Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount

From	Vivek Goyal <vgoyal@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount
Date	2017-02-15 21:40 +0100
Message-ID	<tbewO-4G5-9@gated-at.bofh.it> (permalink)
References	<t7e2l-4XW-5@gated-at.bofh.it> <t7e2l-4XW-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Sat, Feb 04, 2017 at 11:19:32AM -0800, James Bottomley wrote:

[..]
> +static struct dentry *shiftfs_lookup(struct inode *dir, struct dentry *dentry,
> +				     unsigned int flags)
> +{
> +	struct dentry *real = dir->i_private, *new;
> +	struct inode *reali = real->d_inode, *newi;
> +	const struct cred *oldcred, *newcred;
> +
> +	inode_lock(reali);
> +	oldcred = shiftfs_new_creds(&newcred, dentry->d_sb);
> +	new = lookup_one_len(dentry->d_name.name, real, dentry->d_name.len);
> +	shiftfs_old_creds(oldcred, &newcred);
> +	inode_unlock(reali);
> +
> +	if (IS_ERR(new))
> +		return new;
> +
> +	dentry->d_fsdata = new;
> +
> +	if (!new->d_inode)
> +		return NULL;
> +
> +	newi = shiftfs_new_inode(dentry->d_sb, new->d_inode->i_mode, new);
> +	if (!newi) {
> +		dput(new);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	d_splice_alias(newi, dentry);

Hi James,

Should it be "return d_splice_alias()" so that if we find an alias it is
returned back to caller and passed in dentry can be freed. Though I don't
know in what cases alias can be found. And if alias is found how do we
make sure alias_dentry->d_fsdata is pointing to new (real dentry).

> +
> +	return NULL;
> +}

Vivek

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount Vivek Goyal <vgoyal@redhat.com> - 2017-02-15 21:40 +0100
  Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-02-16 17:00 +0100
    Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount Al Viro <viro@ZenIV.linux.org.uk> - 2017-02-17 04:00 +0100
      Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-02-17 18:40 +0100
        Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount Vivek Goyal <vgoyal@redhat.com> - 2017-02-17 21:50 +0100
          Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-02-19 04:30 +0100
            Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount Vivek Goyal <vgoyal@redhat.com> - 2017-02-20 20:30 +0100
              Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-02-21 01:40 +0100

csiph-web