Steffen Maier 3a71f0f7a5 scsi: core: Fix early registration of sysfs attributes for scsi_device
v4.17 commit 86b87cde0b ("scsi: core: host template attribute groups")
introduced explicit sysfs_create_groups() in scsi_sysfs_add_sdev()
and sysfs_remove_groups() in __scsi_remove_device(), both for sdev_gendev,
based on a new field const struct attribute_group **sdev_groups
of struct scsi_host_template.

Commit 92c4b58b15 ("scsi: core: Register sysfs attributes earlier")
removed above explicit (de)registration of scsi_device attribute groups.
It also converted all scsi_device attributes and attribute_groups to
end up in a new field const struct attribute_group *gendev_attr_groups[6]
of struct scsi_device. However, that new field was not used anywhere.

Surprisingly, this only caused missing LLDD specific scsi_device sysfs
attributes. Whereas, scsi core attributes from scsi_sdev_attr_groups
did continue to exist because of scsi_dev_type.groups.

We separate scsi core attibutes from LLDD specific attributes.
Hence, we keep the initializing assignment scsi_dev_type =
{ .groups = scsi_sdev_attr_groups, } as this takes care of core
attributes. Without the separation, it would cause attribute double
registration due to scsi_dev_type.groups and sdev_gendev.groups.

Julian suggested to assign the sdev_groups pointer of the
scsi_host_template directly to the groups pointer of sdev_gendev.
This way we can delete the container scsi_device.gendev_attr_groups
and the loop copying each entry from hostt->sdev_groups to
sdev->gendev_attr_groups.

Alternative approaches ruled out:
Assigning gendev_attr_groups to sdev_dev has no visible effect.
Assigning sdev->gendev_attr_groups to scsi_dev_type.groups
caused scsi_device of all scsi host types to get LLDD specific
attributes of the LLDD for which the last sdev alloc happened to occur,
as that overwrote scsi_dev_type.groups,
e.g. scsi_debug had zfcp-specific scsi_device attributes.

Link: https://lore.kernel.org/r/20211026014240.4098365-1-maier@linux.ibm.com
Fixes: 92c4b58b15 ("scsi: core: Register sysfs attributes earlier")
Suggested-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-10-27 22:12:03 -04:00
2021-09-12 16:28:37 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%