bcachefs: Change allocations for ec stripes to blocking

XXX

It's not guaranteed that these allocations will ever succeed, we can
currently get stuck - especially if devices are different sizes.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

3 files changed, 38 insertions, 31 deletions

diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index 7a92e3d53254..0c5c69d643f6 100644
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -458,16 +458,18 @@ bch2_bucket_alloc_set(struct bch_fs *c,
  * it's to a device we don't want:
  */
 
-static void bucket_alloc_from_stripe(struct bch_fs *c,
-				     struct open_buckets *ptrs,
-				     struct write_point *wp,
-				     struct bch_devs_mask *devs_may_alloc,
-				     u16 target,
-				     unsigned erasure_code,
-				     unsigned nr_replicas,
-				     unsigned *nr_effective,
-				     bool *have_cache,
-				     unsigned flags)
+static enum bucket_alloc_ret
+bucket_alloc_from_stripe(struct bch_fs *c,
+			 struct open_buckets *ptrs,
+			 struct write_point *wp,
+			 struct bch_devs_mask *devs_may_alloc,
+			 u16 target,
+			 unsigned erasure_code,
+			 unsigned nr_replicas,
+			 unsigned *nr_effective,
+			 bool *have_cache,
+			 unsigned flags,
+			 struct closure *cl)
 {
 	struct dev_alloc_list devs_sorted;
 	struct ec_stripe_head *h;
@@ -476,17 +478,19 @@ static void bucket_alloc_from_stripe(struct bch_fs *c,
 	unsigned i, ec_idx;
 
 	if (!erasure_code)
-		return;
+		return 0;
 
 	if (nr_replicas < 2)
-		return;
+		return 0;
 
 	if (ec_open_bucket(c, ptrs))
-		return;
+		return 0;
 
-	h = bch2_ec_stripe_head_get(c, target, 0, nr_replicas - 1);
+	h = bch2_ec_stripe_head_get(c, target, 0, nr_replicas - 1, cl);
+	if (IS_ERR(h))
+		return -PTR_ERR(h);
 	if (!h)
-		return;
+		return 0;
 
 	devs_sorted = bch2_dev_alloc_list(c, &wp->stripe, devs_may_alloc);
 
@@ -508,6 +512,7 @@ got_bucket:
 	atomic_inc(&h->s->pin);
 out_put_head:
 	bch2_ec_stripe_head_put(c, h);
+	return 0;
 }
 
 /* Sector allocator */
@@ -585,10 +590,13 @@ open_bucket_add_buckets(struct bch_fs *c,
 		}
 
 		if (!ec_open_bucket(c, ptrs)) {
-			bucket_alloc_from_stripe(c, ptrs, wp, &devs,
+			ret = bucket_alloc_from_stripe(c, ptrs, wp, &devs,
 						 target, erasure_code,
 						 nr_replicas, nr_effective,
-						 have_cache, flags);
+						 have_cache, flags, _cl);
+			if (ret == FREELIST_EMPTY ||
+			    ret == OPEN_BUCKETS_EMPTY)
+				return ret;
 			if (*nr_effective >= nr_replicas)
 				return 0;
 		}
diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c
index beb91d33a992..903b81744c8f 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -1229,10 +1229,9 @@ found:
 	return h;
 }
 
-/*
- * XXX: use a higher watermark for allocating open buckets here:
- */
-static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h)
+static enum bucket_alloc_ret
+new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h,
+			 struct closure *cl)
 {
 	struct bch_devs_mask devs;
 	struct open_bucket *ob;
@@ -1240,7 +1239,7 @@ static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h)
 		min_t(unsigned, h->nr_active_devs,
 		      BCH_BKEY_PTRS_MAX) - h->redundancy;
 	bool have_cache = true;
-	int ret = 0;
+	enum bucket_alloc_ret ret = ALLOC_SUCCESS;
 
 	devs = h->devs;
 
@@ -1271,7 +1270,7 @@ static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h)
 					    &have_cache,
 					    RESERVE_NONE,
 					    0,
-					    NULL);
+					    cl);
 		if (ret)
 			goto err;
 	}
@@ -1287,7 +1286,7 @@ static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h)
 					    &have_cache,
 					    RESERVE_NONE,
 					    0,
-					    NULL);
+					    cl);
 		if (ret)
 			goto err;
 	}
@@ -1353,7 +1352,8 @@ static int get_stripe_key(struct bch_fs *c, u64 idx, struct ec_stripe_buf *strip
 struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *c,
 					       unsigned target,
 					       unsigned algo,
-					       unsigned redundancy)
+					       unsigned redundancy,
+					       struct closure *cl)
 {
 	struct ec_stripe_head *h;
 	struct open_bucket *ob;
@@ -1422,14 +1422,13 @@ struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *c,
 				bch2_ec_stripe_head_put(c, h);
 				h = NULL;
 				goto out;
-
 			}
-
 		}
 
-		if (new_stripe_alloc_buckets(c, h)) {
+		ret = new_stripe_alloc_buckets(c, h, cl);
+		if (ret) {
 			bch2_ec_stripe_head_put(c, h);
-			h = NULL;
+			h = ERR_PTR(-ret);
 			goto out;
 		}
 
diff --git a/fs/bcachefs/ec.h b/fs/bcachefs/ec.h
index 1d4aad50db4d..3f1999bae6d4 100644
--- a/fs/bcachefs/ec.h
+++ b/fs/bcachefs/ec.h
@@ -146,8 +146,8 @@ void bch2_ec_bucket_cancel(struct bch_fs *, struct open_bucket *);
 int bch2_ec_stripe_new_alloc(struct bch_fs *, struct ec_stripe_head *);
 
 void bch2_ec_stripe_head_put(struct bch_fs *, struct ec_stripe_head *);
-struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *, unsigned,
-					       unsigned, unsigned);
+struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *,
+			unsigned, unsigned, unsigned, struct closure *);
 
 void bch2_stripes_heap_update(struct bch_fs *, struct stripe *, size_t);
 void bch2_stripes_heap_del(struct bch_fs *, struct stripe *, size_t);