On Tue, 2007-09-18 at 11:19 -0400, J. Bruce Fields wrote: > Maybe this should be documented, e.g. in fcntl(2). I'm not sure exactly > what we'd say--we probably don't want to commit to the current behavior. > Maybe something like "behavior is undefined when setting or clearing > mandatory locking on a file while it is locked".
The behaviour is pretty much undefined if you set/clear mandatory locking on the file while some application has it open. It is hard to see how you can avoid that unless you exclude simultaneous chmod, read(), write(), and fcntl(SETLK) operations. Note also that strictly speaking, we're not even compliant with the System V behaviour on read() and write(). See: http://www.unix.org.ua/orelly/networking_2ndEd/nfs/ch11_01.htm and http://docs.sun.com/app/docs/doc/801-6736/6i13fom0a?l=en&a=view&q=mandatory+lock According to these docs, we should be wrapping each and every read() and write() syscall with a mandatory lock. The fact that we're not, and yet still not seeing any complaints just goes to show how few people are actually using and relying on this... Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
