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-rw-r--r--pkg/sentry/fsimpl/gofer/filesystem.go35
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go74
-rw-r--r--pkg/sentry/fsimpl/gofer/regular_file.go37
-rw-r--r--pkg/sentry/fsimpl/gofer/special_file.go13
-rw-r--r--pkg/sentry/fsimpl/gofer/time.go12
-rw-r--r--pkg/sentry/fsimpl/host/host.go14
-rw-r--r--pkg/sentry/fsimpl/host/socket.go9
-rw-r--r--pkg/sentry/fsimpl/kernfs/fd_impl_util.go5
-rw-r--r--pkg/sentry/fsimpl/proc/task_files.go8
-rw-r--r--pkg/sentry/fsimpl/sys/sys.go2
-rw-r--r--pkg/sentry/fsimpl/sys/sys_test.go2
-rw-r--r--pkg/sentry/fsimpl/tmpfs/filesystem.go6
-rw-r--r--pkg/sentry/fsimpl/tmpfs/regular_file.go29
13 files changed, 174 insertions, 72 deletions
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index 51082359d..7bcc99b29 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -869,11 +869,22 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
if err := d.checkPermissions(rp.Credentials(), ats); err != nil {
return nil, err
}
+
+ trunc := opts.Flags&linux.O_TRUNC != 0 && d.fileType() == linux.S_IFREG
+ if trunc {
+ // Lock metadataMu *while* we open a regular file with O_TRUNC because
+ // open(2) will change the file size on server.
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
+ }
+
+ var vfd *vfs.FileDescription
+ var err error
mnt := rp.Mount()
switch d.fileType() {
case linux.S_IFREG:
if !d.fs.opts.regularFilesUseSpecialFileFD {
- if err := d.ensureSharedHandle(ctx, ats&vfs.MayRead != 0, ats&vfs.MayWrite != 0, opts.Flags&linux.O_TRUNC != 0); err != nil {
+ if err := d.ensureSharedHandle(ctx, ats&vfs.MayRead != 0, ats&vfs.MayWrite != 0, trunc); err != nil {
return nil, err
}
fd := &regularFileFD{}
@@ -883,7 +894,7 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
}); err != nil {
return nil, err
}
- return &fd.vfsfd, nil
+ vfd = &fd.vfsfd
}
case linux.S_IFDIR:
// Can't open directories with O_CREAT.
@@ -923,7 +934,25 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
return d.pipe.Open(ctx, mnt, &d.vfsd, opts.Flags, &d.locks)
}
}
- return d.openSpecialFileLocked(ctx, mnt, opts)
+
+ if vfd == nil {
+ if vfd, err = d.openSpecialFileLocked(ctx, mnt, opts); err != nil {
+ return nil, err
+ }
+ }
+
+ if trunc {
+ // If no errors occured so far then update file size in memory. This
+ // step is required even if !d.cachedMetadataAuthoritative() because
+ // d.mappings has to be updated.
+ // d.metadataMu has already been acquired if trunc == true.
+ d.updateFileSizeLocked(0)
+
+ if d.cachedMetadataAuthoritative() {
+ d.touchCMtimeLocked()
+ }
+ }
+ return vfd, err
}
func (d *dentry) connectSocketLocked(ctx context.Context, opts *vfs.OpenOptions) (*vfs.FileDescription, error) {
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 71c8d3ae1..8e74e60a5 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -794,9 +794,7 @@ func (d *dentry) updateFromP9Attrs(mask p9.AttrMask, attr *p9.Attr) {
atomic.StoreUint32(&d.nlink, uint32(attr.NLink))
}
if mask.Size {
- d.dataMu.Lock()
- atomic.StoreUint64(&d.size, attr.Size)
- d.dataMu.Unlock()
+ d.updateFileSizeLocked(attr.Size)
}
d.metadataMu.Unlock()
}
@@ -902,6 +900,12 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
}
d.metadataMu.Lock()
defer d.metadataMu.Unlock()
+ if stat.Mask&linux.STATX_SIZE != 0 {
+ // The size needs to be changed even when
+ // !d.cachedMetadataAuthoritative() because d.mappings has to be
+ // updated.
+ d.updateFileSizeLocked(stat.Size)
+ }
if !d.isSynthetic() {
if stat.Mask != 0 {
if err := d.file.setAttr(ctx, p9.SetAttrMask{
@@ -963,40 +967,42 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
stat.Mask |= linux.STATX_MTIME
}
atomic.StoreInt64(&d.ctime, now)
- if stat.Mask&linux.STATX_SIZE != 0 {
+ return nil
+}
+
+// Preconditions: d.metadataMu must be locked.
+func (d *dentry) updateFileSizeLocked(newSize uint64) {
+ d.dataMu.Lock()
+ oldSize := d.size
+ d.size = newSize
+ // d.dataMu must be unlocked to lock d.mapsMu and invalidate mappings
+ // below. This allows concurrent calls to Read/Translate/etc. These
+ // functions synchronize with truncation by refusing to use cache
+ // contents beyond the new d.size. (We are still holding d.metadataMu,
+ // so we can't race with Write or another truncate.)
+ d.dataMu.Unlock()
+ if d.size < oldSize {
+ oldpgend, _ := usermem.PageRoundUp(oldSize)
+ newpgend, _ := usermem.PageRoundUp(d.size)
+ if oldpgend != newpgend {
+ d.mapsMu.Lock()
+ d.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,
+ })
+ d.mapsMu.Unlock()
+ }
+ // We are now guaranteed that there are no translations of
+ // truncated pages, and can remove them from the cache. Since
+ // truncated pages have been removed from the remote file, they
+ // should be dropped without being written back.
d.dataMu.Lock()
- oldSize := d.size
- d.size = stat.Size
- // d.dataMu must be unlocked to lock d.mapsMu and invalidate mappings
- // below. This allows concurrent calls to Read/Translate/etc. These
- // functions synchronize with truncation by refusing to use cache
- // contents beyond the new d.size. (We are still holding d.metadataMu,
- // so we can't race with Write or another truncate.)
+ d.cache.Truncate(d.size, d.fs.mfp.MemoryFile())
+ d.dirty.KeepClean(memmap.MappableRange{d.size, oldpgend})
d.dataMu.Unlock()
- if d.size < oldSize {
- oldpgend, _ := usermem.PageRoundUp(oldSize)
- newpgend, _ := usermem.PageRoundUp(d.size)
- if oldpgend != newpgend {
- d.mapsMu.Lock()
- d.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,
- })
- d.mapsMu.Unlock()
- }
- // We are now guaranteed that there are no translations of
- // truncated pages, and can remove them from the cache. Since
- // truncated pages have been removed from the remote file, they
- // should be dropped without being written back.
- d.dataMu.Lock()
- d.cache.Truncate(d.size, d.fs.mfp.MemoryFile())
- d.dirty.KeepClean(memmap.MappableRange{d.size, oldpgend})
- d.dataMu.Unlock()
- }
}
- return nil
}
func (d *dentry) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error {
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index 404a452c4..3d2d3530a 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -24,6 +24,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/log"
+ "gvisor.dev/gvisor/pkg/p9"
"gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -67,13 +68,43 @@ func (fd *regularFileFD) OnClose(ctx context.Context) error {
return d.handle.file.flush(ctx)
}
+// Allocate implements vfs.FileDescriptionImpl.Allocate.
+func (fd *regularFileFD) Allocate(ctx context.Context, mode, offset, length uint64) error {
+
+ d := fd.dentry()
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
+
+ size := offset + length
+
+ // Allocating a smaller size is a noop.
+ if size <= d.size {
+ return nil
+ }
+
+ d.handleMu.Lock()
+ defer d.handleMu.Unlock()
+
+ err := d.handle.file.allocate(ctx, p9.ToAllocateMode(mode), offset, length)
+ if err != nil {
+ return err
+ }
+ d.size = size
+ if !d.cachedMetadataAuthoritative() {
+ d.touchCMtimeLocked()
+ }
+ return nil
+}
+
// PRead implements vfs.FileDescriptionImpl.PRead.
func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
if offset < 0 {
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
+ // 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
}
@@ -126,7 +157,9 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
+ // 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
}
diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go
index a016cbae1..3c4e7e2e4 100644
--- a/pkg/sentry/fsimpl/gofer/special_file.go
+++ b/pkg/sentry/fsimpl/gofer/special_file.go
@@ -130,7 +130,9 @@ func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
+ // 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
}
@@ -176,7 +178,9 @@ func (fd *specialFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
+ // 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
}
@@ -235,8 +239,5 @@ func (fd *specialFileFD) Seek(ctx context.Context, offset int64, whence int32) (
// Sync implements vfs.FileDescriptionImpl.Sync.
func (fd *specialFileFD) Sync(ctx context.Context) error {
- if !fd.vfsfd.IsWritable() {
- return nil
- }
- return fd.handle.sync(ctx)
+ return fd.dentry().syncSharedHandle(ctx)
}
diff --git a/pkg/sentry/fsimpl/gofer/time.go b/pkg/sentry/fsimpl/gofer/time.go
index 1d5aa82dc..0eef4e16e 100644
--- a/pkg/sentry/fsimpl/gofer/time.go
+++ b/pkg/sentry/fsimpl/gofer/time.go
@@ -36,7 +36,7 @@ func statxTimestampFromDentry(ns int64) linux.StatxTimestamp {
}
}
-// Preconditions: fs.interop != InteropModeShared.
+// Preconditions: d.cachedMetadataAuthoritative() == true.
func (d *dentry) touchAtime(mnt *vfs.Mount) {
if mnt.Flags.NoATime {
return
@@ -51,8 +51,8 @@ func (d *dentry) touchAtime(mnt *vfs.Mount) {
mnt.EndWrite()
}
-// Preconditions: fs.interop != InteropModeShared. The caller has successfully
-// called vfs.Mount.CheckBeginWrite().
+// Preconditions: d.cachedMetadataAuthoritative() == true. The caller has
+// successfully called vfs.Mount.CheckBeginWrite().
func (d *dentry) touchCtime() {
now := d.fs.clock.Now().Nanoseconds()
d.metadataMu.Lock()
@@ -60,8 +60,8 @@ func (d *dentry) touchCtime() {
d.metadataMu.Unlock()
}
-// Preconditions: fs.interop != InteropModeShared. The caller has successfully
-// called vfs.Mount.CheckBeginWrite().
+// Preconditions: d.cachedMetadataAuthoritative() == true. The caller has
+// successfully called vfs.Mount.CheckBeginWrite().
func (d *dentry) touchCMtime() {
now := d.fs.clock.Now().Nanoseconds()
d.metadataMu.Lock()
@@ -70,6 +70,8 @@ func (d *dentry) touchCMtime() {
d.metadataMu.Unlock()
}
+// Preconditions: d.cachedMetadataAuthoritative() == true. The caller has
+// locked d.metadataMu.
func (d *dentry) touchCMtimeLocked() {
now := d.fs.clock.Now().Nanoseconds()
atomic.StoreInt64(&d.mtime, now)
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
index d5e73ddae..1cd2982cb 100644
--- a/pkg/sentry/fsimpl/host/host.go
+++ b/pkg/sentry/fsimpl/host/host.go
@@ -543,6 +543,16 @@ func (f *fileDescription) Release() {
// noop
}
+// Allocate implements vfs.FileDescriptionImpl.
+func (f *fileDescription) Allocate(ctx context.Context, mode, offset, length uint64) error {
+ if !f.inode.seekable {
+ return syserror.ESPIPE
+ }
+
+ // TODO(gvisor.dev/issue/2923): Implement Allocate for non-pipe hostfds.
+ return syserror.EOPNOTSUPP
+}
+
// PRead implements FileDescriptionImpl.
func (f *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
i := f.inode
@@ -578,8 +588,10 @@ func (f *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts
}
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 != 0 {
+ if flags&^linux.RWF_HIPRI != 0 {
return 0, syserror.EOPNOTSUPP
}
reader := hostfd.GetReadWriterAt(int32(hostFD), offset, flags)
diff --git a/pkg/sentry/fsimpl/host/socket.go b/pkg/sentry/fsimpl/host/socket.go
index 38f1fbfba..fd16bd92d 100644
--- a/pkg/sentry/fsimpl/host/socket.go
+++ b/pkg/sentry/fsimpl/host/socket.go
@@ -47,11 +47,6 @@ func newEndpoint(ctx context.Context, hostFD int, queue *waiter.Queue) (transpor
return ep, nil
}
-// maxSendBufferSize is the maximum host send buffer size allowed for endpoint.
-//
-// N.B. 8MB is the default maximum on Linux (2 * sysctl_wmem_max).
-const maxSendBufferSize = 8 << 20
-
// ConnectedEndpoint is an implementation of transport.ConnectedEndpoint and
// transport.Receiver. It is backed by a host fd that was imported at sentry
// startup. This fd is shared with a hostfs inode, which retains ownership of
@@ -114,10 +109,6 @@ func (c *ConnectedEndpoint) init() *syserr.Error {
if err != nil {
return syserr.FromError(err)
}
- if sndbuf > maxSendBufferSize {
- log.Warningf("Socket send buffer too large: %d", sndbuf)
- return syserr.ErrInvalidEndpointState
- }
c.stype = linux.SockType(stype)
c.sndbuf = int64(sndbuf)
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index 5f7853a2a..ca8b8c63b 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -236,6 +236,11 @@ func (fd *GenericDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptio
return inode.SetStat(ctx, fd.filesystem(), creds, opts)
}
+// Allocate implements vfs.FileDescriptionImpl.Allocate.
+func (fd *GenericDirectoryFD) Allocate(ctx context.Context, mode, offset, length uint64) error {
+ return fd.DirectoryFileDescriptionDefaultImpl.Allocate(ctx, mode, offset, length)
+}
+
// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
func (fd *GenericDirectoryFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error {
return fd.Locks().LockPOSIX(ctx, &fd.vfsfd, uid, t, start, length, whence, block)
diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index 286c23f01..9af43b859 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -231,8 +231,9 @@ func (d *cmdlineData) Generate(ctx context.Context, buf *bytes.Buffer) error {
// Linux will return envp up to and including the first NULL character,
// so find it.
- if end := bytes.IndexByte(buf.Bytes()[ar.Length():], 0); end != -1 {
- buf.Truncate(end)
+ envStart := int(ar.Length())
+ if nullIdx := bytes.IndexByte(buf.Bytes()[envStart:], 0); nullIdx != -1 {
+ buf.Truncate(envStart + nullIdx)
}
}
@@ -300,7 +301,7 @@ type idMapData struct {
var _ dynamicInode = (*idMapData)(nil)
-// Generate implements vfs.DynamicBytesSource.Generate.
+// Generate implements vfs.WritableDynamicBytesSource.Generate.
func (d *idMapData) Generate(ctx context.Context, buf *bytes.Buffer) error {
var entries []auth.IDMapEntry
if d.gids {
@@ -314,6 +315,7 @@ func (d *idMapData) Generate(ctx context.Context, buf *bytes.Buffer) error {
return nil
}
+// Write implements vfs.WritableDynamicBytesSource.Write.
func (d *idMapData) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
// "In addition, the number of bytes written to the file must be less than
// the system page size, and the write must be performed at the start of
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
index fe02f7ee9..01ce30a4d 100644
--- a/pkg/sentry/fsimpl/sys/sys.go
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -138,7 +138,7 @@ type cpuFile struct {
// Generate implements vfs.DynamicBytesSource.Generate.
func (c *cpuFile) Generate(ctx context.Context, buf *bytes.Buffer) error {
- fmt.Fprintf(buf, "0-%d", c.maxCores-1)
+ fmt.Fprintf(buf, "0-%d\n", c.maxCores-1)
return nil
}
diff --git a/pkg/sentry/fsimpl/sys/sys_test.go b/pkg/sentry/fsimpl/sys/sys_test.go
index 4b3602d47..242d5fd12 100644
--- a/pkg/sentry/fsimpl/sys/sys_test.go
+++ b/pkg/sentry/fsimpl/sys/sys_test.go
@@ -51,7 +51,7 @@ func TestReadCPUFile(t *testing.T) {
k := kernel.KernelFromContext(s.Ctx)
maxCPUCores := k.ApplicationCores()
- expected := fmt.Sprintf("0-%d", maxCPUCores-1)
+ expected := fmt.Sprintf("0-%d\n", maxCPUCores-1)
for _, fname := range []string{"online", "possible", "present"} {
pop := s.PathOpAtRoot(fmt.Sprintf("devices/system/cpu/%s", fname))
diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index 71ac7b8e6..ed40f6b52 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -407,10 +407,10 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open
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 {
+ if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{AllowDirectIO: true}); err != nil {
return nil, err
}
- if opts.Flags&linux.O_TRUNC != 0 {
+ if !afterCreate && opts.Flags&linux.O_TRUNC != 0 {
if _, err := impl.truncate(0); err != nil {
return nil, err
}
@@ -423,7 +423,7 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open
}
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 {
+ if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{AllowDirectIO: true}); err != nil {
return nil, err
}
return &fd.vfsfd, nil
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index b805aadd0..1cdb46e6f 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -274,14 +274,32 @@ func (fd *regularFileFD) Release() {
// noop
}
+// Allocate implements vfs.FileDescriptionImpl.Allocate.
+func (fd *regularFileFD) Allocate(ctx context.Context, mode, offset, length uint64) error {
+ f := fd.inode().impl.(*regularFile)
+
+ f.inode.mu.Lock()
+ defer f.inode.mu.Unlock()
+ oldSize := f.size
+ size := offset + length
+ if oldSize >= size {
+ return nil
+ }
+ _, err := f.truncateLocked(size)
+ return err
+}
+
// PRead implements vfs.FileDescriptionImpl.PRead.
func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
if offset < 0 {
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
- if opts.Flags&^linux.RWF_HIPRI != 0 {
+ // Check that flags are supported. RWF_DSYNC/RWF_SYNC can be ignored since
+ // all state is in-memory.
+ //
+ // 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
}
@@ -311,8 +329,11 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
return 0, syserror.EINVAL
}
- // Check that flags are supported. Silently ignore RWF_HIPRI.
- if opts.Flags&^linux.RWF_HIPRI != 0 {
+ // Check that flags are supported. RWF_DSYNC/RWF_SYNC can be ignored since
+ // all state is in-memory.
+ //
+ // 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
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-02 22:44:30 +0000