On mounted CIFS filesystem, files cannot be overwritten, even though they can be created, deleted, and appended

Issue

• On a CIFS mounted filesystem, files cannot be overwritten, even though they can be created, deleted, and appended. For example:

# touch /mnt/test
# echo overwrite > /mnt/test
-bash: /mnt/test: Input/output error
# echo append >> /mnt/test
# cat /mnt/test
append
# rm /mnt/test
rm: remove regular file `/mnt/test'? y
# ls /mnt/test
ls: /mnt/test: No such file or directory