Another preparation patch. When full quiesce is done on ctx exit, use
task_work infra to remove corresponding to the ctx io_uring->xa entries.
For that we use the back tctx map. Also use ->in_idle to prevent
removing it while we traversing ->xa on cancellation, just ignore it.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 46 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f26f8199e4ab..692096e85749 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -987,6 +987,7 @@ static const struct io_op_def io_op_defs[] = {
[IORING_OP_UNLINKAT] = {},
};
+static void io_uring_del_task_file(unsigned long index);
static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
struct files_struct *files);
@@ -8531,10 +8532,33 @@ static bool io_run_ctx_fallback(struct io_ring_ctx *ctx)
return executed;
}
+struct io_tctx_exit {
+ struct callback_head task_work;
+ struct completion completion;
+ unsigned long index;
+};
+
+static void io_tctx_exit_cb(struct callback_head *cb)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_exit *work;
+
+ work = container_of(cb, struct io_tctx_exit, task_work);
+ /*
+ * When @in_idle, we're in cancellation and it's racy to remove the
+ * node. It'll be removed by the end of cancellation, just ignore it.
+ */
+ if (!atomic_read(&tctx->in_idle))
+ io_uring_del_task_file(work->index);
+ complete(&work->completion);
+}
+
static void io_ring_exit_work(struct work_struct *work)
{
- struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
- exit_work);
+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
+ struct io_tctx_exit exit;
+ struct io_tctx_node *node;
+ int ret;
/*
* If we're doing polled IO and end up having requests being
@@ -8545,6 +8569,26 @@ static void io_ring_exit_work(struct work_struct *work)
do {
io_uring_try_cancel_requests(ctx, NULL, NULL);
} while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
+
+ mutex_lock(&ctx->uring_lock);
+ while (!list_empty(&ctx->tctx_list)) {
+ node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
+ ctx_node);
+ exit.index = (unsigned long)node->file;
+ init_completion(&exit.completion);
+ init_task_work(&exit.task_work, io_tctx_exit_cb);
+ ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
+ if (WARN_ON_ONCE(ret))
+ continue;
+ wake_up_process(node->task);
+
+ mutex_unlock(&ctx->uring_lock);
+ wait_for_completion(&exit.completion);
+ cond_resched();
+ mutex_lock(&ctx->uring_lock);
+ }
+ mutex_unlock(&ctx->uring_lock);
+
io_ring_ctx_free(ctx);
}
--
2.24.0
