diff options
Diffstat (limited to 'pkg/sentry/fsimpl/gofer')
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/filesystem.go | 57 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/gofer.go | 110 |
2 files changed, 126 insertions, 41 deletions
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go index 8f95473b6..c34451269 100644 --- a/pkg/sentry/fsimpl/gofer/filesystem.go +++ b/pkg/sentry/fsimpl/gofer/filesystem.go @@ -15,7 +15,9 @@ package gofer import ( + "fmt" "math" + "strings" "sync" "sync/atomic" @@ -1608,3 +1610,58 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe defer fs.renameMu.RUnlock() return genericPrependPath(vfsroot, vd.Mount(), vd.Dentry().Impl().(*dentry), b) } + +type mopt struct { + key string + value interface{} +} + +func (m mopt) String() string { + if m.value == nil { + return fmt.Sprintf("%s", m.key) + } + return fmt.Sprintf("%s=%v", m.key, m.value) +} + +// MountOptions implements vfs.FilesystemImpl.MountOptions. +func (fs *filesystem) MountOptions() string { + optsKV := []mopt{ + {moptTransport, transportModeFD}, // Only valid value, currently. + {moptReadFD, fs.opts.fd}, // Currently, read and write FD are the same. + {moptWriteFD, fs.opts.fd}, // Currently, read and write FD are the same. + {moptAname, fs.opts.aname}, + {moptDfltUID, fs.opts.dfltuid}, + {moptDfltGID, fs.opts.dfltgid}, + {moptMsize, fs.opts.msize}, + {moptVersion, fs.opts.version}, + {moptDentryCacheLimit, fs.opts.maxCachedDentries}, + } + + switch fs.opts.interop { + case InteropModeExclusive: + optsKV = append(optsKV, mopt{moptCache, cacheFSCache}) + case InteropModeWritethrough: + optsKV = append(optsKV, mopt{moptCache, cacheFSCacheWritethrough}) + case InteropModeShared: + if fs.opts.regularFilesUseSpecialFileFD { + optsKV = append(optsKV, mopt{moptCache, cacheNone}) + } else { + optsKV = append(optsKV, mopt{moptCache, cacheRemoteRevalidating}) + } + } + if fs.opts.forcePageCache { + optsKV = append(optsKV, mopt{moptForcePageCache, nil}) + } + if fs.opts.limitHostFDTranslation { + optsKV = append(optsKV, mopt{moptLimitHostFDTranslation, nil}) + } + if fs.opts.overlayfsStaleRead { + optsKV = append(optsKV, mopt{moptOverlayfsStaleRead, nil}) + } + + opts := make([]string, 0, len(optsKV)) + for _, opt := range optsKV { + opts = append(opts, opt.String()) + } + return strings.Join(opts, ",") +} diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index 1508cbdf1..71569dc65 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -66,6 +66,34 @@ import ( // Name is the default filesystem name. const Name = "9p" +// Mount option names for goferfs. +const ( + moptTransport = "trans" + moptReadFD = "rfdno" + moptWriteFD = "wfdno" + moptAname = "aname" + moptDfltUID = "dfltuid" + moptDfltGID = "dfltgid" + moptMsize = "msize" + moptVersion = "version" + moptDentryCacheLimit = "dentry_cache_limit" + moptCache = "cache" + moptForcePageCache = "force_page_cache" + moptLimitHostFDTranslation = "limit_host_fd_translation" + moptOverlayfsStaleRead = "overlayfs_stale_read" +) + +// Valid values for the "cache" mount option. +const ( + cacheNone = "none" + cacheFSCache = "fscache" + cacheFSCacheWritethrough = "fscache_writethrough" + cacheRemoteRevalidating = "remote_revalidating" +) + +// Valid values for "trans" mount option. +const transportModeFD = "fd" + // FilesystemType implements vfs.FilesystemType. // // +stateify savable @@ -301,39 +329,39 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt // Get the attach name. fsopts.aname = "/" - if aname, ok := mopts["aname"]; ok { - delete(mopts, "aname") + if aname, ok := mopts[moptAname]; ok { + delete(mopts, moptAname) fsopts.aname = aname } // Parse the cache policy. For historical reasons, this defaults to the // least generally-applicable option, InteropModeExclusive. fsopts.interop = InteropModeExclusive - if cache, ok := mopts["cache"]; ok { - delete(mopts, "cache") + if cache, ok := mopts[moptCache]; ok { + delete(mopts, moptCache) switch cache { - case "fscache": + case cacheFSCache: fsopts.interop = InteropModeExclusive - case "fscache_writethrough": + case cacheFSCacheWritethrough: fsopts.interop = InteropModeWritethrough - case "none": + case cacheNone: fsopts.regularFilesUseSpecialFileFD = true fallthrough - case "remote_revalidating": + case cacheRemoteRevalidating: fsopts.interop = InteropModeShared default: - ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid cache policy: cache=%s", cache) + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid cache policy: %s=%s", moptCache, cache) return nil, nil, syserror.EINVAL } } // Parse the default UID and GID. fsopts.dfltuid = _V9FS_DEFUID - if dfltuidstr, ok := mopts["dfltuid"]; ok { - delete(mopts, "dfltuid") + if dfltuidstr, ok := mopts[moptDfltUID]; ok { + delete(mopts, moptDfltUID) dfltuid, err := strconv.ParseUint(dfltuidstr, 10, 32) if err != nil { - ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: dfltuid=%s", dfltuidstr) + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: %s=%s", moptDfltUID, dfltuidstr) return nil, nil, syserror.EINVAL } // In Linux, dfltuid is interpreted as a UID and is converted to a KUID @@ -342,11 +370,11 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fsopts.dfltuid = auth.KUID(dfltuid) } fsopts.dfltgid = _V9FS_DEFGID - if dfltgidstr, ok := mopts["dfltgid"]; ok { - delete(mopts, "dfltgid") + if dfltgidstr, ok := mopts[moptDfltGID]; ok { + delete(mopts, moptDfltGID) dfltgid, err := strconv.ParseUint(dfltgidstr, 10, 32) if err != nil { - ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: dfltgid=%s", dfltgidstr) + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid default UID: %s=%s", moptDfltGID, dfltgidstr) return nil, nil, syserror.EINVAL } fsopts.dfltgid = auth.KGID(dfltgid) @@ -354,11 +382,11 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt // 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 { - delete(mopts, "msize") + if msizestr, ok := mopts[moptMsize]; ok { + delete(mopts, moptMsize) msize, err := strconv.ParseUint(msizestr, 10, 32) if err != nil { - ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid message size: msize=%s", msizestr) + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid message size: %s=%s", moptMsize, msizestr) return nil, nil, syserror.EINVAL } fsopts.msize = uint32(msize) @@ -366,34 +394,34 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt // Parse the 9P protocol version. fsopts.version = p9.HighestVersionString() - if version, ok := mopts["version"]; ok { - delete(mopts, "version") + if version, ok := mopts[moptVersion]; ok { + delete(mopts, moptVersion) fsopts.version = version } // Parse the dentry cache limit. fsopts.maxCachedDentries = 1000 - if str, ok := mopts["dentry_cache_limit"]; ok { - delete(mopts, "dentry_cache_limit") + if str, ok := mopts[moptDentryCacheLimit]; ok { + delete(mopts, moptDentryCacheLimit) maxCachedDentries, err := strconv.ParseUint(str, 10, 64) if err != nil { - ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid dentry cache limit: dentry_cache_limit=%s", str) + ctx.Warningf("gofer.FilesystemType.GetFilesystem: invalid dentry cache limit: %s=%s", moptDentryCacheLimit, str) return nil, nil, syserror.EINVAL } fsopts.maxCachedDentries = maxCachedDentries } // Handle simple flags. - if _, ok := mopts["force_page_cache"]; ok { - delete(mopts, "force_page_cache") + if _, ok := mopts[moptForcePageCache]; ok { + delete(mopts, moptForcePageCache) fsopts.forcePageCache = true } - if _, ok := mopts["limit_host_fd_translation"]; ok { - delete(mopts, "limit_host_fd_translation") + if _, ok := mopts[moptLimitHostFDTranslation]; ok { + delete(mopts, moptLimitHostFDTranslation) fsopts.limitHostFDTranslation = true } - if _, ok := mopts["overlayfs_stale_read"]; ok { - delete(mopts, "overlayfs_stale_read") + if _, ok := mopts[moptOverlayfsStaleRead]; ok { + delete(mopts, moptOverlayfsStaleRead) fsopts.overlayfsStaleRead = true } // fsopts.regularFilesUseSpecialFileFD can only be enabled by specifying @@ -469,34 +497,34 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt func getFDFromMountOptionsMap(ctx context.Context, mopts map[string]string) (int, error) { // Check that the transport is "fd". - trans, ok := mopts["trans"] - if !ok || trans != "fd" { - ctx.Warningf("gofer.getFDFromMountOptionsMap: transport must be specified as 'trans=fd'") + trans, ok := mopts[moptTransport] + if !ok || trans != transportModeFD { + ctx.Warningf("gofer.getFDFromMountOptionsMap: transport must be specified as '%s=%s'", moptTransport, transportModeFD) return -1, syserror.EINVAL } - delete(mopts, "trans") + delete(mopts, moptTransport) // Check that read and write FDs are provided and identical. - rfdstr, ok := mopts["rfdno"] + rfdstr, ok := mopts[moptReadFD] if !ok { - ctx.Warningf("gofer.getFDFromMountOptionsMap: read FD must be specified as 'rfdno=<file descriptor>'") + ctx.Warningf("gofer.getFDFromMountOptionsMap: read FD must be specified as '%s=<file descriptor>'", moptReadFD) return -1, syserror.EINVAL } - delete(mopts, "rfdno") + delete(mopts, moptReadFD) rfd, err := strconv.Atoi(rfdstr) if err != nil { - ctx.Warningf("gofer.getFDFromMountOptionsMap: invalid read FD: rfdno=%s", rfdstr) + ctx.Warningf("gofer.getFDFromMountOptionsMap: invalid read FD: %s=%s", moptReadFD, rfdstr) return -1, syserror.EINVAL } - wfdstr, ok := mopts["wfdno"] + wfdstr, ok := mopts[moptWriteFD] if !ok { - ctx.Warningf("gofer.getFDFromMountOptionsMap: write FD must be specified as 'wfdno=<file descriptor>'") + ctx.Warningf("gofer.getFDFromMountOptionsMap: write FD must be specified as '%s=<file descriptor>'", moptWriteFD) return -1, syserror.EINVAL } - delete(mopts, "wfdno") + delete(mopts, moptWriteFD) wfd, err := strconv.Atoi(wfdstr) if err != nil { - ctx.Warningf("gofer.getFDFromMountOptionsMap: invalid write FD: wfdno=%s", wfdstr) + ctx.Warningf("gofer.getFDFromMountOptionsMap: invalid write FD: %s=%s", moptWriteFD, wfdstr) return -1, syserror.EINVAL } if rfd != wfd { |