[RFC PATCH 1/8] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock

[Hans Verkuil]

Where reasonable use mutex_lock_interruptible instead of mutex_lock.

Signed-off-by: Hans Verkuil <hverk...@xs4all.nl>
---
 drivers/media/video/v4l2-dev.c |   44 +++++++++++++++++++++++++++++----------
 1 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 0ca7978..8eb0756 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -191,8 +191,12 @@ static ssize_t v4l2_read(struct file *filp, char __user 
*buf,
 
        if (!vdev->fops->read)
                return -EINVAL;
-       if (vdev->lock)
-               mutex_lock(vdev->lock);
+       if (vdev->lock) {
+               int res = mutex_lock_interruptible(vdev->lock);
+
+               if (res)
+                       return res;
+       }
        if (video_is_registered(vdev))
                ret = vdev->fops->read(filp, buf, sz, off);
        if (vdev->lock)
@@ -208,8 +212,12 @@ static ssize_t v4l2_write(struct file *filp, const char 
__user *buf,
 
        if (!vdev->fops->write)
                return -EINVAL;
-       if (vdev->lock)
-               mutex_lock(vdev->lock);
+       if (vdev->lock) {
+               int res = mutex_lock_interruptible(vdev->lock);
+
+               if (res)
+                       return res;
+       }
        if (video_is_registered(vdev))
                ret = vdev->fops->write(filp, buf, sz, off);
        if (vdev->lock)
@@ -224,8 +232,8 @@ static unsigned int v4l2_poll(struct file *filp, struct 
poll_table_struct *poll)
 
        if (!vdev->fops->poll)
                return ret;
-       if (vdev->lock)
-               mutex_lock(vdev->lock);
+       if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+               return ret;
        if (video_is_registered(vdev))
                ret = vdev->fops->poll(filp, poll);
        if (vdev->lock)
@@ -239,8 +247,12 @@ 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) {
+                       int res = mutex_lock_interruptible(vdev->lock);
+
+                       if (res)
+                               return res;
+               }
                if (video_is_registered(vdev))
                        ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
                if (vdev->lock)
@@ -264,8 +276,12 @@ 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) {
+               int res = mutex_lock_interruptible(vdev->lock);
+
+               if (res)
+                       return res;
+       }
        if (video_is_registered(vdev))
                ret = vdev->fops->mmap(filp, vm);
        if (vdev->lock)
@@ -291,8 +307,11 @@ 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) {
+                       ret = mutex_lock_interruptible(vdev->lock);
+                       if (ret)
+                               goto err;
+               }
                if (video_is_registered(vdev))
                        ret = vdev->fops->open(filp);
                else
@@ -301,6 +320,7 @@ 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);
-- 
1.7.0.4

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