Deadlock in ZFS @ FreeBSD 15.0-RELEASE-p3 handling of extended attributes?

I would have entered this into the freebsd bugzilla, but that seems to be down right now…

Anyway, I’m trying to copy some 30000 ZFS filesystems (home directories) on a new server running FreeBSD 15.0-RELEASE-p3. The server has 10 15TB NVMEe SSD drives configured as mirrors in one big Zpool. The copy is basically a loop over the 30000 directories and the doing a zfs create … ; tar cpf - | (cd /new/home; tar xpf -)

The first 495 directories copied without problem, but now it seems the bsdtar process writing to the new home directory has deadlocked in:


# procstat -kka|egrep bsdtar

63997 103752 bsdtar              -                   mi_switch+0xbc sleepq_catch_signals+0x27d sleepq_wait_sig+0x9 _sleep+0x197 uipc_sosend_stream_or_seqpacket+0x475 sousrsend+0x5f dofilewrite+0x81 sys_write+0x127 amd64_syscall+0x126 fast_syscall_common+0xf8

63998 290883 bsdtar              -                   mi_switch+0xbc _sleep+0x19e rms_rlock_fallback+0x90 zfs_lookup+0x74 zfs_deleteextattr_dir+0x38 zfs_setextattr+0x7dc VOP_SETEXTATTR_APV+0x24 extattr_set_vp+0x11d kern_extattr_set_path+0x14e sys_extattr_set_link+0x6b amd64_syscall+0x126 fast_syscall_common+0xf8

I’m guessing some kind of problem with the handling of extended attributes…

I created the home directory root like this:

#!/bin/sh

PROPS="\
-o atime=off \
-o relatime=on \
-o dnodesize=auto \
-o compression=zstd \
-o utf8only=on \
-o normalization=formC \
-o xattr=sa \
-o overlay=off \
-o aclmode=passthrough \
-o aclinherit=passthrough-x \
-o sharenfs=sec=krb5:krb5i:krb5p"

for ZFS in "$@"; do
    zfs create $PROPS "$ZFS"
done


- Peter