +2576,7 @@ static int io_req_defer(struct io_kiocb *req) return -EIOCBQUEUED; }
+__attribute__((nonnull)) static int io_issue_sqe(struct io_kiocb *req, struct io_kiocb **nxt, bool force_nonblock) { @@ -2900,10 +2893,13 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
static void __io_queue_sqe(struct io_kiocb *req) { - struct io_kiocb *nxt = io_prep_linked_timeout(req); + struct io_kiocb *linked_timeout = io_prep_linked_timeout(req); + struct io_kiocb *nxt = NULL; int ret;
- ret = io_issue_sqe(req, NULL, true); + ret = io_issue_sqe(req, &nxt, true); + if (nxt) + io_queue_async_work(nxt);
/* * We async punt it if the file wasn't marked NOWAIT, or if the file @@ -2939,11 +2935,11 @@ static void __io_queue_sqe(struct io_kiocb *req) /* drop submission reference */ io_put_req(req);
- if (nxt) { + if (linked_timeout) { if (!ret) - io_queue_linked_timeout(nxt); + io_queue_linked_timeout(linked_timeout); else - io_put_req(nxt); + io_put_req(linked_timeout); }
/* and drop final reference, if we failed */