Embed a struct path into struct nameidata instead of nd->{dentry,mnt}
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.
Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
<dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
struct path in every place where the stack can be traversed
- it reduces the overall code size:
without patch series:
text data bss dec hex filename
5321639 858418 715768 6895825 6938d1 vmlinux
with patch series:
text data bss dec hex filename
5320026 858418 715768 6894212 693284 vmlinux
This patch:
Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/namespace.c b/fs/namespace.c
index 7937d30..5d9fd4c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -157,13 +157,13 @@
static void detach_mnt(struct vfsmount *mnt, struct nameidata *old_nd)
{
- old_nd->dentry = mnt->mnt_mountpoint;
- old_nd->mnt = mnt->mnt_parent;
+ old_nd->path.dentry = mnt->mnt_mountpoint;
+ old_nd->path.mnt = mnt->mnt_parent;
mnt->mnt_parent = mnt;
mnt->mnt_mountpoint = mnt->mnt_root;
list_del_init(&mnt->mnt_child);
list_del_init(&mnt->mnt_hash);
- old_nd->dentry->d_mounted--;
+ old_nd->path.dentry->d_mounted--;
}
void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry,
@@ -176,10 +176,10 @@
static void attach_mnt(struct vfsmount *mnt, struct nameidata *nd)
{
- mnt_set_mountpoint(nd->mnt, nd->dentry, mnt);
+ mnt_set_mountpoint(nd->path.mnt, nd->path.dentry, mnt);
list_add_tail(&mnt->mnt_hash, mount_hashtable +
- hash(nd->mnt, nd->dentry));
- list_add_tail(&mnt->mnt_child, &nd->mnt->mnt_mounts);
+ hash(nd->path.mnt, nd->path.dentry));
+ list_add_tail(&mnt->mnt_child, &nd->path.mnt->mnt_mounts);
}
/*
@@ -679,20 +679,20 @@
if (retval)
goto out;
retval = -EINVAL;
- if (nd.dentry != nd.mnt->mnt_root)
+ if (nd.path.dentry != nd.path.mnt->mnt_root)
goto dput_and_out;
- if (!check_mnt(nd.mnt))
+ if (!check_mnt(nd.path.mnt))
goto dput_and_out;
retval = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto dput_and_out;
- retval = do_umount(nd.mnt, flags);
+ retval = do_umount(nd.path.mnt, flags);
dput_and_out:
/* we mustn't call path_put() as that would clear mnt_expiry_mark */
- dput(nd.dentry);
- mntput_no_expire(nd.mnt);
+ dput(nd.path.dentry);
+ mntput_no_expire(nd.path.mnt);
out:
return retval;
}
@@ -715,10 +715,10 @@
return 0;
return -EPERM;
#ifdef notyet
- if (S_ISLNK(nd->dentry->d_inode->i_mode))
+ if (S_ISLNK(nd->path.dentry->d_inode->i_mode))
return -EPERM;
- if (nd->dentry->d_inode->i_mode & S_ISVTX) {
- if (current->uid != nd->dentry->d_inode->i_uid)
+ if (nd->path.dentry->d_inode->i_mode & S_ISVTX) {
+ if (current->uid != nd->path.dentry->d_inode->i_uid)
return -EPERM;
}
if (vfs_permission(nd, MAY_WRITE))
@@ -767,8 +767,8 @@
q = q->mnt_parent;
}
p = s;
- nd.mnt = q;
- nd.dentry = p->mnt_mountpoint;
+ nd.path.mnt = q;
+ nd.path.dentry = p->mnt_mountpoint;
q = clone_mnt(p, p->mnt_root, flag);
if (!q)
goto Enomem;
@@ -877,8 +877,8 @@
struct nameidata *nd, struct nameidata *parent_nd)
{
LIST_HEAD(tree_list);
- struct vfsmount *dest_mnt = nd->mnt;
- struct dentry *dest_dentry = nd->dentry;
+ struct vfsmount *dest_mnt = nd->path.mnt;
+ struct dentry *dest_dentry = nd->path.dentry;
struct vfsmount *child, *p;
if (propagate_mnt(dest_mnt, dest_dentry, source_mnt, &tree_list))
@@ -913,13 +913,13 @@
if (mnt->mnt_sb->s_flags & MS_NOUSER)
return -EINVAL;
- if (S_ISDIR(nd->dentry->d_inode->i_mode) !=
+ if (S_ISDIR(nd->path.dentry->d_inode->i_mode) !=
S_ISDIR(mnt->mnt_root->d_inode->i_mode))
return -ENOTDIR;
err = -ENOENT;
- mutex_lock(&nd->dentry->d_inode->i_mutex);
- if (IS_DEADDIR(nd->dentry->d_inode))
+ mutex_lock(&nd->path.dentry->d_inode->i_mutex);
+ if (IS_DEADDIR(nd->path.dentry->d_inode))
goto out_unlock;
err = security_sb_check_sb(mnt, nd);
@@ -927,10 +927,10 @@
goto out_unlock;
err = -ENOENT;
- if (IS_ROOT(nd->dentry) || !d_unhashed(nd->dentry))
+ if (IS_ROOT(nd->path.dentry) || !d_unhashed(nd->path.dentry))
err = attach_recursive_mnt(mnt, nd, NULL);
out_unlock:
- mutex_unlock(&nd->dentry->d_inode->i_mutex);
+ mutex_unlock(&nd->path.dentry->d_inode->i_mutex);
if (!err)
security_sb_post_addmount(mnt, nd);
return err;
@@ -942,14 +942,14 @@
*/
static noinline int do_change_type(struct nameidata *nd, int flag)
{
- struct vfsmount *m, *mnt = nd->mnt;
+ struct vfsmount *m, *mnt = nd->path.mnt;
int recurse = flag & MS_REC;
int type = flag & ~MS_REC;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (nd->dentry != nd->mnt->mnt_root)
+ if (nd->path.dentry != nd->path.mnt->mnt_root)
return -EINVAL;
down_write(&namespace_sem);
@@ -981,17 +981,17 @@
down_write(&namespace_sem);
err = -EINVAL;
- if (IS_MNT_UNBINDABLE(old_nd.mnt))
- goto out;
+ if (IS_MNT_UNBINDABLE(old_nd.path.mnt))
+ goto out;
- if (!check_mnt(nd->mnt) || !check_mnt(old_nd.mnt))
+ if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt))
goto out;
err = -ENOMEM;
if (recurse)
- mnt = copy_tree(old_nd.mnt, old_nd.dentry, 0);
+ mnt = copy_tree(old_nd.path.mnt, old_nd.path.dentry, 0);
else
- mnt = clone_mnt(old_nd.mnt, old_nd.dentry, 0);
+ mnt = clone_mnt(old_nd.path.mnt, old_nd.path.dentry, 0);
if (!mnt)
goto out;
@@ -1021,24 +1021,24 @@
void *data)
{
int err;
- struct super_block *sb = nd->mnt->mnt_sb;
+ struct super_block *sb = nd->path.mnt->mnt_sb;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!check_mnt(nd->mnt))
+ if (!check_mnt(nd->path.mnt))
return -EINVAL;
- if (nd->dentry != nd->mnt->mnt_root)
+ if (nd->path.dentry != nd->path.mnt->mnt_root)
return -EINVAL;
down_write(&sb->s_umount);
err = do_remount_sb(sb, flags, data, 0);
if (!err)
- nd->mnt->mnt_flags = mnt_flags;
+ nd->path.mnt->mnt_flags = mnt_flags;
up_write(&sb->s_umount);
if (!err)
- security_sb_post_remount(nd->mnt, flags, data);
+ security_sb_post_remount(nd->path.mnt, flags, data);
return err;
}
@@ -1069,56 +1069,60 @@
return err;
down_write(&namespace_sem);
- while (d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry))
+ while (d_mountpoint(nd->path.dentry) &&
+ follow_down(&nd->path.mnt, &nd->path.dentry))
;
err = -EINVAL;
- if (!check_mnt(nd->mnt) || !check_mnt(old_nd.mnt))
+ if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt))
goto out;
err = -ENOENT;
- mutex_lock(&nd->dentry->d_inode->i_mutex);
- if (IS_DEADDIR(nd->dentry->d_inode))
+ mutex_lock(&nd->path.dentry->d_inode->i_mutex);
+ if (IS_DEADDIR(nd->path.dentry->d_inode))
goto out1;
- if (!IS_ROOT(nd->dentry) && d_unhashed(nd->dentry))
+ if (!IS_ROOT(nd->path.dentry) && d_unhashed(nd->path.dentry))
goto out1;
err = -EINVAL;
- if (old_nd.dentry != old_nd.mnt->mnt_root)
+ if (old_nd.path.dentry != old_nd.path.mnt->mnt_root)
goto out1;
- if (old_nd.mnt == old_nd.mnt->mnt_parent)
+ if (old_nd.path.mnt == old_nd.path.mnt->mnt_parent)
goto out1;
- if (S_ISDIR(nd->dentry->d_inode->i_mode) !=
- S_ISDIR(old_nd.dentry->d_inode->i_mode))
+ if (S_ISDIR(nd->path.dentry->d_inode->i_mode) !=
+ S_ISDIR(old_nd.path.dentry->d_inode->i_mode))
goto out1;
/*
* Don't move a mount residing in a shared parent.
*/
- if (old_nd.mnt->mnt_parent && IS_MNT_SHARED(old_nd.mnt->mnt_parent))
+ if (old_nd.path.mnt->mnt_parent &&
+ IS_MNT_SHARED(old_nd.path.mnt->mnt_parent))
goto out1;
/*
* Don't move a mount tree containing unbindable mounts to a destination
* mount which is shared.
*/
- if (IS_MNT_SHARED(nd->mnt) && tree_contains_unbindable(old_nd.mnt))
+ if (IS_MNT_SHARED(nd->path.mnt) &&
+ tree_contains_unbindable(old_nd.path.mnt))
goto out1;
err = -ELOOP;
- for (p = nd->mnt; p->mnt_parent != p; p = p->mnt_parent)
- if (p == old_nd.mnt)
+ for (p = nd->path.mnt; p->mnt_parent != p; p = p->mnt_parent)
+ if (p == old_nd.path.mnt)
goto out1;
- if ((err = attach_recursive_mnt(old_nd.mnt, nd, &parent_nd)))
+ err = attach_recursive_mnt(old_nd.path.mnt, nd, &parent_nd);
+ if (err)
goto out1;
spin_lock(&vfsmount_lock);
/* if the mount is moved, it should no longer be expire
* automatically */
- list_del_init(&old_nd.mnt->mnt_expire);
+ list_del_init(&old_nd.path.mnt->mnt_expire);
spin_unlock(&vfsmount_lock);
out1:
- mutex_unlock(&nd->dentry->d_inode->i_mutex);
+ mutex_unlock(&nd->path.dentry->d_inode->i_mutex);
out:
up_write(&namespace_sem);
if (!err)
@@ -1162,16 +1166,17 @@
down_write(&namespace_sem);
/* Something was mounted here while we slept */
- while (d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry))
+ while (d_mountpoint(nd->path.dentry) &&
+ follow_down(&nd->path.mnt, &nd->path.dentry))
;
err = -EINVAL;
- if (!check_mnt(nd->mnt))
+ if (!check_mnt(nd->path.mnt))
goto unlock;
/* Refuse the same filesystem on the same mount point */
err = -EBUSY;
- if (nd->mnt->mnt_sb == newmnt->mnt_sb &&
- nd->mnt->mnt_root == nd->dentry)
+ if (nd->path.mnt->mnt_sb == newmnt->mnt_sb &&
+ nd->path.mnt->mnt_root == nd->path.dentry)
goto unlock;
err = -EINVAL;
@@ -1697,12 +1702,14 @@
if (fs) {
atomic_inc(&fs->count);
task_unlock(p);
- if (fs->root == old_nd->dentry
- && fs->rootmnt == old_nd->mnt)
- set_fs_root(fs, new_nd->mnt, new_nd->dentry);
- if (fs->pwd == old_nd->dentry
- && fs->pwdmnt == old_nd->mnt)
- set_fs_pwd(fs, new_nd->mnt, new_nd->dentry);
+ if (fs->root == old_nd->path.dentry
+ && fs->rootmnt == old_nd->path.mnt)
+ set_fs_root(fs, new_nd->path.mnt,
+ new_nd->path.dentry);
+ if (fs->pwd == old_nd->path.dentry
+ && fs->pwdmnt == old_nd->path.mnt)
+ set_fs_pwd(fs, new_nd->path.mnt,
+ new_nd->path.dentry);
put_fs_struct(fs);
} else
task_unlock(p);
@@ -1752,7 +1759,7 @@
if (error)
goto out0;
error = -EINVAL;
- if (!check_mnt(new_nd.mnt))
+ if (!check_mnt(new_nd.path.mnt))
goto out1;
error = __user_walk(put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old_nd);
@@ -1766,55 +1773,59 @@
}
read_lock(¤t->fs->lock);
- user_nd.mnt = mntget(current->fs->rootmnt);
- user_nd.dentry = dget(current->fs->root);
+ user_nd.path.mnt = mntget(current->fs->rootmnt);
+ user_nd.path.dentry = dget(current->fs->root);
read_unlock(¤t->fs->lock);
down_write(&namespace_sem);
- mutex_lock(&old_nd.dentry->d_inode->i_mutex);
+ mutex_lock(&old_nd.path.dentry->d_inode->i_mutex);
error = -EINVAL;
- if (IS_MNT_SHARED(old_nd.mnt) ||
- IS_MNT_SHARED(new_nd.mnt->mnt_parent) ||
- IS_MNT_SHARED(user_nd.mnt->mnt_parent))
+ if (IS_MNT_SHARED(old_nd.path.mnt) ||
+ IS_MNT_SHARED(new_nd.path.mnt->mnt_parent) ||
+ IS_MNT_SHARED(user_nd.path.mnt->mnt_parent))
goto out2;
- if (!check_mnt(user_nd.mnt))
+ if (!check_mnt(user_nd.path.mnt))
goto out2;
error = -ENOENT;
- if (IS_DEADDIR(new_nd.dentry->d_inode))
+ if (IS_DEADDIR(new_nd.path.dentry->d_inode))
goto out2;
- if (d_unhashed(new_nd.dentry) && !IS_ROOT(new_nd.dentry))
+ if (d_unhashed(new_nd.path.dentry) && !IS_ROOT(new_nd.path.dentry))
goto out2;
- if (d_unhashed(old_nd.dentry) && !IS_ROOT(old_nd.dentry))
+ if (d_unhashed(old_nd.path.dentry) && !IS_ROOT(old_nd.path.dentry))
goto out2;
error = -EBUSY;
- if (new_nd.mnt == user_nd.mnt || old_nd.mnt == user_nd.mnt)
+ if (new_nd.path.mnt == user_nd.path.mnt ||
+ old_nd.path.mnt == user_nd.path.mnt)
goto out2; /* loop, on the same file system */
error = -EINVAL;
- if (user_nd.mnt->mnt_root != user_nd.dentry)
+ if (user_nd.path.mnt->mnt_root != user_nd.path.dentry)
goto out2; /* not a mountpoint */
- if (user_nd.mnt->mnt_parent == user_nd.mnt)
+ if (user_nd.path.mnt->mnt_parent == user_nd.path.mnt)
goto out2; /* not attached */
- if (new_nd.mnt->mnt_root != new_nd.dentry)
+ if (new_nd.path.mnt->mnt_root != new_nd.path.dentry)
goto out2; /* not a mountpoint */
- if (new_nd.mnt->mnt_parent == new_nd.mnt)
+ if (new_nd.path.mnt->mnt_parent == new_nd.path.mnt)
goto out2; /* not attached */
- tmp = old_nd.mnt; /* make sure we can reach put_old from new_root */
+ /* make sure we can reach put_old from new_root */
+ tmp = old_nd.path.mnt;
spin_lock(&vfsmount_lock);
- if (tmp != new_nd.mnt) {
+ if (tmp != new_nd.path.mnt) {
for (;;) {
if (tmp->mnt_parent == tmp)
goto out3; /* already mounted on put_old */
- if (tmp->mnt_parent == new_nd.mnt)
+ if (tmp->mnt_parent == new_nd.path.mnt)
break;
tmp = tmp->mnt_parent;
}
- if (!is_subdir(tmp->mnt_mountpoint, new_nd.dentry))
+ if (!is_subdir(tmp->mnt_mountpoint, new_nd.path.dentry))
goto out3;
- } else if (!is_subdir(old_nd.dentry, new_nd.dentry))
+ } else if (!is_subdir(old_nd.path.dentry, new_nd.path.dentry))
goto out3;
- detach_mnt(new_nd.mnt, &parent_nd);
- detach_mnt(user_nd.mnt, &root_parent);
- attach_mnt(user_nd.mnt, &old_nd); /* mount old root on put_old */
- attach_mnt(new_nd.mnt, &root_parent); /* mount new_root on / */
+ detach_mnt(new_nd.path.mnt, &parent_nd);
+ detach_mnt(user_nd.path.mnt, &root_parent);
+ /* mount old root on put_old */
+ attach_mnt(user_nd.path.mnt, &old_nd);
+ /* mount new_root on / */
+ attach_mnt(new_nd.path.mnt, &root_parent);
touch_mnt_namespace(current->nsproxy->mnt_ns);
spin_unlock(&vfsmount_lock);
chroot_fs_refs(&user_nd, &new_nd);
@@ -1823,7 +1834,7 @@
path_release(&root_parent);
path_release(&parent_nd);
out2:
- mutex_unlock(&old_nd.dentry->d_inode->i_mutex);
+ mutex_unlock(&old_nd.path.dentry->d_inode->i_mutex);
up_write(&namespace_sem);
path_release(&user_nd);
path_release(&old_nd);