X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=lib%2Futils_device.c;h=75449c09a3bc94271fc29be006d564ed2eeb96b7;hb=322b430a2589cdc7985e98a14ec12322b91c9d5e;hp=d3e848abf858bdf3ed3fd6afff09aa95cb5c38fa;hpb=a83cc1dbf42a95a48cb087e22f8ae28633c40a65;p=platform%2Fupstream%2Fcryptsetup.git

diff --git a/lib/utils_device.c b/lib/utils_device.c
index d3e848a..75449c0 100644
--- a/lib/utils_device.c
+++ b/lib/utils_device.c
@@ -1,13 +1,15 @@
 /*
  * device backend utilities
  *
- * Copyright (C) 2004, Christophe Saout <christophe@saout.de>
- * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
- * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004 Jana Saout <jana@saout.de>
+ * Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org>
+ * Copyright (C) 2009-2020 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2009-2020 Milan Broz
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -19,16 +21,23 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <assert.h>
 #include <string.h>
 #include <stdlib.h>
-#include <fcntl.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <linux/fs.h>
 #include <unistd.h>
+#ifdef HAVE_SYS_SYSMACROS_H
+# include <sys/sysmacros.h>     /* for major, minor */
+#endif
+#ifdef HAVE_SYS_STATVFS_H
+# include <sys/statvfs.h>
+#endif
 #include "internal.h"
+#include "utils_device_locking.h"
 
 struct device {
 	char *path;
@@ -36,33 +45,323 @@ struct device {
 	char *file_path;
 	int loop_fd;
 
-	int init_done:1;
+	int ro_dev_fd;
+	int dev_fd;
+	int dev_fd_excl;
+
+	struct crypt_lock_handle *lh;
+
+	unsigned int o_direct:1;
+	unsigned int init_done:1; /* path is bdev or loop already initialized */
+
+	/* cached values */
+	size_t alignment;
+	size_t block_size;
 };
 
-static int device_ready(const char *device)
+static size_t device_fs_block_size_fd(int fd)
+{
+	size_t page_size = crypt_getpagesize();
+
+#ifdef HAVE_SYS_STATVFS_H
+	struct statvfs buf;
+
+	/*
+	 * NOTE: some filesystems (NFS) returns bogus blocksize (1MB).
+	 * Page-size io should always work and avoids increasing IO beyond aligned LUKS header.
+	 */
+	if (!fstatvfs(fd, &buf) && buf.f_bsize && buf.f_bsize <= page_size)
+		return (size_t)buf.f_bsize;
+#endif
+	return page_size;
+}
+
+static size_t device_block_size_fd(int fd, size_t *min_size)
+{
+	struct stat st;
+	size_t bsize;
+	int arg;
+
+	if (fstat(fd, &st) < 0)
+		return 0;
+
+	if (S_ISREG(st.st_mode))
+		bsize = device_fs_block_size_fd(fd);
+	else {
+		if (ioctl(fd, BLKSSZGET, &arg) < 0)
+			bsize = crypt_getpagesize();
+		else
+			bsize = (size_t)arg;
+	}
+
+	if (!min_size)
+		return bsize;
+
+	if (S_ISREG(st.st_mode)) {
+		/* file can be empty as well */
+		if (st.st_size > (ssize_t)bsize)
+			*min_size = bsize;
+		else
+			*min_size = st.st_size;
+	} else {
+		/* block device must have at least one block */
+		*min_size = bsize;
+	}
+
+	return bsize;
+}
+
+static size_t device_alignment_fd(int devfd)
+{
+	long alignment = DEFAULT_MEM_ALIGNMENT;
+
+#ifdef _PC_REC_XFER_ALIGN
+	alignment = fpathconf(devfd, _PC_REC_XFER_ALIGN);
+	if (alignment < 0)
+		alignment = DEFAULT_MEM_ALIGNMENT;
+#endif
+	return (size_t)alignment;
+}
+
+static int device_read_test(int devfd)
+{
+	char buffer[512];
+	int r = -EIO;
+	size_t minsize = 0, blocksize, alignment;
+
+	blocksize = device_block_size_fd(devfd, &minsize);
+	alignment = device_alignment_fd(devfd);
+
+	if (!blocksize || !alignment)
+		return -EINVAL;
+
+	if (minsize == 0)
+		return 0;
+
+	if (minsize > sizeof(buffer))
+		minsize = sizeof(buffer);
+
+	if (read_blockwise(devfd, blocksize, alignment, buffer, minsize) == (ssize_t)minsize)
+		r = 0;
+
+	crypt_safe_memzero(buffer, sizeof(buffer));
+	return r;
+}
+
+/*
+ * The direct-io is always preferred. The header is usually mapped to the same
+ * device and can be accessed when the rest of device is mapped to data device.
+ * Using direct-io ensures that we do not mess with data in cache.
+ * (But proper alignment should prevent this in the first place.)
+ * The read test is needed to detect broken configurations (seen with remote
+ * block devices) that allow open with direct-io but then fails on read.
+ */
+static int device_ready(struct crypt_device *cd, struct device *device)
 {
-	int devfd, r = 0;
+	int devfd = -1, r = 0;
 	struct stat st;
+	size_t tmp_size;
+
+	if (device->o_direct) {
+		log_dbg(cd, "Trying to open and read device %s with direct-io.",
+			device_path(device));
+		device->o_direct = 0;
+		devfd = open(device_path(device), O_RDONLY | O_DIRECT);
+		if (devfd >= 0) {
+			if (device_read_test(devfd) == 0) {
+				device->o_direct = 1;
+			} else {
+				close(devfd);
+				devfd = -1;
+			}
+		}
+	}
+
+	if (devfd < 0) {
+		log_dbg(cd, "Trying to open device %s without direct-io.",
+			device_path(device));
+		devfd = open(device_path(device), O_RDONLY);
+	}
 
-	log_dbg("Trying to open and read device %s.", device);
-	devfd = open(device, O_RDONLY | O_DIRECT | O_SYNC);
 	if (devfd < 0) {
-		log_err(NULL, _("Device %s doesn't exist or access denied.\n"), device);
+		log_err(cd, _("Device %s does not exist or access denied."),
+			device_path(device));
 		return -EINVAL;
 	}
+
 	if (fstat(devfd, &st) < 0)
 		r = -EINVAL;
 	else if (!S_ISBLK(st.st_mode))
 		r = S_ISREG(st.st_mode) ? -ENOTBLK : -EINVAL;
+	if (r == -EINVAL) {
+		log_err(cd, _("Device %s is not compatible."),
+			device_path(device));
+		close(devfd);
+		return r;
+	}
+
+	/* Allow only increase (loop device) */
+	tmp_size = device_alignment_fd(devfd);
+	if (tmp_size > device->alignment)
+		device->alignment = tmp_size;
+
+	tmp_size = device_block_size_fd(devfd, NULL);
+	if (tmp_size > device->block_size)
+		device->block_size = tmp_size;
 
 	close(devfd);
 	return r;
 }
 
-int device_alloc(struct device **device, const char *path)
+static int _open_locked(struct crypt_device *cd, struct device *device, int flags)
+{
+	int fd;
+
+	log_dbg(cd, "Opening locked device %s", device_path(device));
+
+	if ((flags & O_ACCMODE) != O_RDONLY && device_locked_readonly(device->lh)) {
+		log_dbg(cd, "Cannot open locked device %s in write mode. Read lock held.", device_path(device));
+		return -EAGAIN;
+	}
+
+	fd = open(device_path(device), flags);
+	if (fd < 0)
+		return -errno;
+
+	if (device_locked_verify(cd, fd, device->lh)) {
+		/* fd doesn't correspond to a locked resource */
+		close(fd);
+		log_dbg(cd, "Failed to verify lock resource for device %s.", device_path(device));
+		return -EINVAL;
+	}
+
+	return fd;
+}
+
+/*
+ * Common wrapper for device sync.
+ */
+void device_sync(struct crypt_device *cd, struct device *device)
+{
+	if (!device || device->dev_fd < 0)
+		return;
+
+	if (fsync(device->dev_fd) == -1)
+		log_dbg(cd, "Cannot sync device %s.", device_path(device));
+}
+
+/*
+ * in non-locked mode returns always fd or -1
+ *
+ * in locked mode:
+ * 	opened fd or one of:
+ * 	-EAGAIN : requested write mode while device being locked in via shared lock
+ * 	-EINVAL : invalid lock fd state
+ * 	-1	: all other errors
+ */
+static int device_open_internal(struct crypt_device *cd, struct device *device, int flags)
+{
+	int access, devfd;
+
+	if (device->o_direct)
+		flags |= O_DIRECT;
+
+	access = flags & O_ACCMODE;
+	if (access == O_WRONLY)
+		access = O_RDWR;
+
+	if (access == O_RDONLY && device->ro_dev_fd >= 0) {
+		log_dbg(cd, "Reusing open r%c fd on device %s", 'o', device_path(device));
+		return device->ro_dev_fd;
+	} else if (access == O_RDWR && device->dev_fd >= 0) {
+		log_dbg(cd, "Reusing open r%c fd on device %s", 'w', device_path(device));
+		return device->dev_fd;
+	}
+
+	if (device_locked(device->lh))
+		devfd = _open_locked(cd, device, flags);
+	else
+		devfd = open(device_path(device), flags);
+
+	if (devfd < 0) {
+		log_dbg(cd, "Cannot open device %s%s.",
+			device_path(device),
+			access != O_RDONLY ? " for write" : "");
+		return devfd;
+	}
+
+	if (access == O_RDONLY)
+		device->ro_dev_fd = devfd;
+	else
+		device->dev_fd = devfd;
+
+	return devfd;
+}
+
+int device_open(struct crypt_device *cd, struct device *device, int flags)
+{
+	assert(!device_locked(device->lh));
+	return device_open_internal(cd, device, flags);
+}
+
+int device_open_excl(struct crypt_device *cd, struct device *device, int flags)
+{
+	const char *path;
+	struct stat st;
+
+	if (!device)
+		return -EINVAL;
+
+	assert(!device_locked(device->lh));
+
+	if (device->dev_fd_excl < 0) {
+		path = device_path(device);
+		if (stat(path, &st))
+			return -EINVAL;
+		if (!S_ISBLK(st.st_mode))
+			log_dbg(cd, "%s is not a block device. Can't open in exclusive mode.",
+				path);
+		else {
+			/* open(2) with O_EXCL (w/o O_CREAT) on regular file is undefined behaviour according to man page */
+			/* coverity[toctou] */
+			device->dev_fd_excl = open(path, O_RDONLY | O_EXCL);
+			if (device->dev_fd_excl < 0)
+				return errno == EBUSY ? -EBUSY : device->dev_fd_excl;
+			if (fstat(device->dev_fd_excl, &st) || !S_ISBLK(st.st_mode)) {
+				log_dbg(cd, "%s is not a block device. Can't open in exclusive mode.",
+					path);
+				close(device->dev_fd_excl);
+				device->dev_fd_excl = -1;
+			} else
+				log_dbg(cd, "Device %s is blocked for exclusive open.", path);
+		}
+	}
+
+	return device_open_internal(cd, device, flags);
+}
+
+void device_release_excl(struct crypt_device *cd, struct device *device)
+{
+	if (device && device->dev_fd_excl >= 0) {
+		if (close(device->dev_fd_excl))
+			log_dbg(cd, "Failed to release exclusive handle on device %s.",
+				device_path(device));
+		else
+			log_dbg(cd, "Closed exclusive fd for %s.", device_path(device));
+		device->dev_fd_excl = -1;
+	}
+}
+
+int device_open_locked(struct crypt_device *cd, struct device *device, int flags)
+{
+	assert(!crypt_metadata_locking_enabled() || device_locked(device->lh));
+	return device_open_internal(cd, device, flags);
+}
+
+/* Avoid any read from device, expects direct-io to work. */
+int device_alloc_no_check(struct device **device, const char *path)
 {
 	struct device *dev;
-	int r;
 
 	if (!path) {
 		*device = NULL;
@@ -74,38 +373,66 @@ int device_alloc(struct device **device, const char *path)
 		return -ENOMEM;
 
 	memset(dev, 0, sizeof(struct device));
-	dev->loop_fd = -1;
-
-	r = device_ready(path);
-	if (!r) {
-		dev->init_done = 1;
-	} else if (r == -ENOTBLK) {
-		/* alloc loop later */
-	} else if (r < 0) {
-		free(dev);
-		return -ENOTBLK;
-	}
-
 	dev->path = strdup(path);
 	if (!dev->path) {
 		free(dev);
 		return -ENOMEM;
 	}
+	dev->loop_fd = -1;
+	dev->ro_dev_fd = -1;
+	dev->dev_fd = -1;
+	dev->dev_fd_excl = -1;
+	dev->o_direct = 1;
+
+	*device = dev;
+	return 0;
+}
+
+int device_alloc(struct crypt_device *cd, struct device **device, const char *path)
+{
+	struct device *dev;
+	int r;
+
+	r = device_alloc_no_check(&dev, path);
+	if (r < 0)
+		return r;
+
+	if (dev) {
+		r = device_ready(cd, dev);
+		if (!r) {
+			dev->init_done = 1;
+		} else if (r == -ENOTBLK) {
+			/* alloc loop later */
+		} else if (r < 0) {
+			free(dev->path);
+			free(dev);
+			return -ENOTBLK;
+		}
+	}
 
 	*device = dev;
 	return 0;
 }
 
-void device_free(struct device *device)
+void device_free(struct crypt_device *cd, struct device *device)
 {
 	if (!device)
 		return;
 
+	device_close(cd, device);
+
+	if (device->dev_fd_excl != -1) {
+		log_dbg(cd, "Closed exclusive fd for %s.", device_path(device));
+		close(device->dev_fd_excl);
+	}
+
 	if (device->loop_fd != -1) {
-		log_dbg("Closed loop %s (%s).", device->path, device->file_path);
+		log_dbg(cd, "Closed loop %s (%s).", device->path, device->file_path);
 		close(device->loop_fd);
 	}
 
+	assert(!device_locked(device->lh));
+
 	free(device->file_path);
 	free(device->path);
 	free(device);
@@ -120,6 +447,21 @@ const char *device_block_path(const struct device *device)
 	return device->path;
 }
 
+/* Get device-mapper name of device (if possible) */
+const char *device_dm_name(const struct device *device)
+{
+	const char *dmdir = dm_get_dir();
+	size_t dmdir_len = strlen(dmdir);
+
+	if (!device || !device->init_done)
+		return NULL;
+
+	if (strncmp(device->path, dmdir, dmdir_len))
+		return NULL;
+
+	return &device->path[dmdir_len+1];
+}
+
 /* Get path to device / file */
 const char *device_path(const struct device *device)
 {
@@ -139,10 +481,11 @@ const char *device_path(const struct device *device)
 #define BLKALIGNOFF _IO(0x12,122)
 #endif
 
-void device_topology_alignment(struct device *device,
-			    unsigned long *required_alignment, /* bytes */
-			    unsigned long *alignment_offset,   /* bytes */
-			    unsigned long default_alignment)
+void device_topology_alignment(struct crypt_device *cd,
+			       struct device *device,
+			       unsigned long *required_alignment, /* bytes */
+			       unsigned long *alignment_offset,   /* bytes */
+			       unsigned long default_alignment)
 {
 	int dev_alignment_offset = 0;
 	unsigned int min_io_size = 0, opt_io_size = 0;
@@ -161,7 +504,7 @@ void device_topology_alignment(struct device *device,
 
 	/* minimum io size */
 	if (ioctl(fd, BLKIOMIN, &min_io_size) == -1) {
-		log_dbg("Topology info for %s not supported, using default offset %lu bytes.",
+		log_dbg(cd, "Topology info for %s not supported, using default offset %lu bytes.",
 			device->path, default_alignment);
 		goto out;
 	}
@@ -177,44 +520,41 @@ void device_topology_alignment(struct device *device,
 
 	temp_alignment = (unsigned long)min_io_size;
 
-	if (temp_alignment < (unsigned long)opt_io_size)
+	/* Ignore bogus opt-io that could break alignment */
+	if ((temp_alignment < (unsigned long)opt_io_size) &&
+	    !((unsigned long)opt_io_size % temp_alignment))
 		temp_alignment = (unsigned long)opt_io_size;
 
 	/* If calculated alignment is multiple of default, keep default */
 	if (temp_alignment && (default_alignment % temp_alignment))
 		*required_alignment = temp_alignment;
 
-	log_dbg("Topology: IO (%u/%u), offset = %lu; Required alignment is %lu bytes.",
+	log_dbg(cd, "Topology: IO (%u/%u), offset = %lu; Required alignment is %lu bytes.",
 		min_io_size, opt_io_size, *alignment_offset, *required_alignment);
 out:
 	(void)close(fd);
 }
 
-int device_block_size(struct device *device)
+size_t device_block_size(struct crypt_device *cd, struct device *device)
 {
-	struct stat st;
-	int fd, bsize = 0, r = -EINVAL;
+	int fd;
 
 	if (!device)
 		return 0;
 
-	fd = open(device->path, O_RDONLY);
-	if(fd < 0)
-		return -EINVAL;
-
-	if (fstat(fd, &st) < 0)
-		goto out;
+	if (device->block_size)
+		return device->block_size;
 
-	if (S_ISREG(st.st_mode)) {
-		r = (int)crypt_getpagesize();
-		goto out;
+	fd = open(device->file_path ?: device->path, O_RDONLY);
+	if (fd >= 0) {
+		device->block_size = device_block_size_fd(fd, NULL);
+		close(fd);
 	}
 
-	if (ioctl(fd, BLKSSZGET, &bsize) >= 0)
-		r = bsize;
-out:
-	close(fd);
-	return r;
+	if (!device->block_size)
+		log_dbg(cd, "Cannot get block size for device %s.", device_path(device));
+
+	return device->block_size;
 }
 
 int device_read_ahead(struct device *device, uint32_t *read_ahead)
@@ -260,18 +600,72 @@ out:
 	return r;
 }
 
-static int device_info(struct device *device,
-			enum devcheck device_check,
-			int *readonly, uint64_t *size)
+/* For a file, allocate the required space */
+int device_fallocate(struct device *device, uint64_t size)
 {
 	struct stat st;
-	int fd, r = -EINVAL, flags = 0;
+	int devfd, r = -EINVAL;
+
+	devfd = open(device_path(device), O_RDWR);
+	if (devfd == -1)
+		return -EINVAL;
+
+	if (!fstat(devfd, &st) && S_ISREG(st.st_mode) &&
+	    ((uint64_t)st.st_size >= size || !posix_fallocate(devfd, 0, size))) {
+		r = 0;
+		if (device->file_path && crypt_loop_resize(device->path))
+			r = -EINVAL;
+	}
+
+	close(devfd);
+	return r;
+}
+
+int device_check_size(struct crypt_device *cd,
+		      struct device *device,
+		      uint64_t req_offset, int falloc)
+{
+	uint64_t dev_size;
 
-	*readonly = 0;
-	*size = 0;
+	if (device_size(device, &dev_size)) {
+		log_dbg(cd, "Cannot get device size for device %s.", device_path(device));
+		return -EIO;
+	}
+
+	log_dbg(cd, "Device size %" PRIu64 ", offset %" PRIu64 ".", dev_size, req_offset);
+
+	if (req_offset > dev_size) {
+		/* If it is header file, increase its size */
+		if (falloc && !device_fallocate(device, req_offset))
+			return 0;
 
-	if (stat(device->path, &st) < 0)
+		log_err(cd, _("Device %s is too small. Need at least %" PRIu64 " bytes."),
+			device_path(device), req_offset);
 		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int device_info(struct crypt_device *cd,
+		       struct device *device,
+		       enum devcheck device_check,
+		       int *readonly, uint64_t *size)
+{
+	struct stat st;
+	int fd = -1, r, flags = 0, real_readonly;
+	uint64_t real_size;
+
+	if (!device)
+		return -ENOTBLK;
+
+	real_readonly = 0;
+	real_size = 0;
+
+	if (stat(device->path, &st) < 0) {
+		r = -EINVAL;
+		goto out;
+	}
 
 	/* never wipe header on mounted device */
 	if (device_check == DEV_EXCL && S_ISBLK(st.st_mode))
@@ -281,77 +675,110 @@ static int device_info(struct device *device,
 	/* coverity[toctou] */
 	fd = open(device->path, O_RDWR | flags);
 	if (fd == -1 && errno == EROFS) {
-		*readonly = 1;
+		real_readonly = 1;
 		fd = open(device->path, O_RDONLY | flags);
 	}
 
-	if (fd == -1 && device_check == DEV_EXCL && errno == EBUSY)
-		return -EBUSY;
+	if (fd == -1 && device_check == DEV_EXCL && errno == EBUSY) {
+		r = -EBUSY;
+		goto out;
+	}
 
-	if (fd == -1)
-		return -EINVAL;
+	if (fd == -1) {
+		r = errno ? -errno : -EINVAL;
+		goto out;
+	}
 
+	r = 0;
 	if (S_ISREG(st.st_mode)) {
 		//FIXME: add readonly check
-		*size = (uint64_t)st.st_size;
-		*size >>= SECTOR_SHIFT;
+		real_size = (uint64_t)st.st_size;
+		real_size >>= SECTOR_SHIFT;
 	} else {
 		/* If the device can be opened read-write, i.e. readonly is still 0, then
 		 * check whether BKROGET says that it is read-only. E.g. read-only loop
-		 * devices may be openend read-write but are read-only according to BLKROGET
+		 * devices may be opened read-write but are read-only according to BLKROGET
 		 */
-		if (*readonly == 0 && (r = ioctl(fd, BLKROGET, readonly)) < 0)
+		if (real_readonly == 0 && (r = ioctl(fd, BLKROGET, &real_readonly)) < 0)
 			goto out;
 
-		if (ioctl(fd, BLKGETSIZE64, size) >= 0) {
-			*size >>= SECTOR_SHIFT;
-			r = 0;
+		r = ioctl(fd, BLKGETSIZE64, &real_size);
+		if (r >= 0) {
+			real_size >>= SECTOR_SHIFT;
 			goto out;
 		}
 	}
-	r = -EINVAL;
 out:
-	close(fd);
+	if (fd != -1)
+		close(fd);
+
+	switch (r) {
+	case 0:
+		if (readonly)
+			*readonly = real_readonly;
+		if (size)
+			*size = real_size;
+		break;
+	case -EBUSY:
+		log_err(cd, _("Cannot use device %s which is in use "
+			      "(already mapped or mounted)."), device_path(device));
+		break;
+	case -EACCES:
+		log_err(cd, _("Cannot use device %s, permission denied."), device_path(device));
+		break;
+	default:
+		log_err(cd, _("Cannot get info about device %s."), device_path(device));
+		r = -EINVAL;
+	}
+
 	return r;
 }
 
+int device_check_access(struct crypt_device *cd,
+			struct device *device,
+			enum devcheck device_check)
+{
+	return device_info(cd, device, device_check, NULL, NULL);
+}
+
 static int device_internal_prepare(struct crypt_device *cd, struct device *device)
 {
-	char *loop_device;
+	char *loop_device = NULL, *file_path = NULL;
 	int r, loop_fd, readonly = 0;
 
 	if (device->init_done)
 		return 0;
 
-	log_dbg("Allocating a free loop device.");
-	loop_device = crypt_loop_get_device();
-	if (!loop_device) {
-		if (getuid() || geteuid())
-			log_err(cd, _("Cannot use a loopback device, "
-				      "running as non-root user.\n"));
-		else
-			log_err(cd, _("Cannot find a free loopback device.\n"));
+	if (getuid() || geteuid()) {
+		log_err(cd, _("Cannot use a loopback device, "
+			      "running as non-root user."));
 		return -ENOTSUP;
 	}
 
-	/* Keep the loop open, dettached on last close. */
-	loop_fd = crypt_loop_attach(loop_device, device->path, 0, 1, &readonly);
+	log_dbg(cd, "Allocating a free loop device.");
+
+	/* Keep the loop open, detached on last close. */
+	loop_fd = crypt_loop_attach(&loop_device, device->path, 0, 1, &readonly);
 	if (loop_fd == -1) {
 		log_err(cd, _("Attaching loopback device failed "
-			"(loop device with autoclear flag is required).\n"));
+			"(loop device with autoclear flag is required)."));
 		free(loop_device);
 		return -EINVAL;
 	}
 
-	r = device_ready(loop_device);
+	file_path = device->path;
+	device->path = loop_device;
+
+	r = device_ready(cd, device);
 	if (r < 0) {
+		device->path = file_path;
+		crypt_loop_detach(loop_device);
 		free(loop_device);
 		return r;
 	}
 
 	device->loop_fd = loop_fd;
-	device->file_path = device->path;
-	device->path = loop_device;
+	device->file_path = file_path;
 	device->init_done = 1;
 
 	return 0;
@@ -374,28 +801,20 @@ int device_block_adjust(struct crypt_device *cd,
 	if (r)
 		return r;
 
-	r = device_info(device, device_check, &real_readonly, &real_size);
-	if (r < 0) {
-		if (r == -EBUSY)
-			log_err(cd, _("Cannot use device %s which is in use "
-				      "(already mapped or mounted).\n"),
-				      device->path);
-		else
-			log_err(cd, _("Cannot get info about device %s.\n"),
-				device->path);
+	r = device_info(cd, device, device_check, &real_readonly, &real_size);
+	if (r)
 		return r;
-	}
 
 	if (device_offset >= real_size) {
-		log_err(cd, _("Requested offset is beyond real size of device %s.\n"),
-			device->path);
+		log_err(cd, _("Requested offset is beyond real size of device %s."),
+			device_path(device));
 		return -EINVAL;
 	}
 
 	if (size && !*size) {
 		*size = real_size;
 		if (!*size) {
-			log_err(cd, _("Device %s has zero size.\n"), device->path);
+			log_err(cd, _("Device %s has zero size."), device_path(device));
 			return -ENOTBLK;
 		}
 		*size -= device_offset;
@@ -403,10 +822,10 @@ int device_block_adjust(struct crypt_device *cd,
 
 	/* in case of size is set by parameter */
 	if (size && ((real_size - device_offset) < *size)) {
-		log_dbg("Device %s: offset = %" PRIu64 " requested size = %" PRIu64
+		log_dbg(cd, "Device %s: offset = %" PRIu64 " requested size = %" PRIu64
 			", backing device size = %" PRIu64,
 			device->path, device_offset, *size, real_size);
-		log_err(cd, _("Device %s is too small.\n"), device->path);
+		log_err(cd, _("Device %s is too small."), device_path(device));
 		return -EINVAL;
 	}
 
@@ -414,13 +833,156 @@ int device_block_adjust(struct crypt_device *cd,
 		*flags |= CRYPT_ACTIVATE_READONLY;
 
 	if (size)
-		log_dbg("Calculated device size is %" PRIu64" sectors (%s), offset %" PRIu64 ".",
+		log_dbg(cd, "Calculated device size is %" PRIu64" sectors (%s), offset %" PRIu64 ".",
 		*size, real_readonly ? "RO" : "RW", device_offset);
 	return 0;
 }
 
-size_t size_round_up(size_t size, unsigned int block)
+size_t size_round_up(size_t size, size_t block)
 {
 	size_t s = (size + (block - 1)) / block;
 	return s * block;
 }
+
+void device_disable_direct_io(struct device *device)
+{
+	device->o_direct = 0;
+}
+
+int device_direct_io(const struct device *device)
+{
+	return device->o_direct;
+}
+
+static dev_t device_devno(const struct device *device)
+{
+	struct stat st;
+
+	if (stat(device->path, &st) || !S_ISBLK(st.st_mode))
+		return 0;
+
+	return st.st_rdev;
+}
+
+int device_is_identical(struct device *device1, struct device *device2)
+{
+	if (!device1 || !device2)
+		return 0;
+
+	if (device1 == device2)
+		return 1;
+
+	if (device1->init_done && device2->init_done)
+		return (device_devno(device1) == device_devno(device2));
+	else if (device1->init_done || device2->init_done)
+		return 0;
+
+	if (!strcmp(device_path(device1), device_path(device2)))
+		return 1;
+
+	return 0;
+}
+
+int device_is_rotational(struct device *device)
+{
+	struct stat st;
+
+	if (stat(device_path(device), &st) < 0)
+		return -EINVAL;
+
+	if (!S_ISBLK(st.st_mode))
+		return 0;
+
+	return crypt_dev_is_rotational(major(st.st_rdev), minor(st.st_rdev));
+}
+
+size_t device_alignment(struct device *device)
+{
+	int devfd;
+
+	if (!device->alignment) {
+		devfd = open(device_path(device), O_RDONLY);
+		if (devfd != -1) {
+			device->alignment = device_alignment_fd(devfd);
+			close(devfd);
+		}
+	}
+
+	return device->alignment;
+}
+
+void device_set_lock_handle(struct device *device, struct crypt_lock_handle *h)
+{
+	device->lh = h;
+}
+
+struct crypt_lock_handle *device_get_lock_handle(struct device *device)
+{
+	return device->lh;
+}
+
+int device_read_lock(struct crypt_device *cd, struct device *device)
+{
+	if (!crypt_metadata_locking_enabled())
+		return 0;
+
+	if (device_read_lock_internal(cd, device))
+		return -EBUSY;
+
+	return 0;
+}
+
+int device_write_lock(struct crypt_device *cd, struct device *device)
+{
+	if (!crypt_metadata_locking_enabled())
+		return 0;
+
+	assert(!device_locked(device->lh) || !device_locked_readonly(device->lh));
+
+	return device_write_lock_internal(cd, device);
+}
+
+void device_read_unlock(struct crypt_device *cd, struct device *device)
+{
+	if (!crypt_metadata_locking_enabled())
+		return;
+
+	assert(device_locked(device->lh));
+
+	device_unlock_internal(cd, device);
+}
+
+void device_write_unlock(struct crypt_device *cd, struct device *device)
+{
+	if (!crypt_metadata_locking_enabled())
+		return;
+
+	assert(device_locked(device->lh) && !device_locked_readonly(device->lh));
+
+	device_unlock_internal(cd, device);
+}
+
+bool device_is_locked(struct device *device)
+{
+	return device ? device_locked(device->lh) : 0;
+}
+
+void device_close(struct crypt_device *cd, struct device *device)
+{
+	if (!device)
+		return;
+
+	if (device->ro_dev_fd != -1) {
+		log_dbg(cd, "Closing read only fd for %s.", device_path(device));
+		if (close(device->ro_dev_fd))
+			log_dbg(cd, "Failed to close read only fd for %s.", device_path(device));
+		device->ro_dev_fd = -1;
+	}
+
+	if (device->dev_fd != -1) {
+		log_dbg(cd, "Closing read write fd for %s.", device_path(device));
+		if (close(device->dev_fd))
+			log_dbg(cd, "Failed to close read write fd for %s.", device_path(device));
+		device->dev_fd = -1;
+	}
+}