diff options
Diffstat (limited to 'cmd')
| -rw-r--r-- | cmd/btrfs-mount/main.go | 4 | ||||
| -rw-r--r-- | cmd/btrfs-mount/subvol_fuse.go | 104 |
2 files changed, 95 insertions, 13 deletions
diff --git a/cmd/btrfs-mount/main.go b/cmd/btrfs-mount/main.go index 64cae30..4451e7a 100644 --- a/cmd/btrfs-mount/main.go +++ b/cmd/btrfs-mount/main.go @@ -68,7 +68,7 @@ func Main(ctx context.Context, mountpoint string, imgfilenames ...string) (err e } return fuse.Unmount(os.Args[1]) }) - grp.Go("main", func(ctx context.Context) error { + grp.Go("mount", func(ctx context.Context) error { defer atomic.StoreUint32(&mounted, 0) rootSubvol := &Subvolume{ Subvolume: btrfs.Subvolume{ @@ -78,7 +78,7 @@ func Main(ctx context.Context, mountpoint string, imgfilenames ...string) (err e DeviceName: tryAbs(imgfilenames[0]), Mountpoint: mountpoint, } - return rootSubvol.Run(ctx) + return rootSubvol.Run(ctx, false) }) return grp.Wait() } diff --git a/cmd/btrfs-mount/subvol_fuse.go b/cmd/btrfs-mount/subvol_fuse.go index 3a22c9a..522da85 100644 --- a/cmd/btrfs-mount/subvol_fuse.go +++ b/cmd/btrfs-mount/subvol_fuse.go @@ -2,11 +2,16 @@ package main import ( "context" + "errors" "fmt" + "io" + "path/filepath" + "sync" "sync/atomic" "syscall" "github.com/datawire/dlib/dcontext" + "github.com/datawire/dlib/dgroup" "github.com/datawire/dlib/dlog" "github.com/jacobsa/fuse" "github.com/jacobsa/fuse/fuseops" @@ -14,6 +19,7 @@ import ( "lukeshu.com/btrfs-tools/pkg/btrfs" "lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem" + "lukeshu.com/btrfs-tools/pkg/linux" "lukeshu.com/btrfs-tools/pkg/util" ) @@ -34,13 +40,16 @@ type Subvolume struct { lastHandle uint64 dirHandles util.SyncMap[fuseops.HandleID, *dirState] fileHandles util.SyncMap[fuseops.HandleID, *fileState] + + subvolMu sync.Mutex + subvols map[string]struct{} + grp *dgroup.Group } -func (sv *Subvolume) Run(ctx context.Context) error { - mount, err := fuse.Mount( - sv.Mountpoint, - fuseutil.NewFileSystemServer(sv), - &fuse.MountConfig{ +func (sv *Subvolume) Run(ctx context.Context, isSubvol bool) error { + sv.grp = dgroup.NewGroup(ctx, dgroup.GroupConfig{}) + sv.grp.Go("self", func(ctx context.Context) error { + cfg := &fuse.MountConfig{ OpContext: ctx, ErrorLogger: dlog.StdLogger(ctx, dlog.LogLevelError), DebugLogger: dlog.StdLogger(ctx, dlog.LogLevelDebug), @@ -49,11 +58,24 @@ func (sv *Subvolume) Run(ctx context.Context) error { Subtype: "btrfs", ReadOnly: true, - }) - if err != nil { - return err - } - return mount.Join(dcontext.HardContext(ctx)) + + Options: map[string]string{ + "allow_other": "", + }, + } + if isSubvol { + //cfg.Options["nonempty"] = "" + } + mount, err := fuse.Mount( + sv.Mountpoint, + fuseutil.NewFileSystemServer(sv), + cfg) + if err != nil { + return err + } + return mount.Join(dcontext.HardContext(ctx)) + }) + return sv.grp.Wait() } func (sv *Subvolume) newHandle() fuseops.HandleID { @@ -75,6 +97,54 @@ func inodeItemToFUSE(itemBody btrfsitem.Inode) fuseops.InodeAttributes { } } +func (sv *Subvolume) LoadDir(inode btrfs.ObjID) (val *btrfs.Dir, err error) { + val, err = sv.Subvolume.LoadDir(inode) + if val != nil { + haveSubvolumes := false + for _, index := range util.SortedMapKeys(val.ChildrenByIndex) { + entry := val.ChildrenByIndex[index] + if entry.Location.ItemType == btrfsitem.ROOT_ITEM_KEY { + haveSubvolumes = true + break + } + } + if haveSubvolumes { + abspath, _err := val.AbsPath() + if _err != nil { + return + } + sv.subvolMu.Lock() + for _, index := range util.SortedMapKeys(val.ChildrenByIndex) { + entry := val.ChildrenByIndex[index] + if entry.Location.ItemType != btrfsitem.ROOT_ITEM_KEY { + continue + } + if sv.subvols == nil { + sv.subvols = make(map[string]struct{}) + } + subMountpoint := filepath.Join(abspath, string(entry.Name)) + if _, alreadyMounted := sv.subvols[subMountpoint]; !alreadyMounted { + sv.subvols[subMountpoint] = struct{}{} + workerName := fmt.Sprintf("%d-%s", val.Inode, filepath.Base(subMountpoint)) + sv.grp.Go(workerName, func(ctx context.Context) error { + subSv := &Subvolume{ + Subvolume: btrfs.Subvolume{ + FS: sv.FS, + TreeID: entry.Location.ObjectID, + }, + DeviceName: sv.DeviceName, + Mountpoint: filepath.Join(sv.Mountpoint, subMountpoint[1:]), + } + return subSv.Run(ctx, true) + }) + } + } + sv.subvolMu.Unlock() + } + } + return +} + func (sv *Subvolume) StatFS(_ context.Context, op *fuseops.StatFSOp) error { // See linux.git/fs/btrfs/super.c:btrfs_statfs() sb, err := sv.FS.Superblock() @@ -116,7 +186,16 @@ func (sv *Subvolume) LookUpInode(_ context.Context, op *fuseops.LookUpInodeOp) e return syscall.ENOENT } if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY { - return fmt.Errorf("child %q is not an inode: %w", op.Name, syscall.ENOSYS) + op.Entry = fuseops.ChildInodeEntry{ + Child: 2, // an inode number that a real file will never have + Attributes: fuseops.InodeAttributes{ + Nlink: 1, + Mode: uint32(linux.ModeFmtDir | 0700), + //Uid: 1000, // TODO + //Gid: 1000, // TODO + }, + } + return nil } bareInode, err := sv.LoadBareInode(entry.Location.ObjectID) if err != nil { @@ -240,6 +319,9 @@ func (sv *Subvolume) ReadFile(_ context.Context, op *fuseops.ReadFileOp) error { var err error op.BytesRead, err = state.File.ReadAt(dat, op.Offset) + if errors.Is(err, io.EOF) { + err = nil + } return err } |