Merge "libdm: Implement GetDmDevicePathByName()."
diff --git a/fs_mgr/libdm/dm.cpp b/fs_mgr/libdm/dm.cpp
index 8bd3b9d..b96f4c1 100644
--- a/fs_mgr/libdm/dm.cpp
+++ b/fs_mgr/libdm/dm.cpp
@@ -17,6 +17,7 @@
#include "libdm/dm.h"
#include <sys/ioctl.h>
+#include <sys/sysmacros.h>
#include <sys/types.h>
#include <android-base/macros.h>
@@ -258,8 +259,17 @@
// Accepts a device mapper device name (like system_a, vendor_b etc) and
// returns the path to it's device node (or symlink to the device node)
-std::string DeviceMapper::GetDmDevicePathByName(const std::string& /* name */) {
- return "";
+bool DeviceMapper::GetDmDevicePathByName(const std::string& name, std::string* path) {
+ struct dm_ioctl io;
+ InitIo(&io, name);
+ if (ioctl(fd_, DM_DEV_STATUS, &io) < 0) {
+ PLOG(ERROR) << "DM_DEV_STATUS failed for " << name;
+ return false;
+ }
+
+ uint32_t dev_num = minor(io.dev);
+ *path = "/dev/block/dm-" + std::to_string(dev_num);
+ return true;
}
// private methods of DeviceMapper
diff --git a/fs_mgr/libdm/include/libdm/dm.h b/fs_mgr/libdm/include/libdm/dm.h
index 8d23b2c..60bceed 100644
--- a/fs_mgr/libdm/include/libdm/dm.h
+++ b/fs_mgr/libdm/include/libdm/dm.h
@@ -104,8 +104,9 @@
bool GetAvailableDevices(std::vector<DmBlockDevice>* devices);
// Returns the path to the device mapper device node in '/dev' corresponding to
- // 'name'.
- std::string GetDmDevicePathByName(const std::string& name);
+ // 'name'. If the device does not exist, false is returned, and the path
+ // parameter is not set.
+ bool GetDmDevicePathByName(const std::string& name, std::string* path);
// The only way to create a DeviceMapper object.
static DeviceMapper& Instance();
diff --git a/fs_mgr/tools/dmctl.cpp b/fs_mgr/tools/dmctl.cpp
index c15173f..9d48b8c 100644
--- a/fs_mgr/tools/dmctl.cpp
+++ b/fs_mgr/tools/dmctl.cpp
@@ -49,6 +49,7 @@
std::cerr << " create <dm-name> [-ro] <targets...>" << std::endl;
std::cerr << " delete <dm-name>" << std::endl;
std::cerr << " list <devices | targets>" << std::endl;
+ std::cerr << " getpath <dm-name>" << std::endl;
std::cerr << " help" << std::endl;
std::cerr << std::endl;
std::cerr << "Target syntax:" << std::endl;
@@ -241,11 +242,30 @@
return 0;
}
+static int GetPathCmdHandler(int argc, char** argv) {
+ if (argc != 1) {
+ std::cerr << "Invalid arguments, see \'dmctl help\'" << std::endl;
+ return -EINVAL;
+ }
+
+ DeviceMapper& dm = DeviceMapper::Instance();
+ std::string path;
+ if (!dm.GetDmDevicePathByName(argv[0], &path)) {
+ std::cerr << "Could not query path of device \"" << argv[0] << "\"." << std::endl;
+ return -EINVAL;
+ }
+ std::cout << path << std::endl;
+ return 0;
+}
+
static std::map<std::string, std::function<int(int, char**)>> cmdmap = {
+ // clang-format off
{"create", DmCreateCmdHandler},
{"delete", DmDeleteCmdHandler},
{"list", DmListCmdHandler},
{"help", HelpCmdHandler},
+ {"getpath", GetPathCmdHandler},
+ // clang-format on
};
int main(int argc, char** argv) {
