Fix issues with user.update endpoint

User may have nologin shell causing the attempt to run cp in a
subprocess to fail due to failure to su to the user in question (due to
error in pam_open_session()).

After review of history for why we were subprocessing out to perform
this task, I failed to find a compelling reason why we could not simply
copy them without switching the user context.

This commit adds a new `copytree` filesystem utility that provides the
following features that are relevant to copying home directories.

1. ability to control behavior regarding whether the copy operation
will walk into child datasets. Generally this is not desired because
we have no design or provisions for creating child datasets within a
user home directory. This situation is most likely to arise when users
mistakenly set an incorrect path for a home directory, e.g.
/mnt/tank/share rather than /mnt/tank/share/wilbur

2. awareness of various ACL types on TrueNAS. We need to rigidly preserve
the permissions from the source when writing to a new destination in
case the administrator made a configuration mistake like in (1) in order
to avoid unintentional data disclosure.

3. awareness of the special .zfs directory. Some users enable snapdir
visibility. This means that conventional copy methods can end up
attempting to copy the entirety of the .zfs directory to a new path
resulting in excessive time spent copying and space usage.

4. ability to use block cloning. This speeds up the actual data copy and
reduces the amount of space used on the filesystem when the sysadmin
changes a user home directory path.

src/middlewared/middlewared/plugins/account.py

@@ -10,6 +10,7 @@
 from pathlib import Path
 from contextlib import suppress
 
+from dataclasses import asdict
 from middlewared.api import api_method
 from middlewared.api.current import *
 from middlewared.schema import accepts, Bool, Dict, Int, List, Password, Patch, returns, SID, Str
@@ -21,6 +22,7 @@
 from middlewared.utils import run, filter_list
 from middlewared.utils.crypto import generate_nt_hash, sha512_crypt
 from middlewared.utils.directoryservices.constants import DSType, DSStatus
+from middlewared.utils.filesystem.copy import copytree, CopyTreeConfig
 from middlewared.utils.nss import pwd, grp
 from middlewared.utils.nss.nss_common import NssModule
 from middlewared.utils.privilege import credential_has_full_admin, privileges_group_mapping
@@ -753,18 +755,14 @@ def do_update(self, app, audit_callback, pk, data):
         # Copy the home directory if it changed
         home_copy = False
         home_old = None
-        if (
-            has_home and
-            'home' in data and
-            data['home'] != user['home'] and
-            not data['home'].startswith(f'{user["home"]}/')
-        ):
-            if had_home:
-                home_copy = True
-                home_old = user['home']
+        if has_home and 'home' in data:
             if data.get('home_create', False):
                 data['home'] = os.path.join(data['home'], data.get('username') or user['username'])
 
+            if had_home and user['home'] != data['home']:
+                home_copy = True
+                home_old = user['home']
+
         # After this point user dict has values from data
         user.update(data)
 
@@ -1282,32 +1280,30 @@ async def setup_local_administrator(self, app, username, password, options):
 
     @private
     @job(lock=lambda args: f'copy_home_to_{args[1]}')
-    async def do_home_copy(self, job, home_old, home_new, username, new_mode, uid):
-        if home_old in DEFAULT_HOME_PATHS:
+    def do_home_copy(self, job, home_old, home_new, username, new_mode, uid):
+        if home_old in DEFAULT_HOME_PATH:
             return
 
+        # We need to set permission and strip ACL first before copying files
         if new_mode is not None:
-            perm_job = await self.middleware.call('filesystem.setperm', {
+            perm_job = self.middleware.call_sync('filesystem.setperm', {
                 'uid': uid,
                 'path': home_new,
                 'mode': new_mode,
                 'options': {'stripacl': True},
             })
         else:
-            current_mode = stat.S_IMODE((await self.middleware.call('filesystem.stat', home_old))['mode'])
-            perm_job = await self.middleware.call('filesystem.setperm', {
+            current_mode = stat.S_IMODE(self.middleware.call_sync('filesystem.stat', home_old)['mode'])
+            perm_job = self.middleware.call_sync('filesystem.setperm', {
                 'uid': uid,
                 'path': home_new,
                 'mode': f'{current_mode:03o}',
                 'options': {'stripacl': True},
             })
 
-        await perm_job.wait()
+        perm_job.wait_sync()
 
-        command = f"/bin/cp -a {shlex.quote(home_old) + '/' + '.'} {shlex.quote(home_new + '/')}"
-        do_copy = await run(["/usr/bin/su", "-", username, "-c", command], check=False)
-        if do_copy.returncode != 0:
-            raise CallError(f"Failed to copy homedir [{home_old}] to [{home_new}]: {do_copy.stderr.decode()}")
+        return asdict(copytree(home_old, home_new, CopyTreeConfig(exist_ok=True, job=job)))
 
     @private
     async def common_validation(self, verrors, data, schema, group_ids, old=None):

src/middlewared/middlewared/plugins/filesystem.py

@@ -21,7 +21,7 @@
 from middlewared.utils.filesystem.acl import acl_is_present
 from middlewared.utils.filesystem.constants import FileType
 from middlewared.utils.filesystem.directory import DirectoryIterator, DirectoryRequestMask
-from middlewared.utils.filesystem.utils import timespec_convert
+from middlewared.utils.filesystem.utils import timespec_convert_float
 from middlewared.utils.mount import getmntinfo
 from middlewared.utils.nss import pwd, grp
 from middlewared.utils.path import FSLocation, path_location, is_child_realpath
@@ -454,10 +454,10 @@ def stat(self, _path):
             'mode': st['st'].stx_mode,
             'uid': st['st'].stx_uid,
             'gid': st['st'].stx_gid,
-            'atime': timespec_convert(st['st'].stx_atime),
-            'mtime': timespec_convert(st['st'].stx_mtime),
-            'ctime': timespec_convert(st['st'].stx_ctime),
-            'btime': timespec_convert(st['st'].stx_btime),
+            'atime': timespec_convert_float(st['st'].stx_atime),
+            'mtime': timespec_convert_float(st['st'].stx_mtime),
+            'ctime': timespec_convert_float(st['st'].stx_ctime),
+            'btime': timespec_convert_float(st['st'].stx_btime),
             'mount_id': st['st'].stx_mnt_id,
             'dev': os.makedev(st['st'].stx_dev_major, st['st'].stx_dev_minor),
             'inode': st['st'].stx_ino,