Merge changes from topic "sys_rootdisk" am: 4c7dc7bd1d am: 09dc4e679d am: 397e014a13
Original change: https://android-review.googlesource.com/c/platform/system/core/+/2008276
Change-Id: I73724e4b42bb56e3e9359a5dc7da6e474eb777a4
diff --git a/init/README.md b/init/README.md
index c82dbfb..13c6ebd 100644
--- a/init/README.md
+++ b/init/README.md
@@ -804,13 +804,18 @@
`init.svc.<name>`
> State of a named service ("stopped", "stopping", "running", "restarting")
-`dev.mnt.blk.<mount_point>`
+`dev.mnt.dev.<mount_point>`, `dev.mnt.blk.<mount_point>`, `dev.mnt.rootdisk.<mount_point>`
> Block device base name associated with a *mount_point*.
The *mount_point* has / replaced by . and if referencing the root mount point
- "/", it will use "/root", specifically `dev.mnt.blk.root`.
- Meant for references to `/sys/device/block/${dev.mnt.blk.<mount_point>}/` and
- `/sys/fs/ext4/${dev.mnt.blk.<mount_point>}/` to tune the block device
- characteristics in a device agnostic manner.
+ "/", it will use "/root".
+ `dev.mnt.dev.<mount_point>` indicates a block device attached to filesystems.
+ (e.g., dm-N or sdaN/mmcblk0pN to access `/sys/fs/ext4/${dev.mnt.dev.<mount_point>}/`)
+
+ `dev.mnt.blk.<mount_point>` indicates the disk partition to the above block device.
+ (e.g., sdaN / mmcblk0pN to access `/sys/class/block/${dev.mnt.blk.<mount_point>}/`)
+
+ `dev.mnt.rootdisk.<mount_point>` indicates the root disk to contain the above disk partition.
+ (e.g., sda / mmcblk0 to access `/sys/class/block/${dev.mnt.rootdisk.<mount_point>}/queue`)
Init responds to properties that begin with `ctl.`. These properties take the format of
`ctl.[<target>_]<command>` and the _value_ of the system property is used as a parameter. The
diff --git a/init/mount_handler.cpp b/init/mount_handler.cpp
index f0d8d45..227ce2f 100644
--- a/init/mount_handler.cpp
+++ b/init/mount_handler.cpp
@@ -25,6 +25,7 @@
#include <unistd.h>
#include <algorithm>
+#include <filesystem>
#include <string>
#include <utility>
#include <vector>
@@ -32,6 +33,7 @@
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <fs_mgr.h>
#include <fstab/fstab.h>
@@ -39,6 +41,9 @@
#include "epoll.h"
+using android::base::Basename;
+using android::base::StringPrintf;
+
namespace android {
namespace init {
@@ -67,41 +72,82 @@
return MountHandlerEntry(fields[0], fields[1], fields[2]);
}
+// return sda25 for dm-4, sda25 for sda25, or mmcblk0p24 for mmcblk0p24
+std::string GetDiskPart(std::string blockdev) {
+ if (blockdev.find('/') != std::string::npos) return {};
+
+ while (android::base::StartsWith(blockdev, "dm-")) {
+ auto& dm = dm::DeviceMapper::Instance();
+ std::optional<std::string> parent = dm.GetParentBlockDeviceByPath("/dev/block/" + blockdev);
+ if (parent) {
+ blockdev = android::base::Basename(*parent);
+ } else {
+ return {};
+ }
+ }
+ return blockdev;
+}
+
+// return sda for sda25, or mmcblk0 for mmcblk0p24
+std::string GetRootDisk(std::string blockdev) {
+ if (blockdev.empty()) return {};
+ if (blockdev.find('/') != std::string::npos) return {};
+
+ std::error_code ec;
+ for (const auto& entry : std::filesystem::directory_iterator("/sys/block", ec)) {
+ const std::string path = entry.path().string();
+ if (std::filesystem::exists(StringPrintf("%s/%s", path.c_str(), blockdev.c_str()))) {
+ return Basename(path);
+ }
+ }
+ return {};
+}
+
void SetMountProperty(const MountHandlerEntry& entry, bool add) {
static constexpr char devblock[] = "/dev/block/";
if (!android::base::StartsWith(entry.blk_device, devblock)) return;
- std::string value;
+ auto target = entry.blk_device.substr(strlen(devblock));
+ std::string diskpart, rootdisk;
if (add) {
- value = entry.blk_device.substr(strlen(devblock));
- if (android::base::StartsWith(value, "sd")) {
- // All sd partitions inherit their queue characteristics
- // from the whole device reference. Strip partition number.
- auto it = std::find_if(value.begin(), value.end(), [](char c) { return isdigit(c); });
- if (it != value.end()) value.erase(it, value.end());
- }
- auto queue = "/sys/block/" + value + "/queue";
+ diskpart = GetDiskPart(target);
+ rootdisk = GetRootDisk(diskpart);
+
struct stat sb;
- if (stat(queue.c_str(), &sb) || !S_ISDIR(sb.st_mode)) value = "";
- if (stat(entry.mount_point.c_str(), &sb) || !S_ISDIR(sb.st_mode)) value = "";
+ if (stat(entry.mount_point.c_str(), &sb) || !S_ISDIR(sb.st_mode)) rootdisk = "";
// Clear the noise associated with loopback and APEX.
- if (android::base::StartsWith(value, "loop")) value = "";
- if (android::base::StartsWith(entry.mount_point, "/apex/")) value = "";
+ if (android::base::StartsWith(target, "loop")) rootdisk = "";
+ if (android::base::StartsWith(entry.mount_point, "/apex/")) rootdisk = "";
}
auto mount_prop = entry.mount_point;
if (mount_prop == "/") mount_prop = "/root";
std::replace(mount_prop.begin(), mount_prop.end(), '/', '.');
auto blk_mount_prop = "dev.mnt.blk" + mount_prop;
auto dev_mount_prop = "dev.mnt.dev" + mount_prop;
- // Set property even if its value does not change to trigger 'on property:'
+ auto rootdisk_mount_prop = "dev.mnt.rootdisk" + mount_prop;
+ // Set property even if its rootdisk does not change to trigger 'on property:'
// handling, except for clearing non-existent or already clear property.
// Goal is reduction of empty properties and associated triggers.
- if (value.empty() && android::base::GetProperty(blk_mount_prop, "").empty()) return;
- android::base::SetProperty(blk_mount_prop, value);
- if (!value.empty()) {
- android::base::SetProperty(dev_mount_prop, entry.blk_device.substr(strlen(devblock)));
- } else {
+ if (rootdisk.empty() && android::base::GetProperty(blk_mount_prop, "").empty()) return;
+
+ if (rootdisk.empty()) {
+ android::base::SetProperty(blk_mount_prop, "");
android::base::SetProperty(dev_mount_prop, "");
+ android::base::SetProperty(rootdisk_mount_prop, "");
+ return;
}
+
+ // 1. dm-N
+ // dev.mnt.dev.data = dm-N
+ // dev.mnt.blk.data = sdaN or mmcblk0pN
+ // dev.mnt.rootdisk.data = sda or mmcblk0
+ //
+ // 2. sdaN or mmcblk0pN
+ // dev.mnt.dev.data = sdaN or mmcblk0pN
+ // dev.mnt.blk.data = sdaN or mmcblk0pN
+ // dev.mnt.rootdisk.data = sda or mmcblk0
+ android::base::SetProperty(dev_mount_prop, target);
+ android::base::SetProperty(blk_mount_prop, diskpart);
+ android::base::SetProperty(rootdisk_mount_prop, rootdisk);
}
} // namespace
diff --git a/rootdir/init.rc b/rootdir/init.rc
index c4c9eca..404d7ae 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -1085,9 +1085,11 @@
mkdir /dev/sys/fs/by-name 0755 system system
symlink /sys/fs/f2fs/${dev.mnt.dev.data} /dev/sys/fs/by-name/userdata
- # to access dm-<num> sysfs
+ # dev.mnt.dev.data=dm-N, dev.mnt.blk.data=sdaN/mmcblk0pN, dev.mnt.rootdisk.data=sda/mmcblk0, or
+ # dev.mnt.dev.data=sdaN/mmcblk0pN, dev.mnt.blk.data=sdaN/mmcblk0pN, dev.mnt.rootdisk.data=sda/mmcblk0
mkdir /dev/sys/block/by-name 0755 system system
- symlink /sys/devices/virtual/block/${dev.mnt.dev.data} /dev/sys/block/by-name/userdata
+ symlink /sys/class/block/${dev.mnt.dev.data} /dev/sys/block/by-name/userdata
+ symlink /sys/class/block/${dev.mnt.rootdisk.data} /dev/sys/block/by-name/rootdisk
# F2FS tuning. Set cp_interval larger than dirty_expire_centisecs, 30 secs,
# to avoid power consumption when system becomes mostly idle. Be careful
@@ -1099,8 +1101,9 @@
# limit discard size to 128MB in order to avoid long IO latency
# for filesystem tuning first (dm or sda)
- # Note that, if dm-<num> is used, sda/mmcblk0 should be tuned in vendor/init.rc
+ # this requires enabling selinux entry for sda/mmcblk0 in vendor side
write /dev/sys/block/by-name/userdata/queue/discard_max_bytes 134217728
+ write /dev/sys/block/by-name/rootdisk/queue/discard_max_bytes 134217728
# Permissions for System Server and daemons.
chown system system /sys/power/autosleep