diff options
Diffstat (limited to 'pkg')
-rw-r--r-- | pkg/abi/linux/fuse.go | 105 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/BUILD | 4 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/connection.go | 234 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/dev.go | 13 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/dev_test.go | 19 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/fusefs.go | 22 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/fuse/init.go | 166 | ||||
-rw-r--r-- | pkg/syserror/syserror.go | 1 |
8 files changed, 512 insertions, 52 deletions
diff --git a/pkg/abi/linux/fuse.go b/pkg/abi/linux/fuse.go index d3ebbccc4..5c6ffe4a3 100644 --- a/pkg/abi/linux/fuse.go +++ b/pkg/abi/linux/fuse.go @@ -141,3 +141,108 @@ type FUSEWriteIn struct { _ uint32 } + +// FUSE_INIT flags, consistent with the ones in include/uapi/linux/fuse.h. +const ( + FUSE_ASYNC_READ = 1 << 0 + FUSE_POSIX_LOCKS = 1 << 1 + FUSE_FILE_OPS = 1 << 2 + FUSE_ATOMIC_O_TRUNC = 1 << 3 + FUSE_EXPORT_SUPPORT = 1 << 4 + FUSE_BIG_WRITES = 1 << 5 + FUSE_DONT_MASK = 1 << 6 + FUSE_SPLICE_WRITE = 1 << 7 + FUSE_SPLICE_MOVE = 1 << 8 + FUSE_SPLICE_READ = 1 << 9 + FUSE_FLOCK_LOCKS = 1 << 10 + FUSE_HAS_IOCTL_DIR = 1 << 11 + FUSE_AUTO_INVAL_DATA = 1 << 12 + FUSE_DO_READDIRPLUS = 1 << 13 + FUSE_READDIRPLUS_AUTO = 1 << 14 + FUSE_ASYNC_DIO = 1 << 15 + FUSE_WRITEBACK_CACHE = 1 << 16 + FUSE_NO_OPEN_SUPPORT = 1 << 17 + FUSE_PARALLEL_DIROPS = 1 << 18 + FUSE_HANDLE_KILLPRIV = 1 << 19 + FUSE_POSIX_ACL = 1 << 20 + FUSE_ABORT_ERROR = 1 << 21 + FUSE_MAX_PAGES = 1 << 22 + FUSE_CACHE_SYMLINKS = 1 << 23 + FUSE_NO_OPENDIR_SUPPORT = 1 << 24 + FUSE_EXPLICIT_INVAL_DATA = 1 << 25 + FUSE_MAP_ALIGNMENT = 1 << 26 +) + +// currently supported FUSE protocol version numbers. +const ( + FUSE_KERNEL_VERSION = 7 + FUSE_KERNEL_MINOR_VERSION = 31 +) + +// FUSEInitIn is the request sent by the kernel to the daemon, +// to negotiate the version and flags. +// +// +marshal +type FUSEInitIn struct { + // Major version supported by kernel. + Major uint32 + + // Minor version supported by the kernel. + Minor uint32 + + // MaxReadahead is the maximum number of bytes to read-ahead + // decided by the kernel. + MaxReadahead uint32 + + // Flags of this init request. + Flags uint32 +} + +// FUSEInitOut is the reply sent by the daemon to the kernel +// for FUSEInitIn. +// +// +marshal +type FUSEInitOut struct { + // Major version supported by daemon. + Major uint32 + + // Minor version supported by daemon. + Minor uint32 + + // MaxReadahead is the maximum number of bytes to read-ahead. + // Decided by the daemon, after receiving the value from kernel. + MaxReadahead uint32 + + // Flags of this init reply. + Flags uint32 + + // MaxBackground is the maximum number of pending background requests + // that the daemon wants. + MaxBackground uint16 + + // CongestionThreshold is the daemon-decided threshold for + // the number of the pending background requests. + CongestionThreshold uint16 + + // MaxWrite is the daemon's maximum size of a write buffer. + // Kernel adjusts it to the minimum (fuse/init.go:fuseMinMaxWrite). + // if the value from daemon is too small. + MaxWrite uint32 + + // TimeGran is the daemon's time granularity for mtime and ctime metadata. + // The unit is nanosecond. + // Value should be power of 10. + // 1 indicates full nanosecond granularity support. + TimeGran uint32 + + // MaxPages is the daemon's maximum number of pages for one write operation. + // Kernel adjusts it to the maximum (fuse/init.go:FUSE_MAX_MAX_PAGES). + // if the value from daemon is too large. + MaxPages uint16 + + // MapAlignment is an unknown field and not used by this package at this moment. + // Use as a placeholder to be consistent with the FUSE protocol. + MapAlignment uint16 + + _ [8]uint32 +} diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD index 67649e811..999111deb 100644 --- a/pkg/sentry/fsimpl/fuse/BUILD +++ b/pkg/sentry/fsimpl/fuse/BUILD @@ -21,6 +21,7 @@ go_library( "connection.go", "dev.go", "fusefs.go", + "init.go", "register.go", "request_list.go", ], @@ -44,14 +45,13 @@ go_library( ) go_test( - name = "dev_test", + name = "fuse_test", size = "small", srcs = ["dev_test.go"], library = ":fuse", deps = [ "//pkg/abi/linux", "//pkg/sentry/fsimpl/testutil", - "//pkg/sentry/fsimpl/tmpfs", "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", "//pkg/sentry/vfs", diff --git a/pkg/sentry/fsimpl/fuse/connection.go b/pkg/sentry/fsimpl/fuse/connection.go index f330da0bd..6df2728ab 100644 --- a/pkg/sentry/fsimpl/fuse/connection.go +++ b/pkg/sentry/fsimpl/fuse/connection.go @@ -17,6 +17,8 @@ package fuse import ( "errors" "fmt" + "sync" + "sync/atomic" "syscall" "gvisor.dev/gvisor/pkg/abi/linux" @@ -25,18 +27,29 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/waiter" "gvisor.dev/gvisor/tools/go_marshal/marshal" ) -// MaxActiveRequestsDefault is the default setting controlling the upper bound +// maxActiveRequestsDefault is the default setting controlling the upper bound // on the number of active requests at any given time. -const MaxActiveRequestsDefault = 10000 +const maxActiveRequestsDefault = 10000 -var ( - // Ordinary requests have even IDs, while interrupts IDs are odd. - InitReqBit uint64 = 1 - ReqIDStep uint64 = 2 +// Ordinary requests have even IDs, while interrupts IDs are odd. +// Used to increment the unique ID for each FUSE request. +var reqIDStep uint64 = 2 + +const ( + // fuseDefaultMaxBackground is the default value for MaxBackground. + fuseDefaultMaxBackground = 12 + + // fuseDefaultCongestionThreshold is the default value for CongestionThreshold, + // and is 75% of the default maximum of MaxGround. + fuseDefaultCongestionThreshold = (fuseDefaultMaxBackground * 3 / 4) + + // fuseDefaultMaxPagesPerReq is the default value for MaxPagesPerReq. + fuseDefaultMaxPagesPerReq = 32 ) // Request represents a FUSE operation request that hasn't been sent to the @@ -61,17 +74,125 @@ type Response struct { data []byte } -// Connection is the struct by which the sentry communicates with the FUSE server daemon. -type Connection struct { +// connection is the struct by which the sentry communicates with the FUSE server daemon. +type connection struct { fd *DeviceFD - // MaxWrite is the daemon's maximum size of a write buffer. - // This is negotiated during FUSE_INIT. - MaxWrite uint32 + // The following FUSE_INIT flags are currently unsupported by this implementation: + // - FUSE_ATOMIC_O_TRUNC: requires open(..., O_TRUNC) + // - FUSE_EXPORT_SUPPORT + // - FUSE_HANDLE_KILLPRIV + // - FUSE_POSIX_LOCKS: requires POSIX locks + // - FUSE_FLOCK_LOCKS: requires POSIX locks + // - FUSE_AUTO_INVAL_DATA: requires page caching eviction + // - FUSE_EXPLICIT_INVAL_DATA: requires page caching eviction + // - FUSE_DO_READDIRPLUS/FUSE_READDIRPLUS_AUTO: requires FUSE_READDIRPLUS implementation + // - FUSE_ASYNC_DIO + // - FUSE_POSIX_ACL: affects defaultPermissions, posixACL, xattr handler + + // initialized after receiving FUSE_INIT reply. + // Until it's set, suspend sending FUSE requests. + // Use SetInitialized() and IsInitialized() for atomic access. + initialized int32 + + // initializedChan is used to block requests before initialization. + initializedChan chan struct{} + + // blocked when there are too many outstading backgrounds requests (NumBackground == MaxBackground). + // TODO(gvisor.dev/issue/3185): update the numBackground accordingly; use a channel to block. + blocked bool + + // connected (connection established) when a new FUSE file system is created. + // Set to false when: + // umount, + // connection abort, + // device release. + connected bool + + // aborted via sysfs. + // TODO(gvisor.dev/issue/3185): abort all queued requests. + aborted bool + + // connInitError if FUSE_INIT encountered error (major version mismatch). + // Only set in INIT. + connInitError bool + + // connInitSuccess if FUSE_INIT is successful. + // Only set in INIT. + // Used for destory. + connInitSuccess bool + + // TODO(gvisor.dev/issue/3185): All the queue logic are working in progress. + + // NumberBackground is the number of requests in the background. + numBackground uint16 + + // congestionThreshold for NumBackground. + // Negotiated in FUSE_INIT. + congestionThreshold uint16 + + // maxBackground is the maximum number of NumBackground. + // Block connection when it is reached. + // Negotiated in FUSE_INIT. + maxBackground uint16 + + // numActiveBackground is the number of requests in background and has being marked as active. + numActiveBackground uint16 + + // numWating is the number of requests waiting for completion. + numWaiting uint32 + + // TODO(gvisor.dev/issue/3185): BgQueue + // some queue for background queued requests. + + // bgLock protects: + // MaxBackground, CongestionThreshold, NumBackground, + // NumActiveBackground, BgQueue, Blocked. + bgLock sync.Mutex + + // maxRead is the maximum size of a read buffer in in bytes. + maxRead uint32 + + // maxWrite is the maximum size of a write buffer in bytes. + // Negotiated in FUSE_INIT. + maxWrite uint32 + + // maxPages is the maximum number of pages for a single request to use. + // Negotiated in FUSE_INIT. + maxPages uint16 + + // minor version of the FUSE protocol. + // Negotiated and only set in INIT. + minor uint32 + + // asyncRead if read pages asynchronously. + // Negotiated and only set in INIT. + asyncRead bool + + // abortErr is true if kernel need to return an unique read error after abort. + // Negotiated and only set in INIT. + abortErr bool + + // writebackCache is true for write-back cache policy, + // false for write-through policy. + // Negotiated and only set in INIT. + writebackCache bool + + // cacheSymlinks if filesystem needs to cache READLINK responses in page cache. + // Negotiated and only set in INIT. + cacheSymlinks bool + + // bigWrites if doing multi-page cached writes. + // Negotiated and only set in INIT. + bigWrites bool + + // dontMask if filestestem does not apply umask to creation modes. + // Negotiated in INIT. + dontMask bool } -// NewFUSEConnection creates a FUSE connection to fd -func NewFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRequests uint64) (*Connection, error) { +// newFUSEConnection creates a FUSE connection to fd. +func newFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRequests uint64) (*connection, error) { // Mark the device as ready so it can be used. /dev/fuse can only be used if the FD was used to // mount a FUSE filesystem. fuseFD := fd.Impl().(*DeviceFD) @@ -84,16 +205,41 @@ func NewFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRe fuseFD.fullQueueCh = make(chan struct{}, maxInFlightRequests) fuseFD.writeCursor = 0 - return &Connection{ - fd: fuseFD, + return &connection{ + fd: fuseFD, + maxBackground: fuseDefaultMaxBackground, + congestionThreshold: fuseDefaultCongestionThreshold, + maxPages: fuseDefaultMaxPagesPerReq, + initializedChan: make(chan struct{}), + connected: true, }, nil } +// SetInitialized atomically sets the connection as initialized. +func (conn *connection) SetInitialized() { + // Unblock the requests sent before INIT. + close(conn.initializedChan) + + // Close the channel first to avoid the non-atomic situation + // where conn.initialized is true but there are + // tasks being blocked on the channel. + // And it prevents the newer tasks from gaining + // unnecessary higher chance to be issued before the blocked one. + + atomic.StoreInt32(&(conn.initialized), int32(1)) +} + +// IsInitialized atomically check if the connection is initialized. +// pairs with SetInitialized(). +func (conn *connection) Initialized() bool { + return atomic.LoadInt32(&(conn.initialized)) != 0 +} + // NewRequest creates a new request that can be sent to the FUSE server. -func (conn *Connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { +func (conn *connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { conn.fd.mu.Lock() defer conn.fd.mu.Unlock() - conn.fd.nextOpID += linux.FUSEOpID(ReqIDStep) + conn.fd.nextOpID += linux.FUSEOpID(reqIDStep) hdrLen := (*linux.FUSEHeaderIn)(nil).SizeBytes() hdr := linux.FUSEHeaderIn{ @@ -118,13 +264,49 @@ func (conn *Connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint } // Call makes a request to the server and blocks the invoking task until a -// server responds with a response. -// NOTE: If no task is provided then the Call will simply enqueue the request -// and return a nil response. No blocking will happen in this case. Instead, -// this is used to signify that the processing of this request will happen by -// the kernel.Task that writes the response. See FUSE_INIT for such an -// invocation. -func (conn *Connection) Call(t *kernel.Task, r *Request) (*Response, error) { +// server responds with a response. Task should never be nil. +// Requests will not be sent before the connection is initialized. +// For async tasks, use CallAsync(). +func (conn *connection) Call(t *kernel.Task, r *Request) (*Response, error) { + // Block requests sent before connection is initalized. + if !conn.Initialized() { + if err := t.Block(conn.initializedChan); err != nil { + return nil, err + } + } + + return conn.call(t, r) +} + +// CallAsync makes an async (aka background) request. +// Those requests either do not expect a response (e.g. release) or +// the response should be handled by others (e.g. init). +// Return immediately unless the connection is blocked (before initialization). +// Async call example: init, release, forget, aio, interrupt. +// When the Request is FUSE_INIT, it will not be blocked before initialization. +func (conn *connection) CallAsync(t *kernel.Task, r *Request) error { + // Block requests sent before connection is initalized. + if !conn.Initialized() && r.hdr.Opcode != linux.FUSE_INIT { + if err := t.Block(conn.initializedChan); err != nil { + return err + } + } + + // This should be the only place that invokes call() with a nil task. + _, err := conn.call(nil, r) + return err +} + +// call makes a call without blocking checks. +func (conn *connection) call(t *kernel.Task, r *Request) (*Response, error) { + if !conn.connected { + return nil, syserror.ENOTCONN + } + + if conn.connInitError { + return nil, syserror.ECONNREFUSED + } + fut, err := conn.callFuture(t, r) if err != nil { return nil, err @@ -160,7 +342,7 @@ func (r *Response) UnmarshalPayload(m marshal.Marshallable) error { // callFuture makes a request to the server and returns a future response. // Call resolve() when the response needs to be fulfilled. -func (conn *Connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, error) { +func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, error) { conn.fd.mu.Lock() defer conn.fd.mu.Unlock() @@ -195,7 +377,7 @@ func (conn *Connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, } // callFutureLocked makes a request to the server and returns a future response. -func (conn *Connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) { +func (conn *connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) { conn.fd.queue.PushBack(r) conn.fd.numActiveRequests += 1 fut := newFutureResponse(r.hdr.Opcode) diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go index f3443ac71..2225076bc 100644 --- a/pkg/sentry/fsimpl/fuse/dev.go +++ b/pkg/sentry/fsimpl/fuse/dev.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" @@ -98,7 +99,9 @@ type DeviceFD struct { } // Release implements vfs.FileDescriptionImpl.Release. -func (fd *DeviceFD) Release() {} +func (fd *DeviceFD) Release() { + fd.fs.conn.connected = false +} // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { @@ -124,7 +127,7 @@ func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.R minBuffSize := linux.FUSE_MIN_READ_BUFFER inHdrLen := uint32((*linux.FUSEHeaderIn)(nil).SizeBytes()) writeHdrLen := uint32((*linux.FUSEWriteIn)(nil).SizeBytes()) - negotiatedMinBuffSize := inHdrLen + writeHdrLen + fd.fs.conn.MaxWrite + negotiatedMinBuffSize := inHdrLen + writeHdrLen + fd.fs.conn.maxWrite if minBuffSize < negotiatedMinBuffSize { minBuffSize = negotiatedMinBuffSize } @@ -385,9 +388,9 @@ func (fd *DeviceFD) sendError(ctx context.Context, errno int32, req *Request) er // FUSE_INIT. func (fd *DeviceFD) noReceiverAction(ctx context.Context, r *Response) error { if r.opcode == linux.FUSE_INIT { - // TODO: process init response here. - // Maybe get the creds from the context? - // creds := auth.CredentialsFromContext(ctx) + creds := auth.CredentialsFromContext(ctx) + rootUserNs := kernel.KernelFromContext(ctx).RootUserNamespace() + return fd.fs.conn.InitRecv(r, creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, rootUserNs)) } return nil diff --git a/pkg/sentry/fsimpl/fuse/dev_test.go b/pkg/sentry/fsimpl/fuse/dev_test.go index fcd77832a..122415275 100644 --- a/pkg/sentry/fsimpl/fuse/dev_test.go +++ b/pkg/sentry/fsimpl/fuse/dev_test.go @@ -22,7 +22,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil" - "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -60,25 +59,25 @@ func TestFUSECommunication(t *testing.T) { Name: "SingleClientSingleServer", NumClients: 1, NumServers: 1, - MaxActiveRequests: MaxActiveRequestsDefault, + MaxActiveRequests: maxActiveRequestsDefault, }, { Name: "SingleClientMultipleServers", NumClients: 1, NumServers: 10, - MaxActiveRequests: MaxActiveRequestsDefault, + MaxActiveRequests: maxActiveRequestsDefault, }, { Name: "MultipleClientsSingleServer", NumClients: 10, NumServers: 1, - MaxActiveRequests: MaxActiveRequestsDefault, + MaxActiveRequests: maxActiveRequestsDefault, }, { Name: "MultipleClientsMultipleServers", NumClients: 10, NumServers: 10, - MaxActiveRequests: MaxActiveRequestsDefault, + MaxActiveRequests: maxActiveRequestsDefault, }, { Name: "RequestCapacityFull", @@ -145,7 +144,7 @@ func TestFUSECommunication(t *testing.T) { // CallTest makes a request to the server and blocks the invoking // goroutine until a server responds with a response. Doesn't block // a kernel.Task. Analogous to Connection.Call but used for testing. -func CallTest(conn *Connection, t *kernel.Task, r *Request, i uint32) (*Response, error) { +func CallTest(conn *connection, t *kernel.Task, r *Request, i uint32) (*Response, error) { conn.fd.mu.Lock() // Wait until we're certain that a new request can be processed. @@ -214,7 +213,7 @@ func ReadTest(serverTask *kernel.Task, fd *vfs.FileDescription, inIOseq usermem. // fuseClientRun emulates all the actions of a normal FUSE request. It creates // a header, a payload, calls the server, waits for the response, and processes // the response. -func fuseClientRun(t *testing.T, s *testutil.System, k *kernel.Kernel, conn *Connection, creds *auth.Credentials, pid uint32, inode uint64, clientDone chan struct{}) { +func fuseClientRun(t *testing.T, s *testutil.System, k *kernel.Kernel, conn *connection, creds *auth.Credentials, pid uint32, inode uint64, clientDone chan struct{}) { defer func() { clientDone <- struct{}{} }() tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) @@ -343,7 +342,7 @@ func setup(t *testing.T) *testutil.System { AllowUserMount: true, }) - mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", tmpfs.Name, &vfs.GetFilesystemOptions{}) + mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) if err != nil { t.Fatalf("NewMountNamespace(): %v", err) } @@ -353,7 +352,7 @@ func setup(t *testing.T) *testutil.System { // newTestConnection creates a fuse connection that the sentry can communicate with // and the FD for the server to communicate with. -func newTestConnection(system *testutil.System, k *kernel.Kernel, maxActiveRequests uint64) (*Connection, *vfs.FileDescription, error) { +func newTestConnection(system *testutil.System, k *kernel.Kernel, maxActiveRequests uint64) (*connection, *vfs.FileDescription, error) { vfsObj := &vfs.VirtualFilesystem{} fuseDev := &DeviceFD{} @@ -426,4 +425,4 @@ func (t *testPayload) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) // WriteTo implements io.WriterTo.WriteTo. func (t *testPayload) WriteTo(w io.Writer) (int64, error) { panic("not implemented") -} +}
\ No newline at end of file diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 911b6f7cb..200a93bbf 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -65,7 +65,7 @@ type filesystem struct { // conn is used for communication between the FUSE server // daemon and the sentry fusefs. - conn *Connection + conn *connection // opts is the options the fusefs is initialized with. opts *filesystemOptions @@ -140,7 +140,7 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fsopts.rootMode = rootMode // Set the maxInFlightRequests option. - fsopts.maxActiveRequests = MaxActiveRequestsDefault + fsopts.maxActiveRequests = maxActiveRequestsDefault // Check for unparsed options. if len(mopts) != 0 { @@ -157,8 +157,12 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fs.VFSFilesystem().Init(vfsObj, &fsType, fs) - // TODO: dispatch a FUSE_INIT request to the FUSE daemon server before - // returning. Mount will not block on this dispatched request. + // Send a FUSE_INIT request to the FUSE daemon server before returning. + // This call is not blocking. + if err := fs.conn.InitSend(creds, uint32(kernelTask.ThreadID())); err != nil { + log.Warningf("%s.InitSend: failed with error: %v", fsType.Name(), err) + return nil, nil, err + } // root is the fusefs root directory. root := fs.newInode(creds, fsopts.rootMode) @@ -173,7 +177,7 @@ func NewFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOpt opts: opts, } - conn, err := NewFUSEConnection(ctx, device, opts.maxActiveRequests) + conn, err := newFUSEConnection(ctx, device, opts.maxActiveRequests) if err != nil { log.Warningf("fuse.NewFUSEFilesystem: NewFUSEConnection failed with error: %v", err) return nil, syserror.EINVAL @@ -192,8 +196,8 @@ func (fs *filesystem) Release() { fs.Filesystem.Release() } -// Inode implements kernfs.Inode. -type Inode struct { +// inode implements kernfs.Inode. +type inode struct { kernfs.InodeAttrs kernfs.InodeNoDynamicLookup kernfs.InodeNotSymlink @@ -206,7 +210,7 @@ type Inode struct { } func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *kernfs.Dentry { - i := &Inode{} + i := &inode{} i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) i.dentry.Init(i) @@ -215,7 +219,7 @@ func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *ke } // Open implements kernfs.Inode.Open. -func (i *Inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts) if err != nil { return nil, err diff --git a/pkg/sentry/fsimpl/fuse/init.go b/pkg/sentry/fsimpl/fuse/init.go new file mode 100644 index 000000000..779c2bd3f --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/init.go @@ -0,0 +1,166 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" +) + +// consts used by FUSE_INIT negotiation. +const ( + // fuseMaxMaxPages is the maximum value for MaxPages received in InitOut. + // Follow the same behavior as unix fuse implementation. + fuseMaxMaxPages = 256 + + // Maximum value for the time granularity for file time stamps, 1s. + // Follow the same behavior as unix fuse implementation. + fuseMaxTimeGranNs = 1000000000 + + // Minimum value for MaxWrite. + // Follow the same behavior as unix fuse implementation. + fuseMinMaxWrite = 4096 + + // Temporary default value for max readahead, 128kb. + fuseDefaultMaxReadahead = 131072 + + // The FUSE_INIT_IN flags sent to the daemon. + // TODO(gvisor.dev/issue/3199): complete the flags. + fuseDefaultInitFlags = linux.FUSE_MAX_PAGES +) + +// Adjustable maximums for Connection's cogestion control parameters. +// Used as the upperbound of the config values. +// Currently we do not support adjustment to them. +var ( + MaxUserBackgroundRequest uint16 = fuseDefaultMaxBackground + MaxUserCongestionThreshold uint16 = fuseDefaultCongestionThreshold +) + +// InitSend sends a FUSE_INIT request. +func (conn *connection) InitSend(creds *auth.Credentials, pid uint32) error { + in := linux.FUSEInitIn{ + Major: linux.FUSE_KERNEL_VERSION, + Minor: linux.FUSE_KERNEL_MINOR_VERSION, + // TODO(gvisor.dev/issue/3196): find appropriate way to calculate this + MaxReadahead: fuseDefaultMaxReadahead, + Flags: fuseDefaultInitFlags, + } + + req, err := conn.NewRequest(creds, pid, 0, linux.FUSE_INIT, &in) + if err != nil { + return err + } + + // Since there is no task to block on and FUSE_INIT is the request + // to unblock other requests, use nil. + return conn.CallAsync(nil, req) +} + +// InitRecv receives a FUSE_INIT reply and process it. +func (conn *connection) InitRecv(res *Response, hasSysAdminCap bool) error { + if err := res.Error(); err != nil { + return err + } + + var out linux.FUSEInitOut + if err := res.UnmarshalPayload(&out); err != nil { + return err + } + + return conn.initProcessReply(&out, hasSysAdminCap) +} + +// Process the FUSE_INIT reply from the FUSE server. +func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap bool) error { + // No support for old major fuse versions. + if out.Major != linux.FUSE_KERNEL_VERSION { + conn.connInitError = true + + // Set the connection as initialized and unblock the blocked requests + // (i.e. return error for them). + conn.SetInitialized() + + return nil + } + + // Start processing the reply. + conn.connInitSuccess = true + conn.minor = out.Minor + + // No support for limits before minor version 13. + if out.Minor >= 13 { + conn.bgLock.Lock() + + if out.MaxBackground > 0 { + conn.maxBackground = out.MaxBackground + + if !hasSysAdminCap && + conn.maxBackground > MaxUserBackgroundRequest { + conn.maxBackground = MaxUserBackgroundRequest + } + } + + if out.CongestionThreshold > 0 { + conn.congestionThreshold = out.CongestionThreshold + + if !hasSysAdminCap && + conn.congestionThreshold > MaxUserCongestionThreshold { + conn.congestionThreshold = MaxUserCongestionThreshold + } + } + + conn.bgLock.Unlock() + } + + // No support for the following flags before minor version 6. + if out.Minor >= 6 { + conn.asyncRead = out.Flags&linux.FUSE_ASYNC_READ != 0 + conn.bigWrites = out.Flags&linux.FUSE_BIG_WRITES != 0 + conn.dontMask = out.Flags&linux.FUSE_DONT_MASK != 0 + conn.writebackCache = out.Flags&linux.FUSE_WRITEBACK_CACHE != 0 + conn.cacheSymlinks = out.Flags&linux.FUSE_CACHE_SYMLINKS != 0 + conn.abortErr = out.Flags&linux.FUSE_ABORT_ERROR != 0 + + // TODO(gvisor.dev/issue/3195): figure out how to use TimeGran (0 < TimeGran <= fuseMaxTimeGranNs). + + if out.Flags&linux.FUSE_MAX_PAGES != 0 { + maxPages := out.MaxPages + if maxPages < 1 { + maxPages = 1 + } + if maxPages > fuseMaxMaxPages { + maxPages = fuseMaxMaxPages + } + conn.maxPages = maxPages + } + } + + // No support for negotiating MaxWrite before minor version 5. + if out.Minor >= 5 { + conn.maxWrite = out.MaxWrite + } else { + conn.maxWrite = fuseMinMaxWrite + } + if conn.maxWrite < fuseMinMaxWrite { + conn.maxWrite = fuseMinMaxWrite + } + + // Set connection as initialized and unblock the requests + // issued before init. + conn.SetInitialized() + + return nil +} diff --git a/pkg/syserror/syserror.go b/pkg/syserror/syserror.go index c73072c42..798e07b01 100644 --- a/pkg/syserror/syserror.go +++ b/pkg/syserror/syserror.go @@ -61,6 +61,7 @@ var ( ENOMEM = error(syscall.ENOMEM) ENOSPC = error(syscall.ENOSPC) ENOSYS = error(syscall.ENOSYS) + ENOTCONN = error(syscall.ENOTCONN) ENOTDIR = error(syscall.ENOTDIR) ENOTEMPTY = error(syscall.ENOTEMPTY) ENOTSOCK = error(syscall.ENOTSOCK) |