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[PATCH] kill altroot

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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/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);