illumos gate

The zfsdev_ioctl() implementation is assuming the 32-bit version of zfs_cmd structure has exactly the same layout as 64-bit version, unfortunately those layouts has become different likely since large dnode patch, resulting with zfs send not working.

The tail output from 64-bit (kernel) kmdb:

> ::print -hta struct zfs_cmd

    ff8 zinject_record_t zc_inject_record {
        ff8 uint64_t zi_objset 
        1000 uint64_t zi_object 
        1008 uint64_t zi_start 
        1010 uint64_t zi_end 
        1018 uint64_t zi_guid 
        1020 uint32_t zi_level 
        1024 uint32_t zi_error 
        1028 uint64_t zi_type 
        1030 uint32_t zi_freq 
        1034 uint32_t zi_failfast 
        1038 char [256] zi_func 
        1138 uint32_t zi_iotype 
        113c int32_t zi_duration 
        1140 uint64_t zi_timer 
        1148 uint64_t zi_nlanes 
        1150 uint32_t zi_cmd 
        1154 uint32_t zi_pad 
        1158 uint32_t zi_dvas 
        115c uint32_t <<HOLE>> 
    }
    1160 uint32_t zc_defer_destroy 
    1164 uint32_t zc_flags 
    1168 uint64_t zc_action_handle 
    1170 int zc_cleanup_fd 
    1174 uint8_t zc_simple 
    1175 uint8_t [3] zc_pad3 
    1178 boolean_t zc_resumable 
    117c uint32_t zc_pad4 
    1180 uint64_t zc_sendobj 
    1188 uint64_t zc_fromobj 
    1190 uint64_t zc_createtxg 
    1198 zfs_stat_t zc_stat {         
        1198 uint64_t zs_gen 
        11a0 uint64_t zs_mode 
        11a8 uint64_t zs_links 
        11b0 uint64_t [2] zs_ctime 
    }
}
> 

And the same output from crashed zfs command (32-bit layout):

    ff8 zinject_record_t zc_inject_record {
        ff8 uint64_t zi_objset 
        1000 uint64_t zi_object 
        1008 uint64_t zi_start 
        1010 uint64_t zi_end 
        1018 uint64_t zi_guid 
        1020 uint32_t zi_level 
        1024 uint32_t zi_error 
        1028 uint64_t zi_type 
        1030 uint32_t zi_freq 
        1034 uint32_t zi_failfast 
        1038 char [256] zi_func 
        1138 uint32_t zi_iotype 
        113c int32_t zi_duration 
        1140 uint64_t zi_timer 
        1148 uint64_t zi_nlanes 
        1150 uint32_t zi_cmd 
        1154 uint32_t zi_pad 
        1158 uint32_t zi_dvas 
    }
    115c uint32_t zc_defer_destroy 
    1160 uint32_t zc_flags 
    1164 uint64_t zc_action_handle 
    116c int zc_cleanup_fd 
    1170 uint8_t zc_simple 
    1171 unsigned <<HOLE>> :24 
    1174 boolean_t zc_resumable 
    1178 uint8_t [3] zc_pad 
    117b uint8_t <<HOLE>> 
    117c uint64_t zc_sendobj 
    1184 uint64_t zc_fromobj 
    118c uint64_t zc_createtxg 
    1194 zfs_stat_t zc_stat {
        1194 uint64_t zs_gen 
        119c uint64_t zs_mode 
        11a4 uint64_t zs_links        
        11ac uint64_t [2] zs_ctime 
    }
}
> 

We will need to remove padding from zinject_record_t, and fix the sequence after field zc_simple in zfs_cmd. Note that yes, we are out of sync with ZoL here, and yes, we will need to keep the layout of this structure in mind and adjust if needed.