It's rude to crash the system just because the developer did something
wrong, as it prevents them from usually even seeing what went wrong.

So convert the few BUG_ON() calls that have snuck into the sysfs code
over the years to WARN_ON() to make it more "friendly".  All of these
are able to be recovered from, so it makes no sense to crash.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Let the passed in array be const (and thus placed in rodata) instead of
a mutable array of const pointers.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181004143750.30880-1-jani.nikula@intel.com

Pull driver core updates from Greg KH:
 "Here are all of the driver core and related patches for 4.19-rc1.

  Nothing huge here, just a number of small cleanups and the ability to
  now stop the deferred probing after init happens.

  All of these have been in linux-next for a while with only a merge
  issue reported"

* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
  base: core: Remove WARN_ON from link dependencies check
  drivers/base: stop new probing during shutdown
  drivers: core: Remove glue dirs from sysfs earlier
  driver core: remove unnecessary function extern declare
  sysfs.h: fix non-kernel-doc comment
  PM / Domains: Stop deferring probe at the end of initcall
  iommu: Remove IOMMU_OF_DECLARE
  iommu: Stop deferring probe at end of initcalls
  pinctrl: Support stopping deferred probe after initcalls
  dt-bindings: pinctrl: add a 'pinctrl-use-default' property
  driver core: allow stopping deferred probe after init
  driver core: add a debugfs entry to show deferred devices
  sysfs: Fix internal_create_group() for named group updates
  base: fix order of OF initialization
  linux/device.h: fix kernel-doc notation warning
  Documentation: update firmware loader fallback reference
  kobject: Replace strncpy with memcpy
  drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
  kernfs: Replace strncpy with memcpy
  device: Add #define dev_fmt similar to #define pr_fmt
  ...

Pull SCSI updates from James Bottomley:
 "This is mostly updates to the usual drivers: mpt3sas, lpfc, qla2xxx,
  hisi_sas, smartpqi, megaraid_sas, arcmsr.

  In addition, with the continuing absence of Nic we have target updates
  for tcmu and target core (all with reviews and acks).

  The biggest observable change is going to be that we're (again) trying
  to switch to mulitqueue as the default (a user can still override the
  setting on the kernel command line).

  Other major core stuff is the removal of the remaining Microchannel
  drivers, an update of the internal timers and some reworks of
  completion and result handling"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (203 commits)
  scsi: core: use blk_mq_run_hw_queues in scsi_kick_queue
  scsi: ufs: remove unnecessary query(DM) UPIU trace
  scsi: qla2xxx: Fix issue reported by static checker for qla2x00_els_dcmd2_sp_done()
  scsi: aacraid: Spelling fix in comment
  scsi: mpt3sas: Fix calltrace observed while running IO & reset
  scsi: aic94xx: fix an error code in aic94xx_init()
  scsi: st: remove redundant pointer STbuffer
  scsi: qla2xxx: Update driver version to 10.00.00.08-k
  scsi: qla2xxx: Migrate NVME N2N handling into state machine
  scsi: qla2xxx: Save frame payload size from ICB
  scsi: qla2xxx: Fix stalled relogin
  scsi: qla2xxx: Fix race between switch cmd completion and timeout
  scsi: qla2xxx: Fix Management Server NPort handle reservation logic
  scsi: qla2xxx: Flush mailbox commands on chip reset
  scsi: qla2xxx: Fix unintended Logout
  scsi: qla2xxx: Fix session state stuck in Get Port DB
  scsi: qla2xxx: Fix redundant fc_rport registration
  scsi: qla2xxx: Silent erroneous message
  scsi: qla2xxx: Prevent sysfs access when chip is down
  scsi: qla2xxx: Add longer window for chip reset
  ...

Introduce these two functions and export them such that the next patch
can add calls to these functions from the SCSI core.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Commit 5f81880d5204 ("sysfs, kobject: allow creating kobject belonging
to arbitrary users") incorrectly changed the argument passed as the
parent parameter when calling sysfs_add_file_mode_ns(). This caused some
sysfs attribute files to not be added correctly to certain groups.

Fixes: 5f81880d5204 ("sysfs, kobject: allow creating kobject belonging to arbitrary users")
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Normally kobjects and their sysfs representation belong to global root,
however it is not necessarily the case for objects in separate namespaces.
For example, objects in separate network namespace logically belong to the
container's root and not global root.

This change lays groundwork for allowing network namespace objects
ownership to be transferred to container's root user by defining
get_ownership() callback in ktype structure and using it in sysfs code to
retrieve desired uid/gid when creating sysfs objects for given kobject.

Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.

When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.

Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are a couple of problems with named group updates in the code
today:

* sysfs_update_group() will always fail for a named group, because
  internal_create_group() will try to create a new sysfs directory
  unconditionally, which will ofcourse fail with -EEXIST.

* We can leak the kernfs_node for grp->name if some one tries to:
  - rename a group (change grp->name), or
  - update a named group, to an unnamed group

It appears that the whole purpose of sysfs_update_group() was to
allow changing the permissions or visibility of attributes and not
the names. So make it clear in the comments, and allow it to update
an existing named group.

Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

new_sb is left uninitialized in case of early failures in kernfs_mount_ns(),
and while IS_ERR(root) is true in all such cases, using IS_ERR(root) || !new_sb
is not a solution - IS_ERR(root) is true in some cases when new_sb is true.

Make sure new_sb is initialized (and matches the reality) in all cases and
fix the condition for dropping kobj reference - we want it done precisely
in those situations where the reference has not been transferred into a new
super_block instance.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>