ext4: Check for return value from sb_set_blocksize

sb_set_blocksize validates whether the specfied block size can be used by
the file system. Make sure we fail mounting the file system if the
blocksize specfied cannot be used.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>

fs/ext4/super.c

@@ -1812,7 +1812,6 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	unsigned long def_mount_opts;
 	struct inode *root;
 	int blocksize;
-	int hblock;
 	int db_count;
 	int i;
 	int needs_recovery;
@@ -1969,20 +1968,16 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
-	hblock = bdev_hardsect_size(sb->s_bdev);
 	if (sb->s_blocksize != blocksize) {
-		/*
-		 * Make sure the blocksize for the filesystem is larger
-		 * than the hardware sectorsize for the machine.
-		 */
-		if (blocksize < hblock) {
-			printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
-			       "device blocksize %d.\n", blocksize, hblock);
+
+		/* Validate the filesystem blocksize */
+		if (!sb_set_blocksize(sb, blocksize)) {
+			printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
+					blocksize);
 			goto failed_mount;
 		}
 
 		brelse (bh);
-		sb_set_blocksize(sb, blocksize);
 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
 		offset = do_div(logical_sb_block, blocksize);
 		bh = sb_bread(sb, logical_sb_block);