Self-review of this branch caught a data-loss bug I introduced with the
per-app / group files ceilings: the quota check ran AFTER the blob write.
`write_atomic_at` renames the new bytes over the FINAL path, so by the time
the ceiling refused an update the previous bytes were already gone. The
per-app path then unlinked the blob (row survives, file destroyed — every
read 404s); the group path left the new bytes in place under the old row's
checksum (every read fails `Corrupted`). Either way a user permanently lost
a file merely by exceeding a quota — a strictly worse outcome than the
unchecked-update bypass the ceiling was added to close.
The check now precedes the write on create AND update, per-app and group. As
a bonus this stops an over-quota caller driving unbounded write+unlink disk
churn: the ceiling now bounds I/O, not just stored bytes. The blob still goes
down inside the transaction, under the advisory lock, so a rollback unlinks
it and nothing can reference it in between.
The original test passed against the bug: it asserted the refused update did
not change the stored byte TOTAL — true, while the blob was already
destroyed. The regression test now reads the file back through the
checksum-verifying `FsFilesRepo::get`, and was confirmed to fail with
`Corrupted` against the old ordering.
Also in the KV writer (same file): drop the redundant pre-read on the hottest
write path. `set`/`set_if` did a SELECT purely to learn whether the write
would add a row, when the upsert already returns the previous value. Check
after the insert instead (`>` not `>=`) and let the transaction roll back on
refusal — identical outcome, one round-trip fewer, and an update pays nothing
at all. `kv_repo::get_on` and `FsFilesRepo::final_path` are now unused and
deleted; `FilesRepo::delete` delegates to the `delete_meta_on` + `unlink_blob`
helpers rather than re-implementing them.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
An app's OWN store had no ceiling of any kind — only the group-SHARED
collections did, which is the inversion of what you'd expect. And
`authz::script_gate` returns `Ok(())` when there is no principal, so a
PUBLIC UNAUTHENTICATED route could reach `files::collection(..).create(..)`
and write blobs in a loop until the disk filled. `PICLOUD_FILES_MAX_FILE_SIZE_BYTES`
caps ONE file at 100 MB; nothing capped the count. Same for KV keys and docs
against Postgres.
Ceilings: `PICLOUD_APP_KV_MAX_ROWS` / `PICLOUD_APP_DOCS_MAX_ROWS` (100k) and
`PICLOUD_APP_FILES_MAX_TOTAL_BYTES` (10 GiB).
They are enforced DIFFERENTLY from the group ones, on purpose — porting the
group design as-is would have been a serious regression:
* KV/docs check a ROW count, on INSERT only, with NO lock. `kv::set` is the
hottest write path in the system; taking a per-app advisory lock on every
set would serialize an app's entire data plane, and a `SUM(...)` scan would
make write cost grow with the app's stored size. What the lock buys is
small — unlocked overshoot is bounded by write concurrency (32) against a
ceiling of 100k, ~0.03%. These are anti-DoS rails, not billing. An update
adds no row and is bounded by the per-value cap, so it pays nothing at all.
* No per-app BYTE ceiling for KV/docs: every value is already capped at
`PICLOUD_KV_MAX_VALUE_BYTES`, so `max_rows x max_value_bytes` is ALREADY a
finite bound. A second scan would buy nothing.
* FILES are the exception and DO lock + sum: one blob may be 100 MB, so 32
racing uploads could overshoot by gigabytes of real disk, and a file write
is heavy enough that the lock and the SUM are lost in the noise. Checked on
create AND update — an update that skipped the ceiling would be a free
bypass (the same bug just fixed for group files: grow a 1-byte file to
100 MB, repeat).
`group_quota` is renamed `quota`: it now serves both owners, and the module
doc is where the two enforcement strategies are contrasted.
Pinned by tests/atomic_write.rs: the key ceiling refuses a new key while
still allowing an update at the ceiling (rejecting updates would brick an app
the moment it filled up — worse than the DoS the rail exists to stop), and 10
concurrent uploads cannot exceed the disk ceiling, nor can an update grow past it.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Audit #6 and #8 for the last of the three stores, plus a bypass found on
the way.
**#6.** create/update/delete wrote the metadata row, then emitted
best-effort, so an outbox failure left a committed file whose trigger never
fired. `atomic_write::FilesWriter` commits the metadata row and the fan-out
together.
Files are the one store where the ordering is subtle, because the BYTES live
on disk and cannot join a transaction:
* create/update — blob first, then commit metadata + fan-out. A rollback
unlinks the blob. (A crash at that exact point still orphans it; that
hazard predates this change — the repo already wrote the blob and then
inserted the row in a separate, failable statement — and the orphan is
inert, referenced by nothing.)
* delete — commit the metadata removal + fan-out FIRST, then unlink. The
reverse order would destroy the bytes of a row that a rollback keeps,
leaving a file that can never be read.
**#8.** `GroupFilesService::create` read `total_bytes` on one connection and
wrote on another, so concurrent uploads each saw the same pre-write total and
together overshot the ceiling. This is the worst instance of the race in the
codebase: the ceiling is DISK (10 GiB by default) and one file may be 100 MB,
so a racing fleet overshoots by gigabytes. `PostgresGroupFilesWriter` takes
the per-group advisory lock (on its own `files` key) across the check and the
write.
**The bypass.** `GroupFilesService::update` checked NO quota at all — so a
1-byte file could be updated to a 100 MB one without the ceiling ever being
consulted, repeatedly, for unbounded disk. It now checks the projected total
(the replaced file's bytes subtracted in SQL, so a same-size-or-smaller
update near the cap still goes through).
Also drive-by: `queue_e2e` asserted the ack the instant the marker appeared,
but the marker is written DURING the handler and the ack happens after it
returns — a zero-tolerance race. It polls now. (This does not fix the
suite's flakiness, which reproduces on the pre-pass commit too.)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Extends the §11.6 shared-collection machinery to the filesystem-backed
`files` blob store (after KV/0053 and docs/0054).
- 0055_group_files.sql: widen the group_collections kind CHECK to admit
'files'; add a group-keyed `group_files` metadata table mirroring
`files` (0018), CASCADE on group delete.
- files_repo: generalize the four path/IO free functions
(shard_dir_at / final_path_at / write_atomic_at / read_verify_at) to
take an owner-relative dir instead of `app_id`, and make them (plus the
cursor helpers) pub(crate). The security-sensitive atomic-write +
checksum-on-read mechanics now have a single source shared by the app
and group repos. App behavior is unchanged (apps shard at `<app_id>/`).
- group_files_repo: FsGroupFilesRepo keyed by group_id, blobs at
`<root>/files/groups/<group_id>/<collection>/<id[0:2]>/<id>` — a
`groups/` infix disjoint from the per-app subtree, so the existing
recursive orphan sweeper covers it with zero change.
Schema snapshot blessed (55 migrations); app-files fs tests still green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The admin files endpoints hit FsFilesRepo directly (not via
FilesServiceImpl, which validates), so only create/update guarded the
collection — head/get/list/delete built FS paths from an unvalidated
value. Today nothing can store a traversal-shaped collection, but one
future bad migration / restore tool inserting collection='../../etc'
would give the read/delete paths arbitrary host-file reach.
- FsFilesRepo::{head,get,list,delete} now call guard_collection (create
and update already did).
- The three admin endpoints (list/get/delete) call
validate_files_collection up front for a clean 422 instead of the
repo guard surfacing as an opaque 500.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Filesystem-backed blob storage as the fifth concrete trigger kind.
- `files::collection(c).{create,head,get,update,delete,list}` Rhai SDK
(blob in/out; metadata maps; missing-field throws naming the field).
- `FilesService` trait in picloud-shared; `FsFilesRepo` (atomic
write: temp→fsync→rename→fsync-dir→DB; single-pass SHA-256;
checksum-verified reads → Corrupted) + `FilesServiceImpl` in
manager-core. Metadata in Postgres (0018), bytes on disk under
PICLOUD_FILES_ROOT with 0o700 shard dirs.
- `files:*` trigger kind via the Layout-E pattern (0019: widen both
CHECKs + files_trigger_details), TriggerEvent::Files (metadata only,
no bytes), emit_files fan-out, dispatcher arm, admin endpoint
POST /triggers/files (reuses validate_trigger_target).
- AppFilesRead/AppFilesWrite capabilities → script:read/script:write
(seven-scope commitment held). AppPubsubPublish reserved for v1.1.6.
- Admin files API (list + delete) + dashboard Files view per app.
Cross-app isolation keyed on cx.app_id at every layer. ~45 new tests
(service in-memory, fs tempdir, bridge integration). No DB required
for the suite. publish_ephemeral and the orphan sweep stay deferred.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
