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Make sure we mark the libdevmapper /dev/mapper/control fd CLOEXEC

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We do a hack to mark it such, because otherwise lxc-start will not
work.
This commit is contained in:
Alexander Larsson 2013-10-03 21:00:16 +02:00
parent 7b58e15b08
commit 1a1be5a87c
1 changed files with 21 additions and 0 deletions
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21
devmapper/deviceset_devmapper.go
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@ -10,6 +10,7 @@ import (
"os/exec" "os/exec"
"path" "path"
"path/filepath" "path/filepath"
"strconv"
"strings" "strings"
"syscall" "syscall"
) )
@ -564,6 +565,21 @@ func (devices *DeviceSetDM) setupBaseImage() error {
return nil return nil
} }
func setCloseOnExec(name string) {
fileInfos, _ := ioutil.ReadDir("/proc/self/fd")
if fileInfos != nil {
for _, i := range fileInfos {
link, _ := os.Readlink(filepath.Join("/proc/self/fd", i.Name()))
if link == name {
fd, err := strconv.Atoi(i.Name())
if err == nil {
syscall.CloseOnExec(fd)
}
}
}
}
}
func (devices *DeviceSetDM) initDevmapper() error { func (devices *DeviceSetDM) initDevmapper() error {
info, err := devices.getInfo(devices.getPoolName()) info, err := devices.getInfo(devices.getPoolName())
if info == nil { if info == nil {
@ -572,6 +588,11 @@ func (devices *DeviceSetDM) initDevmapper() error {
} }
utils.Debugf("initDevmapper(). Pool exists: %v", info.Exists) utils.Debugf("initDevmapper(). Pool exists: %v", info.Exists)
// It seems libdevmapper opens this without O_CLOEXEC, and go exec will not close files
// that are not Close-on-exec, and lxc-start will die if it inherits any unexpected files,
// so we add this badhack to make sure it closes itself
setCloseOnExec("/dev/mapper/control")
if info.Exists != 0 { if info.Exists != 0 {
/* Pool exists, assume everything is up */ /* Pool exists, assume everything is up */
if err := devices.loadMetaData(); err != nil { if err := devices.loadMetaData(); err != nil {