never call FSHC with nil mountpath; reduce code

* also, remove erroneous assert

Signed-off-by: Alex Aizman <[email protected]>

ais/target.go

@@ -762,7 +762,6 @@ func (t *target) getObject(w http.ResponseWriter, r *http.Request, dpq *dpq, bck
 	// do
 	if ecode, err := goi.getObject(); err != nil {
 		if !goi.isIOErr {
-			debug.Assert(err != errSendingResp && !cos.IsRetriableConnErr(err), err)
 			t.statsT.IncNonIOErr()
 		}
 

ais/tgtfshc.go

@@ -5,8 +5,6 @@
 package ais
 
 import (
-	"fmt"
-
 	"github.com/NVIDIA/aistore/cmn"
 	"github.com/NVIDIA/aistore/cmn/cos"
 	"github.com/NVIDIA/aistore/cmn/debug"
@@ -23,50 +21,37 @@ func (t *target) SoftFSHC() {
 }
 
 func (t *target) FSHC(err error, mi *fs.Mountpath, fqn string) {
-	config := cmn.GCO.Get()
+	debug.Assert(mi != nil)
 
+	config := cmn.GCO.Get()
 	if cmn.IsErrCapExceeded(err) {
 		cs := t.oos(config)
-		nlog.Errorf("%s: OOS (%s) via FSHC", t, cs.String())
+		nlog.Errorf("%s: OOS (%s) via FSHC, %s", t, cs.String(), mi)
 		return
 	}
 
 	if !config.FSHC.Enabled {
 		return
 	}
+
+	// NOTE: filter-out non-IO errors
 	if !t.fshc.IsErr(err) {
 		if cmn.Rom.FastV(4, cos.SmoduleAIS) {
 			nlog.Warningln(err, "is not one of the error types to trigger FSHC, ignoring...")
 		}
 		return
 	}
 
-	s := fmt.Sprintf("waking up FSHC to check %s, err: %v", mi, err) // or maybe not (waking up)
-
-	if mi == nil {
-		mi, _, err = fs.FQN2Mpath(fqn)
-		if err != nil {
-			if e, ok := err.(*cmn.ErrMpathNotFound); ok {
-				if e.Disabled() {
-					nlog.Errorf("%s: %s is disabled, not %s", t, e.Mpath(), s)
-					return
-				}
-			}
-			nlog.Errorf("%s: %v, %s", t, err, s)
-			return
-		}
-		debug.Assert(mi != nil)
-	}
 	if !mi.IsAvail() {
-		nlog.Warningln(mi.String(), "is not available, skipping FSHC")
+		nlog.Warningln(mi.String(), "is not available (possibly disabled or detached), skipping FSHC")
 		return
 	}
 
-	// yes "waking up"
-	nlog.Errorln(t.String()+":", s)
+	nlog.Errorf("%s: waking up FSHC to check %s, err: %v", t, mi, err)
 
 	//
-	// metrics: counting I/O errors on a per mountpath (`NameSuffix` below) basis
+	// counting I/O errors on a per mountpath
+	// TODO -- FIXME: remove `NameSuffix`
 	//
 	t.statsT.AddMany(cos.NamedVal64{Name: stats.ErrIOCount, NameSuffix: mi.Path, Value: 1})
 	t.fshc.OnErr(mi, fqn)

ais/tgtobj.go

@@ -1163,13 +1163,12 @@ func (goi *getOI) transmit(r io.Reader, buf []byte, fqn string) error {
 	written, err := cos.CopyBuffer(goi.w, r, buf)
 	if err != nil {
 		if !cos.IsRetriableConnErr(err) {
-			mi := goi.lom.Mountpath()
-			if fqn != goi.lom.FQN {
-				mi = nil
-			}
-			goi.t.FSHC(err, mi, fqn)
+			nlog.Errorln("failed to GET", goi.lom.String()+":", err)
+			goi.t.FSHC(err, goi.lom.Mountpath(), fqn)
+		} else if cmn.Rom.FastV(4, cos.SmoduleAIS) {
+			nlog.Warningln("failed to GET", goi.lom.String()+":", err)
 		}
-		nlog.Errorln(cmn.NewErrFailedTo(goi.t, "GET", fqn, err))
+
 		// at this point, error is already written into the response -
 		// return special code to indicate just that
 		return errSendingResp

core/lcopy.go

@@ -156,7 +156,12 @@ func (lom *LOM) syncMetaWithCopies() (err error) {
 		}
 		lom.delCopyMd(copyFQN)
 		if err1 := cos.Stat(copyFQN); err1 != nil && !os.IsNotExist(err1) {
-			T.FSHC(err, nil, copyFQN) // TODO: notify scrubber
+			mi, _, err2 := fs.FQN2Mpath(copyFQN)
+			if err2 != nil {
+				nlog.Errorln("nested err:", err2, "fqn:", copyFQN)
+			} else {
+				T.FSHC(err, mi, copyFQN)
+			}
 		}
 	}
 	return