diff options
| -rw-r--r-- | internal/fusefrontend/args.go | 3 | ||||
| -rw-r--r-- | internal/fusefrontend/node_helpers.go | 3 | ||||
| -rw-r--r-- | internal/fusefrontend/root_node.go | 10 | ||||
| -rw-r--r-- | internal/inomap/inomap.go | 11 | ||||
| -rw-r--r-- | mount.go | 10 | ||||
| -rw-r--r-- | tests/cli/cli_test.go | 47 |
6 files changed, 79 insertions, 5 deletions
diff --git a/internal/fusefrontend/args.go b/internal/fusefrontend/args.go index 5eb6bff..ae1c30c 100644 --- a/internal/fusefrontend/args.go +++ b/internal/fusefrontend/args.go @@ -46,4 +46,7 @@ type Args struct { Suid bool // Enable the FUSE kernel_cache option KernelCache bool + // SharedStorage disables caching & hard link tracking, + // enabled via cli flag "-sharedstorage" + SharedStorage bool } diff --git a/internal/fusefrontend/node_helpers.go b/internal/fusefrontend/node_helpers.go index ad92043..f99e6df 100644 --- a/internal/fusefrontend/node_helpers.go +++ b/internal/fusefrontend/node_helpers.go @@ -102,8 +102,9 @@ func (n *Node) prepareAtSyscall(child string) (dirfd int, cName string, errno sy // newChild attaches a new child inode to n. // The passed-in `st` will be modified to get a unique inode number. func (n *Node) newChild(ctx context.Context, st *syscall.Stat_t, out *fuse.EntryOut) *fs.Inode { - // Get unique inode number rn := n.rootNode() + // Get stable inode number based on underlying (device,ino) pair + // (or set to zero in case of `-sharestorage`) rn.inoMap.TranslateStat(st) out.Attr.FromStat(st) // Create child node diff --git a/internal/fusefrontend/root_node.go b/internal/fusefrontend/root_node.go index e03e250..bdefafa 100644 --- a/internal/fusefrontend/root_node.go +++ b/internal/fusefrontend/root_node.go @@ -50,7 +50,7 @@ type RootNode struct { IsIdle uint32 // inoMap translates inode numbers from different devices to unique inode // numbers. - inoMap *inomap.InoMap + inoMap inomap.TranslateStater } func NewRootNode(args Args, c *contentenc.ContentEnc, n nametransform.NameTransformer) *RootNode { @@ -60,12 +60,18 @@ func NewRootNode(args Args, c *contentenc.ContentEnc, n nametransform.NameTransf if len(args.Exclude) > 0 { tlog.Warn.Printf("Forward mode does not support -exclude") } - return &RootNode{ + rn := &RootNode{ args: args, nameTransform: n, contentEnc: c, inoMap: inomap.New(), } + // In `-sharedstorage` mode we always set the inode number to zero. + // This makes go-fuse generate a new inode number for each lookup. + if args.SharedStorage { + rn.inoMap = &inomap.TranslateStatZero{} + } + return rn } // mangleOpenFlags is used by Create() and Open() to convert the open flags the user diff --git a/internal/inomap/inomap.go b/internal/inomap/inomap.go index 82d50b0..0977a46 100644 --- a/internal/inomap/inomap.go +++ b/internal/inomap/inomap.go @@ -104,3 +104,14 @@ func (m *InoMap) TranslateStat(st *syscall.Stat_t) { in := QInoFromStat(st) st.Ino = m.Translate(in) } + +type TranslateStater interface { + TranslateStat(st *syscall.Stat_t) +} + +// TranslateStatZero always sets st.Ino to zero. Used for `-sharedstorage`. +type TranslateStatZero struct{} + +func (z TranslateStatZero) TranslateStat(st *syscall.Stat_t) { + st.Ino = 0 +} @@ -280,6 +280,7 @@ func initFuseFrontend(args *argContainer) (rootNode fs.InodeEmbedder, wipeKeys f ExcludeFrom: args.excludeFrom, Suid: args.suid, KernelCache: args.kernel_cache, + SharedStorage: args.sharedstorage, } // confFile is nil when "-zerokey" or "-masterkey" was used if confFile != nil { @@ -349,7 +350,11 @@ func initGoFuse(rootNode fs.InodeEmbedder, args *argContainer) *fuse.Server { if args.sharedstorage { // sharedstorage mode sets all cache timeouts to zero so changes to the // backing shared storage show up immediately. - fuseOpts = &fs.Options{} + // Hard links are disabled by using automatically incrementing + // inode numbers provided by go-fuse. + fuseOpts = &fs.Options{ + FirstAutomaticIno: 1000, + } } else { fuseOpts = &fs.Options{ // These options are to be compatible with libfuse defaults, @@ -421,7 +426,8 @@ func initGoFuse(rootNode fs.InodeEmbedder, args *argContainer) *fuse.Server { } else if args.rw { mOpts.Options = append(mOpts.Options, "rw") } - // If both "nosuid" and "suid" were passed, the safer option wins. + // If both "nosuid" & "suid", "nodev" & "dev", etc were passed, the safer + // option wins. if args.nosuid { mOpts.Options = append(mOpts.Options, "nosuid") } else if args.suid { diff --git a/tests/cli/cli_test.go b/tests/cli/cli_test.go index 2872592..23cea05 100644 --- a/tests/cli/cli_test.go +++ b/tests/cli/cli_test.go @@ -822,3 +822,50 @@ func TestInitNotEmpty(t *testing.T) { t.Fatalf("wrong exit code: have=%d, want=%d", exitCode, exitcodes.CipherDir) } } + +// TestSharedstorage checks that `-sharedstorage` hands out arbitrary inode +// numbers (no hard link tracking) +func TestSharedstorage(t *testing.T) { + dir := test_helpers.InitFS(t) + mnt := dir + ".mnt" + err := os.Mkdir(mnt, 0700) + if err != nil { + t.Fatal(err) + } + test_helpers.MountOrFatal(t, dir, mnt, "-extpass=echo test", "-sharedstorage") + defer test_helpers.UnmountPanic(mnt) + foo1 := mnt + "/foo1" + foo2 := mnt + "/foo2" + if err := ioutil.WriteFile(foo1, nil, 0755); err != nil { + t.Fatal(err) + } + if err := os.Link(foo1, foo2); err != nil { + t.Fatal(err) + } + var st1, st2, st3 syscall.Stat_t + if err := syscall.Stat(foo1, &st1); err != nil { + t.Fatal(err) + } + // The link show show a new inode number + if err := syscall.Stat(foo2, &st2); err != nil { + t.Fatal(err) + } + // Stat()'ing again should give us again a new inode number + if err := syscall.Stat(foo2, &st3); err != nil { + t.Fatal(err) + } + if st1.Ino == st2.Ino || st2.Ino == st3.Ino || st1.Ino == st3.Ino { + t.Error(st1.Ino, st2.Ino, st3.Ino) + } + // Check that we we don't have stat caching. New length should show up + // on the hard link immediately. + if err := ioutil.WriteFile(foo1, []byte("xxxxxx"), 0755); err != nil { + t.Fatal(err) + } + if err := syscall.Stat(foo2, &st2); err != nil { + t.Fatal(err) + } + if st2.Size != 6 { + t.Fatal(st2.Size) + } +} |