From c3c9513e6504276698ed1f50a259d4333476acf8 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Mon, 2 Aug 2021 20:01:26 +0200 Subject: fusefrontend: add quirks for MacOS ExFAT This also moves the quirks logic into fusefrontend. Fixes https://github.com/rfjakob/gocryptfs/issues/585 --- internal/fusefrontend/file.go | 2 +- internal/fusefrontend/node_helpers.go | 2 +- internal/fusefrontend/quirks.go | 52 +++++++++++++++++++++++++++++++++++ internal/fusefrontend/root_node.go | 4 +++ mount.go | 17 ------------ 5 files changed, 58 insertions(+), 19 deletions(-) create mode 100644 internal/fusefrontend/quirks.go diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index 4866e65..304ba7f 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -118,7 +118,7 @@ func (f *File) createHeader() (fileID []byte, err error) { h := contentenc.RandomHeader() buf := h.Pack() // Prevent partially written (=corrupt) header by preallocating the space beforehand - if !f.rootNode.args.NoPrealloc { + if !f.rootNode.args.NoPrealloc && f.rootNode.quirks&quirkBrokenFalloc == 0 { err = syscallcompat.EnospcPrealloc(f.intFd(), 0, contentenc.HeaderLen) if err != nil { if !syscallcompat.IsENOSPC(err) { diff --git a/internal/fusefrontend/node_helpers.go b/internal/fusefrontend/node_helpers.go index 31954f3..2f361f6 100644 --- a/internal/fusefrontend/node_helpers.go +++ b/internal/fusefrontend/node_helpers.go @@ -87,7 +87,7 @@ func (n *Node) newChild(ctx context.Context, st *syscall.Stat_t, out *fuse.Entry out.Attr.FromStat(st) var gen uint64 = 1 - if rn.args.SharedStorage { + if rn.args.SharedStorage || rn.quirks&quirkDuplicateIno1 != 0 { // Make each directory entry a unique node by using a unique generation // value - see the comment at RootNode.gen for details. gen = atomic.AddUint64(&rn.gen, 1) diff --git a/internal/fusefrontend/quirks.go b/internal/fusefrontend/quirks.go new file mode 100644 index 0000000..2979c84 --- /dev/null +++ b/internal/fusefrontend/quirks.go @@ -0,0 +1,52 @@ +package fusefrontend + +import ( + "runtime" + + "golang.org/x/sys/unix" + + "github.com/rfjakob/gocryptfs/internal/tlog" +) + +const ( + quirkBrokenFalloc = uint64(1 << iota) + quirkDuplicateIno1 +) + +func detectQuirks(cipherdir string) (q uint64) { + const ( + // From Linux' man statfs + BTRFS_SUPER_MAGIC = 0x9123683e + + // From https://github.com/rfjakob/gocryptfs/issues/585#issuecomment-887370065 + DARWIN_EXFAT_MAGIC = 35 + ) + + var st unix.Statfs_t + err := unix.Statfs(cipherdir, &st) + if err != nil { + tlog.Warn.Printf("detectQuirks: Statfs on %q failed: %v", cipherdir, err) + return 0 + } + + logQuirk := func(s string) { + tlog.Info.Printf(tlog.ColorYellow + "detectQuirks: " + s + tlog.ColorReset) + } + + // Preallocation on Btrfs is broken ( https://github.com/rfjakob/gocryptfs/issues/395 ) + // and slow ( https://github.com/rfjakob/gocryptfs/issues/63 ). + // + // Cast to uint32 avoids compile error on arm: "constant 2435016766 overflows int32" + if uint32(st.Type) == BTRFS_SUPER_MAGIC { + logQuirk("Btrfs detected, forcing -noprealloc. See https://github.com/rfjakob/gocryptfs/issues/395 for why.") + q |= quirkBrokenFalloc + } + // On MacOS ExFAT, all empty files share inode number 1: + // https://github.com/rfjakob/gocryptfs/issues/585 + if runtime.GOOS == "darwin" && st.Type == DARWIN_EXFAT_MAGIC { + logQuirk("ExFAT detected, disabling hard links. See https://github.com/rfjakob/gocryptfs/issues/585 for why.") + q |= quirkDuplicateIno1 + } + + return q +} diff --git a/internal/fusefrontend/root_node.go b/internal/fusefrontend/root_node.go index 46bee4a..9905d66 100644 --- a/internal/fusefrontend/root_node.go +++ b/internal/fusefrontend/root_node.go @@ -57,6 +57,9 @@ type RootNode struct { // makes go-fuse hand out separate FUSE Node IDs for each, and prevents // bizarre problems when inode numbers are reused behind our back. gen uint64 + // quirks is a bitmap that enables workaround for quirks in the filesystem + // backing the cipherdir + quirks uint64 } func NewRootNode(args Args, c *contentenc.ContentEnc, n *nametransform.NameTransform) *RootNode { @@ -76,6 +79,7 @@ func NewRootNode(args Args, c *contentenc.ContentEnc, n *nametransform.NameTrans contentEnc: c, inoMap: inomap.New(), dirCache: dirCache{ivLen: ivLen}, + quirks: detectQuirks(args.Cipherdir), } return rn } diff --git a/mount.go b/mount.go index b146660..ab4ad81 100644 --- a/mount.go +++ b/mount.go @@ -19,8 +19,6 @@ import ( "syscall" "time" - "golang.org/x/sys/unix" - "github.com/hanwen/go-fuse/v2/fs" "github.com/hanwen/go-fuse/v2/fuse" @@ -102,21 +100,6 @@ func doMount(args *argContainer) { } }() } - // Preallocation on Btrfs is broken ( https://github.com/rfjakob/gocryptfs/issues/395 ) - // and slow ( https://github.com/rfjakob/gocryptfs/issues/63 ). - if !args.noprealloc { - // darwin does not have unix.BTRFS_SUPER_MAGIC, so we define it here - const BTRFS_SUPER_MAGIC = 0x9123683e - var st unix.Statfs_t - err = unix.Statfs(args.cipherdir, &st) - // Cast to uint32 avoids compile error on arm: "constant 2435016766 overflows int32" - if err == nil && uint32(st.Type) == BTRFS_SUPER_MAGIC { - tlog.Info.Printf(tlog.ColorYellow + - "Btrfs detected, forcing -noprealloc. See https://github.com/rfjakob/gocryptfs/issues/395 for why." + - tlog.ColorReset) - args.noprealloc = true - } - } // Initialize gocryptfs (read config file, ask for password, ...) fs, wipeKeys := initFuseFrontend(args) // Try to wipe secret keys from memory after unmount -- cgit v1.2.3