From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 08/13] io_uring: make IORING_POLL_ADD and IORING_POLL_REMOVE deferrable
Date: Wed, 18 Dec 2019 10:18:30 -0700 [thread overview]
Message-ID: <20191218171835.13315-9-axboe@kernel.dk> (raw)
In-Reply-To: <20191218171835.13315-1-axboe@kernel.dk>
If we defer these commands as part of a link, we have to make sure that
the SQE data has been read upfront. Integrate the poll add/remove into
the prep handling to make it safe for SQE reuse.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 68 ++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 54 insertions(+), 14 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 12cc641eb833..aa5d6232c536 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -289,7 +289,10 @@ struct io_ring_ctx {
*/
struct io_poll_iocb {
struct file *file;
- struct wait_queue_head *head;
+ union {
+ struct wait_queue_head *head;
+ u64 addr;
+ };
__poll_t events;
bool done;
bool canceled;
@@ -2488,24 +2491,40 @@ static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
return -ENOENT;
}
+static int io_poll_remove_prep(struct io_kiocb *req)
+{
+ const struct io_uring_sqe *sqe = req->sqe;
+
+ if (req->flags & REQ_F_PREPPED)
+ return 0;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
+ sqe->poll_events)
+ return -EINVAL;
+
+ req->poll.addr = READ_ONCE(sqe->addr);
+ req->flags |= REQ_F_PREPPED;
+ return 0;
+}
+
/*
* Find a running poll command that matches one specified in sqe->addr,
* and remove it if found.
*/
static int io_poll_remove(struct io_kiocb *req)
{
- const struct io_uring_sqe *sqe = req->sqe;
struct io_ring_ctx *ctx = req->ctx;
+ u64 addr;
int ret;
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
- sqe->poll_events)
- return -EINVAL;
+ ret = io_poll_remove_prep(req);
+ if (ret)
+ return ret;
+ addr = req->poll.addr;
spin_lock_irq(&ctx->completion_lock);
- ret = io_poll_cancel(ctx, READ_ONCE(sqe->addr));
+ ret = io_poll_cancel(ctx, addr);
spin_unlock_irq(&ctx->completion_lock);
io_cqring_add_event(req, ret);
@@ -2640,16 +2659,14 @@ static void io_poll_req_insert(struct io_kiocb *req)
hlist_add_head(&req->hash_node, list);
}
-static int io_poll_add(struct io_kiocb *req, struct io_kiocb **nxt)
+static int io_poll_add_prep(struct io_kiocb *req)
{
const struct io_uring_sqe *sqe = req->sqe;
struct io_poll_iocb *poll = &req->poll;
- struct io_ring_ctx *ctx = req->ctx;
- struct io_poll_table ipt;
- bool cancel = false;
- __poll_t mask;
u16 events;
+ if (req->flags & REQ_F_PREPPED)
+ return 0;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
@@ -2657,9 +2674,26 @@ static int io_poll_add(struct io_kiocb *req, struct io_kiocb **nxt)
if (!poll->file)
return -EBADF;
- INIT_IO_WORK(&req->work, io_poll_complete_work);
+ req->flags |= REQ_F_PREPPED;
events = READ_ONCE(sqe->poll_events);
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;
+ return 0;
+}
+
+static int io_poll_add(struct io_kiocb *req, struct io_kiocb **nxt)
+{
+ struct io_poll_iocb *poll = &req->poll;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_poll_table ipt;
+ bool cancel = false;
+ __poll_t mask;
+ int ret;
+
+ ret = io_poll_add_prep(req);
+ if (ret)
+ return ret;
+
+ INIT_IO_WORK(&req->work, io_poll_complete_work);
INIT_HLIST_NODE(&req->hash_node);
poll->head = NULL;
@@ -3027,6 +3061,12 @@ static int io_req_defer_prep(struct io_kiocb *req)
io_req_map_rw(req, ret, iovec, inline_vecs, &iter);
ret = 0;
break;
+ case IORING_OP_POLL_ADD:
+ ret = io_poll_add_prep(req);
+ break;
+ case IORING_OP_POLL_REMOVE:
+ ret = io_poll_remove_prep(req);
+ break;
case IORING_OP_FSYNC:
ret = io_prep_fsync(req);
break;
--
2.24.1
next prev parent reply other threads:[~2019-12-18 17:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-18 17:18 [PATCHSET v3] io_uring fixes for 5.5-rc3 Jens Axboe
2019-12-18 17:18 ` [PATCH 01/13] io_uring: fix stale comment and a few typos Jens Axboe
2019-12-18 17:18 ` [PATCH 02/13] io_uring: fix sporadic -EFAULT from IORING_OP_RECVMSG Jens Axboe
2019-12-18 17:18 ` [PATCH 03/13] io-wq: re-add io_wq_current_is_worker() Jens Axboe
2019-12-18 17:18 ` [PATCH 04/13] io_uring: fix pre-prepped issue with force_nonblock == true Jens Axboe
2019-12-18 17:18 ` [PATCH 05/13] io_uring: remove 'sqe' parameter to the OP helpers that take it Jens Axboe
2019-12-18 17:18 ` [PATCH 06/13] io_uring: any deferred command must have stable sqe data Jens Axboe
2019-12-18 17:18 ` [PATCH 07/13] io_uring: make HARDLINK imply LINK Jens Axboe
2019-12-18 17:18 ` Jens Axboe [this message]
2019-12-18 17:18 ` [PATCH 09/13] io_uring: make IORING_OP_CANCEL_ASYNC deferrable Jens Axboe
2019-12-18 17:18 ` [PATCH 10/13] io_uring: make IORING_OP_TIMEOUT_REMOVE deferrable Jens Axboe
2019-12-18 17:18 ` [PATCH 11/13] io_uring: read opcode and user_data from SQE exactly once Jens Axboe
2019-12-18 17:18 ` [PATCH 12/13] io_uring: warn about unhandled opcode Jens Axboe
2019-12-18 17:18 ` [PATCH 13/13] io_uring: don't wait when under-submitting Jens Axboe
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