bcache: Debug code improvements

Couple changes:
 * Consolidate bch_check_keys() and bch_check_key_order(), and move the
   checks that only check_key_order() could do to bch_btree_iter_next().

 * Get rid of CONFIG_BCACHE_EDEBUG - now, all that code is compiled in
   when CONFIG_BCACHE_DEBUG is enabled, and there's now a sysfs file to
   flip on the EDEBUG checks at runtime.

 * Dropped an old not terribly useful check in rw_unlock(), and
   refactored/improved a some of the other debug code.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

1 files changed, 57 insertions, 79 deletions

diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index d9ccb3169aa2..e99e6b8852b2 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -76,29 +76,17 @@ int bch_bkey_to_text(char *buf, size_t size, const struct bkey *k)
         return out - buf;
 }
 
-int bch_btree_to_text(char *buf, size_t size, const struct btree *b)
-{
-        return scnprintf(buf, size, "%zu level %i/%i",
-                         PTR_BUCKET_NR(b->c, &b->key, 0),
-                         b->level, b->c->root ? b->c->root->level : -1);
-}
-
-#if defined(CONFIG_BCACHE_DEBUG) || defined(CONFIG_BCACHE_EDEBUG)
-
-static bool skipped_backwards(struct btree *b, struct bkey *k)
-{
-        return bkey_cmp(k, (!b->level)
-                        ? &START_KEY(bkey_next(k))
-                        : bkey_next(k)) > 0;
-}
+#ifdef CONFIG_BCACHE_DEBUG
 
 static void dump_bset(struct btree *b, struct bset *i)
 {
-        struct bkey *k;
+        struct bkey *k, *next;
         unsigned j;
         char buf[80];
 
-        for (k = i->start; k < end(i); k = bkey_next(k)) {
+        for (k = i->start; k < end(i); k = next) {
+                next = bkey_next(k);
+
                 bch_bkey_to_text(buf, sizeof(buf), k);
                 printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
                        (uint64_t *) k - i->d, i->keys, buf);
@@ -114,15 +102,21 @@ static void dump_bset(struct btree *b, struct bset *i)
 
                 printk(" %s\n", bch_ptr_status(b->c, k));
 
-                if (bkey_next(k) < end(i) &&
-                    skipped_backwards(b, k))
+                if (next < end(i) &&
+                    bkey_cmp(k, !b->level ? &START_KEY(next) : next) > 0)
                         printk(KERN_ERR "Key skipped backwards\n");
         }
 }
 
-#endif
+static void bch_dump_bucket(struct btree *b)
+{
+        unsigned i;
 
-#ifdef CONFIG_BCACHE_DEBUG
+        console_lock();
+        for (i = 0; i <= b->nsets; i++)
+                dump_bset(b, b->sets[i].data);
+        console_unlock();
+}
 
 void bch_btree_verify(struct btree *b, struct bset *new)
 {
@@ -211,11 +205,7 @@ out_put:
         bio_put(check);
 }
 
-#endif
-
-#ifdef CONFIG_BCACHE_EDEBUG
-
-unsigned bch_count_data(struct btree *b)
+int __bch_count_data(struct btree *b)
 {
         unsigned ret = 0;
         struct btree_iter iter;
@@ -227,72 +217,60 @@ unsigned bch_count_data(struct btree *b)
         return ret;
 }
 
-static void vdump_bucket_and_panic(struct btree *b, const char *fmt,
-                                   va_list args)
-{
-        unsigned i;
-        char buf[80];
-
-        console_lock();
-
-        for (i = 0; i <= b->nsets; i++)
-                dump_bset(b, b->sets[i].data);
-
-        vprintk(fmt, args);
-
-        console_unlock();
-
-        bch_btree_to_text(buf, sizeof(buf), b);
-        panic("at %s\n", buf);
-}
-
-void bch_check_key_order_msg(struct btree *b, struct bset *i,
-                             const char *fmt, ...)
-{
-        struct bkey *k;
-
-        if (!i->keys)
-                return;
-
-        for (k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
-                if (skipped_backwards(b, k)) {
-                        va_list args;
-                        va_start(args, fmt);
-
-                        vdump_bucket_and_panic(b, fmt, args);
-                        va_end(args);
-                }
-}
-
-void bch_check_keys(struct btree *b, const char *fmt, ...)
+void __bch_check_keys(struct btree *b, const char *fmt, ...)
 {
         va_list args;
         struct bkey *k, *p = NULL;
         struct btree_iter iter;
-
-        if (b->level)
-                return;
+        const char *err;
 
         for_each_key(b, k, &iter) {
-                if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) {
-                        printk(KERN_ERR "Keys out of order:\n");
-                        goto bug;
-                }
-
-                if (bch_ptr_invalid(b, k))
-                        continue;
-
-                if (p && bkey_cmp(p, &START_KEY(k)) > 0) {
-                        printk(KERN_ERR "Overlapping keys:\n");
-                        goto bug;
+                if (!b->level) {
+                        err = "Keys out of order";
+                        if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
+                                goto bug;
+
+                        if (bch_ptr_invalid(b, k))
+                                continue;
+
+                        err =  "Overlapping keys";
+                        if (p && bkey_cmp(p, &START_KEY(k)) > 0)
+                                goto bug;
+                } else {
+                        if (bch_ptr_bad(b, k))
+                                continue;
+
+                        err = "Duplicate keys";
+                        if (p && !bkey_cmp(p, k))
+                                goto bug;
                 }
                 p = k;
         }
+
+        err = "Key larger than btree node key";
+        if (p && bkey_cmp(p, &b->key) > 0)
+                goto bug;
+
         return;
 bug:
+        bch_dump_bucket(b);
+
         va_start(args, fmt);
-        vdump_bucket_and_panic(b, fmt, args);
+        vprintk(fmt, args);
         va_end(args);
+
+        panic("bcache error: %s:\n", err);
+}
+
+void bch_btree_iter_next_check(struct btree_iter *iter)
+{
+        struct bkey *k = iter->data->k, *next = bkey_next(k);
+
+        if (next < iter->data->end &&
+            bkey_cmp(k, iter->b->level ? next : &START_KEY(next)) > 0) {
+                bch_dump_bucket(iter->b);
+                panic("Key skipped backwards\n");
+        }
 }
 
 #endif