Commit 7f2da1e7 authored by Al Viro's avatar Al Viro
Browse files

[PATCH] kill altroot 



long overdue...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 8bb79224

fs/namei.c

+2 −87
Original line number Diff line number Diff line
@@ -31,7 +31,6 @@ 
#include <linux/file.h>

#include <linux/fcntl.h>

#include <linux/device_cgroup.h>

#include <asm/namei.h>

#include <asm/uaccess.h>



#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
@@ -562,27 +561,16 @@ out_unlock: 
	return result;

}



static int __emul_lookup_dentry(const char *, struct nameidata *);



/* SMP-safe */

static __always_inline int

static __always_inline void

walk_init_root(const char *name, struct nameidata *nd)

{

	struct fs_struct *fs = current->fs;



	read_lock(&fs->lock);

	if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {

		nd->path = fs->altroot;

		path_get(&fs->altroot);

		read_unlock(&fs->lock);

		if (__emul_lookup_dentry(name,nd))

			return 0;

		read_lock(&fs->lock);

	}

	nd->path = fs->root;

	path_get(&fs->root);

	read_unlock(&fs->lock);

	return 1;

}



/*
@@ -623,12 +611,9 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l 


	if (*link == '/') {

		path_put(&nd->path);

		if (!walk_init_root(link, nd))

			/* weird __emul_prefix() stuff did it */

			goto out;

		walk_init_root(link, nd);

	}

	res = link_path_walk(link, nd);

out:

	if (nd->depth || res || nd->last_type!=LAST_NORM)

		return res;

	/*
@@ -1077,67 +1062,6 @@ static int path_walk(const char *name, struct nameidata *nd) 
	return link_path_walk(name, nd);

}



/* 

 * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if

 * everything is done. Returns 0 and drops input nd, if lookup failed;

 */

static int __emul_lookup_dentry(const char *name, struct nameidata *nd)

{

	if (path_walk(name, nd))

		return 0;		/* something went wrong... */



	if (!nd->path.dentry->d_inode ||

	    S_ISDIR(nd->path.dentry->d_inode->i_mode)) {

		struct path old_path = nd->path;

		struct qstr last = nd->last;

		int last_type = nd->last_type;

		struct fs_struct *fs = current->fs;



		/*

		 * NAME was not found in alternate root or it's a directory.

		 * Try to find it in the normal root:

		 */

		nd->last_type = LAST_ROOT;

		read_lock(&fs->lock);

		nd->path = fs->root;

		path_get(&fs->root);

		read_unlock(&fs->lock);

		if (path_walk(name, nd) == 0) {

			if (nd->path.dentry->d_inode) {

				path_put(&old_path);

				return 1;

			}

			path_put(&nd->path);

		}

		nd->path = old_path;

		nd->last = last;

		nd->last_type = last_type;

	}

	return 1;

}



void set_fs_altroot(void)

{

	char *emul = __emul_prefix();

	struct nameidata nd;

	struct path path = {}, old_path;

	int err;

	struct fs_struct *fs = current->fs;



	if (!emul)

		goto set_it;

	err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd);

	if (!err)

		path = nd.path;

set_it:

	write_lock(&fs->lock);

	old_path = fs->altroot;

	fs->altroot = path;

	write_unlock(&fs->lock);

	if (old_path.dentry)

		path_put(&old_path);

}



/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */

static int do_path_lookup(int dfd, const char *name,

				unsigned int flags, struct nameidata *nd)
@@ -1153,14 +1077,6 @@ static int do_path_lookup(int dfd, const char *name, 


	if (*name=='/') {

		read_lock(&fs->lock);

		if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {

			nd->path = fs->altroot;

			path_get(&fs->altroot);

			read_unlock(&fs->lock);

			if (__emul_lookup_dentry(name,nd))

				goto out; /* found in altroot */

			read_lock(&fs->lock);

		}

		nd->path = fs->root;

		path_get(&fs->root);

		read_unlock(&fs->lock);
@@ -1194,7 +1110,6 @@ static int do_path_lookup(int dfd, const char *name, 
	}



	retval = path_walk(name, nd);

out:

	if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&

				nd->path.dentry->d_inode))

		audit_inode(name, nd->path.dentry);

fs/namespace.c

+1 −7
Original line number Diff line number Diff line
@@ -1972,7 +1972,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, 
		struct fs_struct *fs)

{

	struct mnt_namespace *new_ns;

	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL;

	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;

	struct vfsmount *p, *q;



	new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
@@ -2015,10 +2015,6 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, 
				pwdmnt = p;

				fs->pwd.mnt = mntget(q);

			}

			if (p == fs->altroot.mnt) {

				altrootmnt = p;

				fs->altroot.mnt = mntget(q);

			}

		}

		p = next_mnt(p, mnt_ns->root);

		q = next_mnt(q, new_ns->root);
@@ -2029,8 +2025,6 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, 
		mntput(rootmnt);

	if (pwdmnt)

		mntput(pwdmnt);

	if (altrootmnt)

		mntput(altrootmnt);



	return new_ns;

}

fs/open.c

+1 −2
Original line number Diff line number Diff line
@@ -548,7 +548,7 @@ asmlinkage long sys_chroot(const char __user * filename) 
	struct nameidata nd;

	int error;



	error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);

	error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);

	if (error)

		goto out;
@@ -561,7 +561,6 @@ asmlinkage long sys_chroot(const char __user * filename) 
		goto dput_and_out;



	set_fs_root(current->fs, &nd.path);

	set_fs_altroot();

	error = 0;

dput_and_out:

	path_put(&nd.path);

include/asm-alpha/namei.h

deleted100644 → 0
+0 −17
Original line number Diff line number Diff line 
/* $Id: namei.h,v 1.1 1996/12/13 14:48:21 jj Exp $

 * linux/include/asm-alpha/namei.h

 *

 * Included from linux/fs/namei.c

 */



#ifndef __ALPHA_NAMEI_H

#define __ALPHA_NAMEI_H



/* This dummy routine maybe changed to something useful

 * for /usr/gnemul/ emulation stuff.

 * Look at asm-sparc/namei.h for details.

 */



#define __emul_prefix() NULL



#endif /* __ALPHA_NAMEI_H */

include/asm-arm/namei.h

deleted100644 → 0
+0 −25
Original line number Diff line number Diff line 
/* 

 * linux/include/asm-arm/namei.h

 *

 * Routines to handle famous /usr/gnemul

 * Derived from the Sparc version of this file

 *

 * Included from linux/fs/namei.c

 */



#ifndef __ASMARM_NAMEI_H

#define __ASMARM_NAMEI_H



#define ARM_BSD_EMUL "usr/gnemul/bsd/"



static inline char *__emul_prefix(void)

{

	switch (current->personality) {

	case PER_BSD:

		return ARM_BSD_EMUL;

	default:

		return NULL;

	}

}



#endif /* __ASMARM_NAMEI_H */

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