shithub: lwext4

Download patch

ref: e69f4b3ad8c1b56035b669e10072054ae2939695
parent: c3b3f743175a5827feacaa37bbc5443adc2c359b
author: gkostka <[email protected]>
date: Tue Dec 8 15:06:41 EST 2015

ext4_mbr: multiple changes related to MBR parsing

1. Introduce part_offset & part_size fields in blockdev
2. Blockdev operations with part_offset
3. Blockdev operations check based on part_size
4. lwext4_mbr tool: scan master boot record for linux partitions
5. Set right partition sizes in linux/windows file blockdevs

--- a/blockdev/linux/ext4_filedev.c
+++ b/blockdev/linux/ext4_filedev.c
@@ -74,7 +74,9 @@
 	if (fseeko(dev_file, 0, SEEK_END))
 		return EFAULT;
 
-	_filedev.bdif->ph_bcnt = ftell(dev_file) / _filedev.bdif->ph_bsize;
+	_filedev.part_offset = 0;
+	_filedev.part_size = ftell(dev_file);
+	_filedev.bdif->ph_bcnt = _filedev.part_size / _filedev.bdif->ph_bsize;
 
 	return EOK;
 }
--- a/blockdev/windows/io_raw.c
+++ b/blockdev/windows/io_raw.c
@@ -93,6 +93,9 @@
 	_filedev.bdif->ph_bsize = pdg.BytesPerSector;
 	_filedev.bdif->ph_bcnt = disk_size / pdg.BytesPerSector;
 
+	_filedev.part_offset = 0;
+	_filedev.part_size = disk_size;
+
 	return EOK;
 }
 
--- a/fs_test/CMakeLists.txt
+++ b/fs_test/CMakeLists.txt
@@ -18,4 +18,8 @@
 
 add_executable(lwext4_mkfs lwext4_mkfs.c)
 target_link_libraries(lwext4_mkfs blockdev)
-target_link_libraries(lwext4_mkfs lwext4)
\ No newline at end of file
+target_link_libraries(lwext4_mkfs lwext4)
+
+add_executable(lwext4_mbr lwext4_mbr.c)
+target_link_libraries(lwext4_mbr blockdev)
+target_link_libraries(lwext4_mbr lwext4)
\ No newline at end of file
--- /dev/null
+++ b/fs_test/lwext4_mbr.c
@@ -1,0 +1,183 @@
+/*
+ * Copyright (c) 2015 Grzegorz Kostka ([email protected])
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#include <ext4.h>
+#include <ext4_mbr.h>
+#include "../blockdev/linux/ext4_filedev.h"
+#include "../blockdev/windows/io_raw.h"
+
+/**@brief   Input stream name.*/
+const char *input_name = NULL;
+
+/**@brief   Block device handle.*/
+static struct ext4_blockdev *bd;
+
+/**@brief   Indicates that input is windows partition.*/
+static bool winpart = false;
+
+static bool verbose = false;
+
+static const char *usage = "                                    \n\
+Welcome in lwext4_mbr tool.                                     \n\
+Copyright (c) 2015 Grzegorz Kostka ([email protected])  \n\
+Usage:                                                          \n\
+[-i] --input   - input file name (or blockdevice)               \n\
+[-w] --wpart   - windows partition mode                         \n\
+[-v] --verbose - verbose mode		                        \n\
+\n";
+
+
+static bool open_linux(void)
+{
+	ext4_filedev_filename(input_name);
+	bd = ext4_filedev_get();
+	if (!bd) {
+		printf("open_filedev: fail\n");
+		return false;
+	}
+	return true;
+}
+
+static bool open_windows(void)
+{
+#ifdef WIN32
+	ext4_io_raw_filename(input_name);
+	bd = ext4_io_raw_dev_get();
+	if (!bd) {
+		printf("open_winpartition: fail\n");
+		return false;
+	}
+	return true;
+#else
+	printf("open_winpartition: this mode should be used only under windows "
+	       "!\n");
+	return false;
+#endif
+}
+
+static bool open_filedev(void)
+{
+	if (winpart) {
+		if (!open_windows())
+			return false;
+	} else {
+		if (!open_linux())
+			return false;
+	}
+
+	return true;
+}
+
+static bool parse_opt(int argc, char **argv)
+{
+	int option_index = 0;
+	int c;
+
+	static struct option long_options[] = {
+	    {"input", required_argument, 0, 'i'},
+	    {"wpart", no_argument, 0, 'w'},
+	    {"verbose", no_argument, 0, 'v'},
+	    {0, 0, 0, 0}};
+
+	while (-1 != (c = getopt_long(argc, argv, "i:wv",
+				      long_options, &option_index))) {
+
+		switch (c) {
+		case 'i':
+			input_name = optarg;
+			break;
+		case 'w':
+			winpart = true;
+			break;
+		case 'v':
+			verbose = true;
+			break;
+		default:
+			printf("%s", usage);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+int main(int argc, char **argv)
+{
+	int r;
+	if (!parse_opt(argc, argv)){
+		printf("parse_opt error\n");
+		return EXIT_FAILURE;
+	}
+
+	if (!open_filedev()) {
+		printf("open_filedev error\n");
+		return EXIT_FAILURE;
+	}
+
+	if (verbose)
+		ext4_dmask_set(DEBUG_ALL);
+
+	printf("ext4_mbr\n");
+	struct ext4_mbr_bdevs bdevs;
+	r = ext4_mbr_scan(bd, &bdevs);
+	if (r != EOK) {
+		printf("ext4_mbr_scan error\n");
+		return EXIT_FAILURE;
+	}
+
+	int i;
+	printf("ext4_mbr_scan:\n");
+	for (i = 0; i < 4; i++) {
+		printf("mbr_entry %d:\n", i);
+		if (!bdevs.partitions[i].bdif) {
+			printf("\tempty/unknown\n");
+			continue;
+		}
+
+		printf("\toffeset: 0x%llx, %lluMB\n",
+			bdevs.partitions[i].part_offset,
+			bdevs.partitions[i].part_offset / (1024 * 1024));
+		printf("\tsize: 0x%llx, %lluMB\n",
+			bdevs.partitions[i].part_size,
+			bdevs.partitions[i].part_size / (1024 * 1024));
+	}
+
+
+	return EXIT_SUCCESS;
+}
--- a/lwext4/ext4_blockdev.c
+++ b/lwext4/ext4_blockdev.c
@@ -116,7 +116,7 @@
 	ext4_assert(!(lb_bsize % bdev->bdif->ph_bsize));
 
 	bdev->lg_bsize = lb_bsize;
-	bdev->lg_bcnt = (bdev->bdif->ph_bcnt * bdev->bdif->ph_bsize) / lb_bsize;
+	bdev->lg_bcnt = bdev->part_size / lb_bsize;
 }
 
 int ext4_block_fini(struct ext4_blockdev *bdev)
@@ -256,8 +256,7 @@
 
 	ext4_assert(bdev && buf);
 
-	pba = (lba * bdev->lg_bsize) / bdev->bdif->ph_bsize;
-	pba += bdev->ph_blk_offset;
+	pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
 	pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 
 	bdev->bread_ctr++;
@@ -272,8 +271,7 @@
 
 	ext4_assert(bdev && buf);
 
-	pba = (lba * bdev->lg_bsize) / bdev->bdif->ph_bsize;
-	pba += bdev->ph_blk_offset;
+	pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
 	pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 
 	bdev->bwrite_ctr++;
@@ -284,7 +282,6 @@
 			  const void *buf, uint32_t len)
 {
 	uint64_t block_idx;
-	uint64_t block_end;
 	uint32_t blen;
 	uint32_t unalg;
 	int r = EOK;
@@ -296,12 +293,11 @@
 	if (!bdev->bdif->ph_refctr)
 		return EIO;
 
-	block_idx = (off / bdev->bdif->ph_bsize) + bdev->ph_blk_offset;
-	block_end = block_idx + len / bdev->bdif->ph_bsize;
-
-	if (!(block_end < bdev->bdif->ph_bcnt))
+	if (off + len > bdev->part_size)
 		return EINVAL; /*Ups. Out of range operation*/
 
+	block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
+
 	/*OK lets deal with the first possible unaligned block*/
 	unalg = (off & (bdev->bdif->ph_bsize - 1));
 	if (unalg) {
@@ -354,7 +350,6 @@
 			 uint32_t len)
 {
 	uint64_t block_idx;
-	uint64_t block_end;
 	uint32_t blen;
 	uint32_t unalg;
 	int r = EOK;
@@ -366,11 +361,10 @@
 	if (!bdev->bdif->ph_refctr)
 		return EIO;
 
-	block_idx = (off / bdev->bdif->ph_bsize) + bdev->ph_blk_offset;
-	block_end = block_idx + len / bdev->bdif->ph_bsize;
-
-	if (!(block_end < bdev->bdif->ph_bcnt))
+	if (off + len > bdev->part_size)
 		return EINVAL; /*Ups. Out of range operation*/
+
+	block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
 
 	/*OK lets deal with the first possible unaligned block*/
 	unalg = (off & (bdev->bdif->ph_bsize - 1));
--- a/lwext4/ext4_blockdev.h
+++ b/lwext4/ext4_blockdev.h
@@ -100,8 +100,11 @@
 	struct ext4_blockdev_iface *bdif;
 
 	/**@brief Offset in bdif. For multi partition mode.*/
-	uint64_t ph_blk_offset;
+	uint64_t part_offset;
 
+	/**@brief Part size in bdif. For multi partition mode.*/
+	uint64_t part_size;
+
 	/**@brief   Block cache.*/
 	struct ext4_bcache *bc;
 
@@ -138,6 +141,8 @@
 	};								       \
 	static struct ext4_blockdev __name = {                                 \
 		.bdif = &__name##_iface,                                       \
+		.part_offset = 0,                                              \
+		.part_size =  (__bcnt) * (__bsize),                            \
 	}
 
 /**@brief   Block device initialization.
--- a/lwext4/ext4_mbr.c
+++ b/lwext4/ext4_mbr.c
@@ -35,8 +35,12 @@
  */
 
 #include "ext4_config.h"
+#include "ext4_types.h"
+#include "ext4_debug.h"
 #include "ext4_mbr.h"
 
+#include <string.h>
+
 #define MBR_SIGNATURE 0xAA55
 
 struct ext4_part_entry {
@@ -54,6 +58,58 @@
 	uint16_t signature;
 } __attribute__((packed));
 
+
+int ext4_mbr_scan(struct ext4_blockdev *parent, struct ext4_mbr_bdevs *bdevs)
+{
+	int r;
+	int i;
+
+	ext4_dbg(DEBUG_MBR, DBG_INFO "ext4_mbr_scan\n");
+	memset(bdevs, 0, sizeof(struct ext4_mbr_bdevs));
+	r = ext4_block_init(parent);
+	if (r != EOK)
+		return r;
+
+	r = ext4_block_readbytes(parent, 0, parent->bdif->ph_bbuf, 512);
+	if (r != EOK) {
+		goto blockdev_fini;
+	}
+
+	const struct ext4_mbr *mbr = (void *)parent->bdif->ph_bbuf;
+
+	if (to_le16(mbr->signature) != MBR_SIGNATURE) {
+		ext4_dbg(DEBUG_MBR, DBG_ERROR "ext4_mbr_scan: unknown "
+			 "signature: 0x%x\n", to_le16(mbr->signature));
+		r = ENOENT;
+		goto blockdev_fini;
+	}
+
+
+	for (i = 0; i < 4; ++i) {
+		const struct ext4_part_entry *pe = &mbr->part_entry[i];
+		ext4_dbg(DEBUG_MBR, "mbr_part: %d\n", i);
+		ext4_dbg(DEBUG_MBR, "\tstatus: 0x%x\n", pe->status);
+		ext4_dbg(DEBUG_MBR, "\ttype 0x%x:\n", pe->type);
+		ext4_dbg(DEBUG_MBR, "\tfirst_lba: 0x%x\n", pe->first_lba);
+		ext4_dbg(DEBUG_MBR, "\tsectors: 0x%x\n", pe->sectors);
+
+		if (!pe->sectors)
+			continue;
+
+		if (pe->type != 0x83)
+			continue;
+
+		bdevs->partitions[i].bdif = parent->bdif;
+		bdevs->partitions[i].part_offset =
+				pe->first_lba * parent->bdif->ph_bsize;
+		bdevs->partitions[i].part_size =
+				(uint64_t)pe->sectors * parent->bdif->ph_bsize;
+	}
+
+	blockdev_fini:
+	ext4_block_fini(parent);
+	return r;
+}
 
 /**
  * @}
--- a/lwext4/ext4_mbr.h
+++ b/lwext4/ext4_mbr.h
@@ -46,7 +46,6 @@
 
 /**@brief Master boot record block devices descriptor*/
 struct ext4_mbr_bdevs {
-	uint32_t cnt;
 	struct ext4_blockdev partitions[4];
 };