diff options
Diffstat (limited to 'include/linux/pipe_fs_i.h')
| -rw-r--r-- | include/linux/pipe_fs_i.h | 67 |
1 files changed, 47 insertions, 20 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index ae58fad7f1e0..50afd0d0084c 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -8,6 +8,11 @@ #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ #define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */ +#define PIPE_BUF_FLAG_CAN_MERGE 0x10 /* can merge buffers */ +#define PIPE_BUF_FLAG_WHOLE 0x20 /* read() must return entire buffer or error */ +#ifdef CONFIG_WATCH_QUEUE +#define PIPE_BUF_FLAG_LOSS 0x40 /* Message loss happened after this buffer */ +#endif /** * struct pipe_buffer - a linux kernel pipe buffer @@ -33,8 +38,10 @@ struct pipe_buffer { * @wr_wait: writer wait point in case of full pipe * @head: The point of buffer production * @tail: The point of buffer consumption + * @note_loss: The next read() should insert a data-lost message * @max_usage: The maximum number of slots that may be used in the ring * @ring_size: total number of buffers (should be a power of 2) + * @nr_accounted: The amount this pipe accounts for in user->pipe_bufs * @tmp_page: cached released page * @readers: number of current readers of this pipe * @writers: number of current writers of this pipe @@ -45,6 +52,7 @@ struct pipe_buffer { * @fasync_writers: writer side fasync * @bufs: the circular array of pipe buffers * @user: the user who created this pipe + * @watch_queue: If this pipe is a watch_queue, this is the stuff for that **/ struct pipe_inode_info { struct mutex mutex; @@ -53,6 +61,10 @@ struct pipe_inode_info { unsigned int tail; unsigned int max_usage; unsigned int ring_size; +#ifdef CONFIG_WATCH_QUEUE + bool note_loss; +#endif + unsigned int nr_accounted; unsigned int readers; unsigned int writers; unsigned int files; @@ -63,17 +75,20 @@ struct pipe_inode_info { struct fasync_struct *fasync_writers; struct pipe_buffer *bufs; struct user_struct *user; +#ifdef CONFIG_WATCH_QUEUE + struct watch_queue *watch_queue; +#endif }; /* * Note on the nesting of these functions: * * ->confirm() - * ->steal() + * ->try_steal() * - * That is, ->steal() must be called on a confirmed buffer. - * See below for the meaning of each operation. Also see kerneldoc - * in fs/pipe.c for the pipe and generic variants of these hooks. + * That is, ->try_steal() must be called on a confirmed buffer. See below for + * the meaning of each operation. Also see the kerneldoc in fs/pipe.c for the + * pipe and generic variants of these hooks. */ struct pipe_buf_operations { /* @@ -81,7 +96,7 @@ struct pipe_buf_operations { * and that the contents are good. If the pages in the pipe belong * to a file system, we may need to wait for IO completion in this * hook. Returns 0 for good, or a negative error value in case of - * error. + * error. If not present all pages are considered good. */ int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *); @@ -93,13 +108,13 @@ struct pipe_buf_operations { /* * Attempt to take ownership of the pipe buffer and its contents. - * ->steal() returns 0 for success, in which case the contents - * of the pipe (the buf->page) is locked and now completely owned - * by the caller. The page may then be transferred to a different - * mapping, the most often used case is insertion into different - * file address space cache. + * ->try_steal() returns %true for success, in which case the contents + * of the pipe (the buf->page) is locked and now completely owned by the + * caller. The page may then be transferred to a different mapping, the + * most often used case is insertion into different file address space + * cache. */ - int (*steal)(struct pipe_inode_info *, struct pipe_buffer *); + bool (*try_steal)(struct pipe_inode_info *, struct pipe_buffer *); /* * Get a reference to the pipe buffer. @@ -194,18 +209,22 @@ static inline void pipe_buf_release(struct pipe_inode_info *pipe, static inline int pipe_buf_confirm(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { + if (!buf->ops->confirm) + return 0; return buf->ops->confirm(pipe, buf); } /** - * pipe_buf_steal - attempt to take ownership of a pipe_buffer + * pipe_buf_try_steal - attempt to take ownership of a pipe_buffer * @pipe: the pipe that the buffer belongs to * @buf: the buffer to attempt to steal */ -static inline int pipe_buf_steal(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) +static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { - return buf->ops->steal(pipe, buf); + if (!buf->ops->try_steal) + return false; + return buf->ops->try_steal(pipe, buf); } /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual @@ -229,17 +248,25 @@ void free_pipe_info(struct pipe_inode_info *); /* Generic pipe buffer ops functions */ bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); -int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); -int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); -int generic_pipe_buf_nosteal(struct pipe_inode_info *, struct pipe_buffer *); +bool generic_pipe_buf_try_steal(struct pipe_inode_info *, struct pipe_buffer *); void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); -void pipe_buf_mark_unmergeable(struct pipe_buffer *buf); extern const struct pipe_buf_operations nosteal_pipe_buf_ops; +#ifdef CONFIG_WATCH_QUEUE +unsigned long account_pipe_buffers(struct user_struct *user, + unsigned long old, unsigned long new); +bool too_many_pipe_buffers_soft(unsigned long user_bufs); +bool too_many_pipe_buffers_hard(unsigned long user_bufs); +bool pipe_is_unprivileged_user(void); +#endif + /* for F_SETPIPE_SZ and F_GETPIPE_SZ */ +#ifdef CONFIG_WATCH_QUEUE +int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots); +#endif long pipe_fcntl(struct file *, unsigned int, unsigned long arg); -struct pipe_inode_info *get_pipe_info(struct file *file); +struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice); int create_pipe_files(struct file **, int); unsigned int round_pipe_size(unsigned long size); |