[PATCH 2/8] btrfs-progs: sub list: factor out main part of btrfs_list_subvols

[Misono Tomohiro <misono.tomohiro@xxxxxxxxxxxxxx>]

No functional changes.
This is a preparation work for reworking "subvolume list".

Signed-off-by: Misono Tomohiro <misono.tomohiro@xxxxxxxxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
---
 cmds-subvolume.c | 50 +++++++++++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 84a03fd8..40cc2687 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -1128,22 +1128,15 @@ out:
 	return subvols;
 }
 
-static struct subvol_list *btrfs_list_subvols(int fd,
-					      struct btrfs_list_filter_set_v2 *filter_set)
+static void get_subvols_info(struct subvol_list **subvols,
+			     struct btrfs_list_filter_set_v2 *filter_set,
+			     int fd,
+			     size_t *capacity)
 {
-	struct subvol_list *subvols;
-	size_t capacity = 0;
 	struct btrfs_util_subvolume_iterator *iter;
 	enum btrfs_util_error err;
 	int ret = -1;
 
-	subvols = malloc(sizeof(*subvols));
-	if (!subvols) {
-		error("out of memory");
-		return NULL;
-	}
-	subvols->num = 0;
-
 	err = btrfs_util_create_subvolume_iterator_fd(fd,
 						      BTRFS_FS_TREE_OBJECTID, 0,
 						      &iter);
@@ -1171,11 +1164,11 @@ static struct subvol_list *btrfs_list_subvols(int fd,
 			continue;
 		}
 
-		if (subvols->num >= capacity) {
+		if ((*subvols)->num >= *capacity) {
 			struct subvol_list *new_subvols;
-			size_t new_capacity = max_t(size_t, 1, capacity * 2);
+			size_t new_capacity = max_t(size_t, 1, *capacity * 2);
 
-			new_subvols = realloc(subvols,
+			new_subvols = realloc(*subvols,
 					      sizeof(*new_subvols) +
 					      new_capacity *
 					      sizeof(new_subvols->subvols[0]));
@@ -1184,12 +1177,12 @@ static struct subvol_list *btrfs_list_subvols(int fd,
 				goto out;
 			}
 
-			subvols = new_subvols;
-			capacity = new_capacity;
+			*subvols = new_subvols;
+			*capacity = new_capacity;
 		}
 
-		subvols->subvols[subvols->num] = subvol;
-		subvols->num++;
+		(*subvols)->subvols[(*subvols)->num] = subvol;
+		(*subvols)->num++;
 	}
 
 	ret = 0;
@@ -1197,9 +1190,26 @@ out:
 	if (iter)
 		btrfs_util_destroy_subvolume_iterator(iter);
 	if (ret) {
-		free_subvol_list(subvols);
-		subvols = NULL;
+		free_subvol_list(*subvols);
+		*subvols = NULL;
+	}
+}
+
+static struct subvol_list *btrfs_list_subvols(int fd,
+					      struct btrfs_list_filter_set_v2 *filter_set)
+{
+	struct subvol_list *subvols;
+	size_t capacity = 0;
+
+	subvols = malloc(sizeof(*subvols));
+	if (!subvols) {
+		error("out of memory");
+		return NULL;
 	}
+	subvols->num = 0;
+
+	get_subvols_info(&subvols, filter_set, fd, &capacity);
+
 	return subvols;
 }
 
-- 
2.19.1