ext4_utils: move superblock parsing to its own compilation unit

Move ext4_parse_sb to its own compilation unit so it can be used
from fs_mgr without pulling in all of libext4_utils' dependencies
when compiling with ld.bfd.

Change-Id: I185352ecea0e0d577b8cdddfd519f2826d631277

7 files changed, 107 insertions, 39 deletions

diff --git a/ext4_utils/Android.mk b/ext4_utils/Android.mk
index 6eba3b17..8cb04eb6 100644
--- a/ext4_utils/Android.mk
+++ b/ext4_utils/Android.mk
@@ -13,7 +13,8 @@ libext4_utils_src_files := \
     uuid.c \
     sha1.c \
     wipe.c \
-    crc16.c
+    crc16.c \
+    ext4_sb.c
 
 #
 # -- All host/targets including windows
diff --git a/ext4_utils/ext2simg.c b/ext4_utils/ext2simg.c
index f75b6c2c..77c3650f 100644
--- a/ext4_utils/ext2simg.c
+++ b/ext4_utils/ext2simg.c
@@ -68,7 +68,7 @@ static int read_ext(int fd)
 	if (ret != sizeof(sb))
 		critical_error("failed to read all of superblock");
 
-	ext4_parse_sb(&sb);
+	ext4_parse_sb_info(&sb);
 
 	ret = lseek64(fd, info.len, SEEK_SET);
 	if (ret < 0)
diff --git a/ext4_utils/ext4_sb.c b/ext4_utils/ext4_sb.c
new file mode 100644
index 00000000..1d527a10
--- /dev/null
+++ b/ext4_utils/ext4_sb.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#include <errno.h>
+
+#include "ext4_sb.h"
+
+int ext4_parse_sb(struct ext4_super_block *sb, struct fs_info *info)
+{
+	uint64_t len_blocks;
+
+        if (sb->s_magic != EXT4_SUPER_MAGIC)
+                return -EINVAL;
+
+        if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
+                return -EINVAL;
+
+	info->block_size = 1024 << sb->s_log_block_size;
+	info->blocks_per_group = sb->s_blocks_per_group;
+	info->inodes_per_group = sb->s_inodes_per_group;
+	info->inode_size = sb->s_inode_size;
+	info->inodes = sb->s_inodes_count;
+	info->feat_ro_compat = sb->s_feature_ro_compat;
+	info->feat_compat = sb->s_feature_compat;
+	info->feat_incompat = sb->s_feature_incompat;
+	info->bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks;
+	info->label = sb->s_volume_name;
+
+	len_blocks = ((uint64_t)sb->s_blocks_count_hi << 32) +
+                sb->s_blocks_count_lo;
+	info->len = (uint64_t)info->block_size * len_blocks;
+
+	return 0;
+}
diff --git a/ext4_utils/ext4_sb.h b/ext4_utils/ext4_sb.h
new file mode 100644
index 00000000..832fa333
--- /dev/null
+++ b/ext4_utils/ext4_sb.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#ifndef _EXT4_UTILS_EXT4_SB_H_
+#define _EXT4_UTILS_EXT4_SB_H_
+
+#include "ext4_kernel_headers.h"
+
+#define EXT4_SUPER_MAGIC 0xEF53
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct fs_info {
+	int64_t len;	/* If set to 0, ask the block device for the size,
+			 * if less than 0, reserve that much space at the
+			 * end of the partition, else use the size given. */
+	uint32_t block_size;
+	uint32_t blocks_per_group;
+	uint32_t inodes_per_group;
+	uint32_t inode_size;
+	uint32_t inodes;
+	uint32_t journal_blocks;
+	uint16_t feat_ro_compat;
+	uint16_t feat_compat;
+	uint16_t feat_incompat;
+	uint32_t bg_desc_reserve_blocks;
+	const char *label;
+	uint8_t no_journal;
+};
+
+int ext4_parse_sb(struct ext4_super_block *sb, struct fs_info *info);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/ext4_utils/ext4_utils.c b/ext4_utils/ext4_utils.c
index 8c9d9312..2c79da93 100644
--- a/ext4_utils/ext4_utils.c
+++ b/ext4_utils/ext4_utils.c
@@ -261,7 +261,7 @@ void ext4_queue_sb(void)
 	}
 }
 
-void ext4_parse_sb(struct ext4_super_block *sb)
+void ext4_parse_sb_info(struct ext4_super_block *sb)
 {
 	if (sb->s_magic != EXT4_SUPER_MAGIC)
 		error("superblock magic incorrect");
@@ -269,20 +269,7 @@ void ext4_parse_sb(struct ext4_super_block *sb)
 	if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
 		error("filesystem state not valid");
 
-	info.block_size = 1024 << sb->s_log_block_size;
-	info.blocks_per_group = sb->s_blocks_per_group;
-	info.inodes_per_group = sb->s_inodes_per_group;
-	info.inode_size = sb->s_inode_size;
-	info.inodes = sb->s_inodes_count;
-	info.feat_ro_compat = sb->s_feature_ro_compat;
-	info.feat_compat = sb->s_feature_compat;
-	info.feat_incompat = sb->s_feature_incompat;
-	info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks;
-	info.label = sb->s_volume_name;
-
-	aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) +
-			sb->s_blocks_count_lo;
-	info.len = (u64)info.block_size * aux_info.len_blocks;
+	ext4_parse_sb(sb, &info);
 
 	ext4_create_fs_aux_info();
 
diff --git a/ext4_utils/ext4_utils.h b/ext4_utils/ext4_utils.h
index 298fc352..9b5b7c4a 100644
--- a/ext4_utils/ext4_utils.h
+++ b/ext4_utils/ext4_utils.h
@@ -45,7 +45,7 @@ extern "C" {
 #define off64_t off_t
 #endif
 
-#include "ext4_kernel_headers.h"
+#include "ext4_sb.h"
 
 extern int force;
 
@@ -55,7 +55,6 @@ extern int force;
 #define critical_error(fmt, args...) do { fprintf(stderr, "critical error: %s: " fmt "\n", __func__, ## args); longjmp(setjmp_env, EXIT_FAILURE); } while (0)
 #define critical_error_errno(s, args...) critical_error(s ": %s", ##args, strerror(errno))
 
-#define EXT4_SUPER_MAGIC 0xEF53
 #define EXT4_JNL_BACKUP_BLOCKS 1
 
 #ifndef min /* already defined by windows.h */
@@ -93,24 +92,6 @@ struct ext2_group_desc {
 	u16 bg_checksum;
 };
 
-struct fs_info {
-	s64 len;	/* If set to 0, ask the block device for the size,
-			 * if less than 0, reserve that much space at the
-			 * end of the partition, else use the size given. */
-	u32 block_size;
-	u32 blocks_per_group;
-	u32 inodes_per_group;
-	u32 inode_size;
-	u32 inodes;
-	u32 journal_blocks;
-	u16 feat_ro_compat;
-	u16 feat_compat;
-	u16 feat_incompat;
-	u32 bg_desc_reserve_blocks;
-	const char *label;
-	u8 no_journal;
-};
-
 struct fs_aux_info {
 	struct ext4_super_block *sb;
 	struct ext4_super_block **backup_sb;
@@ -156,7 +137,7 @@ void ext4_queue_sb(void);
 u64 get_block_device_size(int fd);
 u64 get_file_size(int fd);
 u64 parse_num(const char *arg);
-void ext4_parse_sb(struct ext4_super_block *sb);
+void ext4_parse_sb_info(struct ext4_super_block *sb);
 u16 ext4_crc16(u16 crc_in, const void *buf, int size);
 
 typedef void (*fs_config_func_t)(const char *path, int dir, unsigned *uid, unsigned *gid,
diff --git a/ext4_utils/ext4fixup.c b/ext4_utils/ext4fixup.c
index d271116c..7cf1f0ea 100644
--- a/ext4_utils/ext4fixup.c
+++ b/ext4_utils/ext4fixup.c
@@ -203,7 +203,7 @@ static int read_ext(int fd)
 
     read_sb(fd, &sb);
 
-    ext4_parse_sb(&sb);
+    ext4_parse_sb_info(&sb);
 
     if (info.feat_incompat & EXT4_FEATURE_INCOMPAT_RECOVER) {
         critical_error("Filesystem needs recovery first, mount and unmount to do that\n");