diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/relayfs_fs.h | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/include/linux/relayfs_fs.h b/include/linux/relayfs_fs.h deleted file mode 100644 index 7342e66247f..00000000000 --- a/include/linux/relayfs_fs.h +++ /dev/null @@ -1,287 +0,0 @@ -/* - * linux/include/linux/relayfs_fs.h - * - * Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp - * Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com) - * - * RelayFS definitions and declarations - */ - -#ifndef _LINUX_RELAYFS_FS_H -#define _LINUX_RELAYFS_FS_H - -#include <linux/config.h> -#include <linux/types.h> -#include <linux/sched.h> -#include <linux/wait.h> -#include <linux/list.h> -#include <linux/fs.h> -#include <linux/poll.h> -#include <linux/kref.h> - -/* - * Tracks changes to rchan/rchan_buf structs - */ -#define RELAYFS_CHANNEL_VERSION 6 - -/* - * Per-cpu relay channel buffer - */ -struct rchan_buf -{ - void *start; /* start of channel buffer */ - void *data; /* start of current sub-buffer */ - size_t offset; /* current offset into sub-buffer */ - size_t subbufs_produced; /* count of sub-buffers produced */ - size_t subbufs_consumed; /* count of sub-buffers consumed */ - struct rchan *chan; /* associated channel */ - wait_queue_head_t read_wait; /* reader wait queue */ - struct work_struct wake_readers; /* reader wake-up work struct */ - struct dentry *dentry; /* channel file dentry */ - struct kref kref; /* channel buffer refcount */ - struct page **page_array; /* array of current buffer pages */ - unsigned int page_count; /* number of current buffer pages */ - unsigned int finalized; /* buffer has been finalized */ - size_t *padding; /* padding counts per sub-buffer */ - size_t prev_padding; /* temporary variable */ - size_t bytes_consumed; /* bytes consumed in cur read subbuf */ - unsigned int cpu; /* this buf's cpu */ -} ____cacheline_aligned; - -/* - * Relay channel data structure - */ -struct rchan -{ - u32 version; /* the version of this struct */ - size_t subbuf_size; /* sub-buffer size */ - size_t n_subbufs; /* number of sub-buffers per buffer */ - size_t alloc_size; /* total buffer size allocated */ - struct rchan_callbacks *cb; /* client callbacks */ - struct kref kref; /* channel refcount */ - void *private_data; /* for user-defined data */ - size_t last_toobig; /* tried to log event > subbuf size */ - struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */ -}; - -/* - * Relay channel client callbacks - */ -struct rchan_callbacks -{ - /* - * subbuf_start - called on buffer-switch to a new sub-buffer - * @buf: the channel buffer containing the new sub-buffer - * @subbuf: the start of the new sub-buffer - * @prev_subbuf: the start of the previous sub-buffer - * @prev_padding: unused space at the end of previous sub-buffer - * - * The client should return 1 to continue logging, 0 to stop - * logging. - * - * NOTE: subbuf_start will also be invoked when the buffer is - * created, so that the first sub-buffer can be initialized - * if necessary. In this case, prev_subbuf will be NULL. - * - * NOTE: the client can reserve bytes at the beginning of the new - * sub-buffer by calling subbuf_start_reserve() in this callback. - */ - int (*subbuf_start) (struct rchan_buf *buf, - void *subbuf, - void *prev_subbuf, - size_t prev_padding); - - /* - * buf_mapped - relayfs buffer mmap notification - * @buf: the channel buffer - * @filp: relayfs file pointer - * - * Called when a relayfs file is successfully mmapped - */ - void (*buf_mapped)(struct rchan_buf *buf, - struct file *filp); - - /* - * buf_unmapped - relayfs buffer unmap notification - * @buf: the channel buffer - * @filp: relayfs file pointer - * - * Called when a relayfs file is successfully unmapped - */ - void (*buf_unmapped)(struct rchan_buf *buf, - struct file *filp); - /* - * create_buf_file - create file to represent a relayfs channel buffer - * @filename: the name of the file to create - * @parent: the parent of the file to create - * @mode: the mode of the file to create - * @buf: the channel buffer - * @is_global: outparam - set non-zero if the buffer should be global - * - * Called during relay_open(), once for each per-cpu buffer, - * to allow the client to create a file to be used to - * represent the corresponding channel buffer. If the file is - * created outside of relayfs, the parent must also exist in - * that filesystem. - * - * The callback should return the dentry of the file created - * to represent the relay buffer. - * - * Setting the is_global outparam to a non-zero value will - * cause relay_open() to create a single global buffer rather - * than the default set of per-cpu buffers. - * - * See Documentation/filesystems/relayfs.txt for more info. - */ - struct dentry *(*create_buf_file)(const char *filename, - struct dentry *parent, - int mode, - struct rchan_buf *buf, - int *is_global); - - /* - * remove_buf_file - remove file representing a relayfs channel buffer - * @dentry: the dentry of the file to remove - * - * Called during relay_close(), once for each per-cpu buffer, - * to allow the client to remove a file used to represent a - * channel buffer. - * - * The callback should return 0 if successful, negative if not. - */ - int (*remove_buf_file)(struct dentry *dentry); -}; - -/* - * relayfs kernel API, fs/relayfs/relay.c - */ - -struct rchan *relay_open(const char *base_filename, - struct dentry *parent, - size_t subbuf_size, - size_t n_subbufs, - struct rchan_callbacks *cb); -extern void relay_close(struct rchan *chan); -extern void relay_flush(struct rchan *chan); -extern void relay_subbufs_consumed(struct rchan *chan, - unsigned int cpu, - size_t consumed); -extern void relay_reset(struct rchan *chan); -extern int relay_buf_full(struct rchan_buf *buf); - -extern size_t relay_switch_subbuf(struct rchan_buf *buf, - size_t length); -extern struct dentry *relayfs_create_dir(const char *name, - struct dentry *parent); -extern int relayfs_remove_dir(struct dentry *dentry); -extern struct dentry *relayfs_create_file(const char *name, - struct dentry *parent, - int mode, - struct file_operations *fops, - void *data); -extern int relayfs_remove_file(struct dentry *dentry); - -/** - * relay_write - write data into the channel - * @chan: relay channel - * @data: data to be written - * @length: number of bytes to write - * - * Writes data into the current cpu's channel buffer. - * - * Protects the buffer by disabling interrupts. Use this - * if you might be logging from interrupt context. Try - * __relay_write() if you know you won't be logging from - * interrupt context. - */ -static inline void relay_write(struct rchan *chan, - const void *data, - size_t length) -{ - unsigned long flags; - struct rchan_buf *buf; - - local_irq_save(flags); - buf = chan->buf[smp_processor_id()]; - if (unlikely(buf->offset + length > chan->subbuf_size)) - length = relay_switch_subbuf(buf, length); - memcpy(buf->data + buf->offset, data, length); - buf->offset += length; - local_irq_restore(flags); -} - -/** - * __relay_write - write data into the channel - * @chan: relay channel - * @data: data to be written - * @length: number of bytes to write - * - * Writes data into the current cpu's channel buffer. - * - * Protects the buffer by disabling preemption. Use - * relay_write() if you might be logging from interrupt - * context. - */ -static inline void __relay_write(struct rchan *chan, - const void *data, - size_t length) -{ - struct rchan_buf *buf; - - buf = chan->buf[get_cpu()]; - if (unlikely(buf->offset + length > buf->chan->subbuf_size)) - length = relay_switch_subbuf(buf, length); - memcpy(buf->data + buf->offset, data, length); - buf->offset += length; - put_cpu(); -} - -/** - * relay_reserve - reserve slot in channel buffer - * @chan: relay channel - * @length: number of bytes to reserve - * - * Returns pointer to reserved slot, NULL if full. - * - * Reserves a slot in the current cpu's channel buffer. - * Does not protect the buffer at all - caller must provide - * appropriate synchronization. - */ -static inline void *relay_reserve(struct rchan *chan, size_t length) -{ - void *reserved; - struct rchan_buf *buf = chan->buf[smp_processor_id()]; - - if (unlikely(buf->offset + length > buf->chan->subbuf_size)) { - length = relay_switch_subbuf(buf, length); - if (!length) - return NULL; - } - reserved = buf->data + buf->offset; - buf->offset += length; - - return reserved; -} - -/** - * subbuf_start_reserve - reserve bytes at the start of a sub-buffer - * @buf: relay channel buffer - * @length: number of bytes to reserve - * - * Helper function used to reserve bytes at the beginning of - * a sub-buffer in the subbuf_start() callback. - */ -static inline void subbuf_start_reserve(struct rchan_buf *buf, - size_t length) -{ - BUG_ON(length >= buf->chan->subbuf_size - 1); - buf->offset = length; -} - -/* - * exported relay file operations, fs/relayfs/inode.c - */ -extern struct file_operations relay_file_operations; - -#endif /* _LINUX_RELAYFS_FS_H */ - |