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;
76 while (parent->d_parent != parent) {
78 len += strlen("pid") + 1;
79 else len += parent->d_name.len + 1;
80 parent = parent->d_parent;
85 name = kmalloc(len + extra + 1, GFP_KERNEL);
91 while (parent->d_parent != parent) {
94 seg_len = strlen("pid");
97 seg_name = parent->d_name.name;
98 seg_len = parent->d_name.len;
103 strncpy(&name[len + 1], seg_name, seg_len);
104 parent = parent->d_parent;
106 strncpy(name, root, strlen(root));
110 static int file_removed(struct dentry *dentry, const char *file)
117 extra += strlen(file) + 1;
119 host_file = dentry_name(dentry, extra + strlen("/remove"));
120 if (host_file == NULL) {
121 printk(KERN_ERR "file_removed : allocation failed\n");
126 strcat(host_file, "/");
127 strcat(host_file, file);
129 strcat(host_file, "/remove");
131 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
140 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
143 struct dentry *proc_dentry, *parent;
144 struct qstr *name = &dentry->d_name;
148 deleted = file_removed(dentry, NULL);
150 return ERR_PTR(deleted);
152 return ERR_PTR(-ENOENT);
154 parent = HPPFS_I(ino)->proc_dentry;
155 mutex_lock(&parent->d_inode->i_mutex);
156 proc_dentry = lookup_one_len(name->name, parent, name->len);
157 mutex_unlock(&parent->d_inode->i_mutex);
159 if (IS_ERR(proc_dentry))
163 inode = get_inode(ino->i_sb, proc_dentry);
167 d_add(dentry, inode);
174 static const struct inode_operations hppfs_file_iops = {
177 static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
178 loff_t *ppos, int is_user)
180 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
183 read = file_inode(file)->i_fop->read;
188 n = (*read)(file, buf, count, &file->f_pos);
198 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
205 new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
206 if (new_buf == NULL) {
207 printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
212 cur = min_t(ssize_t, count, PAGE_SIZE);
213 err = os_read_file(fd, new_buf, cur);
215 printk(KERN_ERR "hppfs_read : read failed, "
216 "errno = %d\n", err);
222 if (copy_to_user(buf, new_buf, err)) {
235 static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
238 struct hppfs_private *hppfs = file->private_data;
239 struct hppfs_data *data;
243 if (hppfs->contents != NULL) {
246 if (*ppos >= hppfs->len)
249 data = hppfs->contents;
251 while (off >= sizeof(data->contents)) {
252 data = list_entry(data->list.next, struct hppfs_data,
254 off -= sizeof(data->contents);
257 if (off + count > hppfs->len)
258 count = hppfs->len - off;
259 rem = copy_to_user(buf, &data->contents[off], count);
260 *ppos += count - rem;
263 } else if (hppfs->host_fd != -1) {
264 err = os_seek_file(hppfs->host_fd, *ppos);
266 printk(KERN_ERR "hppfs_read : seek failed, "
267 "errno = %d\n", err);
270 err = hppfs_read_file(hppfs->host_fd, buf, count);
272 printk(KERN_ERR "hppfs_read: read failed: %d\n", err);
279 else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
284 static ssize_t hppfs_write(struct file *file, const char __user *buf,
285 size_t len, loff_t *ppos)
287 struct hppfs_private *data = file->private_data;
288 struct file *proc_file = data->proc_file;
289 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
291 write = file_inode(proc_file)->i_fop->write;
292 return (*write)(proc_file, buf, len, ppos);
295 static int open_host_sock(char *host_file, int *filter_out)
300 end = &host_file[strlen(host_file)];
303 fd = os_connect_socket(host_file);
309 fd = os_connect_socket(host_file);
313 static void free_contents(struct hppfs_data *head)
315 struct hppfs_data *data;
316 struct list_head *ele, *next;
321 list_for_each_safe(ele, next, &head->list) {
322 data = list_entry(ele, struct hppfs_data, list);
328 static struct hppfs_data *hppfs_get_data(int fd, int filter,
329 struct file *proc_file,
330 struct file *hppfs_file,
333 struct hppfs_data *data, *new, *head;
337 data = kmalloc(sizeof(*data), GFP_KERNEL);
339 printk(KERN_ERR "hppfs_get_data : head allocation failed\n");
343 INIT_LIST_HEAD(&data->list);
349 while ((n = read_proc(proc_file, data->contents,
350 sizeof(data->contents), NULL, 0)) > 0)
351 os_write_file(fd, data->contents, n);
352 err = os_shutdown_socket(fd, 0, 1);
354 printk(KERN_ERR "hppfs_get_data : failed to shut down "
360 n = os_read_file(fd, data->contents, sizeof(data->contents));
363 printk(KERN_ERR "hppfs_get_data : read failed, "
364 "errno = %d\n", err);
371 if (n < sizeof(data->contents))
374 new = kmalloc(sizeof(*data), GFP_KERNEL);
376 printk(KERN_ERR "hppfs_get_data : data allocation "
382 INIT_LIST_HEAD(&new->list);
383 list_add(&new->list, &data->list);
394 static struct hppfs_private *hppfs_data(void)
396 struct hppfs_private *data;
398 data = kmalloc(sizeof(*data), GFP_KERNEL);
402 *data = ((struct hppfs_private ) { .host_fd = -1,
404 .contents = NULL } );
408 static int file_mode(int fmode)
410 if (fmode == (FMODE_READ | FMODE_WRITE))
412 if (fmode == FMODE_READ)
414 if (fmode == FMODE_WRITE)
419 static int hppfs_open(struct inode *inode, struct file *file)
421 const struct cred *cred = file->f_cred;
422 struct hppfs_private *data;
425 int err, fd, type, filter;
432 host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
433 if (host_file == NULL)
436 path.mnt = inode->i_sb->s_fs_info;
437 path.dentry = HPPFS_I(inode)->proc_dentry;
439 data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
440 err = PTR_ERR(data->proc_file);
441 if (IS_ERR(data->proc_file))
444 type = os_file_type(host_file);
445 if (type == OS_TYPE_FILE) {
446 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
450 printk(KERN_ERR "hppfs_open : failed to open '%s', "
451 "errno = %d\n", host_file, -fd);
453 data->contents = NULL;
454 } else if (type == OS_TYPE_DIR) {
455 fd = open_host_sock(host_file, &filter);
457 data->contents = hppfs_get_data(fd, filter,
460 if (!IS_ERR(data->contents))
463 printk(KERN_ERR "hppfs_open : failed to open a socket "
464 "in '%s', errno = %d\n", host_file, -fd);
468 file->private_data = data;
474 free_contents(data->contents);
480 static int hppfs_dir_open(struct inode *inode, struct file *file)
482 const struct cred *cred = file->f_cred;
483 struct hppfs_private *data;
492 path.mnt = inode->i_sb->s_fs_info;
493 path.dentry = HPPFS_I(inode)->proc_dentry;
494 data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
495 err = PTR_ERR(data->proc_file);
496 if (IS_ERR(data->proc_file))
499 file->private_data = data;
508 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
510 struct hppfs_private *data = file->private_data;
511 struct file *proc_file = data->proc_file;
512 loff_t (*llseek)(struct file *, loff_t, int);
515 llseek = file_inode(proc_file)->i_fop->llseek;
516 if (llseek != NULL) {
517 ret = (*llseek)(proc_file, off, where);
522 return default_llseek(file, off, where);
525 static int hppfs_release(struct inode *inode, struct file *file)
527 struct hppfs_private *data = file->private_data;
528 struct file *proc_file = data->proc_file;
535 static const struct file_operations hppfs_file_fops = {
537 .llseek = hppfs_llseek,
539 .write = hppfs_write,
541 .release = hppfs_release,
544 struct hppfs_dirent {
545 struct dir_context ctx;
546 struct dir_context *caller;
547 struct dentry *dentry;
550 static int hppfs_filldir(void *d, const char *name, int size,
551 loff_t offset, u64 inode, unsigned int type)
553 struct hppfs_dirent *dirent = d;
555 if (file_removed(dirent->dentry, name))
558 dirent->caller->pos = dirent->ctx.pos;
559 return !dir_emit(dirent->caller, name, size, inode, type);
562 static int hppfs_readdir(struct file *file, struct dir_context *ctx)
564 struct hppfs_private *data = file->private_data;
565 struct file *proc_file = data->proc_file;
566 struct hppfs_dirent d = {
567 .ctx.actor = hppfs_filldir,
569 .dentry = file->f_path.dentry
572 proc_file->f_pos = ctx->pos;
573 err = iterate_dir(proc_file, &d.ctx);
574 ctx->pos = d.ctx.pos;
578 static const struct file_operations hppfs_dir_fops = {
580 .iterate = hppfs_readdir,
581 .open = hppfs_dir_open,
582 .llseek = default_llseek,
583 .release = hppfs_release,
586 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
593 sf->f_type = HPPFS_SUPER_MAGIC;
597 static struct inode *hppfs_alloc_inode(struct super_block *sb)
599 struct hppfs_inode_info *hi;
601 hi = kmalloc(sizeof(*hi), GFP_KERNEL);
605 hi->proc_dentry = NULL;
606 inode_init_once(&hi->vfs_inode);
607 return &hi->vfs_inode;
610 void hppfs_evict_inode(struct inode *ino)
613 dput(HPPFS_I(ino)->proc_dentry);
614 mntput(ino->i_sb->s_fs_info);
617 static void hppfs_i_callback(struct rcu_head *head)
619 struct inode *inode = container_of(head, struct inode, i_rcu);
620 kfree(HPPFS_I(inode));
623 static void hppfs_destroy_inode(struct inode *inode)
625 call_rcu(&inode->i_rcu, hppfs_i_callback);
628 static const struct super_operations hppfs_sbops = {
629 .alloc_inode = hppfs_alloc_inode,
630 .destroy_inode = hppfs_destroy_inode,
631 .evict_inode = hppfs_evict_inode,
632 .statfs = hppfs_statfs,
635 static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
638 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
639 return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer,
643 static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
645 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
647 return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
650 static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
653 struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
655 if (proc_dentry->d_inode->i_op->put_link)
656 proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie);
659 static const struct inode_operations hppfs_dir_iops = {
660 .lookup = hppfs_lookup,
663 static const struct inode_operations hppfs_link_iops = {
664 .readlink = hppfs_readlink,
665 .follow_link = hppfs_follow_link,
666 .put_link = hppfs_put_link,
669 static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
671 struct inode *proc_ino = dentry->d_inode;
672 struct inode *inode = new_inode(sb);
679 if (S_ISDIR(dentry->d_inode->i_mode)) {
680 inode->i_op = &hppfs_dir_iops;
681 inode->i_fop = &hppfs_dir_fops;
682 } else if (S_ISLNK(dentry->d_inode->i_mode)) {
683 inode->i_op = &hppfs_link_iops;
684 inode->i_fop = &hppfs_file_fops;
686 inode->i_op = &hppfs_file_iops;
687 inode->i_fop = &hppfs_file_fops;
690 HPPFS_I(inode)->proc_dentry = dentry;
692 inode->i_uid = proc_ino->i_uid;
693 inode->i_gid = proc_ino->i_gid;
694 inode->i_atime = proc_ino->i_atime;
695 inode->i_mtime = proc_ino->i_mtime;
696 inode->i_ctime = proc_ino->i_ctime;
697 inode->i_ino = proc_ino->i_ino;
698 inode->i_mode = proc_ino->i_mode;
699 set_nlink(inode, proc_ino->i_nlink);
700 inode->i_size = proc_ino->i_size;
701 inode->i_blocks = proc_ino->i_blocks;
706 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
708 struct inode *root_inode;
709 struct vfsmount *proc_mnt;
712 proc_mnt = mntget(task_active_pid_ns(current)->proc_mnt);
713 if (IS_ERR(proc_mnt))
716 sb->s_blocksize = 1024;
717 sb->s_blocksize_bits = 10;
718 sb->s_magic = HPPFS_SUPER_MAGIC;
719 sb->s_op = &hppfs_sbops;
720 sb->s_fs_info = proc_mnt;
723 root_inode = get_inode(sb, dget(proc_mnt->mnt_root));
724 sb->s_root = d_make_root(root_inode);
736 static struct dentry *hppfs_read_super(struct file_system_type *type,
737 int flags, const char *dev_name,
740 return mount_nodev(type, flags, data, hppfs_fill_super);
743 static struct file_system_type hppfs_type = {
744 .owner = THIS_MODULE,
746 .mount = hppfs_read_super,
747 .kill_sb = kill_anon_super,
750 MODULE_ALIAS_FS("hppfs");
752 static int __init init_hppfs(void)
754 return register_filesystem(&hppfs_type);
757 static void __exit exit_hppfs(void)
759 unregister_filesystem(&hppfs_type);
762 module_init(init_hppfs)
763 module_exit(exit_hppfs)
764 MODULE_LICENSE("GPL");