Hi Jeff, On 21 January 2015 at 18:47, Jeff Layton <jlayton@xxxxxxxxxxxxxxx> wrote: > On Wed, 21 Jan 2015 18:44:41 +0100 > "Michael Kerrisk (man-pages)" <mtk.manpages@xxxxxxxxx> wrote: > >> Hi Jeff, >> >> I was recently checking some details of the man page for OFD locks, >> and realized that one paragraph is somewhat misleading: >> >> Open file description locks always conflict with traditional >> record locks, even when they are acquired by the same process on >> the same file descriptor. >> >> This doesn't capture the full story, as far as I can tell. In >> particular if we have two processes that take locks on the same region >> of a file as follows: >> >> F_OFD_SETLK F_RDLCK >> and >> F_SETLK F_RDLCK >> >> then those pair of locks are compatible. I assume that's expected >> behavior, right? I've drafted the patch below for the man page. Seem >> okay? >> >> Cheers, >> >> Michael >> >> diff --git a/man2/fcntl.2 b/man2/fcntl.2 >> index 59f22ce..03c2ae8 100644 >> --- a/man2/fcntl.2 >> +++ b/man2/fcntl.2 >> @@ -495,7 +495,10 @@ and are only automatically released on the last close >> of the open file description, >> instead of being released on any close of the file. >> .PP >> -Open file description locks always conflict with traditional record locks, >> +Conflicting lock combinations >> +(i.e., a read lock and a write lock or two write locks) >> +where one lock is an open file description lock and the other >> +is a traditional record lock conflict >> even when they are acquired by the same process on the same file descriptor. >> >> Open file description locks placed via the same open file description >> >> > > Yes, that is expected behavior and your patch looks good to me. > > Acked-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx> Thanks for the fast response!! It's a shame not to see you around the mailing lists no more (at least not the ones I frequent). Best regards, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
