fs:ext4:fix: Code refactoring to suppress compiler warnings

Several fixes to suppress compiler's (eldk-5.[12].x  gcc 4.6)
warning  [-Wunused-but-set-variable]

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 323875f..f12b805 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -378,7 +378,6 @@
 	struct ext_filesystem *fs = get_fs();
 	/* directory entry */
 	struct ext2_dirent *dir;
-	char *ptr = NULL;
 	char *temp_dir = NULL;
 
 	zero_buffer = zalloc(fs->blksz);
@@ -415,7 +414,6 @@
 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
 		goto fail;
 	dir = (struct ext2_dirent *)root_first_block_buffer;
-	ptr = (char *)dir;
 	totalbytes = 0;
 	while (dir->direntlen > 0) {
 		/*
@@ -483,14 +481,12 @@
 			break;
 
 		dir = (struct ext2_dirent *)((char *)dir + templength);
-		ptr = (char *)dir;
 	}
 
 	/* make a pointer ready for creating next directory entry */
 	templength = dir->direntlen;
 	totalbytes = totalbytes + templength;
 	dir = (struct ext2_dirent *)((char *)dir + templength);
-	ptr = (char *)dir;
 
 	/* get the next available inode number */
 	inodeno = ext4fs_get_new_inode_no();
@@ -1200,6 +1196,11 @@
 		status = ext4fs_devread(di_blockno_parent *
 					fs->sect_perblk, 0,
 					fs->blksz, (char *)di_parent_buffer);
+
+		if (!status) {
+			printf("%s: Device read error!\n", __func__);
+			goto fail;
+		}
 		memset(di_parent_buffer, '\0', fs->blksz);
 
 		/*
@@ -1227,6 +1228,11 @@
 						fs->sect_perblk, 0,
 						fs->blksz,
 						(char *)di_child_buff);
+
+			if (!status) {
+				printf("%s: Device read error!\n", __func__);
+				goto fail;
+			}
 			memset(di_child_buff, '\0', fs->blksz);
 			/* filling of actual datablocks for each child */
 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
diff --git a/fs/ext4/ext4_journal.c b/fs/ext4/ext4_journal.c
index 8a252d6..9f01708 100644
--- a/fs/ext4/ext4_journal.c
+++ b/fs/ext4/ext4_journal.c
@@ -410,7 +410,7 @@
 	int transaction_state = TRANSACTION_COMPLETE;
 	int prev_desc_logical_no = 0;
 	int curr_desc_logical_no = 0;
-	int ofs, flags, block;
+	int ofs, flags;
 	struct ext2_inode inode_journal;
 	struct journal_superblock_t *jsb = NULL;
 	struct journal_header_t *jdb = NULL;
@@ -453,7 +453,6 @@
 
 	i = be32_to_cpu(jsb->s_first);
 	while (1) {
-		block = be32_to_cpu(jsb->s_first);
 		blknr = read_allocated_block(&inode_journal, i);
 		memset(temp_buff1, '\0', fs->blksz);
 		ext4fs_devread(blknr * fs->sect_perblk,
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 80b3b90..64d8a6d 100644
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -931,7 +931,6 @@
 	int previous_block_number = -1;
 	int delayed_start = 0;
 	int delayed_extent = 0;
-	int delayed_skipfirst = 0;
 	int delayed_next = 0;
 	char *delayed_buf = NULL;
 
@@ -964,7 +963,6 @@
 					previous_block_number = blknr;
 					delayed_start = blknr;
 					delayed_extent = blockend;
-					delayed_skipfirst = skipfirst;
 					delayed_buf = buf;
 					delayed_next = blknr +
 					    (blockend >> SECTOR_BITS);
@@ -973,7 +971,6 @@
 				previous_block_number = blknr;
 				delayed_start = blknr;
 				delayed_extent = blockend;
-				delayed_skipfirst = skipfirst;
 				delayed_buf = buf;
 				delayed_next = blknr +
 				    (blockend >> SECTOR_BITS);