• Jacob Keller's avatar
    devlink: report 0 after hitting end in region read · d5b90e99
    Jacob Keller authored
    commit fdd41ec2 ("devlink: Return right error code in case of errors
    for region read") modified the region read code to report errors
    properly in unexpected cases.
    
    In the case where the start_offset and ret_offset match, it unilaterally
    converted this into an error. This causes an issue for the "dump"
    version of the command. In this case, the devlink region dump will
    always report an invalid argument:
    
    000000000000ffd0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    000000000000ffe0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    devlink answers: Invalid argument
    000000000000fff0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    
    This occurs because the expected flow for the dump is to return 0 after
    there is no further data.
    
    The simplest fix would be to stop converting the error code to -EINVAL
    if start_offset == ret_offset. However, avoid unnecessary work by
    checking for when start_offset is larger than the region size and
    returning 0 upfront.
    
    Fixes: fdd41ec2 ("devlink: Return right error code in case of errors for region read")
    Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
    Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    d5b90e99
devlink.c 212 KB