/* * 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 #include #include #include #include #include #include #define LOG_TAG "Vold" #include #include "Loop.h" int Loop::lookupActive(const char *loopFile, char *buffer, size_t len) { int i; int fd; char filename[256]; memset(buffer, 0, len); for (i = 0; i < LOOP_MAX; i++) { struct loop_info li; int rc; sprintf(filename, "/dev/block/loop%d", i); if ((fd = open(filename, O_RDWR)) < 0) { if (errno != ENOENT) { LOGE("Unable to open %s (%s)", filename, strerror(errno)); } return -1; } rc = ioctl(fd, LOOP_GET_STATUS, &li); close(fd); if (rc < 0 && errno == ENXIO) { continue; break; } if (rc < 0) { LOGE("Unable to get loop status for %s (%s)", filename, strerror(errno)); return -1; } if (!strncmp(li.lo_name, loopFile, LO_NAME_SIZE)) { break; } } if (i == LOOP_MAX) { errno = ENOENT; return -1; } strncpy(buffer, filename, len -1); return 0; } int Loop::create(const char *loopFile, char *loopDeviceBuffer, size_t len) { int i; int fd; char filename[256]; for (i = 0; i < LOOP_MAX; i++) { struct loop_info li; int rc; sprintf(filename, "/dev/block/loop%d", i); /* * The kernel starts us off with 8 loop nodes, but more * are created on-demand if needed. */ mode_t mode = 0660 | S_IFBLK; unsigned int dev = (0xff & i) | ((i << 12) & 0xfff00000) | (7 << 8); if (mknod(filename, mode, dev) < 0) { if (errno != EEXIST) { LOGE("Error creating loop device node (%s)", strerror(errno)); return -1; } } if ((fd = open(filename, O_RDWR)) < 0) { LOGE("Unable to open %s (%s)", filename, strerror(errno)); return -1; } rc = ioctl(fd, LOOP_GET_STATUS, &li); if (rc < 0 && errno == ENXIO) break; close(fd); if (rc < 0) { LOGE("Unable to get loop status for %s (%s)", filename, strerror(errno)); return -1; } } if (i == LOOP_MAX) { LOGE("Exhausted all loop devices"); errno = ENOSPC; return -1; } strncpy(loopDeviceBuffer, filename, len -1); int file_fd; if ((file_fd = open(loopFile, O_RDWR)) < 0) { LOGE("Unable to open %s (%s)", loopFile, strerror(errno)); close(fd); return -1; } if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) { LOGE("Error setting up loopback interface (%s)", strerror(errno)); close(file_fd); close(fd); return -1; } struct loop_info li; memset(&li, 0, sizeof(li)); strncpy(li.lo_name, loopFile, LO_NAME_SIZE); if (ioctl(fd, LOOP_SET_STATUS, &li) < 0) { LOGE("Error setting loopback status (%s)", strerror(errno)); close(file_fd); close(fd); return -1; } close(fd); close(file_fd); return 0; } int Loop::destroyByDevice(const char *loopDevice) { int device_fd; device_fd = open(loopDevice, O_RDONLY); if (device_fd < 0) { LOGE("Failed to open loop (%d)", errno); return -1; } if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) { LOGE("Failed to destroy loop (%d)", errno); close(device_fd); return -1; } close(device_fd); return 0; } int Loop::destroyByFile(const char *loopFile) { errno = ENOSYS; return -1; } int Loop::createImageFile(const char *file, unsigned int numSectors) { int fd; LOGD("Creating image file %s (%u sectors)", file, numSectors); if ((fd = creat(file, 0600)) < 0) { LOGE("Error creating imagefile (%s)", strerror(errno)); return -1; } if (ftruncate(fd, numSectors * 512) < 0) { LOGE("Error truncating imagefile (%s)", strerror(errno)); close(fd); return -1; } close(fd); return 0; }