This is a note to let you know that I've just added the patch titled io_uring: wrap io_kiocb reference count manipulation in helpers to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-wrap-io_kiocb-reference-count-manipulation-.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d1f49ca3b4dbda15e114a8946bf809b8020ee0bc Author: Jens Axboe <axboe@xxxxxxxxx> Date: Wed Feb 24 13:28:27 2021 -0700 io_uring: wrap io_kiocb reference count manipulation in helpers [ Upstream commit de9b4ccad750f216616730b74ed2be16c80892a4 ] No functional changes in this patch, just in preparation for handling the references a bit more efficiently. Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/io_uring.c b/fs/io_uring.c index 5cc76fa9d4a1..dd8b3fac877c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1476,6 +1476,31 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, return ret; } +static inline bool req_ref_inc_not_zero(struct io_kiocb *req) +{ + return refcount_inc_not_zero(&req->refs); +} + +static inline bool req_ref_sub_and_test(struct io_kiocb *req, int refs) +{ + return refcount_sub_and_test(refs, &req->refs); +} + +static inline bool req_ref_put_and_test(struct io_kiocb *req) +{ + return refcount_dec_and_test(&req->refs); +} + +static inline void req_ref_put(struct io_kiocb *req) +{ + refcount_dec(&req->refs); +} + +static inline void req_ref_get(struct io_kiocb *req) +{ + refcount_inc(&req->refs); +} + static void __io_cqring_fill_event(struct io_kiocb *req, long res, unsigned int cflags) { @@ -1512,7 +1537,7 @@ static void __io_cqring_fill_event(struct io_kiocb *req, long res, io_clean_op(req); req->result = res; req->compl.cflags = cflags; - refcount_inc(&req->refs); + req_ref_get(req); list_add_tail(&req->compl.list, &ctx->cq_overflow_list); } } @@ -1534,7 +1559,7 @@ static void io_req_complete_post(struct io_kiocb *req, long res, * If we're the last reference to this request, add to our locked * free_list cache. */ - if (refcount_dec_and_test(&req->refs)) { + if (req_ref_put_and_test(req)) { struct io_comp_state *cs = &ctx->submit_state.comp; if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { @@ -2113,7 +2138,7 @@ static void io_submit_flush_completions(struct io_comp_state *cs, req = cs->reqs[i]; /* submission and completion refs */ - if (refcount_sub_and_test(2, &req->refs)) + if (req_ref_sub_and_test(req, 2)) io_req_free_batch(&rb, req, &ctx->submit_state); } @@ -2129,7 +2154,7 @@ static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) { struct io_kiocb *nxt = NULL; - if (refcount_dec_and_test(&req->refs)) { + if (req_ref_put_and_test(req)) { nxt = io_req_find_next(req); __io_free_req(req); } @@ -2138,7 +2163,7 @@ static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) static void io_put_req(struct io_kiocb *req) { - if (refcount_dec_and_test(&req->refs)) + if (req_ref_put_and_test(req)) io_free_req(req); } @@ -2161,14 +2186,14 @@ static void io_free_req_deferred(struct io_kiocb *req) static inline void io_put_req_deferred(struct io_kiocb *req, int refs) { - if (refcount_sub_and_test(refs, &req->refs)) + if (req_ref_sub_and_test(req, refs)) io_free_req_deferred(req); } static void io_double_put_req(struct io_kiocb *req) { /* drop both submit and complete references */ - if (refcount_sub_and_test(2, &req->refs)) + if (req_ref_sub_and_test(req, 2)) io_free_req(req); } @@ -2254,7 +2279,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, __io_cqring_fill_event(req, req->result, cflags); (*nr_events)++; - if (refcount_dec_and_test(&req->refs)) + if (req_ref_put_and_test(req)) io_req_free_batch(&rb, req, &ctx->submit_state); } @@ -2496,7 +2521,7 @@ static bool io_rw_reissue(struct io_kiocb *req) lockdep_assert_held(&req->ctx->uring_lock); if (io_resubmit_prep(req)) { - refcount_inc(&req->refs); + req_ref_get(req); io_queue_async_work(req); return true; } @@ -3209,7 +3234,7 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, list_del_init(&wait->entry); /* submit ref gets dropped, acquire a new one */ - refcount_inc(&req->refs); + req_ref_get(req); io_req_task_queue(req); return 1; } @@ -4954,7 +4979,7 @@ static void io_poll_remove_double(struct io_kiocb *req) spin_lock(&head->lock); list_del_init(&poll->wait.entry); if (poll->wait.private) - refcount_dec(&req->refs); + req_ref_put(req); poll->head = NULL; spin_unlock(&head->lock); } @@ -5020,7 +5045,7 @@ static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode, poll->wait.func(&poll->wait, mode, sync, key); } } - refcount_dec(&req->refs); + req_ref_put(req); return 1; } @@ -5063,7 +5088,7 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, return; } io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake); - refcount_inc(&req->refs); + req_ref_get(req); poll->wait.private = req; *poll_ptr = poll; } @@ -6212,7 +6237,7 @@ static void io_wq_submit_work(struct io_wq_work *work) /* avoid locking problems by failing it from a clean context */ if (ret) { /* io-wq is going to take one down */ - refcount_inc(&req->refs); + req_ref_get(req); io_req_task_queue_fail(req, ret); } } @@ -6264,7 +6289,7 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) * We don't expect the list to be empty, that will only happen if we * race with the completion of the linked work. */ - if (prev && refcount_inc_not_zero(&prev->refs)) + if (prev && req_ref_inc_not_zero(prev)) io_remove_next_linked(prev); else prev = NULL;