rbd: have __rbd_add_snap_dev() return a pointer

It's not obvious whether the snapshot pointer whose address is
provided to __rbd_add_snap_dev() will be assigned by that function.
Change it to return the snapshot, or a pointer-coded errno in the
event of a failure.

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

1 files changed, 22 insertions, 15 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 30eb01e300a4..aba0d71a0345 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2029,15 +2029,21 @@ static int rbd_register_snap_dev(struct rbd_snap *snap,
         return ret;
 }
 
-static int __rbd_add_snap_dev(struct rbd_device *rbd_dev,
-                              int i, const char *name,
-                              struct rbd_snap **snapp)
+static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev,
+                                              int i, const char *name)
 {
+        struct rbd_snap *snap;
         int ret;
-        struct rbd_snap *snap = kzalloc(sizeof(*snap), GFP_KERNEL);
+
+        snap = kzalloc(sizeof (*snap), GFP_KERNEL);
         if (!snap)
-                return -ENOMEM;
+                return ERR_PTR(-ENOMEM);
+
+        ret = -ENOMEM;
         snap->name = kstrdup(name, GFP_KERNEL);
+        if (!snap->name)
+                goto err;
+
         snap->size = rbd_dev->header.snap_sizes[i];
         snap->id = rbd_dev->header.snapc->snaps[i];
         if (device_is_registered(&rbd_dev->dev)) {
@@ -2045,12 +2051,14 @@ static int __rbd_add_snap_dev(struct rbd_device *rbd_dev,
                 if (ret < 0)
                         goto err;
         }
-        *snapp = snap;
-        return 0;
+
+        return snap;
+
 err:
         kfree(snap->name);
         kfree(snap);
-        return ret;
+
+        return ERR_PTR(ret);
 }
 
 /*
@@ -2083,7 +2091,6 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
         const char *name, *first_name;
         int i = rbd_dev->header.total_snaps;
         struct rbd_snap *snap, *old_snap = NULL;
-        int ret;
         struct list_head *p, *n;
 
         first_name = rbd_dev->header.snap_names;
@@ -2126,9 +2133,9 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                         if (cur_id >= old_snap->id)
                                 break;
                         /* a new snapshot */
-                        ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap);
-                        if (ret < 0)
-                                return ret;
+                        snap = __rbd_add_snap_dev(rbd_dev, i - 1, name);
+                        if (IS_ERR(snap))
+                                return PTR_ERR(snap);
 
                         /* note that we add it backward so using n and not p */
                         list_add(&snap->node, n);
@@ -2142,9 +2149,9 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                         WARN_ON(1);
                         return -EINVAL;
                 }
-                ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap);
-                if (ret < 0)
-                        return ret;
+                snap = __rbd_add_snap_dev(rbd_dev, i - 1, name);
+                if (IS_ERR(snap))
+                        return PTR_ERR(snap);
                 list_add(&snap->node, &rbd_dev->snaps);
         }