diff options
| -rw-r--r-- | pathfs_frontend/compat_darwin.go | 13 | ||||
| -rw-r--r-- | pathfs_frontend/compat_linux.go | 18 | ||||
| -rw-r--r-- | pathfs_frontend/file.go | 15 |
3 files changed, 33 insertions, 13 deletions
diff --git a/pathfs_frontend/compat_darwin.go b/pathfs_frontend/compat_darwin.go new file mode 100644 index 0000000..816ba88 --- /dev/null +++ b/pathfs_frontend/compat_darwin.go @@ -0,0 +1,13 @@ +package pathfs_frontend + +import "syscall" + +// prealloc - preallocate space without changing the file size. This prevents +// us from running out of space in the middle of an operation. +func prealloc(fd int, off int64, len int64) (err error) { + // + // Sorry, fallocate is not available on OSX at all and + // fcntl F_PREALLOCATE is not accessible from Go. + // + // See https://github.com/rfjakob/gocryptfs/issues/18 if you want to help. +} diff --git a/pathfs_frontend/compat_linux.go b/pathfs_frontend/compat_linux.go new file mode 100644 index 0000000..7ed3c74 --- /dev/null +++ b/pathfs_frontend/compat_linux.go @@ -0,0 +1,18 @@ +package pathfs_frontend + +import "syscall" + +// prealloc - preallocate space without changing the file size. This prevents +// us from running out of space in the middle of an operation. +func prealloc(fd int, off int64, len int64) (err error) { + for { + err = syscall.Fallocate(fd, FALLOC_FL_KEEP_SIZE, off, len) + if err == syscall.EINTR { + // fallocate, like many syscalls, can return EINTR. This is not an + // error and just signifies that the operation was interrupted by a + // signal and we should try again. + continue + } + return err + } +} diff --git a/pathfs_frontend/file.go b/pathfs_frontend/file.go index d38a37b..911546d 100644 --- a/pathfs_frontend/file.go +++ b/pathfs_frontend/file.go @@ -99,7 +99,7 @@ func (f *file) createHeader() error { // Prevent partially written (=corrupt) header by preallocating the space beforehand f.fdLock.Lock() defer f.fdLock.Unlock() - err := fallocateRetry(int(f.fd.Fd()), FALLOC_FL_KEEP_SIZE, 0, cryptfs.HEADER_LEN) + err := prealloc(int(f.fd.Fd()), 0, cryptfs.HEADER_LEN) if err != nil { cryptfs.Warn.Printf("createHeader: fallocateRetry failed: %s\n", err.Error()) return err @@ -207,17 +207,6 @@ func (f *file) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fus return fuse.ReadResultData(out), status } -// fallocateRetry - syscall.Fallocate() with retry for EINTR. -func fallocateRetry(fd int, mode uint32, off int64, len int64) (err error) { - for { - err = syscall.Fallocate(fd, mode, off, len) - if err == syscall.EINTR { - continue - } - return err - } -} - const FALLOC_FL_KEEP_SIZE = 0x01 // doWrite - encrypt "data" and write it to plaintext offset "off" @@ -270,7 +259,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { // Prevent partially written (=corrupt) blocks by preallocating the space beforehand f.fdLock.Lock() - err := fallocateRetry(int(f.fd.Fd()), FALLOC_FL_KEEP_SIZE, int64(blockOffset), int64(blockLen)) + err := prealloc(int(f.fd.Fd()), int64(blockOffset), int64(blockLen)) f.fdLock.Unlock() if err != nil { cryptfs.Warn.Printf("doWrite: fallocateRetry failed: %s\n", err.Error()) |