cached diskIDs are not needed for scanner healing (#14170)

This PR removes an unnecessary state that gets
passed around for DiskIDs, which is not necessary
since each disk exactly knows which pool and which
set it belongs to on a running system.

Currently cached DiskId's won't work properly
because it always ends up skipping offline disks
and never runs healing when disks are offline, as
it expects all the cached diskIDs to be present
always. This also sort of made things in-flexible
in terms perhaps a new diskID for `format.json`.
(however this is not a big issue)

This is an unnecessary requirement that healing
via scanner needs all drives to be online, instead
healing should trigger even when partial nodes
and drives are available this ensures that we
keep the SLA in-tact on the objects when disks
are offline for a prolonged period of time.

cmd/data-scanner.go

@@ -22,6 +22,7 @@ import (
 	"context"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io/fs"
 	"math"
 	"math/rand"
@@ -33,6 +34,7 @@ import (
 	"time"
 
 	"github.com/bits-and-blooms/bloom/v3"
+	"github.com/dustin/go-humanize"
 	"github.com/minio/madmin-go"
 	"github.com/minio/minio/internal/bucket/lifecycle"
 	"github.com/minio/minio/internal/bucket/replication"
@@ -181,7 +183,8 @@ type folderScanner struct {
 	healFolderInclude     uint32 // Include a clean folder one in n cycles.
 	healObjectSelect      uint32 // Do a heal check on an object once every n cycles. Must divide into healFolderInclude
 
-	disks []StorageAPI
+	disks       []StorageAPI
+	disksQuorum int
 
 	// If set updates will be sent regularly to this channel.
 	// Will not be closed when returned.
@@ -247,7 +250,7 @@ var globalScannerStats scannerStats
 // The returned cache will always be valid, but may not be updated from the existing.
 // Before each operation sleepDuration is called which can be used to temporarily halt the scanner.
 // If the supplied context is canceled the function will return at the first chance.
-func scanDataFolder(ctx context.Context, basePath string, cache dataUsageCache, getSize getSizeFn) (dataUsageCache, error) {
+func scanDataFolder(ctx context.Context, poolIdx, setIdx int, basePath string, cache dataUsageCache, getSize getSizeFn) (dataUsageCache, error) {
 	t := UTCNow()
 
 	logPrefix := color.Green("data-usage: ")
@@ -280,13 +283,15 @@ func scanDataFolder(ctx context.Context, basePath string, cache dataUsageCache,
 	}
 
 	// Add disks for set healing.
-	if len(cache.Disks) > 0 {
+	if poolIdx >= 0 && setIdx >= 0 {
 		objAPI, ok := newObjectLayerFn().(*erasureServerPools)
 		if ok {
-			s.disks = objAPI.GetDisksID(cache.Disks...)
-			if len(s.disks) != len(cache.Disks) {
-				console.Debugf(logPrefix+"Missing disks, want %d, found %d. Cannot heal. %s\n", len(cache.Disks), len(s.disks), logSuffix)
-				s.disks = s.disks[:0]
+			if poolIdx < len(objAPI.serverPools) && setIdx < len(objAPI.serverPools[poolIdx].sets) {
+				// Pass the disks belonging to the set.
+				s.disks = objAPI.serverPools[poolIdx].sets[setIdx].getDisks()
+				s.disksQuorum = objAPI.serverPools[poolIdx].sets[setIdx].defaultRQuorum()
+			} else {
+				logger.LogIf(ctx, fmt.Errorf("Matching pool %s, set %s not found", humanize.Ordinal(poolIdx+1), humanize.Ordinal(setIdx+1)))
 			}
 		}
 	}
@@ -623,7 +628,7 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 		}
 
 		objAPI, ok := newObjectLayerFn().(*erasureServerPools)
-		if !ok || len(f.disks) == 0 {
+		if !ok || len(f.disks) == 0 || f.disksQuorum == 0 {
 			break
 		}
 
@@ -645,8 +650,8 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 		// This means that the next run will not look for it.
 		// How to resolve results.
 		resolver := metadataResolutionParams{
-			dirQuorum: getReadQuorum(len(f.disks)),
-			objQuorum: getReadQuorum(len(f.disks)),
+			dirQuorum: f.disksQuorum,
+			objQuorum: f.disksQuorum,
 			bucket:    "",
 			strict:    false,
 		}
@@ -676,8 +681,7 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 				path:           prefix,
 				recursive:      true,
 				reportNotFound: true,
-				minDisks:       len(f.disks), // We want full consistency.
-				// Weird, maybe transient error.
+				minDisks:       f.disksQuorum,
 				agreed: func(entry metaCacheEntry) {
 					if f.dataUsageScannerDebug {
 						console.Debugf(healObjectsPrefix+" got agreement: %v\n", entry.name)