diff options
Diffstat (limited to 'fs/relayfs/inode.c')
-rw-r--r-- | fs/relayfs/inode.c | 581 |
1 files changed, 0 insertions, 581 deletions
diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c deleted file mode 100644 index 3835230..0000000 --- a/fs/relayfs/inode.c +++ /dev/null @@ -1,581 +0,0 @@ -/* - * VFS-related code for RelayFS, a high-speed data relay filesystem. - * - * Copyright (C) 2003-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp - * Copyright (C) 2003-2005 - 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/init.h> -#include <linux/string.h> -#include <linux/backing-dev.h> -#include <linux/namei.h> -#include <linux/poll.h> -#include <linux/relayfs_fs.h> -#include "relay.h" -#include "buffers.h" - -#define RELAYFS_MAGIC 0xF0B4A981 - -static struct vfsmount * relayfs_mount; -static int relayfs_mount_count; - -static struct backing_dev_info relayfs_backing_dev_info = { - .ra_pages = 0, /* No readahead */ - .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, -}; - -static struct inode *relayfs_get_inode(struct super_block *sb, - int mode, - struct file_operations *fops, - void *data) -{ - struct inode *inode; - - inode = new_inode(sb); - if (!inode) - return NULL; - - inode->i_mode = mode; - inode->i_uid = 0; - inode->i_gid = 0; - inode->i_blksize = PAGE_CACHE_SIZE; - inode->i_blocks = 0; - 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) { - case S_IFREG: - inode->i_fop = fops; - if (data) - inode->u.generic_ip = data; - break; - case S_IFDIR: - inode->i_op = &simple_dir_inode_operations; - inode->i_fop = &simple_dir_operations; - - /* directory inodes start off with i_nlink == 2 (for "." entry) */ - inode->i_nlink++; - break; - default: - break; - } - - return inode; -} - -/** - * relayfs_create_entry - create a relayfs directory or file - * @name: the name of the file to create - * @parent: parent directory - * @mode: mode - * @fops: file operations to use for the file - * @data: user-associated data for this file - * - * Returns the new dentry, NULL on failure - * - * Creates a file or directory with the specifed permissions. - */ -static struct dentry *relayfs_create_entry(const char *name, - struct dentry *parent, - int mode, - struct file_operations *fops, - void *data) -{ - struct dentry *d; - struct inode *inode; - int error = 0; - - BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode))); - - error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count); - if (error) { - printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error); - return NULL; - } - - if (!parent && relayfs_mount && relayfs_mount->mnt_sb) - parent = relayfs_mount->mnt_sb->s_root; - - if (!parent) { - simple_release_fs(&relayfs_mount, &relayfs_mount_count); - return NULL; - } - - parent = dget(parent); - mutex_lock(&parent->d_inode->i_mutex); - d = lookup_one_len(name, parent, strlen(name)); - if (IS_ERR(d)) { - d = NULL; - goto release_mount; - } - - if (d->d_inode) { - d = NULL; - goto release_mount; - } - - inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data); - if (!inode) { - d = NULL; - goto release_mount; - } - - d_instantiate(d, inode); - dget(d); /* Extra count - pin the dentry in core */ - - if (S_ISDIR(mode)) - parent->d_inode->i_nlink++; - - goto exit; - -release_mount: - simple_release_fs(&relayfs_mount, &relayfs_mount_count); - -exit: - mutex_unlock(&parent->d_inode->i_mutex); - dput(parent); - return d; -} - -/** - * relayfs_create_file - create a file in the relay filesystem - * @name: the name of the file to create - * @parent: parent directory - * @mode: mode, if not specied the default perms are used - * @fops: file operations to use for the file - * @data: user-associated data for this file - * - * Returns file dentry if successful, NULL otherwise. - * - * The file will be created user r on behalf of current user. - */ -struct dentry *relayfs_create_file(const char *name, - struct dentry *parent, - int mode, - struct file_operations *fops, - void *data) -{ - BUG_ON(!fops); - - if (!mode) - mode = S_IRUSR; - mode = (mode & S_IALLUGO) | S_IFREG; - - return relayfs_create_entry(name, parent, mode, fops, data); -} - -/** - * relayfs_create_dir - create a directory in the relay filesystem - * @name: the name of the directory to create - * @parent: parent directory, NULL if parent should be fs root - * - * Returns directory dentry if successful, NULL otherwise. - * - * The directory will be created world rwx on behalf of current user. - */ -struct dentry *relayfs_create_dir(const char *name, struct dentry *parent) -{ - int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; - return relayfs_create_entry(name, parent, mode, NULL, NULL); -} - -/** - * relayfs_remove - remove a file or directory in the relay filesystem - * @dentry: file or directory dentry - * - * Returns 0 if successful, negative otherwise. - */ -int relayfs_remove(struct dentry *dentry) -{ - struct dentry *parent; - int error = 0; - - if (!dentry) - return -EINVAL; - parent = dentry->d_parent; - if (!parent) - return -EINVAL; - - parent = dget(parent); - mutex_lock(&parent->d_inode->i_mutex); - if (dentry->d_inode) { - if (S_ISDIR(dentry->d_inode->i_mode)) - error = simple_rmdir(parent->d_inode, dentry); - else - error = simple_unlink(parent->d_inode, dentry); - if (!error) - d_delete(dentry); - } - if (!error) - dput(dentry); - mutex_unlock(&parent->d_inode->i_mutex); - dput(parent); - - if (!error) - simple_release_fs(&relayfs_mount, &relayfs_mount_count); - - return error; -} - -/** - * relayfs_remove_file - remove a file from relay filesystem - * @dentry: directory dentry - * - * Returns 0 if successful, negative otherwise. - */ -int relayfs_remove_file(struct dentry *dentry) -{ - return relayfs_remove(dentry); -} - -/** - * relayfs_remove_dir - remove a directory in the relay filesystem - * @dentry: directory dentry - * - * Returns 0 if successful, negative otherwise. - */ -int relayfs_remove_dir(struct dentry *dentry) -{ - return relayfs_remove(dentry); -} - -/** - * relay_file_open - open file op for relay files - * @inode: the inode - * @filp: the file - * - * Increments the channel buffer refcount. - */ -static int relay_file_open(struct inode *inode, struct file *filp) -{ - struct rchan_buf *buf = inode->u.generic_ip; - kref_get(&buf->kref); - filp->private_data = buf; - - return 0; -} - -/** - * relay_file_mmap - mmap file op for relay files - * @filp: the file - * @vma: the vma describing what to map - * - * Calls upon relay_mmap_buf to map the file into user space. - */ -static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma) -{ - struct rchan_buf *buf = filp->private_data; - return relay_mmap_buf(buf, vma); -} - -/** - * relay_file_poll - poll file op for relay files - * @filp: the file - * @wait: poll table - * - * Poll implemention. - */ -static unsigned int relay_file_poll(struct file *filp, poll_table *wait) -{ - unsigned int mask = 0; - struct rchan_buf *buf = filp->private_data; - - if (buf->finalized) - return POLLERR; - - if (filp->f_mode & FMODE_READ) { - poll_wait(filp, &buf->read_wait, wait); - if (!relay_buf_empty(buf)) - mask |= POLLIN | POLLRDNORM; - } - - return mask; -} - -/** - * relay_file_release - release file op for relay files - * @inode: the inode - * @filp: the file - * - * Decrements the channel refcount, as the filesystem is - * no longer using it. - */ -static int relay_file_release(struct inode *inode, struct file *filp) -{ - struct rchan_buf *buf = filp->private_data; - kref_put(&buf->kref, relay_remove_buf); - - return 0; -} - -/** - * relay_file_read_consume - update the consumed count for the buffer - */ -static void relay_file_read_consume(struct rchan_buf *buf, - size_t read_pos, - size_t bytes_consumed) -{ - size_t subbuf_size = buf->chan->subbuf_size; - size_t n_subbufs = buf->chan->n_subbufs; - size_t read_subbuf; - - if (buf->bytes_consumed + bytes_consumed > subbuf_size) { - relay_subbufs_consumed(buf->chan, buf->cpu, 1); - buf->bytes_consumed = 0; - } - - buf->bytes_consumed += bytes_consumed; - read_subbuf = read_pos / buf->chan->subbuf_size; - if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) { - if ((read_subbuf == buf->subbufs_produced % n_subbufs) && - (buf->offset == subbuf_size)) - return; - relay_subbufs_consumed(buf->chan, buf->cpu, 1); - buf->bytes_consumed = 0; - } -} - -/** - * relay_file_read_avail - boolean, are there unconsumed bytes available? - */ -static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) -{ - size_t bytes_produced, bytes_consumed, write_offset; - size_t subbuf_size = buf->chan->subbuf_size; - size_t n_subbufs = buf->chan->n_subbufs; - size_t produced = buf->subbufs_produced % n_subbufs; - size_t consumed = buf->subbufs_consumed % n_subbufs; - - write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset; - - if (consumed > produced) { - if ((produced > n_subbufs) && - (produced + n_subbufs - consumed <= n_subbufs)) - produced += n_subbufs; - } else if (consumed == produced) { - if (buf->offset > subbuf_size) { - produced += n_subbufs; - if (buf->subbufs_produced == buf->subbufs_consumed) - consumed += n_subbufs; - } - } - - if (buf->offset > subbuf_size) - bytes_produced = (produced - 1) * subbuf_size + write_offset; - else - bytes_produced = produced * subbuf_size + write_offset; - bytes_consumed = consumed * subbuf_size + buf->bytes_consumed; - - if (bytes_produced == bytes_consumed) - return 0; - - relay_file_read_consume(buf, read_pos, 0); - - return 1; -} - -/** - * relay_file_read_subbuf_avail - return bytes available in sub-buffer - */ -static size_t relay_file_read_subbuf_avail(size_t read_pos, - struct rchan_buf *buf) -{ - size_t padding, avail = 0; - size_t read_subbuf, read_offset, write_subbuf, write_offset; - size_t subbuf_size = buf->chan->subbuf_size; - - write_subbuf = (buf->data - buf->start) / subbuf_size; - write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset; - read_subbuf = read_pos / subbuf_size; - read_offset = read_pos % subbuf_size; - padding = buf->padding[read_subbuf]; - - if (read_subbuf == write_subbuf) { - if (read_offset + padding < write_offset) - avail = write_offset - (read_offset + padding); - } else - avail = (subbuf_size - padding) - read_offset; - - return avail; -} - -/** - * relay_file_read_start_pos - find the first available byte to read - * - * If the read_pos is in the middle of padding, return the - * position of the first actually available byte, otherwise - * return the original value. - */ -static size_t relay_file_read_start_pos(size_t read_pos, - struct rchan_buf *buf) -{ - size_t read_subbuf, padding, padding_start, padding_end; - size_t subbuf_size = buf->chan->subbuf_size; - size_t n_subbufs = buf->chan->n_subbufs; - - read_subbuf = read_pos / subbuf_size; - padding = buf->padding[read_subbuf]; - padding_start = (read_subbuf + 1) * subbuf_size - padding; - padding_end = (read_subbuf + 1) * subbuf_size; - if (read_pos >= padding_start && read_pos < padding_end) { - read_subbuf = (read_subbuf + 1) % n_subbufs; - read_pos = read_subbuf * subbuf_size; - } - - return read_pos; -} - -/** - * relay_file_read_end_pos - return the new read position - */ -static size_t relay_file_read_end_pos(struct rchan_buf *buf, - size_t read_pos, - size_t count) -{ - size_t read_subbuf, padding, end_pos; - size_t subbuf_size = buf->chan->subbuf_size; - size_t n_subbufs = buf->chan->n_subbufs; - - read_subbuf = read_pos / subbuf_size; - padding = buf->padding[read_subbuf]; - if (read_pos % subbuf_size + count + padding == subbuf_size) - end_pos = (read_subbuf + 1) * subbuf_size; - else - end_pos = read_pos + count; - if (end_pos >= subbuf_size * n_subbufs) - end_pos = 0; - - return end_pos; -} - -/** - * relay_file_read - read file op for relay files - * @filp: the file - * @buffer: the userspace buffer - * @count: number of bytes to read - * @ppos: position to read from - * - * Reads count bytes or the number of bytes available in the - * current sub-buffer being read, whichever is smaller. - */ -static ssize_t relay_file_read(struct file *filp, - char __user *buffer, - size_t count, - loff_t *ppos) -{ - struct rchan_buf *buf = filp->private_data; - struct inode *inode = filp->f_dentry->d_inode; - size_t read_start, avail; - ssize_t ret = 0; - void *from; - - mutex_lock(&inode->i_mutex); - if(!relay_file_read_avail(buf, *ppos)) - goto out; - - read_start = relay_file_read_start_pos(*ppos, buf); - avail = relay_file_read_subbuf_avail(read_start, buf); - if (!avail) - goto out; - - from = buf->start + read_start; - ret = count = min(count, avail); - if (copy_to_user(buffer, from, count)) { - ret = -EFAULT; - goto out; - } - relay_file_read_consume(buf, read_start, count); - *ppos = relay_file_read_end_pos(buf, read_start, count); -out: - mutex_unlock(&inode->i_mutex); - return ret; -} - -struct file_operations relay_file_operations = { - .open = relay_file_open, - .poll = relay_file_poll, - .mmap = relay_file_mmap, - .read = relay_file_read, - .llseek = no_llseek, - .release = relay_file_release, -}; - -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; - int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; - - 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, mode, NULL, NULL); - - 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) - -EXPORT_SYMBOL_GPL(relay_file_operations); -EXPORT_SYMBOL_GPL(relayfs_create_dir); -EXPORT_SYMBOL_GPL(relayfs_remove_dir); -EXPORT_SYMBOL_GPL(relayfs_create_file); -EXPORT_SYMBOL_GPL(relayfs_remove_file); - -MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>"); -MODULE_DESCRIPTION("Relay Filesystem"); -MODULE_LICENSE("GPL"); - |