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-rw-r--r--fs/relayfs/relay.c482
1 files changed, 0 insertions, 482 deletions
diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
deleted file mode 100644
index abf3ceaace49..000000000000
--- a/fs/relayfs/relay.c
+++ /dev/null
@@ -1,482 +0,0 @@
-/*
- * Public API and common code for RelayFS.
- *
- * See Documentation/filesystems/relayfs.txt for an overview of relayfs.
- *
- * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
- * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
- *
- * This file is released under the GPL.
- */
-
-#include <linux/errno.h>
-#include <linux/stddef.h>
-#include <linux/slab.h>
-#include <linux/module.h>
-#include <linux/string.h>
-#include <linux/relayfs_fs.h>
-#include "relay.h"
-#include "buffers.h"
-
-/**
- * relay_buf_empty - boolean, is the channel buffer empty?
- * @buf: channel buffer
- *
- * Returns 1 if the buffer is empty, 0 otherwise.
- */
-int relay_buf_empty(struct rchan_buf *buf)
-{
- return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1;
-}
-
-/**
- * relay_buf_full - boolean, is the channel buffer full?
- * @buf: channel buffer
- *
- * Returns 1 if the buffer is full, 0 otherwise.
- */
-int relay_buf_full(struct rchan_buf *buf)
-{
- size_t ready = buf->subbufs_produced - buf->subbufs_consumed;
- return (ready >= buf->chan->n_subbufs) ? 1 : 0;
-}
-
-/*
- * High-level relayfs kernel API and associated functions.
- */
-
-/*
- * rchan_callback implementations defining default channel behavior. Used
- * in place of corresponding NULL values in client callback struct.
- */
-
-/*
- * subbuf_start() default callback. Does nothing.
- */
-static int subbuf_start_default_callback (struct rchan_buf *buf,
- void *subbuf,
- void *prev_subbuf,
- size_t prev_padding)
-{
- if (relay_buf_full(buf))
- return 0;
-
- return 1;
-}
-
-/*
- * buf_mapped() default callback. Does nothing.
- */
-static void buf_mapped_default_callback(struct rchan_buf *buf,
- struct file *filp)
-{
-}
-
-/*
- * buf_unmapped() default callback. Does nothing.
- */
-static void buf_unmapped_default_callback(struct rchan_buf *buf,
- struct file *filp)
-{
-}
-
-/*
- * create_buf_file_create() default callback. Creates file to represent buf.
- */
-static struct dentry *create_buf_file_default_callback(const char *filename,
- struct dentry *parent,
- int mode,
- struct rchan_buf *buf,
- int *is_global)
-{
- return relayfs_create_file(filename, parent, mode,
- &relay_file_operations, buf);
-}
-
-/*
- * remove_buf_file() default callback. Removes file representing relay buffer.
- */
-static int remove_buf_file_default_callback(struct dentry *dentry)
-{
- return relayfs_remove(dentry);
-}
-
-/* relay channel default callbacks */
-static struct rchan_callbacks default_channel_callbacks = {
- .subbuf_start = subbuf_start_default_callback,
- .buf_mapped = buf_mapped_default_callback,
- .buf_unmapped = buf_unmapped_default_callback,
- .create_buf_file = create_buf_file_default_callback,
- .remove_buf_file = remove_buf_file_default_callback,
-};
-
-/**
- * wakeup_readers - wake up readers waiting on a channel
- * @private: the channel buffer
- *
- * This is the work function used to defer reader waking. The
- * reason waking is deferred is that calling directly from write
- * causes problems if you're writing from say the scheduler.
- */
-static void wakeup_readers(void *private)
-{
- struct rchan_buf *buf = private;
- wake_up_interruptible(&buf->read_wait);
-}
-
-/**
- * __relay_reset - reset a channel buffer
- * @buf: the channel buffer
- * @init: 1 if this is a first-time initialization
- *
- * See relay_reset for description of effect.
- */
-static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
-{
- size_t i;
-
- if (init) {
- init_waitqueue_head(&buf->read_wait);
- kref_init(&buf->kref);
- INIT_WORK(&buf->wake_readers, NULL, NULL);
- } else {
- cancel_delayed_work(&buf->wake_readers);
- flush_scheduled_work();
- }
-
- buf->subbufs_produced = 0;
- buf->subbufs_consumed = 0;
- buf->bytes_consumed = 0;
- buf->finalized = 0;
- buf->data = buf->start;
- buf->offset = 0;
-
- for (i = 0; i < buf->chan->n_subbufs; i++)
- buf->padding[i] = 0;
-
- buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0);
-}
-
-/**
- * relay_reset - reset the channel
- * @chan: the channel
- *
- * This has the effect of erasing all data from all channel buffers
- * and restarting the channel in its initial state. The buffers
- * are not freed, so any mappings are still in effect.
- *
- * NOTE: Care should be taken that the channel isn't actually
- * being used by anything when this call is made.
- */
-void relay_reset(struct rchan *chan)
-{
- unsigned int i;
- struct rchan_buf *prev = NULL;
-
- if (!chan)
- return;
-
- for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i] || chan->buf[i] == prev)
- break;
- __relay_reset(chan->buf[i], 0);
- prev = chan->buf[i];
- }
-}
-
-/**
- * relay_open_buf - create a new channel buffer in relayfs
- *
- * Internal - used by relay_open().
- */
-static struct rchan_buf *relay_open_buf(struct rchan *chan,
- const char *filename,
- struct dentry *parent,
- int *is_global)
-{
- struct rchan_buf *buf;
- struct dentry *dentry;
-
- if (*is_global)
- return chan->buf[0];
-
- buf = relay_create_buf(chan);
- if (!buf)
- return NULL;
-
- /* Create file in fs */
- dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
- buf, is_global);
- if (!dentry) {
- relay_destroy_buf(buf);
- return NULL;
- }
-
- buf->dentry = dentry;
- __relay_reset(buf, 1);
-
- return buf;
-}
-
-/**
- * relay_close_buf - close a channel buffer
- * @buf: channel buffer
- *
- * Marks the buffer finalized and restores the default callbacks.
- * The channel buffer and channel buffer data structure are then freed
- * automatically when the last reference is given up.
- */
-static inline void relay_close_buf(struct rchan_buf *buf)
-{
- buf->finalized = 1;
- buf->chan->cb = &default_channel_callbacks;
- cancel_delayed_work(&buf->wake_readers);
- flush_scheduled_work();
- kref_put(&buf->kref, relay_remove_buf);
-}
-
-static inline void setup_callbacks(struct rchan *chan,
- struct rchan_callbacks *cb)
-{
- if (!cb) {
- chan->cb = &default_channel_callbacks;
- return;
- }
-
- if (!cb->subbuf_start)
- cb->subbuf_start = subbuf_start_default_callback;
- if (!cb->buf_mapped)
- cb->buf_mapped = buf_mapped_default_callback;
- if (!cb->buf_unmapped)
- cb->buf_unmapped = buf_unmapped_default_callback;
- if (!cb->create_buf_file)
- cb->create_buf_file = create_buf_file_default_callback;
- if (!cb->remove_buf_file)
- cb->remove_buf_file = remove_buf_file_default_callback;
- chan->cb = cb;
-}
-
-/**
- * relay_open - create a new relayfs channel
- * @base_filename: base name of files to create
- * @parent: dentry of parent directory, NULL for root directory
- * @subbuf_size: size of sub-buffers
- * @n_subbufs: number of sub-buffers
- * @cb: client callback functions
- *
- * Returns channel pointer if successful, NULL otherwise.
- *
- * Creates a channel buffer for each cpu using the sizes and
- * attributes specified. The created channel buffer files
- * will be named base_filename0...base_filenameN-1. File
- * permissions will be S_IRUSR.
- */
-struct rchan *relay_open(const char *base_filename,
- struct dentry *parent,
- size_t subbuf_size,
- size_t n_subbufs,
- struct rchan_callbacks *cb)
-{
- unsigned int i;
- struct rchan *chan;
- char *tmpname;
- int is_global = 0;
-
- if (!base_filename)
- return NULL;
-
- if (!(subbuf_size && n_subbufs))
- return NULL;
-
- chan = kcalloc(1, sizeof(struct rchan), GFP_KERNEL);
- if (!chan)
- return NULL;
-
- chan->version = RELAYFS_CHANNEL_VERSION;
- chan->n_subbufs = n_subbufs;
- chan->subbuf_size = subbuf_size;
- chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs);
- setup_callbacks(chan, cb);
- kref_init(&chan->kref);
-
- tmpname = kmalloc(NAME_MAX + 1, GFP_KERNEL);
- if (!tmpname)
- goto free_chan;
-
- for_each_online_cpu(i) {
- sprintf(tmpname, "%s%d", base_filename, i);
- chan->buf[i] = relay_open_buf(chan, tmpname, parent,
- &is_global);
- chan->buf[i]->cpu = i;
- if (!chan->buf[i])
- goto free_bufs;
- }
-
- kfree(tmpname);
- return chan;
-
-free_bufs:
- for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i])
- break;
- relay_close_buf(chan->buf[i]);
- if (is_global)
- break;
- }
- kfree(tmpname);
-
-free_chan:
- kref_put(&chan->kref, relay_destroy_channel);
- return NULL;
-}
-
-/**
- * relay_switch_subbuf - switch to a new sub-buffer
- * @buf: channel buffer
- * @length: size of current event
- *
- * Returns either the length passed in or 0 if full.
-
- * Performs sub-buffer-switch tasks such as invoking callbacks,
- * updating padding counts, waking up readers, etc.
- */
-size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
-{
- void *old, *new;
- size_t old_subbuf, new_subbuf;
-
- if (unlikely(length > buf->chan->subbuf_size))
- goto toobig;
-
- if (buf->offset != buf->chan->subbuf_size + 1) {
- buf->prev_padding = buf->chan->subbuf_size - buf->offset;
- old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
- buf->padding[old_subbuf] = buf->prev_padding;
- buf->subbufs_produced++;
- if (waitqueue_active(&buf->read_wait)) {
- PREPARE_WORK(&buf->wake_readers, wakeup_readers, buf);
- schedule_delayed_work(&buf->wake_readers, 1);
- }
- }
-
- old = buf->data;
- new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
- new = buf->start + new_subbuf * buf->chan->subbuf_size;
- buf->offset = 0;
- if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) {
- buf->offset = buf->chan->subbuf_size + 1;
- return 0;
- }
- buf->data = new;
- buf->padding[new_subbuf] = 0;
-
- if (unlikely(length + buf->offset > buf->chan->subbuf_size))
- goto toobig;
-
- return length;
-
-toobig:
- buf->chan->last_toobig = length;
- return 0;
-}
-
-/**
- * relay_subbufs_consumed - update the buffer's sub-buffers-consumed count
- * @chan: the channel
- * @cpu: the cpu associated with the channel buffer to update
- * @subbufs_consumed: number of sub-buffers to add to current buf's count
- *
- * Adds to the channel buffer's consumed sub-buffer count.
- * subbufs_consumed should be the number of sub-buffers newly consumed,
- * not the total consumed.
- *
- * NOTE: kernel clients don't need to call this function if the channel
- * mode is 'overwrite'.
- */
-void relay_subbufs_consumed(struct rchan *chan,
- unsigned int cpu,
- size_t subbufs_consumed)
-{
- struct rchan_buf *buf;
-
- if (!chan)
- return;
-
- if (cpu >= NR_CPUS || !chan->buf[cpu])
- return;
-
- buf = chan->buf[cpu];
- buf->subbufs_consumed += subbufs_consumed;
- if (buf->subbufs_consumed > buf->subbufs_produced)
- buf->subbufs_consumed = buf->subbufs_produced;
-}
-
-/**
- * relay_destroy_channel - free the channel struct
- *
- * Should only be called from kref_put().
- */
-void relay_destroy_channel(struct kref *kref)
-{
- struct rchan *chan = container_of(kref, struct rchan, kref);
- kfree(chan);
-}
-
-/**
- * relay_close - close the channel
- * @chan: the channel
- *
- * Closes all channel buffers and frees the channel.
- */
-void relay_close(struct rchan *chan)
-{
- unsigned int i;
- struct rchan_buf *prev = NULL;
-
- if (!chan)
- return;
-
- for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i] || chan->buf[i] == prev)
- break;
- relay_close_buf(chan->buf[i]);
- prev = chan->buf[i];
- }
-
- if (chan->last_toobig)
- printk(KERN_WARNING "relayfs: one or more items not logged "
- "[item size (%Zd) > sub-buffer size (%Zd)]\n",
- chan->last_toobig, chan->subbuf_size);
-
- kref_put(&chan->kref, relay_destroy_channel);
-}
-
-/**
- * relay_flush - close the channel
- * @chan: the channel
- *
- * Flushes all channel buffers i.e. forces buffer switch.
- */
-void relay_flush(struct rchan *chan)
-{
- unsigned int i;
- struct rchan_buf *prev = NULL;
-
- if (!chan)
- return;
-
- for (i = 0; i < NR_CPUS; i++) {
- if (!chan->buf[i] || chan->buf[i] == prev)
- break;
- relay_switch_subbuf(chan->buf[i], 0);
- prev = chan->buf[i];
- }
-}
-
-EXPORT_SYMBOL_GPL(relay_open);
-EXPORT_SYMBOL_GPL(relay_close);
-EXPORT_SYMBOL_GPL(relay_flush);
-EXPORT_SYMBOL_GPL(relay_reset);
-EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
-EXPORT_SYMBOL_GPL(relay_switch_subbuf);
-EXPORT_SYMBOL_GPL(relay_buf_full);