bcache: Bypass torture test

More testing ftw! Also, now verify mode doesn't break if you read dirty
data.

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

5 files changed, 28 insertions, 8 deletions

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 97ef126b68bb..4beb55a0ff30 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -364,6 +364,7 @@ struct cached_dev {
         unsigned                readahead;
 
         unsigned                verify:1;
+        unsigned                bypass_torture_test:1;
 
         unsigned                partial_stripes_expensive:1;
         unsigned                writeback_metadata:1;
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index e99e6b8852b2..264fcfbd6290 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -189,13 +189,14 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
                 void *p1 = kmap_atomic(bv->bv_page);
                 void *p2 = page_address(check->bi_io_vec[i].bv_page);
 
-                if (memcmp(p1 + bv->bv_offset,
-                           p2 + bv->bv_offset,
-                           bv->bv_len))
-                        printk(KERN_ERR
-                               "bcache (%s): verify failed at sector %llu\n",
-                               bdevname(dc->bdev, name),
-                               (uint64_t) bio->bi_sector);
+                cache_set_err_on(memcmp(p1 + bv->bv_offset,
+                                        p2 + bv->bv_offset,
+                                        bv->bv_len),
+                                 dc->disk.c,
+                                 "verify failed at dev %s sector %llu",
+                                 bdevname(dc->bdev, name),
+                                 (uint64_t) bio->bi_sector);
+
                 kunmap_atomic(p1);
         }
 
diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h
index 7914ba0ff316..2ede60e31874 100644
--- a/drivers/md/bcache/debug.h
+++ b/drivers/md/bcache/debug.h
@@ -16,6 +16,7 @@ void bch_btree_iter_next_check(struct btree_iter *);
 #define EBUG_ON(cond)                   BUG_ON(cond)
 #define expensive_debug_checks(c)       ((c)->expensive_debug_checks)
 #define key_merging_disabled(c)         ((c)->key_merging_disabled)
+#define bypass_torture_test(d)          ((d)->bypass_torture_test)
 
 #else /* DEBUG */
 
@@ -28,6 +29,7 @@ static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
 #define EBUG_ON(cond)                   do { if (cond); } while (0)
 #define expensive_debug_checks(c)       0
 #define key_merging_disabled(c)         0
+#define bypass_torture_test(d)          0
 
 #endif
 
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 9f5a1386f77a..fbcc851ed5a5 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -528,6 +528,13 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
                 goto skip;
         }
 
+        if (bypass_torture_test(dc)) {
+                if ((get_random_int() & 3) == 3)
+                        goto skip;
+                else
+                        goto rescale;
+        }
+
         if (!congested && !dc->sequential_cutoff)
                 goto rescale;
 
@@ -601,6 +608,7 @@ struct search {
         unsigned                recoverable:1;
         unsigned                unaligned_bvec:1;
         unsigned                write:1;
+        unsigned                read_dirty_data:1;
 
         unsigned long           start_time;
 
@@ -669,6 +677,9 @@ static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k)
 
         PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO;
 
+        if (KEY_DIRTY(k))
+                s->read_dirty_data = true;
+
         n = bch_bio_split(bio, min_t(uint64_t, INT_MAX,
                                      KEY_OFFSET(k) - bio->bi_sector),
                           GFP_NOIO, s->d->bio_split);
@@ -894,7 +905,8 @@ static void cached_dev_read_done(struct closure *cl)
                 s->cache_miss = NULL;
         }
 
-        if (verify(dc, &s->bio.bio) && s->recoverable && !s->unaligned_bvec)
+        if (verify(dc, &s->bio.bio) && s->recoverable &&
+            !s->unaligned_bvec && !s->read_dirty_data)
                 bch_data_verify(dc, s->orig_bio);
 
         bio_complete(s);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 194d43782ea4..80d4c2bee18a 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -99,6 +99,7 @@ rw_attribute(errors);
 rw_attribute(io_error_limit);
 rw_attribute(io_error_halflife);
 rw_attribute(verify);
+rw_attribute(bypass_torture_test);
 rw_attribute(key_merging_disabled);
 rw_attribute(gc_always_rewrite);
 rw_attribute(expensive_debug_checks);
@@ -123,6 +124,7 @@ SHOW(__bch_cached_dev)
 
         sysfs_printf(data_csum,         "%i", dc->disk.data_csum);
         var_printf(verify,              "%i");
+        var_printf(bypass_torture_test, "%i");
         var_printf(writeback_metadata,  "%i");
         var_printf(writeback_running,   "%i");
         var_print(writeback_delay);
@@ -191,6 +193,7 @@ STORE(__cached_dev)
 
         sysfs_strtoul(data_csum,        dc->disk.data_csum);
         d_strtoul(verify);
+        d_strtoul(bypass_torture_test);
         d_strtoul(writeback_metadata);
         d_strtoul(writeback_running);
         d_strtoul(writeback_delay);
@@ -323,6 +326,7 @@ static struct attribute *bch_cached_dev_files[] = {
         &sysfs_readahead,
 #ifdef CONFIG_BCACHE_DEBUG
         &sysfs_verify,
+        &sysfs_bypass_torture_test,
 #endif
         NULL
 };