On Fri, Jan 31, 2025 at 08:18:06AM -0800, Darrick J. Wong wrote:
> On Fri, Jan 31, 2025 at 11:02:54AM +0100, cem@xxxxxxxxxx wrote:
> > From: Carlos Maiolino <cem@xxxxxxxxxx>
> >
> > Mounting a filesystem that requires quota state changing will generate a
> > transaction.
> >
> > We already check for a read-only device; we should do that for
> > norecovery too.
> >
> > A quotacheck on a norecovery mount, and with the right log size, will cause
> > the mount process to hang on:
> >
> > [<0>] xlog_grant_head_wait+0x5d/0x2a0 [xfs]
> > [<0>] xlog_grant_head_check+0x112/0x180 [xfs]
> > [<0>] xfs_log_reserve+0xe3/0x260 [xfs]
> > [<0>] xfs_trans_reserve+0x179/0x250 [xfs]
> > [<0>] xfs_trans_alloc+0x101/0x260 [xfs]
> > [<0>] xfs_sync_sb+0x3f/0x80 [xfs]
> > [<0>] xfs_qm_mount_quotas+0xe3/0x2f0 [xfs]
> > [<0>] xfs_mountfs+0x7ad/0xc20 [xfs]
> > [<0>] xfs_fs_fill_super+0x762/0xa50 [xfs]
> > [<0>] get_tree_bdev_flags+0x131/0x1d0
> > [<0>] vfs_get_tree+0x26/0xd0
> > [<0>] vfs_cmd_create+0x59/0xe0
> > [<0>] __do_sys_fsconfig+0x4e3/0x6b0
> > [<0>] do_syscall_64+0x82/0x160
> > [<0>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> >
> > This is caused by a transaction running with bogus initialized head/tail
> >
> > I initially hit this while running generic/050, with random log
> > sizes, but I managed to reproduce it reliably here with the steps
> > below:
> >
> > mkfs.xfs -f -lsize=1025M -f -b size=4096 -m crc=1,reflink=1,rmapbt=1, -i
> > sparse=1 /dev/vdb2 > /dev/null
> > mount -o usrquota,grpquota,prjquota /dev/vdb2 /mnt
> > xfs_io -x -c 'shutdown -f' /mnt
> > umount /mnt
> > mount -o ro,norecovery,usrquota,grpquota,prjquota /dev/vdb2 /mnt
> >
> > Last mount hangs up
> >
> > As we add yet another validation if quota state is changing, this also
> > add a new helper named xfs_qm_validate(), factoring the quota state
> > changes out of xfs_qm_newmount() to reduce cluttering within it.
> >
> > As per Darrick suggestion, add a new, different warning message if
> > metadir is enabled.
> >
> > Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> > Signed-off-by: Carlos Maiolino <cem@xxxxxxxxxx>
> > ---
> >
> > Changelog V1->V2:
> > - Issue a different warn message in case metadir is enabled
> > - Factour out quota state validator code to a new helper
> > - Change patch subject to reduce length
> >
> >
> > fs/xfs/xfs_qm_bhv.c | 55 ++++++++++++++++++++++++++++++++-------------
> > 1 file changed, 39 insertions(+), 16 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_qm_bhv.c b/fs/xfs/xfs_qm_bhv.c
> > index 37f1230e7584..a6a7870401c3 100644
> > --- a/fs/xfs/xfs_qm_bhv.c
> > +++ b/fs/xfs/xfs_qm_bhv.c
> > @@ -78,6 +78,28 @@ xfs_qm_statvfs(
> > }
> > }
> >
> > +STATIC int
> > +xfs_qm_validate(
>
> This validates ... what exactly?
>
> Oh, it validates that we can actually make the state change.
>
> xfs_qm_validate_state_change(), perhaps ?
Yeah, I thought the name would be too big, but indeed looks decent
>
> > + xfs_mount_t *mp,
>
> Please don't introduce more typedef usage.
Ditto, my bad, will fix.
>
> struct xfs_mount *mp,
>
> > + uint uqd,
> > + uint gqd,
> > + uint pqd)
> > +{
> > + int state;
> > +
> > + /* Is quota state changing? */
> > + state = ((uqd && !XFS_IS_UQUOTA_ON(mp)) ||
> > + (!uqd && XFS_IS_UQUOTA_ON(mp)) ||
> > + (gqd && !XFS_IS_GQUOTA_ON(mp)) ||
> > + (!gqd && XFS_IS_GQUOTA_ON(mp)) ||
> > + (pqd && !XFS_IS_PQUOTA_ON(mp)) ||
> > + (!pqd && XFS_IS_PQUOTA_ON(mp)));
> > +
> > + return state &&
> > + (xfs_dev_is_read_only(mp, "changing quota state") ||
> > + xfs_has_norecovery(mp));
> > +}
> > +
> > int
> > xfs_qm_newmount(
> > xfs_mount_t *mp,
> > @@ -97,24 +119,25 @@ xfs_qm_newmount(
> > }
> >
> > /*
> > - * If the device itself is read-only, we can't allow
> > - * the user to change the state of quota on the mount -
> > - * this would generate a transaction on the ro device,
> > - * which would lead to an I/O error and shutdown
> > + * If the device itself is read-only and/or in norecovery
> > + * mode, we can't allow the user to change the state of
> > + * quota on the mount - this would generate a transaction
> > + * on the ro device, which would lead to an I/O error and
> > + * shutdown.
> > */
> >
> > - if (((uquotaondisk && !XFS_IS_UQUOTA_ON(mp)) ||
> > - (!uquotaondisk && XFS_IS_UQUOTA_ON(mp)) ||
> > - (gquotaondisk && !XFS_IS_GQUOTA_ON(mp)) ||
> > - (!gquotaondisk && XFS_IS_GQUOTA_ON(mp)) ||
> > - (pquotaondisk && !XFS_IS_PQUOTA_ON(mp)) ||
> > - (!pquotaondisk && XFS_IS_PQUOTA_ON(mp))) &&
> > - xfs_dev_is_read_only(mp, "changing quota state")) {
> > - xfs_warn(mp, "please mount with%s%s%s%s.",
> > - (!quotaondisk ? "out quota" : ""),
> > - (uquotaondisk ? " usrquota" : ""),
> > - (gquotaondisk ? " grpquota" : ""),
> > - (pquotaondisk ? " prjquota" : ""));
> > + if (xfs_qm_validate(mp, uquotaondisk,
> > + gquotaondisk, pquotaondisk)) {
> > +
> > + if (xfs_has_metadir(mp))
> > + xfs_warn(mp,
> > + "metadir enabled, please mount withouth quotas");
>
> "metadir enabled, please mount without any quota mount options"
Thanks for the review, V3 soon.
>
> --D
>
> > + else
> > + xfs_warn(mp, "please mount with%s%s%s%s.",
> > + (!quotaondisk ? "out quota" : ""),
> > + (uquotaondisk ? " usrquota" : ""),
> > + (gquotaondisk ? " grpquota" : ""),
> > + (pquotaondisk ? " prjquota" : ""));
> > return -EPERM;
> > }
> >
> > --
> > 2.48.1
> >
> >
>
