diff options
Diffstat (limited to 'pkg/sentry/fsimpl/host')
| -rw-r--r-- | pkg/sentry/fsimpl/host/BUILD | 7 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/host/control.go | 2 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/host/host.go | 255 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/host/mmap.go | 133 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/host/save_restore.go | 70 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/host/util.go | 6 |
6 files changed, 222 insertions, 251 deletions
diff --git a/pkg/sentry/fsimpl/host/BUILD b/pkg/sentry/fsimpl/host/BUILD index 56bcf9bdb..4ae9d6d5e 100644 --- a/pkg/sentry/fsimpl/host/BUILD +++ b/pkg/sentry/fsimpl/host/BUILD @@ -8,7 +8,7 @@ go_template_instance( out = "inode_refs.go", package = "host", prefix = "inode", - template = "//pkg/refs_vfs2:refs_template", + template = "//pkg/refsvfs2:refs_template", types = { "T": "inode", }, @@ -19,7 +19,7 @@ go_template_instance( out = "connected_endpoint_refs.go", package = "host", prefix = "ConnectedEndpoint", - template = "//pkg/refs_vfs2:refs_template", + template = "//pkg/refsvfs2:refs_template", types = { "T": "ConnectedEndpoint", }, @@ -33,7 +33,7 @@ go_library( "host.go", "inode_refs.go", "ioctl_unsafe.go", - "mmap.go", + "save_restore.go", "socket.go", "socket_iovec.go", "socket_unsafe.go", @@ -51,6 +51,7 @@ go_library( "//pkg/log", "//pkg/marshal/primitive", "//pkg/refs", + "//pkg/refsvfs2", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/fs/fsutil", diff --git a/pkg/sentry/fsimpl/host/control.go b/pkg/sentry/fsimpl/host/control.go index 0135e4428..13ef48cb5 100644 --- a/pkg/sentry/fsimpl/host/control.go +++ b/pkg/sentry/fsimpl/host/control.go @@ -79,7 +79,7 @@ func fdsToFiles(ctx context.Context, fds []int) []*vfs.FileDescription { } // Create the file backed by hostFD. - file, err := ImportFD(ctx, kernel.KernelFromContext(ctx).HostMount(), fd, false /* isTTY */) + file, err := NewFD(ctx, kernel.KernelFromContext(ctx).HostMount(), fd, &NewFDOptions{}) if err != nil { ctx.Warningf("Error creating file from host FD: %v", err) break diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go index 698e913fe..39b902a3e 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -19,6 +19,7 @@ package host import ( "fmt" "math" + "sync/atomic" "syscall" "golang.org/x/sys/unix" @@ -40,34 +41,97 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) -func newInode(fs *filesystem, hostFD int, fileType linux.FileMode, isTTY bool) (*inode, error) { - // Determine if hostFD is seekable. If not, this syscall will return ESPIPE - // (see fs/read_write.c:llseek), e.g. for pipes, sockets, and some character - // devices. +// inode implements kernfs.Inode. +// +// +stateify savable +type inode struct { + kernfs.InodeNoStatFS + kernfs.InodeNotDirectory + kernfs.InodeNotSymlink + kernfs.CachedMappable + kernfs.InodeTemporary // This holds no meaning as this inode can't be Looked up and is always valid. + + locks vfs.FileLocks + + // When the reference count reaches zero, the host fd is closed. + inodeRefs + + // hostFD contains the host fd that this file was originally created from, + // which must be available at time of restore. + // + // This field is initialized at creation time and is immutable. + hostFD int + + // ino is an inode number unique within this filesystem. + // + // This field is initialized at creation time and is immutable. + ino uint64 + + // ftype is the file's type (a linux.S_IFMT mask). + // + // This field is initialized at creation time and is immutable. + ftype uint16 + + // mayBlock is true if hostFD is non-blocking, and operations on it may + // return EAGAIN or EWOULDBLOCK instead of blocking. + // + // This field is initialized at creation time and is immutable. + mayBlock bool + + // seekable is false if lseek(hostFD) returns ESPIPE. We assume that file + // offsets are meaningful iff seekable is true. + // + // This field is initialized at creation time and is immutable. + seekable bool + + // isTTY is true if this file represents a TTY. + // + // This field is initialized at creation time and is immutable. + isTTY bool + + // savable is true if hostFD may be saved/restored by its numeric value. + // + // This field is initialized at creation time and is immutable. + savable bool + + // Event queue for blocking operations. + queue waiter.Queue + + // If haveBuf is non-zero, hostFD represents a pipe, and buf contains data + // read from the pipe from previous calls to inode.beforeSave(). haveBuf + // and buf are protected by bufMu. haveBuf is accessed using atomic memory + // operations. + bufMu sync.Mutex `state:"nosave"` + haveBuf uint32 + buf []byte +} + +func newInode(ctx context.Context, fs *filesystem, hostFD int, savable bool, fileType linux.FileMode, isTTY bool) (*inode, error) { + // Determine if hostFD is seekable. _, err := unix.Seek(hostFD, 0, linux.SEEK_CUR) seekable := err != syserror.ESPIPE + // We expect regular files to be seekable, as this is required for them to + // be memory-mappable. + if !seekable && fileType == syscall.S_IFREG { + ctx.Infof("host.newInode: host FD %d is a non-seekable regular file", hostFD) + return nil, syserror.ESPIPE + } i := &inode{ - hostFD: hostFD, - ino: fs.NextIno(), - isTTY: isTTY, - wouldBlock: wouldBlock(uint32(fileType)), - seekable: seekable, - // NOTE(b/38213152): Technically, some obscure char devices can be memory - // mapped, but we only allow regular files. - canMap: fileType == linux.S_IFREG, - } - i.pf.inode = i + hostFD: hostFD, + ino: fs.NextIno(), + ftype: uint16(fileType), + mayBlock: fileType != syscall.S_IFREG && fileType != syscall.S_IFDIR, + seekable: seekable, + isTTY: isTTY, + savable: savable, + } + i.CachedMappable.Init(hostFD) i.EnableLeakCheck() - // Non-seekable files can't be memory mapped, assert this. - if !i.seekable && i.canMap { - panic("files that can return EWOULDBLOCK (sockets, pipes, etc.) cannot be memory mapped") - } - - // If the hostFD would block, we must set it to non-blocking and handle - // blocking behavior in the sentry. - if i.wouldBlock { + // If the hostFD can return EWOULDBLOCK when set to non-blocking, do so and + // handle blocking behavior in the sentry. + if i.mayBlock { if err := syscall.SetNonblock(i.hostFD, true); err != nil { return nil, err } @@ -80,6 +144,11 @@ func newInode(fs *filesystem, hostFD int, fileType linux.FileMode, isTTY bool) ( // NewFDOptions contains options to NewFD. type NewFDOptions struct { + // If Savable is true, the host file descriptor may be saved/restored by + // numeric value; the sandbox API requires a corresponding host FD with the + // same numeric value to be provieded at time of restore. + Savable bool + // If IsTTY is true, the file descriptor is a TTY. IsTTY bool @@ -114,7 +183,7 @@ func NewFD(ctx context.Context, mnt *vfs.Mount, hostFD int, opts *NewFDOptions) } d := &kernfs.Dentry{} - i, err := newInode(fs, hostFD, linux.FileMode(s.Mode).FileType(), opts.IsTTY) + i, err := newInode(ctx, fs, hostFD, opts.Savable, linux.FileMode(s.Mode).FileType(), opts.IsTTY) if err != nil { return nil, err } @@ -132,7 +201,8 @@ func NewFD(ctx context.Context, mnt *vfs.Mount, hostFD int, opts *NewFDOptions) // ImportFD sets up and returns a vfs.FileDescription from a donated fd. func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs.FileDescription, error) { return NewFD(ctx, mnt, hostFD, &NewFDOptions{ - IsTTY: isTTY, + Savable: true, + IsTTY: isTTY, }) } @@ -191,68 +261,6 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe return vfs.PrependPathSyntheticError{} } -// inode implements kernfs.Inode. -// -// +stateify savable -type inode struct { - kernfs.InodeNoStatFS - kernfs.InodeNotDirectory - kernfs.InodeNotSymlink - kernfs.InodeTemporary // This holds no meaning as this inode can't be Looked up and is always valid. - - locks vfs.FileLocks - - // When the reference count reaches zero, the host fd is closed. - inodeRefs - - // hostFD contains the host fd that this file was originally created from, - // which must be available at time of restore. - // - // This field is initialized at creation time and is immutable. - hostFD int - - // ino is an inode number unique within this filesystem. - // - // This field is initialized at creation time and is immutable. - ino uint64 - - // isTTY is true if this file represents a TTY. - // - // This field is initialized at creation time and is immutable. - isTTY bool - - // seekable is false if the host fd points to a file representing a stream, - // e.g. a socket or a pipe. Such files are not seekable and can return - // EWOULDBLOCK for I/O operations. - // - // This field is initialized at creation time and is immutable. - seekable bool - - // wouldBlock is true if the host FD would return EWOULDBLOCK for - // operations that would block. - // - // This field is initialized at creation time and is immutable. - wouldBlock bool - - // Event queue for blocking operations. - queue waiter.Queue - - // canMap specifies whether we allow the file to be memory mapped. - // - // This field is initialized at creation time and is immutable. - canMap bool - - // mapsMu protects mappings. - mapsMu sync.Mutex `state:"nosave"` - - // If canMap is true, mappings tracks mappings of hostFD into - // memmap.MappingSpaces. - mappings memmap.MappingSet - - // pf implements platform.File for mappings of hostFD. - pf inodePlatformFile -} - // CheckPermissions implements kernfs.Inode.CheckPermissions. func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error { var s syscall.Stat_t @@ -422,14 +430,7 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre oldpgend, _ := usermem.PageRoundUp(oldSize) newpgend, _ := usermem.PageRoundUp(s.Size) if oldpgend != newpgend { - i.mapsMu.Lock() - i.mappings.Invalidate(memmap.MappableRange{newpgend, oldpgend}, memmap.InvalidateOpts{ - // Compare Linux's mm/truncate.c:truncate_setsize() => - // truncate_pagecache() => - // mm/memory.c:unmap_mapping_range(evencows=1). - InvalidatePrivate: true, - }) - i.mapsMu.Unlock() + i.CachedMappable.InvalidateRange(memmap.MappableRange{newpgend, oldpgend}) } } } @@ -448,7 +449,7 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre // DecRef implements kernfs.Inode.DecRef. func (i *inode) DecRef(ctx context.Context) { i.inodeRefs.DecRef(func() { - if i.wouldBlock { + if i.mayBlock { fdnotifier.RemoveFD(int32(i.hostFD)) } if err := unix.Close(i.hostFD); err != nil { @@ -567,6 +568,13 @@ func (f *fileDescription) Allocate(ctx context.Context, mode, offset, length uin // PRead implements vfs.FileDescriptionImpl.PRead. func (f *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^linux.RWF_HIPRI != 0 { + return 0, syserror.EOPNOTSUPP + } + i := f.inode if !i.seekable { return 0, syserror.ESPIPE @@ -577,19 +585,31 @@ func (f *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, off // Read implements vfs.FileDescriptionImpl.Read. func (f *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^linux.RWF_HIPRI != 0 { + return 0, syserror.EOPNOTSUPP + } + i := f.inode if !i.seekable { + bufN, err := i.readFromBuf(ctx, &dst) + if err != nil { + return bufN, err + } n, err := readFromHostFD(ctx, i.hostFD, dst, -1, opts.Flags) + total := bufN + n if isBlockError(err) { // If we got any data at all, return it as a "completed" partial read // rather than retrying until complete. - if n != 0 { + if total != 0 { err = nil } else { err = syserror.ErrWouldBlock } } - return n, err + return total, err } f.offsetMu.Lock() @@ -599,13 +619,26 @@ func (f *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts return n, err } -func readFromHostFD(ctx context.Context, hostFD int, dst usermem.IOSequence, offset int64, flags uint32) (int64, error) { - // Check that flags are supported. - // - // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. - if flags&^linux.RWF_HIPRI != 0 { - return 0, syserror.EOPNOTSUPP +func (i *inode) readFromBuf(ctx context.Context, dst *usermem.IOSequence) (int64, error) { + if atomic.LoadUint32(&i.haveBuf) == 0 { + return 0, nil + } + i.bufMu.Lock() + defer i.bufMu.Unlock() + if len(i.buf) == 0 { + return 0, nil } + n, err := dst.CopyOut(ctx, i.buf) + *dst = dst.DropFirst(n) + i.buf = i.buf[n:] + if len(i.buf) == 0 { + atomic.StoreUint32(&i.haveBuf, 0) + i.buf = nil + } + return int64(n), err +} + +func readFromHostFD(ctx context.Context, hostFD int, dst usermem.IOSequence, offset int64, flags uint32) (int64, error) { reader := hostfd.GetReadWriterAt(int32(hostFD), offset, flags) n, err := dst.CopyOutFrom(ctx, reader) hostfd.PutReadWriterAt(reader) @@ -735,31 +768,37 @@ func (f *fileDescription) Seek(_ context.Context, offset int64, whence int32) (i } // Sync implements vfs.FileDescriptionImpl.Sync. -func (f *fileDescription) Sync(context.Context) error { +func (f *fileDescription) Sync(ctx context.Context) error { // TODO(gvisor.dev/issue/1897): Currently, we always sync everything. return unix.Fsync(f.inode.hostFD) } // ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. func (f *fileDescription) ConfigureMMap(_ context.Context, opts *memmap.MMapOpts) error { - if !f.inode.canMap { + // NOTE(b/38213152): Technically, some obscure char devices can be memory + // mapped, but we only allow regular files. + if f.inode.ftype != syscall.S_IFREG { return syserror.ENODEV } i := f.inode - i.pf.fileMapperInitOnce.Do(i.pf.fileMapper.Init) + i.CachedMappable.InitFileMapperOnce() return vfs.GenericConfigureMMap(&f.vfsfd, i, opts) } // EventRegister implements waiter.Waitable.EventRegister. func (f *fileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) { f.inode.queue.EventRegister(e, mask) - fdnotifier.UpdateFD(int32(f.inode.hostFD)) + if f.inode.mayBlock { + fdnotifier.UpdateFD(int32(f.inode.hostFD)) + } } // EventUnregister implements waiter.Waitable.EventUnregister. func (f *fileDescription) EventUnregister(e *waiter.Entry) { f.inode.queue.EventUnregister(e) - fdnotifier.UpdateFD(int32(f.inode.hostFD)) + if f.inode.mayBlock { + fdnotifier.UpdateFD(int32(f.inode.hostFD)) + } } // Readiness uses the poll() syscall to check the status of the underlying FD. diff --git a/pkg/sentry/fsimpl/host/mmap.go b/pkg/sentry/fsimpl/host/mmap.go deleted file mode 100644 index b51a17bed..000000000 --- a/pkg/sentry/fsimpl/host/mmap.go +++ /dev/null @@ -1,133 +0,0 @@ -// 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 host - -import ( - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/safemem" - "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" - "gvisor.dev/gvisor/pkg/sentry/memmap" - "gvisor.dev/gvisor/pkg/sync" - "gvisor.dev/gvisor/pkg/usermem" -) - -// inodePlatformFile implements memmap.File. It exists solely because inode -// cannot implement both kernfs.Inode.IncRef and memmap.File.IncRef. -// -// inodePlatformFile should only be used if inode.canMap is true. -// -// +stateify savable -type inodePlatformFile struct { - *inode - - // fdRefsMu protects fdRefs. - fdRefsMu sync.Mutex `state:"nosave"` - - // fdRefs counts references on memmap.File offsets. It is used solely for - // memory accounting. - fdRefs fsutil.FrameRefSet - - // fileMapper caches mappings of the host file represented by this inode. - fileMapper fsutil.HostFileMapper - - // fileMapperInitOnce is used to lazily initialize fileMapper. - fileMapperInitOnce sync.Once `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. -} - -// IncRef implements memmap.File.IncRef. -// -// Precondition: i.inode.canMap must be true. -func (i *inodePlatformFile) IncRef(fr memmap.FileRange) { - i.fdRefsMu.Lock() - i.fdRefs.IncRefAndAccount(fr) - i.fdRefsMu.Unlock() -} - -// DecRef implements memmap.File.DecRef. -// -// Precondition: i.inode.canMap must be true. -func (i *inodePlatformFile) DecRef(fr memmap.FileRange) { - i.fdRefsMu.Lock() - i.fdRefs.DecRefAndAccount(fr) - i.fdRefsMu.Unlock() -} - -// MapInternal implements memmap.File.MapInternal. -// -// Precondition: i.inode.canMap must be true. -func (i *inodePlatformFile) MapInternal(fr memmap.FileRange, at usermem.AccessType) (safemem.BlockSeq, error) { - return i.fileMapper.MapInternal(fr, i.hostFD, at.Write) -} - -// FD implements memmap.File.FD. -func (i *inodePlatformFile) FD() int { - return i.hostFD -} - -// AddMapping implements memmap.Mappable.AddMapping. -// -// Precondition: i.inode.canMap must be true. -func (i *inode) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error { - i.mapsMu.Lock() - mapped := i.mappings.AddMapping(ms, ar, offset, writable) - for _, r := range mapped { - i.pf.fileMapper.IncRefOn(r) - } - i.mapsMu.Unlock() - return nil -} - -// RemoveMapping implements memmap.Mappable.RemoveMapping. -// -// Precondition: i.inode.canMap must be true. -func (i *inode) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) { - i.mapsMu.Lock() - unmapped := i.mappings.RemoveMapping(ms, ar, offset, writable) - for _, r := range unmapped { - i.pf.fileMapper.DecRefOn(r) - } - i.mapsMu.Unlock() -} - -// CopyMapping implements memmap.Mappable.CopyMapping. -// -// Precondition: i.inode.canMap must be true. -func (i *inode) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error { - return i.AddMapping(ctx, ms, dstAR, offset, writable) -} - -// Translate implements memmap.Mappable.Translate. -// -// Precondition: i.inode.canMap must be true. -func (i *inode) Translate(ctx context.Context, required, optional memmap.MappableRange, at usermem.AccessType) ([]memmap.Translation, error) { - mr := optional - return []memmap.Translation{ - { - Source: mr, - File: &i.pf, - Offset: mr.Start, - Perms: usermem.AnyAccess, - }, - }, nil -} - -// InvalidateUnsavable implements memmap.Mappable.InvalidateUnsavable. -// -// Precondition: i.inode.canMap must be true. -func (i *inode) InvalidateUnsavable(ctx context.Context) error { - // We expect the same host fd across save/restore, so all translations - // should be valid. - return nil -} diff --git a/pkg/sentry/fsimpl/host/save_restore.go b/pkg/sentry/fsimpl/host/save_restore.go new file mode 100644 index 000000000..8800652a9 --- /dev/null +++ b/pkg/sentry/fsimpl/host/save_restore.go @@ -0,0 +1,70 @@ +// 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 host + +import ( + "fmt" + "io" + "sync/atomic" + "syscall" + + "gvisor.dev/gvisor/pkg/fdnotifier" + "gvisor.dev/gvisor/pkg/safemem" + "gvisor.dev/gvisor/pkg/sentry/hostfd" + "gvisor.dev/gvisor/pkg/usermem" +) + +// beforeSave is invoked by stateify. +func (i *inode) beforeSave() { + if !i.savable { + panic("host.inode is not savable") + } + if i.ftype == syscall.S_IFIFO { + // If this pipe FD is readable, drain it so that bytes in the pipe can + // be read after restore. (This is a legacy VFS1 feature.) We don't + // know if the pipe FD is readable, so just try reading and tolerate + // EBADF from the read. + i.bufMu.Lock() + defer i.bufMu.Unlock() + var buf [usermem.PageSize]byte + for { + n, err := hostfd.Preadv2(int32(i.hostFD), safemem.BlockSeqOf(safemem.BlockFromSafeSlice(buf[:])), -1 /* offset */, 0 /* flags */) + if n != 0 { + i.buf = append(i.buf, buf[:n]...) + } + if err != nil { + if err == io.EOF || err == syscall.EAGAIN || err == syscall.EBADF { + break + } + panic(fmt.Errorf("host.inode.beforeSave: buffering from pipe failed: %v", err)) + } + } + if len(i.buf) != 0 { + atomic.StoreUint32(&i.haveBuf, 1) + } + } +} + +// afterLoad is invoked by stateify. +func (i *inode) afterLoad() { + if i.mayBlock { + if err := syscall.SetNonblock(i.hostFD, true); err != nil { + panic(fmt.Sprintf("host.inode.afterLoad: failed to set host FD %d non-blocking: %v", i.hostFD, err)) + } + if err := fdnotifier.AddFD(int32(i.hostFD), &i.queue); err != nil { + panic(fmt.Sprintf("host.inode.afterLoad: fdnotifier.AddFD(%d) failed: %v", i.hostFD, err)) + } + } +} diff --git a/pkg/sentry/fsimpl/host/util.go b/pkg/sentry/fsimpl/host/util.go index 412bdb2eb..b2f43a119 100644 --- a/pkg/sentry/fsimpl/host/util.go +++ b/pkg/sentry/fsimpl/host/util.go @@ -43,12 +43,6 @@ func timespecToStatxTimestamp(ts unix.Timespec) linux.StatxTimestamp { return linux.StatxTimestamp{Sec: int64(ts.Sec), Nsec: uint32(ts.Nsec)} } -// wouldBlock returns true for file types that can return EWOULDBLOCK -// for blocking operations, e.g. pipes, character devices, and sockets. -func wouldBlock(fileType uint32) bool { - return fileType == syscall.S_IFIFO || fileType == syscall.S_IFCHR || fileType == syscall.S_IFSOCK -} - // isBlockError checks if an error is EAGAIN or EWOULDBLOCK. // If so, they can be transformed into syserror.ErrWouldBlock. func isBlockError(err error) bool { |