vold2: Get mounting/unmounting/formatting/sharing working

Signed-off-by: San Mehat <san@google.com>
diff --git a/Volume.cpp b/Volume.cpp
index bdd0ada..b9f030b 100644
--- a/Volume.cpp
+++ b/Volume.cpp
@@ -24,21 +24,62 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mman.h>
+#include <sys/mount.h>
+
+#include <linux/kdev_t.h>
+
+#include <cutils/properties.h>
+
+#include "diskmbr.h"
 
 #define LOG_TAG "Vold"
 
 #include <cutils/log.h>
 
 #include "Volume.h"
+#include "VolumeManager.h"
+#include "ResponseCode.h"
 
 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 *);
+extern "C" void KillProcessesWithOpenFiles(const char *, int, int, int);
+extern "C" void dos_partition_dec(void const *pp, struct dos_partition *d);
+extern "C" void dos_partition_enc(void *pp, struct dos_partition *d);
 
 static char FSCK_MSDOS_PATH[] = "/system/bin/fsck_msdos";
+static char MKDOSFS_PATH[] = "/system/bin/newfs_msdos";
 
-Volume::Volume(const char *label, const char *mount_point) {
+static const char *stateToStr(int state) {
+    if (state == Volume::State_Init)
+        return "Initializing";
+    else if (state == Volume::State_NoMedia)
+        return "No-Media";
+    else if (state == Volume::State_Idle)
+        return "Idle-Unmounted";
+    else if (state == Volume::State_Pending)
+        return "Pending";
+    else if (state == Volume::State_Mounted)
+        return "Mounted";
+    else if (state == Volume::State_Unmounting)
+        return "Unmounting";
+    else if (state == Volume::State_Checking)
+        return "Checking";
+    else if (state == Volume::State_Formatting)
+        return "Formatting";
+    else if (state == Volume::State_Shared)
+        return "Shared-Unmounted";
+    else if (state == Volume::State_SharedMnt)
+        return "Shared-Mounted";
+    else
+        return "Unknown-Error";
+}
+
+Volume::Volume(VolumeManager *vm, const char *label, const char *mount_point) {
+    mVm = vm;
     mLabel = strdup(label);
     mMountpoint = strdup(mount_point);
     mState = Volume::State_Init;
+    mCurrentlyMountedKdev = -1;
 }
 
 Volume::~Volume() {
@@ -46,14 +87,41 @@
     free(mMountpoint);
 }
 
+dev_t Volume::getDiskDevice() {
+    return MKDEV(0, 0);
+};
+
+void Volume::handleVolumeShared() {
+}
+
+void Volume::handleVolumeUnshared() {
+}
+
 int Volume::handleBlockEvent(NetlinkEvent *evt) {
     errno = ENOSYS;
     return -1;
 }
 
 void Volume::setState(int state) {
-    LOGD("Volume %s state changing %d -> %d", mLabel, mState, state);
+    char msg[255];
+    int oldState = mState;
+
+    if (oldState == state) {
+        LOGW("Duplicate state (%d)\n", state);
+        return;
+    }
+
     mState = state;
+
+    LOGD("Volume %s state changing %d (%s) -> %d (%s)", mLabel,
+         oldState, stateToStr(oldState), mState, stateToStr(mState));
+    snprintf(msg, sizeof(msg),
+             "Volume %s %s state changed from %d (%s) to %d (%s)", getLabel(),
+             getMountpoint(), oldState, stateToStr(oldState), mState,
+             stateToStr(mState));
+
+    mVm->getBroadcaster()->sendBroadcast(ResponseCode::VolumeStateChange,
+                                         msg, false);
 }
 
 int Volume::createDeviceNode(const char *path, int major, int minor) {
@@ -67,38 +135,227 @@
     return 0;
 }
 
-int Volume::mount() {
-    char nodepath[255];
-    int major = -1, minor = -1;
+int Volume::formatVol() {
 
-    if (prepareToMount(&major, &minor)) {
-        LOGE("Volume failed to prepare: %s", strerror(errno));
+    if (getState() == Volume::State_NoMedia) {
+        errno = ENODEV;
+        return -1;
+    } else if (getState() != Volume::State_Idle) {
+        errno = EBUSY;
         return -1;
     }
 
-    sprintf(nodepath, "/dev/block/vold/%d:%d", major, minor);
-
-    LOGD("nodepath = %s\n", nodepath);
-
-    /* Create device nodes */
-    if (createDeviceNode(nodepath, major, minor)) {
-        LOGE("Error making device nodes for '%s' (%s)", nodepath,
-             strerror(errno));
-        // XXX: cleanup will be needed eventually
+    if (isMountpointMounted(getMountpoint())) {
+        LOGW("Volume is idle but appears to be mounted - fixing");
+        setState(Volume::State_Mounted);
+        // mCurrentlyMountedKdev = XXX
+        errno = EBUSY;
         return -1;
     }
 
-    /* Run disk checker */
-    if (checkFilesystem(nodepath)) {
-        LOGE("Error checking filesystem (%s)", strerror(errno));
-        setState(Volume::State_Idle);
-        return -1;
+    char devicePath[255];
+    dev_t diskNode = getDiskDevice();
+    dev_t partNode = MKDEV(MAJOR(diskNode), 1); // XXX: Hmmm
+
+    sprintf(devicePath, "/dev/block/vold/%d:%d",
+            MAJOR(diskNode), MINOR(diskNode));
+
+    LOGI("Volume %s (%s) MBR being initialized", getLabel(), devicePath);
+
+    if (initializeMbr(devicePath)) {
+        LOGE("Failed to initialize MBR (%s)", strerror(errno));
+        goto err;
     }
 
-    
+    sprintf(devicePath, "/dev/block/vold/%d:%d",
+            MAJOR(partNode), MINOR(partNode));
 
-    setState(Volume::State_Idle);
+    LOGI("Volume %s (%s) being formatted", getLabel(), devicePath);
+
+    if (doFormatVfat(devicePath)) {
+        LOGE("Failed to format (%s)", strerror(errno));
+        goto err;
+    }
+
+    LOGI("Volume %s (%s) formatted sucessfully", getLabel(), devicePath);
     return 0;
+err:
+    return -1;
+}
+
+bool Volume::isMountpointMounted(const char *path) {
+    char device[256];
+    char mount_path[256];
+    char rest[256];
+    FILE *fp;
+    char line[1024];
+
+    if (!(fp = fopen("/proc/mounts", "r"))) {
+        LOGE("Error opening /proc/mounts (%s)", strerror(errno));
+        return false;
+    }
+
+    while(fgets(line, sizeof(line), fp)) {
+        line[strlen(line)-1] = '\0';
+        sscanf(line, "%255s %255s %255s\n", device, mount_path, rest);
+        if (!strcmp(mount_path, path)) {
+            fclose(fp);
+            return true;
+        }
+
+    }
+
+    fclose(fp);
+    return false;
+}
+
+int Volume::mountVol() {
+    dev_t deviceNodes[4];
+    int n, i, rc = 0;
+    char errmsg[255];
+
+    if (getState() == Volume::State_NoMedia) {
+        snprintf(errmsg, sizeof(errmsg),
+                 "Volume %s %s mount failed - no media",
+                 getLabel(), getMountpoint());
+        mVm->getBroadcaster()->sendBroadcast(
+                                         ResponseCode::VolumeMountFailedNoMedia,
+                                         errmsg, false);
+        errno = ENODEV;
+        return -1;
+    } else if (getState() != Volume::State_Idle) {
+        errno = EBUSY;
+        return -1;
+    }
+
+    if (isMountpointMounted(getMountpoint())) {
+        LOGW("Volume is idle but appears to be mounted - fixing");
+        setState(Volume::State_Mounted);
+        // mCurrentlyMountedKdev = XXX
+        return 0;
+    }
+
+    n = getDeviceNodes((dev_t *) &deviceNodes, 4);
+    if (!n) {
+        LOGE("Failed to get device nodes (%s)\n", strerror(errno));
+        return -1;
+    }
+
+    for (i = 0; i < n; i++) {
+        char devicePath[255];
+
+        sprintf(devicePath, "/dev/block/vold/%d:%d", MAJOR(deviceNodes[i]),
+                MINOR(deviceNodes[i]));
+
+        LOGI("%s being considered for volume %s\n", devicePath, getLabel());
+
+        errno = 0;
+        if ((rc = checkFilesystem(devicePath))) {
+            if (errno == ENODATA) {
+                LOGW("%s does not contain a FAT filesystem\n", devicePath);
+                continue;
+            } else {
+                /* Badness - abort the mount */
+                LOGE("%s failed FS checks (%s)", devicePath, strerror(errno));
+                snprintf(errmsg, sizeof(errmsg),
+                         "Volume %s %s mount failed - filesystem check failed",
+                         getLabel(), getMountpoint());
+                mVm->getBroadcaster()->sendBroadcast(
+                                         ResponseCode::VolumeMountFailedDamaged,
+                                         errmsg, false);
+                setState(Volume::State_Idle);
+                goto out;
+            }
+        }
+
+        LOGI("%s checks out - attempting to mount\n", devicePath);
+        errno = 0;
+        if (!(rc = doMountVfat(devicePath, getMountpoint()))) {
+            LOGI("%s sucessfully mounted for volume %s\n", devicePath,
+                 getLabel());
+            setState(Volume::State_Mounted);
+            mCurrentlyMountedKdev = deviceNodes[i];
+            goto out;
+        }
+
+        LOGW("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno));
+    }
+
+    // XXX: Doesn't handle multiple partitions properly
+    if (errno == ENODATA) {
+        snprintf(errmsg, sizeof(errmsg),
+                 "Volume %s %s mount failed - no supported file-systems",
+                 getLabel(), getMountpoint());
+        mVm->getBroadcaster()->sendBroadcast(
+                                 ResponseCode::VolumeMountFailedBlank,
+                                 errmsg, false);
+    }
+   
+
+    LOGE("Volume %s found no suitable devices for mounting :(\n", getLabel());
+    setState(Volume::State_Idle);
+
+out:
+    return rc;
+}
+
+
+int Volume::doMountVfat(const char *deviceNode, 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(deviceNode, 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(deviceNode, 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",
+             deviceNode);
+        flags |= MS_RDONLY;
+        rc = mount(deviceNode, 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 Volume::checkFilesystem(const char *nodepath) {
@@ -152,6 +409,133 @@
     return 0;
 }
 
-int Volume::unmount() {
+int Volume::unmountVol() {
+    int i, rc;
+
+    if (getState() != Volume::State_Mounted) {
+        LOGE("Volume %s unmount request when not mounted", getLabel());
+        errno = EINVAL;
+        return -1;
+    }
+
+    setState(Volume::State_Unmounting);
+    for (i = 0; i < 10; i++) {
+        rc = umount(getMountpoint());
+        if (!rc)
+            break;
+
+        if (rc && (errno == EINVAL || errno == ENOENT)) {
+            rc = 0;
+            break;
+        }
+
+        LOGW("Volume %s unmount attempt %d failed (%s)",
+             getLabel(), i + 1, strerror(errno));
+
+        if (i < 5) {
+            usleep(1000 * 250);
+        } else {
+            KillProcessesWithOpenFiles(getMountpoint(),
+                                       (i < 7 ? 0 : 1),
+                                       NULL, 0);
+            usleep(1000 * 250);
+        }
+    }
+
+    if (!rc) {
+        LOGI("Volume %s unmounted sucessfully", getLabel());
+        setState(Volume::State_Idle);
+        mCurrentlyMountedKdev = -1;
+        return 0;
+    }
+
+    LOGE("Volume %s failed to unmount (%s)\n", getLabel(), strerror(errno));
+    setState(Volume::State_Mounted);
+    return -1;
+}
+
+int Volume::initializeMbr(const char *deviceNode) {
+    int fd, rc;
+    unsigned char block[512];
+    struct dos_partition part;
+    unsigned int nr_sec;
+
+    if ((fd = open(deviceNode, 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;
+    }
+
+    memset(&part, 0, sizeof(part));
+    part.dp_flag = 0x80;
+    part.dp_typ = 0xc;
+    part.dp_start = ((1024 * 64) / 512) + 1;
+    part.dp_size = nr_sec - part.dp_start;
+
+    memset(block, 0, sizeof(block));
+    block[0x1fe] = 0x55;
+    block[0x1ff] = 0xaa;
+
+    dos_partition_enc(block + DOSPARTOFF, &part);
+
+    if (write(fd, block, sizeof(block)) < 0) {
+        LOGE("Error writing MBR (%s)", strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    if (ioctl(fd, BLKRRPART, NULL) < 0) {
+        LOGE("Error re-reading partition table (%s)", strerror(errno));
+        close(fd);
+        return -1;
+    }
+    close(fd);
+    return 0;
+}
+
+int Volume::doFormatVfat(const char *deviceNode) {
+    unsigned int nr_sec;
+    int fd;
+
+    if ((fd = open(deviceNode, 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] = deviceNode;
+    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;
 }