* extend cache-not-ready handling to filer HTTP path
Mirror the s3api change for the native filer HTTP handlers. When the
filer GET hits a remote-only object whose cache fill hasn't completed,
return 503 Service Unavailable with Retry-After: 5 instead of 500
Internal Error, and treat client disconnects as silent cancellations
rather than logging them as errors.
Adds an ErrCacheNotReady sentinel and a small helper used at the
prepareWriteFn-error sites in ProcessRangeRequest, so the same
classification (cancel / not-ready / other) applies to plain GETs,
single-range, and multi-range requests.
* clear Content-Range on prepareWriteFn error
The single-range path sets Content-Range before calling prepareWriteFn.
If prepareWriteFn fails, http.Error is about to write a fresh body for
503 or 500, but the stale Content-Range header would still go out and
no longer match. Drop it alongside Content-Length in the shared helper
so all current and future callers are covered.
* strip success-path headers and forward NotFound on prepareWriteFn error
When ProcessRangeRequest writes an error response, the previously-set
success headers (Content-Disposition, ETag, Last-Modified, in addition
to Content-Length/Content-Range) shouldn't ride along on the new body.
With ?dl=1 a stale Content-Disposition would even cause browsers to
save the error message under the object's filename. Strip them all in
the shared helper.
Also forward filer_pb.ErrNotFound through the cache-failure branch so a
mid-cache entry deletion surfaces as 404, not as a 503 retry-loop.
Permanent upstream cloud errors (403/404 from the cloud SDK) still come
back as opaque wrapped strings via FetchAndWriteNeedle and remain
mapped to 503; distinguishing those would need a wider refactor.
Chris LuandGitHub
7f770b1553