diff options
Diffstat (limited to 'utils-lib.c')
-rw-r--r-- | utils-lib.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/utils-lib.c b/utils-lib.c index 79ef35e3..044f93fc 100644 --- a/utils-lib.c +++ b/utils-lib.c @@ -2,9 +2,13 @@ #include <unistd.h> #include <stdlib.h> #include <limits.h> +#include <sys/ioctl.h> +#include <ioctl.h> #if BTRFS_FLAT_INCLUDES +#include "ctree.h" #else +#include <btrfs/ctree.h> #endif /* BTRFS_FLAT_INCLUDES */ /* @@ -38,3 +42,29 @@ u64 arg_strtou64(const char *str) } return value; } + +/* + * For a given: + * - file or directory return the containing tree root id + * - subvolume return its own tree id + * - BTRFS_EMPTY_SUBVOL_DIR_OBJECTID (directory with ino == 2) the result is + * undefined and function returns -1 + */ +int lookup_path_rootid(int fd, u64 *rootid) +{ + struct btrfs_ioctl_ino_lookup_args args; + int ret; + + memset(&args, 0, sizeof(args)); + args.treeid = 0; + args.objectid = BTRFS_FIRST_FREE_OBJECTID; + + ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args); + if (ret < 0) + return -errno; + + *rootid = args.treeid; + + return 0; +} + |