bcache: Add a real GC_MARK_RECLAIMABLE

This means the garbage collection code can better check for data and metadata
pointers to the same buckets.

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

diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index a3e1427945f24c0a21263cc97d9d22e0e2f195b2..5ba4eaea57f4532fa91e738a762e4cef2031331e 100644 (file)
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -155,7 +155,8 @@ add:
 
 static bool can_invalidate_bucket(struct cache *ca, struct bucket *b)
 {
-       return GC_MARK(b) == GC_MARK_RECLAIMABLE &&
+       return (!GC_MARK(b) ||
+               GC_MARK(b) == GC_MARK_RECLAIMABLE) &&
                !atomic_read(&b->pin) &&
                can_inc_bucket_gen(b);
 }
@@ -475,7 +476,7 @@ void bch_bucket_free(struct cache_set *c, struct bkey *k)
        for (i = 0; i < KEY_PTRS(k); i++) {
                struct bucket *b = PTR_BUCKET(c, k, i);
 
-               SET_GC_MARK(b, GC_MARK_RECLAIMABLE);
+               SET_GC_MARK(b, 0);
                SET_GC_SECTORS_USED(b, 0);
                bch_bucket_add_unused(PTR_CACHE(c, k, i), b);
        }

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 6d814f463d9ef6f6450274696d522dd3ff2b77d1..014236e411d84ab6b5d9898aff5139ab242fa6a0 100644 (file)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -207,9 +207,9 @@ struct bucket {
  */
 
 BITMASK(GC_MARK,        struct bucket, gc_mark, 0, 2);
-#define GC_MARK_RECLAIMABLE    0
-#define GC_MARK_DIRTY          1
-#define GC_MARK_METADATA       2
+#define GC_MARK_RECLAIMABLE    1
+#define GC_MARK_DIRTY          2
+#define GC_MARK_METADATA       3
 #define GC_SECTORS_USED_SIZE   13
 #define MAX_GC_SECTORS_USED    (~(~0ULL << GC_SECTORS_USED_SIZE))
 BITMASK(GC_SECTORS_USED, struct bucket, gc_mark, 2, GC_SECTORS_USED_SIZE);

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index ea5a59e2d74081f9c6483d9358604e0721db226c..1672db348c8bc0e96ba306ddd5ca66e492265dd3 100644 (file)
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1160,6 +1160,8 @@ static uint8_t __bch_btree_mark_key(struct cache_set *c, int level,
                        SET_GC_MARK(g, GC_MARK_METADATA);
                else if (KEY_DIRTY(k))
                        SET_GC_MARK(g, GC_MARK_DIRTY);
+               else if (!GC_MARK(g))
+                       SET_GC_MARK(g, GC_MARK_RECLAIMABLE);
 
                /* guard against overflow */
                SET_GC_SECTORS_USED(g, min_t(unsigned,
@@ -1559,7 +1561,7 @@ static void btree_gc_start(struct cache_set *c)
                for_each_bucket(b, ca) {
                        b->gc_gen = b->gen;
                        if (!atomic_read(&b->pin)) {
-                               SET_GC_MARK(b, GC_MARK_RECLAIMABLE);
+                               SET_GC_MARK(b, 0);
                                SET_GC_SECTORS_USED(b, 0);
                        }
                }
@@ -1622,12 +1624,16 @@ size_t bch_btree_gc_finish(struct cache_set *c)
                        b->last_gc      = b->gc_gen;
                        c->need_gc      = max(c->need_gc, bucket_gc_gen(b));
 
-                       if (!atomic_read(&b->pin) &&
-                           GC_MARK(b) == GC_MARK_RECLAIMABLE) {
+                       if (atomic_read(&b->pin))
+                               continue;
+
+                       BUG_ON(!GC_MARK(b) && GC_SECTORS_USED(b));
+
+                       if (!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE)
                                available++;
-                               if (!GC_SECTORS_USED(b))
-                                       bch_bucket_add_unused(ca, b);
-                       }
+
+                       if (!GC_MARK(b))
+                               bch_bucket_add_unused(ca, b);
                }
        }
 

diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c
index 416d1a3e028e03a34a9d03e31b9e6fa583c9b357..82d5e3288a6cd59ec01de8b119478df18291a8f1 100644 (file)
--- a/drivers/md/bcache/extents.c
+++ b/drivers/md/bcache/extents.c
@@ -499,9 +499,9 @@ static bool bch_extent_bad_expensive(struct btree *b, const struct bkey *k,
 
        if (mutex_trylock(&b->c->bucket_lock)) {
                if (b->c->gc_mark_valid &&
-                   ((GC_MARK(g) != GC_MARK_DIRTY &&
-                     KEY_DIRTY(k)) ||
-                    GC_MARK(g) == GC_MARK_METADATA))
+                   (!GC_MARK(g) ||
+                    GC_MARK(g) == GC_MARK_METADATA ||
+                    (GC_MARK(g) != GC_MARK_DIRTY && KEY_DIRTY(k))))
                        goto err;
 
                if (g->prio == BTREE_PRIO)