Mention sg ioengine requires filename option

similar to the way net ioengine documents filename option.

Also bring in a file type check from fio_sgio_type_check()
to avoid pointless read capacity error against regfiles.

Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/HOWTO b/HOWTO
index 4cc733f60e01c728ecbc3d64b7b32114d060d8fd..33f8718a94d0352f995827f63ed3384f83d9cd63 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -819,7 +819,8 @@ ioengine=str        Defines how the job issues io to the file. The following
                                synchronous using the SG_IO ioctl, or if
                                the target is an sg character device
                                we use read(2) and write(2) for asynchronous
                                synchronous using the SG_IO ioctl, or if
                                the target is an sg character device
                                we use read(2) and write(2) for asynchronous

-                               io.
+                               io. Requires filename option to specify either
+                               block or character devices.

 
                        null    Doesn't transfer any data, just pretends
                                to. This is mainly used to exercise fio
 
                        null    Doesn't transfer any data, just pretends
                                to. This is mainly used to exercise fio

diff --git a/engines/sg.c b/engines/sg.c
index e70803c8445f2892985ea85e7d77b6a192acb392..3f7d9110e71fdff6740869f9cd956f020dc72fb2 100644 (file)
--- a/engines/sg.c
+++ b/engines/sg.c
@@ -525,7 +525,7 @@ static int fio_sgio_type_check(struct thread_data *td, struct fio_file *f)
                }
        } else {
                td_verror(td, EINVAL, "wrong file type");
                }
        } else {
                td_verror(td, EINVAL, "wrong file type");

-               log_err("ioengine sg only works on block devices\n");
+               log_err("ioengine sg only works on block or character devices\n");

                return 1;
        }
 
                return 1;
        }
 


@@ -789,6 +789,12 @@ static int fio_sgio_get_file_size(struct thread_data *td, struct fio_file *f)
        if (fio_file_size_known(f))
                return 0;
 
        if (fio_file_size_known(f))
                return 0;
 

+       if (f->filetype != FIO_TYPE_BD && f->filetype != FIO_TYPE_CHAR) {
+               td_verror(td, EINVAL, "wrong file type");
+               log_err("ioengine sg only works on block or character devices\n");
+               return 1;
+       }
+

        ret = fio_sgio_read_capacity(td, &bs, &max_lba);
        if (ret ) {
                td_verror(td, td->error, "fio_sgio_read_capacity");
        ret = fio_sgio_read_capacity(td, &bs, &max_lba);
        if (ret ) {
                td_verror(td, td->error, "fio_sgio_read_capacity");