diff options
| -rw-r--r-- | pkg/p9/file.go | 2 | ||||
| -rw-r--r-- | pkg/p9/p9.go | 37 | ||||
| -rw-r--r-- | runsc/fsgofer/fsgofer.go | 13 |
3 files changed, 32 insertions, 20 deletions
diff --git a/pkg/p9/file.go b/pkg/p9/file.go index 907445e15..96d1f2a8e 100644 --- a/pkg/p9/file.go +++ b/pkg/p9/file.go @@ -116,7 +116,7 @@ type File interface { // N.B. The server must resolve any lazy paths when open is called. // After this point, read and write may be called on files with no // deletion check, so resolving in the data path is not viable. - Open(mode OpenFlags) (*fd.FD, QID, uint32, error) + Open(flags OpenFlags) (*fd.FD, QID, uint32, error) // Read reads from this file. Open must be called first. // diff --git a/pkg/p9/p9.go b/pkg/p9/p9.go index 6039f5a42..415200d60 100644 --- a/pkg/p9/p9.go +++ b/pkg/p9/p9.go @@ -32,18 +32,22 @@ import ( type OpenFlags uint32 const ( - // ReadOnly is a Topen and Tcreate flag indicating read-only mode. + // ReadOnly is a Tlopen and Tlcreate flag indicating read-only mode. ReadOnly OpenFlags = 0 - // WriteOnly is a Topen and Tcreate flag indicating write-only mode. + // WriteOnly is a Tlopen and Tlcreate flag indicating write-only mode. WriteOnly OpenFlags = 1 - // ReadWrite is a Topen flag indicates read-write mode. + // ReadWrite is a Tlopen flag indicates read-write mode. ReadWrite OpenFlags = 2 // OpenFlagsModeMask is a mask of valid OpenFlags mode bits. OpenFlagsModeMask OpenFlags = 3 + // OpenTruncate is a Tlopen flag indicating that the opened file should be + // truncated. + OpenTruncate OpenFlags = 01000 + // OpenFlagsIgnoreMask is a list of OpenFlags mode bits that are ignored for Tlopen. // Note that syscall.O_LARGEFILE is set to zero, use value from Linux fcntl.h. OpenFlagsIgnoreMask OpenFlags = syscall.O_DIRECTORY | syscall.O_NOATIME | 0100000 @@ -71,25 +75,32 @@ const ( // OSFlags converts a p9.OpenFlags to an int compatible with open(2). func (o OpenFlags) OSFlags() int { - return int(o & OpenFlagsModeMask) + // "flags contains Linux open(2) flags bits" - 9P2000.L + return int(o) } // String implements fmt.Stringer. func (o OpenFlags) String() string { - switch o { + var buf strings.Builder + switch mode := o & OpenFlagsModeMask; mode { case ReadOnly: - return "ReadOnly" + buf.WriteString("ReadOnly") case WriteOnly: - return "WriteOnly" + buf.WriteString("WriteOnly") case ReadWrite: - return "ReadWrite" - case OpenFlagsModeMask: - return "OpenFlagsModeMask" - case OpenFlagsIgnoreMask: - return "OpenFlagsIgnoreMask" + buf.WriteString("ReadWrite") default: - return "UNDEFINED" + fmt.Fprintf(&buf, "%#o", mode) + } + otherFlags := o &^ OpenFlagsModeMask + if otherFlags&OpenTruncate != 0 { + buf.WriteString("|OpenTruncate") + otherFlags &^= OpenTruncate + } + if otherFlags != 0 { + fmt.Fprintf(&buf, "|%#o", otherFlags) } + return buf.String() } // Tag is a message tag. diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go index 18b853e2e..9117d9616 100644 --- a/runsc/fsgofer/fsgofer.go +++ b/runsc/fsgofer/fsgofer.go @@ -366,23 +366,24 @@ func fchown(fd int, uid p9.UID, gid p9.GID) error { } // Open implements p9.File. -func (l *localFile) Open(mode p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) { +func (l *localFile) Open(flags p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) { if l.isOpen() { panic(fmt.Sprintf("attempting to open already opened file: %q", l.hostPath)) } // Check if control file can be used or if a new open must be created. var newFile *fd.FD - if mode == p9.ReadOnly { - log.Debugf("Open reusing control file, mode: %v, %q", mode, l.hostPath) + if flags == p9.ReadOnly { + log.Debugf("Open reusing control file, flags: %v, %q", flags, l.hostPath) newFile = l.file } else { // Ideally reopen would call name_to_handle_at (with empty name) and // open_by_handle_at to reopen the file without using 'hostPath'. However, // name_to_handle_at and open_by_handle_at aren't supported by overlay2. - log.Debugf("Open reopening file, mode: %v, %q", mode, l.hostPath) + log.Debugf("Open reopening file, flags: %v, %q", flags, l.hostPath) var err error - newFile, err = reopenProcFd(l.file, openFlags|mode.OSFlags()) + // Constrain open flags to the open mode and O_TRUNC. + newFile, err = reopenProcFd(l.file, openFlags|(flags.OSFlags()&(syscall.O_ACCMODE|syscall.O_TRUNC))) if err != nil { return nil, p9.QID{}, 0, extractErrno(err) } @@ -409,7 +410,7 @@ func (l *localFile) Open(mode p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) { } l.file = newFile } - l.mode = mode + l.mode = flags & p9.OpenFlagsModeMask return fd, l.attachPoint.makeQID(stat), 0, nil } |