* admin: support setting volume read-only and read/write modes
* admin: address PR review on volume access-mode persistence
Reject trailing JSON values in the SetVolumeReadOnly handler so
requests like {"read_only":true}{} no longer pass validation, and add
a trailing-value case to the invalid-request test.
Propagate .vif persistence failures through the access-mode chain.
PersistReadOnly now returns the SaveVolumeInfo error and rolls back
the in-memory volumeInfo on failure; Store.MarkVolumeReadonly and
Store.MarkVolumeWritable propagate that error and roll back their
noWrite flags, so the API reports failure instead of success while
restart would revert the mode.
* admin: make .vif persistence atomic and preserve error chain
SaveVolumeInfo now writes to a .vif.tmp file, syncs it, renames it
over the target, and fsyncs the directory. A write/sync/close failure
leaves the existing .vif intact, so the PersistReadOnly in-memory
rollback matches the durable state instead of diverging from a
partially written file that restart would apply.
Switch the error wrappers in PersistReadOnly, MarkVolumeReadonly, and
MarkVolumeWritable from %v to %w so callers can use errors.Is and
errors.As to classify persistence failures.
* admin: treat post-rename dir fsync failure as a warning
After os.Rename commits the new .vif, the on-disk file already holds
the requested mode. A directory fsync failure only risks losing the
rename across a crash; returning an error here would make
PersistReadOnly roll back in-memory state while the durable file keeps
the new mode, splitting the replica. Log the failure as a warning
instead, matching the best-effort nature of FsyncDir (already skipped
on Windows).
* admin: distinguish post-rename durability failures and use unique temp files
SaveVolumeInfo now uses os.CreateTemp for the staging file, preventing
concurrent saves for the same volume from colliding on a shared .tmp
path.
A directory fsync failure after os.Rename returns a
NotCrashDurableError instead of being silently swallowed. The rename
already committed the new metadata to disk, so PersistReadOnly,
MarkVolumeReadonly, and MarkVolumeWritable skip the in-memory rollback
for this error type (keeping state aligned with the durable file) while
still propagating the failure to the API. Pre-commit failures continue
to roll back as before.
* admin: continue post-commit work after NotCrashDurableError
MarkVolumeWritable now clears the EIO quarantine and the gRPC handlers
(makeVolumeReadonly step 3, makeVolumeWritable master notification)
proceed with their post-commit work when SaveVolumeInfo returns a
NotCrashDurableError, instead of aborting and leaving the volume
unavailable or the master unaware of the mode change. The durability
warning is still propagated to the API caller. Pre-commit failures
continue to abort early as before.
* admin: handle NotCrashDurableError in tier and EC callers
VolumeTierMoveDatFromRemote and VolumeEcShardsGenerate now check for
NotCrashDurableError from SaveVolumeInfo. When the rename has already
committed the new .vif, they continue with their post-commit work
(backend switch, remote deletion, keeping generated EC shards) instead
of aborting and leaving the on-disk metadata inconsistent with the
file layout. The durability warning is logged for the operator.
A read-only or cloud-tiered volume loads a SortedFileNeedleMap, which held
both its .idx and its .sdx open for the life of the process. On a server with
~600K tiered volumes that is 1.2M descriptors before a single read, enough to
exhaust the fd limit and take the listeners down. The .dat is not the problem:
a tiered volume serves it from the remote backend.
Neither index file is needed except while a lookup is in flight, so borrow them
from a bounded process-wide pool instead. An idle volume now holds zero
descriptors; a busy one keeps its handles hot rather than paying an open() per
needle. Reads borrow O_RDONLY, so a volume on a read-only mount answers lookups
that previously failed at load. Sync tracks whether a tombstone was appended,
which also drops the fsync-per-volume storm at shutdown.