linux/fs/io-wq.h
Jens Axboe 7d7230652e io_wq: add get/put_work handlers to io_wq_create()
For cancellation, we need to ensure that the work item stays valid for
as long as ->cur_work is valid. Right now we can't safely dereference
the work item even under the wqe->lock, because while the ->cur_work
pointer will remain valid, the work could be completing and be freed
in parallel.

Only invoke ->get/put_work() on items we know that the caller queued
themselves. Add IO_WQ_WORK_INTERNAL for io-wq to use, which is needed
when we're queueing a flush item, for instance.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-13 11:37:54 -07:00

75 lines
1.9 KiB
C

#ifndef INTERNAL_IO_WQ_H
#define INTERNAL_IO_WQ_H
struct io_wq;
enum {
IO_WQ_WORK_CANCEL = 1,
IO_WQ_WORK_HAS_MM = 2,
IO_WQ_WORK_HASHED = 4,
IO_WQ_WORK_NEEDS_USER = 8,
IO_WQ_WORK_NEEDS_FILES = 16,
IO_WQ_WORK_UNBOUND = 32,
IO_WQ_WORK_INTERNAL = 64,
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 {
struct list_head list;
void (*func)(struct io_wq_work **);
unsigned flags;
struct files_struct *files;
};
#define INIT_IO_WORK(work, _func) \
do { \
(work)->func = _func; \
(work)->flags = 0; \
(work)->files = NULL; \
} while (0) \
typedef void (get_work_fn)(struct io_wq_work *);
typedef void (put_work_fn)(struct io_wq_work *);
struct io_wq *io_wq_create(unsigned bounded, struct mm_struct *mm,
struct user_struct *user,
get_work_fn *get_work, put_work_fn *put_work);
void io_wq_destroy(struct io_wq *wq);
void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
void io_wq_enqueue_hashed(struct io_wq *wq, struct io_wq_work *work, void *val);
void io_wq_flush(struct io_wq *wq);
void io_wq_cancel_all(struct io_wq *wq);
enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork);
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);
#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);
}
#endif