Linux: allow mounting NTFS volumes with ntfs3

[mammothcoding]

Summary

This PR allows Linux users to mount NTFS volumes with the in-kernel ntfs3 driver instead of ntfs-3g/fuseblk.

It intentionally does not add sleep hooks, automatic dismounting, or arbitrary filesystem type passthrough. It adds a narrow Linux-only ntfs3 path for NTFS volumes.

Motivation

This is related to #1660.

On recent Linux/systemd combinations, NTFS VeraCrypt volumes mounted through ntfs-3g appear as fuseblk. During suspend/hibernate, systemd may freeze user.slice while the kernel sleep path tries to sync FUSE-backed filesystems. If the userspace ntfs-3g daemon is frozen, the sleep path can hang.

Mounting the NTFS filesystem with the Linux in-kernel ntfs3 driver avoids the FUSE userspace daemon path.

What changed

• Accept ntfs3 as a valid Linux value for --filesystem.
• Canonicalize the explicit mount filesystem type to lowercase ntfs3.
• Keep the existing VolumeCreationOptions::FilesystemType::NTFS mapping, because ntfs3 is a Linux mount driver for the NTFS filesystem, not a separate on-disk format.
• Add a Linux preference named "Mount NTFS volumes with the Linux kernel ntfs3 driver".
• When that preference is enabled, detect NTFS filesystems with blkid and mount them with ntfs3 automatically. This applies to the Linux native dm-crypt path and to the fallback auxiliary-image mount path.
• Make the preference apply to favorite volumes, because favorites use the default mount options.
• Document in command-line help, GUI preference text, and the HTML documentation that the ntfs3 kernel module must be available and allowed by the distribution. Some distributions blacklist it by default and require administrator action before it can be loaded.
• Add a Linux help example for mounting an NTFS volume using --filesystem=ntfs3.

Local validation

I reproduced the affected setup on openSUSE Tumbleweed with:

• Kernel: 6.19.11-1-default
• systemd: 259.5+suse
• VeraCrypt: 1.26.24
• ntfs-3g: 2022.10.3
• fuse3: 3.18.2

The affected NTFS VeraCrypt volume previously mounted as fuseblk and hibernation could hang. I then opened the VeraCrypt volume without mounting its filesystem and mounted the virtual device with:

mount -t ntfs3 -o uid=1000,gid=1000,umask=077 /dev/mapper/veracrypt1 /home/myuser/SecVol

findmnt then reported:

/home/myuser/SecVol /dev/mapper/veracrypt1 ntfs3

With the VeraCrypt volume left mounted as ntfs3, hibernation and resume completed successfully and the volume remained mounted after resume.

Patched binary validation:

• Built successfully on the same openSUSE Tumbleweed system with make NOGUI=1.
• Built successfully on the same system with the default GUI build (make).
• veracrypt --text --help includes the new ntfs3 help text and example.
• --filesystem=ntfs3 is accepted by the command-line parser.
• An arbitrary filesystem value such as --filesystem=definitely-not-allowed is still rejected as an unknown option.

Live patched-binary mount validation:

• Mounted the same NTFS VeraCrypt volume through the patched binary using --filesystem=ntfs3.
• findmnt reported the mounted filesystem as ntfs3 on /dev/mapper/veracrypt1.
• The volume remained visible to VeraCrypt in its normal slot after the filesystem mount.

Favorite-volume validation:

• Enabled the new MountNtfsWithNtfs3 preference.
• Mounted the same NTFS VeraCrypt volume through --load-preferences --auto-mount favorites; findmnt reported ntfs3.
• Mounted the same favorite volume through the GUI menu Favorites -> Mount Favorite Volumes; findmnt reported ntfs3.
• With the GUI-mounted favorite volume left mounted as ntfs3, hibernation and resume completed successfully and the volume remained mounted after resume.

[idrassi]

@mammothcoding
Thanks for the detailed testing and for keeping the PR narrow.

Your results are useful confirmation for #1660 conclusion.

I agree with the general direction of this P but I can't merge it as-is. Please revise the following:

1. Gate the new GUI preference strictly to Linux. The persistence and mount behavior are Linux-only but the checkbox and
   help text are currently added in the shared wx UI path. Non-Linux Unix builds should not expose a Linux-only ntfs3 option.

2. Avoid duplicating DetectFilesystemType in both CoreUnix.cpp and CoreLinux.cpp. Please consolidate it into one Linux helper or otherwise avoid duplicated logic.

3. Make the NTFS detection use uncached probing, e.g. blkid -p -o value -s TYPE -- <device>, because VeraCrypt
   reuses /dev/mapper/veracryptN device names.

4. Clarify the documentation/help text around detection and fallback. The preference should be described as applying only when VeraCrypt detects NTFS via blkid. If detection fails or if ntfs3 is unavailable, users should not be left with the impression that the FUSE path was definitely avoided.

5. Keep this opt-in and disabled by default. Linux NTFS mounts can use different backends depending on kernel, installed packages and distribution policy (ntfs-3g/fuseblk, lowntfs-3g, ntfs3 and possibly newer kernel ntfs implementations). VeraCrypt shouldn't override the default NTFS backend for existing users unless they explicitly opt in.

Once these points are addressed, this can be considered as an opt-in mitigation for affected Linux users.

[mammothcoding]

Thanks for the note about translation changes. I removed the Russian language and Russian documentation updates from this PR in 2411942, so this PR now keeps only the code changes plus English strings/docs. If this PR is accepted, I can follow up with a separate Russian translation PR based on the final English text.

[idrassi]

@mammothcoding Thanks for the changes. I did a small update to add new entries to XML language files to make Validate XML pass