diff options
Diffstat (limited to 'include/linux/pipe_fs_i.h')
| -rw-r--r-- | include/linux/pipe_fs_i.h | 29 |
1 files changed, 9 insertions, 20 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index cb0fd633a610..6cb65df3e3ba 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -157,26 +157,6 @@ static inline bool pipe_full(unsigned int head, unsigned int tail, } /** - * pipe_space_for_user - Return number of slots available to userspace - * @head: The pipe ring head pointer - * @tail: The pipe ring tail pointer - * @pipe: The pipe info structure - */ -static inline unsigned int pipe_space_for_user(unsigned int head, unsigned int tail, - struct pipe_inode_info *pipe) -{ - unsigned int p_occupancy, p_space; - - p_occupancy = pipe_occupancy(head, tail); - if (p_occupancy >= pipe->max_usage) - return 0; - p_space = pipe->ring_size - p_occupancy; - if (p_space > pipe->max_usage) - p_space = pipe->max_usage; - return p_space; -} - -/** * pipe_buf_get - get a reference to a pipe_buffer * @pipe: the pipe that the buffer belongs to * @buf: the buffer to get a reference to @@ -229,6 +209,15 @@ static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe, return buf->ops->try_steal(pipe, buf); } +static inline void pipe_discard_from(struct pipe_inode_info *pipe, + unsigned int old_head) +{ + unsigned int mask = pipe->ring_size - 1; + + while (pipe->head > old_head) + pipe_buf_release(pipe, &pipe->bufs[--pipe->head & mask]); +} + /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual memory allocation, whereas PIPE_BUF makes atomicity guarantees. */ #define PIPE_SIZE PAGE_SIZE |