On Thu, Jan 22, 2015 at 06:28:51PM +0300, Konstantin Khlebnikov wrote:
> On 09.12.2014 08:22, Li Xi wrote:
> >+static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
> >+{
> >+ struct inode *inode = file_inode(filp);
> >+ struct super_block *sb = inode->i_sb;
> >+ struct ext4_inode_info *ei = EXT4_I(inode);
> >+ int err;
> >+ handle_t *handle;
> >+ kprojid_t kprojid;
> >+ struct ext4_iloc iloc;
> >+ struct ext4_inode *raw_inode;
> >+
> >+ struct dquot *transfer_to[EXT4_MAXQUOTAS] = { };
> >+
> >+ /* Make sure caller can change project. */
> >+ if (!capable(CAP_SYS_ADMIN))
> >+ return -EACCES;
> >+
> >+ if (projid != EXT4_DEF_PROJID
> >+ && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
> >+ EXT4_FEATURE_RO_COMPAT_PROJECT))
> >+ return -EOPNOTSUPP;
> >+
> >+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
> >+ EXT4_FEATURE_RO_COMPAT_PROJECT)) {
> >+ BUG_ON(__kprojid_val(EXT4_I(inode)->i_projid)
> >+ != EXT4_DEF_PROJID);
> >+ if (projid != EXT4_DEF_PROJID)
> >+ return -EOPNOTSUPP;
> >+ else
> >+ return 0;
> >+ }
> >+
> >+ kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
>
> Maybe current_user_ns()?
> This code should be user-namespace aware from the beginning.
No, the code is correct. Project quotas have nothing to do with
UIDs and so should never have been included in the uid/gid
namespace mapping infrastructure in the first place.
Point in case: directory subtree quotas can be used as a resource
controller for limiting space usage within separate containers that
share the same underlying (large) filesystem via mount namespaces.
Cheers,
Dave.
PS: can you please trim your reply to just the sections of the
patch you are commenting to? Finding replies like this in a large
patch is like searching for a needle in a haystack...
--
Dave Chinner
david@xxxxxxxxxxxxx
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