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_HASHED       = 4,
   9         IO_WQ_WORK_UNBOUND      = 32,
  10         IO_WQ_WORK_NO_CANCEL    = 256,
  11         IO_WQ_WORK_CONCURRENT   = 512,
  12
  13         IO_WQ_HASH_SHIFT        = 24,   /* upper 8 bits are used for hash key */
  14 };
  15
  16 enum io_wq_cancel {
  17         IO_WQ_CANCEL_OK,        /* cancelled before started */
  18         IO_WQ_CANCEL_RUNNING,   /* found, running, and attempted cancelled */
  19         IO_WQ_CANCEL_NOTFOUND,  /* work not found */
  20 };
  21
  22 struct io_wq_work_node {
  23         struct io_wq_work_node *next;
  24 };
  25
  26 struct io_wq_work_list {
  27         struct io_wq_work_node *first;
  28         struct io_wq_work_node *last;
  29 };
  30
  31 static inline void wq_list_add_after(struct io_wq_work_node *node,
  32                                      struct io_wq_work_node *pos,
  33                                      struct io_wq_work_list *list)
  34 {
  35         struct io_wq_work_node *next = pos->next;
  36
  37         pos->next = node;
  38         node->next = next;
  39         if (!next)
  40                 list->last = node;
  41 }
  42
  43 static inline void wq_list_add_tail(struct io_wq_work_node *node,
  44                                     struct io_wq_work_list *list)
  45 {
  46         if (!list->first) {
  47                 list->last = node;
  48                 WRITE_ONCE(list->first, node);
  49         } else {
  50                 list->last->next = node;
  51                 list->last = node;
  52         }
  53 }
  54
  55 static inline void wq_list_cut(struct io_wq_work_list *list,
  56                                struct io_wq_work_node *last,
  57                                struct io_wq_work_node *prev)
  58 {
  59         /* first in the list, if prev==NULL */
  60         if (!prev)
  61                 WRITE_ONCE(list->first, last->next);
  62         else
  63                 prev->next = last->next;
  64
  65         if (last == list->last)
  66                 list->last = prev;
  67         last->next = NULL;
  68 }
  69
  70 static inline void wq_list_del(struct io_wq_work_list *list,
  71                                struct io_wq_work_node *node,
  72                                struct io_wq_work_node *prev)
  73 {
  74         wq_list_cut(list, node, prev);
  75 }
  76
  77 #define wq_list_for_each(pos, prv, head)                        \
  78         for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
  79
  80 #define wq_list_empty(list)     (READ_ONCE((list)->first) == NULL)
  81 #define INIT_WQ_LIST(list)      do {                            \
  82         (list)->first = NULL;                                   \
  83         (list)->last = NULL;                                    \
  84 } while (0)
  85
  86 struct io_wq_work {
  87         struct io_wq_work_node list;
  88         void (*func)(struct io_wq_work **);
  89         struct files_struct *files;
  90         struct mm_struct *mm;
  91         const struct cred *creds;
  92         struct fs_struct *fs;
  93         unsigned flags;
  94         pid_t task_pid;
  95 };
  96
  97 #define INIT_IO_WORK(work, _func)                               \
  98         do {                                                    \
  99                 *(work) = (struct io_wq_work){ .func = _func }; \
 100         } while (0)                                             \
 101
 102 static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
 103 {
 104         if (!work->list.next)
 105                 return NULL;
 106
 107         return container_of(work->list.next, struct io_wq_work, list);
 108 }
 109
 110 typedef void (free_work_fn)(struct io_wq_work *);
 111
 112 struct io_wq_data {
 113         struct user_struct *user;
 114
 115         free_work_fn *free_work;
 116 };
 117
 118 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
 119 bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
 120 void io_wq_destroy(struct io_wq *wq);
 121
 122 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
 123 void io_wq_hash_work(struct io_wq_work *work, void *val);
 124
 125 static inline bool io_wq_is_hashed(struct io_wq_work *work)
 126 {
 127         return work->flags & IO_WQ_WORK_HASHED;
 128 }
 129
 130 void io_wq_cancel_all(struct io_wq *wq);
 131 enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork);
 132 enum io_wq_cancel io_wq_cancel_pid(struct io_wq *wq, pid_t pid);
 133
 134 typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 135
 136 enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
 137                                         void *data);
 138
 139 struct task_struct *io_wq_get_task(struct io_wq *wq);
 140
 141 #if defined(CONFIG_IO_WQ)
 142 extern void io_wq_worker_sleeping(struct task_struct *);
 143 extern void io_wq_worker_running(struct task_struct *);
 144 #else
 145 static inline void io_wq_worker_sleeping(struct task_struct *tsk)
 146 {
 147 }
 148 static inline void io_wq_worker_running(struct task_struct *tsk)
 149 {
 150 }
 151 #endif
 152
 153 static inline bool io_wq_current_is_worker(void)
 154 {
 155         return in_task() && (current->flags & PF_IO_WORKER);
 156 }
 157 #endif