--- /dev/null
+/* Copyright (c) Mark Harmstone 2019
+ *
+ * This file is part of WinBtrfs.
+ *
+ * WinBtrfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public Licence as published by
+ * the Free Software Foundation, either version 3 of the Licence, or
+ * (at your option) any later version.
+ *
+ * WinBtrfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public Licence for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public Licence
+ * along with WinBtrfs. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "btrfs_drv.h"
+
+#ifndef __REACTOS__
+#ifdef _MSC_VER
+#include <ntstrsafe.h>
+#endif
+#else
+#include <ntstrsafe.h>
+#endif
+
+extern ERESOURCE pdo_list_lock;
+extern LIST_ENTRY pdo_list;
+
+#ifndef _MSC_VER
+NTSTATUS RtlUnicodeStringPrintf(PUNICODE_STRING DestinationString, const WCHAR* pszFormat, ...); // not in mingw
+#endif
+
+static bool get_system_root_partition(uint32_t* disk_num, uint32_t* partition_num) {
+ NTSTATUS Status;
+ HANDLE h;
+ UNICODE_STRING us, target;
+ OBJECT_ATTRIBUTES objatt;
+ WCHAR* s;
+ ULONG retlen = 0, left;
+
+ static const WCHAR system_root[] = L"\\SystemRoot";
+ static const WCHAR arc_prefix[] = L"\\ArcName\\multi(0)disk(0)rdisk(";
+ static const WCHAR arc_middle[] = L")partition(";
+
+ us.Buffer = (WCHAR*)system_root;
+ us.Length = us.MaximumLength = sizeof(system_root) - sizeof(WCHAR);
+
+ InitializeObjectAttributes(&objatt, &us, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL);
+
+ Status = ZwOpenSymbolicLinkObject(&h, GENERIC_READ, &objatt);
+ if (!NT_SUCCESS(Status)) {
+ ERR("ZwOpenSymbolicLinkObject returned %08x\n", Status);
+ return false;
+ }
+
+ target.Length = target.MaximumLength = 0;
+
+ Status = ZwQuerySymbolicLinkObject(h, &target, &retlen);
+ if (Status != STATUS_BUFFER_TOO_SMALL) {
+ ERR("ZwQuerySymbolicLinkObject returned %08x\n", Status);
+ NtClose(h);
+ return false;
+ }
+
+ if (retlen == 0) {
+ NtClose(h);
+ return false;
+ }
+
+ target.Buffer = ExAllocatePoolWithTag(NonPagedPool, retlen, ALLOC_TAG);
+ if (!target.Buffer) {
+ ERR("out of memory\n");
+ NtClose(h);
+ return false;
+ }
+
+ target.Length = target.MaximumLength = (USHORT)retlen;
+
+ Status = ZwQuerySymbolicLinkObject(h, &target, NULL);
+ if (!NT_SUCCESS(Status)) {
+ ERR("ZwQuerySymbolicLinkObject returned %08x\n", Status);
+ NtClose(h);
+ ExFreePool(target.Buffer);
+ return false;
+ }
+
+ NtClose(h);
+
+ TRACE("system root is %.*S\n", target.Length / sizeof(WCHAR), target.Buffer);
+
+ if (target.Length <= sizeof(arc_prefix) - sizeof(WCHAR) ||
+ RtlCompareMemory(target.Buffer, arc_prefix, sizeof(arc_prefix) - sizeof(WCHAR)) != sizeof(arc_prefix) - sizeof(WCHAR)) {
+ ExFreePool(target.Buffer);
+ return false;
+ }
+
+ s = &target.Buffer[(sizeof(arc_prefix) / sizeof(WCHAR)) - 1];
+ left = ((target.Length - sizeof(arc_prefix)) / sizeof(WCHAR)) + 1;
+
+ if (left == 0 || s[0] < '0' || s[0] > '9') {
+ ExFreePool(target.Buffer);
+ return false;
+ }
+
+ *disk_num = 0;
+
+ while (left > 0 && s[0] >= '0' && s[0] <= '9') {
+ *disk_num *= 10;
+ *disk_num += s[0] - '0';
+ s++;
+ left--;
+ }
+
+ if (left <= (sizeof(arc_middle) / sizeof(WCHAR)) - 1 ||
+ RtlCompareMemory(s, arc_middle, sizeof(arc_middle) - sizeof(WCHAR)) != sizeof(arc_middle) - sizeof(WCHAR)) {
+ ExFreePool(target.Buffer);
+ return false;
+ }
+
+ s = &s[(sizeof(arc_middle) / sizeof(WCHAR)) - 1];
+ left -= (sizeof(arc_middle) / sizeof(WCHAR)) - 1;
+
+ if (left == 0 || s[0] < '0' || s[0] > '9') {
+ ExFreePool(target.Buffer);
+ return false;
+ }
+
+ *partition_num = 0;
+
+ while (left > 0 && s[0] >= '0' && s[0] <= '9') {
+ *partition_num *= 10;
+ *partition_num += s[0] - '0';
+ s++;
+ left--;
+ }
+
+ ExFreePool(target.Buffer);
+
+ return true;
+}
+
+static void change_symlink(uint32_t disk_num, uint32_t partition_num, BTRFS_UUID* uuid) {
+ NTSTATUS Status;
+ UNICODE_STRING us, us2;
+ WCHAR symlink[60], target[(sizeof(BTRFS_VOLUME_PREFIX) / sizeof(WCHAR)) + 36], *w;
+#ifdef __REACTOS__
+ unsigned int i;
+#endif
+
+ us.Buffer = symlink;
+ us.Length = 0;
+ us.MaximumLength = sizeof(symlink);
+
+ Status = RtlUnicodeStringPrintf(&us, L"\\Device\\Harddisk%u\\Partition%u", disk_num, partition_num);
+ if (!NT_SUCCESS(Status)) {
+ ERR("RtlUnicodeStringPrintf returned %08x\n", Status);
+ return;
+ }
+
+ Status = IoDeleteSymbolicLink(&us);
+ if (!NT_SUCCESS(Status))
+ ERR("IoDeleteSymbolicLink returned %08x\n", Status);
+
+ RtlCopyMemory(target, BTRFS_VOLUME_PREFIX, sizeof(BTRFS_VOLUME_PREFIX) - sizeof(WCHAR));
+
+ w = &target[(sizeof(BTRFS_VOLUME_PREFIX) / sizeof(WCHAR)) - 1];
+
+#ifndef __REACTOS__
+ for (unsigned int i = 0; i < 16; i++) {
+#else
+ for (i = 0; i < 16; i++) {
+#endif
+ *w = hex_digit(uuid->uuid[i] >> 4); w++;
+ *w = hex_digit(uuid->uuid[i] & 0xf); w++;
+
+ if (i == 3 || i == 5 || i == 7 || i == 9) {
+ *w = L'-';
+ w++;
+ }
+ }
+
+ *w = L'}';
+
+ us2.Buffer = target;
+ us2.Length = us2.MaximumLength = sizeof(target);
+
+ Status = IoCreateSymbolicLink(&us, &us2);
+ if (!NT_SUCCESS(Status))
+ ERR("IoCreateSymbolicLink returned %08x\n", Status);
+}
+
+/* If booting from Btrfs, Windows will pass the device object for the raw partition to
+ * mount_vol - which is no good to us, as we only use the \Device\Btrfs{} devices we
+ * create so that RAID works correctly.
+ * At the time check_system_root gets called, \SystemRoot is a symlink to the ARC device,
+ * e.g. \ArcName\multi(0)disk(0)rdisk(0)partition(1)\Windows. We can't change the symlink,
+ * as it gets clobbered by IopReassignSystemRoot shortly afterwards, and we can't touch
+ * the \ArcName symlinks as they haven't been created yet. Instead, we need to change the
+ * symlink \Device\HarddiskX\PartitionY, which is what the ArcName symlink will shortly
+ * point to.
+ */
+void __stdcall check_system_root(PDRIVER_OBJECT DriverObject, PVOID Context, ULONG Count) {
+ uint32_t disk_num, partition_num;
+ LIST_ENTRY* le;
+ bool done = false;
+
+ TRACE("(%p, %p, %u)\n", DriverObject, Context, Count);
+
+ if (!get_system_root_partition(&disk_num, &partition_num))
+ return;
+
+ TRACE("system boot partition is disk %u, partition %u\n", disk_num, partition_num);
+
+ ExAcquireResourceSharedLite(&pdo_list_lock, true);
+
+ le = pdo_list.Flink;
+ while (le != &pdo_list) {
+ LIST_ENTRY* le2;
+ pdo_device_extension* pdode = CONTAINING_RECORD(le, pdo_device_extension, list_entry);
+
+ ExAcquireResourceSharedLite(&pdode->child_lock, true);
+
+ le2 = pdode->children.Flink;
+
+ while (le2 != &pdode->children) {
+ volume_child* vc = CONTAINING_RECORD(le2, volume_child, list_entry);
+
+ if (vc->disk_num == disk_num && vc->part_num == partition_num) {
+ change_symlink(disk_num, partition_num, &pdode->uuid);
+ done = true;
+ break;
+ }
+
+ le2 = le2->Flink;
+ }
+
+ ExReleaseResourceLite(&pdode->child_lock);
+
+ if (done)
+ break;
+
+ le = le->Flink;
+ }
+
+ ExReleaseResourceLite(&pdo_list_lock);
+}
projects / reactos.git / blobdiff