C++ (Cpp) openLun Examples

Example #1

File: VolumeManager.cpp Project: 0xD34D/system_vold

int VolumeManager::unshareVolume(const char *label, const char *method) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    if (strcmp(method, "ums")) {
        errno = ENOSYS;
        return -1;
    }

    if (v->getState() != Volume::State_Shared) {
        errno = EINVAL;
        return -1;
    }

    int fd;
    int lun_number;

    // /mnt/sdcard to lun0 and anything else to lun1. Fix this.
    if (v->isPrimaryStorage()) {
        lun_number = 0;
    } else {
        lun_number = SECOND_LUN_NUM;
    }

    if ((fd = openLun(lun_number)) < 0) {
        return -1;
    }

    char ch = 0;
    if (write(fd, &ch, 1) < 0) {
        SLOGE("Unable to write to ums lunfile (%s)", strerror(errno));
        close(fd);
        return -1;
    }

    close(fd);
    v->handleVolumeUnshared();
    if (--mUmsSharingCount == 0 && mSavedDirtyRatio != -1) {
        FILE* fp;
        if ((fp = fopen("/proc/sys/vm/dirty_ratio", "r+"))) {
            fprintf(fp, "%d\n", mSavedDirtyRatio);
            fclose(fp);
        } else {
            SLOGE("Failed to open /proc/sys/vm/dirty_ratio (%s)", strerror(errno));
        }
        mSavedDirtyRatio = -1;
    }
    return 0;
}

Example #2

File: VolumeManager.cpp Project: optimumpr/android_system_vold

int VolumeManager::shareVolume(const char *label, const char *method) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    /*
     * Eventually, we'll want to support additional share back-ends,
     * some of which may work while the media is mounted. For now,
     * we just support UMS
     */
    if (strcmp(method, "ums")) {
        errno = ENOSYS;
        return -1;
    }

    if (v->getState() == Volume::State_NoMedia) {
        errno = ENODEV;
        return -1;
    }

    if (v->getState() != Volume::State_Idle) {
        // You need to unmount manually befoe sharing
        errno = EBUSY;
        return -1;
    }

    if (mVolManagerDisabled) {
        errno = EBUSY;
        return -1;
    }

    dev_t d = v->getShareDevice();
    if ((MAJOR(d) == 0) && (MINOR(d) == 0)) {
        // This volume does not support raw disk access
        errno = EINVAL;
        return -1;
    }

#ifdef VOLD_EMMC_SHARES_DEV_MAJOR
    // If emmc and sdcard share dev major number, vold may pick
    // incorrectly based on partition nodes alone. Use device nodes instead.
    v->getDeviceNodes((dev_t *) &d, 1);
    if ((MAJOR(d) == 0) && (MINOR(d) == 0)) {
        // This volume does not support raw disk access
        errno = EINVAL;
        return -1;
    }
#endif

    int fd;
    char nodepath[255];
    int written = snprintf(nodepath,
             sizeof(nodepath), "/dev/block/vold/%d:%d",
             MAJOR(d), MINOR(d));

    if ((written < 0) || (size_t(written) >= sizeof(nodepath))) {
        SLOGE("shareVolume failed: couldn't construct nodepath");
        return -1;
    }

    if ((fd = openLun(v->getLunNumber())) < 0) {
        return -1;
    }

    if (write(fd, nodepath, strlen(nodepath)) < 0) {
        SLOGE("Unable to write to ums lunfile (%s)", strerror(errno));
        close(fd);
        return -1;
    }

    close(fd);
    v->handleVolumeShared();
    if (mUmsSharingCount++ == 0) {
        FILE* fp;
        mSavedDirtyRatio = -1; // in case we fail
        if ((fp = fopen("/proc/sys/vm/dirty_ratio", "r+"))) {
            char line[16];
            if (fgets(line, sizeof(line), fp) && sscanf(line, "%d", &mSavedDirtyRatio)) {
                fprintf(fp, "%d\n", mUmsDirtyRatio);
            } else {
                SLOGE("Failed to read dirty_ratio (%s)", strerror(errno));
            }
            fclose(fp);
        } else {
            SLOGE("Failed to open /proc/sys/vm/dirty_ratio (%s)", strerror(errno));
        }
    }
    return 0;
}