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Diffstat (limited to 'runsc/fsgofer/fsgofer.go')
-rw-r--r--runsc/fsgofer/fsgofer.go97
1 files changed, 60 insertions, 37 deletions
diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go
index 0b628c8ce..c3bba0973 100644
--- a/runsc/fsgofer/fsgofer.go
+++ b/runsc/fsgofer/fsgofer.go
@@ -49,6 +49,21 @@ const (
allowedOpenFlags = unix.O_TRUNC
)
+var (
+ // Remember the process uid/gid to skip chown calls when file owner/group
+ // doesn't need to be changed.
+ processUID = p9.UID(os.Getuid())
+ processGID = p9.GID(os.Getgid())
+)
+
+// join is equivalent to path.Join() but skips path.Clean() which is expensive.
+func join(parent, child string) string {
+ if child == "." || child == ".." {
+ panic(fmt.Sprintf("invalid child path %q", child))
+ }
+ return parent + "/" + child
+}
+
// Config sets configuration options for each attach point.
type Config struct {
// ROMount is set to true if this is a readonly mount.
@@ -115,7 +130,7 @@ func (a *attachPoint) Attach() (p9.File, error) {
return nil, fmt.Errorf("unable to stat %q: %v", a.prefix, err)
}
- lf, err := newLocalFile(a, f, a.prefix, readable, stat)
+ lf, err := newLocalFile(a, f, a.prefix, readable, &stat)
if err != nil {
return nil, fmt.Errorf("unable to create localFile %q: %v", a.prefix, err)
}
@@ -124,7 +139,7 @@ func (a *attachPoint) Attach() (p9.File, error) {
}
// makeQID returns a unique QID for the given stat buffer.
-func (a *attachPoint) makeQID(stat unix.Stat_t) p9.QID {
+func (a *attachPoint) makeQID(stat *unix.Stat_t) p9.QID {
a.deviceMu.Lock()
defer a.deviceMu.Unlock()
@@ -245,7 +260,7 @@ func reopenProcFd(f *fd.FD, mode int) (*fd.FD, error) {
}
func openAnyFileFromParent(parent *localFile, name string) (*fd.FD, string, bool, error) {
- pathDebug := path.Join(parent.hostPath, name)
+ pathDebug := join(parent.hostPath, name)
f, readable, err := openAnyFile(pathDebug, func(mode int) (*fd.FD, error) {
return fd.OpenAt(parent.file, name, openFlags|mode, 0)
})
@@ -297,8 +312,8 @@ func openAnyFile(pathDebug string, fn func(mode int) (*fd.FD, error)) (*fd.FD, b
return nil, false, extractErrno(err)
}
-func checkSupportedFileType(stat unix.Stat_t, permitSocket bool) error {
- switch stat.Mode & unix.S_IFMT {
+func checkSupportedFileType(mode uint32, permitSocket bool) error {
+ switch mode & unix.S_IFMT {
case unix.S_IFREG, unix.S_IFDIR, unix.S_IFLNK:
return nil
@@ -313,8 +328,8 @@ func checkSupportedFileType(stat unix.Stat_t, permitSocket bool) error {
}
}
-func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat unix.Stat_t) (*localFile, error) {
- if err := checkSupportedFileType(stat, a.conf.HostUDS); err != nil {
+func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat *unix.Stat_t) (*localFile, error) {
+ if err := checkSupportedFileType(stat.Mode, a.conf.HostUDS); err != nil {
return nil, err
}
@@ -442,8 +457,10 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
})
defer cu.Clean()
- if err := fchown(child.FD(), uid, gid); err != nil {
- return nil, nil, p9.QID{}, 0, extractErrno(err)
+ if uid != processUID || gid != processGID {
+ if err := fchown(child.FD(), uid, gid); err != nil {
+ return nil, nil, p9.QID{}, 0, extractErrno(err)
+ }
}
stat, err := fstat(child.FD())
if err != nil {
@@ -452,11 +469,11 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
c := &localFile{
attachPoint: l.attachPoint,
- hostPath: path.Join(l.hostPath, name),
+ hostPath: join(l.hostPath, name),
file: child,
mode: mode,
fileType: unix.S_IFREG,
- qid: l.attachPoint.makeQID(stat),
+ qid: l.attachPoint.makeQID(&stat),
}
cu.Release()
@@ -488,8 +505,10 @@ func (l *localFile) Mkdir(name string, perm p9.FileMode, uid p9.UID, gid p9.GID)
}
defer f.Close()
- if err := fchown(f.FD(), uid, gid); err != nil {
- return p9.QID{}, extractErrno(err)
+ if uid != processUID || gid != processGID {
+ if err := fchown(f.FD(), uid, gid); err != nil {
+ return p9.QID{}, extractErrno(err)
+ }
}
stat, err := fstat(f.FD())
if err != nil {
@@ -497,7 +516,7 @@ func (l *localFile) Mkdir(name string, perm p9.FileMode, uid p9.UID, gid p9.GID)
}
cu.Release()
- return l.attachPoint.makeQID(stat), nil
+ return l.attachPoint.makeQID(&stat), nil
}
// Walk implements p9.File.
@@ -512,7 +531,7 @@ func (l *localFile) WalkGetAttr(names []string) ([]p9.QID, p9.File, p9.AttrMask,
if err != nil {
return nil, nil, p9.AttrMask{}, p9.Attr{}, err
}
- mask, attr := l.fillAttr(stat)
+ mask, attr := l.fillAttr(&stat)
return qids, file, mask, attr, nil
}
@@ -538,13 +557,13 @@ func (l *localFile) walk(names []string) ([]p9.QID, p9.File, unix.Stat_t, error)
file: newFile,
mode: invalidMode,
fileType: l.fileType,
- qid: l.attachPoint.makeQID(stat),
+ qid: l.attachPoint.makeQID(&stat),
controlReadable: readable,
}
return []p9.QID{c.qid}, c, stat, nil
}
- var qids []p9.QID
+ qids := make([]p9.QID, 0, len(names))
var lastStat unix.Stat_t
last := l
for _, name := range names {
@@ -560,7 +579,7 @@ func (l *localFile) walk(names []string) ([]p9.QID, p9.File, unix.Stat_t, error)
_ = f.Close()
return nil, nil, unix.Stat_t{}, extractErrno(err)
}
- c, err := newLocalFile(last.attachPoint, f, path, readable, lastStat)
+ c, err := newLocalFile(last.attachPoint, f, path, readable, &lastStat)
if err != nil {
_ = f.Close()
return nil, nil, unix.Stat_t{}, extractErrno(err)
@@ -609,11 +628,11 @@ func (l *localFile) GetAttr(_ p9.AttrMask) (p9.QID, p9.AttrMask, p9.Attr, error)
if err != nil {
return p9.QID{}, p9.AttrMask{}, p9.Attr{}, extractErrno(err)
}
- mask, attr := l.fillAttr(stat)
+ mask, attr := l.fillAttr(&stat)
return l.qid, mask, attr, nil
}
-func (l *localFile) fillAttr(stat unix.Stat_t) (p9.AttrMask, p9.Attr) {
+func (l *localFile) fillAttr(stat *unix.Stat_t) (p9.AttrMask, p9.Attr) {
attr := p9.Attr{
Mode: p9.FileMode(stat.Mode),
UID: p9.UID(stat.Uid),
@@ -739,15 +758,15 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
// utimensat operates different that other syscalls. To operate on a
// symlink it *requires* AT_SYMLINK_NOFOLLOW with dirFD and a non-empty
// name.
- parent, err := unix.Open(path.Dir(l.hostPath), openFlags|unix.O_PATH, 0)
- if err != nil {
- return extractErrno(err)
+ parent, oErr := unix.Open(path.Dir(l.hostPath), openFlags|unix.O_PATH, 0)
+ if oErr != nil {
+ return extractErrno(oErr)
}
defer unix.Close(parent)
- if terr := utimensat(parent, path.Base(l.hostPath), utimes, linux.AT_SYMLINK_NOFOLLOW); terr != nil {
- log.Debugf("SetAttr utimens failed %q, err: %v", l.hostPath, terr)
- err = extractErrno(terr)
+ if tErr := utimensat(parent, path.Base(l.hostPath), utimes, linux.AT_SYMLINK_NOFOLLOW); tErr != nil {
+ log.Debugf("SetAttr utimens failed %q, err: %v", l.hostPath, tErr)
+ err = extractErrno(tErr)
}
} else {
// Directories and regular files can operate directly on the fd
@@ -768,9 +787,9 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
if valid.GID {
gid = int(attr.GID)
}
- if oerr := unix.Fchownat(f.FD(), "", uid, gid, linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW); oerr != nil {
- log.Debugf("SetAttr fchownat failed %q, err: %v", l.hostPath, oerr)
- err = extractErrno(oerr)
+ if oErr := unix.Fchownat(f.FD(), "", uid, gid, linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW); oErr != nil {
+ log.Debugf("SetAttr fchownat failed %q, err: %v", l.hostPath, oErr)
+ err = extractErrno(oErr)
}
}
@@ -881,8 +900,10 @@ func (l *localFile) Symlink(target, newName string, uid p9.UID, gid p9.GID) (p9.
}
defer f.Close()
- if err := fchown(f.FD(), uid, gid); err != nil {
- return p9.QID{}, extractErrno(err)
+ if uid != processUID || gid != processGID {
+ if err := fchown(f.FD(), uid, gid); err != nil {
+ return p9.QID{}, extractErrno(err)
+ }
}
stat, err := fstat(f.FD())
if err != nil {
@@ -890,7 +911,7 @@ func (l *localFile) Symlink(target, newName string, uid p9.UID, gid p9.GID) (p9.
}
cu.Release()
- return l.attachPoint.makeQID(stat), nil
+ return l.attachPoint.makeQID(&stat), nil
}
// Link implements p9.File.
@@ -938,8 +959,10 @@ func (l *localFile) Mknod(name string, mode p9.FileMode, _ uint32, _ uint32, uid
}
defer child.Close()
- if err := fchown(child.FD(), uid, gid); err != nil {
- return p9.QID{}, extractErrno(err)
+ if uid != processUID || gid != processGID {
+ if err := fchown(child.FD(), uid, gid); err != nil {
+ return p9.QID{}, extractErrno(err)
+ }
}
stat, err := fstat(child.FD())
if err != nil {
@@ -947,7 +970,7 @@ func (l *localFile) Mknod(name string, mode p9.FileMode, _ uint32, _ uint32, uid
}
cu.Release()
- return l.attachPoint.makeQID(stat), nil
+ return l.attachPoint.makeQID(&stat), nil
}
// UnlinkAt implements p9.File.
@@ -1045,7 +1068,7 @@ func (l *localFile) readDirent(f int, offset uint64, count uint32, skip uint64)
log.Warningf("Readdir is skipping file with failed stat %q, err: %v", l.hostPath, err)
continue
}
- qid := l.attachPoint.makeQID(stat)
+ qid := l.attachPoint.makeQID(&stat)
offset++
dirents = append(dirents, p9.Dirent{
QID: qid,
@@ -1139,7 +1162,7 @@ func (l *localFile) isOpen() bool {
// Renamed implements p9.Renamed.
func (l *localFile) Renamed(newDir p9.File, newName string) {
- l.hostPath = path.Join(newDir.(*localFile).hostPath, newName)
+ l.hostPath = join(newDir.(*localFile).hostPath, newName)
}
// extractErrno tries to determine the errno.
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-24 17:05:56 +0000