hi,
Every close(io_uring) causes cancellation of all inflight requests
carrying ->files. That's not nice but was neccessary up until recently.
Now task->files removal is handled in the core code, so that part of
flush can be removed.
I don't catch up with newest io_uring codes yet, but have one question about
the initial implementation "io_uring: io_uring: add support for async work
inheriting files": https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fcb323cc53e29d9cc696d606bb42736b32dd9825
There was such comments:
+static int io_grab_files(struct io_ring_ctx *ctx, struct io_kiocb *req)
+{
+ int ret = -EBADF;
+
+ rcu_read_lock();
+ spin_lock_irq(&ctx->inflight_lock);
+ /*
+ * We use the f_ops->flush() handler to ensure that we can flush
+ * out work accessing these files if the fd is closed. Check if
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I wonder why we only need to flush reqs specifically when they access current->files, are there
any special reasons?
Regards,
Xiaoguang Wang
+ * the fd has changed since we started down this path, and disallow
+ * this operation if it has.
+ */
+ if (fcheck(req->submit.ring_fd) == req->submit.ring_file) {
+ list_add(&req->inflight_entry, &ctx->inflight_list);
+ req->flags |= REQ_F_INFLIGHT;
+ req->work.files = current->files;
+ ret = 0;
+ }
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 95d2bb7069c6..6536e24eb44e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8748,16 +8748,12 @@ void __io_uring_task_cancel(void)
static int io_uring_flush(struct file *file, void *data)
{
- struct io_ring_ctx *ctx = file->private_data;
+ bool exiting = !data;
- /*
- * If the task is going away, cancel work it may have pending
- */
if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
- data = NULL;
+ exiting = true;
- io_uring_cancel_task_requests(ctx, data);
- io_uring_attempt_task_drop(file, !data);
+ io_uring_attempt_task_drop(file, exiting);
return 0;
}
