xfs: Do not allow norecovery mount with quotacheck

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_state_change(), factoring the
quota state changes out of xfs_qm_newmount() to reduce cluttering
within it.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

diff --git a/fs/xfs/xfs_qm_bhv.c b/fs/xfs/xfs_qm_bhv.c
index 37f1230e75846af05ae2282a90cfada3100cd5d1..245d754f382a721df0a868d9a59facc59da703e8 100644 (file)
--- 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_state_change(
+       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_state_change(mp, uquotaondisk,
+                           gquotaondisk, pquotaondisk)) {
+
+               if (xfs_has_metadir(mp))
+                       xfs_warn(mp,
+               "metadir enabled, please mount without any quota mount options");
+               else
+                       xfs_warn(mp, "please mount with%s%s%s%s.",
+                               (!quotaondisk ? "out quota" : ""),
+                               (uquotaondisk ? " usrquota" : ""),
+                               (gquotaondisk ? " grpquota" : ""),
+                               (pquotaondisk ? " prjquota" : ""));
                return -EPERM;
        }