diff options
Diffstat (limited to 'io_uring/poll.c')
| -rw-r--r-- | io_uring/poll.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/io_uring/poll.c b/io_uring/poll.c index 0d9f49c575e0..055632e9092a 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -116,6 +116,8 @@ static void io_poll_req_insert_locked(struct io_kiocb *req) struct io_hash_table *table = &req->ctx->cancel_table_locked; u32 index = hash_long(req->cqe.user_data, table->hash_bits); + lockdep_assert_held(&req->ctx->uring_lock); + hlist_add_head(&req->hash_node, &table->hbs[index].list); } @@ -226,6 +228,13 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) return IOU_POLL_DONE; if (v & IO_POLL_CANCEL_FLAG) return -ECANCELED; + /* + * cqe.res contains only events of the first wake up + * and all others are be lost. Redo vfs_poll() to get + * up to date state. + */ + if ((v & IO_POLL_REF_MASK) != 1) + req->cqe.res = 0; /* the mask was stashed in __io_poll_execute */ if (!req->cqe.res) { @@ -237,6 +246,8 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) continue; if (req->apoll_events & EPOLLONESHOT) return IOU_POLL_DONE; + if (io_is_uring_fops(req->file)) + return IOU_POLL_DONE; /* multishot, just fill a CQE and proceed */ if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { @@ -256,6 +267,9 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) return ret; } + /* force the next iteration to vfs_poll() */ + req->cqe.res = 0; + /* * Release all references, retry if someone tried to restart * task_work while we were executing it. @@ -394,7 +408,8 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, return 1; } -static void io_poll_double_prepare(struct io_kiocb *req) +/* fails only when polling is already completing by the first entry */ +static bool io_poll_double_prepare(struct io_kiocb *req) { struct wait_queue_head *head; struct io_poll *poll = io_poll_get_single(req); @@ -403,20 +418,20 @@ static void io_poll_double_prepare(struct io_kiocb *req) rcu_read_lock(); head = smp_load_acquire(&poll->head); /* - * poll arm may not hold ownership and so race with - * io_poll_wake() by modifying req->flags. There is only one - * poll entry queued, serialise with it by taking its head lock. + * poll arm might not hold ownership and so race for req->flags with + * io_poll_wake(). There is only one poll entry queued, serialise with + * it by taking its head lock. As we're still arming the tw hanlder + * is not going to be run, so there are no races with it. */ - if (head) + if (head) { spin_lock_irq(&head->lock); - - req->flags |= REQ_F_DOUBLE_POLL; - if (req->opcode == IORING_OP_POLL_ADD) - req->flags |= REQ_F_ASYNC_DATA; - - if (head) + req->flags |= REQ_F_DOUBLE_POLL; + if (req->opcode == IORING_OP_POLL_ADD) + req->flags |= REQ_F_ASYNC_DATA; spin_unlock_irq(&head->lock); + } rcu_read_unlock(); + return !!head; } static void __io_queue_proc(struct io_poll *poll, struct io_poll_table *pt, @@ -454,7 +469,11 @@ static void __io_queue_proc(struct io_poll *poll, struct io_poll_table *pt, /* mark as double wq entry */ wqe_private |= IO_WQE_F_DOUBLE; io_init_poll_iocb(poll, first->events, first->wait.func); - io_poll_double_prepare(req); + if (!io_poll_double_prepare(req)) { + /* the request is completing, just back off */ + kfree(poll); + return; + } *poll_ptr = poll; } else { /* fine to modify, there is no poll queued to race with us */ |