diff --git a/copyparty/up2k.py b/copyparty/up2k.py
index 707060d7..df1a61df 100644
--- a/copyparty/up2k.py
+++ b/copyparty/up2k.py
@@ -12,6 +12,7 @@ import shutil
 import signal
 import stat
 import subprocess as sp
+import tempfile
 import threading
 import time
 import traceback
@@ -71,6 +72,8 @@ class Dbw(object):
 
 
 class Mpqe(object):
+    """pending files to tag-scan"""
+
     def __init__(
         self,
         mtp: dict[str, MParser],
@@ -129,6 +132,8 @@ class Up2k(object):
         self.mem_cur = None
         self.sqlite_ver = None
         self.no_expr_idx = False
+        self.timeout = int(max(self.args.srch_time, 5) * 1.2)
+        self.spools: set[tempfile.SpooledTemporaryFile[bytes]] = set()
         if HAVE_SQLITE3:
             # mojibake detector
             self.mem_cur = self._orz(":memory:")
@@ -201,8 +206,9 @@ class Up2k(object):
         self.log("uploads temporarily blocked due to " + why, 3)
 
     def _unblock(self) -> None:
-        self.blocked = None
-        self.log("uploads are now possible", 2)
+        if self.blocked is not None:
+            self.blocked = None
+            self.log("uploads are now possible", 2)
 
     def get_state(self) -> str:
         mtpq: Union[int, str] = 0
@@ -458,10 +464,9 @@ class Up2k(object):
 
             self.volstate[vol.vpath] = t
 
-        # file contents verification
-        if next((zv for zv in vols if "e2v" in zv.flags), None):
-            self._block("integrity verification")
+        self._unblock()
 
+        # file contents verification
         for vol in vols:
             if self.stop:
                 break
@@ -485,9 +490,6 @@ class Up2k(object):
 
             self.volstate[vol.vpath] = t
 
-        if self.blocked:
-            self._unblock()
-
         # open the rest + do any e2ts(a)
         needed_mutagen = False
         for vol in vols:
@@ -665,7 +667,7 @@ class Up2k(object):
             n_add = n_rm = 0
             try:
                 n_add = self._build_dir(db, top, set(excl), top, rtop, rei, reh, [])
-                n_rm = self._drop_lost(db.c, top)
+                n_rm = self._drop_lost(db.c, top, excl)
             except Exception as ex:
                 db_ex_chk(self.log, ex, db_path)
                 t = "failed to index volume [{}]:\n{}"
@@ -698,6 +700,7 @@ class Up2k(object):
         assert self.pp and self.mem_cur
         self.pp.msg = "a{} {}".format(self.pp.n, cdir)
         ret = 0
+        unreg: list[str] = []
         seen_files = {}  # != inames; files-only for dropcheck
         g = statdir(self.log_func, not self.args.no_scandir, False, cdir)
         gl = sorted(g)
@@ -707,7 +710,12 @@ class Up2k(object):
                 return -1
 
             abspath = os.path.join(cdir, iname)
+            rp = abspath[len(top) :].lstrip("/")
+            if WINDOWS:
+                rp = rp.replace("\\", "/").strip("/")
+
             if rei and rei.search(abspath):
+                unreg.append(rp)
                 continue
 
             nohash = reh.search(abspath) if reh else False
@@ -716,6 +724,7 @@ class Up2k(object):
             if stat.S_ISDIR(inf.st_mode):
                 rap = absreal(abspath)
                 if abspath in excl or rap in excl:
+                    unreg.append(rp)
                     continue
                 if iname == ".th" and bos.path.isdir(os.path.join(abspath, "top")):
                     # abandoned or foreign, skip
@@ -731,10 +740,6 @@ class Up2k(object):
             else:
                 # self.log("file: {}".format(abspath))
                 seen_files[iname] = 1
-                rp = abspath[len(top) :].lstrip("/")
-                if WINDOWS:
-                    rp = rp.replace("\\", "/").strip("/")
-
                 if rp.endswith(".PARTIAL") and time.time() - lmod < 60:
                     # rescan during upload
                     continue
@@ -806,6 +811,25 @@ class Up2k(object):
         if self.stop:
             return -1
 
+        # drop shadowed folders
+        for rd in unreg:
+            n = 0
+            q = "select count(w) from up where (rd = ? or rd like ?||'%') and at == 0"
+            for erd in [rd, "//" + w8b64enc(rd)]:
+                try:
+                    n = db.c.execute(q, (erd, erd + "/")).fetchone()[0]
+                    break
+                except:
+                    pass
+
+            if n:
+                t = "forgetting {} shadowed autoindexed files in [{}] > [{}]"
+                self.log(t.format(n, top, rd))
+
+                q = "delete from up where (rd = ? or rd like ?||'%') and at == 0"
+                db.c.execute(q, (erd, erd + "/"))
+                ret += n
+
         # drop missing files
         rd = cdir[len(top) + 1 :].strip("/")
         if WINDOWS:
@@ -828,12 +852,13 @@ class Up2k(object):
 
         return ret
 
-    def _drop_lost(self, cur: "sqlite3.Cursor", top: str) -> int:
+    def _drop_lost(self, cur: "sqlite3.Cursor", top: str, excl: list[str]) -> int:
         rm = []
         n_rm = 0
         nchecked = 0
         assert self.pp
-        # `_build_dir` did all the files, now do dirs
+
+        # `_build_dir` did all unshadowed files; first do dirs:
         ndirs = next(cur.execute("select count(distinct rd) from up"))[0]
         c = cur.execute("select distinct rd from up order by rd desc")
         for (drd,) in c:
@@ -853,18 +878,50 @@ class Up2k(object):
 
             rm.append(drd)
 
-        if not rm:
-            return 0
+        if rm:
+            q = "select count(w) from up where rd = ?"
+            for rd in rm:
+                n_rm += next(cur.execute(q, (rd,)))[0]
 
-        q = "select count(w) from up where rd = ?"
-        for rd in rm:
-            n_rm += next(cur.execute(q, (rd,)))[0]
+            self.log("forgetting {} deleted dirs, {} files".format(len(rm), n_rm))
+            for rd in rm:
+                cur.execute("delete from up where rd = ?", (rd,))
 
-        self.log("forgetting {} deleted dirs, {} files".format(len(rm), n_rm))
-        for rd in rm:
-            cur.execute("delete from up where rd = ?", (rd,))
+        # then shadowed deleted files
+        n_rm2 = 0
+        c2 = cur.connection.cursor()
+        excl = [x[len(top) + 1 :] for x in excl if x.startswith(top + "/")]
+        q = "select rd, fn from up where (rd = ? or rd like ?||'%') order by rd"
+        for rd in excl:
+            for erd in [rd, "//" + w8b64enc(rd)]:
+                try:
+                    c = cur.execute(q, (erd, erd + "/"))
+                    break
+                except:
+                    pass
 
-        return n_rm
+            crd = "///"
+            cdc: set[str] = set()
+            for drd, dfn in c:
+                rd, fn = s3dec(drd, dfn)
+
+                if crd != rd:
+                    crd = rd
+                    try:
+                        cdc = set(os.listdir(os.path.join(top, rd)))
+                    except:
+                        cdc.clear()
+
+                if fn not in cdc:
+                    q = "delete from up where rd = ? and fn = ?"
+                    c2.execute(q, (drd, dfn))
+                    n_rm2 += 1
+
+        if n_rm2:
+            self.log("forgetting {} shadowed deleted files".format(n_rm2))
+
+        c2.close()
+        return n_rm + n_rm2
 
     def _verify_integrity(self, vol: VFS) -> int:
         """expensive; blocks database access until finished"""
@@ -888,7 +945,7 @@ class Up2k(object):
             qexa.append("up.rd != ? and not up.rd like ?||'%'")
             pexa.extend([vpath, vpath])
 
-        pex = tuple(pexa)
+        pex: tuple[Any, ...] = tuple(pexa)
         qex = " and ".join(qexa)
         if qex:
             qex = " where " + qex
@@ -903,11 +960,22 @@ class Up2k(object):
                 b_left += sz  # sum() can overflow according to docs
                 n_left += 1
 
-            q = "select w, mt, sz, rd, fn from up" + qex
-            for w, mt, sz, drd, dfn in cur.execute(q, pex):
+            tf, _ = self._spool_warks(cur, "select w, rd, fn from up" + qex, pex, 0)
+
+        with gzip.GzipFile(mode="rb", fileobj=tf) as gf:
+            for zb in gf:
                 if self.stop:
                     return -1
 
+                w, drd, dfn = zb[:-1].decode("utf-8").split("\x00")
+                with self.mutex:
+                    q = "select mt, sz from up where w = ? and rd = ? and fn = ?"
+                    try:
+                        mt, sz = cur.execute(q, (w, drd, dfn)).fetchone()
+                    except:
+                        # file moved/deleted since spooling
+                        continue
+
                 n_left -= 1
                 b_left -= sz
                 if drd.startswith("//") or dfn.startswith("//"):
@@ -952,18 +1020,21 @@ class Up2k(object):
                 t = t.format(abspath, w, sz, mt, w2, sz2, mt2)
                 self.log(t, 1)
 
-            if e2vp and rewark:
-                self.hub.retcode = 1
-                os.kill(os.getpid(), signal.SIGTERM)
-                raise Exception("{} files have incorrect hashes".format(len(rewark)))
+        if e2vp and rewark:
+            self.hub.retcode = 1
+            os.kill(os.getpid(), signal.SIGTERM)
+            raise Exception("{} files have incorrect hashes".format(len(rewark)))
 
-            if not e2vu:
-                return 0
+        if not e2vu or not rewark:
+            return 0
 
+        with self.mutex:
             for rd, fn, w, sz, mt in rewark:
                 q = "update up set w = ?, sz = ?, mt = ? where rd = ? and fn = ? limit 1"
                 cur.execute(q, (w, sz, int(mt), rd, fn))
 
+            cur.connection.commit()
+
         return len(rewark)
 
     def _build_tags_index(self, vol: VFS) -> tuple[int, int, bool]:
@@ -977,11 +1048,7 @@ class Up2k(object):
         flags = self.flags[ptop]
         cur = self.cur[ptop]
 
-        n_add = 0
         n_rm = 0
-        n_buf = 0
-        last_write = time.time()
-
         if "e2tsr" in flags:
             with self.mutex:
                 n_rm = cur.execute("select count(w) from mt").fetchone()[0]
@@ -992,93 +1059,153 @@ class Up2k(object):
         # integrity: drop tags for tracks that were deleted
         if "e2t" in flags:
             with self.mutex:
-                drops = []
+                n = 0
                 c2 = cur.connection.cursor()
                 up_q = "select w from up where substr(w,1,16) = ?"
+                rm_q = "delete from mt where w = ?"
                 for (w,) in cur.execute("select w from mt"):
                     if not c2.execute(up_q, (w,)).fetchone():
-                        drops.append(w[:16])
-                c2.close()
+                        c2.execute(rm_q, (w[:16],))
+                        n += 1
 
-                if drops:
-                    msg = "discarding media tags for {} deleted files"
-                    self.log(msg.format(len(drops)))
-                    n_rm += len(drops)
-                    for w in drops:
-                        cur.execute("delete from mt where w = ?", (w,))
+                c2.close()
+                if n:
+                    t = "discarded media tags for {} deleted files"
+                    self.log(t.format(n))
+                    n_rm += n
+
+        with self.mutex:
+            cur.connection.commit()
 
         # bail if a volume flag disables indexing
         if "d2t" in flags or "d2d" in flags:
-            return n_add, n_rm, True
+            return 0, n_rm, True
 
         # add tags for new files
-        gcur = cur
-        with self.mutex:
-            gcur.connection.commit()
-
         if "e2ts" in flags:
             if not self.mtag:
-                return n_add, n_rm, False
+                return 0, n_rm, False
 
-            mpool: Optional[Queue[Mpqe]] = None
+            nq = 0
+            with self.mutex:
+                tf, nq = self._spool_warks(
+                    cur, "select w from up order by rd, fn", (), 1
+                )
 
-            if self.mtag.prefer_mt and self.args.mtag_mt > 1:
-                mpool = self._start_mpool()
+            if not nq:
+                # self.log("tags ok")
+                self._unspool(tf)
+                return 0, n_rm, True
 
-            # TODO blocks writes to registry cursor; do chunks instead
-            conn = sqlite3.connect(db_path, timeout=15)
-            cur = conn.cursor()
-            c2 = conn.cursor()
-            c3 = conn.cursor()
-            n_left = cur.execute("select count(w) from up").fetchone()[0]
-            for w, rd, fn in cur.execute("select w, rd, fn from up order by rd, fn"):
-                if self.stop:
-                    return -1, -1, False
+            if nq == -1:
+                return -1, -1, True
 
-                n_left -= 1
-                q = "select w from mt where w = ?"
-                if c2.execute(q, (w[:16],)).fetchone():
-                    continue
+            with gzip.GzipFile(mode="rb", fileobj=tf) as gf:
+                n_add = self._e2ts_q(gf, nq, cur, ptop, entags)
 
-                if "mtp" in flags:
-                    q = "insert into mt values (?,'t:mtp','a')"
-                    c2.execute(q, (w[:16],))
-
-                if rd.startswith("//") or fn.startswith("//"):
-                    rd, fn = s3dec(rd, fn)
-
-                abspath = os.path.join(ptop, rd, fn)
-                self.pp.msg = "c{} {}".format(n_left, abspath)
-                if not mpool:
-                    n_tags = self._tag_file(c3, entags, w, abspath)
-                else:
-                    mpool.put(Mpqe({}, entags, w, abspath, {}))
-                    # not registry cursor; do not self.mutex:
-                    n_tags = len(self._flush_mpool(c3))
-
-                n_add += n_tags
-                n_buf += n_tags
-
-                td = time.time() - last_write
-                if n_buf >= 4096 or td >= 60:
-                    self.log("commit {} new tags".format(n_buf))
-                    cur.connection.commit()
-                    last_write = time.time()
-                    n_buf = 0
-
-            if mpool:
-                self._stop_mpool(mpool)
-                with self.mutex:
-                    n_add += len(self._flush_mpool(c3))
-
-            conn.commit()
-            c3.close()
-            c2.close()
-            cur.close()
-            conn.close()
+            self._unspool(tf)
 
         return n_add, n_rm, True
 
+    def _e2ts_q(
+        self,
+        qf: gzip.GzipFile,
+        nq: int,
+        cur: "sqlite3.Cursor",
+        ptop: str,
+        entags: set[str],
+    ) -> int:
+        assert self.pp and self.mtag
+
+        mpool: Optional[Queue[Mpqe]] = None
+        if self.mtag.prefer_mt and self.args.mtag_mt > 1:
+            mpool = self._start_mpool()
+
+        n_add = 0
+        n_buf = 0
+        last_write = time.time()
+        for bw in qf:
+            if self.stop:
+                return -1
+
+            w = bw[:-1].decode("ascii")
+
+            q = "select rd, fn from up where w = ?"
+            try:
+                rd, fn = cur.execute(q, (w,)).fetchone()
+            except:
+                # file modified/deleted since spooling
+                continue
+
+            if rd.startswith("//") or fn.startswith("//"):
+                rd, fn = s3dec(rd, fn)
+
+            abspath = os.path.join(ptop, rd, fn)
+            self.pp.msg = "c{} {}".format(nq, abspath)
+            if not mpool:
+                n_tags = self._tagscan_file(cur, entags, w, abspath)
+            else:
+                mpool.put(Mpqe({}, entags, w, abspath, {}))
+                with self.mutex:
+                    n_tags = len(self._flush_mpool(cur))
+
+            n_add += n_tags
+            n_buf += n_tags
+
+            td = time.time() - last_write
+            if n_buf >= 4096 or td >= max(1, self.timeout - 1):
+                self.log("commit {} new tags".format(n_buf))
+                with self.mutex:
+                    cur.connection.commit()
+
+                last_write = time.time()
+                n_buf = 0
+
+        if mpool:
+            self._stop_mpool(mpool)
+            with self.mutex:
+                n_add += len(self._flush_mpool(cur))
+
+        with self.mutex:
+            cur.connection.commit()
+
+        return n_add
+
+    def _spool_warks(
+        self,
+        cur: "sqlite3.Cursor",
+        q: str,
+        params: tuple[Any, ...],
+        flt: int,
+    ) -> tuple[tempfile.SpooledTemporaryFile[bytes], int]:
+        n = 0
+        c2 = cur.connection.cursor()
+        tf = tempfile.SpooledTemporaryFile(1024 * 1024 * 8, "w+b", prefix="cpp-tq-")
+        with gzip.GzipFile(mode="wb", fileobj=tf) as gf:
+            for row in cur.execute(q, params):
+                if self.stop:
+                    return tf, -1
+
+                if flt == 1:
+                    q = "select w from mt where w = ?"
+                    if c2.execute(q, (row[0][:16],)).fetchone():
+                        continue
+
+                gf.write("{}\n".format("\x00".join(row)).encode("utf-8"))
+                n += 1
+
+        c2.close()
+        tf.seek(0)
+        self.spools.add(tf)
+        return tf, n
+
+    def _unspool(self, tf: tempfile.SpooledTemporaryFile[bytes]) -> None:
+        self.spools.remove(tf)
+        try:
+            tf.close()
+        except Exception as ex:
+            self.log("failed to delete spool: {}".format(ex), 3)
+
     def _flush_mpool(self, wcur: "sqlite3.Cursor") -> list[str]:
         ret = []
         for x in self.pending_tags:
@@ -1338,21 +1465,38 @@ class Up2k(object):
         msg = "{} failed to read tags from {}:\n{}".format(parser, abspath, ex)
         self.log(msg.lstrip(), c=1 if "<Signals.SIG" in msg else 3)
 
+    def _tagscan_file(
+        self,
+        write_cur: "sqlite3.Cursor",
+        entags: set[str],
+        wark: str,
+        abspath: str,
+    ) -> int:
+        """will mutex"""
+        assert self.mtag
+
+        if not bos.path.isfile(abspath):
+            return 0
+
+        try:
+            tags = self.mtag.get(abspath)
+        except Exception as ex:
+            self._log_tag_err("", abspath, ex)
+            return 0
+
+        with self.mutex:
+            return self._tag_file(write_cur, entags, wark, abspath, tags)
+
     def _tag_file(
         self,
         write_cur: "sqlite3.Cursor",
         entags: set[str],
         wark: str,
         abspath: str,
-        tags: Optional[dict[str, Union[str, float]]] = None,
+        tags: dict[str, Union[str, float]],
     ) -> int:
+        """mutex me"""
         assert self.mtag
-        if tags is None:
-            try:
-                tags = self.mtag.get(abspath)
-            except Exception as ex:
-                self._log_tag_err("", abspath, ex)
-                return 0
 
         if not bos.path.isfile(abspath):
             return 0
@@ -1382,8 +1526,7 @@ class Up2k(object):
         return ret
 
     def _orz(self, db_path: str) -> "sqlite3.Cursor":
-        timeout = int(max(self.args.srch_time, 5) * 1.2)
-        return sqlite3.connect(db_path, timeout, check_same_thread=False).cursor()
+        return sqlite3.connect(db_path, self.timeout, check_same_thread=False).cursor()
         # x.set_trace_callback(trace)
 
     def _open_db(self, db_path: str) -> "sqlite3.Cursor":
@@ -1953,7 +2096,9 @@ class Up2k(object):
             self.db_add(cur, wark, rd, fn, lmod, sz, ip, at)
             cur.connection.commit()
         except Exception as ex:
-            db_ex_chk(self.log, ex, self.register_vpath(ptop, {})[1])
+            x = self.register_vpath(ptop, {})
+            assert x
+            db_ex_chk(self.log, ex, x[1])
             raise
 
         if "e2t" in self.flags[ptop]:
@@ -2657,6 +2802,10 @@ class Up2k(object):
 
     def shutdown(self) -> None:
         self.stop = True
+
+        for x in list(self.spools):
+            self._unspool(x)
+
         self.log("writing snapshot")
         self.do_snapshot()
 
diff --git a/copyparty/util.py b/copyparty/util.py
index 0a758067..477166f0 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -1196,15 +1196,10 @@ def s3enc(mem_cur: "sqlite3.Cursor", rd: str, fn: str) -> tuple[str, str]:
 
 
 def s3dec(rd: str, fn: str) -> tuple[str, str]:
-    ret = []
-    for v in [rd, fn]:
-        if v.startswith("//"):
-            ret.append(w8b64dec(v[2:]))
-            # self.log("mojide [{}] {}".format(ret[-1], v[2:]))
-        else:
-            ret.append(v)
-
-    return ret[0], ret[1]
+    return (
+        w8b64dec(rd[2:]) if rd.startswith("//") else rd,
+        w8b64dec(fn[2:]) if fn.startswith("//") else fn,
+    )
 
 
 def db_ex_chk(log: "NamedLogger", ex: Exception, db_path: str) -> None: