rbd: define rbd_assert()

Define rbd_assert() and use it in place of various BUG_ON() calls
now present in the code.  By default assertion checking is enabled;
we want to do this differently at some point.

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

1 files changed, 26 insertions, 9 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 7ba70c49bbdb..d84b5341bea2 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -41,6 +41,8 @@
 
 #include "rbd_types.h"
 
+#define RBD_DEBUG       /* Activate rbd_assert() calls */
+
 /*
  * The basic unit of block I/O is a sector.  It is interpreted in a
  * number of contexts in Linux (blk, bio, genhd), but the default is
@@ -232,6 +234,18 @@ static struct device rbd_root_dev = {
         .release =      rbd_root_dev_release,
 };
 
+#ifdef RBD_DEBUG
+#define rbd_assert(expr)                                                \
+                if (unlikely(!(expr))) {                                \
+                        printk(KERN_ERR "\nAssertion failure in %s() "  \
+                                                "at line %d:\n\n"       \
+                                        "\trbd_assert(%s);\n\n",        \
+                                        __func__, __LINE__, #expr);     \
+                        BUG();                                          \
+                }
+#else /* !RBD_DEBUG */
+#  define rbd_assert(expr)      ((void) 0)
+#endif /* !RBD_DEBUG */
 
 static struct device *rbd_get_dev(struct rbd_device *rbd_dev)
 {
@@ -406,7 +420,8 @@ static int parse_rbd_opts_token(char *c, void *private)
                 rbd_opts->read_only = false;
                 break;
         default:
-                BUG_ON(token);
+                rbd_assert(false);
+                break;
         }
         return 0;
 }
@@ -705,7 +720,7 @@ static u64 rbd_segment_length(struct rbd_device *rbd_dev,
 
         offset &= segment_size - 1;
 
-        BUG_ON(length > U64_MAX - offset);
+        rbd_assert(length <= U64_MAX - offset);
         if (offset + length > segment_size)
                 length = segment_size - offset;
 
@@ -842,7 +857,7 @@ static struct bio *bio_chain_clone(struct bio **old, struct bio **next,
                 total += tmp->bi_size;
         }
 
-        BUG_ON(total < len);
+        rbd_assert(total == len);
 
         *old = old_chain;
 
@@ -1101,7 +1116,7 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev,
         struct page **pages;
         int num_pages;
 
-        BUG_ON(ops == NULL);
+        rbd_assert(ops != NULL);
 
         num_pages = calc_pages_for(ofs , len);
         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
@@ -1163,7 +1178,7 @@ static int rbd_do_op(struct request *rq,
         /* we've taken care of segment sizes earlier when we
            cloned the bios. We should never have a segment
            truncated at this point */
-        BUG_ON(seg_len < len);
+        rbd_assert(seg_len == len);
 
         ret = rbd_do_request(rq, rbd_dev, snapc, snapid,
                              seg_name, seg_ofs, seg_len,
@@ -2186,7 +2201,7 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                                              : CEPH_NOSNAP;
                 snap = links != head ? list_entry(links, struct rbd_snap, node)
                                      : NULL;
-                BUG_ON(snap && snap->id == CEPH_NOSNAP);
+                rbd_assert(!snap || snap->id != CEPH_NOSNAP);
 
                 if (snap_id == CEPH_NOSNAP || (snap && snap->id > snap_id)) {
                         struct list_head *next = links->next;
@@ -2222,8 +2237,9 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                 } else {
                         /* Already have this one */
 
-                        BUG_ON(snap->size != rbd_dev->header.snap_sizes[index]);
-                        BUG_ON(strcmp(snap->name, snap_name));
+                        rbd_assert(snap->size ==
+                                        rbd_dev->header.snap_sizes[index]);
+                        rbd_assert(!strcmp(snap->name, snap_name));
 
                         /* Done with this list entry; advance */
 
@@ -2313,7 +2329,7 @@ static void rbd_id_put(struct rbd_device *rbd_dev)
         int rbd_id = rbd_dev->dev_id;
         int max_id;
 
-        BUG_ON(rbd_id < 1);
+        rbd_assert(rbd_id > 0);
 
         spin_lock(&rbd_dev_list_lock);
         list_del_init(&rbd_dev->node);
@@ -2705,6 +2721,7 @@ static ssize_t rbd_remove(struct bus_type *bus,
 
 done:
         mutex_unlock(&ctl_mutex);
+
         return ret;
 }