fs/io-wq.h

   1 #ifndef INTERNAL_IO_WQ_H
   2 #define INTERNAL_IO_WQ_H
   3
   4 struct io_wq;
   5
   6 enum {
   7         IO_WQ_WORK_CANCEL       = 1,
   8         IO_WQ_WORK_HAS_MM       = 2,
   9         IO_WQ_WORK_HASHED       = 4,
  10         IO_WQ_WORK_UNBOUND      = 32,
  11         IO_WQ_WORK_INTERNAL     = 64,
  12         IO_WQ_WORK_CB           = 128,
  13         IO_WQ_WORK_NO_CANCEL    = 256,
  14         IO_WQ_WORK_CONCURRENT   = 512,
  15
  16         IO_WQ_HASH_SHIFT        = 24,   /* upper 8 bits are used for hash key */
  17 };
  18
  19 enum io_wq_cancel {
  20         IO_WQ_CANCEL_OK,        /* cancelled before started */
  21         IO_WQ_CANCEL_RUNNING,   /* found, running, and attempted cancelled */
  22         IO_WQ_CANCEL_NOTFOUND,  /* work not found */
  23 };
  24
  25 struct io_wq_work_node {
  26         struct io_wq_work_node *next;
  27 };
  28
  29 struct io_wq_work_list {
  30         struct io_wq_work_node *first;
  31         struct io_wq_work_node *last;
  32 };
  33
  34 static inline void wq_list_add_tail(struct io_wq_work_node *node,
  35                                     struct io_wq_work_list *list)
  36 {
  37         if (!list->first) {
  38                 list->last = node;
  39                 WRITE_ONCE(list->first, node);
  40         } else {
  41                 list->last->next = node;
  42                 list->last = node;
  43         }
  44 }
  45
  46 static inline void wq_node_del(struct io_wq_work_list *list,
  47                                struct io_wq_work_node *node,
  48                                struct io_wq_work_node *prev)
  49 {
  50         if (node == list->first)
  51                 WRITE_ONCE(list->first, node->next);
  52         if (node == list->last)
  53                 list->last = prev;
  54         if (prev)
  55                 prev->next = node->next;
  56         node->next = NULL;
  57 }
  58
  59 #define wq_list_for_each(pos, prv, head)                        \
  60         for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
  61
  62 #define wq_list_empty(list)     (READ_ONCE((list)->first) == NULL)
  63 #define INIT_WQ_LIST(list)      do {                            \
  64         (list)->first = NULL;                                   \
  65         (list)->last = NULL;                                    \
  66 } while (0)
  67
  68 struct io_wq_work {
  69         union {
  70                 struct io_wq_work_node list;
  71                 void *data;
  72         };
  73         void (*func)(struct io_wq_work **);
  74         struct files_struct *files;
  75         struct mm_struct *mm;
  76         const struct cred *creds;
  77         unsigned flags;
  78 };
  79
  80 #define INIT_IO_WORK(work, _func)                       \
  81         do {                                            \
  82                 (work)->list.next = NULL;               \
  83                 (work)->func = _func;                   \
  84                 (work)->flags = 0;                      \
  85                 (work)->files = NULL;                   \
  86                 (work)->mm = NULL;                      \
  87                 (work)->creds = NULL;                   \
  88         } while (0)                                     \
  89
  90 typedef void (get_work_fn)(struct io_wq_work *);
  91 typedef void (put_work_fn)(struct io_wq_work *);
  92
  93 struct io_wq_data {
  94         struct user_struct *user;
  95
  96         get_work_fn *get_work;
  97         put_work_fn *put_work;
  98 };
  99
 100 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
 101 bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
 102 void io_wq_destroy(struct io_wq *wq);
 103
 104 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
 105 void io_wq_enqueue_hashed(struct io_wq *wq, struct io_wq_work *work, void *val);
 106 void io_wq_flush(struct io_wq *wq);
 107
 108 void io_wq_cancel_all(struct io_wq *wq);
 109 enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork);
 110
 111 typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 112
 113 enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
 114                                         void *data);
 115
 116 #if defined(CONFIG_IO_WQ)
 117 extern void io_wq_worker_sleeping(struct task_struct *);
 118 extern void io_wq_worker_running(struct task_struct *);
 119 #else
 120 static inline void io_wq_worker_sleeping(struct task_struct *tsk)
 121 {
 122 }
 123 static inline void io_wq_worker_running(struct task_struct *tsk)
 124 {
 125 }
 126 #endif
 127
 128 static inline bool io_wq_current_is_worker(void)
 129 {
 130         return in_task() && (current->flags & PF_IO_WORKER);
 131 }
 132 #endif