linux.git/drivers/nvme/target/admin-cmd.c, branch v5.16

nvmet: use flex_array_size and struct_size

2021-10-27T06:06:41+00:00

In an effort to avoid open-coded arithmetic in the kernel [1], use the
flex_array_size() and struct_size() helpers instead of an open-coded
calculation.

[1] https://github.com/KSPP/linux/issues/160

Signed-off-by: Len Baker 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Gustavo A. R. Silva 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: use struct_size over open coded arithmetic

2021-10-20T17:23:30+00:00

As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

In this case this is not actually dynamic size: all the operands
involved in the calculation are constant values. However it is better to
refactor this anyway, just to keep the open-coded math idiom out of
code.

So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kmalloc() function.

This code was detected with the help of Coccinelle and audited and fixed
manually.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Signed-off-by: Len Baker 
Signed-off-by: Christoph Hellwig

nvmet: use macro definitions for setting cmic value

2021-10-20T17:16:03+00:00

This makes the code more readable.

Signed-off-by: Max Gurtovoy 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: use macro definition for setting nmic value

2021-10-20T17:16:02+00:00

This makes the code more readable.

Signed-off-by: Max Gurtovoy 
Reviewed-by: Keith Busch 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: set 'CNTRLTYPE' in the identify controller data

2021-10-20T17:16:02+00:00

Set the correct 'CNTRLTYPE' field in the identify controller data.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: add nvmet_is_disc_subsys() helper

2021-10-20T17:16:02+00:00

Add a helper function to determine if a given subsystem is a discovery
subsystem.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Himanshu Madhani 
Signed-off-by: Christoph Hellwig

nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req

2021-09-06T07:59:03+00:00

The target core code never needs the host-side nvme_ctrl structure.
Open code two uses of nvmet_is_passthru_req in passthru.c, and then
switch the helpers used by the core to return bool.  Also rename the
fuctions to better match their usage:

  nvmet_passthru_ctrl -> nvmet_is_passthru_subsys
  nvmet_req_passthru_ctrl -> nvmet_is_passthru_req

Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg

nvmet: use NVMET_MAX_NAMESPACES to set nn value

2021-06-21T06:34:10+00:00

For Spec regarding MNAN value:-

If the controller supports Asymmetric Namespace Access Reporting, then
this field shall be set to a non-zero value that is less than or equal
to the NN value.

Instead of using subsys->max_nsid that gets calculated dynamically,
use NVMET_MAX_NAMESPACES value to report NN. This way we will maintain
the MNAN value spec compliant with NN.

Without this patch, code results in the following error :-

[337976.409142] nvme nvme1: Invalid MNAN value 1024

Signed-off-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: add ZBD over ZNS backend support

2021-06-17T13:51:21+00:00

NVMe TP 4053 – Zoned Namespaces (ZNS) allows host software to
communicate with a non-volatile memory subsystem using zones for NVMe
protocol-based controllers. NVMeOF already support the ZNS NVMe
Protocol compliant devices on the target in the passthru mode. There
are generic zoned block devices like  Shingled Magnetic Recording (SMR)
HDDs that are not based on the NVMe protocol.

This patch adds ZNS backend support for non-ZNS zoned block devices as
NVMeOF targets.

This support includes implementing the new command set NVME_CSI_ZNS,
adding different command handlers for ZNS command set such as NVMe
Identify Controller, NVMe Identify Namespace, NVMe Zone Append,
NVMe Zone Management Send and NVMe Zone Management Receive.

With the new command set identifier, we also update the target command
effects logs to reflect the ZNS compliant commands.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Damien Le Moal 
Signed-off-by: Christoph Hellwig

nvmet: add Command Set Identifier support

2021-06-17T13:51:20+00:00

NVMe TP 4056 allows controllers to support different command sets.
NVMeoF target currently only supports namespaces that contain
traditional logical blocks that may be randomly read and written. In
some applications there is a value in exposing namespaces that contain
logical blocks that have special access rules (e.g. sequentially write
required namespace such as Zoned Namespace (ZNS)).

In order to support the Zoned Block Devices (ZBD) backend, controllers
need to have support for ZNS Command Set Identifier (CSI).

In this preparation patch, we adjust the code such that it can now
support the default command set identifier. We update the namespace data
structure to store the CSI value which defaults to NVME_CSI_NVM
that represents traditional logical blocks namespace type.

The CSI support is required to implement the ZBD backend for NVMeOF
with host side NVMe ZNS interface, since ZNS commands belong to
the different command set than the default one.

Signed-off-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig