From 73b7c1e933f5275f2741a5b32f501bc8353a359a Mon Sep 17 00:00:00 2001
From: kwnam <kw.nam@navercorp.com>
Date: Wed, 18 Dec 2024 18:52:52 +0900
Subject: [PATCH] Support all-squash mount option

---
 cmd/mount_unix.go   | 83 ++++++++++++++++++++++++++++-----------------
 pkg/fuse/context.go |  5 +++
 pkg/vfs/vfs.go      |  7 ++--
 3 files changed, 60 insertions(+), 35 deletions(-)

diff --git a/cmd/mount_unix.go b/cmd/mount_unix.go
index d404e2811778..7fec5e691a86 100644
--- a/cmd/mount_unix.go
+++ b/cmd/mount_unix.go
@@ -315,6 +315,10 @@ func fuseFlags() []cli.Flag {
 			Name:  "root-squash",
 			Usage: "mapping local root user (uid = 0) to another one specified as <uid>:<gid>",
 		},
+		&cli.StringFlag{
+			Name:  "all-squash",
+			Usage: "mapping all users to another one specified as <uid>:<gid>",
+		},
 		&cli.BoolFlag{
 			Name:  "prefix-internal",
 			Usage: "add '.jfs' prefix to all internal files",
@@ -828,6 +832,45 @@ func launchMount(mp string, conf *vfs.Config) error {
 	}
 }
 
+func getNobodyUIDGID() (uint32, uint32) {
+	var uid, gid uint32 = 65534, 65534
+	if u, err := user.Lookup("nobody"); err == nil {
+		nobody, err := strconv.ParseUint(u.Uid, 10, 32)
+		if err != nil {
+			logger.Fatalf("invalid uid: %s", u.Uid)
+		}
+		uid = uint32(nobody)
+	}
+	if g, err := user.LookupGroup("nogroup"); err == nil {
+		nogroup, err := strconv.ParseUint(g.Gid, 10, 32)
+		if err != nil {
+			logger.Fatalf("invalid gid: %s", g.Gid)
+		}
+		gid = uint32(nogroup)
+	}
+	return uid, gid
+}
+
+func parseUIDGID(input string, defaultUid uint32, defaultGid uint32) (uint32, uint32) {
+	ss := strings.SplitN(strings.TrimSpace(input), ":", 2)
+	uid, gid := defaultUid, defaultGid
+	if ss[0] != "" {
+		u, err := strconv.ParseUint(ss[0], 10, 32)
+		if err != nil {
+			logger.Fatalf("invalid uid: %s", ss[0])
+		}
+		uid = uint32(u)
+	}
+	if len(ss) == 2 && ss[1] != "" {
+		g, err := strconv.ParseUint(ss[1], 10, 32)
+		if err != nil {
+			logger.Fatalf("invalid gid: %s", ss[1])
+		}
+		gid = uint32(g)
+	}
+	return uid, gid
+}
+
 func mountMain(v *vfs.VFS, c *cli.Context) {
 	if os.Getuid() == 0 {
 		disableUpdatedb()
@@ -838,39 +881,15 @@ func mountMain(v *vfs.VFS, c *cli.Context) {
 	conf.DirEntryTimeout = utils.Duration(c.String("dir-entry-cache"))
 	conf.NonDefaultPermission = c.Bool("non-default-permission")
 	rootSquash := c.String("root-squash")
+	allSquash := c.String("all-squash")
+	nobodyUid, nobodyGid := getNobodyUIDGID()
 	if rootSquash != "" {
-		var uid, gid uint32 = 65534, 65534
-		if u, err := user.Lookup("nobody"); err == nil {
-			nobody, err := strconv.ParseUint(u.Uid, 10, 32)
-			if err != nil {
-				logger.Fatalf("invalid uid: %s", u.Uid)
-			}
-			uid = uint32(nobody)
-		}
-		if g, err := user.LookupGroup("nogroup"); err == nil {
-			nogroup, err := strconv.ParseUint(g.Gid, 10, 32)
-			if err != nil {
-				logger.Fatalf("invalid gid: %s", g.Gid)
-			}
-			gid = uint32(nogroup)
-		}
-
-		ss := strings.SplitN(strings.TrimSpace(rootSquash), ":", 2)
-		if ss[0] != "" {
-			u, err := strconv.ParseUint(ss[0], 10, 32)
-			if err != nil {
-				logger.Fatalf("invalid uid: %s", ss[0])
-			}
-			uid = uint32(u)
-		}
-		if len(ss) == 2 && ss[1] != "" {
-			g, err := strconv.ParseUint(ss[1], 10, 32)
-			if err != nil {
-				logger.Fatalf("invalid gid: %s", ss[1])
-			}
-			gid = uint32(g)
-		}
-		conf.RootSquash = &vfs.RootSquash{Uid: uid, Gid: gid}
+		uid, gid := parseUIDGID(rootSquash, nobodyUid, nobodyGid)
+		conf.RootSquash = &vfs.AnonymousAccount{Uid: uid, Gid: gid}
+	}
+	if allSquash != "" {
+		uid, gid := parseUIDGID(allSquash, nobodyUid, nobodyGid)
+		conf.AllSquash = &vfs.AnonymousAccount{Uid: uid, Gid: gid}
 	}
 	logger.Infof("Mounting volume %s at %s ...", conf.Format.Name, conf.Meta.MountPoint)
 	err := fuse.Serve(v, c.String("o"), c.Bool("enable-xattr"), c.Bool("enable-ioctl"))
diff --git a/pkg/fuse/context.go b/pkg/fuse/context.go
index c4b985c1921e..54ff55162537 100644
--- a/pkg/fuse/context.go
+++ b/pkg/fuse/context.go
@@ -68,6 +68,11 @@ func (fs *fileSystem) newContext(cancel <-chan struct{}, header *fuse.InHeader)
 		ctx.header.Uid = fs.conf.RootSquash.Uid
 		ctx.header.Gid = fs.conf.RootSquash.Gid
 	}
+	if fs.conf.AllSquash != nil {
+		ctx.checkPermission = true
+		ctx.header.Uid = fs.conf.AllSquash.Uid
+		ctx.header.Gid = fs.conf.AllSquash.Gid
+	}
 	return ctx
 }
 
diff --git a/pkg/vfs/vfs.go b/pkg/vfs/vfs.go
index f808f0fed530..f9b855875b20 100644
--- a/pkg/vfs/vfs.go
+++ b/pkg/vfs/vfs.go
@@ -128,8 +128,9 @@ type Config struct {
 	AccessLog            string `json:",omitempty"`
 	PrefixInternal       bool
 	HideInternal         bool
-	RootSquash           *RootSquash `json:",omitempty"`
-	NonDefaultPermission bool        `json:",omitempty"`
+	RootSquash           *AnonymousAccount `json:",omitempty"`
+	AllSquash            *AnonymousAccount `json:",omitempty"`
+	NonDefaultPermission bool              `json:",omitempty"`
 
 	Pid       int
 	PPid      int
@@ -138,7 +139,7 @@ type Config struct {
 	FuseOpts  *FuseOptions `json:",omitempty"`
 }
 
-type RootSquash struct {
+type AnonymousAccount struct {
 	Uid uint32
 	Gid uint32
 }