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Commit 34ca959c authored by Ian Kent's avatar Ian Kent Committed by Linus Torvalds
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[PATCH] autofs4: add v5 follow_link mount trigger method 



This patch adds a follow_link inode method for the root of an autofs direct
mount trigger.  It also adds the corresponding mount options and updates the
show_mount method.

Signed-off-by: default avatarIan Kent <raven@themaw.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 051d3812

fs/autofs4/autofs_i.h

+8 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * linux/fs/autofs/autofs_i.h

 *

 *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved

 *   Copyright 2005-2006 Ian Kent <raven@themaw.net>

 *

 * 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
@@ -84,6 +85,10 @@ struct autofs_wait_queue { 


#define AUTOFS_SBI_MAGIC 0x6d4a556d



#define AUTOFS_TYP_INDIRECT     0x0001

#define AUTOFS_TYP_DIRECT       0x0002

#define AUTOFS_TYP_OFFSET       0x0004



struct autofs_sb_info {

	u32 magic;

	struct dentry *root;
@@ -96,6 +101,7 @@ struct autofs_sb_info { 
	int min_proto;

	int max_proto;

	unsigned long exp_timeout;

	unsigned int type;

	int reghost_enabled;

	int needs_reghost;

	struct super_block *sb;
@@ -162,6 +168,8 @@ int autofs4_expire_multi(struct super_block *, struct vfsmount *, 
extern struct inode_operations autofs4_symlink_inode_operations;

extern struct inode_operations autofs4_dir_inode_operations;

extern struct inode_operations autofs4_root_inode_operations;

extern struct inode_operations autofs4_indirect_root_inode_operations;

extern struct inode_operations autofs4_direct_root_inode_operations;

extern struct file_operations autofs4_dir_operations;

extern struct file_operations autofs4_root_operations;

fs/autofs4/inode.c

+43 −9
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * linux/fs/autofs/inode.c

 *

 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved

 *  Copyright 2005-2006 Ian Kent <raven@themaw.net>

 *

 * 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
@@ -177,6 +178,13 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) 
	seq_printf(m, ",minproto=%d", sbi->min_proto);

	seq_printf(m, ",maxproto=%d", sbi->max_proto);



	if (sbi->type & AUTOFS_TYP_OFFSET)

		seq_printf(m, ",offset");

	else if (sbi->type & AUTOFS_TYP_DIRECT)

		seq_printf(m, ",direct");

	else

		seq_printf(m, ",indirect");



	return 0;

}
@@ -186,7 +194,8 @@ static struct super_operations autofs4_sops = { 
	.show_options	= autofs4_show_options,

};



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

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

	Opt_indirect, Opt_direct, Opt_offset};



static match_table_t tokens = {

	{Opt_fd, "fd=%u"},
@@ -195,11 +204,15 @@ static match_table_t tokens = { 
	{Opt_pgrp, "pgrp=%u"},

	{Opt_minproto, "minproto=%u"},

	{Opt_maxproto, "maxproto=%u"},

	{Opt_indirect, "indirect"},

	{Opt_direct, "direct"},

	{Opt_offset, "offset"},

	{Opt_err, NULL}

};



static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,

			 pid_t *pgrp, int *minproto, int *maxproto)

			 pid_t *pgrp, unsigned int *type,

			 int *minproto, int *maxproto)

{

	char *p;

	substring_t args[MAX_OPT_ARGS];
@@ -253,6 +266,15 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, 
				return 1;

			*maxproto = option;

			break;

		case Opt_indirect:

			*type = AUTOFS_TYP_INDIRECT;

			break;

		case Opt_direct:

			*type = AUTOFS_TYP_DIRECT;

			break;

		case Opt_offset:

			*type = AUTOFS_TYP_DIRECT | AUTOFS_TYP_OFFSET;

			break;

		default:

			return 1;

		}
@@ -271,6 +293,11 @@ static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) 
	return ino;

}



void autofs4_dentry_release(struct dentry *);

static struct dentry_operations autofs4_sb_dentry_operations = {

	.d_release      = autofs4_dentry_release,

};



int autofs4_fill_super(struct super_block *s, void *data, int silent)

{

	struct inode * root_inode;
@@ -297,6 +324,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) 
	sbi->sb = s;

	sbi->version = 0;

	sbi->sub_version = 0;

	sbi->type = 0;

	sbi->min_proto = 0;

	sbi->max_proto = 0;

	mutex_init(&sbi->wq_mutex);
@@ -315,27 +343,31 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) 
	if (!ino)

		goto fail_free;

	root_inode = autofs4_get_inode(s, ino);

	kfree(ino);

	if (!root_inode)

		goto fail_free;

		goto fail_ino;



	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;

	pipe = NULL;



	root->d_op = &autofs4_sb_dentry_operations;

	root->d_fsdata = ino;



	/* Can this call block? */

	if (parse_options(data, &pipefd,

			  &root_inode->i_uid, &root_inode->i_gid,

			  &sbi->oz_pgrp,

			  &sbi->oz_pgrp, &sbi->type,

			  &sbi->min_proto, &sbi->max_proto)) {

		printk("autofs: called with bogus options\n");

		goto fail_dput;

	}



	root_inode->i_fop = &autofs4_root_operations;

	root_inode->i_op = sbi->type & AUTOFS_TYP_DIRECT ?

			&autofs4_direct_root_inode_operations :

			&autofs4_indirect_root_inode_operations;



	/* Couldn't this be tested earlier? */

	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||

	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
@@ -391,6 +423,8 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) 
fail_iput:

	printk("autofs: get root dentry failed\n");

	iput(root_inode);

fail_ino:

	kfree(ino);

fail_free:

	kfree(sbi);

fail_unlock:

fs/autofs4/root.c

+52 −12
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 *

 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved

 *  Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>

 *  Copyright 2001-2003 Ian Kent <raven@themaw.net>

 *  Copyright 2001-2006 Ian Kent <raven@themaw.net>

 *

 * 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
@@ -30,6 +30,7 @@ static int autofs4_dir_close(struct inode *inode, struct file *file); 
static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);

static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);

static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);

static void *autofs4_follow_link(struct dentry *, struct nameidata *);



struct file_operations autofs4_root_operations = {

	.open		= dcache_dir_open,
@@ -46,7 +47,7 @@ struct file_operations autofs4_dir_operations = { 
	.readdir	= autofs4_dir_readdir,

};



struct inode_operations autofs4_root_inode_operations = {

struct inode_operations autofs4_indirect_root_inode_operations = {

	.lookup		= autofs4_lookup,

	.unlink		= autofs4_dir_unlink,

	.symlink	= autofs4_dir_symlink,
@@ -54,6 +55,11 @@ struct inode_operations autofs4_root_inode_operations = { 
	.rmdir		= autofs4_dir_rmdir,

};



struct inode_operations autofs4_direct_root_inode_operations = {

	.lookup		= autofs4_lookup,

	.follow_link	= autofs4_follow_link,

};



struct inode_operations autofs4_dir_inode_operations = {

	.lookup		= autofs4_lookup,

	.unlink		= autofs4_dir_unlink,
@@ -252,7 +258,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 
		 */

		status = d_invalidate(dentry);

		if (status != -EBUSY)

			return 0;

			return -ENOENT;

	}



	DPRINTK("dentry=%p %.*s ino=%p",
@@ -271,17 +277,17 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 
		DPRINTK("mount done status=%d", status);



		if (status && dentry->d_inode)

			return 0; /* Try to get the kernel to invalidate this dentry */

			return status; /* Try to get the kernel to invalidate this dentry */



		/* Turn this into a real negative dentry? */

		if (status == -ENOENT) {

			spin_lock(&dentry->d_lock);

			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;

			spin_unlock(&dentry->d_lock);

			return 0;

			return status;

		} else if (status) {

			/* Return a negative dentry, but leave it "pending" */

			return 0;

			return status;

		}

	/* Trigger mount for path component or follow link */

	} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
@@ -300,7 +306,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 
			spin_lock(&dentry->d_lock);

			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;

			spin_unlock(&dentry->d_lock);

			return 0;

			return status;

		}

	}
@@ -311,7 +317,41 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 
	spin_lock(&dentry->d_lock);

	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;

	spin_unlock(&dentry->d_lock);

	return 1;

	return status;

}



/* For autofs direct mounts the follow link triggers the mount */

static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)

{

	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);

	int oz_mode = autofs4_oz_mode(sbi);

	unsigned int lookup_type;

	int status;



	DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",

		dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,

		nd->flags);



	/* If it's our master or we shouldn't trigger a mount we're done */

	lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);

	if (oz_mode || !lookup_type)

		goto done;



	status = try_to_fill_dentry(dentry, 0);

	if (status)

		goto out_error;



	if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {

		status = -ENOENT;

		goto out_error;

	}



done:

	return NULL;



out_error:

	path_release(nd);

	return ERR_PTR(status);

}



/*
@@ -326,13 +366,13 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 
	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);

	int oz_mode = autofs4_oz_mode(sbi);

	int flags = nd ? nd->flags : 0;

	int status = 1;

	int status = 0;



	/* Pending dentry */

	if (autofs4_ispending(dentry)) {

		if (!oz_mode)

			status = try_to_fill_dentry(dentry, flags);

		return status;

		return !status;

	}



	/* Negative dentry.. invalidate if "old" */
@@ -349,14 +389,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 
		spin_unlock(&dcache_lock);

		if (!oz_mode)

			status = try_to_fill_dentry(dentry, flags);

		return status;

		return !status;

	}

	spin_unlock(&dcache_lock);



	return 1;

}



static void autofs4_dentry_release(struct dentry *de)

void autofs4_dentry_release(struct dentry *de)

{

	struct autofs_info *inf;