From ceded5a24a1bde2c9d9d731464e29675e8af3210 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sun, 26 Jun 2022 23:19:43 -0600
Subject: optimize

---
 cmd/btrfs-fsck/pass1.go | 53 +++++++++++++++++++++++++++++++------------------
 1 file changed, 34 insertions(+), 19 deletions(-)

(limited to 'cmd/btrfs-fsck')

diff --git a/cmd/btrfs-fsck/pass1.go b/cmd/btrfs-fsck/pass1.go
index 32d9456..a83697f 100644
--- a/cmd/btrfs-fsck/pass1.go
+++ b/cmd/btrfs-fsck/pass1.go
@@ -90,30 +90,13 @@ func (found pass1ScanOneDevResult) AddToLV(fs *btrfs.FS, dev *btrfs.Device) {
 	printProgress := func() {
 		pct := int(100 * float64(done) / float64(total))
 		if pct != lastProgress || done == total {
-			fmt.Printf("Pass 1: ... added %v%% of the mappings (%v/%v)\n",
-				pct, done, total)
+			fmt.Printf("Pass 1: ... added %v%% of the mappings (%v/%v=>%v)\n",
+				pct, done, total, len(fs.LV.Mappings()))
 			lastProgress = pct
 		}
 	}
 	printProgress()
 
-	for laddr, paddrs := range found.FoundNodes {
-		for _, paddr := range paddrs {
-			if err := fs.LV.AddMapping(btrfsvol.Mapping{
-				LAddr: laddr,
-				PAddr: btrfsvol.QualifiedPhysicalAddr{
-					Dev:  sb.Data.DevItem.DevID,
-					Addr: paddr,
-				},
-				Size:  btrfsvol.AddrDelta(sb.Data.NodeSize),
-				Flags: nil,
-			}); err != nil {
-				fmt.Printf("Pass 1: ... error: adding node ident: %v\n", err)
-			}
-			done++
-			printProgress()
-		}
-	}
 	for _, chunk := range found.FoundChunks {
 		for _, mapping := range chunk.Chunk.Mappings(chunk.Key) {
 			if err := fs.LV.AddMapping(mapping); err != nil {
@@ -123,6 +106,7 @@ func (found pass1ScanOneDevResult) AddToLV(fs *btrfs.FS, dev *btrfs.Device) {
 			printProgress()
 		}
 	}
+
 	for _, ext := range found.FoundDevExtents {
 		if err := fs.LV.AddMapping(ext.DevExt.Mapping(ext.Key)); err != nil {
 			fmt.Printf("Pass 1: ... error: adding devext: %v\n", err)
@@ -130,6 +114,37 @@ func (found pass1ScanOneDevResult) AddToLV(fs *btrfs.FS, dev *btrfs.Device) {
 		done++
 		printProgress()
 	}
+
+	// Do the nodes last to avoid bloating the mappings table too
+	// much.
+	//
+	// Sort them so that progress numbers are predictable.
+	laddrs := make([]btrfsvol.LogicalAddr, 0, len(found.FoundNodes))
+	for laddr := range found.FoundNodes {
+		laddrs = append(laddrs, laddr)
+	}
+	sort.Slice(laddrs, func(i, j int) bool {
+		// And sort them in reverse order to keep insertions
+		// fast.
+		return laddrs[i] > laddrs[j]
+	})
+	for _, laddr := range laddrs {
+		for _, paddr := range found.FoundNodes[laddr] {
+			if err := fs.LV.AddMapping(btrfsvol.Mapping{
+				LAddr: laddr,
+				PAddr: btrfsvol.QualifiedPhysicalAddr{
+					Dev:  sb.Data.DevItem.DevID,
+					Addr: paddr,
+				},
+				Size:  btrfsvol.AddrDelta(sb.Data.NodeSize),
+				Flags: nil,
+			}); err != nil {
+				fmt.Printf("Pass 1: ... error: adding node ident: %v\n", err)
+			}
+			done++
+			printProgress()
+		}
+	}
 }
 
 func pass1ScanOneDev(dev *btrfs.Device, superblock btrfs.Superblock) (pass1ScanOneDevResult, error) {
-- 
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