266 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			266 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * volume_id - reads filesystem label and uuid
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|  *
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|  * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
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|  *
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|  *	This library is free software; you can redistribute it and/or
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|  *	modify it under the terms of the GNU Lesser General Public
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|  *	License as published by the Free Software Foundation; either
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|  *	version 2.1 of the License, or (at your option) any later version.
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|  *
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|  *	This library is distributed in the hope that it will be useful,
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|  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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|  *	Lesser General Public License for more details.
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|  *
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|  *	You should have received a copy of the GNU Lesser General Public
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|  *	License along with this library; if not, write to the Free Software
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|  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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|  */
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| 
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| #include "volume_id_internal.h"
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| 
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| void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
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| {
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| 	unsigned i, j;
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| 	unsigned c;
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| 
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| 	j = 0;
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| 	for (i = 0; i + 2 <= count; i += 2) {
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| 		if (endianess == LE)
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| 			c = (buf[i+1] << 8) | buf[i];
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| 		else
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| 			c = (buf[i] << 8) | buf[i+1];
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| 		if (c == 0)
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| 			break;
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| 		if (j+1 >= len)
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| 			break;
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| 		if (c < 0x80) {
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| 			/* 0xxxxxxx */
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| 		} else {
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| 			uint8_t topbits = 0xc0;
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| 			if (j+2 >= len)
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| 				break;
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| 			if (c < 0x800) {
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| 				/* 110yyyxx 10xxxxxx */
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| 			} else {
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| 				if (j+3 >= len)
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| 					break;
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| 				/* 1110yyyy 10yyyyxx 10xxxxxx */
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| 				str[j++] = (uint8_t) (0xe0 | (c >> 12));
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| 				topbits = 0x80;
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| 			}
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| 			str[j++] = (uint8_t) (topbits | ((c >> 6) & 0x3f));
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| 			c = 0x80 | (c & 0x3f);
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| 		}
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| 		str[j++] = (uint8_t) c;
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| 	}
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| 	str[j] = '\0';
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| }
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| 
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| #ifdef UNUSED
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| static const char *usage_to_string(enum volume_id_usage usage_id)
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| {
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| 	switch (usage_id) {
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| 	case VOLUME_ID_FILESYSTEM:
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| 		return "filesystem";
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| 	case VOLUME_ID_PARTITIONTABLE:
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| 		return "partitiontable";
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| 	case VOLUME_ID_OTHER:
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| 		return "other";
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| 	case VOLUME_ID_RAID:
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| 		return "raid";
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| 	case VOLUME_ID_DISKLABEL:
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| 		return "disklabel";
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| 	case VOLUME_ID_CRYPTO:
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| 		return "crypto";
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| 	case VOLUME_ID_UNPROBED:
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| 		return "unprobed";
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| 	case VOLUME_ID_UNUSED:
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| 		return "unused";
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| 	}
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| 	return NULL;
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| }
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| 
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| void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
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| {
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| 	part->usage_id = usage_id;
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| 	part->usage = usage_to_string(usage_id);
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| }
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| 
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| void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
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| {
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| 	id->usage_id = usage_id;
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| 	id->usage = usage_to_string(usage_id);
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| }
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| 
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| void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
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| {
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| 	memcpy(id->label_raw, buf, count);
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| 	id->label_raw_len = count;
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| }
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| #endif
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| 
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| #ifdef NOT_NEEDED
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| static size_t strnlen(const char *s, size_t maxlen)
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| {
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| 	size_t i;
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| 	if (!maxlen) return 0;
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| 	if (!s) return 0;
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| 	for (i = 0; *s && i < maxlen; ++s) ++i;
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| 	return i;
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| }
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| #endif
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| 
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| void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
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| {
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| 	unsigned i;
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| 
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| 	memcpy(id->label, buf, count);
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| 
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| 	/* remove trailing whitespace */
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| 	i = strnlen(id->label, count);
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| 	while (i--) {
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| 		if (!isspace(id->label[i]))
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| 			break;
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| 	}
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| 	id->label[i+1] = '\0';
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| }
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| 
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| void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
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| {
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| 	volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
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| }
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| 
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| void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
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| {
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| 	unsigned i;
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| 	unsigned count = (format == UUID_DCE_STRING ? VOLUME_ID_UUID_SIZE : 4 << format);
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| 
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| //	memcpy(id->uuid_raw, buf, count);
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| //	id->uuid_raw_len = count;
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| 
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| 	/* if set, create string in the same format, the native platform uses */
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| 	for (i = 0; i < count; i++)
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| 		if (buf[i] != 0)
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| 			goto set;
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| 	return; /* all bytes are zero, leave it empty ("") */
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| 
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| set:
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| 	switch (format) {
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| 	case UUID_DOS:
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| 		sprintf(id->uuid, "%02X%02X-%02X%02X",
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| 			buf[3], buf[2], buf[1], buf[0]);
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| 		break;
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| 	case UUID_NTFS:
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| 		sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
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| 			buf[7], buf[6], buf[5], buf[4],
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| 			buf[3], buf[2], buf[1], buf[0]);
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| 		break;
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| 	case UUID_DCE:
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| 		sprintf(id->uuid,
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| 			"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
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| 			buf[0], buf[1], buf[2], buf[3],
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| 			buf[4], buf[5],
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| 			buf[6], buf[7],
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| 			buf[8], buf[9],
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| 			buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
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| 		break;
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| 	case UUID_DCE_STRING:
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| 		memcpy(id->uuid, buf, count);
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| 		id->uuid[count] = '\0';
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| 		break;
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| 	}
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| }
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| 
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| /* Do not use xlseek here. With it, single corrupted filesystem
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|  * may result in attempt to seek past device -> exit.
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|  * It's better to ignore such fs and continue.  */
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| void *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
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| {
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| 	uint8_t *dst;
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| 	unsigned small_off;
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| 	ssize_t read_len;
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| 
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| 	dbg("get buffer off 0x%llx(%llu), len 0x%zx",
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| 		(unsigned long long) off, (unsigned long long) off, len);
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| 
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| 	/* check if requested area fits in superblock buffer */
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| 	if (off + len <= SB_BUFFER_SIZE
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| 	 /* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */
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| 	) {
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| 		if (id->sbbuf == NULL) {
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| 			id->sbbuf = xmalloc(SB_BUFFER_SIZE);
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| 		}
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| 		small_off = off;
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| 		dst = id->sbbuf;
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| 
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| 		/* check if we need to read */
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| 		len += off;
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| 		if (len <= id->sbbuf_len)
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| 			goto ret; /* we already have it */
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| 
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| 		dbg("read sbbuf len:0x%x", (unsigned) len);
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| 		id->sbbuf_len = len;
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| 		off = 0;
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| 		goto do_read;
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| 	}
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| 
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| 	if (len > SEEK_BUFFER_SIZE) {
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| 		dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
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| 		return NULL;
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| 	}
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| 	dst = id->seekbuf;
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| 
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| 	/* check if we need to read */
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| 	if ((off >= id->seekbuf_off)
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| 	 && ((off + len) <= (id->seekbuf_off + id->seekbuf_len))
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| 	) {
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| 		small_off = off - id->seekbuf_off; /* can't overflow */
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| 		goto ret; /* we already have it */
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| 	}
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| 
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| 	id->seekbuf_off = off;
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| 	id->seekbuf_len = len;
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| 	id->seekbuf = xrealloc(id->seekbuf, len);
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| 	small_off = 0;
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| 	dst = id->seekbuf;
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| 	dbg("read seekbuf off:0x%llx len:0x%zx",
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| 				(unsigned long long) off, len);
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|  do_read:
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| 	if (lseek(id->fd, off, SEEK_SET) != off) {
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| 		dbg("seek(0x%llx) failed", (unsigned long long) off);
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| 		goto err;
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| 	}
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| 	read_len = full_read(id->fd, dst, len);
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| 	if (read_len != len) {
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| 		dbg("requested 0x%x bytes, got 0x%x bytes",
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| 				(unsigned) len, (unsigned) read_len);
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|  err:
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| 		/* No filesystem can be this tiny. It's most likely
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| 		 * non-associated loop device, empty drive and so on.
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| 		 * Flag it, making it possible to short circuit future
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| 		 * accesses. Rationale:
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| 		 * users complained of slow blkid due to empty floppy drives.
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| 		 */
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| 		if (off < 64*1024)
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| 			id->error = 1;
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| 		/* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing. */
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| 		volume_id_free_buffer(id);
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| 		return NULL;
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| 	}
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|  ret:
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| 	return dst + small_off;
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| }
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| 
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| void volume_id_free_buffer(struct volume_id *id)
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| {
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| 	free(id->sbbuf);
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| 	id->sbbuf = NULL;
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| 	id->sbbuf_len = 0;
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| 	free(id->seekbuf);
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| 	id->seekbuf = NULL;
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| 	id->seekbuf_len = 0;
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| 	id->seekbuf_off = 0; /* paranoia */
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| }
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