From mboxrd@z Thu Jan 1 00:00:00 1970 From: chrubis-AlSwsSmVLrQ@public.gmane.org Subject: Re: [PATCH] statfs.2: Update + Note for pipe() fds Date: Tue, 10 Jun 2014 23:29:40 +0200 Message-ID: <20140610212940.GA22111@rei.Home> References: <20140610160416.GA20354@rei.Home> <53976A4D.1010501@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <53976A4D.1010501-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" Cc: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org Hi! > > * Update MAGIC constants, most of them are taken from > > /usr/include/linux/magic.h, some were found by grepping Linux source. > > > > * Add note about fstatfs(2) broken on fd from pipe(2) between > > 2.6.38 and 3.2 > > I moved that patch piece to a (new) BUGS section. > > Looking at the following: > > $ git describe --contains ff0c7d15f9787b7e8c601533c01529 > v2.6.38-rc1~60^2~30 > $ git describe --contains d70ef97baf048412c395bb5d65791d > v3.2-rc1~108^2~56 > > The breakage was from 2.6.38 to 3.1, right? (3.2 fixed things.) > I reworded a little. Ah, right. Sorry for the off by one mistake. > And I just want to check. Was it really ff0c7d15f9787b7e8c601533c01529 > that caused the breakage? At a quick glance, that patch looks > unrelated, but perhaps something very subtle is going on... Yep, it took me a while to notice. If you pass NULL as super_operations to mount_pseudo() function, which was the case before the patch, default structure super_operations (with contains only simple_statfs) is used (have a look at mount_pseudo() in fs/libfs.c). This patch added pipefs_ops without the statfs callback and passed it instead of the NULL. -- Cyril Hrubis chrubis-AlSwsSmVLrQ@public.gmane.org -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html