rbd: make rbd spec names pointer to const

Make the names and image id in an rbd_spec be pointers to constant
data.  This required the use of a local variable to hold the
snapshot name in rbd_add_parse_args() to avoid a warning.

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

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index c34f8716d1d2..e728e11096b4 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -138,13 +138,13 @@ struct rbd_image_header {
  */
 struct rbd_spec {
         u64             pool_id;
-        char            *pool_name;
+        const char      *pool_name;
 
-        char            *image_id;
-        char            *image_name;
+        const char      *image_id;
+        const char      *image_name;
 
         u64             snap_id;
-        char            *snap_name;
+        const char      *snap_name;
 
         struct kref     kref;
 };
@@ -4375,6 +4375,7 @@ static int rbd_add_parse_args(const char *buf,
         size_t len;
         char *options;
         const char *mon_addrs;
+        char *snap_name;
         size_t mon_addrs_size;
         struct rbd_spec *spec = NULL;
         struct rbd_options *rbd_opts = NULL;
@@ -4433,10 +4434,11 @@ static int rbd_add_parse_args(const char *buf,
                 ret = -ENAMETOOLONG;
                 goto out_err;
         }
-        spec->snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
-        if (!spec->snap_name)
+        snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
+        if (!snap_name)
                 goto out_mem;
-        *(spec->snap_name + len) = '\0';
+        *(snap_name + len) = '\0';
+        spec->snap_name = snap_name;
 
         /* Initialize all rbd options to the defaults */