fsck: input/output error

ls -la

-??? ? ? ? ? ? fstab

ls fstab
ls: cannot access fstab: Input/output error

sudo fsck -y
fsck from util-linux 2.20.1
fsck: WARNING: couldn’t open /etc/fstab: Input/output error

Any suggestions how to fix this without reapplying the image?

(If you wonder, what happended: I tried to auto-mount a disk that cannot be mounted via UI, messed something, Volumio crashed on every boot, therefore no ssh, and then I modified the file from my Mac using EXTFS, which in fact made the Raspberry boot again, however, with messed file system for that one file)

Hm, can you see/read the /etc/fstab with your Mac?
Compare the content with these original entries:

[code]cat /etc/fstab

/etc/fstab: static file system information.

#/dev/mmcblk0p3 / ext4 noatime,discard,data=writeback,journal_async_commit,nouser_xattr,barrier=0,errors=remount-ro 0 1
/dev/mmcblk0p3 / ext4 noatime,nouser_xattr,errors=remount-ro 0 1
/dev/mmcblk0p1 /boot vfat utf8 0 0
Ramdisk /run/shm tmpfs defaults,size=256M,noexec,nodev,nosuid 0 0
Perhaps a typo?

It is even worse, I can not ls the file and of course I can not edit it any more. See command line quotes in my first post. I already picked the correct lines out of the source files, however, the system does not let me touch the file any more.
And no, I can’t read it on Mac either.