rbd: create rbd_refresh_helper()

Create a simple helper that handles the common case of calling
__rbd_refresh_header() while holding the ctl_mutex.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index de981ac..9917943 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -240,7 +240,7 @@ static void rbd_put_dev(struct rbd_device *rbd_dev)
        put_device(&rbd_dev->dev);
 }
 
-static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver);
+static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver);
 
 static int rbd_open(struct block_device *bdev, fmode_t mode)
 {
@@ -1225,9 +1225,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
        dout("rbd_watch_cb %s notify_id=%llu opcode=%u\n",
                rbd_dev->header_name, (unsigned long long) notify_id,
                (unsigned int) opcode);
-       mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-       rc = __rbd_refresh_header(rbd_dev, &hver);
-       mutex_unlock(&ctl_mutex);
+       rc = rbd_refresh_header(rbd_dev, &hver);
        if (rc)
                pr_warning(RBD_DRV_NAME "%d got notification but failed to "
                           " update snaps: %d\n", rbd_dev->major, rc);
@@ -1751,6 +1749,17 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
        return ret;
 }
 
+static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
+{
+       int ret;
+
+       mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+       ret = __rbd_refresh_header(rbd_dev, hver);
+       mutex_unlock(&ctl_mutex);
+
+       return ret;
+}
+
 static int rbd_init_disk(struct rbd_device *rbd_dev)
 {
        struct gendisk *disk;
@@ -1904,9 +1913,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
        struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
        int ret;
 
-       mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-       ret = __rbd_refresh_header(rbd_dev, NULL);
-       mutex_unlock(&ctl_mutex);
+       ret = rbd_refresh_header(rbd_dev, NULL);
 
        return ret < 0 ? ret : size;
 }
@@ -2196,9 +2203,7 @@ static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
        do {
                ret = rbd_req_sync_watch(rbd_dev);
                if (ret == -ERANGE) {
-                       mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-                       rc = __rbd_refresh_header(rbd_dev, NULL);
-                       mutex_unlock(&ctl_mutex);
+                       rc = rbd_refresh_header(rbd_dev, NULL);
                        if (rc < 0)
                                return rc;
                }