From 13f35a2c0fd5c6a4fcd8903542b053bcc914fcf5 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sun, 23 Aug 2020 20:33:10 +0300 Subject: [PATCH] io-wq: fix hang after cancelling pending hashed work commit 204361a77f4018627addd4a06877448f088ddfc0 upstream. Don't forget to update wqe->hash_tail after cancelling a pending work item, if it was hashed. Cc: stable@vger.kernel.org # 5.7+ Reported-by: Dmitry Shulyak Fixes: 86f3cd1b589a1 ("io-wq: handle hashed writes in chains") Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io-wq.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/io-wq.c b/fs/io-wq.c index 47c5f3aeb4600..cb9e5a444fba7 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -929,6 +929,24 @@ static bool io_wq_worker_cancel(struct io_worker *worker, void *data) return match->nr_running && !match->cancel_all; } +static inline void io_wqe_remove_pending(struct io_wqe *wqe, + struct io_wq_work *work, + struct io_wq_work_node *prev) +{ + unsigned int hash = io_get_work_hash(work); + struct io_wq_work *prev_work = NULL; + + if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) { + if (prev) + prev_work = container_of(prev, struct io_wq_work, list); + if (prev_work && io_get_work_hash(prev_work) == hash) + wqe->hash_tail[hash] = prev_work; + else + wqe->hash_tail[hash] = NULL; + } + wq_list_del(&wqe->work_list, &work->list, prev); +} + static void io_wqe_cancel_pending_work(struct io_wqe *wqe, struct io_cb_cancel_data *match) { @@ -942,8 +960,7 @@ static void io_wqe_cancel_pending_work(struct io_wqe *wqe, work = container_of(node, struct io_wq_work, list); if (!match->fn(work, match->data)) continue; - - wq_list_del(&wqe->work_list, node, prev); + io_wqe_remove_pending(wqe, work, prev); spin_unlock_irqrestore(&wqe->lock, flags); io_run_cancel(work, wqe); match->nr_pending++;