On Aug 03, 2021 / 19:36, Dmitry Fomichev wrote:
> On Wed, 2021-07-28 at 19:47 +0900, Shin'ichiro Kawasaki wrote:
> > The trim workload to zoned block devices is supported as zone reset,
> > and
> > this feature is available for I/O engines which support both zoned
> > devices and trim workload. Libzbc I/O engine supports zoned but lacks
> > trim workload support. To enable trim support with libzbc I/O engine,
> > remove the check which inhibited trim from requests to libzbc I/O
> > engine. Also set file open flags for trim same as write, and call
> > zbd_do_io_u_trim() for trim I/O.
> >
> > Of note is that libzbc I/O engine now can support trim to sequential
> > write required zones, but still can not support os_trim() call and
> > BLKDISCARD ioctl for the conventional zones. The trim I/Os to
> > conventional zones are reported as an error.
> >
> > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> > ---
> > engines/libzbc.c | 16 ++++++++++------
> > 1 file changed, 10 insertions(+), 6 deletions(-)
> >
> > diff --git a/engines/libzbc.c b/engines/libzbc.c
> > index 7f2bc431..5b4c5e8e 100644
> > --- a/engines/libzbc.c
> > +++ b/engines/libzbc.c
> > @@ -14,6 +14,7 @@
> > #include "fio.h"
> > #include "err.h"
> > #include "zbd_types.h"
> > +#include "zbd.h"
> >
> > struct libzbc_data {
> > struct zbc_device *zdev;
> > @@ -63,7 +64,7 @@ static int libzbc_open_dev(struct thread_data *td,
> > struct fio_file *f,
> > return -EINVAL;
> > }
> >
> > - if (td_write(td)) {
> > + if (td_write(td) || td_trim(td)) {
> > if (!read_only)
> > flags |= O_RDWR;
> > } else if (td_read(td)) {
> > @@ -71,10 +72,6 @@ static int libzbc_open_dev(struct thread_data *td,
> > struct fio_file *f,
> > flags |= O_RDWR;
> > else
> > flags |= O_RDONLY;
> > - } else if (td_trim(td)) {
> > - td_verror(td, EINVAL, "libzbc does not support
> > trim");
> > - log_err("%s: libzbc does not support trim\n", f-
> > >file_name);
> > - return -EINVAL;
> > }
> >
> > if (td->o.oatomic) {
> > @@ -411,7 +408,14 @@ static enum fio_q_status libzbc_queue(struct
> > thread_data *td, struct io_u *io_u)
> > ret = zbc_flush(ld->zdev);
> > if (ret)
> > log_err("zbc_flush error %zd\n", ret);
> > - } else if (io_u->ddir != DDIR_TRIM) {
> > + } else if (io_u->ddir == DDIR_TRIM) {
> > + ret = zbd_do_io_u_trim(td, io_u);
> > + if (!ret) {
> > + log_err("libzbc does not support trim to "
> > + "conventional zones\n");
> > + ret = EINVAL;
>
> Wouldn't that be more appropriate to just call os_trim() here and avoid
> this error? This way, any ZBD trim workload that succeeds without using
> libzbc would also succeed with using this engine... not the case with
> the code above.
os_trim() for Linux calls BLKDISCARD ioctl, which does not work for SG node.
Then, os_trim() call is not appropriate here.
One point to improve is the log_err() message I added. "Trim" and
"Conventional zone" does not have relation, then the message is confusing.
The error message is too much, probably. I will remove it and just return
EINVAL.
>
> > + }
> > + } else {
> > log_err("Unsupported operation %u\n", io_u->ddir);
> > ret = -EINVAL;
> > }
>
--
Best Regards,
Shin'ichiro Kawasaki
