scsi: snic: Fix memory leak with using debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.

Link: https://lore.kernel.org/r/20230202141009.2290380-1-gregkh@linuxfoundation.org
Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 2)

Based on the normalized pattern:

this program is free software you may redistribute it and/or modify it
under the terms of the gnu general public license as published by the
free software foundation version 2 of the license the software is
provided as is without warranty of any kind express or implied
including but not limited to the warranties of merchantability fitness
for a particular purpose and noninfringement in no event shall the
authors or copyright holders be liable for any claim damages or other
liability whether in an action of contract tort or otherwise arising
from out of or in connection with the software or the use or other
dealings in the software

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: snic: debugfs: remove local storage of debugfs files

There is no need to keep the dentry around for the debugfs trace files,
as we can just look it up when we want to remove it later on. Simplify
the structure by removing the dentries and relying on debugfs to find
the dentry to remove when we want to.

By doing this change, we remove the last in-kernel user that was storing
the result of debugfs_create_bool(), so that api can be cleaned up.

Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>
Link: https://lore.kernel.org/r/20210518161625.3696996-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: snic: Convert to DEFINE_SHOW_ATTRIBUTE()

Use DEFINE_SHOW_ATTRIBUTE() macro to simplify the code.

Link: https://lore.kernel.org/r/20210331065326.18804-1-dingsenjie@163.com
Signed-off-by: dingsenjie <dingsenjie@yulong.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: snic: Convert to use DEFINE_SEQ_ATTRIBUTE macro

Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.

Link: https://lore.kernel.org/r/20200916025030.3992991-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: snic: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the return
value. The function can work or not, but the code logic should never do
something different based on this.

Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: snic: fix printing time intervals

We don't want to use 'struct timespec' because of the y2038 overflow
problem. The overflow is not actually an issue here, but it's easy to
replace with 'timespec64' for consistency. However, it's worth pointing out
that nanosecond values have nine digits, not eight or ten, so I'm fixing
the format strings accordingly as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: snic: fix spelling mistake: "Cann't" -> "Cannot"

Trivial fix to spelling mistake in SNIC_ERR error message text, one
cannot have "Cann't".

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

snic: Added additional stats

Adding additional stats, and fixed logging messages.
- Added qdepth change stats
- Added separate isr stats for each type of interrupt
- Fixed race in updating active IOs
- Suppressed Link event message for DAS backend.

Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

snic: driver for Cisco SCSI HBA

Cisco has developed a new PCI HBA interface called sNIC, which stands for
SCSI NIC. This is a new storage feature supported on specialized network
adapter. The new PCI function provides a uniform host interface and abstracts
backend storage.

[jejb: fix up checkpatch errors]
Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>