From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis Henriques Subject: Re: [PATCH v2 2/2] ceph: quota: fix quota subdir mounts Date: Mon, 18 Mar 2019 10:55:45 +0000 Message-ID: <87lg1czc26.fsf@suse.com> References: <20190312142019.30936-1-lhenriques@suse.com> <20190312142019.30936-3-lhenriques@suse.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: (Zheng Yan's message of "Mon, 18 Mar 2019 17:12:39 +0800") Sender: linux-kernel-owner@vger.kernel.org To: "Yan, Zheng" Cc: Gregory Farnum , "Yan, Zheng" , Sage Weil , Ilya Dryomov , ceph-devel , Linux Kernel Mailing List , Hendrik Peyerl List-Id: ceph-devel.vger.kernel.org "Yan, Zheng" writes: > On Mon, Mar 18, 2019 at 5:06 PM Gregory Farnum wrote: >> >> On Mon, Mar 18, 2019 at 2:32 PM Yan, Zheng wrote: >> > After reading the code carefully. I feel a little uncomfortable with >> > the "lookup_ino" in get_quota_realm. how about populating directories >> > above the 'mount subdir' during mounting (similar to cifs_get_root ). Wouldn't it be a problem if the directory layout (or, in this case, the snaprealm layout) change during the mount lifetime? In that case we would need to do this lookup anyway. >> >> Isn't that going to be a problem for any clients which have >>restricted filesystem access permissions? They may not be able to see >>all the directories above their mount point. -Greg > > using lookup_ino to get inode above the "mount subdir" has the same problem > In this case I believe we get an -EPERM from the MDS. And then the client simply falls back to the 'default' behaviour, which is to allow the user to create/write to files as if there were no quotas set. Cheers, -- Luis