1
2#ifndef _LINUX_PIPE_FS_I_H
3#define _LINUX_PIPE_FS_I_H
4
5#define PIPE_DEF_BUFFERS 16
6
7#define PIPE_BUF_FLAG_LRU 0x01
8#define PIPE_BUF_FLAG_ATOMIC 0x02
9#define PIPE_BUF_FLAG_GIFT 0x04
10#define PIPE_BUF_FLAG_PACKET 0x08
11#define PIPE_BUF_FLAG_CAN_MERGE 0x10
12#define PIPE_BUF_FLAG_WHOLE 0x20
13#ifdef CONFIG_WATCH_QUEUE
14#define PIPE_BUF_FLAG_LOSS 0x40
15#endif
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26struct pipe_buffer {
27 struct page *page;
28 unsigned int offset, len;
29 const struct pipe_buf_operations *ops;
30 unsigned int flags;
31 unsigned long private;
32};
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57struct pipe_inode_info {
58 struct mutex mutex;
59 wait_queue_head_t rd_wait, wr_wait;
60 unsigned int head;
61 unsigned int tail;
62 unsigned int max_usage;
63 unsigned int ring_size;
64#ifdef CONFIG_WATCH_QUEUE
65 bool note_loss;
66#endif
67 unsigned int nr_accounted;
68 unsigned int readers;
69 unsigned int writers;
70 unsigned int files;
71 unsigned int r_counter;
72 unsigned int w_counter;
73 struct page *tmp_page;
74 struct fasync_struct *fasync_readers;
75 struct fasync_struct *fasync_writers;
76 struct pipe_buffer *bufs;
77 struct user_struct *user;
78#ifdef CONFIG_WATCH_QUEUE
79 struct watch_queue *watch_queue;
80#endif
81};
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93struct pipe_buf_operations {
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101 int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *);
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107 void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
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117 bool (*try_steal)(struct pipe_inode_info *, struct pipe_buffer *);
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122 bool (*get)(struct pipe_inode_info *, struct pipe_buffer *);
123};
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130static inline bool pipe_empty(unsigned int head, unsigned int tail)
131{
132 return head == tail;
133}
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140static inline unsigned int pipe_occupancy(unsigned int head, unsigned int tail)
141{
142 return head - tail;
143}
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151static inline bool pipe_full(unsigned int head, unsigned int tail,
152 unsigned int limit)
153{
154 return pipe_occupancy(head, tail) >= limit;
155}
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163static inline unsigned int pipe_space_for_user(unsigned int head, unsigned int tail,
164 struct pipe_inode_info *pipe)
165{
166 unsigned int p_occupancy, p_space;
167
168 p_occupancy = pipe_occupancy(head, tail);
169 if (p_occupancy >= pipe->max_usage)
170 return 0;
171 p_space = pipe->ring_size - p_occupancy;
172 if (p_space > pipe->max_usage)
173 p_space = pipe->max_usage;
174 return p_space;
175}
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184static inline __must_check bool pipe_buf_get(struct pipe_inode_info *pipe,
185 struct pipe_buffer *buf)
186{
187 return buf->ops->get(pipe, buf);
188}
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195static inline void pipe_buf_release(struct pipe_inode_info *pipe,
196 struct pipe_buffer *buf)
197{
198 const struct pipe_buf_operations *ops = buf->ops;
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200 buf->ops = NULL;
201 ops->release(pipe, buf);
202}
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209static inline int pipe_buf_confirm(struct pipe_inode_info *pipe,
210 struct pipe_buffer *buf)
211{
212 if (!buf->ops->confirm)
213 return 0;
214 return buf->ops->confirm(pipe, buf);
215}
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222static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe,
223 struct pipe_buffer *buf)
224{
225 if (!buf->ops->try_steal)
226 return false;
227 return buf->ops->try_steal(pipe, buf);
228}
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231
232#define PIPE_SIZE PAGE_SIZE
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235void pipe_lock(struct pipe_inode_info *);
236void pipe_unlock(struct pipe_inode_info *);
237void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
238
239extern unsigned int pipe_max_size;
240extern unsigned long pipe_user_pages_hard;
241extern unsigned long pipe_user_pages_soft;
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244void pipe_wait(struct pipe_inode_info *pipe);
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246struct pipe_inode_info *alloc_pipe_info(void);
247void free_pipe_info(struct pipe_inode_info *);
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250bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
251bool generic_pipe_buf_try_steal(struct pipe_inode_info *, struct pipe_buffer *);
252void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
253
254extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
255
256#ifdef CONFIG_WATCH_QUEUE
257unsigned long account_pipe_buffers(struct user_struct *user,
258 unsigned long old, unsigned long new);
259bool too_many_pipe_buffers_soft(unsigned long user_bufs);
260bool too_many_pipe_buffers_hard(unsigned long user_bufs);
261bool pipe_is_unprivileged_user(void);
262#endif
263
264
265#ifdef CONFIG_WATCH_QUEUE
266int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots);
267#endif
268long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
269struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice);
270
271int create_pipe_files(struct file **, int);
272unsigned int round_pipe_size(unsigned long size);
273
274#endif
275