Test Case: FreeBSD NFSv3 Export Basic Functionality

Test ID: TC131-nfs-export-basic Category: NFS Export Priority: Critical Regression: EROFS VOP_VPTOFH / VFS_FHTOVP / export updates

Objective

Verify that FreeBSD 15 mountd can install an export on a read-only EROFS mount, that nfsd can resolve EROFS file handles, and that regular files, directories, symlinks, and FIFOs are visible through a real NFSv3 client.

Preconditions

FreeBSD 15 amd64 server/client, optionally the same host over loopback.
Root privilege for module, md, NFS service, getfh, and fhopen operations.
erofs.ko, test-nfs.erofs, and tests/nfs_fh_tool.c available in the guest.
The fixture contains basic/regular.txt, basic/subdir, basic/link-to-regular, and basic/test.fifo.

Procedure

Build the module and helper:

./build.sh
cc -O2 -Wall -Wextra -std=c17 tests/nfs_fh_tool.c -o nfs_fh_tool

Load and mount EROFS on a fixed md unit:

kldload ./erofs.ko
mdconfig -a -t vnode -f test-nfs.erofs -u 42
mkdir -p /mnt/repo22-erofs
mount -t erofs -o ro /dev/md42 /mnt/repo22-erofs
mount -v | grep /mnt/repo22-erofs

The line must show read-only and must not show NFS exported before mountd processes /etc/exports.

Configure the real FreeBSD mountd/nfsd flow:

cp -p /etc/exports /tmp/exports.before 2>/dev/null || true
printf '%s\n' \
  '/mnt/repo22-erofs -ro -maproot=root -network 127.0.0.0 -mask 255.0.0.0' \
  > /etc/exports
service rpcbind onestart
service mountd onestart
service nfsd onestart
service mountd onereload
rpcinfo -p 127.0.0.1
showmount -e 127.0.0.1
mount -v | grep /mnt/repo22-erofs

After reload, the EROFS mount line must show NFS exported. The flag is installed by the generic FreeBSD export layer after the filesystem accepts the export-only MNT_UPDATE; EROFS must not set it during the initial mount.

Mount the export through NFSv3 and confirm the negotiated options:

mkdir -p /mnt/repo22-nfs
mount_nfs -o nfsv3,tcp,rdirplus 127.0.0.1:/mnt/repo22-erofs \
  /mnt/repo22-nfs
nfsstat -m

Verify all required vnode types and read-only behavior:

cmp /mnt/repo22-nfs/basic/regular.txt \
  /mnt/repo22-erofs/basic/regular.txt
test -d /mnt/repo22-nfs/basic/subdir
test "$(readlink /mnt/repo22-nfs/basic/link-to-regular)" = regular.txt
test -p /mnt/repo22-nfs/basic/test.fifo
test "$(stat -f %i /mnt/repo22-nfs/basic/regular.txt)" = \
  "$(stat -f %i /mnt/repo22-erofs/basic/regular.txt)"
! touch /mnt/repo22-nfs/write-must-fail

Exercise both shared- and exclusive-lock file-handle resolution locally:

./nfs_fh_tool capture /mnt/repo22-erofs/basic/regular.txt regular.fh
./nfs_fh_tool stat regular.fh
./nfs_fh_tool cat regular.fh regular.out
cmp regular.out /mnt/repo22-erofs/basic/regular.txt

fhstat requests a shared lock and fhopen requests an exclusive lock.

Confirm that NFSv3 used READDIRPLUS and did not issue writes:
```
nfsstat -c
nfsstat -s
```

Expected Results

mountd accepts the EROFS export-only update.
showmount -e lists the EROFS path and mount -v shows NFS exported only after mountd reloads exports.
NFSv3 regular reads, directory traversal, symlink lookup, FIFO metadata, and inode numbers match the direct EROFS mount.
Writes fail with EROFS/Read-only file system.
fhstat and fhopen both resolve the same 64-bit EROFS NID.
NFS statistics show READDIRPLUS traffic and zero successful write RPCs.

Cleanup

Always remove clients before stopping the loopback server:

umount /mnt/repo22-nfs
: > /etc/exports
service mountd onereload
service nfsd onestop
service mountd onestop
service rpcbind onestop
umount /mnt/repo22-erofs
mdconfig -d -u 42
kldunload erofs
rm -f /etc/exports

Restore a pre-existing /etc/exports instead of removing it when applicable.

Notes

The EROFS FreeBSD file-handle payload is 16 bytes: len, pad, nid_hi, nid_lo, and a nonzero superblock-seeded per-inode generation matching va_gen.
Do not use Linux exportfs; FreeBSD mountd installs exports through a mount update carrying the export option.
Throughput is recorded for information only; correctness has no fixed MB/s threshold.

4.3 KiB Raw Blame History