diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 148 |
1 files changed, 1 insertions, 147 deletions
@@ -5,7 +5,6 @@ * Implements an efficient asynchronous io interface. * * Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved. - * Copyright 2018 Christoph Hellwig. * * See ../COPYING for licensing terms. */ @@ -165,22 +164,10 @@ struct fsync_iocb { bool datasync; }; -struct poll_iocb { - struct file *file; - __poll_t events; - struct wait_queue_head *head; - - union { - struct wait_queue_entry wait; - struct work_struct work; - }; -}; - struct aio_kiocb { union { struct kiocb rw; struct fsync_iocb fsync; - struct poll_iocb poll; }; struct kioctx *ki_ctx; @@ -1590,6 +1577,7 @@ static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync) if (unlikely(iocb->aio_buf || iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags)) return -EINVAL; + req->file = fget(iocb->aio_fildes); if (unlikely(!req->file)) return -EBADF; @@ -1604,137 +1592,6 @@ static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync) return 0; } -/* need to use list_del_init so we can check if item was present */ -static inline bool __aio_poll_remove(struct poll_iocb *req) -{ - if (list_empty(&req->wait.entry)) - return false; - list_del_init(&req->wait.entry); - return true; -} - -static inline void __aio_poll_complete(struct aio_kiocb *iocb, __poll_t mask) -{ - fput(iocb->poll.file); - aio_complete(iocb, mangle_poll(mask), 0); -} - -static void aio_poll_work(struct work_struct *work) -{ - struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, poll.work); - - if (!list_empty_careful(&iocb->ki_list)) - aio_remove_iocb(iocb); - __aio_poll_complete(iocb, iocb->poll.events); -} - -static int aio_poll_cancel(struct kiocb *iocb) -{ - struct aio_kiocb *aiocb = container_of(iocb, struct aio_kiocb, rw); - struct poll_iocb *req = &aiocb->poll; - struct wait_queue_head *head = req->head; - bool found = false; - - spin_lock(&head->lock); - found = __aio_poll_remove(req); - spin_unlock(&head->lock); - - if (found) { - req->events = 0; - INIT_WORK(&req->work, aio_poll_work); - schedule_work(&req->work); - } - return 0; -} - -static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, - void *key) -{ - struct poll_iocb *req = container_of(wait, struct poll_iocb, wait); - struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll); - struct file *file = req->file; - __poll_t mask = key_to_poll(key); - - assert_spin_locked(&req->head->lock); - - /* for instances that support it check for an event match first: */ - if (mask && !(mask & req->events)) - return 0; - - mask = file->f_op->poll_mask(file, req->events) & req->events; - if (!mask) - return 0; - - __aio_poll_remove(req); - - /* - * Try completing without a context switch if we can acquire ctx_lock - * without spinning. Otherwise we need to defer to a workqueue to - * avoid a deadlock due to the lock order. - */ - if (spin_trylock(&iocb->ki_ctx->ctx_lock)) { - list_del_init(&iocb->ki_list); - spin_unlock(&iocb->ki_ctx->ctx_lock); - - __aio_poll_complete(iocb, mask); - } else { - req->events = mask; - INIT_WORK(&req->work, aio_poll_work); - schedule_work(&req->work); - } - - return 1; -} - -static ssize_t aio_poll(struct aio_kiocb *aiocb, struct iocb *iocb) -{ - struct kioctx *ctx = aiocb->ki_ctx; - struct poll_iocb *req = &aiocb->poll; - __poll_t mask; - - /* reject any unknown events outside the normal event mask. */ - if ((u16)iocb->aio_buf != iocb->aio_buf) - return -EINVAL; - /* reject fields that are not defined for poll */ - if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags) - return -EINVAL; - - req->events = demangle_poll(iocb->aio_buf) | EPOLLERR | EPOLLHUP; - req->file = fget(iocb->aio_fildes); - if (unlikely(!req->file)) - return -EBADF; - if (!file_has_poll_mask(req->file)) - goto out_fail; - - req->head = req->file->f_op->get_poll_head(req->file, req->events); - if (!req->head) - goto out_fail; - if (IS_ERR(req->head)) { - mask = EPOLLERR; - goto done; - } - - init_waitqueue_func_entry(&req->wait, aio_poll_wake); - aiocb->ki_cancel = aio_poll_cancel; - - spin_lock_irq(&ctx->ctx_lock); - spin_lock(&req->head->lock); - mask = req->file->f_op->poll_mask(req->file, req->events) & req->events; - if (!mask) { - __add_wait_queue(req->head, &req->wait); - list_add_tail(&aiocb->ki_list, &ctx->active_reqs); - } - spin_unlock(&req->head->lock); - spin_unlock_irq(&ctx->ctx_lock); -done: - if (mask) - __aio_poll_complete(aiocb, mask); - return 0; -out_fail: - fput(req->file); - return -EINVAL; /* same as no support for IOCB_CMD_POLL */ -} - static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, bool compat) { @@ -1808,9 +1665,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, case IOCB_CMD_FDSYNC: ret = aio_fsync(&req->fsync, &iocb, true); break; - case IOCB_CMD_POLL: - ret = aio_poll(req, &iocb); - break; default: pr_debug("invalid aio operation %d\n", iocb.aio_lio_opcode); ret = -EINVAL; |