fs/io-wq.h

   1 #ifndef INTERNAL_IO_WQ_H
   2 #define INTERNAL_IO_WQ_H
   3
   4 #include <linux/refcount.h>
   5
   6 struct io_wq;
   7
   8 enum {
   9         IO_WQ_WORK_CANCEL       = 1,
  10         IO_WQ_WORK_HASHED       = 2,
  11         IO_WQ_WORK_UNBOUND      = 4,
  12         IO_WQ_WORK_CONCURRENT   = 16,
  13
  14         IO_WQ_HASH_SHIFT        = 24,   /* upper 8 bits are used for hash key */
  15 };
  16
  17 enum io_wq_cancel {
  18         IO_WQ_CANCEL_OK,        /* cancelled before started */
  19         IO_WQ_CANCEL_RUNNING,   /* found, running, and attempted cancelled */
  20         IO_WQ_CANCEL_NOTFOUND,  /* work not found */
  21 };
  22
  23 struct io_wq_work_node {
  24         struct io_wq_work_node *next;
  25 };
  26
  27 struct io_wq_work_list {
  28         struct io_wq_work_node *first;
  29         struct io_wq_work_node *last;
  30 };
  31
  32 static inline void wq_list_add_after(struct io_wq_work_node *node,
  33                                      struct io_wq_work_node *pos,
  34                                      struct io_wq_work_list *list)
  35 {
  36         struct io_wq_work_node *next = pos->next;
  37
  38         pos->next = node;
  39         node->next = next;
  40         if (!next)
  41                 list->last = node;
  42 }
  43
  44 static inline void wq_list_add_tail(struct io_wq_work_node *node,
  45                                     struct io_wq_work_list *list)
  46 {
  47         node->next = NULL;
  48         if (!list->first) {
  49                 list->last = node;
  50                 WRITE_ONCE(list->first, node);
  51         } else {
  52                 list->last->next = node;
  53                 list->last = node;
  54         }
  55 }
  56
  57 static inline void wq_list_cut(struct io_wq_work_list *list,
  58                                struct io_wq_work_node *last,
  59                                struct io_wq_work_node *prev)
  60 {
  61         /* first in the list, if prev==NULL */
  62         if (!prev)
  63                 WRITE_ONCE(list->first, last->next);
  64         else
  65                 prev->next = last->next;
  66
  67         if (last == list->last)
  68                 list->last = prev;
  69         last->next = NULL;
  70 }
  71
  72 static inline void wq_list_del(struct io_wq_work_list *list,
  73                                struct io_wq_work_node *node,
  74                                struct io_wq_work_node *prev)
  75 {
  76         wq_list_cut(list, node, prev);
  77 }
  78
  79 #define wq_list_for_each(pos, prv, head)                        \
  80         for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
  81
  82 #define wq_list_empty(list)     (READ_ONCE((list)->first) == NULL)
  83 #define INIT_WQ_LIST(list)      do {                            \
  84         (list)->first = NULL;                                   \
  85         (list)->last = NULL;                                    \
  86 } while (0)
  87
  88 struct io_wq_work {
  89         struct io_wq_work_node list;
  90         unsigned flags;
  91 };
  92
  93 static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
  94 {
  95         if (!work->list.next)
  96                 return NULL;
  97
  98         return container_of(work->list.next, struct io_wq_work, list);
  99 }
 100
 101 typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *);
 102 typedef void (io_wq_work_fn)(struct io_wq_work *);
 103
 104 struct io_wq_hash {
 105         refcount_t refs;
 106         unsigned long map;
 107         struct wait_queue_head wait;
 108 };
 109
 110 static inline void io_wq_put_hash(struct io_wq_hash *hash)
 111 {
 112         if (refcount_dec_and_test(&hash->refs))
 113                 kfree(hash);
 114 }
 115
 116 struct io_wq_data {
 117         struct io_wq_hash *hash;
 118         struct task_struct *task;
 119         io_wq_work_fn *do_work;
 120         free_work_fn *free_work;
 121 };
 122
 123 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
 124 void io_wq_exit_start(struct io_wq *wq);
 125 void io_wq_put_and_exit(struct io_wq *wq);
 126
 127 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
 128 void io_wq_hash_work(struct io_wq_work *work, void *val);
 129
 130 int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask);
 131 int io_wq_max_workers(struct io_wq *wq, int *new_count);
 132
 133 static inline bool io_wq_is_hashed(struct io_wq_work *work)
 134 {
 135         return work->flags & IO_WQ_WORK_HASHED;
 136 }
 137
 138 typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 139
 140 enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
 141                                         void *data, bool cancel_all);
 142
 143 #if defined(CONFIG_IO_WQ)
 144 extern void io_wq_worker_sleeping(struct task_struct *);
 145 extern void io_wq_worker_running(struct task_struct *);
 146 #else
 147 static inline void io_wq_worker_sleeping(struct task_struct *tsk)
 148 {
 149 }
 150 static inline void io_wq_worker_running(struct task_struct *tsk)
 151 {
 152 }
 153 #endif
 154
 155 static inline bool io_wq_current_is_worker(void)
 156 {
 157         return in_task() && (current->flags & PF_IO_WORKER) &&
 158                 current->pf_io_worker;
 159 }
 160 #endif