git: 00f0b99e63c3 - stable/13 - OpenZFS: Fix ZFS so that snapshots under .zfs/snapshot are NFS visible

From: Ed Maste <emaste_at_FreeBSD.org>
Date: Mon, 04 Dec 2023 21:03:42 UTC
The branch stable/13 has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=00f0b99e63c3b27174b89dae426a2d87435d991a

commit 00f0b99e63c3b27174b89dae426a2d87435d991a
Author:     rmacklem <64620010+rmacklem@users.noreply.github.com>
AuthorDate: 2023-11-28 00:31:03 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2023-12-04 21:03:30 +0000

    OpenZFS: Fix ZFS so that snapshots under .zfs/snapshot are NFS visible
    
    Call vfs_exjail_clone() for mounts created under .zfs/snapshot
    to fill in the mnt_exjail field for the mount.  If this is not
    done, the snapshots under .zfs/snapshot with not be accessible
    over NFS.
    
    This version has the argument name in vfs.h fixed to match that
    of the name in spl_vfs.c, although it really does not matter.
    
    External-issue: https://reviews.freebsd.org/D42672
    Reviewed-by: Alexander Motin <mav@FreeBSD.org>
    Signed-off-by: Rick Macklem <rmacklem@uoguelph.ca>
    Closes #15563
    
    (cherry picked from commit 522414da3b283dada175161e49ea7f3fe46436ff)
---
 sys/contrib/openzfs/include/os/freebsd/spl/sys/vfs.h   | 2 +-
 sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c    | 9 ++++++++-
 sys/contrib/openzfs/module/os/freebsd/zfs/zfs_ctldir.c | 3 ++-
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/sys/contrib/openzfs/include/os/freebsd/spl/sys/vfs.h b/sys/contrib/openzfs/include/os/freebsd/spl/sys/vfs.h
index a432f6c56739..62986b7fc525 100644
--- a/sys/contrib/openzfs/include/os/freebsd/spl/sys/vfs.h
+++ b/sys/contrib/openzfs/include/os/freebsd/spl/sys/vfs.h
@@ -103,7 +103,7 @@ void vfs_setmntopt(vfs_t *vfsp, const char *name, const char *arg,
 void vfs_clearmntopt(vfs_t *vfsp, const char *name);
 int vfs_optionisset(const vfs_t *vfsp, const char *opt, char **argp);
 int mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype,
-    char *fspath, char *fspec, int fsflags);
+    char *fspath, char *fspec, int fsflags, vfs_t *parent_vfsp);
 
 typedef	uint64_t	vfs_feature_t;
 
diff --git a/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c b/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c
index 53ef46fb8ce5..177a059e88a1 100644
--- a/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c
+++ b/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c
@@ -120,7 +120,7 @@ vfs_optionisset(const vfs_t *vfsp, const char *opt, char **argp)
 
 int
 mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype, char *fspath,
-    char *fspec, int fsflags)
+    char *fspec, int fsflags, vfs_t *parent_vfsp)
 {
 	struct vfsconf *vfsp;
 	struct mount *mp;
@@ -220,6 +220,13 @@ mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype, char *fspath,
 	mp->mnt_opt = mp->mnt_optnew;
 	(void) VFS_STATFS(mp, &mp->mnt_stat);
 
+#ifdef VFS_SUPPORTS_EXJAIL_CLONE
+	/*
+	 * Clone the mnt_exjail credentials of the parent, as required.
+	 */
+	vfs_exjail_clone(parent_vfsp, mp);
+#endif
+
 	/*
 	 * Prevent external consumers of mount options from reading
 	 * mnt_optnew.
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_ctldir.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_ctldir.c
index cfc4bab2fa96..3c9311098696 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_ctldir.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_ctldir.c
@@ -1025,7 +1025,8 @@ zfsctl_snapdir_lookup(struct vop_lookup_args *ap)
 	    "%s/" ZFS_CTLDIR_NAME "/snapshot/%s",
 	    dvp->v_vfsp->mnt_stat.f_mntonname, name);
 
-	err = mount_snapshot(curthread, vpp, "zfs", mountpoint, fullname, 0);
+	err = mount_snapshot(curthread, vpp, "zfs", mountpoint, fullname, 0,
+	    dvp->v_vfsp);
 	kmem_free(mountpoint, mountpoint_len);
 	if (err == 0) {
 		/*