| /* -*- c -*- --------------------------------------------------------------- * | 
 |  * | 
 |  * linux/fs/autofs/inode.c | 
 |  * | 
 |  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | 
 |  * | 
 |  * This file is part of the Linux kernel and is made available under | 
 |  * the terms of the GNU General Public License, version 2, or at your | 
 |  * option, any later version, incorporated herein by reference. | 
 |  * | 
 |  * ------------------------------------------------------------------------- */ | 
 |  | 
 | #include <linux/kernel.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/file.h> | 
 | #include <linux/pagemap.h> | 
 | #include <linux/parser.h> | 
 | #include <linux/bitops.h> | 
 | #include <linux/smp_lock.h> | 
 | #include "autofs_i.h" | 
 | #include <linux/module.h> | 
 |  | 
 | static void ino_lnkfree(struct autofs_info *ino) | 
 | { | 
 | 	kfree(ino->u.symlink); | 
 | 	ino->u.symlink = NULL; | 
 | } | 
 |  | 
 | struct autofs_info *autofs4_init_ino(struct autofs_info *ino, | 
 | 				     struct autofs_sb_info *sbi, mode_t mode) | 
 | { | 
 | 	int reinit = 1; | 
 |  | 
 | 	if (ino == NULL) { | 
 | 		reinit = 0; | 
 | 		ino = kmalloc(sizeof(*ino), GFP_KERNEL); | 
 | 	} | 
 |  | 
 | 	if (ino == NULL) | 
 | 		return NULL; | 
 |  | 
 | 	ino->flags = 0; | 
 | 	ino->mode = mode; | 
 | 	ino->inode = NULL; | 
 | 	ino->dentry = NULL; | 
 | 	ino->size = 0; | 
 |  | 
 | 	ino->last_used = jiffies; | 
 |  | 
 | 	ino->sbi = sbi; | 
 |  | 
 | 	if (reinit && ino->free) | 
 | 		(ino->free)(ino); | 
 |  | 
 | 	memset(&ino->u, 0, sizeof(ino->u)); | 
 |  | 
 | 	ino->free = NULL; | 
 |  | 
 | 	if (S_ISLNK(mode)) | 
 | 		ino->free = ino_lnkfree; | 
 |  | 
 | 	return ino; | 
 | } | 
 |  | 
 | void autofs4_free_ino(struct autofs_info *ino) | 
 | { | 
 | 	if (ino->dentry) { | 
 | 		ino->dentry->d_fsdata = NULL; | 
 | 		if (ino->dentry->d_inode) | 
 | 			dput(ino->dentry); | 
 | 		ino->dentry = NULL; | 
 | 	} | 
 | 	if (ino->free) | 
 | 		(ino->free)(ino); | 
 | 	kfree(ino); | 
 | } | 
 |  | 
 | /* | 
 |  * Deal with the infamous "Busy inodes after umount ..." message. | 
 |  * | 
 |  * Clean up the dentry tree. This happens with autofs if the user | 
 |  * space program goes away due to a SIGKILL, SIGSEGV etc. | 
 |  */ | 
 | static void autofs4_force_release(struct autofs_sb_info *sbi) | 
 | { | 
 | 	struct dentry *this_parent = sbi->root; | 
 | 	struct list_head *next; | 
 |  | 
 | 	spin_lock(&dcache_lock); | 
 | repeat: | 
 | 	next = this_parent->d_subdirs.next; | 
 | resume: | 
 | 	while (next != &this_parent->d_subdirs) { | 
 | 		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); | 
 |  | 
 | 		/* Negative dentry - don`t care */ | 
 | 		if (!simple_positive(dentry)) { | 
 | 			next = next->next; | 
 | 			continue; | 
 | 		} | 
 |  | 
 | 		if (!list_empty(&dentry->d_subdirs)) { | 
 | 			this_parent = dentry; | 
 | 			goto repeat; | 
 | 		} | 
 |  | 
 | 		next = next->next; | 
 | 		spin_unlock(&dcache_lock); | 
 |  | 
 | 		DPRINTK("dentry %p %.*s", | 
 | 			dentry, (int)dentry->d_name.len, dentry->d_name.name); | 
 |  | 
 | 		dput(dentry); | 
 | 		spin_lock(&dcache_lock); | 
 | 	} | 
 |  | 
 | 	if (this_parent != sbi->root) { | 
 | 		struct dentry *dentry = this_parent; | 
 |  | 
 | 		next = this_parent->d_u.d_child.next; | 
 | 		this_parent = this_parent->d_parent; | 
 | 		spin_unlock(&dcache_lock); | 
 | 		DPRINTK("parent dentry %p %.*s", | 
 | 			dentry, (int)dentry->d_name.len, dentry->d_name.name); | 
 | 		dput(dentry); | 
 | 		spin_lock(&dcache_lock); | 
 | 		goto resume; | 
 | 	} | 
 | 	spin_unlock(&dcache_lock); | 
 |  | 
 | 	dput(sbi->root); | 
 | 	sbi->root = NULL; | 
 | 	shrink_dcache_sb(sbi->sb); | 
 |  | 
 | 	return; | 
 | } | 
 |  | 
 | static void autofs4_put_super(struct super_block *sb) | 
 | { | 
 | 	struct autofs_sb_info *sbi = autofs4_sbi(sb); | 
 |  | 
 | 	sb->s_fs_info = NULL; | 
 |  | 
 | 	if ( !sbi->catatonic ) | 
 | 		autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */ | 
 |  | 
 | 	/* Clean up and release dangling references */ | 
 | 	if (sbi) | 
 | 		autofs4_force_release(sbi); | 
 |  | 
 | 	kfree(sbi); | 
 |  | 
 | 	DPRINTK("shutting down"); | 
 | } | 
 |  | 
 | static struct super_operations autofs4_sops = { | 
 | 	.put_super	= autofs4_put_super, | 
 | 	.statfs		= simple_statfs, | 
 | }; | 
 |  | 
 | enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto}; | 
 |  | 
 | static match_table_t tokens = { | 
 | 	{Opt_fd, "fd=%u"}, | 
 | 	{Opt_uid, "uid=%u"}, | 
 | 	{Opt_gid, "gid=%u"}, | 
 | 	{Opt_pgrp, "pgrp=%u"}, | 
 | 	{Opt_minproto, "minproto=%u"}, | 
 | 	{Opt_maxproto, "maxproto=%u"}, | 
 | 	{Opt_err, NULL} | 
 | }; | 
 |  | 
 | static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, | 
 | 			 pid_t *pgrp, int *minproto, int *maxproto) | 
 | { | 
 | 	char *p; | 
 | 	substring_t args[MAX_OPT_ARGS]; | 
 | 	int option; | 
 |  | 
 | 	*uid = current->uid; | 
 | 	*gid = current->gid; | 
 | 	*pgrp = process_group(current); | 
 |  | 
 | 	*minproto = AUTOFS_MIN_PROTO_VERSION; | 
 | 	*maxproto = AUTOFS_MAX_PROTO_VERSION; | 
 |  | 
 | 	*pipefd = -1; | 
 |  | 
 | 	if (!options) | 
 | 		return 1; | 
 |  | 
 | 	while ((p = strsep(&options, ",")) != NULL) { | 
 | 		int token; | 
 | 		if (!*p) | 
 | 			continue; | 
 |  | 
 | 		token = match_token(p, tokens, args); | 
 | 		switch (token) { | 
 | 		case Opt_fd: | 
 | 			if (match_int(args, pipefd)) | 
 | 				return 1; | 
 | 			break; | 
 | 		case Opt_uid: | 
 | 			if (match_int(args, &option)) | 
 | 				return 1; | 
 | 			*uid = option; | 
 | 			break; | 
 | 		case Opt_gid: | 
 | 			if (match_int(args, &option)) | 
 | 				return 1; | 
 | 			*gid = option; | 
 | 			break; | 
 | 		case Opt_pgrp: | 
 | 			if (match_int(args, &option)) | 
 | 				return 1; | 
 | 			*pgrp = option; | 
 | 			break; | 
 | 		case Opt_minproto: | 
 | 			if (match_int(args, &option)) | 
 | 				return 1; | 
 | 			*minproto = option; | 
 | 			break; | 
 | 		case Opt_maxproto: | 
 | 			if (match_int(args, &option)) | 
 | 				return 1; | 
 | 			*maxproto = option; | 
 | 			break; | 
 | 		default: | 
 | 			return 1; | 
 | 		} | 
 | 	} | 
 | 	return (*pipefd < 0); | 
 | } | 
 |  | 
 | static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) | 
 | { | 
 | 	struct autofs_info *ino; | 
 |  | 
 | 	ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755); | 
 | 	if (!ino) | 
 | 		return NULL; | 
 |  | 
 | 	return ino; | 
 | } | 
 |  | 
 | int autofs4_fill_super(struct super_block *s, void *data, int silent) | 
 | { | 
 | 	struct inode * root_inode; | 
 | 	struct dentry * root; | 
 | 	struct file * pipe; | 
 | 	int pipefd; | 
 | 	struct autofs_sb_info *sbi; | 
 | 	struct autofs_info *ino; | 
 | 	int minproto, maxproto; | 
 |  | 
 | 	sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL); | 
 | 	if ( !sbi ) | 
 | 		goto fail_unlock; | 
 | 	DPRINTK("starting up, sbi = %p",sbi); | 
 |  | 
 | 	memset(sbi, 0, sizeof(*sbi)); | 
 |  | 
 | 	s->s_fs_info = sbi; | 
 | 	sbi->magic = AUTOFS_SBI_MAGIC; | 
 | 	sbi->root = NULL; | 
 | 	sbi->catatonic = 0; | 
 | 	sbi->exp_timeout = 0; | 
 | 	sbi->oz_pgrp = process_group(current); | 
 | 	sbi->sb = s; | 
 | 	sbi->version = 0; | 
 | 	sbi->sub_version = 0; | 
 | 	init_MUTEX(&sbi->wq_sem); | 
 | 	spin_lock_init(&sbi->fs_lock); | 
 | 	sbi->queues = NULL; | 
 | 	s->s_blocksize = 1024; | 
 | 	s->s_blocksize_bits = 10; | 
 | 	s->s_magic = AUTOFS_SUPER_MAGIC; | 
 | 	s->s_op = &autofs4_sops; | 
 | 	s->s_time_gran = 1; | 
 |  | 
 | 	/* | 
 | 	 * Get the root inode and dentry, but defer checking for errors. | 
 | 	 */ | 
 | 	ino = autofs4_mkroot(sbi); | 
 | 	if (!ino) | 
 | 		goto fail_free; | 
 | 	root_inode = autofs4_get_inode(s, ino); | 
 | 	kfree(ino); | 
 | 	if (!root_inode) | 
 | 		goto fail_free; | 
 |  | 
 | 	root_inode->i_op = &autofs4_root_inode_operations; | 
 | 	root_inode->i_fop = &autofs4_root_operations; | 
 | 	root = d_alloc_root(root_inode); | 
 | 	pipe = NULL; | 
 |  | 
 | 	if (!root) | 
 | 		goto fail_iput; | 
 |  | 
 | 	/* Can this call block? */ | 
 | 	if (parse_options(data, &pipefd, | 
 | 			  &root_inode->i_uid, &root_inode->i_gid, | 
 | 			  &sbi->oz_pgrp, | 
 | 			  &minproto, &maxproto)) { | 
 | 		printk("autofs: called with bogus options\n"); | 
 | 		goto fail_dput; | 
 | 	} | 
 |  | 
 | 	/* Couldn't this be tested earlier? */ | 
 | 	if (maxproto < AUTOFS_MIN_PROTO_VERSION || | 
 | 	    minproto > AUTOFS_MAX_PROTO_VERSION) { | 
 | 		printk("autofs: kernel does not match daemon version " | 
 | 		       "daemon (%d, %d) kernel (%d, %d)\n", | 
 | 			minproto, maxproto, | 
 | 			AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); | 
 | 		goto fail_dput; | 
 | 	} | 
 |  | 
 | 	sbi->version = maxproto > AUTOFS_MAX_PROTO_VERSION ? AUTOFS_MAX_PROTO_VERSION : maxproto; | 
 | 	sbi->sub_version = AUTOFS_PROTO_SUBVERSION; | 
 |  | 
 | 	DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); | 
 | 	pipe = fget(pipefd); | 
 | 	 | 
 | 	if ( !pipe ) { | 
 | 		printk("autofs: could not open pipe file descriptor\n"); | 
 | 		goto fail_dput; | 
 | 	} | 
 | 	if ( !pipe->f_op || !pipe->f_op->write ) | 
 | 		goto fail_fput; | 
 | 	sbi->pipe = pipe; | 
 |  | 
 | 	/* | 
 | 	 * Take a reference to the root dentry so we get a chance to | 
 | 	 * clean up the dentry tree on umount. | 
 | 	 * See autofs4_force_release. | 
 | 	 */ | 
 | 	sbi->root = dget(root); | 
 |  | 
 | 	/* | 
 | 	 * Success! Install the root dentry now to indicate completion. | 
 | 	 */ | 
 | 	s->s_root = root; | 
 | 	return 0; | 
 | 	 | 
 | 	/* | 
 | 	 * Failure ... clean up. | 
 | 	 */ | 
 | fail_fput: | 
 | 	printk("autofs: pipe file descriptor does not contain proper ops\n"); | 
 | 	fput(pipe); | 
 | 	/* fall through */ | 
 | fail_dput: | 
 | 	dput(root); | 
 | 	goto fail_free; | 
 | fail_iput: | 
 | 	printk("autofs: get root dentry failed\n"); | 
 | 	iput(root_inode); | 
 | fail_free: | 
 | 	kfree(sbi); | 
 | fail_unlock: | 
 | 	return -EINVAL; | 
 | } | 
 |  | 
 | struct inode *autofs4_get_inode(struct super_block *sb, | 
 | 				struct autofs_info *inf) | 
 | { | 
 | 	struct inode *inode = new_inode(sb); | 
 |  | 
 | 	if (inode == NULL) | 
 | 		return NULL; | 
 |  | 
 | 	inf->inode = inode; | 
 | 	inode->i_mode = inf->mode; | 
 | 	if (sb->s_root) { | 
 | 		inode->i_uid = sb->s_root->d_inode->i_uid; | 
 | 		inode->i_gid = sb->s_root->d_inode->i_gid; | 
 | 	} else { | 
 | 		inode->i_uid = 0; | 
 | 		inode->i_gid = 0; | 
 | 	} | 
 | 	inode->i_blksize = PAGE_CACHE_SIZE; | 
 | 	inode->i_blocks = 0; | 
 | 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | 
 |  | 
 | 	if (S_ISDIR(inf->mode)) { | 
 | 		inode->i_nlink = 2; | 
 | 		inode->i_op = &autofs4_dir_inode_operations; | 
 | 		inode->i_fop = &autofs4_dir_operations; | 
 | 	} else if (S_ISLNK(inf->mode)) { | 
 | 		inode->i_size = inf->size; | 
 | 		inode->i_op = &autofs4_symlink_inode_operations; | 
 | 	} | 
 |  | 
 | 	return inode; | 
 | } |