Re: [PATCH] xfs: Start using pquotaino from the superblock.

Chandra Seetharaman
2013-07-12T20:32:39Z

On Fri, 2013-07-12 at 13:30 -0500, Ben Myers wrote:
> Hey Chandra,
>
<snip>

> > @@ -591,6 +599,19 @@ xfs_sb_quota_from_disk(struct xfs_sb *sbp)
> > sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
> > XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
> > sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
> > +
> > + if ((sbp->sb_qflags & XFS_PQUOTA_ACCT) &&
> > + (sbp->sb_gquotino != NULLFSINO)) {
>
> If project quota accounting bit is set in the super block
> and
> the group quot ino is not nullfsino..
>
> That's weird. I would have expected to be able to assume that sb_gquotino is
> not NULLFSINO if project quota accounting is on. Why was the check necessary?

Thinking now, I should not have added the second part.
(sbp->sb_qflags & XFS_PQUOTA_ACCT) should be sufficient.

>
> > + /*
> > + * On disk superblock only has sb_gquotino, and incore
> > + * superblock has both sb_gquotino and sb_pquotino.
> > + * But, only one of them is supported at any point of time.
> > + * So, if PQUOTA is set in disk superblock, copy over
> > + * sb_gquotino to sb_pquotino.
> > + */
> > + sbp->sb_pquotino = sbp->sb_gquotino;
> > + sbp->sb_gquotino = NULLFSINO;
> > + }
> > }
> >
> > void
> >
<snip>

> > diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> > index d320794..1e2361d 100644
> > --- a/fs/xfs/xfs_qm.c
> > +++ b/fs/xfs/xfs_qm.c
> > @@ -834,6 +834,36 @@ xfs_qm_qino_alloc(
> > int error;
> > int committed;
> >
> > + *ip = NULL;
> > + /*
> > + * With superblock that doesn't have separate pquotino, we
> > + * share an inode between gquota and pquota. If the on-disk
> > + * superblock has GQUOTA and the filesystem is now mounted
> > + * with PQUOTA, just use sb_gquotino for sb_pquotino and
> > + * vice-versa.
> > + */
> > + if (!xfs_sb_version_has_pquotino(&mp->m_sb) &&
> > + (flags & (XFS_QMOPT_PQUOTA|XFS_QMOPT_GQUOTA))) {
> > + xfs_ino_t ino = NULLFSINO;
> > +
> > + if ((flags & XFS_QMOPT_PQUOTA) &&
> > + (mp->m_sb.sb_gquotino != NULLFSINO)) {
> > + ino = mp->m_sb.sb_gquotino;
> > + ASSERT(mp->m_sb.sb_pquotino == NULLFSINO);
> > + } else if ((flags & XFS_QMOPT_GQUOTA) &&
> > + (mp->m_sb.sb_pquotino != NULLFSINO)) {
> > + ino = mp->m_sb.sb_pquotino;
> > + ASSERT(mp->m_sb.sb_gquotino == NULLFSINO);
> > + }
> > + if (ino != NULLFSINO) {
> > + error = xfs_iget(mp, NULL, ino, 0, 0, ip);
> > + if (error)
> > + return error;
> > + mp->m_sb.sb_gquotino = NULLFSINO;
> > + mp->m_sb.sb_pquotino = NULLFSINO;
> > + }
> > + }
>
> Looks like this is a new addition. I'm not completely clear on why you
> needed to add it. Maybe if the user had switched from using project
> quotas to group quotas there would be an old inode left out there from
> the project quotas? Is that why you added this? If so, wouldn't you

Yes. that is correct.
> want to truncate the old contents away before using it?

Yikes, now I realize it is needed. Was just maintaining the earlier
behavior (reuse the inode and nothing more), and did not realize
truncate was missing.

>
> > +
> > tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QINOCREATE);
> > if ((error = xfs_trans_reserve(tp,
> > XFS_QM_QINOCREATE_SPACE_RES(mp),

<snip>

> > diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
> > index e4f8b2d..8f4b8bc 100644
> > --- a/fs/xfs/xfs_qm_syscalls.c
> > +++ b/fs/xfs/xfs_qm_syscalls.c
> > @@ -296,8 +296,10 @@ xfs_qm_scall_trunc_qfiles(
> >
> > if (flags & XFS_DQ_USER)
> > error = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_uquotino);
> > - if (flags & (XFS_DQ_GROUP|XFS_DQ_PROJ))
> > + if (flags & XFS_DQ_GROUP)
> > error2 = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_gquotino);
> > + if (flags & XFS_DQ_PROJ)
> > + error2 = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_pquotino);
> >
> > return error ? error : error2;
> > }
> > @@ -413,8 +415,10 @@ xfs_qm_scall_getqstat(
> > struct xfs_quotainfo *q = mp->m_quotainfo;
> > struct xfs_inode *uip = NULL;
> > struct xfs_inode *gip = NULL;
> > + struct xfs_inode *pip = NULL;
> > bool tempuqip = false;
> > bool tempgqip = false;
> > + bool temppqip = false;
> >
> > memset(out, 0, sizeof(fs_quota_stat_t));
> >
> > @@ -424,6 +428,12 @@ xfs_qm_scall_getqstat(
> > out->qs_gquota.qfs_ino = NULLFSINO;
> > return (0);
> > }
> > +
> > + /* Q_XGETQSTAT doesn't have room for both group and project quotas */
> > + if ((mp->m_qflags & (XFS_PQUOTA_ACCT | XFS_GQUOTA_ACCT)) ==
> > + (XFS_PQUOTA_ACCT | XFS_GQUOTA_ACCT))
> > + return -EINVAL;
> > +
>
> Lets keep the rest of the crew in the loop with what we do on the
> quotactls.
>
> On our call, I found myself in agreement that the idea of returning
> -EINVAL in the old interface when user, group, and project quotas are
> turned on simultaneously would be ok. But today I'm not so sure.
> Classic bpm waffling... ;)

:)
>
> The quota rpm is separate from xfsprogs and could be much older; I think
> that there are those who will consider returning EINVAL here to be an
> API breakage.

>
> Maybe there are other options?
> - A sysctl to control which quota you get through the old group
> interface, when all three are turned on.

this would be changing the existing API, wouldn't it ?

> - Only report user and qroup quotas through the old interface, even when
> all three are turned on.
>
> Probably the old interface should still work in some fashion with a
> newer filesystem, but there don't seem to be many wonderful solutions.
>
> Anyway, I'd like to have Dave's reviewed-by and Jan's ack at a minimum
> before pulling in these -EINVAL bits. If this really is ok, lets have
> everybodys sig to make it official.

I understand.
>
> Thanks,
> Ben