From c9a472c12ff08a6481c086c791f3005e81dbbcf1 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Sun, 3 Jul 2016 17:51:40 +0200 Subject: syscallcompat: move syscall wrapper to their own package We will get more of them as OSX also lacks support for openat. --- internal/fusefrontend/compat_darwin.go | 12 ----------- internal/fusefrontend/compat_linux.go | 35 -------------------------------- internal/fusefrontend/file.go | 5 +++-- internal/syscallcompat/sys_darwin.go | 12 +++++++++++ internal/syscallcompat/sys_linux.go | 37 ++++++++++++++++++++++++++++++++++ 5 files changed, 52 insertions(+), 49 deletions(-) delete mode 100644 internal/fusefrontend/compat_darwin.go delete mode 100644 internal/fusefrontend/compat_linux.go create mode 100644 internal/syscallcompat/sys_darwin.go create mode 100644 internal/syscallcompat/sys_linux.go diff --git a/internal/fusefrontend/compat_darwin.go b/internal/fusefrontend/compat_darwin.go deleted file mode 100644 index 445fb45..0000000 --- a/internal/fusefrontend/compat_darwin.go +++ /dev/null @@ -1,12 +0,0 @@ -package fusefrontend - -// 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. - return nil -} diff --git a/internal/fusefrontend/compat_linux.go b/internal/fusefrontend/compat_linux.go deleted file mode 100644 index 9a8684f..0000000 --- a/internal/fusefrontend/compat_linux.go +++ /dev/null @@ -1,35 +0,0 @@ -package fusefrontend - -import ( - "sync" - "syscall" -) - -import "github.com/rfjakob/gocryptfs/internal/tlog" - -var preallocWarn sync.Once - -// 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 - } - if err == syscall.EOPNOTSUPP { - // ZFS does not support fallocate which caused gocryptfs to abort - // every write operation: https://github.com/rfjakob/gocryptfs/issues/22 - preallocWarn.Do(func() { - tlog.Warn.Printf("Warning: The underlying filesystem " + - "does not support fallocate(2). gocryptfs will continue working " + - "but is no longer resistant against out-of-space errors.\n") - }) - return nil - } - return err - } -} diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index ead253f..f0e0c41 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -16,6 +16,7 @@ import ( "github.com/hanwen/go-fuse/fuse/nodefs" "github.com/rfjakob/gocryptfs/internal/contentenc" + "github.com/rfjakob/gocryptfs/internal/syscallcompat" "github.com/rfjakob/gocryptfs/internal/tlog" ) @@ -100,7 +101,7 @@ func (f *file) createHeader() error { buf := h.Pack() // Prevent partially written (=corrupt) header by preallocating the space beforehand - err := prealloc(int(f.fd.Fd()), 0, contentenc.HEADER_LEN) + err := syscallcompat.Prealloc(int(f.fd.Fd()), 0, contentenc.HEADER_LEN) if err != nil { tlog.Warn.Printf("ino%d: createHeader: prealloc failed: %s\n", f.ino, err.Error()) return err @@ -261,7 +262,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { f.ino, uint64(len(blockData))-f.contentEnc.BlockOverhead(), b.BlockNo) // Prevent partially written (=corrupt) blocks by preallocating the space beforehand - err := prealloc(int(f.fd.Fd()), int64(blockOffset), int64(len(blockData))) + err := syscallcompat.Prealloc(int(f.fd.Fd()), int64(blockOffset), int64(len(blockData))) if err != nil { tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.ino, f.intFd(), err.Error()) status = fuse.ToStatus(err) diff --git a/internal/syscallcompat/sys_darwin.go b/internal/syscallcompat/sys_darwin.go new file mode 100644 index 0000000..d437170 --- /dev/null +++ b/internal/syscallcompat/sys_darwin.go @@ -0,0 +1,12 @@ +package syscallcompat + +// 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. + return nil +} diff --git a/internal/syscallcompat/sys_linux.go b/internal/syscallcompat/sys_linux.go new file mode 100644 index 0000000..9fe9da5 --- /dev/null +++ b/internal/syscallcompat/sys_linux.go @@ -0,0 +1,37 @@ +package syscallcompat + +import ( + "sync" + "syscall" + + "github.com/rfjakob/gocryptfs/internal/tlog" +) + +const FALLOC_FL_KEEP_SIZE = 0x01 + +var preallocWarn sync.Once + +// 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 + } + if err == syscall.EOPNOTSUPP { + // ZFS does not support fallocate which caused gocryptfs to abort + // every write operation: https://github.com/rfjakob/gocryptfs/issues/22 + preallocWarn.Do(func() { + tlog.Warn.Printf("Warning: The underlying filesystem " + + "does not support fallocate(2). gocryptfs will continue working " + + "but is no longer resistant against out-of-space errors.\n") + }) + return nil + } + return err + } +} -- cgit v1.2.3