Step 5 foundation of docs/plan/derived-blobs.md. Creates the mapping
table for server-derived artifacts and registers it as a blob-reference
source — deliberately BEFORE anything writes to it, which is the
ordering the plan requires: dedup_gc's reap predicate has to know the
table exists, or the first sweep after the first thumbnail deletes it.
No writer yet, so this is inert: the table is empty and every added SQL
term counts zero. The point is that the machinery is in place first.
storage.content_derived_blobs maps (source_hash, kind, variant) to the
derived blob_hash. The two hash columns mean different things and the
migration says so at length: source_hash is a DEPENDENT pointer holding
no reference (the file keeps the source alive), while blob_hash is a
reference HOLDER bumping chunk_manifests.ref_count. Counting source_hash
would pin every source Blob for as long as a thumbnail existed.
ContentDerivedReferenceSource contributes at the manifest level only.
A derived artifact's blob_hash names a Blob, never a chunk, and
contributing at the chunk level would double-count — a thumbnail is
almost always single-chunk, so its manifest hash equals its lone chunk's
hash, the same aliasing trap the legacy-files term guards against with
NOT EXISTS. There is a test for the invariant, and the chunk-level
golden test passing UNCHANGED is independent confirmation.
Collapses three definitions of "what references a blob" into one.
Adding the source revealed that DI assembled its own registry while
DedupService::new built a different default, and the two consistency
test helpers built a third — so the golden tests would have pinned SQL
production never runs. There is now a single `built_in_registry(pool)`;
DI reads it back via DedupService::reference_registry() rather than
assembling its own.
The reap-predicate golden test caught the change exactly as designed,
and the new branch landed inside the NOT (...) group ORed with files —
so a manifest is reaped only when NEITHER source references it. A branch
landing outside that group would have inverted the predicate for every
other source; that is why the test pins the whole statement rather than
asserting substrings.
fmt, clippy --all-features --all-targets, and 15 unit tests clean.
fix(migrations): order content_derived_blobs after the refcount fixes
Renames 20261015000000_content_derived_blobs.sql to
20261018000000_content_derived_blobs.sql.
The file was authored before the rebase onto fix/copy_folder_ref_count_issue,
so its version sorted BEFORE migrations that now precede it in history:
20261016000000_copy_folder_tree_manifest_refcount.sql
20261017000000_file_delete_trigger_manifest_aware.sql
20261017000002_repair_existing_refcount_drift.sql
Filename order and commit order disagreeing is the problem, not any
dependency — the table is standalone and creates nothing those
migrations touch. But an installation that has already applied through
…17000002 would then be offered a LOWER unapplied version, which sqlx
either applies out of order or rejects on its version check, and a
fresh install would get an ordering no upgrade path ever produces.
Reproducibility between the two is the whole point of the version
prefix.
Kept as its own commit rather than amending 01d90524, since interactive
rebase isn't available here and rewriting mid-branch while the ref_count
work is still being rebased elsewhere would churn hashes again. Worth
squashing into 01d90524 at merge.
No content change — pure rename, verified nothing references the old
filename.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
execute once via SQL migration to fix old entries
next: will be catch by manifests_consistency job, if new are found it means new bug discovered
no auto repair to prevent hidding bugs, operator can still invoke repair while waiting a fix
Silent data loss on an ordinary UI folder copy.
The function bumped only storage.blobs:
UPDATE storage.blobs b SET ref_count = ref_count + hc.cnt
FROM (...) hc WHERE b.hash = hc.blob_hash;
but a CDC file's blob_hash names a MANIFEST, not a chunk. For any
multi-chunk file that predicate matches zero rows, so the copy took no
reference at all. Delete the original afterwards and remove_reference
walks the manifest to 0, dedup_gc reaps the manifest and every chunk
behind it, and the copy is unreadable.
Single-chunk files escaped by accident: their whole-file hash equals
their lone chunk's hash, so the UPDATE did match — bumping the wrong
counter, which surfaces as a manifest under-count plus a blob
over-count rather than as loss. That asymmetry is why the bug survived:
small files, which dominate most test corpora, look fine.
Reproduced through the UI on a 5 MiB / 18-chunk file:
chunk_manifests.ref_count stayed at 1 while two storage.files rows
referenced it, and manifests_consistency reported
manifest_refcount_mismatch with delta 1, reap_risk true.
The fix mirrors DedupService::add_reference — manifest first, blobs only
as fallback, with a NOT EXISTS guard so a single-chunk file is not
counted at both levels (which would turn the under-count into an
over-count). orphaned_at is cleared on the blobs branch, as
add_reference does when resurrecting a blob inside its GC grace window.
Only the reference-counting block changes; the rest of the function is
20260902000001 verbatim.
Existing drift is deliberately NOT repaired here — a schema migration
cannot know which counter is authoritative. manifests_consistency
reports it; repair belongs with the recovery framework.
NOT executed against a database: the test instance was down and the dev
instance is read-only by convention. A parse error would fail at boot,
before any data is touched. Verify by re-running the reproduction — a
folder copy of a >1 MiB file should now leave ref_count at 2.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
OPAQUE (RFC 9807) implementation (using `opaque-ke` crate)
with opaque authentfication, server will never receive the password (in the auth=password mode)
this is a must have to create trust with users to permit end to end encryption in the future
(we cannot know if user use the same password/passphrase for his asymetric key or his oxicloud auth,
this is why server must never have the password)
pass1: prepare server
Resolve conflicts between the external-file-mounts feature and upstream's
D5/D7 refactor (per-file provenance, keyset pagination, cross-drive move
gates, resource-access hook, folder-cascade lifecycle hook).
Key resolutions:
- FolderService::new now takes (repo, authz, file_lifecycle, mount_router);
all callers + DI updated.
- FileRetrievalService / FileManagementService keep both the mount_router
and the new resource_access_hook / drive_repo / storage_usage wiring.
- list_files_batch_with_perms: adapt the mount branch from offset- to
keyset (after_name) pagination, mirroring paginate_mount_entries.
- download_file_impl: keep upstream's &HeaderMap + `impl IntoResponse + use<>`
signature, retain the mount-download branch.
- Mount DTOs: the retired `owner_id` field maps onto created_by/updated_by
(the mount owner) — the fields the frontend now uses for owner display.
- admin/+page.svelte: keep upstream's user-delete modal + the 'mounts' tab.
- Bump memmap2 0.9.10 -> 0.9.11 (RUSTSEC critical advisory fix) and
regenerate Cargo.lock against the merged Cargo.toml.
Benchmark-gated round (benches/ROUND12.md; every change ships with a
BEFORE/AFTER harness + equivalence gates, one candidate rejected by its
own bench):
DB / query shapes (bench_round12_queries):
- NC sharee search: username-only projection instead of the 21-column row
(incl. the <=512 KiB avatar) per match, + gin_trgm_ops indexes on
auth.users for the leading-wildcard ILIKE (4.98x; 54.7x with index).
- Password login: delete the redundant full-row update_user — create_session
already stamps last_login_at in its own txn (4.45x per login).
- Email-verified stamp: narrow conditional UPDATE (8.9x); OIDC repeat login
now compares profile state in memory and issues ZERO queries when nothing
changed (was: full 17-column rewrite per login).
- Refresh rotation: revoke+insert+stamp fused into one transaction via new
rotate_session port method (1.18x).
- WOPI CheckFileInfo / authorize_wopi_access: require(Read) + get_file +
check(Update) overlapped with tokio::join!, original result precedence
(cold 1.34x).
- Upload quota gate: user-envelope + drive-cap checks fused into ONE
round-trip (check_upload_quotas) — the NC chunked PUT pays this per
chunk (1.81x, 2 -> 1 queries/chunk); shared verdict evaluators keep
error shapes byte-identical.
CPU / allocs (bench_round12_micro):
- sized_json: pre-sized listing serialization replacing axum Json's 128 B
seed + doubling-realloc chain on files/folder-resources/photos/search
responses (1.40x, 13 -> 2 allocs per 500-row page; byte-identical).
- Security headers: 4 SetResponseHeaderLayer folded into the CSP middleware
pass (5 layers -> 1; 1.43x per request, -26 allocs; header set gated
byte-identical incl. 304s).
- Media capture-metadata: single-read extraction — nom-exif now parses the
buffer kamadak already read (zero-copy Bytes) and videos open once with a
kind() dispatch; per-image opens 2-3 -> 1 (1.44x warm geomean, 1.6-3.2x
cold cache; extraction outputs gated identical incl. the MIME-mislabel
track fallback).
- Chunked-upload session ops: owner gate folded into the operation's own
DashMap lookup + stack-encoded uuid compare (5 -> 3 lookups, -2 allocs,
1.28x per chunk).
Blob cache (bench_blob_cache_index + round-3 regression guard):
- CachedBlobBackend index: tokio::sync::Mutex<LruCache> -> moka::sync::Cache
with byte weigher. The mutex serialized every cached chunk read and scaled
NEGATIVELY (2.08 -> 1.07 Mops/s from 1 -> 2 readers); moka probes are
lock-free (2.17x at K=2). Byte budget now enforced by moka (manual
current_size + collect_evictions machinery deleted); eviction listener
unlinks size-evicted files only (Replaced entries keep their file —
gated). Single-flight miss gate unchanged (16 concurrent misses -> 1
fetch re-verified via the round-3 harness).
- put_blob now populates the cache BEFORE the inner backend consumes the
source file (the old order failed 100% of the time — local renames,
S3/Azure delete the source — so the first read after a whole-file put
re-downloaded from the remote); inner-put failure invalidates the entry.
Frontend (vitest gates):
- List-view thumbnails request the 150px icon rendition instead of 400px
preview into a 40px slot (~7.1x fewer pixels, ~4-5x fewer bytes per
thumbnail across list views); grid keeps preview.
Rejected by its own bench (kept as evidence in bench_round12_micro §2):
- Single-pass compression predicate: the monomorphized And-chain already
costs ~4.6 ns / 0 allocs total; the fused node measured within noise.
New migration: 20260719000000_users_search_trgm.sql (trgm indexes).
Deferred with prepared design: grouped file/grid view virtualization
(single-VirtualRows flatten, the photos pattern) — next round's headline.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BfidAJD5AHw23jtvBUNamB
Round 3 of benchmark-gated optimizations (benches/ROUND3.md; every change
gated by a before/after benchmark — an AFTER that did not beat its BEFORE
was to be rolled back; none needed it. Equivalence gates assert identical
row sequences / byte-identical output on every behavior-preserving rewrite):
DB hot paths (local PG16, EXPLAIN-verified):
- Web-UI listing (list_resources_paged): cursor pushed INSIDE the
folders/files UNION-ALL branches as sargable row-value comparisons with
per-branch ORDER/LIMIT + two partial expression indexes
(folder_id, LOWER(name), id). 20k-entry folder: 26.6 -> 1.3 ms/page
(19.5x); other sort modes at parity or better. New migration
20260918000000. [benches/LISTING-KEYSET.md section in ROUND3]
- Photos timeline (list_media_files): per-drive CROSS JOIN LATERAL top-N
on the timeline index, joins moved above the top-N. 50k-photo library:
97.4 -> 1.6 ms/page (55.7x). The old "LIMIT stops the scan early"
comment was refuted by EXPLAIN.
- PROPFIND sub-folders (both DAV surfaces): keyset list_folders_batch off
idx_folders_unique_name replaces COUNT(*) OVER() + LIMIT/OFFSET
(5k dirs: 79.7 -> 17.9 ms full walk, 4.5x).
Concurrency:
- Basic-auth cache single-flight (moka try_get_with): 8 concurrent DAV
connections at TTL expiry paid 8 Argon2id runs (2.6 s CPU + 8x64 MiB);
now 1 (300 ms). Failed verifications remain uncached.
- CachedBlobBackend per-hash single-flight + unique tmp names: 16
concurrent cold readers = 16 full remote downloads racing truncating
writes on ONE deterministic .tmp (corruptible cache); now 1 download
(16x less egress, 2.8x wall on a shared link) and torn files can never
be renamed into the cache.
I/O and allocations:
- Chunk-assembly reads 64K -> 512K buffers (2.3x, 8x fewer syscalls);
chunk-spool writes via BufWriter 512K (5.6x, 32x fewer syscalls).
- S3/Azure put_blob_from_bytes_unsynced overrides: dedup settle no longer
pays a HEAD probe per new chunk (2 RTT -> 1, 1.8x); Azure stops copying
every chunk (Bytes -> Body, -0.44 ms - 4 MiB alloc per 4 MiB chunk).
- Entity->DTO mapping: Arc<str> interning of closed-set display fields +
common MIMEs, 1-alloc etag/size formatting, FolderDto moves instead of
clones. File row: 11 -> 4 allocs; folder row: 11.8 -> 1 (2.1x faster).
- CardDAV REPORT: deleted dead per-contact vCard pre-generation and the
O(N^2) uid scan whose result was discarded (5k contacts: 55.7 -> 5.7 ms,
9.8x); byte-identical XML asserted.
- Search-results cache: byte weigher + 32 MiB budget
(OXICLOUD_SEARCH_CACHE_MAX_BYTES) replaces the 1000-ENTRY cap that let
~300 MiB of enriched rows sit in RSS; read latency parity.
- Dropped aws-config + aws-smithy-types (zero references; -82 dep-graph
nodes, three SDK stacks gone from every build). tokio "process" is now
an explicit feature (was enabled transitively by aws-config).
Frontend:
- Cached Intl.DateTimeFormat keyed by (locale, options) in formatDate and
4 sibling callsites: 20k dates 2612 -> 51 ms (51.6x); vitest gate
asserts output identity across locales and a 3x floor.
Validation: cargo fmt + clippy --all-features --all-targets -D warnings
clean; 518 unit + 548 integration-cfg tests green; new-shape endpoints
smoke-tested end-to-end over HTTP (all 5 listing sort modes with cursor
walks, WebDAV PROPFIND Depth-1, photos timeline, Basic-auth DAV login);
frontend npm run check clean, new vitest gates green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EBsU2qEzny3A8WQUEuMNCr
Every change is benchmark-verified (harness + before/after numbers in
benches/, measured on this branch; reproduction commands in each doc):
DAV / sync-client hot paths
- PROPFIND dead-properties: one = ANY($1) query per 500-child page instead
of one sequential query per child, and indexable `=` predicates instead
of IS NOT DISTINCT FROM (seq scans). 2,000-child folder: 1.07-4.54 s of
DB chatter -> 4-6 ms (258-773x). Applied to native + NC PROPFIND and
both NC REPORT handlers. [benches/DEAD-PROPS.md]
- Folder paging: keyset cursor (name > $last) + new partial index
(folder_id, name) replaces LIMIT/OFFSET full-folder rescan per page.
Full 20k-file walk: 1266 ms -> 77 ms (16.5x). New migration
20260917000000. [benches/PROPFIND-PAGING.md]
- NC chroot / default-drive resolution: moka caches (30 s TTL, explicit
invalidation on drive mutations) for find_default_for_user and the
markerless chroot FolderDto. 2 uncached queries + 2 pool checkouts per
NC/WebDAV/WOPI request -> sub-us moka hit (p50 0.7-3.6 ms -> ~1 us).
[benches/CHROOT-CACHE.md]
- Quota: PROPFINDs whose prop list never names a quota prop skip the
2-query resolution entirely (wants_quota()); the remaining lookups read
2 columns instead of the full auth.users row with its <=512 KiB avatar
(11-16x, p50 3.4 ms -> 0.29 ms). Same narrow read now gates every
upload quota check. [benches/QUOTA-PATH.md]
CPU on the request path
- ZIP exports (folder download, share ZIP, batch download): entries whose
MIME says already-compressed (JPEG/MP4/zip/pdf/...) are Stored instead
of Deflate - deflate ran inline on the tokio writer task at ~41 MB/s
for ~0% size gain. Mixed media corpus: 4.31x wall and CPU, archive size
unchanged. Shared predicate in common::mime_detect. [benches/ZIP-MEDIA.md]
- Compression layers: tower-http's default maps to Brotli QUALITY 11
(verified in brotli-8.0.2 source and empirically: 90 ms per 64 KiB JSON
response, 1.3 s per 700 KiB bundle). Both layers pinned to Precise(4):
99x less CPU for ~15% more bytes. SPA assets are now precompressed at
build time (scripts/precompress.mjs, 77% smaller) and served via
ServeDir::precompressed_br/gzip: 2016x less per-request work, and
clients get the better q11 bytes. [benches/STATIC-PRECOMPRESSED.md]
Batched / cached backend paths [benches/NPLUS1-AND-CACHES.md]
- Content-search ReBAC re-verification: new
AuthorizationEngine::check_files_read_batch (default = old loop;
PgAclEngine override batches drive resolution + reuses role cache).
200 sequential point SELECTs per search -> 1-2 queries.
- Batch-ZIP subtree downloads: drop per-file re-authz + per-file Recent
recording (2 writes/file) for subtree entries already authorized at the
root - mirrors the native folder-download path. ~6,000 statements
removed from a 2,000-file archive.
- CDC chunk manifests: immutable by content address, now moka-cached
(weight-bounded 32 MiB, 60 s TTL, positive-only, invalidated on delete)
- removes one manifest query (p50 0.44-4.4 ms) from every stream,
range and full blob read.
- People tab: grouped COUNT + batched cover lookup instead of dragging
every face row with its 2 KiB embedding (10k faces: 30.4 ms & 21 MB ->
3.8 ms & 1.3 KB, 8.1x); merge() is one set-based UPDATE.
[benches/PEOPLE-LIST.md]
- Photos timeline cursor: raw timestamptz comparison instead of
EXTRACT(EPOCH ...) wrapper + IS NULL OR disjunction - cursor is an
index boundary again, deep scroll stops re-scanning skipped rows.
- Public share landing: one atomic UPDATE ... access_count + 1 (was
SELECT + full-row write-back: racy, lost updates, clobbered concurrent
owner edits) - 3 round-trips -> 2 per visit.
- move_to_trash: dead full-entity SELECT feeding a documented no-op
removed from both branches; dead fields dropped from TrashService.
- NFC normalization: is_nfc_quick fast path skips the decompose/recompose
state machine for the ~100% already-NFC case (every row loaded from PG).
Frontend
- Large folders paint after page one (~200 items) via fetchFolderListing's
new onPage hook instead of waiting for every sequential page.
- Tested-and-reverted (kept for the record): cached Intl.Collator for name
sorts - vitest showed it 2x SLOWER than V8's argument-less localeCompare
fast path (5.6 ms vs 12.1 ms / 5k names). Sort order untouched.
New bench harnesses under examples/ (bench feature): zip_media,
dead_props, chroot_cache, quota_path, people_list, propfind_paging,
static_precompress.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBK1RdtzyP6759Muqe1K1w
- add resource kind filter (file, folder, drive) in shared section (localStorage stored)
- add user preferences serverside store
- add client side dotfile filter (show/hide dotfiles) (user perf stored, default: dotfiles are shown)
for security trashed dotfile are always displayed
protection added: if a folder has only hidden items, a notification invite user to display it
if a user rename or create a hidden item, a notification tells it to user
plan:
```
What step 5 is actually doing
Goal: stop writing to storage.files.user_id / storage.folders.user_id on new INSERTs. This is a prerequisite for step 6 (dropping the column entirely). The column has existed since the pre-D0 single-owner era; every read that used to key on it has already been migrated to drive-membership grants over the last N days.
What has to change together for this to be safe:
┌──────────────┬─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ Piece │ What changes │ Why │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Migration │ Swap storage.files uniqueness indexes from (folder_id, name, user_id) to (drive_id, folder_id, name) │ Otherwise, two new rows with user_id = NULL would both be allowed (PG treats NULLs as distinct) — │
│ (a) │ │ uniqueness silently breaks │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Migration │ ALTER user_id DROP NOT NULL on both tables │ Otherwise, dropping the INSERT bind violates NOT NULL and every write 500s │
│ (b) │ │ │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Migration │ Drop dead user_id-leading indexes │ Cheap cleanup — nothing scans them anymore │
│ (c) │ │ │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ PL/pgSQL (d) │ Rewrite storage.copy_folder_tree without user_id in the INSERT column list │ Cross-drive copy runs entirely in SQL, needs the same treatment │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Rust (e) │ ~12 INSERT column-list drops across folder_db_repository, file_blob_write_repository, drive_pg_repository, dedup_service, │ Actual write path │
│ │ folder_service, load-seed.rs │ │
├──────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Rust (f) │ Simplify folder_db_repository::create_folder's parent lookup to only fetch drive_id (was fetching (user_id, drive_id)) │ It's fetching a value it no longer needs │
└──────────────┴─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────┘
```
add `include_in_photo_index` and `include_in_music_index` policies
both true for default personal drive
photo is implemented
music is not yet implemented
Adds the foundation for external file mounts: admin-configured backends
(raw host filesystem in v1; sftp/webdav/… as future provider kinds) surfaced
as a folder inside a user's drive. Mount contents are virtual/live-passthrough
— read straight from the backend, never stored in storage.files — and are a
deliberately separate, limited storage type (no dedup/sharing/trash/search).
The feature is dark by default (OXICLOUD_ENABLE_EXTERNAL_MOUNTS=false).
P1 scope (this PR): data model, the pluggable provider abstraction, and the
read-only REST surface (mount listing + download). Read-write (P2),
WebDAV/NextCloud path resolution (P3), and the admin UI (P4) follow.
Core model
- Mount root = a real storage.folders row; authorization for everything inside
collapses onto that folder UUID (ltree-ancestry grant cascade).
- Children are virtual, addressed by ext:<mount_id>:<base64url(node_id)> where
node_id is provider-owned and opaque to the rest of the system.
- A lock-free (arc-swap) MountRegistry maps mount-root UUID -> provider; a thin
MountRouter::classify() is the single cheap hook handlers call before parsing
an id as a UUID. With no mounts configured it always returns Regular, so
existing code paths are unchanged.
Added
- migrations/20260805000000_external_mounts.sql (storage.external_mounts, kind + config JSONB)
- domain/services/external_mount_id (id envelope + virtual etags)
- application/ports/external_mount_ports (ExternalMountProvider, MountProviderFactory, repo port)
- infrastructure local_fs_mount_provider (tokio::fs, symlink-escape-safe) + factory
- application MountRegistry + MountRouter, pg ExternalMountRepository
- DI wiring (AppState.mount_router), FeaturesConfig.enable_external_mounts
- listing branch (FolderService::list_mount_dir_with_perms + folder_handler) and
download branch (FileRetrievalService stat/open mount methods + file_handler)
Authorization stays in the service layer (authz.require(Resource::Folder(mount_id)));
handlers only classify. Cross-backend operations are out of scope for P1.
Tests: 529 unit tests + 5 testcontainers integration tests (real Postgres 17),
including end-to-end authorization (owner allowed, stranger denied). Line
coverage of the new modules is 84–100% (cargo-llvm-cov). Known gap:
file_handler::download_mount_file (HTTP glue) needs a full-app test (P4).
now Drive is purely a metadata
each drive has always a root folder
this model minimize Oxicloud changes, and simplify
the Drive name is simply the folder's root's name
note: owner of Drive has more permission that an owner of the root folder
Edouard Vanbelle