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authorJakob Unterwurzacher2016-07-03 20:05:32 +0200
committerJakob Unterwurzacher2016-07-03 20:05:32 +0200
commit79851bf6cc391f1150be387631159d553d5426f3 (patch)
tree560f3228054ad8a5a37500de5aa21832c021a03e /internal/syscallcompat
parent9b725c15cf50cfb85ec6ec88c47843092775dedc (diff)
syscallcompat: OSX: add Renamat wrapper
Adds a poor man's renameat implementation for OSX.
Diffstat (limited to 'internal/syscallcompat')
-rw-r--r--internal/syscallcompat/sys_darwin.go91
-rw-r--r--internal/syscallcompat/sys_linux.go8
2 files changed, 73 insertions, 26 deletions
diff --git a/internal/syscallcompat/sys_darwin.go b/internal/syscallcompat/sys_darwin.go
index 81e1b15..7d39484 100644
--- a/internal/syscallcompat/sys_darwin.go
+++ b/internal/syscallcompat/sys_darwin.go
@@ -2,44 +2,87 @@ package syscallcompat
import (
"os"
+ "path/filepath"
"sync"
"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.
+// 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.
+func EnospcPrealloc(fd int, off int64, len int64) (err error) {
return nil
}
-var openatLock sync.Mutex
+// See above.
+func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
+ return syscall.EOPNOTSUPP
+}
-// Poor man's Openat:
-// 1) fchdir to the dirfd
-// 2) open the file
-// 3) chdir back.
+var chdirMutex sync.Mutex
+
+// Poor man's Openat
func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {
- openatLock.Lock()
- defer openatLock.Unlock()
+ chdirMutex.Lock()
+ defer chdirMutex.Unlock()
+ if !filepath.IsAbs(path) {
+ // Save the old working directory
+ oldWd, err := os.Getwd()
+ if err != nil {
+ return -1, err
+ }
+ // Chdir to target directory
+ err = syscall.Fchdir(dirfd)
+ if err != nil {
+ return -1, err
+ }
+ // Chdir back at the end
+ defer os.Chdir(oldWd)
+ }
+ return syscall.Open(path, flags, mode)
+}
- oldWd, err := os.Getwd()
+// Poor man's Renameat
+func Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error) {
+ chdirMutex.Lock()
+ defer chdirMutex.Unlock()
+ // Unless both paths are absolute we have to save the old working dir and
+ // Chdir(oldWd) back to it in the end. If we error out before the first
+ // chdir, Chdir(oldWd) is unneccassary but does no harm.
+ if !filepath.IsAbs(oldpath) || !filepath.IsAbs(newpath) {
+ oldWd, err := os.Getwd()
+ if err != nil {
+ return err
+ }
+ defer os.Chdir(oldWd)
+ }
+ // Make oldpath absolute
+ oldpath, err = dirfdAbs(olddirfd, oldpath)
if err != nil {
- return -1, err
+ return err
}
- err = syscall.Fchdir(dirfd)
+ // Make newpath absolute
+ newpath, err = dirfdAbs(newdirfd, newpath)
if err != nil {
- return -1, err
+ return err
}
- defer os.Chdir(oldWd)
-
- return syscall.Open(path, flags, mode)
+ return syscall.Rename(oldpath, newpath)
}
-func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
- return syscall.EOPNOTSUPP
+// dirfdAbs transforms the dirfd-relative "path" to an absolute one. If the
+// path is not already absolute, this function will change the working
+// directory. The caller has to chdir back.
+func dirfdAbs(dirfd int, path string) (absPath string, err error) {
+ if filepath.IsAbs(path) {
+ return path, nil
+ }
+ err = syscall.Fchdir(dirfd)
+ if err != nil {
+ return "", err
+ }
+ wd, err := os.Getwd()
+ if err != nil {
+ return "", err
+ }
+ return filepath.Join(wd, path), nil
}
diff --git a/internal/syscallcompat/sys_linux.go b/internal/syscallcompat/sys_linux.go
index ca6df95..e12d100 100644
--- a/internal/syscallcompat/sys_linux.go
+++ b/internal/syscallcompat/sys_linux.go
@@ -37,10 +37,14 @@ func EnospcPrealloc(fd int, off int64, len int64) (err error) {
}
}
+func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
+ return syscall.Fallocate(fd, mode, off, len)
+}
+
func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {
return syscall.Openat(dirfd, path, flags, mode)
}
-func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
- return syscall.Fallocate(fd, mode, off, len)
+func Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error) {
+ return syscall.Renameat(olddirfd, oldpath, newdirfd, newpath)
}