VirtualMemory preflet: lists RAM FS Volume as valid swap file storage option

[bipolar]

As per the title:

The VirtualMemory preflet shows the RAM FS volume (from /system/var/shared_memory) as an option of where to place the swap file (when auto-swap management option is off).

That seems like a recipe for problems, right? (I didn't dared to actually try it out).

Anyway.... Any suggestions on how to better filter FSes like that so they don't pop up in VirtualMemory?

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A bit of a tangent:

Seeing that VirtualMemory checks each BVolume's IsPersistent() (among other fs_info flag related methods)... and reading the Be Book, that says: "IsPersistent() - Is the storage persistent (such as on a floppy or hard disk)?"

I thought... why ramfs is setting B_FS_IS_PERSISTENT?

(In an attempt to fix the issue with the VM preflet, I've tried removing B_FS_IS_PERSISTENT from ramfs, but that cause KDLs when you attempt to write to a RAMFS you just mounted). [Note 1]

I guess "B_FS_IS_PERSISTENT/IsPersistent()" only means that an FS can store data, even if it is just temporarily?

In that case... Is there a way to check for "the other meaning" of persistent, as in... "you can reasonably expect data to survive reboots"? (seems something backup software, for example, might care about).

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Edit: [Note 1]

After a second attempt, I couldn't reproduce the KDLs after removing B_FS_IS_PERSISTENT, but doing:

mkdir ~/test_ramfs
mount -t ramsfs ~/test_ramfs
touch ~/test_ramfs/test.txt

Also creating a "New Folder" there from Tracker... Then, when attempting to remove that "test.txt" file and "New Folder" from Tracker... caused both Terminal and Tracker to hang and become unkillable.

(system wide ramfs was disabled from the boot menu when testing the modified one, of course).

[bipolar]

As per waddlesplash suggestion... proposed workaround:

​https://review.haiku-os.org/c/haiku/+/5911

[waddlesplash]

fixed in hrev56642 +beta4