io_uring: keep a pointer ref_node in file_data

->cur_refs of struct fixed_file_data always points to percpu_ref
embedded into struct fixed_file_ref_node. Don't overuse container_of()
and offsetting, and point directly to fixed_file_ref_node.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index fc4ef72..c729ee8 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -210,7 +210,7 @@ struct fixed_file_data {
        struct fixed_file_table         *table;
        struct io_ring_ctx              *ctx;
 
-       struct percpu_ref               *cur_refs;
+       struct fixed_file_ref_node      *node;
        struct percpu_ref               refs;
        struct completion               done;
        struct list_head                ref_list;
@@ -5980,7 +5980,7 @@ static struct file *io_file_get(struct io_submit_state *state,
                fd = array_index_nospec(fd, ctx->nr_user_files);
                file = io_file_from_index(ctx, fd);
                if (file) {
-                       req->fixed_file_refs = ctx->file_data->cur_refs;
+                       req->fixed_file_refs = &ctx->file_data->node->refs;
                        percpu_ref_get(req->fixed_file_refs);
                }
        } else {
@@ -7362,7 +7362,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
                return PTR_ERR(ref_node);
        }
 
-       file_data->cur_refs = &ref_node->refs;
+       file_data->node = ref_node;
        spin_lock(&file_data->lock);
        list_add(&ref_node->node, &file_data->ref_list);
        spin_unlock(&file_data->lock);
@@ -7432,14 +7432,12 @@ static int io_queue_file_removal(struct fixed_file_data *data,
                                 struct file *file)
 {
        struct io_file_put *pfile;
-       struct percpu_ref *refs = data->cur_refs;
-       struct fixed_file_ref_node *ref_node;
+       struct fixed_file_ref_node *ref_node = data->node;
 
        pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
        if (!pfile)
                return -ENOMEM;
 
-       ref_node = container_of(refs, struct fixed_file_ref_node, refs);
        pfile->file = file;
        list_add(&pfile->list, &ref_node->file_list);
 
@@ -7522,10 +7520,10 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
        }
 
        if (needs_switch) {
-               percpu_ref_kill(data->cur_refs);
+               percpu_ref_kill(&data->node->refs);
                spin_lock(&data->lock);
                list_add(&ref_node->node, &data->ref_list);
-               data->cur_refs = &ref_node->refs;
+               data->node = ref_node;
                spin_unlock(&data->lock);
                percpu_ref_get(&ctx->file_data->refs);
        } else