Support topology information for data alignment (LUKS).

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@195 36d66b0a-2a48-0410-832c-cd162a569da5

ChangeLog

@@ -1,5 +1,6 @@
 2010-04-06  Milan Broz  <mbroz@redhat.com>
 	* Prefer some device paths in status display.
+	* Support device topology detectionfor data alignment.
 
 2010-02-25  Milan Broz  <mbroz@redhat.com>
 	* Do not verify unlocking passphrase in luksAddKey command.

lib/internal.h

@@ -120,4 +120,9 @@ void debug_processes_using_device(const char *name);
 int crypt_memlock_inc(struct crypt_device *ctx);
 int crypt_memlock_dec(struct crypt_device *ctx);
 
+void get_topology_alignment(const char *device,
+			    unsigned long *required_alignment, /* bytes */
+			    unsigned long *alignment_offset,   /* bytes */
+			    unsigned long default_alignment);
+
 #endif /* INTERNAL_H */

lib/setup.c

@@ -1092,16 +1092,25 @@ static int _crypt_format_luks1(struct crypt_device *cd,
 			       struct crypt_params_luks1 *params)
 {
 	int r;
+	unsigned long required_alignment = DEFAULT_ALIGNMENT;
+	unsigned long alignment_offset = 0;
 
 	if (!cd->device) {
 		log_err(cd, _("Can't format LUKS without device.\n"));
 		return -EINVAL;
 	}
 
+	if (params && params->data_alignment)
+		required_alignment = params->data_alignment * SECTOR_SIZE;
+	else
+		get_topology_alignment(cd->device, &required_alignment,
+				       &alignment_offset, DEFAULT_ALIGNMENT);
+
 	r = LUKS_generate_phdr(&cd->hdr, cd->volume_key, cipher, cipher_mode,
 			       (params && params->hash) ? params->hash : "sha1",
 			       uuid, LUKS_STRIPES,
-			       params ? params->data_alignment: DEFAULT_ALIGNMENT,
+			       required_alignment / SECTOR_SIZE,
+			       alignment_offset / SECTOR_SIZE,
 			       cd->iteration_time, &cd->PBKDF2_per_sec, cd);
 	if(r < 0)
 		return r;

lib/utils.c

@@ -683,3 +683,57 @@ int crypt_memlock_dec(struct crypt_device *ctx)
 	}
 	return _memlock_count ? 1 : 0;
 }
+
+/* DEVICE TOPOLOGY */
+
+/* block device topology ioctls, introduced in 2.6.32 */
+#ifndef BLKIOMIN
+#define BLKIOMIN    _IO(0x12,120)
+#define BLKIOOPT    _IO(0x12,121)
+#define BLKALIGNOFF _IO(0x12,122)
+#endif
+
+void get_topology_alignment(const char *device,
+			    unsigned long *required_alignment, /* bytes */
+			    unsigned long *alignment_offset,   /* bytes */
+			    unsigned long default_alignment)
+{
+	unsigned int dev_alignment_offset = 0;
+	unsigned long min_io_size = 0, opt_io_size = 0;
+	int fd;
+
+	*required_alignment = default_alignment;
+	*alignment_offset = 0;
+
+	fd = open(device, O_RDONLY);
+	if (fd == -1)
+		return;
+
+	/* minimum io size */
+	if (ioctl(fd, BLKIOMIN, &min_io_size) == -1) {
+		log_dbg("Topology info for %s not supported, using default offset %lu bytes.",
+			device, default_alignment);
+		return;
+	}
+
+	/* optimal io size */
+	if (ioctl(fd, BLKIOOPT, &opt_io_size) == -1)
+		opt_io_size = min_io_size;
+
+	/* alignment offset, bogus -1 means misaligned/unknown */
+	if (ioctl(fd, BLKALIGNOFF, &dev_alignment_offset) == -1 || (int)dev_alignment_offset < 0)
+		dev_alignment_offset = 0;
+
+	if (*required_alignment < min_io_size)
+		*required_alignment = min_io_size;
+
+	if (*required_alignment < opt_io_size)
+		*required_alignment = opt_io_size;
+
+	*alignment_offset = (unsigned long)dev_alignment_offset;
+
+	log_dbg("Topology: IO (%lu/%lu), offset = %lu; Required alignment is %lu bytes.",
+		min_io_size, opt_io_size, *alignment_offset, *required_alignment);
+
+	(void)close(fd);
+}

luks/keymanage.c

@@ -424,6 +424,7 @@ int LUKS_generate_phdr(struct luks_phdr *header,
 		       const char *cipherName, const char *cipherMode, const char *hashSpec,
 		       const char *uuid, unsigned int stripes,
 		       unsigned int alignPayload,
+		       unsigned int alignOffset,
 		       uint32_t iteration_time_ms,
 		       uint64_t *PBKDF2_per_sec,
 		       struct crypt_device *ctx)
@@ -488,7 +489,8 @@ int LUKS_generate_phdr(struct luks_phdr *header,
 	}
 	currentSector = round_up_modulo(currentSector, alignPayload);
 
-	header->payloadOffset=currentSector;
+	/* alignOffset - offset from natural device alignment provided by topology info */
+	header->payloadOffset = currentSector + alignOffset;
 
 	if (uuid && !uuid_parse(uuid, partitionUuid)) {
 		log_err(ctx, _("Wrong UUID format provided, generating new one.\n"));

luks/luks.h

@@ -91,6 +91,7 @@ int LUKS_generate_phdr(
 	const char *uuid,
 	unsigned int stripes,
 	unsigned int alignPayload,
+	unsigned int alignOffset,
 	uint32_t iteration_time_ms,
 	uint64_t *PBKDF2_per_sec,
 	struct crypt_device *ctx);

tests/align_test

@@ -0,0 +1,76 @@
+#!/bin/bash
+
+CRYPTSETUP="../src/cryptsetup"
+DEV=""
+
+add_device() {
+	modprobe scsi_debug $@
+	DEV=/dev/$(grep scsi_debug /sys/block/*/device/model | cut -f4 -d /)
+	sleep 2
+	[ -b $DEV ] || exit 100
+}
+
+cleanup() {
+	udevadm settle
+	rmmod scsi_debug 2>/dev/null
+	sleep 2
+}
+
+format() # key_bits expected [forced]
+{
+	if [ -z "$3" ] ; then
+		echo -n "Formatting using topology info ($1 bits key)...."
+		echo xxx| $CRYPTSETUP luksFormat $DEV -q -s $1
+	else
+		echo -n "Formatting using forced offset $3 ($1 bits key)..."
+		echo xxx| $CRYPTSETUP luksFormat $DEV -q -s $1 --align-payload=$2
+	fi
+
+	ALIGN=$($CRYPTSETUP luksDump $DEV |grep "Payload offset" | sed -e s/.*\\t//)
+	#echo "ALIGN = $ALIGN"
+
+	if [ $ALIGN -ne $2 ] ; then
+		echo "FAIL"
+		echo "Expected alignment differs: expected $2 != detected $ALIGN"
+		exit 100
+	fi
+	echo "PASSED"
+}
+
+modprobe --dry-run scsi_debug || exit 0
+cleanup
+
+echo "# Create desktop-class 4K drive"
+echo "# (logical_block_size=512, physical_block_size=4096, alignment_offset=0)"
+add_device dev_size_mb=16 sector_size=512 physblk_exp=3 num_tgts=1
+format 256 2112
+format 128 1088
+format 256 8192 8192
+format 128 8192 8192
+cleanup
+
+echo "# Create desktop-class 4K drive w/ 63-sector DOS partition compensation"
+echo "# (logical_block_size=512, physical_block_size=4096, alignment_offset=3584)"
+add_device dev_size_mb=16 sector_size=512 physblk_exp=3 lowest_aligned=7 num_tgts=1
+format 256 2119
+format 128 1095
+cleanup
+
+echo "# Create enterprise-class 4K drive"
+echo "# (logical_block_size=4096, physical_block_size=4096, alignment_offset=0)"
+add_device dev_size_mb=16 sector_size=4096 num_tgts=1
+format 256 2560
+format 128 1536 
+cleanup
+
+echo "# Create classic 512b drive and stack dm-linear"
+echo "# (logical_block_size=512, physical_block_size=512, alignment_offset=0)"
+add_device dev_size_mb=16 sector_size=512 num_tgts=1
+DEV2=$DEV
+DEV=/dev/mapper/luks0xbabe
+dmsetup create luks0xbabe --table "0 32768 linear $DEV2 0"
+format 256 2112
+format 128 1088
+format 128 8192 8192
+dmsetup remove luks0xbabe
+cleanup