linux-stable/fs/io-wq.h
Hao Xu 24115c4e95 io-wq: add helper to merge two wq_lists
add a helper to merge two wq_lists, it will be useful in the next
patches.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211207093951.247840-2-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-07 15:01:57 -07:00

227 lines
5.1 KiB
C

#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;
};
#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
#define wq_list_for_each_resume(pos, prv) \
for (; 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; \
} while (0)
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;
}
/**
* wq_list_merge - merge the second list to the first one.
* @list0: the first list
* @list1: the second list
* Return the first node after mergence.
*/
static inline struct io_wq_work_node *wq_list_merge(struct io_wq_work_list *list0,
struct io_wq_work_list *list1)
{
struct io_wq_work_node *ret;
if (!list0->first) {
ret = list1->first;
} else {
ret = list0->first;
list0->last->next = list1->first;
}
INIT_WQ_LIST(list0);
INIT_WQ_LIST(list1);
return ret;
}
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_add_head(struct io_wq_work_node *node,
struct io_wq_work_list *list)
{
node->next = list->first;
if (!node->next)
list->last = node;
WRITE_ONCE(list->first, 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_splice(struct io_wq_work_list *list,
struct io_wq_work_node *to)
{
list->last->next = to->next;
to->next = list->first;
INIT_WQ_LIST(list);
}
static inline bool wq_list_splice(struct io_wq_work_list *list,
struct io_wq_work_node *to)
{
if (!wq_list_empty(list)) {
__wq_list_splice(list, to);
return true;
}
return false;
}
static inline void wq_stack_add_head(struct io_wq_work_node *node,
struct io_wq_work_node *stack)
{
node->next = stack->next;
stack->next = node;
}
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);
}
static inline
struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
{
struct io_wq_work_node *node = stack->next;
stack->next = node->next;
return node;
}
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