rbd: add warning messages for missing arguments

Tell the user (via dmesg) what was wrong with the arguments provided
via /sys/bus/rbd/add.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>

1 files changed, 16 insertions, 8 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 635b81d0ebdb..31da8c538480 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3244,8 +3244,10 @@ static int rbd_add_parse_args(const char *buf,
         /* The first four tokens are required */
 
         len = next_token(&buf);
-        if (!len)
-                return -EINVAL; /* Missing monitor address(es) */
+        if (!len) {
+                rbd_warn(NULL, "no monitor address(es) provided");
+                return -EINVAL;
+        }
         mon_addrs = buf;
         mon_addrs_size = len + 1;
         buf += len;
@@ -3254,8 +3256,10 @@ static int rbd_add_parse_args(const char *buf,
         options = dup_token(&buf, NULL);
         if (!options)
                 return -ENOMEM;
-        if (!*options)
-                goto out_err;   /* Missing options */
+        if (!*options) {
+                rbd_warn(NULL, "no options provided");
+                goto out_err;
+        }
 
         spec = rbd_spec_alloc();
         if (!spec)
@@ -3264,14 +3268,18 @@ static int rbd_add_parse_args(const char *buf,
         spec->pool_name = dup_token(&buf, NULL);
         if (!spec->pool_name)
                 goto out_mem;
-        if (!*spec->pool_name)
-                goto out_err;   /* Missing pool name */
+        if (!*spec->pool_name) {
+                rbd_warn(NULL, "no pool name provided");
+                goto out_err;
+        }
 
         spec->image_name = dup_token(&buf, NULL);
         if (!spec->image_name)
                 goto out_mem;
-        if (!*spec->image_name)
-                goto out_err;   /* Missing image name */
+        if (!*spec->image_name) {
+                rbd_warn(NULL, "no image name provided");
+                goto out_err;
+        }
 
         /*
          * Snapshot name is optional; default is to use "-"