838 lines
24 KiB
Go
838 lines
24 KiB
Go
// Copyright 2019 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 tmpfs
|
|
|
|
import (
|
|
"fmt"
|
|
"sync/atomic"
|
|
|
|
"gvisor.dev/gvisor/pkg/abi/linux"
|
|
"gvisor.dev/gvisor/pkg/context"
|
|
"gvisor.dev/gvisor/pkg/fspath"
|
|
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
|
|
"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
|
|
"gvisor.dev/gvisor/pkg/sentry/vfs"
|
|
"gvisor.dev/gvisor/pkg/syserror"
|
|
"gvisor.dev/gvisor/pkg/usermem"
|
|
)
|
|
|
|
// Sync implements vfs.FilesystemImpl.Sync.
|
|
func (fs *filesystem) Sync(ctx context.Context) error {
|
|
// All filesystem state is in-memory.
|
|
return nil
|
|
}
|
|
|
|
// stepLocked resolves rp.Component() to an existing file, starting from the
|
|
// given directory.
|
|
//
|
|
// stepLocked is loosely analogous to fs/namei.c:walk_component().
|
|
//
|
|
// Preconditions: filesystem.mu must be locked. !rp.Done().
|
|
func stepLocked(rp *vfs.ResolvingPath, d *dentry) (*dentry, error) {
|
|
dir, ok := d.inode.impl.(*directory)
|
|
if !ok {
|
|
return nil, syserror.ENOTDIR
|
|
}
|
|
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
|
|
return nil, err
|
|
}
|
|
afterSymlink:
|
|
name := rp.Component()
|
|
if name == "." {
|
|
rp.Advance()
|
|
return d, nil
|
|
}
|
|
if name == ".." {
|
|
if isRoot, err := rp.CheckRoot(&d.vfsd); err != nil {
|
|
return nil, err
|
|
} else if isRoot || d.parent == nil {
|
|
rp.Advance()
|
|
return d, nil
|
|
}
|
|
if err := rp.CheckMount(&d.parent.vfsd); err != nil {
|
|
return nil, err
|
|
}
|
|
rp.Advance()
|
|
return d.parent, nil
|
|
}
|
|
if len(name) > linux.NAME_MAX {
|
|
return nil, syserror.ENAMETOOLONG
|
|
}
|
|
child, ok := dir.childMap[name]
|
|
if !ok {
|
|
return nil, syserror.ENOENT
|
|
}
|
|
if err := rp.CheckMount(&child.vfsd); err != nil {
|
|
return nil, err
|
|
}
|
|
if symlink, ok := child.inode.impl.(*symlink); ok && rp.ShouldFollowSymlink() {
|
|
// Symlink traversal updates access time.
|
|
atomic.StoreInt64(&d.inode.atime, d.inode.fs.clock.Now().Nanoseconds())
|
|
if err := rp.HandleSymlink(symlink.target); err != nil {
|
|
return nil, err
|
|
}
|
|
goto afterSymlink // don't check the current directory again
|
|
}
|
|
rp.Advance()
|
|
return child, nil
|
|
}
|
|
|
|
// walkParentDirLocked resolves all but the last path component of rp to an
|
|
// existing directory, starting from the given directory (which is usually
|
|
// rp.Start().Impl().(*dentry)). It does not check that the returned directory
|
|
// is searchable by the provider of rp.
|
|
//
|
|
// walkParentDirLocked is loosely analogous to Linux's
|
|
// fs/namei.c:path_parentat().
|
|
//
|
|
// Preconditions: filesystem.mu must be locked. !rp.Done().
|
|
func walkParentDirLocked(rp *vfs.ResolvingPath, d *dentry) (*directory, error) {
|
|
for !rp.Final() {
|
|
next, err := stepLocked(rp, d)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
d = next
|
|
}
|
|
dir, ok := d.inode.impl.(*directory)
|
|
if !ok {
|
|
return nil, syserror.ENOTDIR
|
|
}
|
|
return dir, nil
|
|
}
|
|
|
|
// resolveLocked resolves rp to an existing file.
|
|
//
|
|
// resolveLocked is loosely analogous to Linux's fs/namei.c:path_lookupat().
|
|
//
|
|
// Preconditions: filesystem.mu must be locked.
|
|
func resolveLocked(rp *vfs.ResolvingPath) (*dentry, error) {
|
|
d := rp.Start().Impl().(*dentry)
|
|
for !rp.Done() {
|
|
next, err := stepLocked(rp, d)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
d = next
|
|
}
|
|
if rp.MustBeDir() && !d.inode.isDir() {
|
|
return nil, syserror.ENOTDIR
|
|
}
|
|
return d, nil
|
|
}
|
|
|
|
// doCreateAt checks that creating a file at rp is permitted, then invokes
|
|
// create to do so.
|
|
//
|
|
// doCreateAt is loosely analogous to a conjunction of Linux's
|
|
// fs/namei.c:filename_create() and done_path_create().
|
|
//
|
|
// Preconditions: !rp.Done(). For the final path component in rp,
|
|
// !rp.ShouldFollowSymlink().
|
|
func (fs *filesystem) doCreateAt(rp *vfs.ResolvingPath, dir bool, create func(parentDir *directory, name string) error) error {
|
|
fs.mu.Lock()
|
|
defer fs.mu.Unlock()
|
|
parentDir, err := walkParentDirLocked(rp, rp.Start().Impl().(*dentry))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := parentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
|
|
return err
|
|
}
|
|
name := rp.Component()
|
|
if name == "." || name == ".." {
|
|
return syserror.EEXIST
|
|
}
|
|
if len(name) > linux.NAME_MAX {
|
|
return syserror.ENAMETOOLONG
|
|
}
|
|
if _, ok := parentDir.childMap[name]; ok {
|
|
return syserror.EEXIST
|
|
}
|
|
if !dir && rp.MustBeDir() {
|
|
return syserror.ENOENT
|
|
}
|
|
// tmpfs never calls VFS.InvalidateDentry(), so parentDir.dentry can only
|
|
// be dead if it was deleted.
|
|
if parentDir.dentry.vfsd.IsDead() {
|
|
return syserror.ENOENT
|
|
}
|
|
mnt := rp.Mount()
|
|
if err := mnt.CheckBeginWrite(); err != nil {
|
|
return err
|
|
}
|
|
defer mnt.EndWrite()
|
|
if err := create(parentDir, name); err != nil {
|
|
return err
|
|
}
|
|
|
|
ev := linux.IN_CREATE
|
|
if dir {
|
|
ev |= linux.IN_ISDIR
|
|
}
|
|
parentDir.inode.watches.Notify(name, uint32(ev), 0, vfs.InodeEvent)
|
|
parentDir.inode.touchCMtime()
|
|
return nil
|
|
}
|
|
|
|
// AccessAt implements vfs.Filesystem.Impl.AccessAt.
|
|
func (fs *filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds *auth.Credentials, ats vfs.AccessTypes) error {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return d.inode.checkPermissions(creds, ats)
|
|
}
|
|
|
|
// GetDentryAt implements vfs.FilesystemImpl.GetDentryAt.
|
|
func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetDentryOptions) (*vfs.Dentry, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if opts.CheckSearchable {
|
|
if !d.inode.isDir() {
|
|
return nil, syserror.ENOTDIR
|
|
}
|
|
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
d.IncRef()
|
|
return &d.vfsd, nil
|
|
}
|
|
|
|
// GetParentDentryAt implements vfs.FilesystemImpl.GetParentDentryAt.
|
|
func (fs *filesystem) GetParentDentryAt(ctx context.Context, rp *vfs.ResolvingPath) (*vfs.Dentry, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
dir, err := walkParentDirLocked(rp, rp.Start().Impl().(*dentry))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
dir.dentry.IncRef()
|
|
return &dir.dentry.vfsd, nil
|
|
}
|
|
|
|
// LinkAt implements vfs.FilesystemImpl.LinkAt.
|
|
func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.VirtualDentry) error {
|
|
return fs.doCreateAt(rp, false /* dir */, func(parentDir *directory, name string) error {
|
|
if rp.Mount() != vd.Mount() {
|
|
return syserror.EXDEV
|
|
}
|
|
d := vd.Dentry().Impl().(*dentry)
|
|
if d.inode.isDir() {
|
|
return syserror.EPERM
|
|
}
|
|
if d.inode.nlink == 0 {
|
|
return syserror.ENOENT
|
|
}
|
|
if d.inode.nlink == maxLinks {
|
|
return syserror.EMLINK
|
|
}
|
|
d.inode.incLinksLocked()
|
|
d.inode.watches.Notify("", linux.IN_ATTRIB, 0, vfs.InodeEvent)
|
|
parentDir.insertChildLocked(fs.newDentry(d.inode), name)
|
|
return nil
|
|
})
|
|
}
|
|
|
|
// MkdirAt implements vfs.FilesystemImpl.MkdirAt.
|
|
func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MkdirOptions) error {
|
|
return fs.doCreateAt(rp, true /* dir */, func(parentDir *directory, name string) error {
|
|
creds := rp.Credentials()
|
|
if parentDir.inode.nlink == maxLinks {
|
|
return syserror.EMLINK
|
|
}
|
|
parentDir.inode.incLinksLocked() // from child's ".."
|
|
childDir := fs.newDirectory(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode)
|
|
parentDir.insertChildLocked(&childDir.dentry, name)
|
|
return nil
|
|
})
|
|
}
|
|
|
|
// MknodAt implements vfs.FilesystemImpl.MknodAt.
|
|
func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.MknodOptions) error {
|
|
return fs.doCreateAt(rp, false /* dir */, func(parentDir *directory, name string) error {
|
|
creds := rp.Credentials()
|
|
var childInode *inode
|
|
switch opts.Mode.FileType() {
|
|
case 0, linux.S_IFREG:
|
|
childInode = fs.newRegularFile(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode)
|
|
case linux.S_IFIFO:
|
|
childInode = fs.newNamedPipe(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode)
|
|
case linux.S_IFBLK:
|
|
childInode = fs.newDeviceFile(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode, vfs.BlockDevice, opts.DevMajor, opts.DevMinor)
|
|
case linux.S_IFCHR:
|
|
childInode = fs.newDeviceFile(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode, vfs.CharDevice, opts.DevMajor, opts.DevMinor)
|
|
case linux.S_IFSOCK:
|
|
childInode = fs.newSocketFile(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode, opts.Endpoint)
|
|
default:
|
|
return syserror.EINVAL
|
|
}
|
|
child := fs.newDentry(childInode)
|
|
parentDir.insertChildLocked(child, name)
|
|
return nil
|
|
})
|
|
}
|
|
|
|
// OpenAt implements vfs.FilesystemImpl.OpenAt.
|
|
func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
|
|
if opts.Flags&linux.O_TMPFILE != 0 {
|
|
// Not yet supported.
|
|
return nil, syserror.EOPNOTSUPP
|
|
}
|
|
|
|
// Handle O_CREAT and !O_CREAT separately, since in the latter case we
|
|
// don't need fs.mu for writing.
|
|
if opts.Flags&linux.O_CREAT == 0 {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return d.open(ctx, rp, &opts, false /* afterCreate */)
|
|
}
|
|
|
|
mustCreate := opts.Flags&linux.O_EXCL != 0
|
|
start := rp.Start().Impl().(*dentry)
|
|
fs.mu.Lock()
|
|
defer fs.mu.Unlock()
|
|
if rp.Done() {
|
|
// Reject attempts to open directories with O_CREAT.
|
|
if rp.MustBeDir() {
|
|
return nil, syserror.EISDIR
|
|
}
|
|
if mustCreate {
|
|
return nil, syserror.EEXIST
|
|
}
|
|
return start.open(ctx, rp, &opts, false /* afterCreate */)
|
|
}
|
|
afterTrailingSymlink:
|
|
parentDir, err := walkParentDirLocked(rp, start)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// Check for search permission in the parent directory.
|
|
if err := parentDir.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
|
|
return nil, err
|
|
}
|
|
// Reject attempts to open directories with O_CREAT.
|
|
if rp.MustBeDir() {
|
|
return nil, syserror.EISDIR
|
|
}
|
|
name := rp.Component()
|
|
if name == "." || name == ".." {
|
|
return nil, syserror.EISDIR
|
|
}
|
|
if len(name) > linux.NAME_MAX {
|
|
return nil, syserror.ENAMETOOLONG
|
|
}
|
|
// Determine whether or not we need to create a file.
|
|
child, ok := parentDir.childMap[name]
|
|
if !ok {
|
|
// Already checked for searchability above; now check for writability.
|
|
if err := parentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
|
|
return nil, err
|
|
}
|
|
if err := rp.Mount().CheckBeginWrite(); err != nil {
|
|
return nil, err
|
|
}
|
|
defer rp.Mount().EndWrite()
|
|
// Create and open the child.
|
|
creds := rp.Credentials()
|
|
child := fs.newDentry(fs.newRegularFile(creds.EffectiveKUID, creds.EffectiveKGID, opts.Mode))
|
|
parentDir.insertChildLocked(child, name)
|
|
fd, err := child.open(ctx, rp, &opts, true)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
parentDir.inode.watches.Notify(name, linux.IN_CREATE, 0, vfs.PathEvent)
|
|
parentDir.inode.touchCMtime()
|
|
return fd, nil
|
|
}
|
|
// Is the file mounted over?
|
|
if err := rp.CheckMount(&child.vfsd); err != nil {
|
|
return nil, err
|
|
}
|
|
// Do we need to resolve a trailing symlink?
|
|
if symlink, ok := child.inode.impl.(*symlink); ok && rp.ShouldFollowSymlink() {
|
|
// Symlink traversal updates access time.
|
|
atomic.StoreInt64(&child.inode.atime, child.inode.fs.clock.Now().Nanoseconds())
|
|
if err := rp.HandleSymlink(symlink.target); err != nil {
|
|
return nil, err
|
|
}
|
|
start = &parentDir.dentry
|
|
goto afterTrailingSymlink
|
|
}
|
|
// Open existing file.
|
|
if mustCreate {
|
|
return nil, syserror.EEXIST
|
|
}
|
|
return child.open(ctx, rp, &opts, false)
|
|
}
|
|
|
|
func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions, afterCreate bool) (*vfs.FileDescription, error) {
|
|
ats := vfs.AccessTypesForOpenFlags(opts)
|
|
if !afterCreate {
|
|
if err := d.inode.checkPermissions(rp.Credentials(), ats); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
switch impl := d.inode.impl.(type) {
|
|
case *regularFile:
|
|
var fd regularFileFD
|
|
fd.LockFD.Init(&d.inode.locks)
|
|
if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil {
|
|
return nil, err
|
|
}
|
|
if opts.Flags&linux.O_TRUNC != 0 {
|
|
if _, err := impl.truncate(0); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return &fd.vfsfd, nil
|
|
case *directory:
|
|
// Can't open directories writably.
|
|
if ats&vfs.MayWrite != 0 {
|
|
return nil, syserror.EISDIR
|
|
}
|
|
var fd directoryFD
|
|
fd.LockFD.Init(&d.inode.locks)
|
|
if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil {
|
|
return nil, err
|
|
}
|
|
return &fd.vfsfd, nil
|
|
case *symlink:
|
|
// TODO(gvisor.dev/issue/2782): Can't open symlinks without O_PATH.
|
|
return nil, syserror.ELOOP
|
|
case *namedPipe:
|
|
return impl.pipe.Open(ctx, rp.Mount(), &d.vfsd, opts.Flags, &d.inode.locks)
|
|
case *deviceFile:
|
|
return rp.VirtualFilesystem().OpenDeviceSpecialFile(ctx, rp.Mount(), &d.vfsd, impl.kind, impl.major, impl.minor, opts)
|
|
case *socketFile:
|
|
return nil, syserror.ENXIO
|
|
default:
|
|
panic(fmt.Sprintf("unknown inode type: %T", d.inode.impl))
|
|
}
|
|
}
|
|
|
|
// ReadlinkAt implements vfs.FilesystemImpl.ReadlinkAt.
|
|
func (fs *filesystem) ReadlinkAt(ctx context.Context, rp *vfs.ResolvingPath) (string, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
symlink, ok := d.inode.impl.(*symlink)
|
|
if !ok {
|
|
return "", syserror.EINVAL
|
|
}
|
|
symlink.inode.touchAtime(rp.Mount())
|
|
return symlink.target, nil
|
|
}
|
|
|
|
// RenameAt implements vfs.FilesystemImpl.RenameAt.
|
|
func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldParentVD vfs.VirtualDentry, oldName string, opts vfs.RenameOptions) error {
|
|
if opts.Flags != 0 {
|
|
// TODO(b/145974740): Support renameat2 flags.
|
|
return syserror.EINVAL
|
|
}
|
|
|
|
// Resolve newParent first to verify that it's on this Mount.
|
|
fs.mu.Lock()
|
|
defer fs.mu.Unlock()
|
|
newParentDir, err := walkParentDirLocked(rp, rp.Start().Impl().(*dentry))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
newName := rp.Component()
|
|
if newName == "." || newName == ".." {
|
|
return syserror.EBUSY
|
|
}
|
|
mnt := rp.Mount()
|
|
if mnt != oldParentVD.Mount() {
|
|
return syserror.EXDEV
|
|
}
|
|
if err := mnt.CheckBeginWrite(); err != nil {
|
|
return err
|
|
}
|
|
defer mnt.EndWrite()
|
|
|
|
oldParentDir := oldParentVD.Dentry().Impl().(*dentry).inode.impl.(*directory)
|
|
if err := oldParentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
|
|
return err
|
|
}
|
|
renamed, ok := oldParentDir.childMap[oldName]
|
|
if !ok {
|
|
return syserror.ENOENT
|
|
}
|
|
// Note that we don't need to call rp.CheckMount(), since if renamed is a
|
|
// mount point then we want to rename the mount point, not anything in the
|
|
// mounted filesystem.
|
|
if renamed.inode.isDir() {
|
|
if renamed == &newParentDir.dentry || genericIsAncestorDentry(renamed, &newParentDir.dentry) {
|
|
return syserror.EINVAL
|
|
}
|
|
if oldParentDir != newParentDir {
|
|
// Writability is needed to change renamed's "..".
|
|
if err := renamed.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
} else {
|
|
if opts.MustBeDir || rp.MustBeDir() {
|
|
return syserror.ENOTDIR
|
|
}
|
|
}
|
|
|
|
if err := newParentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
|
|
return err
|
|
}
|
|
replaced, ok := newParentDir.childMap[newName]
|
|
if ok {
|
|
replacedDir, ok := replaced.inode.impl.(*directory)
|
|
if ok {
|
|
if !renamed.inode.isDir() {
|
|
return syserror.EISDIR
|
|
}
|
|
if len(replacedDir.childMap) != 0 {
|
|
return syserror.ENOTEMPTY
|
|
}
|
|
} else {
|
|
if rp.MustBeDir() {
|
|
return syserror.ENOTDIR
|
|
}
|
|
if renamed.inode.isDir() {
|
|
return syserror.ENOTDIR
|
|
}
|
|
}
|
|
} else {
|
|
if renamed.inode.isDir() && newParentDir.inode.nlink == maxLinks {
|
|
return syserror.EMLINK
|
|
}
|
|
}
|
|
// tmpfs never calls VFS.InvalidateDentry(), so newParentDir.dentry can
|
|
// only be dead if it was deleted.
|
|
if newParentDir.dentry.vfsd.IsDead() {
|
|
return syserror.ENOENT
|
|
}
|
|
|
|
// Linux places this check before some of those above; we do it here for
|
|
// simplicity, under the assumption that applications are not intentionally
|
|
// doing noop renames expecting them to succeed where non-noop renames
|
|
// would fail.
|
|
if renamed == replaced {
|
|
return nil
|
|
}
|
|
vfsObj := rp.VirtualFilesystem()
|
|
mntns := vfs.MountNamespaceFromContext(ctx)
|
|
defer mntns.DecRef()
|
|
var replacedVFSD *vfs.Dentry
|
|
if replaced != nil {
|
|
replacedVFSD = &replaced.vfsd
|
|
}
|
|
if err := vfsObj.PrepareRenameDentry(mntns, &renamed.vfsd, replacedVFSD); err != nil {
|
|
return err
|
|
}
|
|
if replaced != nil {
|
|
newParentDir.removeChildLocked(replaced)
|
|
if replaced.inode.isDir() {
|
|
newParentDir.inode.decLinksLocked() // from replaced's ".."
|
|
}
|
|
replaced.inode.decLinksLocked()
|
|
}
|
|
oldParentDir.removeChildLocked(renamed)
|
|
newParentDir.insertChildLocked(renamed, newName)
|
|
vfsObj.CommitRenameReplaceDentry(&renamed.vfsd, replacedVFSD)
|
|
oldParentDir.inode.touchCMtime()
|
|
if oldParentDir != newParentDir {
|
|
if renamed.inode.isDir() {
|
|
oldParentDir.inode.decLinksLocked()
|
|
newParentDir.inode.incLinksLocked()
|
|
}
|
|
newParentDir.inode.touchCMtime()
|
|
}
|
|
renamed.inode.touchCtime()
|
|
|
|
vfs.InotifyRename(ctx, &renamed.inode.watches, &oldParentDir.inode.watches, &newParentDir.inode.watches, oldName, newName, renamed.inode.isDir())
|
|
return nil
|
|
}
|
|
|
|
// RmdirAt implements vfs.FilesystemImpl.RmdirAt.
|
|
func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error {
|
|
fs.mu.Lock()
|
|
defer fs.mu.Unlock()
|
|
parentDir, err := walkParentDirLocked(rp, rp.Start().Impl().(*dentry))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := parentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
|
|
return err
|
|
}
|
|
name := rp.Component()
|
|
if name == "." {
|
|
return syserror.EINVAL
|
|
}
|
|
if name == ".." {
|
|
return syserror.ENOTEMPTY
|
|
}
|
|
child, ok := parentDir.childMap[name]
|
|
if !ok {
|
|
return syserror.ENOENT
|
|
}
|
|
childDir, ok := child.inode.impl.(*directory)
|
|
if !ok {
|
|
return syserror.ENOTDIR
|
|
}
|
|
if len(childDir.childMap) != 0 {
|
|
return syserror.ENOTEMPTY
|
|
}
|
|
mnt := rp.Mount()
|
|
if err := mnt.CheckBeginWrite(); err != nil {
|
|
return err
|
|
}
|
|
defer mnt.EndWrite()
|
|
vfsObj := rp.VirtualFilesystem()
|
|
mntns := vfs.MountNamespaceFromContext(ctx)
|
|
defer mntns.DecRef()
|
|
if err := vfsObj.PrepareDeleteDentry(mntns, &child.vfsd); err != nil {
|
|
return err
|
|
}
|
|
parentDir.removeChildLocked(child)
|
|
parentDir.inode.watches.Notify(name, linux.IN_DELETE|linux.IN_ISDIR, 0, vfs.InodeEvent)
|
|
// Remove links for child, child/., and child/..
|
|
child.inode.decLinksLocked()
|
|
child.inode.decLinksLocked()
|
|
parentDir.inode.decLinksLocked()
|
|
vfsObj.CommitDeleteDentry(&child.vfsd)
|
|
parentDir.inode.touchCMtime()
|
|
return nil
|
|
}
|
|
|
|
// SetStatAt implements vfs.FilesystemImpl.SetStatAt.
|
|
func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := d.inode.setStat(ctx, rp.Credentials(), &opts.Stat); err != nil {
|
|
return err
|
|
}
|
|
|
|
if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 {
|
|
d.InotifyWithParent(ev, 0, vfs.InodeEvent)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// StatAt implements vfs.FilesystemImpl.StatAt.
|
|
func (fs *filesystem) StatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.StatOptions) (linux.Statx, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return linux.Statx{}, err
|
|
}
|
|
var stat linux.Statx
|
|
d.inode.statTo(&stat)
|
|
return stat, nil
|
|
}
|
|
|
|
// StatFSAt implements vfs.FilesystemImpl.StatFSAt.
|
|
func (fs *filesystem) StatFSAt(ctx context.Context, rp *vfs.ResolvingPath) (linux.Statfs, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
if _, err := resolveLocked(rp); err != nil {
|
|
return linux.Statfs{}, err
|
|
}
|
|
statfs := linux.Statfs{
|
|
Type: linux.TMPFS_MAGIC,
|
|
BlockSize: usermem.PageSize,
|
|
FragmentSize: usermem.PageSize,
|
|
NameLength: linux.NAME_MAX,
|
|
// TODO(b/29637826): Allow configuring a tmpfs size and enforce it.
|
|
Blocks: 0,
|
|
BlocksFree: 0,
|
|
}
|
|
return statfs, nil
|
|
}
|
|
|
|
// SymlinkAt implements vfs.FilesystemImpl.SymlinkAt.
|
|
func (fs *filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, target string) error {
|
|
return fs.doCreateAt(rp, false /* dir */, func(parentDir *directory, name string) error {
|
|
creds := rp.Credentials()
|
|
child := fs.newDentry(fs.newSymlink(creds.EffectiveKUID, creds.EffectiveKGID, 0777, target))
|
|
parentDir.insertChildLocked(child, name)
|
|
return nil
|
|
})
|
|
}
|
|
|
|
// UnlinkAt implements vfs.FilesystemImpl.UnlinkAt.
|
|
func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error {
|
|
fs.mu.Lock()
|
|
defer fs.mu.Unlock()
|
|
parentDir, err := walkParentDirLocked(rp, rp.Start().Impl().(*dentry))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := parentDir.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
|
|
return err
|
|
}
|
|
name := rp.Component()
|
|
if name == "." || name == ".." {
|
|
return syserror.EISDIR
|
|
}
|
|
child, ok := parentDir.childMap[name]
|
|
if !ok {
|
|
return syserror.ENOENT
|
|
}
|
|
if child.inode.isDir() {
|
|
return syserror.EISDIR
|
|
}
|
|
if rp.MustBeDir() {
|
|
return syserror.ENOTDIR
|
|
}
|
|
mnt := rp.Mount()
|
|
if err := mnt.CheckBeginWrite(); err != nil {
|
|
return err
|
|
}
|
|
defer mnt.EndWrite()
|
|
vfsObj := rp.VirtualFilesystem()
|
|
mntns := vfs.MountNamespaceFromContext(ctx)
|
|
defer mntns.DecRef()
|
|
if err := vfsObj.PrepareDeleteDentry(mntns, &child.vfsd); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Generate inotify events. Note that this must take place before the link
|
|
// count of the child is decremented, or else the watches may be dropped
|
|
// before these events are added.
|
|
vfs.InotifyRemoveChild(&child.inode.watches, &parentDir.inode.watches, name)
|
|
|
|
parentDir.removeChildLocked(child)
|
|
child.inode.decLinksLocked()
|
|
vfsObj.CommitDeleteDentry(&child.vfsd)
|
|
parentDir.inode.touchCMtime()
|
|
return nil
|
|
}
|
|
|
|
// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt.
|
|
func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
|
|
return nil, err
|
|
}
|
|
switch impl := d.inode.impl.(type) {
|
|
case *socketFile:
|
|
return impl.ep, nil
|
|
default:
|
|
return nil, syserror.ECONNREFUSED
|
|
}
|
|
}
|
|
|
|
// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt.
|
|
func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return d.inode.listxattr(size)
|
|
}
|
|
|
|
// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt.
|
|
func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
return d.inode.getxattr(rp.Credentials(), &opts)
|
|
}
|
|
|
|
// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt.
|
|
func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := d.inode.setxattr(rp.Credentials(), &opts); err != nil {
|
|
return err
|
|
}
|
|
|
|
d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
|
|
return nil
|
|
}
|
|
|
|
// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt.
|
|
func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
d, err := resolveLocked(rp)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := d.inode.removexattr(rp.Credentials(), name); err != nil {
|
|
return err
|
|
}
|
|
|
|
d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
|
|
return nil
|
|
}
|
|
|
|
// PrependPath implements vfs.FilesystemImpl.PrependPath.
|
|
func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDentry, b *fspath.Builder) error {
|
|
fs.mu.RLock()
|
|
defer fs.mu.RUnlock()
|
|
mnt := vd.Mount()
|
|
d := vd.Dentry().Impl().(*dentry)
|
|
for {
|
|
if mnt == vfsroot.Mount() && &d.vfsd == vfsroot.Dentry() {
|
|
return vfs.PrependPathAtVFSRootError{}
|
|
}
|
|
if &d.vfsd == mnt.Root() {
|
|
return nil
|
|
}
|
|
if d.parent == nil {
|
|
if d.name != "" {
|
|
// This must be an anonymous memfd file.
|
|
b.PrependComponent("/" + d.name)
|
|
return vfs.PrependPathSyntheticError{}
|
|
}
|
|
return vfs.PrependPathAtNonMountRootError{}
|
|
}
|
|
b.PrependComponent(d.name)
|
|
d = d.parent
|
|
}
|
|
}
|