btrfs-progs: ioctl/libbtrfsutil: add 3 definitions of new unprivileged ioctl

Copy and add 3 definitions of new unprivileged ioctls:

* BTRFS_IOC_GET_SUBVOL_INFO
* BTRFS_IOC_GET_SUBVOL_ROOTREF
* BTRFS_IOC_INO_LOOKUP_USER

from kernel definitions. They will be used to implement the version
of "btrfs subvolume list/show" that will not require root privileges.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 99 insertions, 0 deletions

diff --git a/ioctl.h b/ioctl.h
index 709e996f..4bf91ddb 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -320,6 +320,22 @@ struct btrfs_ioctl_ino_lookup_args {
 };
 BUILD_ASSERT(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);
 
+#define BTRFS_INO_LOOKUP_USER_PATH_MAX	(4080 - BTRFS_VOL_NAME_MAX - 1)
+struct btrfs_ioctl_ino_lookup_user_args {
+	/* in, inode number containing the subvolume of 'subvolid' */
+	__u64 dirid;
+	/* in */
+	__u64 treeid;
+	/* out, name of the subvolume of 'treeid' */
+	char name[BTRFS_VOL_NAME_MAX + 1];
+	/*
+	 * out, constructed path from the directory with which the ioctl is
+	 * called to dirid
+	 */
+	char path[BTRFS_INO_LOOKUP_USER_PATH_MAX];
+};
+BUILD_ASSERT(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);
+
 struct btrfs_ioctl_search_key {
 	/* which root are we searching.  0 is the tree of tree roots */
 	__u64 tree_id;
@@ -672,6 +688,83 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_send_args_64) == 72);
 
 #define BTRFS_IOC_SEND_64_COMPAT_DEFINED 1
 
+/*
+ * Information about a fs tree root.
+ *
+ * All items are filled by the ioctl
+ */
+struct btrfs_ioctl_get_subvol_info_args {
+	/* Id of this subvolume */
+	__u64 treeid;
+
+	/* Name of this subvolume, used to get the real name at mount point */
+	char name[BTRFS_VOL_NAME_MAX + 1];
+
+	/*
+	 * Id of the subvolume which contains this subvolume.
+	 * Zero for top-level subvolume or a deleted subvolume.
+	 */
+	__u64 parent_id;
+
+	/*
+	 * Inode number of the directory which contains this subvolume.
+	 * Zero for top-level subvolume or a deleted subvolume
+	 */
+	__u64 dirid;
+
+	/* Latest transaction id of this subvolume */
+	__u64 generation;
+
+	/* Flags of this subvolume */
+	__u64 flags;
+
+	/* UUID of this subvolume */
+	__u8 uuid[BTRFS_UUID_SIZE];
+
+	/*
+	 * UUID of the subvolume of which this subvolume is a snapshot.
+	 * All zero for a non-snapshot subvolume.
+	 */
+	__u8 parent_uuid[BTRFS_UUID_SIZE];
+
+	/*
+	 * UUID of the subvolume from which this subvolume was received.
+	 * All zero for non-received subvolume.
+	 */
+	__u8 received_uuid[BTRFS_UUID_SIZE];
+
+	/* Transaction id indicating when change/create/send/receive happened */
+	__u64 ctransid;
+	__u64 otransid;
+	__u64 stransid;
+	__u64 rtransid;
+	/* Time corresponding to c/o/s/rtransid */
+	struct btrfs_ioctl_timespec ctime;
+	struct btrfs_ioctl_timespec otime;
+	struct btrfs_ioctl_timespec stime;
+	struct btrfs_ioctl_timespec rtime;
+
+	/* Must be zero */
+	__u64 reserved[8];
+};
+
+#define BTRFS_MAX_ROOTREF_BUFFER_NUM			255
+struct btrfs_ioctl_get_subvol_rootref_args {
+	/* in/out, minimum id of rootref's treeid to be searched */
+	__u64 min_treeid;
+
+	/* out */
+	struct {
+		__u64 treeid;
+		__u64 dirid;
+	} rootref[BTRFS_MAX_ROOTREF_BUFFER_NUM];
+
+	/* out, number of found items */
+	__u8 num_items;
+	__u8 align[7];
+};
+BUILD_ASSERT(sizeof(struct btrfs_ioctl_get_subvol_rootref_args) == 4096);
+
 /* Error codes as returned by the kernel */
 enum btrfs_err_code {
 	notused,
@@ -828,6 +921,12 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
                                   struct btrfs_ioctl_feature_flags[3])
 #define BTRFS_IOC_RM_DEV_V2	_IOW(BTRFS_IOCTL_MAGIC, 58, \
 				   struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_GET_SUBVOL_INFO _IOR(BTRFS_IOCTL_MAGIC, 60, \
+				struct btrfs_ioctl_get_subvol_info_args)
+#define BTRFS_IOC_GET_SUBVOL_ROOTREF _IOWR(BTRFS_IOCTL_MAGIC, 61, \
+				struct btrfs_ioctl_get_subvol_rootref_args)
+#define BTRFS_IOC_INO_LOOKUP_USER _IOWR(BTRFS_IOCTL_MAGIC, 62, \
+				struct btrfs_ioctl_ino_lookup_user_args)
 #ifdef __cplusplus
 }
 #endif