io_uring: order refnode recycling

Don't recycle a refnode until we're done with all requests of nodes
ejected before.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-11-18 14:56:26 +00:00 committed by Jens Axboe
parent 1e5d770bb8
commit e297822b20

View File

@ -205,6 +205,7 @@ struct fixed_file_ref_node {
struct list_head file_list;
struct fixed_file_data *file_data;
struct llist_node llist;
bool done;
};
struct fixed_file_data {
@ -7323,10 +7324,6 @@ static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
kfree(pfile);
}
spin_lock(&file_data->lock);
list_del(&ref_node->node);
spin_unlock(&file_data->lock);
percpu_ref_exit(&ref_node->refs);
kfree(ref_node);
percpu_ref_put(&file_data->refs);
@ -7353,17 +7350,32 @@ static void io_file_put_work(struct work_struct *work)
static void io_file_data_ref_zero(struct percpu_ref *ref)
{
struct fixed_file_ref_node *ref_node;
struct fixed_file_data *data;
struct io_ring_ctx *ctx;
bool first_add;
bool first_add = false;
int delay = HZ;
ref_node = container_of(ref, struct fixed_file_ref_node, refs);
ctx = ref_node->file_data->ctx;
data = ref_node->file_data;
ctx = data->ctx;
if (percpu_ref_is_dying(&ctx->file_data->refs))
spin_lock(&data->lock);
ref_node->done = true;
while (!list_empty(&data->ref_list)) {
ref_node = list_first_entry(&data->ref_list,
struct fixed_file_ref_node, node);
/* recycle ref nodes in order */
if (!ref_node->done)
break;
list_del(&ref_node->node);
first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist);
}
spin_unlock(&data->lock);
if (percpu_ref_is_dying(&data->refs))
delay = 0;
first_add = llist_add(&ref_node->llist, &ctx->file_put_llist);
if (!delay)
mod_delayed_work(system_wq, &ctx->file_put_work, 0);
else if (first_add)
@ -7387,6 +7399,7 @@ static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
INIT_LIST_HEAD(&ref_node->node);
INIT_LIST_HEAD(&ref_node->file_list);
ref_node->file_data = ctx->file_data;
ref_node->done = false;
return ref_node;
}
@ -7482,7 +7495,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
file_data->node = ref_node;
spin_lock(&file_data->lock);
list_add(&ref_node->node, &file_data->ref_list);
list_add_tail(&ref_node->node, &file_data->ref_list);
spin_unlock(&file_data->lock);
percpu_ref_get(&file_data->refs);
return ret;
@ -7641,7 +7654,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
if (needs_switch) {
percpu_ref_kill(&data->node->refs);
spin_lock(&data->lock);
list_add(&ref_node->node, &data->ref_list);
list_add_tail(&ref_node->node, &data->ref_list);
data->node = ref_node;
spin_unlock(&data->lock);
percpu_ref_get(&ctx->file_data->refs);