XFS statfs free-space grossly wrong vs superblock on 6.1.148 → kubelet false disk pressure

**Image I'm using:**

Bottlerocket 1.47.0 (aws-k8s-1.32)
Kernel: 6.1.148 #1 SMP PREEMPT_DYNAMIC Mon Sep 8 23:27:00 UTC 2025 x86_64 GNU/Linux
Filesystem: XFS on /dev/nvme1n1p1 (300 GB volume)

**What I expected to happen:**

`df` / `statfs` should accurately report free/used space, consistent with the XFS superblock, so that kubelet does not incorrectly mark the node as having DiskPressure.

**What actually happened:**

`statfs` (and therefore `df` and kubelet) reports that ~250 GiB of the 300 GiB disk is used, while the XFS superblock reports only ~2.3 GiB used.
Kubelet evicts pods due to false DiskPressure.

**Examples:**

`statfs` (df / kubelet view):
```bash
findmnt -T /var/lib/kubelet
# TARGET SOURCE FSTYPE OPTIONS
# /var /dev/nvme1n1p1[/var] xfs rw,nosuid,nodev,noatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota

stat -f -c 'blocks=%b bfree=%f bavail=%a bsize=%s' /var/lib/kubelet
# blocks=78604289 bfree=12384292 bavail=12384292 bsize=4096
# → ~252 GiB used

# XFS superblock (authoritative):

xfs_db -r -c "sb 0" -c "p dblocks fdblocks" /dev/nvme1n1p1
# dblocks = 78642688
# fdblocks = 78047871
# → ~2.3 GiB used

# All mountpoints (/local, /var, /opt, /mnt) are bind-mounts of the same device.

# No large deleted-open files exist:

# PID=1851 COMM=dbus-broker-lau SIZE=2097152 FILE=/memfd:dbus-broker-log (deleted)
```

**How to reproduce the problem:**

Run a bunch of pods and they will start getting evicted:

```bash
ctr -n k8s.io containers list | wc -l
# 92
ctr -n k8s.io images | wc -l
# 25
du -sh /var/lib/containerd/io.containerd.snapshotter.v1.overlayfs
# 13G /var/lib/containerd/io.containerd.snapshotter.v1.overlayfs
du -sh /var/lib/containerd/io.containerd.content.v1.content/blobs/
# 3.5G /var/lib/containerd/io.containerd.content.v1.content/blobs/
du -sh /run/containerd/
# 54G /run/containerd/
df -h /var/lib/docker/
# Filesystem Size Used Avail Use% Mounted on
# /dev/nvme1n1p1 300G 255G 46G 85% /var
```

One more symptom - kubelet can't free up disk space:

```
usage=85 highThreshold=75 amountToFree=45866138419 lowThreshold=70
"Failed to garbage collect required amount of images. Attempted to free 45867354931 bytes, but only found 0 bytes eligible to free."
```

I can cordon and discard the node, but if I can provide any more info to catch some bug, please let me know.

No source file or test is named. Start by reproducing the statfs, df, and xfs_db discrepancy on the stated Bottlerocket and kernel environment, then trace how XFS free-space reporting reaches kubelet. Done means identifying the reporting mismatch and defining a validated correction that prevents false DiskPressure.

Written by the indexing model from the issue text.