Merge changes from topic "zram_loop"
* changes:
Set the I/O scheduler of loop devices to 'none'
Rename two local variables
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 4e6d642..ec66144 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -34,11 +34,13 @@
#include <time.h>
#include <unistd.h>
+#include <array>
#include <chrono>
#include <functional>
#include <map>
#include <memory>
#include <string>
+#include <string_view>
#include <thread>
#include <utility>
#include <vector>
@@ -101,6 +103,7 @@
using android::base::Realpath;
using android::base::SetProperty;
using android::base::StartsWith;
+using android::base::StringPrintf;
using android::base::Timer;
using android::base::unique_fd;
using android::dm::DeviceMapper;
@@ -2044,6 +2047,35 @@
return 0;
}
+static bool ConfigureIoScheduler(const std::string& device_path) {
+ if (!StartsWith(device_path, "/dev/")) {
+ LERROR << __func__ << ": invalid argument " << device_path;
+ return false;
+ }
+
+ const std::string iosched_path =
+ StringPrintf("/sys/block/%s/queue/scheduler", Basename(device_path).c_str());
+ unique_fd iosched_fd(open(iosched_path.c_str(), O_RDWR | O_CLOEXEC));
+ if (iosched_fd.get() == -1) {
+ PERROR << __func__ << ": failed to open " << iosched_path;
+ return false;
+ }
+
+ // Kernels before v4.1 only support 'noop'. Kernels [v4.1, v5.0) support
+ // 'noop' and 'none'. Kernels v5.0 and later only support 'none'.
+ static constexpr const std::array<std::string_view, 2> kNoScheduler = {"none", "noop"};
+
+ for (const std::string_view& scheduler : kNoScheduler) {
+ int ret = write(iosched_fd.get(), scheduler.data(), scheduler.size());
+ if (ret > 0) {
+ return true;
+ }
+ }
+
+ PERROR << __func__ << ": failed to write to " << iosched_path;
+ return false;
+}
+
static bool InstallZramDevice(const std::string& device) {
if (!android::base::WriteStringToFile(device, ZRAM_BACK_DEV)) {
PERROR << "Cannot write " << device << " in: " << ZRAM_BACK_DEV;
@@ -2071,22 +2103,24 @@
// Allocate loop device and attach it to file_path.
LoopControl loop_control;
- std::string device;
- if (!loop_control.Attach(target_fd.get(), 5s, &device)) {
+ std::string loop_device;
+ if (!loop_control.Attach(target_fd.get(), 5s, &loop_device)) {
return false;
}
+ ConfigureIoScheduler(loop_device);
+
// set block size & direct IO
- unique_fd device_fd(TEMP_FAILURE_RETRY(open(device.c_str(), O_RDWR | O_CLOEXEC)));
- if (device_fd.get() == -1) {
- PERROR << "Cannot open " << device;
+ unique_fd loop_fd(TEMP_FAILURE_RETRY(open(loop_device.c_str(), O_RDWR | O_CLOEXEC)));
+ if (loop_fd.get() == -1) {
+ PERROR << "Cannot open " << loop_device;
return false;
}
- if (!LoopControl::EnableDirectIo(device_fd.get())) {
+ if (!LoopControl::EnableDirectIo(loop_fd.get())) {
return false;
}
- return InstallZramDevice(device);
+ return InstallZramDevice(loop_device);
}
bool fs_mgr_swapon_all(const Fstab& fstab) {