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![Linus Torvalds](/assets/img/avatar_default.png)
Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
149 lines
4.9 KiB
C
149 lines
4.9 KiB
C
#ifndef _LINUX_PIPE_FS_I_H
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#define _LINUX_PIPE_FS_I_H
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#define PIPE_DEF_BUFFERS 16
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#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
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#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
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#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
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#define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */
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/**
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* struct pipe_buffer - a linux kernel pipe buffer
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* @page: the page containing the data for the pipe buffer
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* @offset: offset of data inside the @page
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* @len: length of data inside the @page
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* @ops: operations associated with this buffer. See @pipe_buf_operations.
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* @flags: pipe buffer flags. See above.
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* @private: private data owned by the ops.
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**/
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struct pipe_buffer {
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struct page *page;
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unsigned int offset, len;
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const struct pipe_buf_operations *ops;
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unsigned int flags;
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unsigned long private;
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};
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/**
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* struct pipe_inode_info - a linux kernel pipe
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* @mutex: mutex protecting the whole thing
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* @wait: reader/writer wait point in case of empty/full pipe
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* @nrbufs: the number of non-empty pipe buffers in this pipe
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* @buffers: total number of buffers (should be a power of 2)
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* @curbuf: the current pipe buffer entry
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* @tmp_page: cached released page
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* @readers: number of current readers of this pipe
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* @writers: number of current writers of this pipe
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* @files: number of struct file referring this pipe (protected by ->i_lock)
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* @waiting_writers: number of writers blocked waiting for room
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* @r_counter: reader counter
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* @w_counter: writer counter
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* @fasync_readers: reader side fasync
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* @fasync_writers: writer side fasync
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* @bufs: the circular array of pipe buffers
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**/
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struct pipe_inode_info {
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struct mutex mutex;
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wait_queue_head_t wait;
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unsigned int nrbufs, curbuf, buffers;
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unsigned int readers;
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unsigned int writers;
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unsigned int files;
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unsigned int waiting_writers;
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unsigned int r_counter;
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unsigned int w_counter;
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struct page *tmp_page;
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struct fasync_struct *fasync_readers;
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struct fasync_struct *fasync_writers;
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struct pipe_buffer *bufs;
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};
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/*
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* Note on the nesting of these functions:
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*
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* ->confirm()
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* ->steal()
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* ...
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* ->map()
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* ...
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* ->unmap()
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*
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* That is, ->map() must be called on a confirmed buffer,
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* same goes for ->steal(). See below for the meaning of each
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* operation. Also see kerneldoc in fs/pipe.c for the pipe
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* and generic variants of these hooks.
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*/
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struct pipe_buf_operations {
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/*
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* This is set to 1, if the generic pipe read/write may coalesce
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* data into an existing buffer. If this is set to 0, a new pipe
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* page segment is always used for new data.
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*/
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int can_merge;
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/*
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* ->confirm() verifies that the data in the pipe buffer is there
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* and that the contents are good. If the pages in the pipe belong
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* to a file system, we may need to wait for IO completion in this
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* hook. Returns 0 for good, or a negative error value in case of
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* error.
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*/
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int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *);
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/*
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* When the contents of this pipe buffer has been completely
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* consumed by a reader, ->release() is called.
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*/
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void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
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/*
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* Attempt to take ownership of the pipe buffer and its contents.
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* ->steal() returns 0 for success, in which case the contents
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* of the pipe (the buf->page) is locked and now completely owned
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* by the caller. The page may then be transferred to a different
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* mapping, the most often used case is insertion into different
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* file address space cache.
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*/
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int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
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/*
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* Get a reference to the pipe buffer.
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*/
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void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
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};
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/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
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memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
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#define PIPE_SIZE PAGE_SIZE
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/* Pipe lock and unlock operations */
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void pipe_lock(struct pipe_inode_info *);
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void pipe_unlock(struct pipe_inode_info *);
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void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
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extern unsigned int pipe_max_size, pipe_min_size;
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int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *);
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/* Drop the inode semaphore and wait for a pipe event, atomically */
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void pipe_wait(struct pipe_inode_info *pipe);
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struct pipe_inode_info *alloc_pipe_info(void);
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void free_pipe_info(struct pipe_inode_info *);
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/* Generic pipe buffer ops functions */
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void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
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int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
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int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
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void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
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extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
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/* for F_SETPIPE_SZ and F_GETPIPE_SZ */
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long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
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struct pipe_inode_info *get_pipe_info(struct file *file);
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int create_pipe_files(struct file **, int);
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#endif
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