Date: Fri, 02 Jan 2026 06:34:12 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 292120] ZFS filesystem jailed and mounted causes the jail to get stuck in dying state Message-ID: <bug-292120-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=292120 Bug ID: 292120 Summary: ZFS filesystem jailed and mounted causes the jail to get stuck in dying state Product: Base System Version: 15.0-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: ab@astral.blue ## Synopsis When a jailed ZFS filesystem is mounted inside, the jail gets stuck in dying state upon removal. ## To reproduce Prepare a bare-bone test jail filesystem, say in /j: $ mkdir -p /j && find -d /etc/pkg/ /usr/local/etc/pkg/ /usr/share/keys/*/trusted/ -print0 | cpio -pdum0 --quiet /j && pkg -r /j install -r FreeBSD-base -qy FreeBSD-runtime FreeBSD-zfs Create a test filesystem zroot/j1 with jailed=on: $ zfs create -o jailed=on -o mountpoint=/j1 zroot/j1 Launch a test jail with zroot/j1 injected, and list the dataset from inside jail: $ jail -c name=j path=/j mount.devfs allow.mount allow.mount.zfs enforce_statfs=1 zfs.dataset=zroot/j1 command=zfs list zroot/j1 NAME USED AVAIL REFER MOUNTPOINT zroot/j1 96K 429G 96K /j1 Ensure that the jail has been removed (expected behavior): $ jls -d jid name path Launch another test jail, but this time mount zroot/j1 from inside: $ jail -c name=j path=/j mount.devfs allow.mount allow.mount.zfs enforce_statfs=1 zfs.dataset=zroot/j1 command=zfs mount zroot/j1 See that the jail is stuck in dying state: $ jls jid name path # j is missing $ jls -d jid name path # j is shown (it's dying) 38 j /j Try to unjail the filesystem - it fails: $ zfs unjail j zroot/j1 invalid jail id or name ... $ zfs unjail 38 zroot/j1 invalid jail id or name ... $ jls -d jid name path # j is still there 38 j /j Try to unmount the filesystem: $ zfs unmount zroot/j1 # seems to succeed but... $ zfs get mounted zroot/j1 # it is still mounted NAME PROPERTY VALUE SOURCE zroot/j1 mounted yes - $ jls -d jid name path # j is still there 38 j /j ## Workarounds Destroying zroot/j1 causes the jail to be removed but it's impractical in most use cases of jailed ZFS. Resetting jailed property (zfs inherit jailed zroot/j1) TWICE also removes the jail, but this is dangerous because it mounts the filesystem at the untrusted in-jail mountpoint if it has one. The mountpoint property cannot be set or reset/inherited from the host side while it is jailed, with a "dataset in a non-global zone" error. -- You are receiving this mail because: You are the assignee for the bug.home | help
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