Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753110Ab3JSS1K (ORCPT ); Sat, 19 Oct 2013 14:27:10 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:32915 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752448Ab3JSS1I (ORCPT ); Sat, 19 Oct 2013 14:27:08 -0400 Message-ID: <5262CEF6.1040003@gmail.com> Date: Sat, 19 Oct 2013 20:27:02 +0200 From: Sylwester Nawrocki User-Agent: Mozilla/5.0 (X11; Linux i686; rv:11.0) Gecko/20120412 Thunderbird/11.0.1 MIME-Version: 1.0 To: Ricardo Ribalda CC: Kyungmin Park , Sylwester Nawrocki , Mauro Carvalho Chehab , Kukjin Kim , Pawel Osciak , Marek Szyprowski , linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] videobuf2: Add missing lock held on vb2_fop_relase References: <1382198877-27164-1-git-send-email-ricardo.ribalda@gmail.com> In-Reply-To: <1382198877-27164-1-git-send-email-ricardo.ribalda@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5199 Lines: 157 On 10/19/2013 06:07 PM, Ricardo Ribalda wrote: [...] > --- > drivers/media/platform/exynos4-is/fimc-capture.c | 2 +- > drivers/media/platform/exynos4-is/fimc-lite.c | 2 +- > drivers/media/usb/em28xx/em28xx-video.c | 2 +- > drivers/media/v4l2-core/videobuf2-core.c | 18 +++++++++++++++++- > include/media/videobuf2-core.h | 2 ++ > 5 files changed, 22 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c > index fb27ff7..c38d247c 100644 > --- a/drivers/media/platform/exynos4-is/fimc-capture.c > +++ b/drivers/media/platform/exynos4-is/fimc-capture.c > @@ -549,7 +549,7 @@ static int fimc_capture_release(struct file *file) > vc->streaming = false; > } > > - ret = vb2_fop_release(file); > + ret = __vb2_fop_release(file, true); > > if (close) { > clear_bit(ST_CAPT_BUSY,&fimc->state); > diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c > index e5798f7..021d804 100644 > --- a/drivers/media/platform/exynos4-is/fimc-lite.c > +++ b/drivers/media/platform/exynos4-is/fimc-lite.c > @@ -546,7 +546,7 @@ static int fimc_lite_release(struct file *file) > mutex_unlock(&entity->parent->graph_mutex); > } > > - vb2_fop_release(file); > + __vb2_fop_release(file, true); > pm_runtime_put(&fimc->pdev->dev); > clear_bit(ST_FLITE_SUSPENDED,&fimc->state); > > diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c > index 9d10334..6a5c147 100644 > --- a/drivers/media/usb/em28xx/em28xx-video.c > +++ b/drivers/media/usb/em28xx/em28xx-video.c > @@ -1664,7 +1664,7 @@ static int em28xx_v4l2_close(struct file *filp) > em28xx_videodbg("users=%d\n", dev->users); > > mutex_lock(&dev->lock); > - vb2_fop_release(filp); > + __vb2_fop_release(filp, false); I believe no modifications are needed for this driver. > if (dev->users == 1) { > /* the device is already disconnect, > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 594c75e..ce309a8 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -2619,16 +2619,32 @@ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) > } > EXPORT_SYMBOL_GPL(vb2_fop_mmap); > > -int vb2_fop_release(struct file *file) > +int __vb2_fop_release(struct file *file, bool lock_is_held) > { > struct video_device *vdev = video_devdata(file); > + struct mutex *lock; > > if (file->private_data == vdev->queue->owner) { > + if (lock_is_held) > + lock = NULL; > + else > + lock = vdev->queue->lock ? > + vdev->queue->lock : vdev->lock; > + if (lock) > + mutex_lock(lock); > vb2_queue_release(vdev->queue); > vdev->queue->owner = NULL; > + if (lock) > + mutex_unlock(lock); > } > return v4l2_fh_release(file); > } > +EXPORT_SYMBOL_GPL(__vb2_fop_release); > + > +int vb2_fop_release(struct file *file) > +{ > + return __vb2_fop_release(file, false); > +} > EXPORT_SYMBOL_GPL(vb2_fop_release); It might be better to make it something like: static int _vb2_fop_release(struct file *file, bool locked) { struct video_device *vdev = video_devdata(file); struct mutex *lock; if (file->private_data == vdev->queue->owner) { lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; if (lock && !locked) mutex_lock(lock); vb2_queue_release(vdev->queue); vdev->queue->owner = NULL; if (lock && !locked) mutex_unlock(lock); } return v4l2_fh_release(file); } int vb2_fop_release(struct file *file) { return _vb2_fop_release(file, false); } EXPORT_SYMBOL_GPL(vb2_fop_release); /* * This function should be used instead of vb2_fop_release() * if the caller already holds the video queue mutex. */ int __vb2_fop_release(struct file *file) { return _vb2_fop_release(file, true); } EXPORT_SYMBOL_GPL(__vb2_fop_release); since __vb2_fop_release(file, false); is basically useless, it is same as vb2_fop_release(file); > ssize_t vb2_fop_write(struct file *file, char __user *buf, > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index 6781258..cd1e4d5 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -491,6 +491,8 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, > > int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); > int vb2_fop_release(struct file *file); > +/* must be used if the lock is held. */ Let's put any comments at the function body, not here. > +int __vb2_fop_release(struct file *file, bool lock_is_held); int __vb2_fop_release(struct file *file); > ssize_t vb2_fop_write(struct file *file, char __user *buf, > size_t count, loff_t *ppos); > ssize_t vb2_fop_read(struct file *file, char __user *buf, Thanks, Sylwester -- 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/