Space: the unit is a disk on its own or a ZFS pool as a whole, picked from a dropdown

A pool's member disks are listed under it, not offered apart; the picker shows the
layout, members, size and scan state.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/api/space.go

@@ -1,14 +1,15 @@
 package api
 
-// The Space tab: what is using a disk. A disk is picked, not a partition: the scan covers
+// The Space tab: what is using a disk or a pool. The unit is a whole volume, never a
-// every filesystem the disk backs — its partitions' mountpoints, and for a disk in a ZFS
+// partition: a disk on its own is scanned through every filesystem it backs, and a ZFS pool
-// pool, every mounted dataset of that pool (so any of the pool's disks shows the pool).
+// through every mounted dataset, as one thing — its member disks are not scanned apart.
 
 import (
 	"context"
 	"log"
 	"net/http"
 	"os/exec"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -18,51 +19,84 @@ import (
 	"hamlab/internal/storage"
 )
 
-type spaceDisk struct {
+// spaceTarget is one thing a scan can measure: a disk on its own, or a ZFS pool as a whole.
+// A disk that is a member of a pool is not a target of its own — its share of the pool means
+// nothing by itself — it is listed under the pool. (A disk with a pool partition *and* a
+// filesystem of its own, root on one partition and a pool on another, is both.)
+type spaceTarget struct {
+	ID     string      `json:"id"`   // "nvme0" or "pool:tank"
+	Kind   string      `json:"kind"` // disk | pool
 	Name   string      `json:"name"`
-	Kind  string      `json:"kind"`
+	Model  string      `json:"model,omitempty"`  // disk: its model
-	Model string      `json:"model,omitempty"`
+	Layout string      `json:"layout,omitempty"` // pool: raidz2, mirror, …
+	Health string      `json:"health,omitempty"` // pool: ONLINE, DEGRADED, …
 	Size   uint64      `json:"size"`
-	Pool  string      `json:"pool,omitempty"`  // the ZFS pool this disk is part of
+	Used   uint64      `json:"used,omitempty"` // pool: allocated
+	Disks  []string    `json:"disks,omitempty"` // pool: its member disks
 	Roots  []string    `json:"roots"`           // the mountpoints a scan walks
 	Scan   *space.Scan `json:"scan,omitempty"`  // the last scan, if any
 }
 
-// spaceDisks maps every disk to the mountpoints it backs.
+var layoutRe = regexp.MustCompile(`\b(draid\d*|raidz[123]?|mirror)\b`)
-func (s *Server) spaceDisks(ctx context.Context) []spaceDisk {
+
+// spaceTargets lists the disks and pools a scan can measure.
+func (s *Server) spaceTargets(ctx context.Context) []spaceTarget {
 	devs, _ := storage.Devices(ctx)
-	var out []spaceDisk
+	var out []spaceTarget
-	poolMounts := map[string][]string{}
+	pools := map[string]*spaceTarget{}
+	var poolOrder []string
 	for _, d := range devs {
-		sd := spaceDisk{Name: d.Name, Kind: d.Kind, Model: d.Model, Size: d.Size, Roots: []string{}}
+		disk := spaceTarget{ID: d.Name, Kind: "disk", Name: d.Name, Model: d.Model, Size: d.Size, Roots: []string{}}
 		seen := map[string]bool{}
+		inPool := false
 		for _, p := range d.Parts {
+			if p.FSType == "zfs_member" && p.Label != "" {
+				inPool = true
+				pt := pools[p.Label]
+				if pt == nil {
+					pt = &spaceTarget{ID: "pool:" + p.Label, Kind: "pool", Name: p.Label, Roots: zfsMounts(ctx, p.Label)}
+					if pt.Roots == nil {
+						pt.Roots = []string{}
+					}
+					pools[p.Label] = pt
+					poolOrder = append(poolOrder, p.Label)
+				}
+				pt.Disks = append(pt.Disks, d.Name)
+				continue
+			}
 			if p.Mount != "" && p.Mount != "[SWAP]" && !seen[p.Mount] {
 				seen[p.Mount] = true
-				sd.Roots = append(sd.Roots, p.Mount)
+				disk.Roots = append(disk.Roots, p.Mount)
-			}
-			if p.FSType == "zfs_member" && p.Label != "" && sd.Pool == "" {
-				sd.Pool = p.Label
 			}
 		}
-		if sd.Pool != "" {
+		if !inPool || len(disk.Roots) > 0 {
-			mounts, ok := poolMounts[sd.Pool]
+			sort.Strings(disk.Roots)
-			if !ok {
+			out = append(out, disk)
-				mounts = zfsMounts(ctx, sd.Pool)
-				poolMounts[sd.Pool] = mounts
 		}
-			for _, m := range mounts {
+	}
-				if !seen[m] {
+	if len(pools) > 0 {
-					seen[m] = true
+		// size, health and layout from zpool; the vdev tree names the layout
-					sd.Roots = append(sd.Roots, m)
+		for _, p := range s.storage.ZFS(ctx).Pools {
+			if pt := pools[p.Name]; pt != nil {
+				pt.Size, pt.Used, pt.Health = p.Size, p.Alloc, p.Health
+				if m := layoutRe.FindString(p.Config); m != "" {
+					pt.Layout = m
+				} else if len(pt.Disks) == 1 {
+					pt.Layout = "single disk"
+				} else if len(pt.Disks) > 1 {
+					pt.Layout = "stripe"
 				}
 			}
 		}
-		sort.Strings(sd.Roots)
+		var ps []spaceTarget
-		out = append(out, sd)
+		for _, name := range poolOrder {
+			sort.Strings(pools[name].Roots)
+			ps = append(ps, *pools[name])
+		}
+		out = append(ps, out...) // pools first: they are what a NAS is
 	}
 	if out == nil {
-		out = []spaceDisk{}
+		out = []spaceTarget{}
 	}
 	return out
 }
@@ -86,22 +120,22 @@ func zfsMounts(ctx context.Context, pool string) []string {
 }
 
 func (s *Server) spaceOverview(w http.ResponseWriter, r *http.Request) {
-	disks := s.spaceDisks(r.Context())
+	targets := s.spaceTargets(r.Context())
 	scans := s.space.All()
-	for i := range disks {
+	for i := range targets {
-		disks[i].Scan = scans[disks[i].Name]
+		targets[i].Scan = scans[targets[i].ID]
 	}
-	jsonOK(w, 200, map[string]any{"disks": disks})
+	jsonOK(w, 200, map[string]any{"targets": targets})
 }
 
-func (s *Server) spaceDisk(w http.ResponseWriter, r *http.Request, name string) (spaceDisk, bool) {
+func (s *Server) spaceTarget(w http.ResponseWriter, r *http.Request, id string) (spaceTarget, bool) {
-	for _, d := range s.spaceDisks(r.Context()) {
+	for _, t := range s.spaceTargets(r.Context()) {
-		if d.Name == name {
+		if t.ID == id {
-			return d, true
+			return t, true
 		}
 	}
-	jsonErr(w, 404, "no such disk")
+	jsonErr(w, 404, "no such disk or pool")
-	return spaceDisk{}, false
+	return spaceTarget{}, false
 }
 
 func (s *Server) spaceStatus(w http.ResponseWriter, r *http.Request) {
@@ -114,16 +148,16 @@ func (s *Server) spaceStatus(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) spaceScan(w http.ResponseWriter, r *http.Request) {
-	d, ok := s.spaceDisk(w, r, r.PathValue("disk"))
+	t, ok := s.spaceTarget(w, r, r.PathValue("disk"))
 	if !ok {
 		return
 	}
-	st, err := s.space.Start(d.Name, d.Roots)
+	st, err := s.space.Start(t.ID, t.Roots)
 	if err != nil {
 		jsonErr(w, 409, err.Error())
 		return
 	}
-	log.Printf("space: scan of %s (%s) started by %s", d.Name, strings.Join(d.Roots, " "), clientIP(r))
+	log.Printf("space: scan of %s (%s) started by %s", t.ID, strings.Join(t.Roots, " "), clientIP(r))
 	jsonOK(w, 202, st)
 }