diff options
Diffstat (limited to 'pkg/sentry/fsimpl/gofer')
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/BUILD | 1 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/gofer.go | 77 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/pagemath.go | 31 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/regular_file.go | 47 |
4 files changed, 70 insertions, 86 deletions
diff --git a/pkg/sentry/fsimpl/gofer/BUILD b/pkg/sentry/fsimpl/gofer/BUILD index 5ce82b793..67e916525 100644 --- a/pkg/sentry/fsimpl/gofer/BUILD +++ b/pkg/sentry/fsimpl/gofer/BUILD @@ -36,7 +36,6 @@ go_library( "gofer.go", "handle.go", "p9file.go", - "pagemath.go", "regular_file.go", "socket.go", "special_file.go", diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index 1da8d5d82..3f3bd56f0 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -84,12 +84,6 @@ type filesystem struct { // devMinor is the filesystem's minor device number. devMinor is immutable. devMinor uint32 - // uid and gid are the effective KUID and KGID of the filesystem's creator, - // and are used as the owner and group for files that don't specify one. - // uid and gid are immutable. - uid auth.KUID - gid auth.KGID - // renameMu serves two purposes: // // - It synchronizes path resolution with renaming initiated by this @@ -122,6 +116,8 @@ type filesystemOptions struct { fd int aname string interop InteropMode // derived from the "cache" mount option + dfltuid auth.KUID + dfltgid auth.KGID msize uint32 version string @@ -143,9 +139,12 @@ type filesystemOptions struct { // If overlayfsStaleRead is true, O_RDONLY host FDs provided by the remote // filesystem may not be coherent with writable host FDs opened later, so - // mappings of the former must be replaced by mappings of the latter. This - // is usually only the case when the remote filesystem is an overlayfs - // mount on Linux < 4.19. + // all uses of the former must be replaced by uses of the latter. This is + // usually only the case when the remote filesystem is a Linux overlayfs + // mount. (Prior to Linux 4.18, patch series centered on commit + // d1d04ef8572b "ovl: stack file ops", both I/O and memory mappings were + // incoherent between pre-copy-up and post-copy-up FDs; after that patch + // series, only memory mappings are incoherent.) overlayfsStaleRead bool // If regularFilesUseSpecialFileFD is true, application FDs representing @@ -227,6 +226,15 @@ type InternalFilesystemOptions struct { OpenSocketsByConnecting bool } +// _V9FS_DEFUID and _V9FS_DEFGID (from Linux's fs/9p/v9fs.h) are the default +// UIDs and GIDs used for files that do not provide a specific owner or group +// respectively. +const ( + // uint32(-2) doesn't work in Go. + _V9FS_DEFUID = auth.KUID(4294967294) + _V9FS_DEFGID = auth.KGID(4294967294) +) + // Name implements vfs.FilesystemType.Name. func (FilesystemType) Name() string { return Name @@ -312,6 +320,31 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt } } + // Parse the default UID and GID. + fsopts.dfltuid = _V9FS_DEFUID + if dfltuidstr, ok := mopts["dfltuid"]; ok { + delete(mopts, "dfltuid") + dfltuid, err := strconv.ParseUint(dfltuidstr, 10, 32) + if err != nil { + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: dfltuid=%s", dfltuidstr) + return nil, nil, syserror.EINVAL + } + // In Linux, dfltuid is interpreted as a UID and is converted to a KUID + // in the caller's user namespace, but goferfs isn't + // application-mountable. + fsopts.dfltuid = auth.KUID(dfltuid) + } + fsopts.dfltgid = _V9FS_DEFGID + if dfltgidstr, ok := mopts["dfltgid"]; ok { + delete(mopts, "dfltgid") + dfltgid, err := strconv.ParseUint(dfltgidstr, 10, 32) + if err != nil { + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: dfltgid=%s", dfltgidstr) + return nil, nil, syserror.EINVAL + } + fsopts.dfltgid = auth.KGID(dfltgid) + } + // Parse the 9P message size. fsopts.msize = 1024 * 1024 // 1M, tested to give good enough performance up to 64M if msizestr, ok := mopts["msize"]; ok { @@ -419,8 +452,6 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt client: client, clock: ktime.RealtimeClockFromContext(ctx), devMinor: devMinor, - uid: creds.EffectiveKUID, - gid: creds.EffectiveKGID, syncableDentries: make(map[*dentry]struct{}), specialFileFDs: make(map[*specialFileFD]struct{}), } @@ -669,8 +700,8 @@ func (fs *filesystem) newDentry(ctx context.Context, file p9file, qid p9.QID, ma file: file, ino: qid.Path, mode: uint32(attr.Mode), - uid: uint32(fs.uid), - gid: uint32(fs.gid), + uid: uint32(fs.opts.dfltuid), + gid: uint32(fs.opts.dfltgid), blockSize: usermem.PageSize, handle: handle{ fd: -1, @@ -866,8 +897,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin Size: stat.Mask&linux.STATX_SIZE != 0, ATime: stat.Mask&linux.STATX_ATIME != 0, MTime: stat.Mask&linux.STATX_MTIME != 0, - ATimeNotSystemTime: stat.Atime.Nsec != linux.UTIME_NOW, - MTimeNotSystemTime: stat.Mtime.Nsec != linux.UTIME_NOW, + ATimeNotSystemTime: stat.Mask&linux.STATX_ATIME != 0 && stat.Atime.Nsec != linux.UTIME_NOW, + MTimeNotSystemTime: stat.Mask&linux.STATX_MTIME != 0 && stat.Mtime.Nsec != linux.UTIME_NOW, }, p9.SetAttr{ Permissions: p9.FileMode(stat.Mode), UID: p9.UID(stat.UID), @@ -925,8 +956,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin // so we can't race with Write or another truncate.) d.dataMu.Unlock() if d.size < oldSize { - oldpgend := pageRoundUp(oldSize) - newpgend := pageRoundUp(d.size) + oldpgend, _ := usermem.PageRoundUp(oldSize) + newpgend, _ := usermem.PageRoundUp(d.size) if oldpgend != newpgend { d.mapsMu.Lock() d.mappings.Invalidate(memmap.MappableRange{newpgend, oldpgend}, memmap.InvalidateOpts{ @@ -1008,6 +1039,18 @@ func (d *dentry) decRefLocked() { } } +// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent. +// +// TODO(gvisor.dev/issue/1479): Implement inotify. +func (d *dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) {} + +// Watches implements vfs.DentryImpl.Watches. +// +// TODO(gvisor.dev/issue/1479): Implement inotify. +func (d *dentry) Watches() *vfs.Watches { + return nil +} + // checkCachingLocked should be called after d's reference count becomes 0 or it // becomes disowned. // diff --git a/pkg/sentry/fsimpl/gofer/pagemath.go b/pkg/sentry/fsimpl/gofer/pagemath.go deleted file mode 100644 index 847cb0784..000000000 --- a/pkg/sentry/fsimpl/gofer/pagemath.go +++ /dev/null @@ -1,31 +0,0 @@ -// 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 gofer - -import ( - "gvisor.dev/gvisor/pkg/usermem" -) - -// This are equivalent to usermem.Addr.RoundDown/Up, but without the -// potentially truncating conversion to usermem.Addr. This is necessary because -// there is no way to define generic "PageRoundDown/Up" functions in Go. - -func pageRoundDown(x uint64) uint64 { - return x &^ (usermem.PageSize - 1) -} - -func pageRoundUp(x uint64) uint64 { - return pageRoundDown(x + usermem.PageSize - 1) -} diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go index 857f7c74e..0d10cf7ac 100644 --- a/pkg/sentry/fsimpl/gofer/regular_file.go +++ b/pkg/sentry/fsimpl/gofer/regular_file.go @@ -148,9 +148,9 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off return 0, err } // Remove touched pages from the cache. - pgstart := pageRoundDown(uint64(offset)) - pgend := pageRoundUp(uint64(offset + src.NumBytes())) - if pgend < pgstart { + pgstart := usermem.PageRoundDown(uint64(offset)) + pgend, ok := usermem.PageRoundUp(uint64(offset + src.NumBytes())) + if !ok { return 0, syserror.EINVAL } mr := memmap.MappableRange{pgstart, pgend} @@ -306,9 +306,10 @@ func (rw *dentryReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) if fillCache { // Read into the cache, then re-enter the loop to read from the // cache. + gapEnd, _ := usermem.PageRoundUp(gapMR.End) reqMR := memmap.MappableRange{ - Start: pageRoundDown(gapMR.Start), - End: pageRoundUp(gapMR.End), + Start: usermem.PageRoundDown(gapMR.Start), + End: gapEnd, } optMR := gap.Range() err := rw.d.cache.Fill(rw.ctx, reqMR, maxFillRange(reqMR, optMR), mf, usage.PageCache, rw.d.handle.readToBlocksAt) @@ -671,7 +672,7 @@ func (d *dentry) Translate(ctx context.Context, required, optional memmap.Mappab // Constrain translations to d.size (rounded up) to prevent translation to // pages that may be concurrently truncated. - pgend := pageRoundUp(d.size) + pgend, _ := usermem.PageRoundUp(d.size) var beyondEOF bool if required.End > pgend { if required.Start >= pgend { @@ -818,43 +819,15 @@ type dentryPlatformFile struct { // IncRef implements platform.File.IncRef. func (d *dentryPlatformFile) IncRef(fr platform.FileRange) { d.dataMu.Lock() - seg, gap := d.fdRefs.Find(fr.Start) - for { - switch { - case seg.Ok() && seg.Start() < fr.End: - seg = d.fdRefs.Isolate(seg, fr) - seg.SetValue(seg.Value() + 1) - seg, gap = seg.NextNonEmpty() - case gap.Ok() && gap.Start() < fr.End: - newRange := gap.Range().Intersect(fr) - usage.MemoryAccounting.Inc(newRange.Length(), usage.Mapped) - seg, gap = d.fdRefs.InsertWithoutMerging(gap, newRange, 1).NextNonEmpty() - default: - d.fdRefs.MergeAdjacent(fr) - d.dataMu.Unlock() - return - } - } + d.fdRefs.IncRefAndAccount(fr) + d.dataMu.Unlock() } // DecRef implements platform.File.DecRef. func (d *dentryPlatformFile) DecRef(fr platform.FileRange) { d.dataMu.Lock() - seg := d.fdRefs.FindSegment(fr.Start) - - for seg.Ok() && seg.Start() < fr.End { - seg = d.fdRefs.Isolate(seg, fr) - if old := seg.Value(); old == 1 { - usage.MemoryAccounting.Dec(seg.Range().Length(), usage.Mapped) - seg = d.fdRefs.Remove(seg).NextSegment() - } else { - seg.SetValue(old - 1) - seg = seg.NextSegment() - } - } - d.fdRefs.MergeAdjacent(fr) + d.fdRefs.DecRefAndAccount(fr) d.dataMu.Unlock() - } // MapInternal implements platform.File.MapInternal. |