iio: buffer: iio: core: move to the cleanup.h magic

Use the new cleanup magic for handling mutexes in IIO. This allows us to
greatly simplify some code paths.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240229-iio-use-cleanup-magic-v3-3-c3d34889ae3c@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index b581a7e805662134cd4bc8a0c80e9a44f30ee325..1d950a3e153b8a97603c883dca1773125a4eba5d 100644 (file)
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -10,6 +10,7 @@
  * - Alternative access techniques?
  */
 #include <linux/anon_inodes.h>
+#include <linux/cleanup.h>
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/device.h>
@@ -533,28 +534,26 @@ static ssize_t iio_scan_el_store(struct device *dev,
        ret = kstrtobool(buf, &state);
        if (ret < 0)
                return ret;
-       mutex_lock(&iio_dev_opaque->mlock);
-       if (iio_buffer_is_active(buffer)) {
-               ret = -EBUSY;
-               goto error_ret;
-       }
+
+       guard(mutex)(&iio_dev_opaque->mlock);
+       if (iio_buffer_is_active(buffer))
+               return -EBUSY;
+
        ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
        if (ret < 0)
-               goto error_ret;
-       if (!state && ret) {
-               ret = iio_scan_mask_clear(buffer, this_attr->address);
-               if (ret)
-                       goto error_ret;
-       } else if (state && !ret) {
-               ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
-               if (ret)
-                       goto error_ret;
-       }
+               return ret;
 
-error_ret:
-       mutex_unlock(&iio_dev_opaque->mlock);
+       if (state && ret)
+               return len;
 
-       return ret < 0 ? ret : len;
+       if (state)
+               ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
+       else
+               ret = iio_scan_mask_clear(buffer, this_attr->address);
+       if (ret)
+               return ret;
+
+       return len;
 }
 
 static ssize_t iio_scan_el_ts_show(struct device *dev,
@@ -581,16 +580,13 @@ static ssize_t iio_scan_el_ts_store(struct device *dev,
        if (ret < 0)
                return ret;
 
-       mutex_lock(&iio_dev_opaque->mlock);
-       if (iio_buffer_is_active(buffer)) {
-               ret = -EBUSY;
-               goto error_ret;
-       }
+       guard(mutex)(&iio_dev_opaque->mlock);
+       if (iio_buffer_is_active(buffer))
+               return -EBUSY;
+
        buffer->scan_timestamp = state;
-error_ret:
-       mutex_unlock(&iio_dev_opaque->mlock);
 
-       return ret ? ret : len;
+       return len;
 }
 
 static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
@@ -674,21 +670,16 @@ static ssize_t length_store(struct device *dev, struct device_attribute *attr,
        if (val == buffer->length)
                return len;
 
-       mutex_lock(&iio_dev_opaque->mlock);
-       if (iio_buffer_is_active(buffer)) {
-               ret = -EBUSY;
-       } else {
-               buffer->access->set_length(buffer, val);
-               ret = 0;
-       }
-       if (ret)
-               goto out;
+       guard(mutex)(&iio_dev_opaque->mlock);
+       if (iio_buffer_is_active(buffer))
+               return -EBUSY;
+
+       buffer->access->set_length(buffer, val);
+
        if (buffer->length && buffer->length < buffer->watermark)
                buffer->watermark = buffer->length;
-out:
-       mutex_unlock(&iio_dev_opaque->mlock);
 
-       return ret ? ret : len;
+       return len;
 }
 
 static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
@@ -1268,7 +1259,6 @@ int iio_update_buffers(struct iio_dev *indio_dev,
                       struct iio_buffer *remove_buffer)
 {
        struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
-       int ret;
 
        if (insert_buffer == remove_buffer)
                return 0;
@@ -1277,8 +1267,8 @@ int iio_update_buffers(struct iio_dev *indio_dev,
            insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT)
                return -EINVAL;
 
-       mutex_lock(&iio_dev_opaque->info_exist_lock);
-       mutex_lock(&iio_dev_opaque->mlock);
+       guard(mutex)(&iio_dev_opaque->info_exist_lock);
+       guard(mutex)(&iio_dev_opaque->mlock);
 
        if (insert_buffer && iio_buffer_is_active(insert_buffer))
                insert_buffer = NULL;
@@ -1286,23 +1276,13 @@ int iio_update_buffers(struct iio_dev *indio_dev,
        if (remove_buffer && !iio_buffer_is_active(remove_buffer))
                remove_buffer = NULL;
 
-       if (!insert_buffer && !remove_buffer) {
-               ret = 0;
-               goto out_unlock;
-       }
-
-       if (!indio_dev->info) {
-               ret = -ENODEV;
-               goto out_unlock;
-       }
-
-       ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
+       if (!insert_buffer && !remove_buffer)
+               return 0;
 
-out_unlock:
-       mutex_unlock(&iio_dev_opaque->mlock);
-       mutex_unlock(&iio_dev_opaque->info_exist_lock);
+       if (!indio_dev->info)
+               return -ENODEV;
 
-       return ret;
+       return __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
 }
 EXPORT_SYMBOL_GPL(iio_update_buffers);
 
@@ -1326,22 +1306,22 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
        if (ret < 0)
                return ret;
 
-       mutex_lock(&iio_dev_opaque->mlock);
+       guard(mutex)(&iio_dev_opaque->mlock);
 
        /* Find out if it is in the list */
        inlist = iio_buffer_is_active(buffer);
        /* Already in desired state */
        if (inlist == requested_state)
-               goto done;
+               return len;
 
        if (requested_state)
                ret = __iio_update_buffers(indio_dev, buffer, NULL);
        else
                ret = __iio_update_buffers(indio_dev, NULL, buffer);
+       if (ret)
+               return ret;
 
-done:
-       mutex_unlock(&iio_dev_opaque->mlock);
-       return (ret < 0) ? ret : len;
+       return len;
 }
 
 static ssize_t watermark_show(struct device *dev, struct device_attribute *attr,
@@ -1368,23 +1348,17 @@ static ssize_t watermark_store(struct device *dev,
        if (!val)
                return -EINVAL;
 
-       mutex_lock(&iio_dev_opaque->mlock);
+       guard(mutex)(&iio_dev_opaque->mlock);
 
-       if (val > buffer->length) {
-               ret = -EINVAL;
-               goto out;
-       }
+       if (val > buffer->length)
+               return -EINVAL;
 
-       if (iio_buffer_is_active(buffer)) {
-               ret = -EBUSY;
-               goto out;
-       }
+       if (iio_buffer_is_active(buffer))
+               return -EBUSY;
 
        buffer->watermark = val;
-out:
-       mutex_unlock(&iio_dev_opaque->mlock);
 
-       return ret ? ret : len;
+       return len;
 }
 
 static ssize_t data_available_show(struct device *dev,