From: Pavel Begunkov asml.silence@gmail.com
mainline inclusion from mainline-5.9-rc4 commit b7ddce3cbf010edbfac6c6d8cc708560a7bcd7a4 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
While trying to cancel requests with ->files, it also should look for requests in ->defer_list, otherwise it might end up hanging a thread.
Cancel all requests in ->defer_list up to the last request there with matching ->files, that's needed to follow drain ordering semantics.
Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk 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 | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 7163271d14c3..36536ed5659e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7867,12 +7867,39 @@ static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) io_timeout_remove_link(ctx, req); }
+static void io_cancel_defer_files(struct io_ring_ctx *ctx, + struct files_struct *files) +{ + struct io_defer_entry *de = NULL; + LIST_HEAD(list); + + spin_lock_irq(&ctx->completion_lock); + list_for_each_entry_reverse(de, &ctx->defer_list, list) { + if ((de->req->flags & REQ_F_WORK_INITIALIZED) + && de->req->work.files == files) { + list_cut_position(&list, &ctx->defer_list, &de->list); + break; + } + } + spin_unlock_irq(&ctx->completion_lock); + + while (!list_empty(&list)) { + de = list_first_entry(&list, struct io_defer_entry, list); + list_del_init(&de->list); + req_set_fail_links(de->req); + io_put_req(de->req); + io_req_complete(de->req, -ECANCELED); + kfree(de); + } +} + static void io_uring_cancel_files(struct io_ring_ctx *ctx, struct files_struct *files) { if (list_empty_careful(&ctx->inflight_list)) return;
+ io_cancel_defer_files(ctx, files); /* cancel all at once, should be faster than doing it one by one*/ io_wq_cancel_cb(ctx->io_wq, io_wq_files_match, files, true);