5166701b36
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
|
|
#define _LINUX_PIPE_FS_I_H
|
|
|
|
#define PIPE_DEF_BUFFERS 16
|
|
|
|
#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
|
|
#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 */
|
|
|
|
/**
|
|
* struct pipe_buffer - a linux kernel pipe buffer
|
|
* @page: the page containing the data for the pipe buffer
|
|
* @offset: offset of data inside the @page
|
|
* @len: length of data inside the @page
|
|
* @ops: operations associated with this buffer. See @pipe_buf_operations.
|
|
* @flags: pipe buffer flags. See above.
|
|
* @private: private data owned by the ops.
|
|
**/
|
|
struct pipe_buffer {
|
|
struct page *page;
|
|
unsigned int offset, len;
|
|
const struct pipe_buf_operations *ops;
|
|
unsigned int flags;
|
|
unsigned long private;
|
|
};
|
|
|
|
/**
|
|
* struct pipe_inode_info - a linux kernel pipe
|
|
* @mutex: mutex protecting the whole thing
|
|
* @wait: reader/writer wait point in case of empty/full pipe
|
|
* @nrbufs: the number of non-empty pipe buffers in this pipe
|
|
* @buffers: total number of buffers (should be a power of 2)
|
|
* @curbuf: the current pipe buffer entry
|
|
* @tmp_page: cached released page
|
|
* @readers: number of current readers of this pipe
|
|
* @writers: number of current writers of this pipe
|
|
* @files: number of struct file referring this pipe (protected by ->i_lock)
|
|
* @waiting_writers: number of writers blocked waiting for room
|
|
* @r_counter: reader counter
|
|
* @w_counter: writer counter
|
|
* @fasync_readers: reader side fasync
|
|
* @fasync_writers: writer side fasync
|
|
* @bufs: the circular array of pipe buffers
|
|
**/
|
|
struct pipe_inode_info {
|
|
struct mutex mutex;
|
|
wait_queue_head_t wait;
|
|
unsigned int nrbufs, curbuf, buffers;
|
|
unsigned int readers;
|
|
unsigned int writers;
|
|
unsigned int files;
|
|
unsigned int waiting_writers;
|
|
unsigned int r_counter;
|
|
unsigned int w_counter;
|
|
struct page *tmp_page;
|
|
struct fasync_struct *fasync_readers;
|
|
struct fasync_struct *fasync_writers;
|
|
struct pipe_buffer *bufs;
|
|
};
|
|
|
|
/*
|
|
* Note on the nesting of these functions:
|
|
*
|
|
* ->confirm()
|
|
* ->steal()
|
|
* ...
|
|
* ->map()
|
|
* ...
|
|
* ->unmap()
|
|
*
|
|
* That is, ->map() must be called on a confirmed buffer,
|
|
* same goes for ->steal(). See below for the meaning of each
|
|
* operation. Also see kerneldoc in fs/pipe.c for the pipe
|
|
* and generic variants of these hooks.
|
|
*/
|
|
struct pipe_buf_operations {
|
|
/*
|
|
* This is set to 1, if the generic pipe read/write may coalesce
|
|
* data into an existing buffer. If this is set to 0, a new pipe
|
|
* page segment is always used for new data.
|
|
*/
|
|
int can_merge;
|
|
|
|
/*
|
|
* ->confirm() verifies that the data in the pipe buffer is there
|
|
* 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.
|
|
*/
|
|
int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *);
|
|
|
|
/*
|
|
* When the contents of this pipe buffer has been completely
|
|
* consumed by a reader, ->release() is called.
|
|
*/
|
|
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
|
|
|
|
/*
|
|
* Get a reference to the pipe buffer.
|
|
*/
|
|
void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
|
|
};
|
|
|
|
/* 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
|
|
|
|
/* Pipe lock and unlock operations */
|
|
void pipe_lock(struct pipe_inode_info *);
|
|
void pipe_unlock(struct pipe_inode_info *);
|
|
void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
|
|
|
|
extern unsigned int pipe_max_size, pipe_min_size;
|
|
int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *);
|
|
|
|
|
|
/* Drop the inode semaphore and wait for a pipe event, atomically */
|
|
void pipe_wait(struct pipe_inode_info *pipe);
|
|
|
|
struct pipe_inode_info *alloc_pipe_info(void);
|
|
void free_pipe_info(struct pipe_inode_info *);
|
|
|
|
/* Generic pipe buffer ops functions */
|
|
void 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 *);
|
|
void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
|
|
|
|
extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
|
|
|
|
/* for F_SETPIPE_SZ and F_GETPIPE_SZ */
|
|
long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
|
|
struct pipe_inode_info *get_pipe_info(struct file *file);
|
|
|
|
int create_pipe_files(struct file **, int);
|
|
|
|
#endif
|