diff options
| -rw-r--r-- | internal/fusefrontend/file.go | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index e374956..3fa5a48 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -6,6 +6,7 @@ import ( "bytes" "fmt" "io" + "log" "os" "sync" "syscall" @@ -21,11 +22,15 @@ import ( // File - based on loopbackFile in go-fuse/fuse/nodefs/files.go type file struct { fd *os.File - + // Has Release() already been called on this file? This also means that the + // wlock entry has been freed, so let's not crash trying to access it. + // Due to concurrency, Release can overtake other operations. These will + // return EBADF in that case. + released bool // fdLock prevents the fd to be closed while we are in the middle of // an operation. // Every FUSE entrypoint should RLock(). The only user of Lock() is - // Release(), which closes the fd, hence has to acquire an exclusive lock. + // Release(), which closes the fd and sets "released" to true. fdLock sync.RWMutex // Was the file opened O_WRONLY? @@ -280,8 +285,9 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) { f.fdLock.RLock() defer f.fdLock.RUnlock() - if f.fd.Fd() < 0 { + if f.released { // The file descriptor has been closed concurrently. + toggledlog.Warn.Printf("ino%d fh%d: Write on released file", f.ino, f.intFd()) return 0, fuse.EBADF } wlock.lock(f.ino) @@ -308,7 +314,11 @@ func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) { // Release - FUSE call, close file func (f *file) Release() { f.fdLock.Lock() + if f.released { + log.Panicf("ino%d fh%d: double release", f.ino, f.intFd()) + } f.fd.Close() + f.released = true f.fdLock.Unlock() wlock.unregister(f.ino) @@ -342,9 +352,9 @@ func (f *file) Fsync(flags int) (code fuse.Status) { func (f *file) Truncate(newSize uint64) fuse.Status { f.fdLock.RLock() defer f.fdLock.RUnlock() - if f.fd.Fd() < 0 { + if f.released { // The file descriptor has been closed concurrently. - toggledlog.Warn.Printf("ino%d fh%d: Truncate on forgotten file", f.ino, f.intFd()) + toggledlog.Warn.Printf("ino%d fh%d: Truncate on released file", f.ino, f.intFd()) return fuse.EBADF } wlock.lock(f.ino) |