Date:   Mon, 13 Mar 2023 16:01:54 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <linux-kernel@vger.kernel.org>
CC:     <rafael@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Alex Shi <alexs@kernel.org>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Alexandre Bounine <alex.bou9@gmail.com>,
        Alison Schofield <alison.schofield@intel.com>,
        "Ben Widawsky" <bwidawsk@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "Dan Williams" <dan.j.williams@intel.com>,
        Dexuan Cui <decui@microsoft.com>,
        "Eric Dumazet" <edumazet@google.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        "Hannes Reinecke" <hare@suse.de>,
        Harald Freudenberger <freude@linux.ibm.com>,
        "Heiko Carstens" <hca@linux.ibm.com>, Hu Haowen <src.res@email.cn>,
        Ilya Dryomov <idryomov@gmail.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Iwona Winiarska <iwona.winiarska@intel.com>,
        Jakub Kicinski <kuba@kernel.org>, Jens Axboe <axboe@kernel.dk>,
        Jonathan Corbet <corbet@lwn.net>,
        Laurentiu Tudor <laurentiu.tudor@nxp.com>,
        Matt Porter <mporter@kernel.crashing.org>,
        "Michael Ellerman" <mpe@ellerman.id.au>,
        Paolo Abeni <pabeni@redhat.com>,
        Stuart Yoder <stuyoder@gmail.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Wei Liu <wei.liu@kernel.org>,
        Yanteng Si <siyanteng@loongson.cn>
Subject: Re: [PATCH 23/36] driver core: bus: mark the struct bus_type for
 sysfs callbacks as constant
Message-ID: <640fab62cdd53_239fd62942@iweiny-mobl.notmuch>
References: <20230313182918.1312597-1-gregkh@linuxfoundation.org>
 <20230313182918.1312597-23-gregkh@linuxfoundation.org>
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Greg Kroah-Hartman wrote:
> struct bus_type should never be modified in a sysfs callback as there is
> nothing in the structure to modify, and frankly, the structure is almost
> never used in a sysfs callback, so mark it as constant to allow struct
> bus_type to be moved to read-only memory.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> Cc: Alex Shi <alexs@kernel.org>
> Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> Cc: Alexandre Bounine <alex.bou9@gmail.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Ben Widawsky <bwidawsk@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Dexuan Cui <decui@microsoft.com>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Harald Freudenberger <freude@linux.ibm.com>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Hu Haowen <src.res@email.cn>
> Cc: Ilya Dryomov <idryomov@gmail.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Iwona Winiarska <iwona.winiarska@intel.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
> Cc: Matt Porter <mporter@kernel.crashing.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Stuart Yoder <stuyoder@gmail.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Cc: Yanteng Si <siyanteng@loongson.cn>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: Ira Weiny <ira.weiny@intel.com> # cxl

> ---
> Note, this is a patch that is a prepatory cleanup as part of a larger
> series of patches that is working on resolving some old driver core
> design mistakes.  It will build and apply cleanly on top of 6.3-rc2 on
> its own, but I'd prefer if I could take it through my driver-core tree
> so that the driver core changes can be taken through there for 6.4-rc1.
> 
>  Documentation/driver-api/driver-model/bus.rst |  4 +-
>  Documentation/filesystems/sysfs.rst           |  4 +-
>  .../translations/zh_CN/filesystems/sysfs.txt  |  4 +-
>  .../translations/zh_TW/filesystems/sysfs.txt  |  4 +-
>  arch/powerpc/platforms/pseries/ibmebus.c      |  4 +-
>  arch/powerpc/platforms/pseries/vio.c          |  8 ++--
>  drivers/ata/pata_parport/pata_parport.c       |  6 +--
>  drivers/base/bus.c                            |  8 ++--
>  drivers/block/rbd.c                           | 34 +++++++--------
>  drivers/bus/fsl-mc/fsl-mc-bus.c               |  6 +--
>  drivers/cxl/core/port.c                       |  2 +-
>  drivers/hv/vmbus_drv.c                        |  2 +-
>  drivers/net/netdevsim/bus.c                   |  4 +-
>  drivers/pci/pci-sysfs.c                       |  2 +-
>  drivers/pci/pci.c                             |  4 +-
>  drivers/peci/sysfs.c                          |  2 +-
>  drivers/rapidio/rio-sysfs.c                   |  2 +-
>  drivers/s390/crypto/ap_bus.c                  | 42 +++++++++----------
>  drivers/scsi/fcoe/fcoe_sysfs.c                |  8 ++--
>  drivers/scsi/fcoe/fcoe_transport.c            |  6 +--
>  include/linux/device/bus.h                    |  4 +-
>  include/scsi/libfcoe.h                        |  6 +--
>  22 files changed, 78 insertions(+), 88 deletions(-)
> 

[...]

> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 8ee6b6e2e2a4..66333cd6248e 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -1927,7 +1927,7 @@ bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd)
>  EXPORT_SYMBOL_NS_GPL(schedule_cxl_memdev_detach, CXL);
>  
>  /* for user tooling to ensure port disable work has completed */
> -static ssize_t flush_store(struct bus_type *bus, const char *buf, size_t count)
> +static ssize_t flush_store(const struct bus_type *bus, const char *buf, size_t count)
>  {
>  	if (sysfs_streq(buf, "1")) {
>  		flush_workqueue(cxl_bus_wq);