journal corrupted on / filesystem

[Jordi Prats]

Hi,
I'm getting this errors on the / filesystem:

Jul  3 08:03:54 inf04 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 18448395
Jul  3 08:03:54 inf04 kernel: Aborting journal on device cciss/c0d0p2.
Jul  3 08:03:54 inf04 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 18448387
Jul  3 08:03:55 inf04 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 18448387
Jul  3 08:03:55 inf04 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 18448395
Jul  3 08:03:57 inf04 kernel: ext3_abort called.
Jul  3 08:03:57 inf04 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_journal_start_sb: Detected aborted journal
Jul  3 08:03:57 inf04 kernel: Remounting filesystem read-only
(...)
Jul  3 08:04:30 inf05 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 49464569
Jul  3 08:04:30 inf05 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 49464569
Jul  3 08:04:30 inf05 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 49464569
Jul  3 08:04:30 inf05 kernel: EXT3-fs error (device cciss/c0d0p2): 
ext3_get_inode_block: bad inode number: 49464569

I supose I should remove the journal (get it back to ext2) and recreate 
it (tune2fs -j /dev/...) It's possible to do it without rebooting it? 
It's no problem to turn it to read-only (it already is on that mode) 
Whitch command I should do to achive his?

Thanks!
Jordi