From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752575Ab0C0Kks (ORCPT ); Sat, 27 Mar 2010 06:40:48 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:42050 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752036Ab0C0Kkq (ORCPT ); Sat, 27 Mar 2010 06:40:46 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sat, 27 Mar 2010 11:40:31 +0100 (CET) From: Stefan Richter Subject: [PATCH RFC] DVB: add dvb_generic_nonseekable_open, dvb_generic_unlocked_ioctl, use in firedtv To: linux-media@vger.kernel.org cc: linux-kernel@vger.kernel.org, Mauro Carvalho Chehab , Arnd Bergmann , Henrik Kurelid In-Reply-To: <4BAD4795.2040700@s5r6.in-berlin.de> Message-ID: References: <201003242240.54907.arnd@arndb.de> <201003251406.10177.arnd@arndb.de> <201003251438.59062.arnd@arndb.de> <4BAD4795.2040700@s5r6.in-berlin.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to remove Big Kernel Lock usages from the DVB subsystem, we need to - provide .llseek file operations that do not grab the BKL (unlike fs/read_write.c::default_llseek) or mark files as not seekable, - provide .unlocked_ioctl file operations. Add two dvb_generic_ file operations for file interfaces which are not seekable and, respectively, do not require the BKL in their ioctl handlers. Use them in one driver of which I am sure of that these are applicable. (Affected code paths were not runtime-tested since I don't have a CAM.) Notes: - In order to maximize code reuse and minimize API churn, I pass a dummy NULL struct inode * through dvb_usercopy() to dvbdev->kernel_ioctl(). Very ugly; it may be better to convert everything from .ioctl to .unlocked_ioctl in one go and remove the inode pointer argument everywhere. - I suspect that actually all dvb_generic_open() users really want nonseekable_open --- then we should simply change dvb_generic_open() instead of adding dvb_generic_nonseekable_open() --- but I haven't checked other users of dvb_generic_open whether they require .llssek mehods other than fs/read_write.c::no_llseek. Signed-off-by: Stefan Richter --- This patch is motivated by Arnd's "bkl removal: make unlocked_ioctl mandatory" http://git.kernel.org/?p=linux/kernel/git/arnd/playground.git;a=blobdiff;f=drivers/media/dvb/firewire/firedtv-ci.c;h=7ab89035c101240a860d6c72bf8541a0fdf3aed9;hp=853e04b7cb361d45257f80dcafdcf121cd340c63;hb=05e7753338045e9ee3950b2da032c5e5774efa90;hpb=03165e1d096afb4b1d9cfccdad66eed038121cec "BKL removal: mark remaining users as 'depends on BKL'" http://git.kernel.org/?p=linux/kernel/git/arnd/playground.git;a=blobdiff;f=drivers/media/dvb/firewire/Kconfig;h=ba8938e26414c8c82c41677f87c1361ed8fcebd0;hp=4afa29256df110d3383b6b469762cefbb46436b6;hb=abb83d8fe5f8dcc8fca09bd9117429f73e1417e0;hpb=33c014b118f45516113d4b6823e40ea6f834dc6a drivers/media/dvb/dvb-core/dvbdev.c | 20 ++++++++++++++++++++ drivers/media/dvb/dvb-core/dvbdev.h | 11 +++++++---- drivers/media/dvb/firewire/firedtv-ci.c | 4 ++-- 3 files changed, 29 insertions(+), 6 deletions(-) Index: b/drivers/media/dvb/dvb-core/dvbdev.c =================================================================== --- a/drivers/media/dvb/dvb-core/dvbdev.c +++ b/drivers/media/dvb/dvb-core/dvbdev.c @@ -135,6 +135,18 @@ int dvb_generic_open(struct inode *inode EXPORT_SYMBOL(dvb_generic_open); +int dvb_generic_nonseekable_open(struct inode *inode, struct file *file) +{ + int retval = dvb_generic_open(inode, file); + + if (retval == 0) + retval = nonseekable_open(inode, file); + + return retval; +} +EXPORT_SYMBOL(dvb_generic_nonseekable_open); + + int dvb_generic_release(struct inode *inode, struct file *file) { struct dvb_device *dvbdev = file->private_data; @@ -170,6 +182,14 @@ int dvb_generic_ioctl(struct inode *inod EXPORT_SYMBOL(dvb_generic_ioctl); +long dvb_generic_unlocked_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + return dvb_generic_ioctl(NULL, file, cmd, arg); +} +EXPORT_SYMBOL(dvb_generic_unlocked_ioctl); + + static int dvbdev_get_free_id (struct dvb_adapter *adap, int type) { u32 id = 0; Index: b/drivers/media/dvb/dvb-core/dvbdev.h =================================================================== --- a/drivers/media/dvb/dvb-core/dvbdev.h +++ b/drivers/media/dvb/dvb-core/dvbdev.h @@ -136,10 +136,13 @@ extern int dvb_register_device (struct d extern void dvb_unregister_device (struct dvb_device *dvbdev); -extern int dvb_generic_open (struct inode *inode, struct file *file); -extern int dvb_generic_release (struct inode *inode, struct file *file); -extern int dvb_generic_ioctl (struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg); +extern int dvb_generic_open(struct inode *inode, struct file *file); +extern int dvb_generic_nonseekable_open(struct inode *inode, struct file *file); +extern int dvb_generic_release(struct inode *inode, struct file *file); +extern int dvb_generic_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg); +extern long dvb_generic_unlocked_ioctl(struct file *file, + unsigned int cmd, unsigned long arg); /* we don't mess with video_usercopy() any more, we simply define out own dvb_usercopy(), which will hopefully become Index: b/drivers/media/dvb/firewire/firedtv-ci.c =================================================================== --- a/drivers/media/dvb/firewire/firedtv-ci.c +++ b/drivers/media/dvb/firewire/firedtv-ci.c @@ -217,8 +217,8 @@ static unsigned int fdtv_ca_io_poll(stru static const struct file_operations fdtv_ca_fops = { .owner = THIS_MODULE, - .ioctl = dvb_generic_ioctl, - .open = dvb_generic_open, + .unlocked_ioctl = dvb_generic_unlocked_ioctl, + .open = dvb_generic_nonseekable_open, .release = dvb_generic_release, .poll = fdtv_ca_io_poll, }; -- Stefan Richter -=====-==-=- --== ==-== http://arcgraph.de/sr/