Comment 120 for bug 1021375

I know I'm not running the latest LTS, but 16.04, yet I tried Etienne's advice (because it seems to make perfect sense), but fsck wasn't allowed to fix a FAT-mismatch:

   sudo fsck.vfat /dev/sdf1
   fsck.fat 3.0.28 (2015-05-16)
   FATs differ but appear to be intact. Use which FAT ?
   1) Use first FAT
   2) Use second FAT
   ? 1
   Perform changes ? (y/n) y
   /dev/sdf1: 25 files, 445911/487648 clusters
   Writing 1950600 bytes at 2243584 failed: Operation not permitted

Seems like the readonly even applies to "sudo fsck". Permissions of the block device are:

   brw-rw---- 1 root disk 8, 81 Sep 28 23:04 /dev/sdf1

As it seems that this issue is still open, I hope that maybe someone might find this information useful for debugging.

Thanks for any hints!