Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754843AbaKXTeT (ORCPT ); Mon, 24 Nov 2014 14:34:19 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:54931 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754652AbaKXTeP (ORCPT ); Mon, 24 Nov 2014 14:34:15 -0500 Date: Mon, 24 Nov 2014 11:34:12 -0800 From: Greg KH To: Josh Triplett Cc: Pieter Smith , Richard Weinberger , "Michael S. Tsirkin" , Bertrand Jacquin , Oleg Nesterov , "J. Bruce Fields" , Eric Dumazet , =?utf-8?B?6JSh5q2j6b6Z?= , Jeff Layton , Tom Herbert , Alexei Starovoitov , Miklos Szeredi , Peter Foley , Hugh Dickins , Xiao Guangrong , Geert Uytterhoeven , Mel Gorman , Matt Turner , "Paul E. McKenney" , Alexander Duyck , "open list:FUSE: FILESYSTEM..." , "Luis R. Rodriguez" , Catalina Mocanu , Fabian Frederick , Thomas Graf , Paul Durrant , Alexander Viro , Jan Beulich , Willem de Bruijn , Iulia Manda , "open list:ABI/API" , open list , Daniel Borkmann , "Eric W. Biederman" , "open list:NETWORKING [GENERAL]" , linux-fsdevel , Andrew Morton , "David S. Miller" Subject: Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice Message-ID: <20141124193412.GB31618@kroah.com> References: <1416752468-1626-1-git-send-email-pieter@boesman.nl> <1416752468-1626-5-git-send-email-pieter@boesman.nl> <20141123232302.GA12456@thin> <20141124094931.GA1055@smipidev> <20141124160510.GA2446@jtriplet-mobl1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141124160510.GA2446@jtriplet-mobl1> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 24, 2014 at 08:05:10AM -0800, Josh Triplett wrote: > On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote: > > On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote: > > > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote: > > > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith wrote: > > > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This > > > > > struct is exported by fs/splice. The goal of the larger patch set is to > > > > > completely compile out fs/splice, so uses of the exported struct need to be > > > > > compiled out along with fs/splice. > > > > > > > > > > This patch therefore compiles out splice support in fs/fuse when > > > > > CONFIG_SYSCALL_SPLICE is undefined. > > > > > > > > > > Signed-off-by: Pieter Smith > > > > > --- > > > > > fs/fuse/dev.c | 4 ++-- > > > > > include/linux/fs.h | 6 ++++++ > > > > > 2 files changed, 8 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c > > > > > index ca88731..f8f92a4 100644 > > > > > --- a/fs/fuse/dev.c > > > > > +++ b/fs/fuse/dev.c > > > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov, > > > > > return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs)); > > > > > } > > > > > > > > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, > > > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos, > > > > > struct pipe_inode_info *pipe, > > > > > size_t len, unsigned int flags) > > > > > { > > > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = { > > > > > .llseek = no_llseek, > > > > > .read = do_sync_read, > > > > > .aio_read = fuse_dev_read, > > > > > - .splice_read = fuse_dev_splice_read, > > > > > + .splice_read = __splice_p(fuse_dev_splice_read), > > > > > .write = do_sync_write, > > > > > .aio_write = fuse_dev_write, > > > > > .splice_write = fuse_dev_splice_write, > > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h > > > > > index a957d43..04c0975 100644 > > > > > --- a/include/linux/fs.h > > > > > +++ b/include/linux/fs.h > > > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end, > > > > > int datasync); > > > > > extern void block_sync_page(struct page *page); > > > > > > > > > > +#ifdef CONFIG_SYSCALL_SPLICE > > > > > +#define __splice_p(x) x > > > > > +#else > > > > > +#define __splice_p(x) NULL > > > > > +#endif > > > > > + > > > > > > > > This needs to go into a different patch. > > > > One logical change per patch please. :-) > > > > > > Easy enough to merge this one into the patch introducing > > > CONFIG_SYSCALL_SPLICE, then. > > > > > > - Josh Triplett > > > > The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the > > syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch > > allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to > > squash it, it would be logical to include it in PATCH 6, not 3. > > The suggestion wasn't to move the fs/fuse/dev.c bits; those should > definitely stay in this patch. The suggestion was just to move the bit > of the patch defining __splice_p from this patch to patch 3. (Note that > you need to define it before you use it, so it can't go in patch 6.) I would, again, argue that stuff like __splice_p() not be implemented at all please. It will only cause a huge proliferation of stuff like this that will not make any sense, and only cause a trivial, if any, amount of code savings. I thought you were going to not do this type of thing until you got the gcc optimizer working for function callbacks. Again, don't do this please. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/