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relayfs (3/4) (VFS and scheme-specific code)
diff -urpN -X dontdiff linux-2.6.0-test6/fs/Kconfig linux-2.6.0-test6.cur/fs/Kconfig
--- linux-2.6.0-test6/fs/Kconfig Sat Sep 27 19:50:29 2003
+++ linux-2.6.0-test6.cur/fs/Kconfig Tue Oct 7 11:56:19 2003
@@ -892,6 +892,26 @@ config RAMFS
To compile this as a module, choose M here: the module will be called
ramfs.
+config RELAYFS_FS
+ tristate "Relayfs file system support"
+ ---help---
+ Relayfs is a high-speed data relay filesystem designed to provide
+ an efficient mechanism for tools and facilities to relay large
+ amounts of data from kernel space to user space. It's not useful
+ on its own, and should only be enabled if other facilities that
+ need it are enabled, such as for example dynamic printk or the
+ Linux Trace Toolkit.
+
+ See <file:Documentation/filesystems/relayfs.txt> for further
+ information.
+
+ This file system is also available as a module ( = code which can be
+ inserted in and removed from the running kernel whenever you want).
+ The module is called relayfs. If you want to compile it as a
+ module, say M here and read <file:Documentation/modules.txt>.
+
+ If unsure, say N.
+
endmenu
menu "Miscellaneous filesystems"
diff -urpN -X dontdiff linux-2.6.0-test6/fs/Makefile linux-2.6.0-test6.cur/fs/Makefile
--- linux-2.6.0-test6/fs/Makefile Sat Sep 27 19:50:29 2003
+++ linux-2.6.0-test6.cur/fs/Makefile Tue Oct 7 11:54:47 2003
@@ -51,6 +51,7 @@ obj-$(CONFIG_EXT2_FS) += ext2/
obj-$(CONFIG_CRAMFS) += cramfs/
obj-$(CONFIG_RAMFS) += ramfs/
obj-$(CONFIG_HUGETLBFS) += hugetlbfs/
+obj-$(CONFIG_RELAYFS_FS) += relayfs/
obj-$(CONFIG_CODA_FS) += coda/
obj-$(CONFIG_INTERMEZZO_FS) += intermezzo/
obj-$(CONFIG_MINIX_FS) += minix/
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/Makefile linux-2.6.0-test6.cur/fs/relayfs/Makefile
--- linux-2.6.0-test6/fs/relayfs/Makefile Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/Makefile Tue Oct 7 11:52:47 2003
@@ -0,0 +1,7 @@
+#
+# relayfs Makefile
+#
+
+obj-$(CONFIG_RELAYFS_FS) += relayfs.o
+
+relayfs-objs := relay.o relay_lockless.o relay_locking.o inode.o
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/inode.c linux-2.6.0-test6.cur/fs/relayfs/inode.c
--- linux-2.6.0-test6/fs/relayfs/inode.c Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/inode.c Tue Oct 7 11:52:47 2003
@@ -0,0 +1,572 @@
+/*
+ * VFS-related code for RelayFS, a high-speed data relay filesystem.
+ *
+ * Copyright (C) 2003 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
+ * Copyright (C) 2003 - Karim Yaghmour <karim@opersys.com>
+ *
+ * Based on ramfs, Copyright (C) 2002 - Linus Torvalds
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <asm/uaccess.h>
+#include <asm/relay.h>
+
+#define RELAYFS_MAGIC 0x26F82121
+
+static struct super_operations relayfs_ops;
+static struct address_space_operations relayfs_aops;
+static struct inode_operations relayfs_file_inode_operations;
+static struct file_operations relayfs_file_operations;
+static struct inode_operations relayfs_dir_inode_operations;
+
+static struct vfsmount * relayfs_mount;
+static int relayfs_mount_count;
+
+static struct backing_dev_info relayfs_backing_dev_info = {
+ .ra_pages = 0, /* No readahead */
+ .memory_backed = 1, /* Does not contribute to dirty memory */
+};
+
+static struct inode *
+relayfs_get_inode(struct super_block *sb, int mode, dev_t dev)
+{
+ struct inode * inode = new_inode(sb);
+
+ if (inode) {
+ inode->i_mode = mode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_mapping->a_ops = &relayfs_aops;
+ inode->i_mapping->backing_dev_info = &relayfs_backing_dev_info;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ switch (mode & S_IFMT) {
+ default:
+ init_special_inode(inode, mode, dev);
+ break;
+ case S_IFREG:
+ inode->i_op = &relayfs_file_inode_operations;
+ inode->i_fop = &relayfs_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &relayfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inode->i_nlink++;
+ break;
+ case S_IFLNK:
+ inode->i_op = &page_symlink_inode_operations;
+ break;
+ }
+ }
+ return inode;
+}
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+/* SMP-safe */
+static int
+relayfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+{
+ struct inode * inode = relayfs_get_inode(dir->i_sb, mode, dev);
+ int error = -ENOSPC;
+
+ if (inode) {
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
+ error = 0;
+ }
+ return error;
+}
+
+static int
+relayfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+ int retval = relayfs_mknod(dir, dentry, mode | S_IFDIR, 0);
+
+ if (!retval)
+ dir->i_nlink++;
+ return retval;
+}
+
+static int
+relayfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
+{
+
+ return relayfs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+static int
+relayfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
+{
+ struct inode *inode;
+ int error = -ENOSPC;
+
+ inode = relayfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0);
+
+ if (inode) {
+ int l = strlen(symname)+1;
+ error = page_symlink(inode, symname, l);
+ if (!error) {
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ } else
+ iput(inode);
+ }
+ return error;
+}
+
+/**
+ * relayfs_create_entry - create a relayfs directory or file
+ * @name: the name of the file to create
+ * @parent: parent directory
+ * @dentry: result dentry
+ * @entry_type: type of file to create (S_IFREG, S_IFDIR)
+ * @mode: mode
+ * @data: data to associate with the file
+ *
+ * Creates a file or directory with the specifed permissions.
+ */
+static int
+relayfs_create_entry(const char * name, struct dentry * parent, struct dentry **dentry, int entry_type, int mode, void * data)
+{
+ struct qstr qname;
+ struct dentry * d;
+
+ int error = 0;
+
+ error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
+ if (error) {
+ printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
+ return error;
+ }
+
+ qname.name = name;
+ qname.len = strlen(name);
+ qname.hash = full_name_hash(name, qname.len);
+
+ if (parent == NULL)
+ if (relayfs_mount && relayfs_mount->mnt_sb)
+ parent = relayfs_mount->mnt_sb->s_root;
+
+ if (parent == NULL) {
+ simple_release_fs(&relayfs_mount, &relayfs_mount_count);
+ return -EINVAL;
+ }
+
+ parent = dget(parent);
+ down(&parent->d_inode->i_sem);
+ d = lookup_hash(&qname, parent);
+ if (IS_ERR(d)) {
+ error = PTR_ERR(d);
+ goto release_mount;
+ }
+
+ if (d->d_inode) {
+ error = -EEXIST;
+ goto release_mount;
+ }
+
+ if (entry_type == S_IFREG)
+ error = relayfs_create(parent->d_inode, d, entry_type | mode, NULL);
+ else
+ error = relayfs_mkdir(parent->d_inode, d, entry_type | mode);
+
+ if (error)
+ goto release_mount;
+
+ if ((entry_type == S_IFREG) && data) {
+ d->d_inode->u.generic_ip = data;
+ goto exit; /* don't release mount for regular files */
+ }
+
+release_mount:
+ simple_release_fs(&relayfs_mount, &relayfs_mount_count);
+
+exit:
+ *dentry = d;
+ up(&parent->d_inode->i_sem);
+ dput(parent);
+
+ return error;
+}
+
+/**
+ * relayfs_create_file - create a file in the relay filesystem
+ * @name: the name of the file to create
+ * @parent: parent directory
+ * @dentry: result dentry
+ * @data: data to associate with the file
+ *
+ * The file will be created user rwx on behalf of current user.
+ */
+int
+relayfs_create_file(const char * name, struct dentry * parent, struct dentry **dentry, void * data)
+{
+ return relayfs_create_entry(name, parent, dentry, S_IFREG,
+ S_IRUSR | S_IWUSR, data);
+}
+
+/**
+ * relayfs_create_dir - create a directory in the relay filesystem
+ * @name: the name of the directory to create
+ * @parent: parent directory
+ * @dentry: result dentry
+ *
+ * The directory will be created world rwx on behalf of current user.
+ */
+int
+relayfs_create_dir(const char * name, struct dentry * parent, struct dentry **dentry)
+{
+ return relayfs_create_entry(name, parent, dentry, S_IFDIR,
+ S_IRWXU | S_IRUGO | S_IXUGO, NULL);
+}
+
+/**
+ * relayfs_remove_file - remove a file in the relay filesystem
+ * @dentry: file dentry
+ *
+ * Remove a file previously created by relayfs_create_file.
+ */
+int
+relayfs_remove_file(struct dentry *dentry)
+{
+ struct dentry *parent;
+ int is_reg;
+
+ parent = dentry->d_parent;
+ if (parent == NULL)
+ return -EINVAL;
+
+ is_reg = S_ISREG(dentry->d_inode->i_mode);
+
+ parent = dget(parent);
+ down(&parent->d_inode->i_sem);
+ if (dentry->d_inode) {
+ simple_unlink(parent->d_inode, dentry);
+ d_delete(dentry);
+ }
+ dput(dentry);
+ up(&parent->d_inode->i_sem);
+ dput(parent);
+
+ if(is_reg)
+ simple_release_fs(&relayfs_mount, &relayfs_mount_count);
+
+ return 0;
+}
+
+/**
+ * relayfs_open - open file op for relayfs files
+ * @inode: the inode
+ * @filp: the file
+ *
+ * Associates the channel with the file, and increments the
+ * channel refcount. If the file is opened O_EXCL, reads
+ * will be 'auto-consuming'.
+ */
+int
+relayfs_open(struct inode *inode, struct file *filp)
+{
+ struct rchan *rchan;
+ struct rchan_reader *reader;
+ int auto_consume = 0;
+
+ if (inode->u.generic_ip) {
+ if(filp->f_flags & O_EXCL)
+ auto_consume = 1;
+ rchan = (struct rchan *)inode->u.generic_ip;
+ reader = __add_rchan_reader(rchan, filp, auto_consume);
+ if (reader == NULL)
+ return -ENOMEM;
+ filp->private_data = reader;
+ /* Inc relay channel refcount for file */
+ rchan_get(rchan->id);
+ }
+
+ return 0;
+}
+
+/**
+ * relayfs_mmap - mmap file op for relayfs files
+ * @filp: the file
+ * @vma: the vma describing what to map
+ *
+ * Calls upon relay_mmap_buffer to map the file into user space.
+ */
+int
+relayfs_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct rchan *rchan;
+
+ rchan = ((struct rchan_reader *)filp->private_data)->rchan;
+
+ return relay_mmap_buffer(rchan->id, vma);
+}
+
+extern void __relay_bytes_consumed(struct rchan *rchan,
+ u32 bytes_consumed,
+ u32 read_offset);
+
+/**
+ * relayfs_file_read - read file op for relayfs files
+ * @filp: the file
+ * @buf: user buf to read into
+ * @count: bytes requested
+ * @offset: offset into file
+ *
+ * Attempt to read count bytes into buffer. If there are fewer
+ * than count bytes available, return available. if the read would
+ * cross a sub-buffer boundary, this function will only return the
+ * bytes available to the end of the sub-buffer; a subsequent read
+ * would get the remaining bytes (starting from the beginning of the
+ * buffer). Because we're reading from a circular buffer, if the
+ * read would wrap around to sub-buffer 0, offset will be reset
+ * to 0 to mark the beginning of the buffer. If nothing at all
+ * is available, the caller will be put on a wait queue until
+ * there is. This function takes into account the 'unused bytes',
+ * if any, at the end of each sub-buffer, and will transparently
+ * skip over them.
+ */
+ssize_t
+relayfs_file_read(struct file *filp, char * buf, size_t count, loff_t *offset)
+{
+ size_t read_count;
+ struct rchan_reader *reader;
+
+ if (offset != &filp->f_pos) /* pread, seeking not supported */
+ return -ESPIPE;
+
+ if (count == 0)
+ return 0;
+
+ reader = (struct rchan_reader *)filp->private_data;
+ read_count = relay_read(reader, buf, count,
+ filp->f_flags & (O_NDELAY | O_NONBLOCK) ? 0 : 1);
+
+ return read_count;
+}
+
+/**
+ * relayfs_file_write - write file op for relayfs files
+ * @filp: the file
+ * @buf: user buf to write from
+ * @count: bytes to write
+ * @offset: offset into file
+ *
+ * Reserves a slot in the relay buffer and writes count bytes
+ * into it. The current limit for a single write is 2 pages
+ * worth.
+ */
+ssize_t
+relayfs_file_write(struct file *filp, const char *buf, size_t count, loff_t *offset)
+{
+ int write_count;
+ char * write_buf;
+ struct rchan *rchan;
+ int err = 0;
+
+ if (offset != &filp->f_pos) /* pwrite, not supported */
+ return -ESPIPE;
+
+ if (count == 0)
+ return 0;
+
+ rchan = ((struct rchan_reader *)filp->private_data)->rchan;
+
+ /* Change this if need to write more than 2 pages at once */
+ if (count > 2 * PAGE_SIZE)
+ return -EINVAL;
+
+ write_buf = (char *)__get_free_pages(GFP_KERNEL, 1);
+ if (write_buf == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(write_buf, buf, count))
+ return -EFAULT;
+
+ if (filp->f_flags & (O_NDELAY | O_NONBLOCK)) {
+ write_count = relay_write(rchan->id, write_buf, count, -1);
+ if (write_count == 0)
+ return -EAGAIN;
+ } else {
+ err = wait_event_interruptible(rchan->write_wait,
+ (write_count = relay_write(rchan->id, write_buf, count, -1)));
+ if (err)
+ return err;
+ }
+
+ if (write_count > 0)
+ *offset += write_count;
+
+ free_pages((unsigned long)write_buf, 1);
+
+ return write_count;
+}
+
+/**
+ * relayfs_poll - poll file op for relayfs files
+ * @filp: the file
+ * @wait: poll table
+ *
+ * Poll implemention.
+ */
+static unsigned int
+relayfs_poll(struct file *filp, poll_table *wait)
+{
+ struct rchan_reader *reader;
+ unsigned int mask = 0;
+
+ reader = (struct rchan_reader *)filp->private_data;
+
+ if (reader->rchan->finalized)
+ return POLLERR;
+
+ if (filp->f_mode & FMODE_READ) {
+ poll_wait(filp, &reader->rchan->read_wait, wait);
+ if (!rchan_empty(reader))
+ mask |= POLLIN | POLLRDNORM;
+ }
+
+ if (filp->f_mode & FMODE_WRITE) {
+ poll_wait(filp, &reader->rchan->write_wait, wait);
+ if (!rchan_full(reader))
+ mask |= POLLOUT | POLLWRNORM;
+ }
+
+ return mask;
+}
+
+/**
+ * relayfs_release - release file op for relayfs files
+ * @inode: the inode
+ * @filp: the file
+ *
+ * Decrements the channel refcount, as the filesystem is
+ * no longer using it.
+ */
+int
+relayfs_release(struct inode *inode, struct file *filp)
+{
+ struct rchan_reader *reader;
+ int err = 0;
+
+ reader = (struct rchan_reader *)filp->private_data;
+
+ /* The channel is no longer in use as far as this file is concerned */
+ rchan_put(reader->rchan);
+ __remove_rchan_reader(reader);
+
+ return err;
+}
+
+static struct address_space_operations relayfs_aops = {
+ .readpage = simple_readpage,
+ .prepare_write = simple_prepare_write,
+ .commit_write = simple_commit_write
+};
+
+static struct file_operations relayfs_file_operations = {
+ .open = relayfs_open,
+ .read = relayfs_file_read,
+ .write = relayfs_file_write,
+ .poll = relayfs_poll,
+ .mmap = relayfs_mmap,
+ .fsync = simple_sync_file,
+ .release = relayfs_release,
+};
+
+static struct inode_operations relayfs_file_inode_operations = {
+ .getattr = simple_getattr,
+};
+
+static struct inode_operations relayfs_dir_inode_operations = {
+ .create = relayfs_create,
+ .lookup = simple_lookup,
+ .link = simple_link,
+ .unlink = simple_unlink,
+ .symlink = relayfs_symlink,
+ .mkdir = relayfs_mkdir,
+ .rmdir = simple_rmdir,
+ .mknod = relayfs_mknod,
+ .rename = simple_rename,
+};
+
+static struct super_operations relayfs_ops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+};
+
+static int
+relayfs_fill_super(struct super_block * sb, void * data, int silent)
+{
+ struct inode * inode;
+ struct dentry * root;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = RELAYFS_MAGIC;
+ sb->s_op = &relayfs_ops;
+ inode = relayfs_get_inode(sb, S_IFDIR | 0755, 0);
+
+ if (!inode)
+ return -ENOMEM;
+
+ root = d_alloc_root(inode);
+ if (!root) {
+ iput(inode);
+ return -ENOMEM;
+ }
+ sb->s_root = root;
+
+ return 0;
+}
+
+static struct super_block *
+relayfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return get_sb_single(fs_type, flags, data, relayfs_fill_super);
+}
+
+static struct file_system_type relayfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "relayfs",
+ .get_sb = relayfs_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static int __init
+init_relayfs_fs(void)
+{
+ return register_filesystem(&relayfs_fs_type);
+}
+
+static void __exit
+exit_relayfs_fs(void)
+{
+ unregister_filesystem(&relayfs_fs_type);
+}
+
+module_init(init_relayfs_fs)
+module_exit(exit_relayfs_fs)
+
+MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
+MODULE_DESCRIPTION("Relay Filesystem");
+MODULE_LICENSE("GPL");
+
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/relay_locking.c linux-2.6.0-test6.cur/fs/relayfs/relay_locking.c
--- linux-2.6.0-test6/fs/relayfs/relay_locking.c Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/relay_locking.c Tue Oct 7 11:52:47 2003
@@ -0,0 +1,248 @@
+/*
+ * RelayFS locking scheme implementation.
+ *
+ * Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com)
+ * Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
+ *
+ * This file is released under the GPL.
+ */
+
+#include <asm/relay.h>
+#include "relay_locking.h"
+
+/**
+ * switch_buffers - switches between read and write buffers.
+ * @cur_time: current time.
+ * @cur_tsc: the TSC associated with current_time, if applicable
+ * @rchan: the channel
+ * @finalizing: if true, don't start a new buffer
+ *
+ * This should be called from with interrupts disabled.
+ */
+static void
+switch_buffers(struct timeval cur_time,
+ u32 cur_tsc,
+ struct rchan *rchan,
+ int finalizing)
+{
+ char *chan_buf_end;
+
+ int bytes_written;
+
+ bytes_written = rchan->callbacks->buffer_end(rchan->id,
+ cur_write_pos(rchan), write_buf_end(rchan),
+ cur_time, cur_tsc, using_tsc(rchan));
+ if (bytes_written == 0)
+ rchan->unused_bytes[rchan->buf_idx % rchan->n_bufs] =
+ write_buf_end(rchan) - cur_write_pos(rchan);
+
+ chan_buf_end = rchan->buf + rchan->n_bufs * rchan->buf_size;
+ if(write_buf(rchan) + rchan->buf_size >= chan_buf_end)
+ write_buf(rchan) = rchan->buf;
+ else
+ write_buf(rchan) += rchan->buf_size;
+ write_buf_end(rchan) = write_buf(rchan) + rchan->buf_size;
+ write_limit(rchan) = write_buf_end(rchan) - rchan->end_reserve;
+ cur_write_pos(rchan) = write_buf(rchan);
+
+ rchan->buf_start_time = cur_time;
+ rchan->buf_start_tsc = cur_tsc;
+
+ rchan->buf_idx++;
+ rchan->buf_id++;
+ if (!packet_delivery(rchan))
+ rchan->unused_bytes[rchan->buf_idx % rchan->n_bufs] = 0;
+ rchan->bufs_produced++;
+
+ if (!finalizing) {
+ bytes_written = rchan->callbacks->buffer_start(rchan->id, cur_write_pos(rchan), rchan->buf_id, cur_time, cur_tsc, using_tsc(rchan));
+ cur_write_pos(rchan) += bytes_written;
+ }
+}
+
+/**
+ * locking_reserve - reserve a slot in the trace buffer for an event.
+ * @rchan: the channel
+ * @slot_len: the length of the slot to reserve
+ * @ts: variable that will receive the time the slot was reserved
+ * @tsc: the timestamp counter associated with time
+ * @err: receives the result flags
+ * @interrupting: if this write is interrupting another, set to non-zero
+ *
+ * Returns pointer to the beginning of the reserved slot, NULL if error.
+ *
+ * The err value contains the result flags and is an ORed combination
+ * of the following:
+ *
+ * RELAY_BUFFER_SWITCH_NONE - no buffer switch occurred
+ * RELAY_EVENT_DISCARD_NONE - event should not be discarded
+ * RELAY_BUFFER_SWITCH - buffer switch occurred
+ * RELAY_EVENT_DISCARD - event should be discarded (all buffers are full)
+ * RELAY_EVENT_TOO_LONG - event won't fit into even an empty buffer
+ */
+inline char *
+locking_reserve(struct rchan *rchan,
+ u32 slot_len,
+ struct timeval *ts,
+ u32 *tsc,
+ int *err,
+ int *interrupting)
+{
+ u32 buffers_ready;
+ int bytes_written;
+
+ *err = RELAY_BUFFER_SWITCH_NONE;
+
+ if (slot_len >= rchan->buf_size) {
+ *err = RELAY_WRITE_DISCARD | RELAY_WRITE_TOO_LONG;
+ return NULL;
+ }
+
+ if (rchan->initialized == 0) {
+ rchan->initialized = 1;
+ get_timestamp(&rchan->buf_start_time,
+ &rchan->buf_start_tsc, rchan);
+ rchan->unused_bytes[0] = 0;
+ bytes_written = rchan->callbacks->buffer_start(
+ rchan->id, cur_write_pos(rchan),
+ rchan->buf_id, rchan->buf_start_time,
+ rchan->buf_start_tsc, using_tsc(rchan));
+ cur_write_pos(rchan) += bytes_written;
+ *tsc = get_time_delta(ts, rchan);
+ return cur_write_pos(rchan);
+ }
+
+ *tsc = get_time_delta(ts, rchan);
+
+ if (in_progress_event_size(rchan)) {
+ interrupted_pos(rchan) = cur_write_pos(rchan);
+ cur_write_pos(rchan) = in_progress_event_pos(rchan)
+ + in_progress_event_size(rchan)
+ + interrupting_size(rchan);
+ *interrupting = 1;
+ } else {
+ in_progress_event_pos(rchan) = cur_write_pos(rchan);
+ in_progress_event_size(rchan) = slot_len;
+ interrupting_size(rchan) = 0;
+ }
+
+ if (cur_write_pos(rchan) + slot_len > write_limit(rchan)) {
+ if (atomic_read(&rchan->suspended) == 1) {
+ *err = RELAY_WRITE_DISCARD;
+ return NULL;
+ }
+
+ buffers_ready = rchan->bufs_produced - rchan->bufs_consumed;
+ if (buffers_ready == rchan->n_bufs - 1) {
+ if (!mode_continuous(rchan)) {
+ atomic_set(&rchan->suspended, 1);
+ *err = RELAY_WRITE_DISCARD;
+ return NULL;
+ }
+ }
+
+ get_timestamp(ts, tsc, rchan);
+ switch_buffers(*ts, *tsc, rchan, 0);
+ recalc_time_delta(ts, tsc, rchan);
+ *err = RELAY_BUFFER_SWITCH;
+ }
+
+ return cur_write_pos(rchan);
+}
+
+/**
+ * locking_commit - commit a reserved slot in the buffer
+ * @rchan: the channel
+ * @from: commit the length starting here
+ * @len: length committed
+ * @deliver: length committed
+ * @interrupting: not used
+ *
+ * Commits len bytes and calls deliver callback if applicable.
+ */
+inline void
+locking_commit(struct rchan *rchan,
+ char *from,
+ u32 len,
+ int deliver,
+ int interrupting)
+{
+ cur_write_pos(rchan) += len;
+
+ if (interrupting) {
+ cur_write_pos(rchan) = interrupted_pos(rchan);
+ interrupting_size(rchan) += len;
+ } else {
+ in_progress_event_size(rchan) = 0;
+ if (interrupting_size(rchan)) {
+ cur_write_pos(rchan) += interrupting_size(rchan);
+ interrupting_size(rchan) = 0;
+ }
+ }
+
+ if (deliver) {
+ rchan->callbacks->deliver(rchan->id, from, len);
+ resize_check(rchan);
+ }
+}
+
+/**
+ * locking_finalize: - finalize last buffer at end of channel use
+ * @rchan: the channel
+ */
+inline void
+locking_finalize(struct rchan *rchan)
+{
+ unsigned long int flags;
+ struct timeval time;
+ u32 tsc;
+
+ local_irq_save(flags);
+ get_timestamp(&time, &tsc, rchan);
+ switch_buffers(time, tsc, rchan, 1);
+ local_irq_restore(flags);
+}
+
+/**
+ * locking_get_offset - get current and max 'file' offsets for VFS
+ * @rchan: the channel
+ * @max_offset: maximum channel offset
+ *
+ * Returns the current and maximum buffer offsets in VFS terms.
+ */
+u32
+locking_get_offset(struct rchan *rchan,
+ u32 *max_offset)
+{
+ if (max_offset)
+ *max_offset = rchan->buf_size * rchan->n_bufs - 1;
+
+ return cur_write_pos(rchan) - rchan->buf;
+}
+
+/**
+ * locking_reset - reset the channel
+ * @rchan: the channel
+ * @init: 1 if this is a first-time channel initialization
+ */
+void locking_reset(struct rchan *rchan, int init)
+{
+ if (init)
+ channel_lock(rchan) = SPIN_LOCK_UNLOCKED;
+ write_buf(rchan) = rchan->buf;
+ write_buf_end(rchan) = write_buf(rchan) + rchan->buf_size;
+ cur_write_pos(rchan) = write_buf(rchan);
+ write_limit(rchan) = write_buf_end(rchan) - rchan->end_reserve;
+ in_progress_event_pos(rchan) = NULL;
+ in_progress_event_size(rchan) = 0;
+ interrupted_pos(rchan) = NULL;
+ interrupting_size(rchan) = 0;
+}
+
+
+
+
+
+
+
+
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/relay_locking.h linux-2.6.0-test6.cur/fs/relayfs/relay_locking.h
--- linux-2.6.0-test6/fs/relayfs/relay_locking.h Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/relay_locking.h Tue Oct 7 11:52:47 2003
@@ -0,0 +1,32 @@
+#ifndef _RELAY_LOCKING_H
+#define _RELAY_LOCKING_H
+
+extern char *
+locking_reserve(struct rchan *rchan,
+ u32 slot_len,
+ struct timeval *time_stamp,
+ u32 *tsc,
+ int *err,
+ int *interrupting);
+
+extern void
+locking_commit(struct rchan *rchan,
+ char *from,
+ u32 len,
+ int deliver,
+ int interrupting);
+
+extern void
+locking_resume(struct rchan *rchan);
+
+extern void
+locking_finalize(struct rchan *rchan);
+
+extern u32
+locking_get_offset(struct rchan *rchan, u32 *max_offset);
+
+extern void
+locking_reset(struct rchan *rchan,
+ int init);
+
+#endif /* _RELAY_LOCKING_H */
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/relay_lockless.c linux-2.6.0-test6.cur/fs/relayfs/relay_lockless.c
--- linux-2.6.0-test6/fs/relayfs/relay_lockless.c Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/relay_lockless.c Tue Oct 7 11:52:47 2003
@@ -0,0 +1,499 @@
+/*
+ * RelayFS lockless scheme implementation.
+ *
+ * Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com)
+ * Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
+ * Copyright (C) 2002, 2003 - Bob Wisniewski (bob@watson.ibm.com), IBM Corp
+ *
+ * This file is released under the GPL.
+ */
+
+#include <asm/relay.h>
+#include "relay_lockless.h"
+
+/**
+ * compare_and_store_volatile - self-explicit
+ * @ptr: ptr to the word that will receive the new value
+ * @oval: the value we think is currently in *ptr
+ * @nval: the value *ptr will get if we were right
+ */
+inline int
+compare_and_store_volatile(volatile u32 *ptr,
+ u32 oval,
+ u32 nval)
+{
+ u32 prev;
+
+ barrier();
+ prev = cmpxchg(ptr, oval, nval);
+ barrier();
+
+ return (prev == oval);
+}
+
+/**
+ * atomic_set_volatile - atomically set the value in ptr to nval.
+ * @ptr: ptr to the word that will receive the new value
+ * @nval: the new value
+ */
+inline void
+atomic_set_volatile(atomic_t *ptr,
+ u32 nval)
+{
+ barrier();
+ atomic_set(ptr, (int)nval);
+ barrier();
+}
+
+/**
+ * atomic_add_volatile - atomically add val to the value at ptr.
+ * @ptr: ptr to the word that will receive the addition
+ * @val: the value to add to *ptr
+ */
+inline void
+atomic_add_volatile(atomic_t *ptr, u32 val)
+{
+ barrier();
+ atomic_add((int)val, ptr);
+ barrier();
+}
+
+/**
+ * atomic_sub_volatile - atomically substract val from the value at ptr.
+ * @ptr: ptr to the word that will receive the subtraction
+ * @val: the value to subtract from *ptr
+ */
+inline void
+atomic_sub_volatile(atomic_t *ptr, s32 val)
+{
+ barrier();
+ atomic_sub((int)val, ptr);
+ barrier();
+}
+
+/**
+ * lockless_commit - commit a reserved slot in the buffer
+ * @rchan: the channel
+ * @from: commit the length starting here
+ * @len: length committed
+ * @deliver: length committed
+ * @interrupting: not used
+ *
+ * Commits len bytes and calls deliver callback if applicable.
+ */
+inline void
+lockless_commit(struct rchan *rchan,
+ char *from,
+ u32 len,
+ int deliver,
+ int interrupting)
+{
+ u32 bufno, idx;
+
+ idx = from - rchan->buf;
+
+ if (len > 0) {
+ bufno = RELAY_BUFNO_GET(idx, offset_bits(rchan));
+ atomic_add_volatile(&fill_count(rchan, bufno), len);
+ }
+
+ if (deliver) {
+ rchan->callbacks->deliver(rchan->id, from, len);
+ resize_check(rchan);
+ }
+}
+
+/**
+ * get_buffer_end - get the address of the end of buffer
+ * @rchan: the channel
+ * @buf_idx: index into channel corresponding to address
+ */
+static inline char *
+get_buffer_end(struct rchan *rchan, u32 buf_idx)
+{
+ return rchan->buf
+ + RELAY_BUF_OFFSET_CLEAR(buf_idx, offset_mask(rchan))
+ + RELAY_BUF_SIZE(offset_bits(rchan));
+}
+
+/**
+ * finalize_buffer - utility function consolidating end-of-buffer tasks.
+ * @end_idx: index into trace buffer to write the end-buffer event at
+ * @size_lost: number of unused bytes at the end of the buffer
+ * @time_stamp: the time of the end-buffer event
+ * @tsc: the timestamp counter associated with time
+ * @cpu_id: the CPU id associated with the event
+ *
+ * This function must be called with local irqs disabled.
+ */
+static inline void
+finalize_buffer(u32 end_idx,
+ u32 size_lost,
+ struct timeval *time_stamp,
+ u32 *tsc,
+ struct rchan *rchan)
+{
+ char* cur_write_pos;
+ char* write_buf_end;
+ u32 bufno;
+ int bytes_written;
+
+ cur_write_pos = rchan->buf + end_idx;
+ write_buf_end = get_buffer_end(rchan, end_idx - 1);
+
+ bytes_written = rchan->callbacks->buffer_end(rchan->id, cur_write_pos,
+ write_buf_end, *time_stamp, *tsc, using_tsc(rchan));
+ /* We assume that since the client didn't write anything, at some
+ point the unused_bytes value will be needed. */
+ if (bytes_written == 0)
+ rchan->unused_bytes[rchan->buf_idx % rchan->n_bufs] = size_lost;
+
+ bufno = RELAY_BUFNO_GET(end_idx, offset_bits(rchan));
+ atomic_add_volatile(&fill_count(rchan, bufno), size_lost);
+ rchan->bufs_produced++;
+}
+
+/**
+ * lockless_finalize: - finalize last buffer at end of channel use
+ * @rchan: the channel
+ */
+inline void
+lockless_finalize(struct rchan *rchan)
+{
+ u32 event_end_idx;
+ u32 size_lost;
+ unsigned long int flags;
+ struct timeval time;
+ u32 tsc;
+
+ event_end_idx = RELAY_BUF_OFFSET_GET(idx(rchan), offset_mask(rchan));
+ size_lost = RELAY_BUF_SIZE(offset_bits(rchan)) - event_end_idx;
+
+ local_irq_save(flags);
+ get_timestamp(&time, &tsc, rchan);
+ finalize_buffer(idx(rchan) & idx_mask(rchan), size_lost,
+ &time, &tsc, rchan);
+ local_irq_restore(flags);
+}
+
+/**
+ * discard_check: - determine whether a write should be discarded
+ * @rchan: the channel
+ * @old_idx: index into trace buffer where check for space should begin
+ * @write_len: the length of the write to check
+ * @time_stamp: the time of the end-buffer event
+ * @tsc: the timestamp counter associated with time
+ *
+ * The return value contains the result flags and is an ORed combination
+ * of the following:
+ *
+ * RELAY_WRITE_DISCARD_NONE - write should not be discarded
+ * RELAY_BUFFER_SWITCH - buffer switch occurred
+ * RELAY_WRITE_DISCARD - write should be discarded (all buffers are full)
+ * RELAY_WRITE_TOO_LONG - write won't fit into even an empty buffer
+ */
+static inline int
+discard_check(struct rchan *rchan,
+ u32 old_idx,
+ u32 write_len,
+ struct timeval *time_stamp,
+ u32 *tsc)
+{
+ u32 buffers_ready;
+ u32 offset_mask = offset_mask(rchan);
+ u8 offset_bits = offset_bits(rchan);
+ u32 idx_mask = idx_mask(rchan);
+ u32 size_lost;
+ unsigned long int flags;
+
+ if (write_len > RELAY_BUF_SIZE(offset_bits))
+ return RELAY_WRITE_DISCARD | RELAY_WRITE_TOO_LONG;
+
+ if (mode_continuous(rchan))
+ return RELAY_WRITE_DISCARD_NONE;
+
+ local_irq_save(flags);
+
+ if (atomic_read(&rchan->suspended) == 1) {
+ local_irq_restore(flags);
+ return RELAY_WRITE_DISCARD;
+ }
+
+ buffers_ready = rchan->bufs_produced - rchan->bufs_consumed;
+ if (buffers_ready == rchan->n_bufs - 1) {
+ atomic_set(&rchan->suspended, 1);
+ size_lost = RELAY_BUF_SIZE(offset_bits)
+ - RELAY_BUF_OFFSET_GET(old_idx, offset_mask);
+ finalize_buffer(old_idx & idx_mask, size_lost,
+ time_stamp, tsc, rchan);
+
+ local_irq_restore(flags);
+
+ return RELAY_BUFFER_SWITCH | RELAY_WRITE_DISCARD;
+ }
+
+ local_irq_restore(flags);
+
+ return RELAY_WRITE_DISCARD_NONE;
+}
+
+/**
+ * switch_buffers - switch over to a new sub-buffer
+ * @rchan: the channel
+ * @slot_len: the length of the slot needed for the current write
+ * @offset: the offset calculated for the new index
+ * @ts: timestamp
+ * @tsc: the timestamp counter associated with time
+ * @old_idx: the value of the buffer control index when we were called
+ * @old_idx: the new calculated value of the buffer control index
+ */
+static inline void
+switch_buffers(struct rchan *rchan,
+ u32 slot_len,
+ u32 offset,
+ struct timeval *ts,
+ u32 *tsc,
+ u32 new_idx,
+ u32 old_idx)
+{
+ u32 size_lost = rchan->end_reserve;
+ unsigned long int flags;
+ u32 idx_mask = idx_mask(rchan);
+ u8 offset_bits = offset_bits(rchan);
+ char *cur_write_pos;
+ u32 new_buf_no;
+ u32 start_reserve = rchan->start_reserve;
+
+ if (offset > 0)
+ size_lost += slot_len - offset;
+ else
+ old_idx += slot_len;
+
+ local_irq_save(flags);
+ finalize_buffer(old_idx & idx_mask, size_lost,
+ ts, tsc, rchan);
+ rchan->buf_start_time = *ts;
+ rchan->buf_start_tsc = *tsc;
+
+ local_irq_restore(flags);
+
+ cur_write_pos = rchan->buf + RELAY_BUF_OFFSET_CLEAR((new_idx
+ & idx_mask), offset_mask(rchan));
+
+ rchan->buf_idx++;
+ rchan->buf_id++;
+
+ rchan->unused_bytes[rchan->buf_idx % rchan->n_bufs] = 0;
+
+ rchan->callbacks->buffer_start(rchan->id, cur_write_pos,
+ rchan->buf_id, *ts, *tsc, using_tsc(rchan));
+
+ new_buf_no = RELAY_BUFNO_GET(new_idx & idx_mask, offset_bits);
+
+ atomic_sub_volatile(&fill_count(rchan, new_buf_no),
+ RELAY_BUF_SIZE(offset_bits) - start_reserve);
+
+ if (atomic_read(&fill_count(rchan, new_buf_no)) < start_reserve)
+ atomic_set_volatile(&fill_count(rchan, new_buf_no),
+ start_reserve);
+}
+
+/**
+ * lockless_reserve_slow - the slow reserve path in the lockless scheme
+ * @rchan: the channel
+ * @slot_len: the length of the slot to reserve
+ * @ts: variable that will receive the time the slot was reserved
+ * @tsc: the timestamp counter associated with time
+ * @old_idx: the value of the buffer control index when we were called
+ * @err: receives the result flags
+ *
+ * Returns pointer to the beginning of the reserved slot, NULL if error.
+
+ * err values same as for lockless_reserve.
+ */
+static inline char *
+lockless_reserve_slow(struct rchan *rchan,
+ u32 slot_len,
+ struct timeval *ts,
+ u32 *tsc,
+ u32 old_idx,
+ int *err)
+{
+ u32 new_idx, offset;
+ unsigned long int flags;
+ u32 offset_mask = offset_mask(rchan);
+ u32 idx_mask = idx_mask(rchan);
+ u32 start_reserve = rchan->start_reserve;
+ u32 end_reserve = rchan->end_reserve;
+ int discard_event;
+ u32 reserved_idx;
+ char *cur_write_pos;
+ int initializing = 0;
+
+ *err = RELAY_BUFFER_SWITCH_NONE;
+
+ discard_event = discard_check(rchan, old_idx, slot_len, ts, tsc);
+ if (discard_event != RELAY_WRITE_DISCARD_NONE) {
+ *err = discard_event;
+ return NULL;
+ }
+
+ local_irq_save(flags);
+ if (rchan->initialized == 0) {
+ rchan->initialized = initializing = 1;
+ idx(rchan) = rchan->start_reserve + rchan->rchan_start_reserve;
+ }
+ local_irq_restore(flags);
+
+ do {
+ old_idx = idx(rchan);
+ new_idx = old_idx + slot_len;
+
+ offset = RELAY_BUF_OFFSET_GET(new_idx + end_reserve,
+ offset_mask);
+
+ if ((offset < slot_len) && (offset > 0)) {
+ reserved_idx = RELAY_BUF_OFFSET_CLEAR(new_idx
+ + end_reserve, offset_mask) + start_reserve;
+ new_idx = reserved_idx + slot_len;
+ } else if (offset < slot_len) {
+ reserved_idx = old_idx;
+ new_idx = RELAY_BUF_OFFSET_CLEAR(new_idx
+ + end_reserve, offset_mask) + start_reserve;
+ } else
+ reserved_idx = old_idx;
+
+ get_timestamp(ts, tsc, rchan);
+ } while (!compare_and_store_volatile(&idx(rchan), old_idx, new_idx));
+
+ reserved_idx &= idx_mask;
+
+ if (initializing == 1) {
+ cur_write_pos = rchan->buf
+ + RELAY_BUF_OFFSET_CLEAR((old_idx & idx_mask),
+ offset_mask(rchan));
+ rchan->buf_start_time = *ts;
+ rchan->buf_start_tsc = *tsc;
+ rchan->unused_bytes[0] = 0;
+
+ rchan->callbacks->buffer_start(rchan->id, cur_write_pos,
+ rchan->buf_id, *ts, *tsc, using_tsc(rchan));
+ }
+
+ if (offset < slot_len) {
+ switch_buffers(rchan, slot_len, offset, ts, tsc, new_idx,
+ old_idx);
+ *err = RELAY_BUFFER_SWITCH;
+ }
+
+ /* If not using TSC, need to calc time delta */
+ recalc_time_delta(ts, tsc, rchan);
+
+ return rchan->buf + reserved_idx;
+}
+
+/**
+ * lockless_reserve - reserve a slot in the trace buffer for an event.
+ * @rchan: the channel
+ * @slot_len: the length of the slot to reserve
+ * @ts: variable that will receive the time the slot was reserved
+ * @tsc: the timestamp counter associated with time
+ * @err: receives the result flags
+ * @interrupting: not used
+ *
+ * Returns pointer to the beginning of the reserved slot, NULL if error.
+ *
+ * The err value contains the result flags and is an ORed combination
+ * of the following:
+ *
+ * RELAY_BUFFER_SWITCH_NONE - no buffer switch occurred
+ * RELAY_EVENT_DISCARD_NONE - event should not be discarded
+ * RELAY_BUFFER_SWITCH - buffer switch occurred
+ * RELAY_EVENT_DISCARD - event should be discarded (all buffers are full)
+ * RELAY_EVENT_TOO_LONG - event won't fit into even an empty buffer
+ */
+inline char *
+lockless_reserve(struct rchan *rchan,
+ u32 slot_len,
+ struct timeval *ts,
+ u32 *tsc,
+ int *err,
+ int *interrupting)
+{
+ u32 old_idx, new_idx, offset;
+ u32 offset_mask = offset_mask(rchan);
+
+ do {
+ old_idx = idx(rchan);
+ new_idx = old_idx + slot_len;
+
+ offset = RELAY_BUF_OFFSET_GET(new_idx + rchan->end_reserve,
+ offset_mask);
+
+ if (offset < slot_len)
+ return lockless_reserve_slow(rchan, slot_len,
+ ts, tsc, old_idx, err);
+
+ get_time_or_tsc(ts, tsc, rchan);
+ } while (!compare_and_store_volatile(&idx(rchan), old_idx, new_idx));
+
+ /* If not using TSC, need to calc time delta */
+ recalc_time_delta(ts, tsc, rchan);
+
+ *err = RELAY_BUFFER_SWITCH_NONE;
+
+ return rchan->buf + (old_idx & idx_mask(rchan));
+}
+
+/**
+ * lockless_get_offset - get current and max 'file' offsets for VFS
+ * @rchan: the channel
+ * @max_offset: maximum channel offset
+ *
+ * Returns the current and maximum buffer offsets in VFS terms.
+ */
+u32
+lockless_get_offset(struct rchan *rchan,
+ u32 *max_offset)
+{
+ if (max_offset)
+ *max_offset = rchan->buf_size * rchan->n_bufs - 1;
+
+ return idx(rchan) & idx_mask(rchan);
+}
+
+/**
+ * lockless_reset - reset the channel
+ * @rchan: the channel
+ * @init: 1 if this is a first-time channel initialization
+ */
+void lockless_reset(struct rchan *rchan, int init)
+{
+ int i;
+
+ resize_order(rchan) = 0;
+ /* Start first buffer at 0 - (end_reserve + 1) so that it
+ gets initialized via buffer_start callback as well. */
+ idx(rchan) = 0UL - (rchan->end_reserve + 1);
+ idx_mask(rchan) =
+ (1UL << (bufno_bits(rchan) + offset_bits(rchan))) - 1;
+ atomic_set(&fill_count(rchan, 0),
+ (int)rchan->start_reserve +
+ (int)rchan->rchan_start_reserve);
+ for (i = 1; i < rchan->n_bufs; i++)
+ atomic_set(&fill_count(rchan, i),
+ (int)RELAY_BUF_SIZE(offset_bits(rchan)));
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
diff -urpN -X dontdiff linux-2.6.0-test6/fs/relayfs/relay_lockless.h linux-2.6.0-test6.cur/fs/relayfs/relay_lockless.h
--- linux-2.6.0-test6/fs/relayfs/relay_lockless.h Wed Dec 31 18:00:00 1969
+++ linux-2.6.0-test6.cur/fs/relayfs/relay_lockless.h Tue Oct 7 11:52:47 2003
@@ -0,0 +1,32 @@
+#ifndef _RELAY_LOCKLESS_H
+#define _RELAY_LOCKLESS_H
+
+extern char *
+lockless_reserve(struct rchan *rchan,
+ u32 slot_len,
+ struct timeval *time_stamp,
+ u32 *tsc,
+ int * interrupting,
+ int * errcode);
+
+extern void
+lockless_commit(struct rchan *rchan,
+ char * from,
+ u32 len,
+ int deliver,
+ int interrupting);
+
+extern void
+lockless_resume(struct rchan *rchan);
+
+extern void
+lockless_finalize(struct rchan *rchan);
+
+extern u32
+lockless_get_offset(struct rchan *rchan, u32 *max_offset);
+
+extern void
+lockless_reset(struct rchan *rchan,
+ int init);
+
+#endif/* _RELAY_LOCKLESS_H */
--
Regards,
Tom Zanussi <zanussi@us.ibm.com>
IBM Linux Technology Center/RAS
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