Regards, Jerry Schwartz Global Information Incorporated 195 Farmington Ave. Farmington, CT 06032
860.674.8796 / FAX: 860.674.8341 E-mail: je...@gii.co.jp Web site: www.the-infoshop.com >-----Original Message----- >From: Joerg Bruehe [mailto:joerg.bru...@oracle.com] >Sent: Wednesday, January 19, 2011 2:56 PM >To: Jerry Schwartz >Cc: mysql@lists.mysql.com >Subject: Re: Can't read dir of '.' (errno: 13) > >Hi ! > > >Jerry Schwartz wrote: >>> -----Original Message----- >>> From: Joerg Bruehe [mailto:joerg.bru...@oracle.com] >>> Sent: Wednesday, January 19, 2011 10:43 AM >>> To: mysql@lists.mysql.com >>> Cc: Jerry Schwartz >>> Subject: Re: Can't read dir of '.' (errno: 13) >>> >>> Hi! >>> >>> >>> Jerry Schwartz wrote: >>>>> -[[...]] >>>>> >>>> [JS] I have a related question: how can MySQL authenticate a user if file >>>> system permissions won't let it read any databases? >>> To me, your question sounds like you forgot the difference between >>> server and client: >>> >> [JS] I don't think so, but perhaps I misunderstood the source of the error >> message. >> >> mysql> show databases ; >> ERROR 1018 (HY000): Can't read dir of '.' (errno: 13) >> >> Are you saying that the mysql CLI needs to read some directory ('.', in >> this >> case) in order to send mysqld a simple query like SHOW DATABASES? I would >hope >> it doesn't need a temporary file for that. > >No, I didn't say that. > >You say that "the mysql CLI ... send(s) mysqld a simple query ...", and >that is correct: the client ("mysql") sends the command "show databases" >to the server ("mysqld"). >To process this, the server has to check the file(s) and directory(ies) >used to store the database contents, and one of those actions is to read >the current directory. > >> >> Who is issuing the errno 13, the client or the daemon? > >AIUI, it is the server, encountering a permission problem. >So the server encounters a problem, and it reports this back to the >client who will then output the message. > > >Your question that triggered my original reply was: > how can MySQL authenticate a user if file system permissions > won't let it read any databases? > >My original reply tried to make it obvious that the user (who is to be >authenticated) is just a database concept, so this (maybe non-existing) >user's (possibly missing) permissions in the operating system to read >any OS object (file, directory) do not matter at all when the MySQL >server does the authentication. >It is the server (process) that needs the permissions to read (and >write) database directories and files. > >Of course, if these permissions are missing, then the server cannot >operate (and so also cannot authenticate a user), but that is a question >of server setup and not of database user privileges. > [JS] Sorry, that still doesn't make sense to em. To authenticate the user, mysqld needs to read the mysql database. That is also where the databases are listed (in `mysql`.`db`). If the daemon can read `mysql`.`user`, why can't it read `mysql`.`db`? It's a MyISAM database, so everything is in the same file. What am I missing? Does SHOW DATABASES do something other than pull the database names out of `mysql`.`db`? > >HTH, >Jörg > >-- >Joerg Bruehe, MySQL Build Team, joerg.bru...@oracle.com >ORACLE Deutschland B.V. & Co. KG, Komturstrasse 18a, D-12099 Berlin >Geschaeftsfuehrer: Juergen Kunz, Marcel v.d. Molen, Alexander v.d. Ven >Amtsgericht Muenchen: HRA 95603 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
