Move the check for the supported CNS value into nvme_scan_ns_list, and
limit the life time of the identify controller allocation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a helper to check if we can use Identify CNS values > 1, and refine
the Qemu quirk to not apply to reported versions larger than 1.1, as the
Qemu implementation had been fixed by then.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

nvme_alloc_ns_head() doesn't use the 'struct nvme_id_ns' parameter.
Remove it, and update caller accordingly.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Various nvme commands use a zeroes based number of dwords field. Create
a helper function to convert byte lengths to this format.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When the controller is reconnecting, the host fails I/O and admin
commands as the host cannot reach the controller. ns scanning may
revalidate namespaces during that period and it is wrong to remove
namespaces due to these failures as we may hang (see 205da243).

One command that may fail is nvme_identify_ns_descs. Since we return
success due to having ns identify descriptor list optional, we continue
to compare ns identifiers in nvme_revalidate_disk, obviously fail and
return -ENODEV to nvme_validate_ns, which will remove the namespace.

Exactly what we don't want to happen.

Fixes: 22802bf7 ("nvme: Namepace identification descriptor list is optional")
Tested-by: NAnton Eidelman <anton@lightbitslabs.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When jumping to the out_put_disk label, we will call put_disk(), which will
trigger a call to disk_release(), which calls blk_put_queue().

Later in the cleanup code, we do blk_cleanup_queue(), which will also call
blk_put_queue().

Putting the queue twice is incorrect, and will generate a KASAN splat.

Set the disk->queue pointer to NULL, before calling put_disk(), so that the
first call to blk_put_queue() will not free the queue.

The second call to blk_put_queue() uses another pointer to the same queue,
so this call will still free the queue.

Fixes: 85136c01 ("lightnvm: simplify geometry enumeration")
Signed-off-by: NNiklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

If the backing device require stable pages, we need to set it on the
stack mpath device as well. This applies to rdma/fc transports when
doing data integrity and tcp transport calculating digests.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On a 32-bit kernel, the upper bits of userspace addresses passed via
various ioctls are silently ignored by the nvme driver.

However on a 64-bit kernel running a compat task, these upper bits are
not ignored and are in fact required to be zero for the ioctls to work.

Unfortunately, this difference matters.  32-bit smartctl submits the
NVME_IOCTL_ADMIN_CMD ioctl with garbage in these upper bits because it
seems the pointer value it puts into the nvme_passthru_cmd structure is
sign extended.  This works fine on 32-bit kernels but fails on a 64-bit
one because (at least on my setup) the addresses smartctl uses are
consistently above 2G.  For example:

  # smartctl -x /dev/nvme0n1
  smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.5.11] (local build)
  Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

  Read NVMe Identify Controller failed: NVME_IOCTL_ADMIN_CMD: Bad address

Since changing 32-bit kernels to actually check all of the submitted
address bits now would break existing userspace, this patch fixes the
compat problem by explicitly zeroing the upper bits in the compat case.
This enables 32-bit smartctl to work on a 64-bit kernel.
Signed-off-by: NNick Bowler <nbowler@draconx.ca>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Lift the common namespace identifier reporting between the shared
namespace and new nshead cases into common code.  This also means
one less lock is held while doing I/O.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

There is no non __-prefixed version, so make the name a little more
readable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Move the handling of an error into the function from the caller, and
only do it for an actual error on the admin command itself, not the
command parsing, as that should be enough to deal with devices claiming
a bogus version compliance.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Calling nvme_sysfs_delete() when the controller is in the middle of
creation may cause several bugs. If the controller is in NEW state we
remove delete_controller file and don't delete the controller. The user
will not be able to use nvme disconnect command on that controller again,
although the controller may be active. Other bugs may happen if the
controller is in the middle of create_ctrl callback and
nvme_do_delete_ctrl() starts. For example, freeing I/O tagset at
nvme_do_delete_ctrl() before it was allocated at create_ctrl callback.

To fix all those races don't allow the user to delete the controller
before it was fully created.
Signed-off-by: NIsrael Rukshin <israelr@mellanox.com>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Put the ctrl reference count at nvme_uninit_ctrl as opposed to
nvme_init_ctrl which takes it. This decrease the reference count at the
core layer instead of decreasing it on each transport separately.
Also move the call of nvme_uninit_ctrl at PCI driver after calling to
nvme_release_prp_pools and nvme_dev_unmap, in order to put the reference
count after using the dev. This is safe because those functions use
nvme_dev which is freed only later at nvme_pci_free_ctrl.
Signed-off-by: NIsrael Rukshin <israelr@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

In case nvme_sysfs_delete() is called by the user before taking the ctrl
reference count, the ctrl may be freed during the creation and cause the
bug. Take the reference as soon as the controller is externally visible,
which is done by cdev_device_add() in nvme_init_ctrl(). Also take the
reference count at the core layer instead of taking it on each transport
separately.
Signed-off-by: NIsrael Rukshin <israelr@mellanox.com>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

The return code of nvme_delete_ctrl_sync is never used, so change it to
void.
Signed-off-by: NIsrael Rukshin <israelr@mellanox.com>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Improve code readability.
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NIsrael Rukshin <israelr@mellanox.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

ida instances allocate some internal memory in addition to the base
'struct ida'. Use ida_destroy() to release that memory at module_exit().
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Currently 32 bit application gets ENOTTY when it calls
compat_ioctl with NVME_IOCTL_SUBMIT_IO in 64 bit kernel.

The cause is that the results of sizeof(struct nvme_user_io),
which is used to define NVME_IOCTL_SUBMIT_IO,
are not same between 32 bit compiler and 64 bit compiler.

* 32 bit: the result of sizeof nvme_user_io is 44.
* 64 bit: the result of sizeof nvme_user_io is 48.

64 bit compiler seems to add 32 bit padding for multiple of 8 bytes.

This patch adds a compat_ioctl handler.
The handler replaces NVME_IOCTL_SUBMIT_IO32 with NVME_IOCTL_SUBMIT_IO
in case 32 bit application calls compat_ioctl for submit in 64 bit kernel.
Then, it calls nvme_ioctl as usual.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMasahiro Yamada (KIOXIA) <masahiro31.yamada@kioxia.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

The nvme multipath error handling defaults to controller reset if the
error is unknown. There are, however, no existing nvme status codes that
indicate a reset should be used, and resetting causes unnecessary
disruption to the rest of IO.

Change nvme's error handling to first check if failover should happen.
If not, let the normal error handling take over rather than reset the
controller.
Based-on-a-patch-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJohn Meneghini <johnm@netapp.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

After initialization, nvme_wait_ready checks for readiness every 100ms,
even though the drive may be ready far sooner than that. This delays
system boot by hundreds of milliseconds. Reduce the delay, checking for
readiness every millisecond instead.

Boot-time tests on an AWS c5.12xlarge:

Before:
[    0.546936] initcall nvme_init+0x0/0x5b returned 0 after 37 usecs
...
[    0.764178] nvme nvme0: 2/0/0 default/read/poll queues
[    0.768424]  nvme0n1: p1
[    0.774132] EXT4-fs (nvme0n1p1): mounted filesystem with ordered data mode. Opts: (null)
[    0.774146] VFS: Mounted root (ext4 filesystem) on device 259:1.
...
[    0.788141] Run /sbin/init as init process

After:
[    0.537088] initcall nvme_init+0x0/0x5b returned 0 after 37 usecs
...
[    0.543457] nvme nvme0: 2/0/0 default/read/poll queues
[    0.548473]  nvme0n1: p1
[    0.554339] EXT4-fs (nvme0n1p1): mounted filesystem with ordered data mode. Opts: (null)
[    0.554344] VFS: Mounted root (ext4 filesystem) on device 259:1.
...
[    0.567931] Run /sbin/init as init process
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Log the controller status to know more about issue if it
lies within kernel nvme subsytem or controller is unhealthy.
Signed-off-by: NRupesh Girase <rgirase@redhat.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulakrni@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

The function nvme_identify_ns_desc() has 3 levels of nesting which make
error message to exceeded > 80 char per line which is not aligned with
the kernel code standards and rest of the NVMe subsystem code.

Add a helper function to move the processing of the log when the
command is successful by reducing the nesting and keeping the
code < 80 char per line.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

We allow userspace to connect with a custom hostid which is useful for
certain use-cases. However there is is no way to tell what is the hostid
used to connect to a given controller.

Expose this so userspace can correlate controllers based on hostid.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

We allow userspace to connect with a custom hostnqn which is useful for
certain use-cases. However there is no way to tell what is the hostnqn
used to connect to a given controller.

Expose this so userspace can correlate controllers based on hostnqn.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

block/genhd provides set_capacity_revalidate_and_notify() for
sending RESIZE notifications via uevents. This notification is
newly added to NVME devices
Signed-off-by: NBalbir Singh <sblbir@amazon.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The return code of nvme_alloc_ns is never used, so change it
to void.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

gcc may detect a false positive on nvme using an unintialized variable
if setting features fails. Since this is not a fast path, explicitly
initialize this variable to suppress the warning.
Reported-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

nvme fw-activate operation will get bellow warning log,
fix it by update the parameter order

[  113.231513] nvme nvme0: Get FW SLOT INFO log error

Fixes: 0e98719b ("nvme: simplify the API for getting log pages")
Reported-by: NSujith Pandel <sujith_pandel@dell.com>
Reviewed-by: NDavid Milburn <dmilburn@redhat.com>
Signed-off-by: NYi Zhang <yi.zhang@redhat.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Delayed keep alive work is queued on system workqueue and may be cancelled
via nvme_stop_keep_alive from nvme_reset_wq, nvme_fc_wq or nvme_wq.

Check_flush_dependency detects mismatched attributes between the work-queue
context used to cancel the keep alive work and system-wq. Specifically
system-wq does not have the WQ_MEM_RECLAIM flag, whereas the contexts used
to cancel keep alive work have WQ_MEM_RECLAIM flag.

Example warning:

  workqueue: WQ_MEM_RECLAIM nvme-reset-wq:nvme_fc_reset_ctrl_work [nvme_fc]
	is flushing !WQ_MEM_RECLAIM events:nvme_keep_alive_work [nvme_core]

To avoid the flags mismatch, delayed keep alive work is queued on nvme_wq.

However this creates a secondary concern where work and a request to cancel
that work may be in the same work queue - namely err_work in the rdma and
tcp transports, which will want to flush/cancel the keep alive work which
will now be on nvme_wq.

After reviewing the transports, it looks like err_work can be moved to
nvme_reset_wq. In fact that aligns them better with transition into
RESETTING and performing related reset work in nvme_reset_wq.

Change nvme-rdma and nvme-tcp to perform err_work in nvme_reset_wq.
Signed-off-by: NNigel Kirkland <nigel.kirkland@broadcom.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Decode interrupted command and not ready namespace nvme status codes to
BLK_STS_TARGET. These are not generic IO errors and should use a non-path
specific error so that it can use the non-failover retry path.
Reported-by: NJohn Meneghini <John.Meneghini@netapp.com>
Cc: Hannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Despite NVM Express specification 1.3 requires a controller claiming to
be 1.3 or higher implement Identify CNS 03h (Namespace Identification
Descriptor list), the driver doesn't really need this identification in
order to use a namespace. The code had already documented in comments
that we're not to consider an error to this command.

Return success if the controller provided any response to an
namespace identification descriptors command.

Fixes: 538af88e ("nvme: make nvme_report_ns_ids propagate error back")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205679Reported-by: NIngo Brunberg <ingo_brunberg@web.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: stable@vger.kernel.org # 5.4+
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Since e045fa29 ("PCI/MSI: Fix incorrect MSI-X masking on resume") is
merged, we can revert the previous quirk now.

This reverts commit 19ea025e.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=204887
Fixes: 19ea025e ("nvme: Add quirk for Kingston NVME SSD running FW E8FK11.T")
Link: https://lore.kernel.org/r/20191031093408.9322-1-jian-hong@endlessm.comSigned-off-by: NJian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org

We've seen a few devices that return different controller id's to
the Fabric Connect command vs the Identify(controller) command. It's
currently hard to identify this failure by existing error messages. It
comes across as a (re)connect attempt in the transport that fails with
a -22 (-EINVAL) status. The issue is compounded by older kernels not
having the controller id check or had the identify command overwrite the
fabrics controller id value before it checked. Both resulted in cases
where the devices appeared fine until more recent kernels.

Clarify the reject by adding an error message on controller id mismatches.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Users observe IOMMU related errors when performing discard on nvme from
non-compliant nvme devices reading beyond the end of the DMA mapped
ranges to discard.

Two different variants of this behavior have been observed: SM22XX
controllers round up the read size to a multiple of 512 bytes, and Phison
E12 unconditionally reads the maximum discard size allowed by the spec
(256 segments or 4kB).

Make nvme_setup_discard unconditionally allocate the maximum DSM buffer
so the driver DMA maps a memory range that will always succeed.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202665 many
Signed-off-by: NEduard Hasenleithner <eduard@hasenleithner.at>
[changelog, use existing define, kernel coding style]
Signed-off-by: NKeith Busch <kbusch@kernel.org>

nvme devices report temperature information in the controller information
(for limits) and in the smart log. Currently, the only means to retrieve
this information is the nvme command line interface, which requires
super-user privileges.

At the same time, it would be desirable to be able to use NVMe temperature
information for thermal control.

This patch adds support to read NVMe temperatures from the kernel using the
hwmon API and adds temperature zones for NVMe drives. The thermal subsystem
can use this information to set thermal policies, and userspace can access
it using libsensors and/or the "sensors" command.

Example output from the "sensors" command:

nvme0-pci-0100
Adapter: PCI adapter
Composite:    +39.0°C  (high = +85.0°C, crit = +85.0°C)
Sensor 1:     +39.0°C
Sensor 2:     +41.0°C
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NKeith Busch <kbusch@kernel.org>

Introduce the new helper function nvme_lba_to_sect() to convert a device
logical block number to a 512B sector number. Use this new helper in
obvious places, cleaning up the code.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Rename nvme_block_nr() to nvme_sect_to_lba() and use SECTOR_SHIFT
instead of its hard coded value 9. Also add a comment to decribe this
helper.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

nvme_cleanup_cmd should be called for each call to nvme_setup_cmd
(symmetrical functions). Move the call for nvme_cleanup_cmd to the common
core layer and call it during nvme_complete_rq for the good flow. For
error flow, each transport will call nvme_cleanup_cmd independently. Also
take care of a special case of path failure, where we call
nvme_complete_rq without doing nvme_setup_cmd.
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix the status code of canceled requests initiated by the host according
to TP4028 (Status Code 0x371):
"Command Aborted By host: The command was aborted as a result of host
action (e.g., the host disconnected the Fabric connection)."

Also in a multipath environment, unless otherwise specified, errors of
this type (path related) should be retried using a different path, if
one is available.
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The .ioctl and .compat_ioctl file operations have the same prototype so
they can both point to the same function, which works great almost all
the time when all the commands are compatible.

One exception is the s390 architecture, where a compat pointer is only
31 bit wide, and converting it into a 64-bit pointer requires calling
compat_ptr(). Most drivers here will never run in s390, but since we now
have a generic helper for it, it's easy enough to use it consistently.

I double-checked all these drivers to ensure that all ioctl arguments
are used as pointers or are ignored, but are not interpreted as integer
values.
Acked-by: NJason Gunthorpe <jgg@mellanox.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NDavid Sterba <dsterba@suse.com>
Acked-by: NDarren Hart (VMware) <dvhart@infradead.org>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>