if (!wake_page_match(wpq, key))
return 0;
+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
list_del_init(&wait->entry);
init_task_work(&req->task_work, io_req_task_submit);
wait->wait.flags = 0;
INIT_LIST_HEAD(&wait->wait.entry);
kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
kiocb->ki_waitq = wait;
io_get_req_task(req);
if (mask && !(mask & poll->events))
return 0;
+ list_del_init(&wait->entry);
+
if (poll && poll->head) {
bool done;
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
{
+ bool has_lock;
int i;
- mutex_lock(&ctx->uring_lock);
+ /*
+ * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
+ * since fdinfo case grabs it in the opposite direction of normal use
+ * cases. If we fail to get the lock, we just don't iterate any
+ * structures that could be going away outside the io_uring mutex.
+ */
+ has_lock = mutex_trylock(&ctx->uring_lock);
+
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
- for (i = 0; i < ctx->nr_user_files; i++) {
+ for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
struct fixed_file_table *table;
struct file *f;
seq_printf(m, "%5u: <none>\n", i);
}
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
- for (i = 0; i < ctx->nr_user_bufs; i++) {
+ for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
(unsigned int) buf->len);
}
- if (!idr_is_empty(&ctx->personality_idr)) {
+ if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
seq_printf(m, "Personalities:\n");
idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
}
req->task->task_works != NULL);
}
spin_unlock_irq(&ctx->completion_lock);
- mutex_unlock(&ctx->uring_lock);
+ if (has_lock)
+ mutex_unlock(&ctx->uring_lock);
}
static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)