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>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 7ba70c49bbdbf1321b8e2372db1426aebbf216bf..d84b5341bea25c95d3822308c6b92443ecddae32 100644 (file)
--- 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;
 }