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authorJens Axboe <axboe@kernel.dk>2019-12-17 18:40:57 -0700
committerJens Axboe <axboe@kernel.dk>2019-12-17 19:57:27 -0700
commit0969e783e3a8913f79df27286501a6c21e961524 (patch)
treeb8c6153da9052d629dbc47fa127f8af6d8223ce5 /fs
parentffbb8d6b76910d4f3a2bafeaf68c419011e98d05 (diff)
io_uring: make IORING_POLL_ADD and IORING_POLL_REMOVE deferrable
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/io_uring.c68
1 files changed, 54 insertions, 14 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index b476bd304045..b0411406c50a 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;
@@ -2490,24 +2493,40 @@ 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);
@@ -2642,16 +2661,14 @@ 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)
@@ -2659,9 +2676,26 @@ 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;
@@ -3029,6 +3063,12 @@ 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;