From 2877842de8cbf6272b0a851cb12587b7dd8c2afb Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 26 Nov 2010 06:43:51 -0300 Subject: [PATCH] [media] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock Where reasonable use mutex_lock_interruptible instead of mutex_lock. Also fix the poll, read and write error codes when called with an unregistered device (e.g. after a USB device was disconnected). Poll must return POLLERR|POLLHUP and read/write must return -ENODEV. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/v4l2-dev.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 03f7f4670e9b..bfd392e2436d 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -186,12 +186,12 @@ static ssize_t v4l2_read(struct file *filp, char __user *buf, size_t sz, loff_t *off) { struct video_device *vdev = video_devdata(filp); - int ret = -EIO; + int ret = -ENODEV; if (!vdev->fops->read) return -EINVAL; - if (vdev->lock) - mutex_lock(vdev->lock); + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) + return -ERESTARTSYS; if (video_is_registered(vdev)) ret = vdev->fops->read(filp, buf, sz, off); if (vdev->lock) @@ -203,12 +203,12 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf, size_t sz, loff_t *off) { struct video_device *vdev = video_devdata(filp); - int ret = -EIO; + int ret = -ENODEV; if (!vdev->fops->write) return -EINVAL; - if (vdev->lock) - mutex_lock(vdev->lock); + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) + return -ERESTARTSYS; if (video_is_registered(vdev)) ret = vdev->fops->write(filp, buf, sz, off); if (vdev->lock) @@ -219,10 +219,10 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf, static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) { struct video_device *vdev = video_devdata(filp); - int ret = DEFAULT_POLLMASK; + int ret = POLLERR | POLLHUP; if (!vdev->fops->poll) - return ret; + return DEFAULT_POLLMASK; if (vdev->lock) mutex_lock(vdev->lock); if (video_is_registered(vdev)) @@ -238,8 +238,8 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) int ret = -ENODEV; if (vdev->fops->unlocked_ioctl) { - if (vdev->lock) - mutex_lock(vdev->lock); + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) + return -ERESTARTSYS; if (video_is_registered(vdev)) ret = vdev->fops->unlocked_ioctl(filp, cmd, arg); if (vdev->lock) @@ -265,8 +265,8 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) if (!vdev->fops->mmap) return ret; - if (vdev->lock) - mutex_lock(vdev->lock); + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) + return -ERESTARTSYS; if (video_is_registered(vdev)) ret = vdev->fops->mmap(filp, vm); if (vdev->lock) @@ -292,8 +292,10 @@ static int v4l2_open(struct inode *inode, struct file *filp) video_get(vdev); mutex_unlock(&videodev_lock); if (vdev->fops->open) { - if (vdev->lock) - mutex_lock(vdev->lock); + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) { + ret = -ERESTARTSYS; + goto err; + } if (video_is_registered(vdev)) ret = vdev->fops->open(filp); else @@ -302,6 +304,7 @@ static int v4l2_open(struct inode *inode, struct file *filp) mutex_unlock(vdev->lock); } +err: /* decrease the refcount in case of an error */ if (ret) video_put(vdev);