From: Dave Chinner Subject: Re: [v8 4/5] ext4: adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support Date: Fri, 23 Jan 2015 12:53:07 +1100 Message-ID: <20150123015307.GD24722@dastard> References: <1418102548-5469-1-git-send-email-lixi@ddn.com> <1418102548-5469-5-git-send-email-lixi@ddn.com> <54C11733.7080801@yandex-team.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Li Xi , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tytso-3s7WtUTddSA@public.gmane.org, adilger-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org, jack-AlSwsSmVLrQ@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, dmonakhov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org To: Konstantin Khlebnikov Return-path: Content-Disposition: inline In-Reply-To: <54C11733.7080801-XoJtRXgx1JseBXzfvpsJ4g@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org 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-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org