Loop.cpp - SHIFTPHONES/android_system_vold - Gitiles

 /*
  * 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.
  */

 #define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER

 #include <stdio.h>
 #include <stdlib.h>
 #include <dirent.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>

 #include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>

 #include <linux/kdev_t.h>

 #define LOG_TAG "Vold"

 #include <cutils/log.h>

 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/unique_fd.h>
 #include <utils/Trace.h>

 #include "Loop.h"
 #include "VoldUtil.h"
 #include "sehandle.h"

 using android::base::StringPrintf;
 using android::base::unique_fd;

 static const char* kVoldPrefix = "vold:";

 int Loop::lookupActive(const char *id_raw, char *buffer, size_t len) {
     auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
     const char* id = id_string.c_str();

     int i;
     int fd;
     char filename[256];

     memset(buffer, 0, len);

     for (i = 0; i < LOOP_MAX; i++) {
         struct loop_info64 li;
         int rc;

         snprintf(filename, sizeof(filename), "/dev/block/loop%d", i);

         if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
             if (errno != ENOENT) {
                 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
             } else {
                 continue;
             }
             return -1;
         }

         rc = ioctl(fd, LOOP_GET_STATUS64, &li);
         if (rc < 0 && errno == ENXIO) {
             close(fd);
             continue;
         }
         close(fd);

         if (rc < 0) {
             SLOGE("Unable to get loop status for %s (%s)", filename,
                  strerror(errno));
             return -1;
         }
         if (!strncmp((const char*) li.lo_crypt_name, id, LO_NAME_SIZE)) {
             break;
         }
     }

     if (i == LOOP_MAX) {
         errno = ENOENT;
         return -1;
     }
     strlcpy(buffer, filename, len);
     return 0;
 }

 int Loop::create(const char *id_raw, const char *loopFile, char *loopDeviceBuffer, size_t len) {
     auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
     const char* id = id_string.c_str();

     int i;
     int fd;
     char filename[256];

     for (i = 0; i < LOOP_MAX; i++) {
         struct loop_info64 li;
         int rc;
         char *secontext = NULL;

         snprintf(filename, sizeof(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 (sehandle) {
             rc = selabel_lookup(sehandle, &secontext, filename, S_IFBLK);
             if (rc == 0)
                 setfscreatecon(secontext);
         }

         if (mknod(filename, mode, dev) < 0) {
             if (errno != EEXIST) {
                 int sverrno = errno;
                 SLOGE("Error creating loop device node (%s)", strerror(errno));
                 if (secontext) {
                     freecon(secontext);
                     setfscreatecon(NULL);
                 }
                 errno = sverrno;
                 return -1;
             }
         }
         if (secontext) {
             freecon(secontext);
             setfscreatecon(NULL);
         }

         if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
             SLOGE("Unable to open %s (%s)", filename, strerror(errno));
             return -1;
         }

         rc = ioctl(fd, LOOP_GET_STATUS64, &li);
         if (rc < 0 && errno == ENXIO)
             break;

         close(fd);

         if (rc < 0) {
             SLOGE("Unable to get loop status for %s (%s)", filename,
                  strerror(errno));
             return -1;
         }
     }

     if (i == LOOP_MAX) {
         SLOGE("Exhausted all loop devices");
         errno = ENOSPC;
         return -1;
     }

     strlcpy(loopDeviceBuffer, filename, len);

     int file_fd;

     if ((file_fd = open(loopFile, O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Unable to open %s (%s)", loopFile, strerror(errno));
         close(fd);
         return -1;
     }

     if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) {
         SLOGE("Error setting up loopback interface (%s)", strerror(errno));
         close(file_fd);
         close(fd);
         return -1;
     }

     struct loop_info64 li;

     memset(&li, 0, sizeof(li));
     strlcpy((char*) li.lo_crypt_name, id, LO_NAME_SIZE);
     strlcpy((char*) li.lo_file_name, loopFile, LO_NAME_SIZE);

     if (ioctl(fd, LOOP_SET_STATUS64, &li) < 0) {
         SLOGE("Error setting loopback status (%s)", strerror(errno));
         close(file_fd);
         close(fd);
         return -1;
     }

     close(fd);
     close(file_fd);

     return 0;
 }

 int Loop::create(const std::string& target, std::string& out_device) {
     unique_fd ctl_fd(open("/dev/loop-control", O_RDWR | O_CLOEXEC));
     if (ctl_fd.get() == -1) {
         PLOG(ERROR) << "Failed to open loop-control";
         return -errno;
     }

     int num = ioctl(ctl_fd.get(), LOOP_CTL_GET_FREE);
     if (num == -1) {
         PLOG(ERROR) << "Failed LOOP_CTL_GET_FREE";
         return -errno;
     }

     out_device = StringPrintf("/dev/block/loop%d", num);

     unique_fd target_fd(open(target.c_str(), O_RDWR | O_CLOEXEC));
     if (target_fd.get() == -1) {
         PLOG(ERROR) << "Failed to open " << target;
         return -errno;
     }
     unique_fd device_fd(open(out_device.c_str(), O_RDWR | O_CLOEXEC));
     if (device_fd.get() == -1) {
         PLOG(ERROR) << "Failed to open " << out_device;
         return -errno;
     }

     if (ioctl(device_fd.get(), LOOP_SET_FD, target_fd.get()) == -1) {
         PLOG(ERROR) << "Failed to LOOP_SET_FD";
         return -errno;
     }

     struct loop_info64 li;
     memset(&li, 0, sizeof(li));
     strlcpy((char*) li.lo_crypt_name, kVoldPrefix, LO_NAME_SIZE);
     if (ioctl(device_fd.get(), LOOP_SET_STATUS64, &li) == -1) {
         PLOG(ERROR) << "Failed to LOOP_SET_STATUS64";
         return -errno;
     }

     return 0;
 }

 int Loop::destroyByDevice(const char *loopDevice) {
     int device_fd;

     device_fd = open(loopDevice, O_RDONLY | O_CLOEXEC);
     if (device_fd < 0) {
         SLOGE("Failed to open loop (%d)", errno);
         return -1;
     }

     if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
         SLOGE("Failed to destroy loop (%d)", errno);
         close(device_fd);
         return -1;
     }

     close(device_fd);
     return 0;
 }

 int Loop::destroyAll() {
     ATRACE_NAME("Loop::destroyAll");

     DIR* dir;
     struct dirent* de;

     std::string root = "/dev/block/";
     if (!(dir = opendir(root.c_str()))) {
         PLOG(ERROR) << "Failed to opendir";
         return -1;
     }

     // Poke through all devices looking for loops
     while ((de = readdir(dir))) {
         if (strncmp(de->d_name, "loop", 4) != 0) continue;

         auto path = root + de->d_name;
         unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));
         if (fd.get() == -1) {
             if (errno != ENOENT) {
                 PLOG(WARNING) << "Failed to open " << path;
             }
             continue;
         }

         struct loop_info64 li;
         if (ioctl(fd.get(), LOOP_GET_STATUS64, &li) < 0) {
             PLOG(WARNING) << "Failed to LOOP_GET_STATUS64 " << path;
             continue;
         }

         char* id = (char*) li.lo_crypt_name;
         if (strncmp(id, kVoldPrefix, strlen(kVoldPrefix)) == 0) {
             LOG(DEBUG) << "Tearing down stale loop device at " << path << " named " << id;

             if (ioctl(fd.get(), LOOP_CLR_FD, 0) < 0) {
                 PLOG(WARNING) << "Failed to LOOP_CLR_FD " << path;
             }
         } else {
             LOG(VERBOSE) << "Found unmanaged loop device at " << path << " named " << id;
         }
     }

     closedir(dir);
     return 0;
 }

 int Loop::createImageFile(const char *file, unsigned long numSectors) {
     unique_fd fd(open(file, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0600));
     if (fd.get() == -1) {
         PLOG(ERROR) << "Failed to create image " << file;
         return -errno;
     }
     if (fallocate(fd.get(), 0, 0, numSectors * 512) == -1) {
         PLOG(WARNING) << "Failed to fallocate; falling back to ftruncate";
         if (ftruncate(fd, numSectors * 512) == -1) {
             PLOG(ERROR) << "Failed to ftruncate";
             return -errno;
         }
     }
     return 0;
 }

 int Loop::resizeImageFile(const char *file, unsigned long numSectors) {
     int fd;

     if ((fd = open(file, O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Error opening imagefile (%s)", strerror(errno));
         return -1;
     }

     SLOGD("Attempting to increase size of %s to %lu sectors.", file, numSectors);

     if (fallocate(fd, 0, 0, numSectors * 512)) {
         if (errno == ENOSYS || errno == ENOTSUP) {
             SLOGW("fallocate not found. Falling back to ftruncate.");
             if (ftruncate(fd, numSectors * 512) < 0) {
                 SLOGE("Error truncating imagefile (%s)", strerror(errno));
                 close(fd);
                 return -1;
             }
         } else {
             SLOGE("Error allocating space (%s)", strerror(errno));
             close(fd);
             return -1;
         }
     }
     close(fd);
     return 0;
 }
	/*
	* 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.
	*/

	#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER

	#include <stdio.h>
	#include <stdlib.h>
	#include <dirent.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <errno.h>
	#include <string.h>

	#include <sys/mount.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>

	#include <linux/kdev_t.h>

	#define LOG_TAG "Vold"

	#include <cutils/log.h>

	#include <android-base/logging.h>
	#include <android-base/stringprintf.h>
	#include <android-base/unique_fd.h>
	#include <utils/Trace.h>

	#include "Loop.h"
	#include "VoldUtil.h"
	#include "sehandle.h"

	using android::base::StringPrintf;
	using android::base::unique_fd;

	static const char* kVoldPrefix = "vold:";

	int Loop::lookupActive(const char id_raw, char buffer, size_t len) {
	auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
	const char* id = id_string.c_str();

	int i;
	int fd;
	char filename[256];

	memset(buffer, 0, len);

	for (i = 0; i < LOOP_MAX; i++) {
	struct loop_info64 li;
	int rc;

	snprintf(filename, sizeof(filename), "/dev/block/loop%d", i);

	if ((fd = open(filename, O_RDWR \| O_CLOEXEC)) < 0) {
	if (errno != ENOENT) {
	SLOGE("Unable to open %s (%s)", filename, strerror(errno));
	} else {
	continue;
	}
	return -1;
	}

	rc = ioctl(fd, LOOP_GET_STATUS64, &li);
	if (rc < 0 && errno == ENXIO) {
	close(fd);
	continue;
	}
	close(fd);

	if (rc < 0) {
	SLOGE("Unable to get loop status for %s (%s)", filename,
	strerror(errno));
	return -1;
	}
	if (!strncmp((const char*) li.lo_crypt_name, id, LO_NAME_SIZE)) {
	break;
	}
	}

	if (i == LOOP_MAX) {
	errno = ENOENT;
	return -1;
	}
	strlcpy(buffer, filename, len);
	return 0;
	}

	int Loop::create(const char id_raw, const char loopFile, char *loopDeviceBuffer, size_t len) {
	auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
	const char* id = id_string.c_str();

	int i;
	int fd;
	char filename[256];

	for (i = 0; i < LOOP_MAX; i++) {
	struct loop_info64 li;
	int rc;
	char *secontext = NULL;

	snprintf(filename, sizeof(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 (sehandle) {
	rc = selabel_lookup(sehandle, &secontext, filename, S_IFBLK);
	if (rc == 0)
	setfscreatecon(secontext);
	}

	if (mknod(filename, mode, dev) < 0) {
	if (errno != EEXIST) {
	int sverrno = errno;
	SLOGE("Error creating loop device node (%s)", strerror(errno));
	if (secontext) {
	freecon(secontext);
	setfscreatecon(NULL);
	}
	errno = sverrno;
	return -1;
	}
	}
	if (secontext) {
	freecon(secontext);
	setfscreatecon(NULL);
	}

	if ((fd = open(filename, O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Unable to open %s (%s)", filename, strerror(errno));
	return -1;
	}

	rc = ioctl(fd, LOOP_GET_STATUS64, &li);
	if (rc < 0 && errno == ENXIO)
	break;

	close(fd);

	if (rc < 0) {
	SLOGE("Unable to get loop status for %s (%s)", filename,
	strerror(errno));
	return -1;
	}
	}

	if (i == LOOP_MAX) {
	SLOGE("Exhausted all loop devices");
	errno = ENOSPC;
	return -1;
	}

	strlcpy(loopDeviceBuffer, filename, len);

	int file_fd;

	if ((file_fd = open(loopFile, O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Unable to open %s (%s)", loopFile, strerror(errno));
	close(fd);
	return -1;
	}

	if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) {
	SLOGE("Error setting up loopback interface (%s)", strerror(errno));
	close(file_fd);
	close(fd);
	return -1;
	}

	struct loop_info64 li;

	memset(&li, 0, sizeof(li));
	strlcpy((char*) li.lo_crypt_name, id, LO_NAME_SIZE);
	strlcpy((char*) li.lo_file_name, loopFile, LO_NAME_SIZE);

	if (ioctl(fd, LOOP_SET_STATUS64, &li) < 0) {
	SLOGE("Error setting loopback status (%s)", strerror(errno));
	close(file_fd);
	close(fd);
	return -1;
	}

	close(fd);
	close(file_fd);

	return 0;
	}

	int Loop::create(const std::string& target, std::string& out_device) {
	unique_fd ctl_fd(open("/dev/loop-control", O_RDWR \| O_CLOEXEC));
	if (ctl_fd.get() == -1) {
	PLOG(ERROR) << "Failed to open loop-control";
	return -errno;
	}

	int num = ioctl(ctl_fd.get(), LOOP_CTL_GET_FREE);
	if (num == -1) {
	PLOG(ERROR) << "Failed LOOP_CTL_GET_FREE";
	return -errno;
	}

	out_device = StringPrintf("/dev/block/loop%d", num);

	unique_fd target_fd(open(target.c_str(), O_RDWR \| O_CLOEXEC));
	if (target_fd.get() == -1) {
	PLOG(ERROR) << "Failed to open " << target;
	return -errno;
	}
	unique_fd device_fd(open(out_device.c_str(), O_RDWR \| O_CLOEXEC));
	if (device_fd.get() == -1) {
	PLOG(ERROR) << "Failed to open " << out_device;
	return -errno;
	}

	if (ioctl(device_fd.get(), LOOP_SET_FD, target_fd.get()) == -1) {
	PLOG(ERROR) << "Failed to LOOP_SET_FD";
	return -errno;
	}

	struct loop_info64 li;
	memset(&li, 0, sizeof(li));
	strlcpy((char*) li.lo_crypt_name, kVoldPrefix, LO_NAME_SIZE);
	if (ioctl(device_fd.get(), LOOP_SET_STATUS64, &li) == -1) {
	PLOG(ERROR) << "Failed to LOOP_SET_STATUS64";
	return -errno;
	}

	return 0;
	}

	int Loop::destroyByDevice(const char *loopDevice) {
	int device_fd;

	device_fd = open(loopDevice, O_RDONLY \| O_CLOEXEC);
	if (device_fd < 0) {
	SLOGE("Failed to open loop (%d)", errno);
	return -1;
	}

	if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
	SLOGE("Failed to destroy loop (%d)", errno);
	close(device_fd);
	return -1;
	}

	close(device_fd);
	return 0;
	}

	int Loop::destroyAll() {
	ATRACE_NAME("Loop::destroyAll");

	DIR* dir;
	struct dirent* de;

	std::string root = "/dev/block/";
	if (!(dir = opendir(root.c_str()))) {
	PLOG(ERROR) << "Failed to opendir";
	return -1;
	}

	// Poke through all devices looking for loops
	while ((de = readdir(dir))) {
	if (strncmp(de->d_name, "loop", 4) != 0) continue;

	auto path = root + de->d_name;
	unique_fd fd(open(path.c_str(), O_RDWR \| O_CLOEXEC));
	if (fd.get() == -1) {
	if (errno != ENOENT) {
	PLOG(WARNING) << "Failed to open " << path;
	}
	continue;
	}

	struct loop_info64 li;
	if (ioctl(fd.get(), LOOP_GET_STATUS64, &li) < 0) {
	PLOG(WARNING) << "Failed to LOOP_GET_STATUS64 " << path;
	continue;
	}

	char* id = (char*) li.lo_crypt_name;
	if (strncmp(id, kVoldPrefix, strlen(kVoldPrefix)) == 0) {
	LOG(DEBUG) << "Tearing down stale loop device at " << path << " named " << id;

	if (ioctl(fd.get(), LOOP_CLR_FD, 0) < 0) {
	PLOG(WARNING) << "Failed to LOOP_CLR_FD " << path;
	}
	} else {
	LOG(VERBOSE) << "Found unmanaged loop device at " << path << " named " << id;
	}
	}

	closedir(dir);
	return 0;
	}

	int Loop::createImageFile(const char *file, unsigned long numSectors) {
	unique_fd fd(open(file, O_CREAT \| O_WRONLY \| O_TRUNC \| O_CLOEXEC, 0600));
	if (fd.get() == -1) {
	PLOG(ERROR) << "Failed to create image " << file;
	return -errno;
	}
	if (fallocate(fd.get(), 0, 0, numSectors * 512) == -1) {
	PLOG(WARNING) << "Failed to fallocate; falling back to ftruncate";
	if (ftruncate(fd, numSectors * 512) == -1) {
	PLOG(ERROR) << "Failed to ftruncate";
	return -errno;
	}
	}
	return 0;
	}

	int Loop::resizeImageFile(const char *file, unsigned long numSectors) {
	int fd;

	if ((fd = open(file, O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Error opening imagefile (%s)", strerror(errno));
	return -1;
	}

	SLOGD("Attempting to increase size of %s to %lu sectors.", file, numSectors);

	if (fallocate(fd, 0, 0, numSectors * 512)) {
	if (errno == ENOSYS \|\| errno == ENOTSUP) {
	SLOGW("fallocate not found. Falling back to ftruncate.");
	if (ftruncate(fd, numSectors * 512) < 0) {
	SLOGE("Error truncating imagefile (%s)", strerror(errno));
	close(fd);
	return -1;
	}
	} else {
	SLOGE("Error allocating space (%s)", strerror(errno));
	close(fd);
	return -1;
	}
	}
	close(fd);
	return 0;
	}