Reference leak affecting all fusefs dentries

[dean-deng]

Fusefs is built on top of kernfs, which currently does not release references on dentries obtained during Lookup() until they are invalidated (see kernfs.Filesystem.revalidateChildLocked). Fusefs dentries are never invalidated.

[ayushr2]

Yeah I have been looking at this. I will be addressing this in one of my upcoming changes. The issue is that currently all Inodes that inherit InodeNotDirectory are always valid by default:

gvisor/pkg/sentry/fsimpl/kernfs/inode_impl_util.go

Lines 149 to 151 in 0a7075f

	func (InodeNotDirectory) Valid(context.Context) bool {
	return true
	}

Even /proc/[pid]/fd{info}/[fd] inodes are always valid when they should be able to be invalidated.

[ayushr2]

As discussed with @mrahatm offline, the fuse bug is a different one. Unassigning myself

[mrahatm]

This one is slightly different from the procfs case. Here, the real bug is fusefs shouldn't implement dynamic dentries (i.e. Lookup() should always return nil).

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This issue is stale because it has been open 90 days with no activity. Remove the stale label or comment or this will be closed in 30 days.

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove the stale label or comment or this will be closed in 30 days.