2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include <linux/ctype.h>
7 #include <linux/dcache.h>
8 #include <linux/file.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/mount.h>
15 #include <linux/slab.h>
16 #include <linux/statfs.h>
17 #include <linux/types.h>
18 #include <linux/pid_namespace.h>
19 #include <linux/namei.h>
20 #include <asm/uaccess.h>
23 static struct inode *get_inode(struct super_block *, struct dentry *);
26 struct list_head list;
27 char contents[PAGE_SIZE - sizeof(struct list_head)];
30 struct hppfs_private {
31 struct file *proc_file;
34 struct hppfs_data *contents;
37 struct hppfs_inode_info {
38 struct dentry *proc_dentry;
39 struct inode vfs_inode;
42 static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
44 return container_of(inode, struct hppfs_inode_info, vfs_inode);
47 #define HPPFS_SUPER_MAGIC 0xb00000ee
49 static const struct super_operations hppfs_sbops;
51 static int is_pid(struct dentry *dentry)
53 struct super_block *sb;
57 if (dentry->d_parent != sb->s_root)
60 for (i = 0; i < dentry->d_name.len; i++) {
61 if (!isdigit(dentry->d_name.name[i]))
67 static char *dentry_name(struct dentry *dentry, int extra)
69 struct dentry *parent;
72 int len, seg_len, root_len;
76 while (parent->d_parent != parent) {
78 len += strlen("pid") + 1;
79 else len += parent->d_name.len + 1;
80 parent = parent->d_parent;
84 root_len = strlen(root);
86 name = kmalloc(len + extra + 1, GFP_KERNEL);
92 while (parent->d_parent != parent) {
95 seg_len = strlen(seg_name);
98 seg_name = parent->d_name.name;
99 seg_len = parent->d_name.len;
104 memcpy(&name[len + 1], seg_name, seg_len);
105 parent = parent->d_parent;
107 memcpy(name, root, root_len);
111 static int file_removed(struct dentry *dentry, const char *file)
118 extra += strlen(file) + 1;
120 host_file = dentry_name(dentry, extra + strlen("/remove"));
121 if (host_file == NULL) {
122 printk(KERN_ERR "file_removed : allocation failed\n");
127 strcat(host_file, "/");
128 strcat(host_file, file);
130 strcat(host_file, "/remove");
132 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
141 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
144 struct dentry *proc_dentry, *parent;
145 struct qstr *name = &dentry->d_name;
149 deleted = file_removed(dentry, NULL);
151 return ERR_PTR(deleted);
153 return ERR_PTR(-ENOENT);
155 parent = HPPFS_I(ino)->proc_dentry;
156 mutex_lock(&parent->d_inode->i_mutex);
157 proc_dentry = lookup_one_len(name->name, parent, name->len);
158 mutex_unlock(&parent->d_inode->i_mutex);
160 if (IS_ERR(proc_dentry))
164 inode = get_inode(ino->i_sb, proc_dentry);
168 d_add(dentry, inode);
175 static const struct inode_operations hppfs_file_iops = {
178 static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
179 loff_t *ppos, int is_user)
181 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
184 read = file_inode(file)->i_fop->read;
189 n = (*read)(file, buf, count, &file->f_pos);
199 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
206 new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
207 if (new_buf == NULL) {
208 printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
213 cur = min_t(ssize_t, count, PAGE_SIZE);
214 err = os_read_file(fd, new_buf, cur);
216 printk(KERN_ERR "hppfs_read : read failed, "
217 "errno = %d\n", err);
223 if (copy_to_user(buf, new_buf, err)) {
236 static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
239 struct hppfs_private *hppfs = file->private_data;
240 struct hppfs_data *data;
244 if (hppfs->contents != NULL) {
247 if (*ppos >= hppfs->len)
250 data = hppfs->contents;
252 while (off >= sizeof(data->contents)) {
253 data = list_entry(data->list.next, struct hppfs_data,
255 off -= sizeof(data->contents);
258 if (off + count > hppfs->len)
259 count = hppfs->len - off;
260 rem = copy_to_user(buf, &data->contents[off], count);
261 *ppos += count - rem;
264 } else if (hppfs->host_fd != -1) {
265 err = os_seek_file(hppfs->host_fd, *ppos);
267 printk(KERN_ERR "hppfs_read : seek failed, "
268 "errno = %d\n", err);
271 err = hppfs_read_file(hppfs->host_fd, buf, count);
273 printk(KERN_ERR "hppfs_read: read failed: %d\n", err);
280 else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
285 static ssize_t hppfs_write(struct file *file, const char __user *buf,
286 size_t len, loff_t *ppos)
288 struct hppfs_private *data = file->private_data;
289 struct file *proc_file = data->proc_file;
290 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
292 write = file_inode(proc_file)->i_fop->write;
293 return (*write)(proc_file, buf, len, ppos);
296 static int open_host_sock(char *host_file, int *filter_out)
301 end = &host_file[strlen(host_file)];
304 fd = os_connect_socket(host_file);
310 fd = os_connect_socket(host_file);
314 static void free_contents(struct hppfs_data *head)
316 struct hppfs_data *data;
317 struct list_head *ele, *next;
322 list_for_each_safe(ele, next, &head->list) {
323 data = list_entry(ele, struct hppfs_data, list);
329 static struct hppfs_data *hppfs_get_data(int fd, int filter,
330 struct file *proc_file,
331 struct file *hppfs_file,
334 struct hppfs_data *data, *new, *head;
338 data = kmalloc(sizeof(*data), GFP_KERNEL);
340 printk(KERN_ERR "hppfs_get_data : head allocation failed\n");
344 INIT_LIST_HEAD(&data->list);
350 while ((n = read_proc(proc_file, data->contents,
351 sizeof(data->contents), NULL, 0)) > 0)
352 os_write_file(fd, data->contents, n);
353 err = os_shutdown_socket(fd, 0, 1);
355 printk(KERN_ERR "hppfs_get_data : failed to shut down "
361 n = os_read_file(fd, data->contents, sizeof(data->contents));
364 printk(KERN_ERR "hppfs_get_data : read failed, "
365 "errno = %d\n", err);
372 if (n < sizeof(data->contents))
375 new = kmalloc(sizeof(*data), GFP_KERNEL);
377 printk(KERN_ERR "hppfs_get_data : data allocation "
383 INIT_LIST_HEAD(&new->list);
384 list_add(&new->list, &data->list);
395 static struct hppfs_private *hppfs_data(void)
397 struct hppfs_private *data;
399 data = kmalloc(sizeof(*data), GFP_KERNEL);
403 *data = ((struct hppfs_private ) { .host_fd = -1,
405 .contents = NULL } );
409 static int file_mode(int fmode)
411 if (fmode == (FMODE_READ | FMODE_WRITE))
413 if (fmode == FMODE_READ)
415 if (fmode == FMODE_WRITE)
420 static int hppfs_open(struct inode *inode, struct file *file)
422 const struct cred *cred = file->f_cred;
423 struct hppfs_private *data;
426 int err, fd, type, filter;
433 host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
434 if (host_file == NULL)
437 path.mnt = inode->i_sb->s_fs_info;
438 path.dentry = HPPFS_I(inode)->proc_dentry;
440 data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
441 err = PTR_ERR(data->proc_file);
442 if (IS_ERR(data->proc_file))
445 type = os_file_type(host_file);
446 if (type == OS_TYPE_FILE) {
447 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
451 printk(KERN_ERR "hppfs_open : failed to open '%s', "
452 "errno = %d\n", host_file, -fd);
454 data->contents = NULL;
455 } else if (type == OS_TYPE_DIR) {
456 fd = open_host_sock(host_file, &filter);
458 data->contents = hppfs_get_data(fd, filter,
461 if (!IS_ERR(data->contents))
464 printk(KERN_ERR "hppfs_open : failed to open a socket "
465 "in '%s', errno = %d\n", host_file, -fd);
469 file->private_data = data;
475 free_contents(data->contents);
481 static int hppfs_dir_open(struct inode *inode, struct file *file)
483 const struct cred *cred = file->f_cred;
484 struct hppfs_private *data;
493 path.mnt = inode->i_sb->s_fs_info;
494 path.dentry = HPPFS_I(inode)->proc_dentry;
495 data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
496 err = PTR_ERR(data->proc_file);
497 if (IS_ERR(data->proc_file))
500 file->private_data = data;
509 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
511 struct hppfs_private *data = file->private_data;
512 struct file *proc_file = data->proc_file;
513 loff_t (*llseek)(struct file *, loff_t, int);
516 llseek = file_inode(proc_file)->i_fop->llseek;
517 if (llseek != NULL) {
518 ret = (*llseek)(proc_file, off, where);
523 return default_llseek(file, off, where);
526 static int hppfs_release(struct inode *inode, struct file *file)
528 struct hppfs_private *data = file->private_data;
529 struct file *proc_file = data->proc_file;
536 static const struct file_operations hppfs_file_fops = {
538 .llseek = hppfs_llseek,
540 .write = hppfs_write,
542 .release = hppfs_release,
545 struct hppfs_dirent {
546 struct dir_context ctx;
547 struct dir_context *caller;
548 struct dentry *dentry;
551 static int hppfs_filldir(struct dir_context *ctx, const char *name, int size,
552 loff_t offset, u64 inode, unsigned int type)
554 struct hppfs_dirent *dirent =
555 container_of(ctx, struct hppfs_dirent, ctx);
557 if (file_removed(dirent->dentry, name))
560 dirent->caller->pos = dirent->ctx.pos;
561 return !dir_emit(dirent->caller, name, size, inode, type);
564 static int hppfs_readdir(struct file *file, struct dir_context *ctx)
566 struct hppfs_private *data = file->private_data;
567 struct file *proc_file = data->proc_file;
568 struct hppfs_dirent d = {
569 .ctx.actor = hppfs_filldir,
571 .dentry = file->f_path.dentry
574 proc_file->f_pos = ctx->pos;
575 err = iterate_dir(proc_file, &d.ctx);
576 ctx->pos = d.ctx.pos;
580 static const struct file_operations hppfs_dir_fops = {
582 .iterate = hppfs_readdir,
583 .open = hppfs_dir_open,
584 .llseek = default_llseek,
585 .release = hppfs_release,
588 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
595 sf->f_type = HPPFS_SUPER_MAGIC;
599 static struct inode *hppfs_alloc_inode(struct super_block *sb)
601 struct hppfs_inode_info *hi;
603 hi = kmalloc(sizeof(*hi), GFP_KERNEL);
607 hi->proc_dentry = NULL;
608 inode_init_once(&hi->vfs_inode);
609 return &hi->vfs_inode;
612 void hppfs_evict_inode(struct inode *ino)
615 dput(HPPFS_I(ino)->proc_dentry);
616 mntput(ino->i_sb->s_fs_info);
619 static void hppfs_i_callback(struct rcu_head *head)
621 struct inode *inode = container_of(head, struct inode, i_rcu);
622 kfree(HPPFS_I(inode));
625 static void hppfs_destroy_inode(struct inode *inode)
627 call_rcu(&inode->i_rcu, hppfs_i_callback);
630 static const struct super_operations hppfs_sbops = {
631 .alloc_inode = hppfs_alloc_inode,
632 .destroy_inode = hppfs_destroy_inode,
633 .evict_inode = hppfs_evict_inode,
634 .statfs = hppfs_statfs,
637 static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
640 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
641 return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer,
645 static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
647 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
649 return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
652 static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
655 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
657 if (proc_dentry->d_inode->i_op->put_link)
658 proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie);
661 static const struct inode_operations hppfs_dir_iops = {
662 .lookup = hppfs_lookup,
665 static const struct inode_operations hppfs_link_iops = {
666 .readlink = hppfs_readlink,
667 .follow_link = hppfs_follow_link,
668 .put_link = hppfs_put_link,
671 static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
673 struct inode *proc_ino = dentry->d_inode;
674 struct inode *inode = new_inode(sb);
681 if (d_is_dir(dentry)) {
682 inode->i_op = &hppfs_dir_iops;
683 inode->i_fop = &hppfs_dir_fops;
684 } else if (d_is_symlink(dentry)) {
685 inode->i_op = &hppfs_link_iops;
686 inode->i_fop = &hppfs_file_fops;
688 inode->i_op = &hppfs_file_iops;
689 inode->i_fop = &hppfs_file_fops;
692 HPPFS_I(inode)->proc_dentry = dentry;
694 inode->i_uid = proc_ino->i_uid;
695 inode->i_gid = proc_ino->i_gid;
696 inode->i_atime = proc_ino->i_atime;
697 inode->i_mtime = proc_ino->i_mtime;
698 inode->i_ctime = proc_ino->i_ctime;
699 inode->i_ino = proc_ino->i_ino;
700 inode->i_mode = proc_ino->i_mode;
701 set_nlink(inode, proc_ino->i_nlink);
702 inode->i_size = proc_ino->i_size;
703 inode->i_blocks = proc_ino->i_blocks;
708 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
710 struct inode *root_inode;
711 struct vfsmount *proc_mnt;
714 proc_mnt = mntget(task_active_pid_ns(current)->proc_mnt);
715 if (IS_ERR(proc_mnt))
718 sb->s_blocksize = 1024;
719 sb->s_blocksize_bits = 10;
720 sb->s_magic = HPPFS_SUPER_MAGIC;
721 sb->s_op = &hppfs_sbops;
722 sb->s_fs_info = proc_mnt;
725 root_inode = get_inode(sb, dget(proc_mnt->mnt_root));
726 sb->s_root = d_make_root(root_inode);
738 static struct dentry *hppfs_read_super(struct file_system_type *type,
739 int flags, const char *dev_name,
742 return mount_nodev(type, flags, data, hppfs_fill_super);
745 static struct file_system_type hppfs_type = {
746 .owner = THIS_MODULE,
748 .mount = hppfs_read_super,
749 .kill_sb = kill_anon_super,
752 MODULE_ALIAS_FS("hppfs");
754 static int __init init_hppfs(void)
756 return register_filesystem(&hppfs_type);
759 static void __exit exit_hppfs(void)
761 unregister_filesystem(&hppfs_type);
764 module_init(init_hppfs)
765 module_exit(exit_hppfs)
766 MODULE_LICENSE("GPL");