vold2: Refactor FAT support into a separate class
Signed-off-by: San Mehat <san@google.com>
diff --git a/Fat.cpp b/Fat.cpp
new file mode 100644
index 0000000..ec1ead5
--- /dev/null
+++ b/Fat.cpp
@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+
+#include <linux/kdev_t.h>
+
+#define LOG_TAG "Vold"
+
+#include <cutils/log.h>
+#include <cutils/properties.h>
+
+#include "Fat.h"
+
+static char FSCK_MSDOS_PATH[] = "/system/bin/fsck_msdos";
+static char MKDOSFS_PATH[] = "/system/bin/newfs_msdos";
+extern "C" int logwrap(int argc, const char **argv, int background);
+extern "C" int mount(const char *, const char *, const char *, unsigned long, const void *);
+
+int Fat::check(const char *fsPath) {
+ bool rw = true;
+ if (access(FSCK_MSDOS_PATH, X_OK)) {
+ LOGW("Skipping fs checks\n");
+ return 0;
+ }
+
+ int pass = 1;
+ int rc = 0;
+ do {
+ const char *args[5];
+ args[0] = FSCK_MSDOS_PATH;
+ args[1] = "-p";
+ args[2] = "-f";
+ args[3] = fsPath;
+ args[4] = NULL;
+
+ rc = logwrap(4, args, 1);
+
+ switch(rc) {
+ case 0:
+ LOGI("Filesystem check completed OK");
+ return 0;
+
+ case 2:
+ LOGE("Filesystem check failed (not a FAT filesystem)");
+ errno = ENODATA;
+ return -1;
+
+ case 4:
+ if (pass++ <= 3) {
+ LOGW("Filesystem modified - rechecking (pass %d)",
+ pass);
+ continue;
+ }
+ LOGE("Failing check after too many rechecks");
+ errno = EIO;
+ return -1;
+
+ default:
+ LOGE("Filesystem check failed (unknown exit code %d)", rc);
+ errno = EIO;
+ return -1;
+ }
+ } while (0);
+
+ return 0;
+}
+
+int Fat::doMount(const char *fsPath, const char *mountPoint) {
+ int rc;
+ unsigned long flags;
+
+ flags = MS_NODEV | MS_NOEXEC | MS_NOSUID | MS_DIRSYNC;
+
+ /*
+ * Note: This is a temporary hack. If the sampling profiler is enabled,
+ * we make the SD card world-writable so any process can write snapshots.
+ *
+ * TODO: Remove this code once we have a drop box in system_server.
+ */
+ char value[PROPERTY_VALUE_MAX];
+ property_get("persist.sampling_profiler", value, "");
+ if (value[0] == '1') {
+ LOGW("The SD card is world-writable because the"
+ " 'persist.sampling_profiler' system property is set to '1'.");
+ rc = mount(fsPath, mountPoint, (const char *) "vfat", (unsigned long) flags,
+ (const void *) "utf8,uid=1000,gid=1015,fmask=000,dmask=000,shortname=mixed");
+ } else {
+ /*
+ * The mount masks restrict access so that:
+ * 1. The 'system' user cannot access the SD card at all -
+ * (protects system_server from grabbing file references)
+ * 2. Group users can RWX
+ * 3. Others can only RX
+ */
+ rc = mount(fsPath, mountPoint, "vfat", flags,
+ "utf8,uid=1000,gid=1015,fmask=702,dmask=702,shortname=mixed");
+ }
+
+ if (rc && errno == EROFS) {
+ LOGE("%s appears to be a read only filesystem - retrying mount RO", fsPath);
+ flags |= MS_RDONLY;
+ rc = mount(fsPath, mountPoint, "vfat", flags,
+ "utf8,uid=1000,gid=1015,fmask=702,dmask=702,shortname=mixed");
+ }
+
+ if (rc == 0) {
+ char *lost_path;
+ asprintf(&lost_path, "%s/LOST.DIR", mountPoint);
+ if (access(lost_path, F_OK)) {
+ /*
+ * Create a LOST.DIR in the root so we have somewhere to put
+ * lost cluster chains (fsck_msdos doesn't currently do this)
+ */
+ if (mkdir(lost_path, 0755)) {
+ LOGE("Unable to create LOST.DIR (%s)", strerror(errno));
+ }
+ }
+ free(lost_path);
+ }
+
+ return rc;
+}
+
+int Fat::format(const char *fsPath) {
+ unsigned int nr_sec;
+ int fd;
+
+ if ((fd = open(fsPath, O_RDWR)) < 0) {
+ LOGE("Error opening disk file (%s)", strerror(errno));
+ return -1;
+ }
+
+ if (ioctl(fd, BLKGETSIZE, &nr_sec)) {
+ LOGE("Unable to get device size (%s)", strerror(errno));
+ close(fd);
+ return -1;
+ }
+ close(fd);
+
+ const char *args[7];
+ int rc;
+ args[0] = MKDOSFS_PATH;
+ args[1] = "-F";
+ if ((nr_sec * 512) <= ((unsigned int) (1024*1024*1024) * 2))
+ args[2] = "16";
+ else
+ args[2] = "32";
+
+ args[3] = "-O";
+ args[4] = "android";
+ args[5] = fsPath;
+ args[6] = NULL;
+ rc = logwrap(7, args, 1);
+
+ if (rc == 0) {
+ LOGI("Filesystem formatted OK");
+ return 0;
+ } else {
+ LOGE("Format failed (unknown exit code %d)", rc);
+ errno = EIO;
+ return -1;
+ }
+ return 0;
+}