serve s3: HeadObject/GetObject return upload time as Last-Modified after PutObject #10128

What is the problem you are having with rclone?

After an object is uploaded with PutObject, HeadObject and GetObject return the upload time as Last-Modified instead of the object's modification time, until the metadata cache entry is evicted (by default only after 100000 newer objects or a restart). ListObjects returns the correct modification time, so a client sees two different times for the same object.

Cause: gofakes3 metadataHeaders() adds meta["Last-Modified"] = formatHeaderTime(now) to the request metadata. storeMeta() in cmd/serve/s3/backend.go stores that map in the metadata cache, and HeadObject/GetObject build meta with "Last-Modified": formatHeaderTime(node.ModTime()) and then maps.Copy(meta, metaMap), which overwrites it with the cached upload time. This happens even when X-Amz-Meta-Mtime set the object's modification time to something else.

Real-world effect: Remotely Save (Obsidian) records the Last-Modified from HeadObject right after an upload. When the user later deletes or renames that file on the device, the plugin compares the listing time with the recorded one, decides the remote file changed, and downloads it again instead of deleting it. Deletions of files uploaded from the device never take effect.

What is your rclone version (output from rclone version)

rclone v1.76.0-beta.10592.35a03a47e (docker image rclone/rclone:sha-35a03a4). The same happens with v1.75.1.

Which OS you are using and how many bits (e.g. Windows 7, 64 bit)

Linux amd64 (Docker, Alpine image), Ubuntu 24.04 host.

Which cloud storage system are you using? (e.g. Google Drive)

Google Drive behind a combine remote, served with rclone serve s3.

The command you were trying to run (e.g. rclone copy /tmp remote:tmp)

rclone serve s3 vault-combine: --addr :8080 --vfs-cache-mode writes --cache-dir /cache \
  --dir-cache-time 168h --poll-interval 15s --vfs-refresh

Reproduce with any S3 client:

touch -d "2021-06-06 06:06:06" leer.md
rclone copyto leer.md s3:bucket/leer.md
rclone lsl --use-server-modtime s3:bucket/leer.md                        # 2021-06-06 06:06:06 (correct, from ListObjects)
rclone lsl --use-server-modtime --dump headers s3:bucket/leer.md | grep -i last-modified
Last-Modified: Sun, 18 Oct 2026 18:52:20 GMT                             # upload time (wrong)

Suggested fix

Drop the gofakes3 upload time before caching:

func (t *tenant) storeMeta(_vfs *vfs.VFS, fp string, meta map[string]string) (err error) {
	delete(meta, "Last-Modified")
	...

With this change HeadObject/GetObject return the object's modification time right after the upload (tested against the same Google Drive backend: HEAD/GET right after PUT now return the X-Amz-Meta-Mtime time, deletes from the client propagate), and the Remotely Save delete/rename case works.

A log from the command with the -vv flag

Not needed; the behaviour is visible in the response headers above.

How to use GitHub

• Please use the 👍 reaction to show that you are affected by the same issue.