bcachefs: Add some printks for error paths

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

fs/bcachefs/btree_gc.c

@@ -701,8 +701,10 @@ static int bch2_gc_start(struct bch_fs *c,
 
 	c->usage_gc = __alloc_percpu_gfp(fs_usage_u64s(c) * sizeof(u64),
 					 sizeof(u64), GFP_KERNEL);
-	if (!c->usage_gc)
+	if (!c->usage_gc) {
+		bch_err(c, "error allocating c->usage_gc");
 		return -ENOMEM;
+	}
 
 	for_each_member_device(ca, c, i) {
 		BUG_ON(ca->buckets[1]);
@@ -713,19 +715,23 @@ static int bch2_gc_start(struct bch_fs *c,
 				GFP_KERNEL|__GFP_ZERO);
 		if (!ca->buckets[1]) {
 			percpu_ref_put(&ca->ref);
+			bch_err(c, "error allocating ca->buckets[gc]");
 			return -ENOMEM;
 		}
 
 		ca->usage[1] = alloc_percpu(struct bch_dev_usage);
 		if (!ca->usage[1]) {
+			bch_err(c, "error allocating ca->usage[gc]");
 			percpu_ref_put(&ca->ref);
 			return -ENOMEM;
 		}
 	}
 
 	ret = bch2_ec_mem_alloc(c, true);
-	if (ret)
+	if (ret) {
+		bch_err(c, "error allocating ec gc mem");
 		return ret;
+	}
 
 	percpu_down_write(&c->mark_lock);
 

fs/bcachefs/replicas.c

@@ -304,8 +304,10 @@ static int replicas_table_update(struct bch_fs *c,
 	if (!(new_base = kzalloc(bytes, GFP_NOIO)) ||
 	    !(new_scratch  = kmalloc(scratch_bytes, GFP_NOIO)) ||
 	    (c->usage_gc &&
-	     !(new_gc = __alloc_percpu_gfp(bytes, sizeof(u64), GFP_NOIO))))
+	     !(new_gc = __alloc_percpu_gfp(bytes, sizeof(u64), GFP_NOIO)))) {
+		bch_err(c, "error updating replicas table: memory allocation failure");
 		goto err;
+	}
 
 	for (i = 0; i < ARRAY_SIZE(new_usage); i++)
 		if (c->usage[i])
@@ -365,7 +367,7 @@ static int bch2_mark_replicas_slowpath(struct bch_fs *c,
 				struct bch_replicas_entry *new_entry)
 {
 	struct bch_replicas_cpu new_r, new_gc;
-	int ret = -ENOMEM;
+	int ret = 0;
 
 	verify_replicas_entry(new_entry);
 
@@ -412,14 +414,16 @@ static int bch2_mark_replicas_slowpath(struct bch_fs *c,
 		swap(new_gc, c->replicas_gc);
 	percpu_up_write(&c->mark_lock);
 out:
-	ret = 0;
-err:
 	mutex_unlock(&c->sb_lock);
 
 	kfree(new_r.entries);
 	kfree(new_gc.entries);
 
 	return ret;
+err:
+	bch_err(c, "error adding replicas entry: memory allocation failure");
+	ret = -ENOMEM;
+	goto out;
 }
 
 int bch2_mark_replicas(struct bch_fs *c,
@@ -564,6 +568,7 @@ int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
 					 GFP_NOIO);
 	if (!c->replicas_gc.entries) {
 		mutex_unlock(&c->sb_lock);
+		bch_err(c, "error allocating c->replicas_gc");
 		return -ENOMEM;
 	}
 
@@ -589,8 +594,10 @@ int bch2_replicas_gc2(struct bch_fs *c)
 	nr		= READ_ONCE(c->replicas.nr);
 	new.entry_size	= READ_ONCE(c->replicas.entry_size);
 	new.entries	= kcalloc(nr, new.entry_size, GFP_KERNEL);
-	if (!new.entries)
+	if (!new.entries) {
+		bch_err(c, "error allocating c->replicas_gc");
 		return -ENOMEM;
+	}
 
 	mutex_lock(&c->sb_lock);
 	percpu_down_write(&c->mark_lock);