HowTo check and mark badblocks on ext4 Partitions

My storage is acting weird today and i'm trying to fix it with this command:
~# fsck.ext4 -vcDfty -C 0 /dev/sdb1
e2fsck 1.42.3 (14-May-2012)
Checking for bad blocks (read-only test): 19.10% done, 25:33 elapsed. (0/0/0 errors)

and this was the result:

***** FILE SYSTEM WAS MODIFIED *****
307426 inodes used (0.50%)
2114 non-contiguous files (0.7%)
133 non-contiguous directories (0.0%)
# of inodes with ind/dind/tind blocks: 0/0/0
Extent depth histogram: 304093/1528/2
210058537 blocks used (86.02%)
1 bad block
10 large files
--------
273702 regular files
31716 directories
57 character device files
26 block device files
2 fifos
0 links
1871 symbolic links (1665 fast symbolic links)
29 sockets
--------
307403 files
Memory used: 9168k/240k (1758k/7411k), time: 9906.96/45.67/ 1.40
I/O read: 472MB, write: 171MB, rate: 0.06MB/s

1 bad block marked