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OpenCloudOS-Kernel
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[PATCH] kill altroot 

long overdue...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2008-05-10 20:44:54 -04:00
parent 8bb79224b8
commit 7f2da1e7d0
31 changed files with 5 additions and 466 deletions
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89
fs/namei.c
View File

@ -31,7 +31,6 @@
#include <linux/file.h> #include <linux/file.h>
#include <linux/fcntl.h> #include <linux/fcntl.h>
#include <linux/device_cgroup.h> #include <linux/device_cgroup.h>
#include <asm/namei.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
@ -562,27 +561,16 @@ out_unlock:
return result; return result;
} }
static int __emul_lookup_dentry(const char *, struct nameidata *);
/* SMP-safe */ /* SMP-safe */
static __always_inline int static __always_inline void
walk_init_root(const char *name, struct nameidata *nd) walk_init_root(const char *name, struct nameidata *nd)
{ {
struct fs_struct *fs = current->fs; struct fs_struct *fs = current->fs;
read_lock(&fs->lock); 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; nd->path = fs->root;
path_get(&fs->root); path_get(&fs->root);
read_unlock(&fs->lock); 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 == '/') { if (*link == '/') {
path_put(&nd->path); path_put(&nd->path);
if (!walk_init_root(link, nd)) walk_init_root(link, nd);
/* weird __emul_prefix() stuff did it */
goto out;
} }
res = link_path_walk(link, nd); res = link_path_walk(link, nd);
out:
if (nd->depth || res || nd->last_type!=LAST_NORM) if (nd->depth || res || nd->last_type!=LAST_NORM)
return res; return res;
/* /*
@ -1077,67 +1062,6 @@ static int path_walk(const char *name, struct nameidata *nd)
return link_path_walk(name, 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. */ /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
static int do_path_lookup(int dfd, const char *name, static int do_path_lookup(int dfd, const char *name,
unsigned int flags, struct nameidata *nd) unsigned int flags, struct nameidata *nd)
@ -1153,14 +1077,6 @@ static int do_path_lookup(int dfd, const char *name,
if (*name=='/') { if (*name=='/') {
read_lock(&fs->lock); 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; nd->path = fs->root;
path_get(&fs->root); path_get(&fs->root);
read_unlock(&fs->lock); read_unlock(&fs->lock);
@ -1194,7 +1110,6 @@ static int do_path_lookup(int dfd, const char *name,
} }
retval = path_walk(name, nd); retval = path_walk(name, nd);
out:
if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
nd->path.dentry->d_inode)) nd->path.dentry->d_inode))
audit_inode(name, nd->path.dentry); audit_inode(name, nd->path.dentry);

8
fs/namespace.c
View File

@ -1972,7 +1972,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
struct fs_struct *fs) struct fs_struct *fs)
{ {
struct mnt_namespace *new_ns; struct mnt_namespace *new_ns;
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
struct vfsmount *p, *q; struct vfsmount *p, *q;
new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); 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; pwdmnt = p;
fs->pwd.mnt = mntget(q); fs->pwd.mnt = mntget(q);
} }
if (p == fs->altroot.mnt) {
altrootmnt = p;
fs->altroot.mnt = mntget(q);
}
} }
p = next_mnt(p, mnt_ns->root); p = next_mnt(p, mnt_ns->root);
q = next_mnt(q, new_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); mntput(rootmnt);
if (pwdmnt) if (pwdmnt)
mntput(pwdmnt); mntput(pwdmnt);
if (altrootmnt)
mntput(altrootmnt);
return new_ns; return new_ns;
} }

3
fs/open.c
View File

@ -548,7 +548,7 @@ asmlinkage long sys_chroot(const char __user * filename)
struct nameidata nd; struct nameidata nd;
int error; int error;
error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
if (error) if (error)
goto out; goto out;
@ -561,7 +561,6 @@ asmlinkage long sys_chroot(const char __user * filename)
goto dput_and_out; goto dput_and_out;
set_fs_root(current->fs, &nd.path); set_fs_root(current->fs, &nd.path);
set_fs_altroot();
error = 0; error = 0;
dput_and_out: dput_and_out:
path_put(&nd.path); path_put(&nd.path);

17
include/asm-alpha/namei.h
View File

@ -1,17 +0,0 @@
/* $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 */

25
include/asm-arm/namei.h
View File

@ -1,25 +0,0 @@
/*
* 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 */

7
include/asm-avr32/namei.h
View File

@ -1,7 +0,0 @@
#ifndef __ASM_AVR32_NAMEI_H
#define __ASM_AVR32_NAMEI_H
/* This dummy routine may be changed to something useful */
#define __emul_prefix() NULL
#endif /* __ASM_AVR32_NAMEI_H */

19
include/asm-blackfin/namei.h
View File

@ -1,19 +0,0 @@
/*
* linux/include/asm/namei.h
*
* Included from linux/fs/namei.c
*
* Changes made by Lineo Inc. May 2001
*/
#ifndef __BFIN_NAMEI_H
#define __BFIN_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

17
include/asm-cris/namei.h
View File

@ -1,17 +0,0 @@
/* $Id: namei.h,v 1.1 2000/07/10 16:32:31 bjornw Exp $
* linux/include/asm-cris/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __CRIS_NAMEI_H
#define __CRIS_NAMEI_H
/* used to find file-system prefixes for doing emulations
* see for example asm-sparc/namei.h
* we don't use it...
*/
#define __emul_prefix() NULL
#endif /* __CRIS_NAMEI_H */

18
include/asm-frv/namei.h
View File

@ -1,18 +0,0 @@
/*
* include/asm-frv/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __ASM_NAMEI_H
#define __ASM_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

17
include/asm-h8300/namei.h
View File

@ -1,17 +0,0 @@
/*
* linux/include/asm-h8300/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __H8300_NAMEI_H
#define __H8300_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

25
include/asm-ia64/namei.h
View File

@ -1,25 +0,0 @@
#ifndef _ASM_IA64_NAMEI_H
#define _ASM_IA64_NAMEI_H
/*
* Modified 1998, 1999, 2001
* David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
*/
#include <asm/ptrace.h>
#include <asm/system.h>
#define EMUL_PREFIX_LINUX_IA32 "/emul/ia32-linux/"
static inline char *
__emul_prefix (void)
{
switch (current->personality) {
case PER_LINUX32:
return EMUL_PREFIX_LINUX_IA32;
default:
return NULL;
}
}
#endif /* _ASM_IA64_NAMEI_H */

17
include/asm-m32r/namei.h
View File

@ -1,17 +0,0 @@
#ifndef _ASM_M32R_NAMEI_H
#define _ASM_M32R_NAMEI_H
/*
* linux/include/asm-m32r/namei.h
*
* Included from linux/fs/namei.c
*/
/* 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 /* _ASM_M32R_NAMEI_H */

17
include/asm-m68k/namei.h
View File

@ -1,17 +0,0 @@
/*
* linux/include/asm-m68k/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __M68K_NAMEI_H
#define __M68K_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

1
include/asm-m68knommu/namei.h
View File

@ -1 +0,0 @@
#include <asm-m68k/namei.h>

11
include/asm-mips/namei.h
View File

@ -1,11 +0,0 @@
#ifndef _ASM_NAMEI_H
#define _ASM_NAMEI_H
/*
* This dummy routine maybe changed to something useful
* for /usr/gnemul/ emulation stuff.
*/
#define __emul_prefix() NULL
#endif /* _ASM_NAMEI_H */

22
include/asm-mn10300/namei.h
View File

@ -1,22 +0,0 @@
/* Emulation stuff
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_NAMEI_H
#define _ASM_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 /* _ASM_NAMEI_H */

17
include/asm-parisc/namei.h
View File

@ -1,17 +0,0 @@
/* $Id: namei.h,v 1.1 1996/12/13 14:48:21 jj Exp $
* linux/include/asm-parisc/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __PARISC_NAMEI_H
#define __PARISC_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 /* __PARISC_NAMEI_H */

20
include/asm-powerpc/namei.h
View File

@ -1,20 +0,0 @@
#ifndef _ASM_POWERPC_NAMEI_H
#define _ASM_POWERPC_NAMEI_H
#ifdef __KERNEL__
/*
* Adapted from include/asm-alpha/namei.h
*
* Included from fs/namei.c
*/
/* 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 /* __KERNEL__ */
#endif /* _ASM_POWERPC_NAMEI_H */

21
include/asm-s390/namei.h
View File

@ -1,21 +0,0 @@
/*
* include/asm-s390/namei.h
*
* S390 version
*
* Derived from "include/asm-i386/namei.h"
*
* Included from linux/fs/namei.c
*/
#ifndef __S390_NAMEI_H
#define __S390_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 /* __S390_NAMEI_H */

17
include/asm-sh/namei.h
View File

@ -1,17 +0,0 @@
/* $Id: namei.h,v 1.3 2000/07/04 06:24:49 gniibe Exp $
* linux/include/asm-sh/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __ASM_SH_NAMEI_H
#define __ASM_SH_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 /* __ASM_SH_NAMEI_H */

8
include/asm-sparc/namei.h
View File

@ -1,8 +0,0 @@
#ifndef ___ASM_SPARC_NAMEI_H
#define ___ASM_SPARC_NAMEI_H
#if defined(__sparc__) && defined(__arch64__)
#include <asm-sparc/namei_64.h>
#else
#include <asm-sparc/namei_32.h>
#endif
#endif

1
include/asm-sparc64/namei.h
View File

@ -1 +0,0 @@
#include <asm-sparc/namei.h>

6
include/asm-um/namei.h
View File

@ -1,6 +0,0 @@
#ifndef __UM_NAMEI_H
#define __UM_NAMEI_H
#include "asm/arch/namei.h"
#endif

17
include/asm-v850/namei.h
View File

@ -1,17 +0,0 @@
/*
* linux/include/asm-v850/namei.h
*
* Included from linux/fs/namei.c
*/
#ifndef __V850_NAMEI_H__
#define __V850_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 /* __V850_NAMEI_H__ */

11
include/asm-x86/namei.h
View File

@ -1,11 +0,0 @@
#ifndef _ASM_X86_NAMEI_H
#define _ASM_X86_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 /* _ASM_X86_NAMEI_H */

26
include/asm-xtensa/namei.h
View File

@ -1,26 +0,0 @@
/*
* include/asm-xtensa/namei.h
*
* Included from linux/fs/namei.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_NAMEI_H
#define _XTENSA_NAMEI_H
#ifdef __KERNEL__
/* 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 /* __KERNEL__ */
#endif /* _XTENSA_NAMEI_H */

3
include/linux/fs_struct.h
View File

@ -7,7 +7,7 @@ struct fs_struct {
atomic_t count; atomic_t count;
rwlock_t lock; rwlock_t lock;
int umask; int umask;
struct path root, pwd, altroot; struct path root, pwd;
}; };
#define INIT_FS { \ #define INIT_FS { \
@ -19,7 +19,6 @@ struct fs_struct {
extern struct kmem_cache *fs_cachep; extern struct kmem_cache *fs_cachep;
extern void exit_fs(struct task_struct *); extern void exit_fs(struct task_struct *);
extern void set_fs_altroot(void);
extern void set_fs_root(struct fs_struct *, struct path *); extern void set_fs_root(struct fs_struct *, struct path *);
extern void set_fs_pwd(struct fs_struct *, struct path *); extern void set_fs_pwd(struct fs_struct *, struct path *);
extern struct fs_struct *copy_fs_struct(struct fs_struct *); extern struct fs_struct *copy_fs_struct(struct fs_struct *);

1
include/linux/namei.h
View File

@ -47,7 +47,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
#define LOOKUP_DIRECTORY 2 #define LOOKUP_DIRECTORY 2
#define LOOKUP_CONTINUE 4 #define LOOKUP_CONTINUE 4
#define LOOKUP_PARENT 16 #define LOOKUP_PARENT 16
#define LOOKUP_NOALT 32
#define LOOKUP_REVAL 64 #define LOOKUP_REVAL 64
/* /*
* Intent data * Intent data

1
kernel/exec_domain.c
View File

@ -168,7 +168,6 @@ __set_personality(u_long personality)
current->personality = personality; current->personality = personality;
oep = current_thread_info()->exec_domain; oep = current_thread_info()->exec_domain;
current_thread_info()->exec_domain = ep; current_thread_info()->exec_domain = ep;
set_fs_altroot();
module_put(oep->module); module_put(oep->module);
return 0; return 0;

2
kernel/exit.c
View File

@ -565,8 +565,6 @@ void put_fs_struct(struct fs_struct *fs)
if (atomic_dec_and_test(&fs->count)) { if (atomic_dec_and_test(&fs->count)) {
path_put(&fs->root); path_put(&fs->root);
path_put(&fs->pwd); path_put(&fs->pwd);
if (fs->altroot.dentry)
path_put(&fs->altroot);
kmem_cache_free(fs_cachep, fs); kmem_cache_free(fs_cachep, fs);
} }
} }

7
kernel/fork.c
View File

@ -657,13 +657,6 @@ static struct fs_struct *__copy_fs_struct(struct fs_struct *old)
path_get(&old->root); path_get(&old->root);
fs->pwd = old->pwd; fs->pwd = old->pwd;
path_get(&old->pwd); path_get(&old->pwd);
if (old->altroot.dentry) {
fs->altroot = old->altroot;
path_get(&old->altroot);
} else {
fs->altroot.mnt = NULL;
fs->altroot.dentry = NULL;
}
read_unlock(&old->lock); read_unlock(&old->lock);
} }
return fs; return fs;