| Message ID | 20220602003126.2903779-4-david@fromorbit.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/8] xfstests: Add Log Attribute Replay test | expand |
On Thu, Jun 02, 2022 at 10:31:21AM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > LVM/DM has conniptions when you try to use snapshots on a device > that has DAX capability. It first sets up the underlying device as a > DAX capable mapping (type 3 or DM_TYPE_DAX_BIO_BASED) but because > snapshots require COW and shared mappings, it isn't supported on DAX > capable devices. Hence creating the snapshot device fails because it > requires a type 1 (DM_TYPE_BIO_BASED) device and DM can't change > types on a loaded mapping. > > Hence we get this obscure error message in the log: > > device-mapper: ioctl: can't change device type (old=3 vs new=1) after initial table load. > > and these obscure, unhelpful error messages from the LVM command > outputs: > > device-mapper: reload ioctl on (251:0) failed: Invalid argument > Failed to suspend logical volume vg_081/base_081. > Device vg_081-base_081-real (251:1) is used by another device. > Failed to revert logical volume vg_081/base_081. > Aborting. Manual intervention required. > Failed to create snapshot > > How to turn off DAX capability is not documented in dmsetup or LVM > man pages, nor is dax mentioned anywhere in > Documentation/admin/device-mapper/ so I have no idea how to tell > LVM/DM "don't try to enable DAX support!". > > As such, if the uderlying block device is dax capable, skip this > test. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> Seems reasonable to me, who also sees weird problems on the dax vms... Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > common/rc | 39 +++++++++++++++++++++++++++------------ > 1 file changed, 27 insertions(+), 12 deletions(-) > > diff --git a/common/rc b/common/rc > index 2f31ca46..c334cfbf 100644 > --- a/common/rc > +++ b/common/rc > @@ -2116,21 +2116,33 @@ _require_sane_bdev_flush() > # Decide if the scratch filesystem is likely to be mounted in fsdax mode. > # It goes 3 ways based on mount options:: > # 1. "dax" or "dax=always" means always test using DAX > -# 2. "dax=never" means we'll never use DAX > +# 2. "dax=never" means we'll never use DAX. > # 3. "dax=inode" or nothing means "use scratch dev capability" to > # determine whether DAX is going to be used. > # > -# Returns 0 if DAX will be used, 1 if DAX is not going to be used. > +# Case 2 and 3 basically mean the same thing for the purpose of > +# _require_dm_target(). If the fs is not forcing the use of DAX, then DAX > +# can only be enabled if the underlying block device supports it. > +# > +# Returns 0 if the filesytem will use DAX, 1 if it won't. > __scratch_uses_fsdax() > { > local ops=$(_normalize_mount_options "$MOUNT_OPTIONS") > > echo $ops | egrep -qw "dax(=always| |$)" && return 0 > - echo $ops | grep -qw "dax=never" && return 1 > + return 1 > +} > > +# Determine if the scratch device is DAX capable. Even if the fs is not > +# using DAX, we still can't use certain device mapper targets if the block > +# device is DAX capable. Hence the check needs to be separat from the FS > +# capability. > +__scratch_dev_has_dax() > +{ > local sysfs="/sys/block/$(_short_dev $SCRATCH_DEV)" > test -e "${sysfs}/dax" && return 0 > test "$(cat "${sysfs}/queue/dax" 2>/dev/null)" = "1" && return 0 > + > return 1 > } > > @@ -2147,15 +2159,18 @@ _require_dm_target() > _require_sane_bdev_flush $SCRATCH_DEV > _require_command "$DMSETUP_PROG" dmsetup > > - if __scratch_uses_fsdax; then > - case $target in > - stripe|linear|log-writes) > - ;; > - *) > - _notrun "Cannot run tests with DAX on $target devices." > - ;; > - esac > - fi > + case $target in > + stripe|linear|log-writes) > + ;; > + *) > + if __scratch_uses_fsdax; then > + _notrun "Cannot run tests with fsdax on $target devices." > + fi > + if __scratch_dev_has_dax; then > + _notrun "Cannot use $target devices on DAX capable block devices." > + fi > + ;; > + esac > > modprobe dm-$target >/dev/null 2>&1 > > -- > 2.35.1 >
diff --git a/common/rc b/common/rc index 2f31ca46..c334cfbf 100644 --- a/common/rc +++ b/common/rc @@ -2116,21 +2116,33 @@ _require_sane_bdev_flush() # Decide if the scratch filesystem is likely to be mounted in fsdax mode. # It goes 3 ways based on mount options:: # 1. "dax" or "dax=always" means always test using DAX -# 2. "dax=never" means we'll never use DAX +# 2. "dax=never" means we'll never use DAX. # 3. "dax=inode" or nothing means "use scratch dev capability" to # determine whether DAX is going to be used. # -# Returns 0 if DAX will be used, 1 if DAX is not going to be used. +# Case 2 and 3 basically mean the same thing for the purpose of +# _require_dm_target(). If the fs is not forcing the use of DAX, then DAX +# can only be enabled if the underlying block device supports it. +# +# Returns 0 if the filesytem will use DAX, 1 if it won't. __scratch_uses_fsdax() { local ops=$(_normalize_mount_options "$MOUNT_OPTIONS") echo $ops | egrep -qw "dax(=always| |$)" && return 0 - echo $ops | grep -qw "dax=never" && return 1 + return 1 +} +# Determine if the scratch device is DAX capable. Even if the fs is not +# using DAX, we still can't use certain device mapper targets if the block +# device is DAX capable. Hence the check needs to be separat from the FS +# capability. +__scratch_dev_has_dax() +{ local sysfs="/sys/block/$(_short_dev $SCRATCH_DEV)" test -e "${sysfs}/dax" && return 0 test "$(cat "${sysfs}/queue/dax" 2>/dev/null)" = "1" && return 0 + return 1 } @@ -2147,15 +2159,18 @@ _require_dm_target() _require_sane_bdev_flush $SCRATCH_DEV _require_command "$DMSETUP_PROG" dmsetup - if __scratch_uses_fsdax; then - case $target in - stripe|linear|log-writes) - ;; - *) - _notrun "Cannot run tests with DAX on $target devices." - ;; - esac - fi + case $target in + stripe|linear|log-writes) + ;; + *) + if __scratch_uses_fsdax; then + _notrun "Cannot run tests with fsdax on $target devices." + fi + if __scratch_dev_has_dax; then + _notrun "Cannot use $target devices on DAX capable block devices." + fi + ;; + esac modprobe dm-$target >/dev/null 2>&1