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 #define wq_list_for_each(pos, prv, head)                        \
  33         for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
  34
  35 #define wq_list_for_each_resume(pos, prv)                       \
  36         for (; pos; prv = pos, pos = (pos)->next)
  37
  38 #define wq_list_empty(list)     (READ_ONCE((list)->first) == NULL)
  39 #define INIT_WQ_LIST(list)      do {                            \
  40         (list)->first = NULL;                                   \
  41 } while (0)
  42
  43 static inline void wq_list_add_after(struct io_wq_work_node *node,
  44                                      struct io_wq_work_node *pos,
  45                                      struct io_wq_work_list *list)
  46 {
  47         struct io_wq_work_node *next = pos->next;
  48
  49         pos->next = node;
  50         node->next = next;
  51         if (!next)
  52                 list->last = node;
  53 }
  54
  55 /**
  56  * wq_list_merge - merge the second list to the first one.
  57  * @list0: the first list
  58  * @list1: the second list
  59  * Return the first node after mergence.
  60  */
  61 static inline struct io_wq_work_node *wq_list_merge(struct io_wq_work_list *list0,
  62                                                     struct io_wq_work_list *list1)
  63 {
  64         struct io_wq_work_node *ret;
  65
  66         if (!list0->first) {
  67                 ret = list1->first;
  68         } else {
  69                 ret = list0->first;
  70                 list0->last->next = list1->first;
  71         }
  72         INIT_WQ_LIST(list0);
  73         INIT_WQ_LIST(list1);
  74         return ret;
  75 }
  76
  77 static inline void wq_list_add_tail(struct io_wq_work_node *node,
  78                                     struct io_wq_work_list *list)
  79 {
  80         node->next = NULL;
  81         if (!list->first) {
  82                 list->last = node;
  83                 WRITE_ONCE(list->first, node);
  84         } else {
  85                 list->last->next = node;
  86                 list->last = node;
  87         }
  88 }
  89
  90 static inline void wq_list_add_head(struct io_wq_work_node *node,
  91                                     struct io_wq_work_list *list)
  92 {
  93         node->next = list->first;
  94         if (!node->next)
  95                 list->last = node;
  96         WRITE_ONCE(list->first, node);
  97 }
  98
  99 static inline void wq_list_cut(struct io_wq_work_list *list,
 100                                struct io_wq_work_node *last,
 101                                struct io_wq_work_node *prev)
 102 {
 103         /* first in the list, if prev==NULL */
 104         if (!prev)
 105                 WRITE_ONCE(list->first, last->next);
 106         else
 107                 prev->next = last->next;
 108
 109         if (last == list->last)
 110                 list->last = prev;
 111         last->next = NULL;
 112 }
 113
 114 static inline void __wq_list_splice(struct io_wq_work_list *list,
 115                                     struct io_wq_work_node *to)
 116 {
 117         list->last->next = to->next;
 118         to->next = list->first;
 119         INIT_WQ_LIST(list);
 120 }
 121
 122 static inline bool wq_list_splice(struct io_wq_work_list *list,
 123                                   struct io_wq_work_node *to)
 124 {
 125         if (!wq_list_empty(list)) {
 126                 __wq_list_splice(list, to);
 127                 return true;
 128         }
 129         return false;
 130 }
 131
 132 static inline void wq_stack_add_head(struct io_wq_work_node *node,
 133                                      struct io_wq_work_node *stack)
 134 {
 135         node->next = stack->next;
 136         stack->next = node;
 137 }
 138
 139 static inline void wq_list_del(struct io_wq_work_list *list,
 140                                struct io_wq_work_node *node,
 141                                struct io_wq_work_node *prev)
 142 {
 143         wq_list_cut(list, node, prev);
 144 }
 145
 146 static inline
 147 struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
 148 {
 149         struct io_wq_work_node *node = stack->next;
 150
 151         stack->next = node->next;
 152         return node;
 153 }
 154
 155 struct io_wq_work {
 156         struct io_wq_work_node list;
 157         unsigned flags;
 158         int cancel_seq;
 159 };
 160
 161 static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
 162 {
 163         if (!work->list.next)
 164                 return NULL;
 165
 166         return container_of(work->list.next, struct io_wq_work, list);
 167 }
 168
 169 typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *);
 170 typedef void (io_wq_work_fn)(struct io_wq_work *);
 171
 172 struct io_wq_hash {
 173         refcount_t refs;
 174         unsigned long map;
 175         struct wait_queue_head wait;
 176 };
 177
 178 static inline void io_wq_put_hash(struct io_wq_hash *hash)
 179 {
 180         if (refcount_dec_and_test(&hash->refs))
 181                 kfree(hash);
 182 }
 183
 184 struct io_wq_data {
 185         struct io_wq_hash *hash;
 186         struct task_struct *task;
 187         io_wq_work_fn *do_work;
 188         free_work_fn *free_work;
 189 };
 190
 191 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
 192 void io_wq_exit_start(struct io_wq *wq);
 193 void io_wq_put_and_exit(struct io_wq *wq);
 194
 195 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
 196 void io_wq_hash_work(struct io_wq_work *work, void *val);
 197
 198 int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask);
 199 int io_wq_max_workers(struct io_wq *wq, int *new_count);
 200
 201 static inline bool io_wq_is_hashed(struct io_wq_work *work)
 202 {
 203         return work->flags & IO_WQ_WORK_HASHED;
 204 }
 205
 206 typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 207
 208 enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
 209                                         void *data, bool cancel_all);
 210
 211 #if defined(CONFIG_IO_WQ)
 212 extern void io_wq_worker_sleeping(struct task_struct *);
 213 extern void io_wq_worker_running(struct task_struct *);
 214 #else
 215 static inline void io_wq_worker_sleeping(struct task_struct *tsk)
 216 {
 217 }
 218 static inline void io_wq_worker_running(struct task_struct *tsk)
 219 {
 220 }
 221 #endif
 222
 223 static inline bool io_wq_current_is_worker(void)
 224 {
 225         return in_task() && (current->flags & PF_IO_WORKER) &&
 226                 current->worker_private;
 227 }
 228 #endif