package writecache import ( "context" "errors" "fmt" "os" "time" "git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs" "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common" "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard/mode" "git.frostfs.info/TrueCloudLab/frostfs-observability/tracing" "go.opentelemetry.io/otel/attribute" "go.opentelemetry.io/otel/trace" ) type setModePrm struct { ignoreErrors bool shrink bool } // SetMode sets write-cache mode of operation. // When shard is put in read-only mode all objects in memory are flushed to disk // and all background jobs are suspended. func (c *cache) SetMode(m mode.Mode) error { ctx, span := tracing.StartSpanFromContext(context.TODO(), "writecache.SetMode", trace.WithAttributes( attribute.String("mode", m.String()), )) defer span.End() c.modeMtx.Lock() defer c.modeMtx.Unlock() err := c.setMode(ctx, m, setModePrm{ignoreErrors: true}) if err == nil { c.metrics.SetMode(mode.ConvertToComponentModeDegraded(m)) } return err } // setMode applies new mode. Must be called with cache.modeMtx lock taken. func (c *cache) setMode(ctx context.Context, m mode.Mode, prm setModePrm) error { var err error turnOffMeta := m.NoMetabase() if turnOffMeta && !c.mode.NoMetabase() { err = c.flush(ctx, prm.ignoreErrors) if err != nil { return err } } if err := c.closeStorage(ctx, prm.shrink); err != nil { return err } // Suspend producers to ensure there are channel send operations in fly. // flushCh is populated by `flush` with `modeMtx` taken, thus waiting until it is empty // guarantees that there are no in-fly operations. for len(c.flushCh) != 0 { c.log.Info(logs.WritecacheWaitingForChannelsToFlush) time.Sleep(time.Second) } if turnOffMeta { c.mode = m return nil } if err = c.openStore(mode.ConvertToComponentModeDegraded(m)); err != nil { return err } c.mode = m return nil } func (c *cache) closeStorage(ctx context.Context, shrink bool) error { if c.fsTree == nil { return nil } if !shrink { if err := c.fsTree.Close(); err != nil { return fmt.Errorf("can't close write-cache storage: %w", err) } return nil } empty := true _, err := c.fsTree.Iterate(ctx, common.IteratePrm{ Handler: func(common.IterationElement) error { return errIterationCompleted }, }) if err != nil { if errors.Is(err, errIterationCompleted) { empty = false } else { return fmt.Errorf("failed to check write-cache items: %w", err) } } if err := c.fsTree.Close(); err != nil { return fmt.Errorf("can't close write-cache storage: %w", err) } if empty { err := os.RemoveAll(c.path) if err != nil && !os.IsNotExist(err) { return fmt.Errorf("failed to remove write-cache files: %w", err) } } else { c.log.Info(logs.WritecacheShrinkSkippedNotEmpty) } return nil } // readOnly returns true if current mode is read-only. // `c.modeMtx` must be taken. func (c *cache) readOnly() bool { return c.mode.ReadOnly() } // noMetabase returns true if c is operating without the metabase. // `c.modeMtx` must be taken. func (c *cache) noMetabase() bool { return c.mode.NoMetabase() }