drivers/staging/autofs/inode.c - linux - Git at Google

 /* -*- linux-c -*- --------------------------------------------------------- *
  *
  * drivers/staging/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/mm.h>
 #include <linux/slab.h>
 #include <linux/file.h>
 #include <linux/parser.h>
 #include <linux/bitops.h>
 #include <linux/magic.h>
 #include "autofs_i.h"
 #include <linux/module.h>

 void autofs_kill_sb(struct super_block *sb)
 {
 	struct autofs_sb_info *sbi = autofs_sbi(sb);
 	unsigned int n;

 	/*
 	 * In the event of a failure in get_sb_nodev the superblock
 	 * info is not present so nothing else has been setup, so
 	 * just call kill_anon_super when we are called from
 	 * deactivate_super.
 	 */
 	if (!sbi)
 		goto out_kill_sb;

 	if (!sbi->catatonic)
 		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */

 	put_pid(sbi->oz_pgrp);

 	autofs_hash_nuke(sbi);
 	for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
 		if (test_bit(n, sbi->symlink_bitmap))
 			kfree(sbi->symlink[n].data);
 	}

 	kfree(sb->s_fs_info);

 out_kill_sb:
 	DPRINTK(("autofs: shutting down\n"));
 	kill_anon_super(sb);
 }

 static const struct super_operations autofs_sops = {
 	.statfs		= simple_statfs,
 	.show_options	= generic_show_options,
 };

 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};

 static const match_table_t autofs_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 = task_pgrp_nr(current);

 	*minproto = *maxproto = AUTOFS_PROTO_VERSION;

 	*pipefd = -1;

 	if (!options)
 		return 1;

 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
 		if (!*p)
 			continue;

 		token = match_token(p, autofs_tokens, args);
 		switch (token) {
 		case Opt_fd:
 			if (match_int(&args[0], &option))
 				return 1;
 			*pipefd = option;
 			break;
 		case Opt_uid:
 			if (match_int(&args[0], &option))
 				return 1;
 			*uid = option;
 			break;
 		case Opt_gid:
 			if (match_int(&args[0], &option))
 				return 1;
 			*gid = option;
 			break;
 		case Opt_pgrp:
 			if (match_int(&args[0], &option))
 				return 1;
 			*pgrp = option;
 			break;
 		case Opt_minproto:
 			if (match_int(&args[0], &option))
 				return 1;
 			*minproto = option;
 			break;
 		case Opt_maxproto:
 			if (match_int(&args[0], &option))
 				return 1;
 			*maxproto = option;
 			break;
 		default:
 			return 1;
 		}
 	}
 	return (*pipefd < 0);
 }

 int autofs_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;
 	int minproto, maxproto;
 	pid_t pgid;

 	save_mount_options(s, data);

 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
 		goto fail_unlock;
 	DPRINTK(("autofs: starting up, sbi = %p\n",sbi));

 	s->s_fs_info = sbi;
 	sbi->magic = AUTOFS_SBI_MAGIC;
 	sbi->pipe = NULL;
 	sbi->catatonic = 1;
 	sbi->exp_timeout = 0;
 	autofs_initialize_hash(&sbi->dirhash);
 	sbi->queues = NULL;
 	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
 	sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
 	s->s_blocksize = 1024;
 	s->s_blocksize_bits = 10;
 	s->s_magic = AUTOFS_SUPER_MAGIC;
 	s->s_op = &autofs_sops;
 	s->s_time_gran = 1;
 	sbi->sb = s;

 	root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
 	if (IS_ERR(root_inode))
 		goto fail_free;
 	root = d_alloc_root(root_inode);
 	pipe = NULL;

 	if (!root)
 		goto fail_iput;

 	/* Can this call block?  - WTF cares? s is locked. */
 	if (parse_options(data, &pipefd, &root_inode->i_uid,
 				&root_inode->i_gid, &pgid, &minproto,
 				&maxproto)) {
 		printk("autofs: called with bogus options\n");
 		goto fail_dput;
 	}

 	/* Couldn't this be tested earlier? */
 	if (minproto > AUTOFS_PROTO_VERSION ||
 	     maxproto < AUTOFS_PROTO_VERSION) {
 		printk("autofs: kernel does not match daemon version\n");
 		goto fail_dput;
 	}

 	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid));
 	sbi->oz_pgrp = find_get_pid(pgid);

 	if (!sbi->oz_pgrp) {
 		printk("autofs: could not find process group %d\n", pgid);
 		goto fail_dput;
 	}

 	pipe = fget(pipefd);

 	if (!pipe) {
 		printk("autofs: could not open pipe file descriptor\n");
 		goto fail_put_pid;
 	}

 	if (!pipe->f_op || !pipe->f_op->write)
 		goto fail_fput;
 	sbi->pipe = pipe;
 	sbi->catatonic = 0;

 	/*
 	 * Success! Install the root dentry now to indicate completion.
 	 */
 	s->s_root = root;
 	return 0;

 fail_fput:
 	printk("autofs: pipe file descriptor does not contain proper ops\n");
 	fput(pipe);
 fail_put_pid:
 	put_pid(sbi->oz_pgrp);
 fail_dput:
 	dput(root);
 	goto fail_free;
 fail_iput:
 	printk("autofs: get root dentry failed\n");
 	iput(root_inode);
 fail_free:
 	kfree(sbi);
 	s->s_fs_info = NULL;
 fail_unlock:
 	return -EINVAL;
 }

 struct inode *autofs_iget(struct super_block *sb, unsigned long ino)
 {
 	unsigned int n;
 	struct autofs_sb_info *sbi = autofs_sbi(sb);
 	struct inode *inode;

 	inode = iget_locked(sb, ino);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);
 	if (!(inode->i_state & I_NEW))
 		return inode;

 	/* Initialize to the default case (stub directory) */

 	inode->i_op = &simple_dir_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
 	inode->i_nlink = 2;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;

 	if (ino == AUTOFS_ROOT_INO) {
 		inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
 		inode->i_op = &autofs_root_inode_operations;
 		inode->i_fop = &autofs_root_operations;
 		goto done;
 	}

 	inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
 	inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;

 	if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {
 		/* Symlink inode - should be in symlink list */
 		struct autofs_symlink *sl;

 		n = ino - AUTOFS_FIRST_SYMLINK;
 		if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
 			printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
 			goto done;
 		}

 		inode->i_op = &autofs_symlink_inode_operations;
 		sl = &sbi->symlink[n];
 		inode->i_private = sl;
 		inode->i_mode = S_IFLNK | S_IRWXUGO;
 		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
 		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
 		inode->i_size = sl->len;
 		inode->i_nlink = 1;
 	}

 done:
 	unlock_new_inode(inode);
 	return inode;
 }
	/* -- linux-c -- --------------------------------------------------------- *
	*
	* drivers/staging/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/mm.h>
	#include <linux/slab.h>
	#include <linux/file.h>
	#include <linux/parser.h>
	#include <linux/bitops.h>
	#include <linux/magic.h>
	#include "autofs_i.h"
	#include <linux/module.h>

	void autofs_kill_sb(struct super_block *sb)
	{
	struct autofs_sb_info *sbi = autofs_sbi(sb);
	unsigned int n;

	/*
	* In the event of a failure in get_sb_nodev the superblock
	* info is not present so nothing else has been setup, so
	* just call kill_anon_super when we are called from
	* deactivate_super.
	*/
	if (!sbi)
	goto out_kill_sb;

	if (!sbi->catatonic)
	autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */

	put_pid(sbi->oz_pgrp);

	autofs_hash_nuke(sbi);
	for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
	if (test_bit(n, sbi->symlink_bitmap))
	kfree(sbi->symlink[n].data);
	}

	kfree(sb->s_fs_info);

	out_kill_sb:
	DPRINTK(("autofs: shutting down\n"));
	kill_anon_super(sb);
	}

	static const struct super_operations autofs_sops = {
	.statfs = simple_statfs,
	.show_options = generic_show_options,
	};

	enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};

	static const match_table_t autofs_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 = task_pgrp_nr(current);

	minproto = maxproto = AUTOFS_PROTO_VERSION;

	*pipefd = -1;

	if (!options)
	return 1;

	while ((p = strsep(&options, ",")) != NULL) {
	int token;
	if (!*p)
	continue;

	token = match_token(p, autofs_tokens, args);
	switch (token) {
	case Opt_fd:
	if (match_int(&args[0], &option))
	return 1;
	*pipefd = option;
	break;
	case Opt_uid:
	if (match_int(&args[0], &option))
	return 1;
	*uid = option;
	break;
	case Opt_gid:
	if (match_int(&args[0], &option))
	return 1;
	*gid = option;
	break;
	case Opt_pgrp:
	if (match_int(&args[0], &option))
	return 1;
	*pgrp = option;
	break;
	case Opt_minproto:
	if (match_int(&args[0], &option))
	return 1;
	*minproto = option;
	break;
	case Opt_maxproto:
	if (match_int(&args[0], &option))
	return 1;
	*maxproto = option;
	break;
	default:
	return 1;
	}
	}
	return (*pipefd < 0);
	}

	int autofs_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;
	int minproto, maxproto;
	pid_t pgid;

	save_mount_options(s, data);

	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	if (!sbi)
	goto fail_unlock;
	DPRINTK(("autofs: starting up, sbi = %p\n",sbi));

	s->s_fs_info = sbi;
	sbi->magic = AUTOFS_SBI_MAGIC;
	sbi->pipe = NULL;
	sbi->catatonic = 1;
	sbi->exp_timeout = 0;
	autofs_initialize_hash(&sbi->dirhash);
	sbi->queues = NULL;
	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
	sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
	s->s_blocksize = 1024;
	s->s_blocksize_bits = 10;
	s->s_magic = AUTOFS_SUPER_MAGIC;
	s->s_op = &autofs_sops;
	s->s_time_gran = 1;
	sbi->sb = s;

	root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
	if (IS_ERR(root_inode))
	goto fail_free;
	root = d_alloc_root(root_inode);
	pipe = NULL;

	if (!root)
	goto fail_iput;

	/* Can this call block? - WTF cares? s is locked. */
	if (parse_options(data, &pipefd, &root_inode->i_uid,
	&root_inode->i_gid, &pgid, &minproto,
	&maxproto)) {
	printk("autofs: called with bogus options\n");
	goto fail_dput;
	}

	/* Couldn't this be tested earlier? */
	if (minproto > AUTOFS_PROTO_VERSION \|\|
	maxproto < AUTOFS_PROTO_VERSION) {
	printk("autofs: kernel does not match daemon version\n");
	goto fail_dput;
	}

	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid));
	sbi->oz_pgrp = find_get_pid(pgid);

	if (!sbi->oz_pgrp) {
	printk("autofs: could not find process group %d\n", pgid);
	goto fail_dput;
	}

	pipe = fget(pipefd);

	if (!pipe) {
	printk("autofs: could not open pipe file descriptor\n");
	goto fail_put_pid;
	}

	if (!pipe->f_op \|\| !pipe->f_op->write)
	goto fail_fput;
	sbi->pipe = pipe;
	sbi->catatonic = 0;

	/*
	* Success! Install the root dentry now to indicate completion.
	*/
	s->s_root = root;
	return 0;

	fail_fput:
	printk("autofs: pipe file descriptor does not contain proper ops\n");
	fput(pipe);
	fail_put_pid:
	put_pid(sbi->oz_pgrp);
	fail_dput:
	dput(root);
	goto fail_free;
	fail_iput:
	printk("autofs: get root dentry failed\n");
	iput(root_inode);
	fail_free:
	kfree(sbi);
	s->s_fs_info = NULL;
	fail_unlock:
	return -EINVAL;
	}

	struct inode autofs_iget(struct super_block sb, unsigned long ino)
	{
	unsigned int n;
	struct autofs_sb_info *sbi = autofs_sbi(sb);
	struct inode *inode;

	inode = iget_locked(sb, ino);
	if (!inode)
	return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
	return inode;

	/* Initialize to the default case (stub directory) */

	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	inode->i_mode = S_IFDIR \| S_IRUGO \| S_IXUGO;
	inode->i_nlink = 2;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;

	if (ino == AUTOFS_ROOT_INO) {
	inode->i_mode = S_IFDIR \| S_IRUGO \| S_IXUGO \| S_IWUSR;
	inode->i_op = &autofs_root_inode_operations;
	inode->i_fop = &autofs_root_operations;
	goto done;
	}

	inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
	inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;

	if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {
	/* Symlink inode - should be in symlink list */
	struct autofs_symlink *sl;

	n = ino - AUTOFS_FIRST_SYMLINK;
	if (n >= AUTOFS_MAX_SYMLINKS \|\| !test_bit(n,sbi->symlink_bitmap)) {
	printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
	goto done;
	}

	inode->i_op = &autofs_symlink_inode_operations;
	sl = &sbi->symlink[n];
	inode->i_private = sl;
	inode->i_mode = S_IFLNK \| S_IRWXUGO;
	inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
	inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
	inode->i_size = sl->len;
	inode->i_nlink = 1;
	}

	done:
	unlock_new_inode(inode);
	return inode;
	}