After upgrading our server subversion to 1.6.2 on a new repo i run into this error when commiting:
svn attempt to write a readonly database
Although if i looked at the repo the commited files were there.
After hunting Google a bit, I found the problem to be with the “/svn/repopath/db/rep-cache.db” file that did not have write permissions for the user subversion uses.
After fixing permissions, committing went perfectly with no errors.
Hope it helps.