Btrfs-progs: add function btrfs_get_subvol to get root_info of a subvol

We need a function which can get the root_info of a given
subvol. This is in preparation to add support for the show
sub-cli.

Signed-off-by: Anand Jain <anand.jain@oracle.com>

diff --git a/btrfs-list.c b/btrfs-list.c
index 3bd305b..247711d 100644 (file)
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1468,6 +1468,44 @@ int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
        return 0;
 }
 
+int btrfs_get_subvol(int fd, struct root_info *the_ri)
+{
+       int ret = -1;
+       struct root_lookup rl;
+       struct rb_node *rbn;
+       struct root_info *ri;
+       u64 root_id = btrfs_list_get_path_rootid(fd);
+
+       if (btrfs_list_subvols(fd, &rl))
+               return 1;
+
+       rbn = rb_first(&rl.root);
+       while(rbn) {
+               ri = rb_entry(rbn, struct root_info, rb_node);
+               resolve_root(&rl, ri, root_id);
+               if (!comp_entry_with_rootid(the_ri, ri, 0)) {
+                       memcpy(the_ri, ri, offsetof(struct root_info, path));
+                       if (ri->path)
+                               the_ri->path = strdup(ri->path);
+                       else
+                               the_ri->path = NULL;
+                       if (ri->name)
+                               the_ri->name = strdup(ri->name);
+                       else
+                               the_ri->name = NULL;
+                       if (ri->full_path)
+                               the_ri->full_path = strdup(ri->full_path);
+                       else
+                               the_ri->name = NULL;
+                       ret = 0;
+                       break;
+               }
+               rbn = rb_next(rbn);
+       }
+       __free_all_subvolumn(&rl);
+       return ret;
+}
+
 static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
                            struct btrfs_file_extent_item *item,
                            u64 found_gen, u64 *cache_dirid,

diff --git a/btrfs-list.h b/btrfs-list.h
index f945734..7c0d4c5 100644 (file)
--- a/btrfs-list.h
+++ b/btrfs-list.h
@@ -152,3 +152,4 @@ int btrfs_list_find_updated_files(int fd, u64 root_id, u64 oldest_gen);
 int btrfs_list_get_default_subvolume(int fd, u64 *default_id);
 char *btrfs_list_path_for_root(int fd, u64 root);
 u64 btrfs_list_get_path_rootid(int fd);
+int btrfs_get_subvol(int fd, struct root_info *the_ri);