bcachefs: Replace bare EEXIST with private error codes

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

fs/bcachefs/alloc_background.c

@@ -1643,7 +1643,7 @@ static int discard_in_flight_add(struct bch_fs *c, struct bpos bucket)
 	mutex_lock(&c->discard_buckets_in_flight_lock);
 	darray_for_each(c->discard_buckets_in_flight, i)
 		if (bkey_eq(*i, bucket)) {
-			ret = -EEXIST;
+			ret = -BCH_ERR_EEXIST_discard_in_flight_add;
 			goto out;
 		}
 

fs/bcachefs/errcode.h

@@ -116,6 +116,9 @@
 	x(ENOENT,			ENOENT_dev_idx_not_found)		\
 	x(ENOTEMPTY,			ENOTEMPTY_dir_not_empty)		\
 	x(ENOTEMPTY,			ENOTEMPTY_subvol_not_empty)		\
+	x(EEXIST,			EEXIST_str_hash_set)			\
+	x(EEXIST,			EEXIST_discard_in_flight_add)		\
+	x(EEXIST,			EEXIST_subvolume_create)		\
 	x(0,				open_buckets_empty)			\
 	x(0,				freelist_empty)				\
 	x(BCH_ERR_freelist_empty,	no_buckets_found)			\

fs/bcachefs/fs-ioctl.c

@@ -373,7 +373,7 @@ static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 	}
 
 	if (dst_dentry->d_inode) {
-		error = -EEXIST;
+		error = -BCH_ERR_EEXIST_subvolume_create;
 		goto err3;
 	}
 

fs/bcachefs/str_hash.h

@@ -300,7 +300,7 @@ int bch2_hash_set_in_snapshot(struct btree_trans *trans,
 	if (!found && (flags & STR_HASH_must_replace)) {
 		ret = -BCH_ERR_ENOENT_str_hash_set_must_replace;
 	} else if (found && (flags & STR_HASH_must_create)) {
-		ret = -EEXIST;
+		ret = -BCH_ERR_EEXIST_str_hash_set;
 	} else {
 		if (!found && slot.path)
 			swap(iter, slot);

fs/bcachefs/super.c

@@ -931,12 +931,13 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 	if (ret)
 		goto err;
 
-	for (i = 0; i < c->sb.nr_devices; i++)
-		if (bch2_member_exists(c->disk_sb.sb, i) &&
-		    bch2_dev_alloc(c, i)) {
-			ret = -EEXIST;
+	for (i = 0; i < c->sb.nr_devices; i++) {
+		if (!bch2_member_exists(c->disk_sb.sb, i))
+			continue;
+		ret = bch2_dev_alloc(c, i);
+		if (ret)
 			goto err;
-		}
+	}
 
 	bch2_journal_entry_res_resize(&c->journal,
 			&c->btree_root_journal_res,