btrfs: added helper functions to iterate backrefs
These helper functions iterate back references and call a function for each
backref. There is also a function to resolve an inode to a path in the
file system.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index ad1ea78..1857e38 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -193,6 +193,17 @@
struct btrfs_ioctl_space_info spaces[0];
};
+struct btrfs_data_container {
+ __u32 bytes_left; /* out -- bytes not needed to deliver output */
+ __u32 bytes_missing; /* out -- additional bytes needed for result */
+ __u32 elem_cnt; /* out */
+ __u32 elem_missed; /* out */
+ union {
+ char *str[0]; /* out */
+ __u64 val[0]; /* out */
+ };
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \