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-rw-r--r--pkg/sentry/fsimpl/devpts/slave.go2
-rw-r--r--pkg/sentry/fsimpl/fuse/BUILD4
-rw-r--r--pkg/sentry/fsimpl/fuse/dev.go28
-rw-r--r--pkg/sentry/fsimpl/fuse/fusefs.go200
-rw-r--r--pkg/sentry/fsimpl/gofer/filesystem.go19
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go29
-rw-r--r--pkg/sentry/fsimpl/gofer/regular_file.go41
-rw-r--r--pkg/sentry/fsimpl/gofer/special_file.go56
-rw-r--r--pkg/sentry/fsimpl/host/host.go7
-rw-r--r--pkg/sentry/fsimpl/kernfs/fd_impl_util.go6
-rw-r--r--pkg/sentry/fsimpl/kernfs/inode_impl_util.go2
-rw-r--r--pkg/sentry/fsimpl/overlay/filesystem.go2
-rw-r--r--pkg/sentry/fsimpl/overlay/non_directory.go4
-rw-r--r--pkg/sentry/fsimpl/proc/subtasks.go2
-rw-r--r--pkg/sentry/fsimpl/tmpfs/filesystem.go2
-rw-r--r--pkg/sentry/fsimpl/tmpfs/regular_file.go35
-rw-r--r--pkg/sentry/fsimpl/tmpfs/tmpfs.go7
17 files changed, 391 insertions, 55 deletions
diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go
index 2018b978a..a91cae3ef 100644
--- a/pkg/sentry/fsimpl/devpts/slave.go
+++ b/pkg/sentry/fsimpl/devpts/slave.go
@@ -132,7 +132,7 @@ func (sfd *slaveFileDescription) Write(ctx context.Context, src usermem.IOSequen
return sfd.inode.t.ld.outputQueueWrite(ctx, src)
}
-// Ioctl implements vfs.FileDescripionImpl.Ioctl.
+// Ioctl implements vfs.FileDescriptionImpl.Ioctl.
func (sfd *slaveFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
switch cmd := args[1].Uint(); cmd {
case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ
diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD
index 3e00c2abb..737007748 100644
--- a/pkg/sentry/fsimpl/fuse/BUILD
+++ b/pkg/sentry/fsimpl/fuse/BUILD
@@ -6,13 +6,17 @@ go_library(
name = "fuse",
srcs = [
"dev.go",
+ "fusefs.go",
],
visibility = ["//pkg/sentry:internal"],
deps = [
"//pkg/abi/linux",
"//pkg/context",
+ "//pkg/log",
"//pkg/sentry/fsimpl/devtmpfs",
+ "//pkg/sentry/fsimpl/kernfs",
"//pkg/sentry/kernel",
+ "//pkg/sentry/kernel/auth",
"//pkg/sentry/vfs",
"//pkg/syserror",
"//pkg/usermem",
diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go
index dc33268af..c9e12a94f 100644
--- a/pkg/sentry/fsimpl/fuse/dev.go
+++ b/pkg/sentry/fsimpl/fuse/dev.go
@@ -51,6 +51,9 @@ type DeviceFD struct {
vfs.DentryMetadataFileDescriptionImpl
vfs.NoLockFD
+ // mounted specifies whether a FUSE filesystem was mounted using the DeviceFD.
+ mounted bool
+
// TODO(gvisor.dev/issue/2987): Add all the data structures needed to enqueue
// and deque requests, control synchronization and establish communication
// between the FUSE kernel module and the /dev/fuse character device.
@@ -61,26 +64,51 @@ func (fd *DeviceFD) Release() {}
// PRead implements vfs.FileDescriptionImpl.PRead.
func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
+ // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
+ if !fd.mounted {
+ return 0, syserror.EPERM
+ }
+
return 0, syserror.ENOSYS
}
// Read implements vfs.FileDescriptionImpl.Read.
func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+ // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
+ if !fd.mounted {
+ return 0, syserror.EPERM
+ }
+
return 0, syserror.ENOSYS
}
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *DeviceFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
+ if !fd.mounted {
+ return 0, syserror.EPERM
+ }
+
return 0, syserror.ENOSYS
}
// Write implements vfs.FileDescriptionImpl.Write.
func (fd *DeviceFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
+ // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
+ if !fd.mounted {
+ return 0, syserror.EPERM
+ }
+
return 0, syserror.ENOSYS
}
// Seek implements vfs.FileDescriptionImpl.Seek.
func (fd *DeviceFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
+ // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
+ if !fd.mounted {
+ return 0, syserror.EPERM
+ }
+
return 0, syserror.ENOSYS
}
diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go
new file mode 100644
index 000000000..f7775fb9b
--- /dev/null
+++ b/pkg/sentry/fsimpl/fuse/fusefs.go
@@ -0,0 +1,200 @@
+// 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 implements fusefs.
+package fuse
+
+import (
+ "strconv"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/log"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Name is the default filesystem name.
+const Name = "fuse"
+
+// FilesystemType implements vfs.FilesystemType.
+type FilesystemType struct{}
+
+type filesystemOptions struct {
+ // userID specifies the numeric uid of the mount owner.
+ // This option should not be specified by the filesystem owner.
+ // It is set by libfuse (or, if libfuse is not used, must be set
+ // by the filesystem itself). For more information, see man page
+ // for fuse(8)
+ userID uint32
+
+ // groupID specifies the numeric gid of the mount owner.
+ // This option should not be specified by the filesystem owner.
+ // It is set by libfuse (or, if libfuse is not used, must be set
+ // by the filesystem itself). For more information, see man page
+ // for fuse(8)
+ groupID uint32
+
+ // rootMode specifies the the file mode of the filesystem's root.
+ rootMode linux.FileMode
+}
+
+// filesystem implements vfs.FilesystemImpl.
+type filesystem struct {
+ kernfs.Filesystem
+ devMinor uint32
+
+ // fuseFD is the FD returned when opening /dev/fuse. It is used for communication
+ // between the FUSE server daemon and the sentry fusefs.
+ fuseFD *DeviceFD
+
+ // opts is the options the fusefs is initialized with.
+ opts filesystemOptions
+}
+
+// Name implements vfs.FilesystemType.Name.
+func (FilesystemType) Name() string {
+ return Name
+}
+
+// GetFilesystem implements vfs.FilesystemType.GetFilesystem.
+func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
+ devMinor, err := vfsObj.GetAnonBlockDevMinor()
+ if err != nil {
+ return nil, nil, err
+ }
+
+ var fsopts filesystemOptions
+ mopts := vfs.GenericParseMountOptions(opts.Data)
+ deviceDescriptorStr, ok := mopts["fd"]
+ if !ok {
+ log.Warningf("%s.GetFilesystem: communication file descriptor N (obtained by opening /dev/fuse) must be specified as 'fd=N'", fsType.Name())
+ return nil, nil, syserror.EINVAL
+ }
+ delete(mopts, "fd")
+
+ deviceDescriptor, err := strconv.ParseInt(deviceDescriptorStr, 10 /* base */, 32 /* bitSize */)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ kernelTask := kernel.TaskFromContext(ctx)
+ if kernelTask == nil {
+ log.Warningf("%s.GetFilesystem: couldn't get kernel task from context", fsType.Name())
+ return nil, nil, syserror.EINVAL
+ }
+ fuseFd := kernelTask.GetFileVFS2(int32(deviceDescriptor))
+
+ // Parse and set all the other supported FUSE mount options.
+ // TODO: Expand the supported mount options.
+ if userIDStr, ok := mopts["user_id"]; ok {
+ delete(mopts, "user_id")
+ userID, err := strconv.ParseUint(userIDStr, 10, 32)
+ if err != nil {
+ log.Warningf("%s.GetFilesystem: invalid user_id: user_id=%s", fsType.Name(), userIDStr)
+ return nil, nil, syserror.EINVAL
+ }
+ fsopts.userID = uint32(userID)
+ }
+
+ if groupIDStr, ok := mopts["group_id"]; ok {
+ delete(mopts, "group_id")
+ groupID, err := strconv.ParseUint(groupIDStr, 10, 32)
+ if err != nil {
+ log.Warningf("%s.GetFilesystem: invalid group_id: group_id=%s", fsType.Name(), groupIDStr)
+ return nil, nil, syserror.EINVAL
+ }
+ fsopts.groupID = uint32(groupID)
+ }
+
+ rootMode := linux.FileMode(0777)
+ modeStr, ok := mopts["rootmode"]
+ if ok {
+ delete(mopts, "rootmode")
+ mode, err := strconv.ParseUint(modeStr, 8, 32)
+ if err != nil {
+ log.Warningf("%s.GetFilesystem: invalid mode: %q", fsType.Name(), modeStr)
+ return nil, nil, syserror.EINVAL
+ }
+ rootMode = linux.FileMode(mode)
+ }
+ fsopts.rootMode = rootMode
+
+ // Check for unparsed options.
+ if len(mopts) != 0 {
+ log.Warningf("%s.GetFilesystem: unknown options: %v", fsType.Name(), mopts)
+ return nil, nil, syserror.EINVAL
+ }
+
+ // 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 := fuseFd.Impl().(*DeviceFD)
+ fuseFD.mounted = true
+
+ fs := &filesystem{
+ devMinor: devMinor,
+ fuseFD: fuseFD,
+ opts: fsopts,
+ }
+
+ 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.
+
+ // root is the fusefs root directory.
+ root := fs.newInode(creds, fsopts.rootMode)
+
+ return fs.VFSFilesystem(), root.VFSDentry(), nil
+}
+
+// Release implements vfs.FilesystemImpl.Release.
+func (fs *filesystem) Release() {
+ fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
+ fs.Filesystem.Release()
+}
+
+// Inode implements kernfs.Inode.
+type Inode struct {
+ kernfs.InodeAttrs
+ kernfs.InodeNoDynamicLookup
+ kernfs.InodeNotSymlink
+ kernfs.InodeDirectoryNoNewChildren
+ kernfs.OrderedChildren
+
+ locks vfs.FileLocks
+
+ dentry kernfs.Dentry
+}
+
+func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *kernfs.Dentry {
+ 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)
+
+ return &i.dentry
+}
+
+// Open implements kernfs.Inode.Open.
+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
+ }
+ return fd.VFSFileDescription(), nil
+}
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index cd5f5049e..00e3c99cd 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -150,11 +150,9 @@ afterSymlink:
return nil, err
}
if d != d.parent && !d.cachedMetadataAuthoritative() {
- _, attrMask, attr, err := d.parent.file.getAttr(ctx, dentryAttrMask())
- if err != nil {
+ if err := d.parent.updateFromGetattr(ctx); err != nil {
return nil, err
}
- d.parent.updateFromP9Attrs(attrMask, &attr)
}
rp.Advance()
return d.parent, nil
@@ -209,17 +207,28 @@ func (fs *filesystem) getChildLocked(ctx context.Context, vfsObj *vfs.VirtualFil
// Preconditions: As for getChildLocked. !parent.isSynthetic().
func (fs *filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.VirtualFilesystem, parent *dentry, name string, child *dentry, ds **[]*dentry) (*dentry, error) {
+ if child != nil {
+ // Need to lock child.metadataMu because we might be updating child
+ // metadata. We need to hold the lock *before* getting metadata from the
+ // server and release it after updating local metadata.
+ child.metadataMu.Lock()
+ }
qid, file, attrMask, attr, err := parent.file.walkGetAttrOne(ctx, name)
if err != nil && err != syserror.ENOENT {
+ if child != nil {
+ child.metadataMu.Unlock()
+ }
return nil, err
}
if child != nil {
if !file.isNil() && inoFromPath(qid.Path) == child.ino {
// The file at this path hasn't changed. Just update cached metadata.
file.close(ctx)
- child.updateFromP9Attrs(attrMask, &attr)
+ child.updateFromP9AttrsLocked(attrMask, &attr)
+ child.metadataMu.Unlock()
return child, nil
}
+ child.metadataMu.Unlock()
if file.isNil() && child.isSynthetic() {
// We have a synthetic file, and no remote file has arisen to
// replace it.
@@ -1325,7 +1334,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts
fs.renameMuRUnlockAndCheckCaching(&ds)
return err
}
- if err := d.setStat(ctx, rp.Credentials(), &opts.Stat, rp.Mount()); err != nil {
+ if err := d.setStat(ctx, rp.Credentials(), &opts, rp.Mount()); err != nil {
fs.renameMuRUnlockAndCheckCaching(&ds)
return err
}
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index b74d489a0..e20de84b5 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -785,8 +785,8 @@ func (d *dentry) cachedMetadataAuthoritative() bool {
// updateFromP9Attrs is called to update d's metadata after an update from the
// remote filesystem.
-func (d *dentry) updateFromP9Attrs(mask p9.AttrMask, attr *p9.Attr) {
- d.metadataMu.Lock()
+// Precondition: d.metadataMu must be locked.
+func (d *dentry) updateFromP9AttrsLocked(mask p9.AttrMask, attr *p9.Attr) {
if mask.Mode {
if got, want := uint32(attr.Mode.FileType()), d.fileType(); got != want {
d.metadataMu.Unlock()
@@ -822,7 +822,6 @@ func (d *dentry) updateFromP9Attrs(mask p9.AttrMask, attr *p9.Attr) {
if mask.Size {
d.updateFileSizeLocked(attr.Size)
}
- d.metadataMu.Unlock()
}
// Preconditions: !d.isSynthetic()
@@ -834,6 +833,10 @@ func (d *dentry) updateFromGetattr(ctx context.Context) error {
file p9file
handleMuRLocked bool
)
+ // d.metadataMu must be locked *before* we getAttr so that we do not end up
+ // updating stale attributes in d.updateFromP9AttrsLocked().
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
d.handleMu.RLock()
if !d.handle.file.isNil() {
file = d.handle.file
@@ -849,7 +852,7 @@ func (d *dentry) updateFromGetattr(ctx context.Context) error {
if err != nil {
return err
}
- d.updateFromP9Attrs(attrMask, &attr)
+ d.updateFromP9AttrsLocked(attrMask, &attr)
return nil
}
@@ -885,7 +888,8 @@ func (d *dentry) statTo(stat *linux.Statx) {
stat.DevMinor = d.fs.devMinor
}
-func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx, mnt *vfs.Mount) error {
+func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs.SetStatOptions, mnt *vfs.Mount) error {
+ stat := &opts.Stat
if stat.Mask == 0 {
return nil
}
@@ -893,7 +897,7 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
return syserror.EPERM
}
mode := linux.FileMode(atomic.LoadUint32(&d.mode))
- if err := vfs.CheckSetStat(ctx, creds, stat, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
+ if err := vfs.CheckSetStat(ctx, creds, opts, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
return err
}
if err := mnt.CheckBeginWrite(); err != nil {
@@ -934,6 +938,17 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
}
if !d.isSynthetic() {
if stat.Mask != 0 {
+ if stat.Mask&linux.STATX_SIZE != 0 {
+ // Check whether to allow a truncate request to be made.
+ switch d.mode & linux.S_IFMT {
+ case linux.S_IFREG:
+ // Allow.
+ case linux.S_IFDIR:
+ return syserror.EISDIR
+ default:
+ return syserror.EINVAL
+ }
+ }
if err := d.file.setAttr(ctx, p9.SetAttrMask{
Permissions: stat.Mask&linux.STATX_MODE != 0,
UID: stat.Mask&linux.STATX_UID != 0,
@@ -1495,7 +1510,7 @@ func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linu
// SetStat implements vfs.FileDescriptionImpl.SetStat.
func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
- if err := fd.dentry().setStat(ctx, auth.CredentialsFromContext(ctx), &opts.Stat, fd.vfsfd.Mount()); err != nil {
+ if err := fd.dentry().setStat(ctx, auth.CredentialsFromContext(ctx), &opts, fd.vfsfd.Mount()); err != nil {
return err
}
if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 {
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index f10350c97..02317a133 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -155,26 +155,53 @@ func (fd *regularFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ n, _, err := fd.pwrite(ctx, src, offset, opts)
+ return n, err
+}
+
+// pwrite returns the number of bytes written, final offset, error. The final
+// offset should be ignored by PWrite.
+func (fd *regularFileFD) pwrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (written, finalOff int64, err error) {
if offset < 0 {
- return 0, syserror.EINVAL
+ return 0, offset, syserror.EINVAL
}
// Check that flags are supported.
//
// TODO(gvisor.dev/issue/2601): Support select pwritev2 flags.
if opts.Flags&^linux.RWF_HIPRI != 0 {
- return 0, syserror.EOPNOTSUPP
+ return 0, offset, syserror.EOPNOTSUPP
+ }
+
+ d := fd.dentry()
+ // If the fd was opened with O_APPEND, make sure the file size is updated.
+ // There is a possible race here if size is modified externally after
+ // metadata cache is updated.
+ if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 && !d.cachedMetadataAuthoritative() {
+ if err := d.updateFromGetattr(ctx); err != nil {
+ return 0, offset, err
+ }
}
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
+ // Set offset to file size if the fd was opened with O_APPEND.
+ if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 {
+ // Holding d.metadataMu is sufficient for reading d.size.
+ offset = int64(d.size)
+ }
limit, err := vfs.CheckLimit(ctx, offset, src.NumBytes())
if err != nil {
- return 0, err
+ return 0, offset, err
}
src = src.TakeFirst64(limit)
+ n, err := fd.pwriteLocked(ctx, src, offset, opts)
+ return n, offset + n, err
+}
+// Preconditions: fd.dentry().metatdataMu must be locked.
+func (fd *regularFileFD) pwriteLocked(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
d := fd.dentry()
- d.metadataMu.Lock()
- defer d.metadataMu.Unlock()
if d.fs.opts.interop != InteropModeShared {
// Compare Linux's mm/filemap.c:__generic_file_write_iter() =>
// file_update_time(). This is d.touchCMtime(), but without locking
@@ -237,8 +264,8 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
// Write implements vfs.FileDescriptionImpl.Write.
func (fd *regularFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
fd.mu.Lock()
- n, err := fd.PWrite(ctx, src, fd.off, opts)
- fd.off += n
+ n, off, err := fd.pwrite(ctx, src, fd.off, opts)
+ fd.off = off
fd.mu.Unlock()
return n, err
}
diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go
index a7b53b2d2..811528982 100644
--- a/pkg/sentry/fsimpl/gofer/special_file.go
+++ b/pkg/sentry/fsimpl/gofer/special_file.go
@@ -16,6 +16,7 @@ package gofer
import (
"sync"
+ "sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
@@ -144,7 +145,7 @@ func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs
// mmap due to lock ordering; MM locks precede dentry.dataMu. That doesn't
// hold here since specialFileFD doesn't client-cache data. Just buffer the
// read instead.
- if d := fd.dentry(); d.fs.opts.interop != InteropModeShared {
+ if d := fd.dentry(); d.cachedMetadataAuthoritative() {
d.touchAtime(fd.vfsfd.Mount())
}
buf := make([]byte, dst.NumBytes())
@@ -176,39 +177,76 @@ func (fd *specialFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *specialFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ n, _, err := fd.pwrite(ctx, src, offset, opts)
+ return n, err
+}
+
+// pwrite returns the number of bytes written, final offset, error. The final
+// offset should be ignored by PWrite.
+func (fd *specialFileFD) pwrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (written, finalOff int64, err error) {
if fd.seekable && offset < 0 {
- return 0, syserror.EINVAL
+ return 0, offset, syserror.EINVAL
}
// Check that flags are supported.
//
// TODO(gvisor.dev/issue/2601): Support select pwritev2 flags.
if opts.Flags&^linux.RWF_HIPRI != 0 {
- return 0, syserror.EOPNOTSUPP
+ return 0, offset, syserror.EOPNOTSUPP
+ }
+
+ d := fd.dentry()
+ // If the regular file fd was opened with O_APPEND, make sure the file size
+ // is updated. There is a possible race here if size is modified externally
+ // after metadata cache is updated.
+ if fd.seekable && fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 && !d.cachedMetadataAuthoritative() {
+ if err := d.updateFromGetattr(ctx); err != nil {
+ return 0, offset, err
+ }
}
if fd.seekable {
+ // We need to hold the metadataMu *while* writing to a regular file.
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
+
+ // Set offset to file size if the regular file was opened with O_APPEND.
+ if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 {
+ // Holding d.metadataMu is sufficient for reading d.size.
+ offset = int64(d.size)
+ }
limit, err := vfs.CheckLimit(ctx, offset, src.NumBytes())
if err != nil {
- return 0, err
+ return 0, offset, err
}
src = src.TakeFirst64(limit)
}
// Do a buffered write. See rationale in PRead.
- if d := fd.dentry(); d.fs.opts.interop != InteropModeShared {
+ if d.cachedMetadataAuthoritative() {
d.touchCMtime()
}
buf := make([]byte, src.NumBytes())
// Don't do partial writes if we get a partial read from src.
if _, err := src.CopyIn(ctx, buf); err != nil {
- return 0, err
+ return 0, offset, err
}
n, err := fd.handle.writeFromBlocksAt(ctx, safemem.BlockSeqOf(safemem.BlockFromSafeSlice(buf)), uint64(offset))
if err == syserror.EAGAIN {
err = syserror.ErrWouldBlock
}
- return int64(n), err
+ finalOff = offset
+ // Update file size for regular files.
+ if fd.seekable {
+ finalOff += int64(n)
+ // d.metadataMu is already locked at this point.
+ if uint64(finalOff) > d.size {
+ d.dataMu.Lock()
+ defer d.dataMu.Unlock()
+ atomic.StoreUint64(&d.size, uint64(finalOff))
+ }
+ }
+ return int64(n), finalOff, err
}
// Write implements vfs.FileDescriptionImpl.Write.
@@ -218,8 +256,8 @@ func (fd *specialFileFD) Write(ctx context.Context, src usermem.IOSequence, opts
}
fd.mu.Lock()
- n, err := fd.PWrite(ctx, src, fd.off, opts)
- fd.off += n
+ n, off, err := fd.pwrite(ctx, src, fd.off, opts)
+ fd.off = off
fd.mu.Unlock()
return n, err
}
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
index 1a88cb657..c894f2ca0 100644
--- a/pkg/sentry/fsimpl/host/host.go
+++ b/pkg/sentry/fsimpl/host/host.go
@@ -373,7 +373,7 @@ func (i *inode) fstat(fs *filesystem) (linux.Statx, error) {
// SetStat implements kernfs.Inode.
func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error {
- s := opts.Stat
+ s := &opts.Stat
m := s.Mask
if m == 0 {
@@ -386,7 +386,7 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre
if err := syscall.Fstat(i.hostFD, &hostStat); err != nil {
return err
}
- if err := vfs.CheckSetStat(ctx, creds, &s, linux.FileMode(hostStat.Mode&linux.PermissionsMask), auth.KUID(hostStat.Uid), auth.KGID(hostStat.Gid)); err != nil {
+ if err := vfs.CheckSetStat(ctx, creds, &opts, linux.FileMode(hostStat.Mode), auth.KUID(hostStat.Uid), auth.KGID(hostStat.Gid)); err != nil {
return err
}
@@ -396,6 +396,9 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre
}
}
if m&linux.STATX_SIZE != 0 {
+ if hostStat.Mode&linux.S_IFMT != linux.S_IFREG {
+ return syserror.EINVAL
+ }
if err := syscall.Ftruncate(i.hostFD, int64(s.Size)); err != nil {
return err
}
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index 3f0aea73a..1d37ccb98 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -112,7 +112,7 @@ func (fd *GenericDirectoryFD) PWrite(ctx context.Context, src usermem.IOSequence
return fd.DirectoryFileDescriptionDefaultImpl.PWrite(ctx, src, offset, opts)
}
-// Release implements vfs.FileDecriptionImpl.Release.
+// Release implements vfs.FileDescriptionImpl.Release.
func (fd *GenericDirectoryFD) Release() {}
func (fd *GenericDirectoryFD) filesystem() *vfs.Filesystem {
@@ -123,7 +123,7 @@ func (fd *GenericDirectoryFD) inode() Inode {
return fd.vfsfd.VirtualDentry().Dentry().Impl().(*Dentry).inode
}
-// IterDirents implements vfs.FileDecriptionImpl.IterDirents. IterDirents holds
+// IterDirents implements vfs.FileDescriptionImpl.IterDirents. IterDirents holds
// o.mu when calling cb.
func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback) error {
fd.mu.Lock()
@@ -198,7 +198,7 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
return err
}
-// Seek implements vfs.FileDecriptionImpl.Seek.
+// Seek implements vfs.FileDescriptionImpl.Seek.
func (fd *GenericDirectoryFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
fd.mu.Lock()
defer fd.mu.Unlock()
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 2ab3f1761..579e627f0 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -267,7 +267,7 @@ func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *aut
if opts.Stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID) != 0 {
return syserror.EPERM
}
- if err := vfs.CheckSetStat(ctx, creds, &opts.Stat, a.Mode(), auth.KUID(atomic.LoadUint32(&a.uid)), auth.KGID(atomic.LoadUint32(&a.gid))); err != nil {
+ if err := vfs.CheckSetStat(ctx, creds, &opts, a.Mode(), auth.KUID(atomic.LoadUint32(&a.uid)), auth.KGID(atomic.LoadUint32(&a.gid))); err != nil {
return err
}
diff --git a/pkg/sentry/fsimpl/overlay/filesystem.go b/pkg/sentry/fsimpl/overlay/filesystem.go
index ff82e1f20..6b705e955 100644
--- a/pkg/sentry/fsimpl/overlay/filesystem.go
+++ b/pkg/sentry/fsimpl/overlay/filesystem.go
@@ -1104,7 +1104,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts
}
mode := linux.FileMode(atomic.LoadUint32(&d.mode))
- if err := vfs.CheckSetStat(ctx, rp.Credentials(), &opts.Stat, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
+ if err := vfs.CheckSetStat(ctx, rp.Credentials(), &opts, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
return err
}
mnt := rp.Mount()
diff --git a/pkg/sentry/fsimpl/overlay/non_directory.go b/pkg/sentry/fsimpl/overlay/non_directory.go
index a3c1f7a8d..c0749e711 100644
--- a/pkg/sentry/fsimpl/overlay/non_directory.go
+++ b/pkg/sentry/fsimpl/overlay/non_directory.go
@@ -151,7 +151,7 @@ func (fd *nonDirectoryFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux
func (fd *nonDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
d := fd.dentry()
mode := linux.FileMode(atomic.LoadUint32(&d.mode))
- if err := vfs.CheckSetStat(ctx, auth.CredentialsFromContext(ctx), &opts.Stat, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
+ if err := vfs.CheckSetStat(ctx, auth.CredentialsFromContext(ctx), &opts, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
return err
}
mnt := fd.vfsfd.Mount()
@@ -176,7 +176,7 @@ func (fd *nonDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptions)
return nil
}
-// StatFS implements vfs.FileDesciptionImpl.StatFS.
+// StatFS implements vfs.FileDescriptionImpl.StatFS.
func (fd *nonDirectoryFD) StatFS(ctx context.Context) (linux.Statfs, error) {
return fd.filesystem().statFS(ctx)
}
diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go
index dad4db1a7..79c2725f3 100644
--- a/pkg/sentry/fsimpl/proc/subtasks.go
+++ b/pkg/sentry/fsimpl/proc/subtasks.go
@@ -128,7 +128,7 @@ func (fd *subtasksFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallbac
return fd.GenericDirectoryFD.IterDirents(ctx, cb)
}
-// Seek implements vfs.FileDecriptionImpl.Seek.
+// Seek implements vfs.FileDescriptionImpl.Seek.
func (fd *subtasksFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
if fd.task.ExitState() >= kernel.TaskExitZombie {
return 0, syserror.ENOENT
diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index a0f20c2d4..ef210a69b 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -649,7 +649,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts
fs.mu.RUnlock()
return err
}
- if err := d.inode.setStat(ctx, rp.Credentials(), &opts.Stat); err != nil {
+ if err := d.inode.setStat(ctx, rp.Credentials(), &opts); err != nil {
fs.mu.RUnlock()
return err
}
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index 1cdb46e6f..abbaa5d60 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -325,8 +325,15 @@ func (fd *regularFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ n, _, err := fd.pwrite(ctx, src, offset, opts)
+ return n, err
+}
+
+// pwrite returns the number of bytes written, final offset and error. The
+// final offset should be ignored by PWrite.
+func (fd *regularFileFD) pwrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (written, finalOff int64, err error) {
if offset < 0 {
- return 0, syserror.EINVAL
+ return 0, offset, syserror.EINVAL
}
// Check that flags are supported. RWF_DSYNC/RWF_SYNC can be ignored since
@@ -334,40 +341,44 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
//
// TODO(gvisor.dev/issue/2601): Support select preadv2 flags.
if opts.Flags&^(linux.RWF_HIPRI|linux.RWF_DSYNC|linux.RWF_SYNC) != 0 {
- return 0, syserror.EOPNOTSUPP
+ return 0, offset, syserror.EOPNOTSUPP
}
srclen := src.NumBytes()
if srclen == 0 {
- return 0, nil
+ return 0, offset, nil
}
f := fd.inode().impl.(*regularFile)
+ f.inode.mu.Lock()
+ defer f.inode.mu.Unlock()
+ // If the file is opened with O_APPEND, update offset to file size.
+ if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 {
+ // Locking f.inode.mu is sufficient for reading f.size.
+ offset = int64(f.size)
+ }
if end := offset + srclen; end < offset {
// Overflow.
- return 0, syserror.EINVAL
+ return 0, offset, syserror.EINVAL
}
- var err error
srclen, err = vfs.CheckLimit(ctx, offset, srclen)
if err != nil {
- return 0, err
+ return 0, offset, err
}
src = src.TakeFirst64(srclen)
- f.inode.mu.Lock()
rw := getRegularFileReadWriter(f, offset)
n, err := src.CopyInTo(ctx, rw)
- fd.inode().touchCMtimeLocked()
- f.inode.mu.Unlock()
+ f.inode.touchCMtimeLocked()
putRegularFileReadWriter(rw)
- return n, err
+ return n, n + offset, err
}
// Write implements vfs.FileDescriptionImpl.Write.
func (fd *regularFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
fd.offMu.Lock()
- n, err := fd.PWrite(ctx, src, fd.off, opts)
- fd.off += n
+ n, off, err := fd.pwrite(ctx, src, fd.off, opts)
+ fd.off = off
fd.offMu.Unlock()
return n, err
}
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index d7f4f0779..2545d88e9 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -452,7 +452,8 @@ func (i *inode) statTo(stat *linux.Statx) {
}
}
-func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx) error {
+func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs.SetStatOptions) error {
+ stat := &opts.Stat
if stat.Mask == 0 {
return nil
}
@@ -460,7 +461,7 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
return syserror.EPERM
}
mode := linux.FileMode(atomic.LoadUint32(&i.mode))
- if err := vfs.CheckSetStat(ctx, creds, stat, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
+ if err := vfs.CheckSetStat(ctx, creds, opts, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
return err
}
i.mu.Lock()
@@ -695,7 +696,7 @@ func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linu
func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
creds := auth.CredentialsFromContext(ctx)
d := fd.dentry()
- if err := d.inode.setStat(ctx, creds, &opts.Stat); err != nil {
+ if err := d.inode.setStat(ctx, creds, &opts); err != nil {
return err
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 09:32:06 +0000