io_uring: import 5.15-stable io_uring

No upstream commit exists.

This imports the io_uring codebase from 5.15.85, wholesale. Changes
from that code base:

- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10.
- Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports,
  and we don't support these in 5.10 to begin with.
- sock_from_file() old style calling convention.
- Use compat_get_bitmap() only for CONFIG_COMPAT=y

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 160 insertions, 0 deletions

diff --git a/io_uring/io-wq.h b/io_uring/io-wq.h
new file mode 100644
index 000000000000..bf5c4c533760
--- /dev/null
+++ b/io_uring/io-wq.h
@@ -0,0 +1,160 @@
+#ifndef INTERNAL_IO_WQ_H
+#define INTERNAL_IO_WQ_H
+
+#include <linux/refcount.h>
+
+struct io_wq;
+
+enum {
+	IO_WQ_WORK_CANCEL	= 1,
+	IO_WQ_WORK_HASHED	= 2,
+	IO_WQ_WORK_UNBOUND	= 4,
+	IO_WQ_WORK_CONCURRENT	= 16,
+
+	IO_WQ_HASH_SHIFT	= 24,	/* upper 8 bits are used for hash key */
+};
+
+enum io_wq_cancel {
+	IO_WQ_CANCEL_OK,	/* cancelled before started */
+	IO_WQ_CANCEL_RUNNING,	/* found, running, and attempted cancelled */
+	IO_WQ_CANCEL_NOTFOUND,	/* work not found */
+};
+
+struct io_wq_work_node {
+	struct io_wq_work_node *next;
+};
+
+struct io_wq_work_list {
+	struct io_wq_work_node *first;
+	struct io_wq_work_node *last;
+};
+
+static inline void wq_list_add_after(struct io_wq_work_node *node,
+				     struct io_wq_work_node *pos,
+				     struct io_wq_work_list *list)
+{
+	struct io_wq_work_node *next = pos->next;
+
+	pos->next = node;
+	node->next = next;
+	if (!next)
+		list->last = node;
+}
+
+static inline void wq_list_add_tail(struct io_wq_work_node *node,
+				    struct io_wq_work_list *list)
+{
+	node->next = NULL;
+	if (!list->first) {
+		list->last = node;
+		WRITE_ONCE(list->first, node);
+	} else {
+		list->last->next = node;
+		list->last = node;
+	}
+}
+
+static inline void wq_list_cut(struct io_wq_work_list *list,
+			       struct io_wq_work_node *last,
+			       struct io_wq_work_node *prev)
+{
+	/* first in the list, if prev==NULL */
+	if (!prev)
+		WRITE_ONCE(list->first, last->next);
+	else
+		prev->next = last->next;
+
+	if (last == list->last)
+		list->last = prev;
+	last->next = NULL;
+}
+
+static inline void wq_list_del(struct io_wq_work_list *list,
+			       struct io_wq_work_node *node,
+			       struct io_wq_work_node *prev)
+{
+	wq_list_cut(list, node, prev);
+}
+
+#define wq_list_for_each(pos, prv, head)			\
+	for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
+
+#define wq_list_empty(list)	(READ_ONCE((list)->first) == NULL)
+#define INIT_WQ_LIST(list)	do {				\
+	(list)->first = NULL;					\
+	(list)->last = NULL;					\
+} while (0)
+
+struct io_wq_work {
+	struct io_wq_work_node list;
+	unsigned flags;
+};
+
+static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
+{
+	if (!work->list.next)
+		return NULL;
+
+	return container_of(work->list.next, struct io_wq_work, list);
+}
+
+typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *);
+typedef void (io_wq_work_fn)(struct io_wq_work *);
+
+struct io_wq_hash {
+	refcount_t refs;
+	unsigned long map;
+	struct wait_queue_head wait;
+};
+
+static inline void io_wq_put_hash(struct io_wq_hash *hash)
+{
+	if (refcount_dec_and_test(&hash->refs))
+		kfree(hash);
+}
+
+struct io_wq_data {
+	struct io_wq_hash *hash;
+	struct task_struct *task;
+	io_wq_work_fn *do_work;
+	free_work_fn *free_work;
+};
+
+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
+void io_wq_exit_start(struct io_wq *wq);
+void io_wq_put_and_exit(struct io_wq *wq);
+
+void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
+void io_wq_hash_work(struct io_wq_work *work, void *val);
+
+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask);
+int io_wq_max_workers(struct io_wq *wq, int *new_count);
+
+static inline bool io_wq_is_hashed(struct io_wq_work *work)
+{
+	return work->flags & IO_WQ_WORK_HASHED;
+}
+
+typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
+
+enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
+					void *data, bool cancel_all);
+
+#if defined(CONFIG_IO_WQ)
+extern void io_wq_worker_sleeping(struct task_struct *);
+extern void io_wq_worker_running(struct task_struct *);
+#else
+static inline void io_wq_worker_sleeping(struct task_struct *tsk)
+{
+}
+static inline void io_wq_worker_running(struct task_struct *tsk)
+{
+}
+#endif
+
+static inline bool io_wq_current_is_worker(void)
+{
+	return in_task() && (current->flags & PF_IO_WORKER) &&
+		current->pf_io_worker;
+}
+#endif