* fix(tier): preserve volume data modification time
* fix(tier): best-effort restore of data mtime on download
A failed Chtimes should not abort an otherwise complete tier-down; warn
and continue, matching the EC copy path.
* fix(tier): preserve volume data mtime in rust volume server
Mirror the Go fix: store the source .dat mtime on upload instead of the
upload time, and restore it on the downloaded .dat. Without this a
tiered-then-restored volume loads last_modified_ts_seconds from the
upload/download time, extending its TTL across a restart or remount.
* fix(tier): read source mtime via DiskFile.GetStat()
GetStat() is nil-safe when the backend is closed concurrently and skips a
redundant stat syscall; its cached modTime is the on-disk mtime a reload
reads, since every .dat write or Chtimes is followed by a DiskFile (re)open.
* fix(tier): surface mtime-restore failures on rust tier-down
set_file_mtime now returns io::Result; the tier-down path warns on a
failed restore instead of dropping it silently, so a wrong local .dat
mtime (and the TTL drift it causes) is observable. Matches the Go
download. The EC copy path keeps its best-effort silence.
Chris LuandGitHub
aabd44fbb5