Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r253476:

Add message when nvd disks are attached and detached.

As part of this commit, add an nvme_strvis() function which borrows
heavily from cam_strvis(). This will allow stripping of
leading/trailing whitespace and also handle unprintable characters
in model/serial numbers. This function goes into a new nvme_util.c
file which is used by both the driver and nvmecontrol.

Approved by: re (kib)
Sponsored by: Intel

MFC r253437:

Define constants for the lengths of the serial number, model number
and firmware revision in the controller's identify structure.

Also modify consumers of these fields to ensure they only use the
specified number of bytes for their respective fields.

Approved by: re (kib)
Sponsored by: Intel

MFC r253116:

Ensure controller or namespace node name is specified before trying to
access it.

While here, also fix the identify usage message to show the -v and -x
parameters.

Approved by: re (kib)

MFC r253115:

Condense the output for displaying LBA formats.

Approved by: re (kib)

MFC r253114:

Send per-namespace logpage commands to the controller devnode, so they
are processed as admin commands, not I/O commands.

As part of this change, pull out the code for parsing a namespace node
string into a separate function, since it is used for both identify and
logpage commands.

Approved by: re (kib)

MFC r253109, r253279:

r253109:
Incorporate feedback from bde@ based on r252672 changes:

* Use 0/1 instead of sysexits. Man pages are confusing on this topic,
but 0/1 is sufficient for nvmecontrol.
* Use err function family where possible instead of fprintf/exit.
* Fix some typing errors.
* Clean up some error message inconsistencies.

r253279:
%d should be used for printing int32_t instead of %zd.

clang does not complain about this - only gcc.

Incorporated r253279 prior to MFC timeout because it is required for gcc
builds.

Approved by: re (kib)

MFC r252275:

Add generalized helper functions for printing hex data as part of
nvmecontrol commands.

Submitted by: Joe Golio <joseph.golio@emc.com>
Obtained from: EMC / Isilon Storage Division

MFC r252274:

Ensure that a device node is specified when invoking the identify or reset
commands.

Also improve the checking of device node names, so that better error
messages are displayed when incorrect names are specified.

Sponsored by: Intel

MFC r252270:

Create #defines for NVME_CTRLR_PREFIX and NVME_NS_PREFIX for the "nvme"
and "ns" strings, rather than hardcoding the string values throughout the
nvmecontrol code base.

Sponsored by: Intel

MFC r252266:

Break out code related to the identify command into a separate source file.

Sponsored by: Intel

Break out code related to the identify command into a separate source file.

Sponsored by: Intel
MFC after: 3 days