newfs_msdos: fix build on non-FreeBSD systems

Disable data area alignment if the build environment does not define
PAGE_SIZE (e.g., when building on Linux or macOS).

Reported by: jrtc27
MFC after: 1 week

newfs_msdos: align data area to VM page boundary by default

Without alignment, the data area will not be aligned with the buffer
cache, leading to overhead, higher write multiplication on SSD devices
and issues with very large cluster sizes (see PR 277414).

The -A option used to align the start of the root directory to a
multiple of the cluster size, which happens to align the start of the
data area with a buffer page boundary in case of large clusters and
the default number of directory entries (512 entries requiring 16 KB
for FAT12 or FAT16, FAT32 puts the root directory into the data area).

This commit aligns the start of the data area with the page size, if
neither -A nor -r is used. It changes -A to align the start of the
data area (end of the root directory) to a multiple of the cluster
size, since this is the alignment that prevents write multiplication
due to clusters crossing erase block boundaries of a SSD device.
The -r option is unchanged and will prevent any automatic alignment
from occuring.

Approved by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D45436

Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

newfs_msdos: Fix warnings that arise when compiled for makefs

MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

newfs_msdos: fix type of kern.maxphys

The type of the kern.maxphys sysctl OID is now ulong. Change the
local variable type to match.

Reviewed by: delphij, emaste
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D34116

Use KERN_MAXPHYS.

Suggested by: imp
Reviewed by: imp, cem (earlier version), emaste
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25563

Gather writes to larger chunks (MAXPHYS) instead of issuing them in
sectors.

On my SanDisk Cruzer Blade 16GB USB stick this made formatting much faster:

x before
+ after
+--------------------------------------------------------------------------+
|+ |
|+ x |
|+ x x|
|A MA||
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 15.89 16.38 16 16.09 0.2570992
+ 3 0.32 0.37 0.35 0.34666667 0.025166115
Difference at 95.0% confidence
-15.7433 +/- 0.414029
-97.8455% +/- 0.25668%
(Student's t, pooled s = 0.182665)

Reviewed by: emaste
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D24508

Allow bootstrapping makefs on older FreeBSD hosts and Linux/macOS

In order to do so we need to install the msdosfs headers to the bootstrap
sysroot and avoid includes of kernel headers that may not exist on every
host (e.g. sys/lockmgr.h). This change should allow bootstrapping of makefs
on FreeBSD 11+ as well as Linux and macOS.

We also have to avoid using the IO_SYNC macro since that may not be
available. In makefs it is only used to switch between calling
bwrite() and bdwrite() which both call the same function. Therefore we
can simply always call bwrite().

For our CheriBSD builds we always bootstrap makefs by setting
LOCAL_XTOOL_DIRS='lib/libnetbsd usr.sbin/makefs' and use the makefs binary
from the build tree to create a bootable disk image.

Reviewed By: brooks
Differential Revision: https://reviews.freebsd.org/D23201

Fix a couple of minor issues with newfs_msdos:

- Do not unnecessarily strdup().
- Check return value of getdiskinfo(), if it failed, bail out.

Reviewed by: imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22729

makefs: avoid warning when creating FAT filesystem on existing file

Previously the mkfs_msdos function (from newfs_msdos) emitted warnings
in the case that an image size is specified and the target is not a
file, or no size is specified and the target is not a character device.
The latter warning (not a character device) doesn't make sense when this
code is used in makefs, regardless of whether an image size is specified
or not.

Sponsored by: The FreeBSD Foundation

When creating a new FAT32 filesystem, use "unknown" (0xFFFFFFFF) for
FSI_Nxt_Free instead of providing a wrong value.

With this change, fsck_msdosfs would no longer complain about invalid
FSInfo information.

MFC after: 2 weeks

Added option to cluster-align the start of the root directory.

Obtained from: Android
Obtained from: https://android.googlesource.com/platform/system/core/+/052f27562154d175267999106bd6bf18fc8c363e
Obtained from: https://android.googlesource.com/platform/system/core/+/8218b6aae9cd4a19fa074a8a8203fe9275b35447
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D15672

Only call close if fd and fd1 are not -1.

CID: 1384018, 1384017

Close fd and fd1 before returning now that we're done with them.

CID: 978234, 978236

newfs_msdos: add -T (timestamp) option for reproducible builds

This includes some whitespace and minor bug fixes relative to NetBSD,
which will be submitted upstream at the conclusion of the makefs
msdos update.

NetBSD revs:
mkfs_msdos.c 1.11
mkfs_msdos.h 1.4
newfs_msdos.8 1.22
newfs_msdos.c 1.44

Submitted by: Siva Mahadevan <smahadevan@freebsdfoundation.org>
Reviewed by: emaste
Obtained from: NetBSD
Sponsored by: The FreeBSD Foundation

The code only converts from bpbHugeSectors to bpbSectors if the sum of
the hidden and huge sectors is less than or equal MAXU16. When
formatting in Windows bpbSectors is still used for 63488 sectors and
2048 hidden (sum > MAXU16). The hidden sectors count is the number of
sectors before the FAT16 Boot Record so it shouldn't affect the sector
count. Attached patch (huge_sec_conversion.patch) to only check for
bpb.bpbHugeSectors <= MAXU16 when converting to bpbSectors.

Submitted by: Guy Yur
PR: 183234

Remove CHS alignment. It's not needed and causes problems for the BBB
boot partition. NetBSD removed it in 1.10 in their repo some time ago.

Submitted by: Guy Yur
PR: 183234

Use nitems() from sys/param.h.

MFC after: 2 weeks.

Fix leak in mkfs_msdos(..) by initializing img to NULL and free'ing at the end
of the function

Differential Revision: https://reviews.freebsd.org/D4405
MFC after: 1 week
PR: 204943
Reviewed by: emaste, jilles
Reported by: David Binderman <dcb314@hotmail.com>
Sponsored by: EMC / Isilon Storage Division

mkfs_msdos: sync with NetBSD

Add a sanity test and clean up whitespace.

Obtained from: NetBSD

newfs_msdos: rework error handling for eventual use in makefs

Return -1 on errors from mkfs_msdos() instead of err()/errx(), to
allow different consumers to handle errors as appropriate.

Obtained from: NetBSD
Sponsored by: The FreeBSD Foundation

newfs_msdos: prefer snprintf to sprintf

Obtained from: NetBSD
Sponsored by: The FreeBSD Foundation

newfs_msdos: move mkfs_msdos to separate file for later use in makefs

Sponsored by: The FreeBSD Foundation