On Wed, May 13, 2020 at 12:39:00PM -0500, Eric Sandeen wrote:
> XFS project quota treats project hierarchies as "mini filesysems" and
> so rather than -EDQUOT, the intent is to return -ENOSPC when a quota
> reservation fails, but this behavior is not consistent.
>
> The only place we make a decision between -EDQUOT and -ENOSPC
> returns based on quota type is in xfs_trans_dqresv().
>
> This behavior is currently controlled by whether or not the
> XFS_QMOPT_ENOSPC flag gets passed into the quota reservation. However,
> its use is not consistent; paths such as xfs_create() and xfs_symlink()
> don't set the flag, so a reservation failure will return -EDQUOT for
> project quota reservation failures rather than -ENOSPC for these sorts
> of operations, even for project quota:
>
> # mkdir mnt/project
> # xfs_quota -x -c "project -s -p mnt/project 42" mnt
> # xfs_quota -x -c 'limit -p isoft=2 ihard=3 42' mnt
> # touch mnt/project/file{1,2,3}
> touch: cannot touch ‘mnt/project/file3’: Disk quota exceeded
>
> We can make this consistent by not requiring the flag to be set at the
> top of the callchain; instead we can simply test whether we are
> reserving a project quota with XFS_QM_ISPDQ in xfs_trans_dqresv and if
> so, return -ENOSPC for that failure. This removes the need for the
> XFS_QMOPT_ENOSPC altogether and simplifies the code a fair bit.
>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> ---
Thanks for the update.
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
>
> V2: Change title and changelog to clearly reflect the bug and behavior
> change, which wasn't really identified as a bug and behavior change until
> Brian carefully reviewed V1. :)
>
> No patch changes.
>
> diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h
> index b2113b17e53c..56d9dd787e7b 100644
> --- a/fs/xfs/libxfs/xfs_quota_defs.h
> +++ b/fs/xfs/libxfs/xfs_quota_defs.h
> @@ -100,7 +100,6 @@ typedef uint16_t xfs_qwarncnt_t;
> #define XFS_QMOPT_FORCE_RES 0x0000010 /* ignore quota limits */
> #define XFS_QMOPT_SBVERSION 0x0000040 /* change superblock version num */
> #define XFS_QMOPT_GQUOTA 0x0002000 /* group dquot requested */
> -#define XFS_QMOPT_ENOSPC 0x0004000 /* enospc instead of edquot (prj) */
>
> /*
> * flags to xfs_trans_mod_dquot to indicate which field needs to be
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index c225691fad15..591779aa2fd0 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -1808,7 +1808,7 @@ xfs_qm_vop_chown_reserve(
> {
> struct xfs_mount *mp = ip->i_mount;
> uint64_t delblks;
> - unsigned int blkflags, prjflags = 0;
> + unsigned int blkflags;
> struct xfs_dquot *udq_unres = NULL;
> struct xfs_dquot *gdq_unres = NULL;
> struct xfs_dquot *pdq_unres = NULL;
> @@ -1849,7 +1849,6 @@ xfs_qm_vop_chown_reserve(
>
> if (XFS_IS_PQUOTA_ON(ip->i_mount) && pdqp &&
> ip->i_d.di_projid != be32_to_cpu(pdqp->q_core.d_id)) {
> - prjflags = XFS_QMOPT_ENOSPC;
> pdq_delblks = pdqp;
> if (delblks) {
> ASSERT(ip->i_pdquot);
> @@ -1859,8 +1858,7 @@ xfs_qm_vop_chown_reserve(
>
> error = xfs_trans_reserve_quota_bydquots(tp, ip->i_mount,
> udq_delblks, gdq_delblks, pdq_delblks,
> - ip->i_d.di_nblocks, 1,
> - flags | blkflags | prjflags);
> + ip->i_d.di_nblocks, 1, flags | blkflags);
> if (error)
> return error;
>
> @@ -1878,8 +1876,7 @@ xfs_qm_vop_chown_reserve(
> ASSERT(udq_unres || gdq_unres || pdq_unres);
> error = xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
> udq_delblks, gdq_delblks, pdq_delblks,
> - (xfs_qcnt_t)delblks, 0,
> - flags | blkflags | prjflags);
> + (xfs_qcnt_t)delblks, 0, flags | blkflags);
> if (error)
> return error;
> xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
> diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
> index 2c3557a80e69..2c07897a3c37 100644
> --- a/fs/xfs/xfs_trans_dquot.c
> +++ b/fs/xfs/xfs_trans_dquot.c
> @@ -711,7 +711,7 @@ xfs_trans_dqresv(
>
> error_return:
> xfs_dqunlock(dqp);
> - if (flags & XFS_QMOPT_ENOSPC)
> + if (XFS_QM_ISPDQ(dqp))
> return -ENOSPC;
> return -EDQUOT;
> }
> @@ -751,15 +751,13 @@ xfs_trans_reserve_quota_bydquots(
> ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
>
> if (udqp) {
> - error = xfs_trans_dqresv(tp, mp, udqp, nblks, ninos,
> - (flags & ~XFS_QMOPT_ENOSPC));
> + error = xfs_trans_dqresv(tp, mp, udqp, nblks, ninos, flags);
> if (error)
> return error;
> }
>
> if (gdqp) {
> - error = xfs_trans_dqresv(tp, mp, gdqp, nblks, ninos,
> - (flags & ~XFS_QMOPT_ENOSPC));
> + error = xfs_trans_dqresv(tp, mp, gdqp, nblks, ninos, flags);
> if (error)
> goto unwind_usr;
> }
> @@ -804,16 +802,12 @@ xfs_trans_reserve_quota_nblks(
>
> if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
> return 0;
> - if (XFS_IS_PQUOTA_ON(mp))
> - flags |= XFS_QMOPT_ENOSPC;
>
> ASSERT(!xfs_is_quota_inode(&mp->m_sb, ip->i_ino));
>
> ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
> - ASSERT((flags & ~(XFS_QMOPT_FORCE_RES | XFS_QMOPT_ENOSPC)) ==
> - XFS_TRANS_DQ_RES_RTBLKS ||
> - (flags & ~(XFS_QMOPT_FORCE_RES | XFS_QMOPT_ENOSPC)) ==
> - XFS_TRANS_DQ_RES_BLKS);
> + ASSERT((flags & ~(XFS_QMOPT_FORCE_RES)) == XFS_TRANS_DQ_RES_RTBLKS ||
> + (flags & ~(XFS_QMOPT_FORCE_RES)) == XFS_TRANS_DQ_RES_BLKS);
>
> /*
> * Reserve nblks against these dquots, with trans as the mediator.
>
>
>
