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/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
*
* ringbuffer/vfs.h
*
* Wait-free ring buffer VFS file operations.
*
* Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#ifndef _LIB_RING_BUFFER_VFS_H
#define _LIB_RING_BUFFER_VFS_H
#include <linux/fs.h>
#include <linux/poll.h>
/* VFS API */
extern const struct file_operations lib_ring_buffer_file_operations;
/*
* Internal file operations.
*/
struct lttng_kernel_ring_buffer;
int lib_ring_buffer_open(struct inode *inode, struct file *file,
struct lttng_kernel_ring_buffer *buf);
int lib_ring_buffer_release(struct inode *inode, struct file *file,
struct lttng_kernel_ring_buffer *buf);
unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait,
struct lttng_kernel_ring_buffer *buf);
ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags, struct lttng_kernel_ring_buffer *buf);
int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma,
struct lttng_kernel_ring_buffer *buf);
/* Ring Buffer ioctl() and ioctl numbers */
long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg, struct lttng_kernel_ring_buffer *buf);
#ifdef CONFIG_COMPAT
long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg, struct lttng_kernel_ring_buffer *buf);
#endif
ssize_t vfs_lib_ring_buffer_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len, unsigned int flags);
loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset,
int origin);
int vfs_lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma);
ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags);
/*
* Use LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF / LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF to read and
* consume sub-buffers sequentially.
*
* Reading sub-buffers without consuming them can be performed with:
*
* LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT
* LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_GET_CONSUMED
* LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_GET_PRODUCED
*
* to get the offset range to consume, and then by passing each sub-buffer
* offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it
* with RING_BUFFER_PUT_SUBBUF.
*
* Note that the "snapshot" API can be used to read the sub-buffer in reverse
* order, which is useful for flight recorder snapshots.
*/
/* Get a snapshot of the current ring buffer producer and consumer positions */
#define LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT _IO(0xF6, 0x00)
/* Get the consumer position (iteration start) */
#define LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_GET_CONSUMED _IOR(0xF6, 0x01, unsigned long)
/* Get the producer position (iteration end) */
#define LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_GET_PRODUCED _IOR(0xF6, 0x02, unsigned long)
/* Get exclusive read access to the specified sub-buffer position */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF _IOW(0xF6, 0x03, unsigned long)
/* Release exclusive sub-buffer access */
#define LTTNG_KERNEL_ABI_RING_BUFFER_PUT_SUBBUF _IO(0xF6, 0x04)
/* Get exclusive read access to the next sub-buffer that can be read. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF _IO(0xF6, 0x05)
/* Release exclusive sub-buffer access, move consumer forward. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF _IO(0xF6, 0x06)
/* returns the size of the current sub-buffer, without padding (for mmap). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, unsigned long)
/* returns the size of the current sub-buffer, with padding (for splice). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_PADDED_SUBBUF_SIZE _IOR(0xF6, 0x08, unsigned long)
/* returns the maximum size for sub-buffers. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, unsigned long)
/* returns the length to mmap. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_MMAP_LEN _IOR(0xF6, 0x0A, unsigned long)
/* returns the offset of the subbuffer belonging to the mmap reader. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, unsigned long)
/* Flush the current sub-buffer, if non-empty. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH _IO(0xF6, 0x0C)
/* Get the current version of the metadata cache (after a get_next). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION _IOR(0xF6, 0x0D, uint64_t)
/*
* Get a snapshot of the current ring buffer producer and consumer positions,
* regardless of whether or not the two positions are contained within the same
* sub-buffer.
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS _IO(0xF6, 0x0E)
/* Flush the current sub-buffer, even if empty. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY _IO(0xF6, 0x0F)
/*
* Reset the position of what has been consumed from the metadata cache to 0
* so it can be read again.
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP _IO(0xF6, 0x10)
/* Clear ring buffer content. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_CLEAR _IO(0xF6, 0x11)
/*
* Get next metadata subbuffer, returning a flag indicating whether the
* metadata is guaranteed to be in a consistent state at the end of this
* sub-buffer (can be parsed).
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK _IOR(0xF6, 0x12, uint32_t)
/*
* Flush the current sub-buffer or populate a packet.
*
* Argument is a pointer to a struct lttng_kernel_abi_ring_buffer_packet_flush_or_populate_packet_args
* which uses the fields as input and output. The region of memory pointed
* at by the `packet` member should be at least large enough to fit
* a sub-buffer for the stream.
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_OR_POPULATE_PACKET _IOWR(0xF6, 0x13, \
struct lttng_kernel_abi_ring_buffer_packet_flush_or_populate_packet_args)
#ifdef CONFIG_COMPAT
/* Get a snapshot of the current ring buffer producer and consumer positions */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_SNAPSHOT LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT
/* Get the consumer position (iteration start) */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED \
_IOR(0xF6, 0x01, compat_ulong_t)
/* Get the producer position (iteration end) */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED \
_IOR(0xF6, 0x02, compat_ulong_t)
/* Get exclusive read access to the specified sub-buffer position */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_SUBBUF _IOW(0xF6, 0x03, compat_ulong_t)
/* Release exclusive sub-buffer access */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_PUT_SUBBUF LTTNG_KERNEL_ABI_RING_BUFFER_PUT_SUBBUF
/* Get exclusive read access to the next sub-buffer that can be read. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_NEXT_SUBBUF LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF
/* Release exclusive sub-buffer access, move consumer forward. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF
/* returns the size of the current sub-buffer, without padding (for mmap). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, compat_ulong_t)
/* returns the size of the current sub-buffer, with padding (for splice). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE \
_IOR(0xF6, 0x08, compat_ulong_t)
/* returns the maximum size for sub-buffers. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, compat_ulong_t)
/* returns the length to mmap. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_MMAP_LEN _IOR(0xF6, 0x0A, compat_ulong_t)
/* returns the offset of the subbuffer belonging to the mmap reader. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, compat_ulong_t)
/* Flush the current sub-buffer, if non-empty. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_FLUSH LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH
/* Get the current version of the metadata cache (after a get_next). */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_METADATA_VERSION LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION
/*
* Get a snapshot of the current ring buffer producer and consumer positions,
* regardless of whether or not the two positions are contained within the same
* sub-buffer.
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS \
LTTNG_KERNEL_ABI_RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS
/* Flush the current sub-buffer, even if empty. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_FLUSH_EMPTY \
LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY
/* Clear ring buffer content. */
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_CLEAR \
LTTNG_KERNEL_ABI_RING_BUFFER_CLEAR
/*
* Get next metadata subbuffer, returning a flag indicating whether the
* metadata is guaranteed to be in a consistent state at the end of this
* sub-buffer (can be parsed).
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_NEXT_SUBBUF_METADATA_CHECK \
LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK
/*
* Flush the current sub-buffer or populate a packet.
*
* Argument is a pointer to a struct lttng_kernel_abi_ring_buffer_packet_flush_or_populate_packet_args
* which uses the fields as input and output. The region of memory pointed
* at by the `packet` member should be at least large enough to fit
* a sub-buffer for the stream.
*/
#define LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_FLUSH_OR_POPULATE_PACKET LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_OR_POPULATE_PACKET
#endif /* CONFIG_COMPAT */
#endif /* _LIB_LTTNG_KERNEL_ABI_RING_BUFFER_VFS_H */
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