+/*
+ * Size of structure depends on pointer width, was not caught in the early
+ * days. Kernel handles pointer width differences transparently.
+ */
+BUILD_ASSERT(sizeof(__u64 *) == 8
+ ? sizeof(struct btrfs_ioctl_send_args) == 72
+ : (sizeof(void *) == 4
+ ? sizeof(struct btrfs_ioctl_send_args) == 68
+ : 0));
+
+/*
+ * Different pointer width leads to structure size change. Kernel should accept
+ * both ioctl values (derived from the structures) for backward compatibility.
+ * Size of this structure is same on 32bit and 64bit though.
+ *
+ * NOTE: do not use in your code, this is for testing only
+ */
+struct btrfs_ioctl_send_args_64 {
+ __s64 send_fd; /* in */
+ __u64 clone_sources_count; /* in */
+ union {
+ __u64 __user *clone_sources; /* in */
+ __u64 __clone_sources_alignment;
+ };
+ __u64 parent_root; /* in */
+ __u64 flags; /* in */
+ __u64 reserved[4]; /* in */
+} __attribute__((packed));
+BUILD_ASSERT(sizeof(struct btrfs_ioctl_send_args_64) == 72);
+
+#define BTRFS_IOC_SEND_64_COMPAT_DEFINED 1
+
+/* Error codes as returned by the kernel */
+enum btrfs_err_code {
+ notused,
+ BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
+ BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
+ BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
+ BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
+ BTRFS_ERROR_DEV_TGT_REPLACE,
+ BTRFS_ERROR_DEV_MISSING_NOT_FOUND,
+ BTRFS_ERROR_DEV_ONLY_WRITABLE,
+ BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS
+};
+
+/* An error code to error string mapping for the kernel
+* error codes
+*/
+static inline char *btrfs_err_str(enum btrfs_err_code err_code)
+{
+ switch (err_code) {
+ case BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET:
+ return "unable to go below two devices on raid1";
+ case BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET:
+ return "unable to go below four devices on raid10";
+ case BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET:
+ return "unable to go below two devices on raid5";
+ case BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET:
+ return "unable to go below three devices on raid6";
+ case BTRFS_ERROR_DEV_TGT_REPLACE:
+ return "unable to remove the dev_replace target dev";
+ case BTRFS_ERROR_DEV_MISSING_NOT_FOUND:
+ return "no missing devices found to remove";
+ case BTRFS_ERROR_DEV_ONLY_WRITABLE:
+ return "unable to remove the only writeable device";
+ case BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS:
+ return "add/delete/balance/replace/resize operation "
+ "in progress";
+ default:
+ return NULL;
+ }
+}