Re: [PATCH 3/5] block: remove support for the host aware zone model

[Naohiro Aota]

On Mon, Dec 18, 2023 at 08:21:22AM +0000, Ed Tsai (蔡宗軒) wrote:
> On Mon, 2023-12-18 at 15:53 +0900, Damien Le Moal wrote:
> >  On 2023/12/18 15:15, Ed Tsai (蔡宗軒) wrote:
> > > Hi Christoph,
> > > 
> > > some minor suggestions:
> > > 
> > > On Sun, 2023-12-17 at 17:53 +0100, Christoph Hellwig wrote:
> > >>
> > >> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> > >> index 198d38b53322c1..260b5b8f2b0d7e 100644
> > >> --- a/drivers/md/dm-table.c
> > >> +++ b/drivers/md/dm-table.c
> > >> @@ -1579,21 +1579,18 @@ bool dm_table_has_no_data_devices(struct
> > >> dm_table *t)
> > >>  return true;
> > >>  }
> > >>  
> > >> -static int device_not_zoned_model(struct dm_target *ti, struct
> > >> dm_dev *dev,
> > >> -  sector_t start, sector_t len, void
> > >> *data)
> > >> +static int device_not_zoned(struct dm_target *ti, struct dm_dev
> > >> *dev,
> > >> +    sector_t start, sector_t len, void *data)
> > >>  {
> > >> -struct request_queue *q = bdev_get_queue(dev->bdev);
> > >> -enum blk_zoned_model *zoned_model = data;
> > >> +bool *zoned = data;
> > >>  
> > >> -return blk_queue_zoned_model(q) != *zoned_model;
> > >> +return bdev_is_zoned(dev->bdev) != *zoned;
> > >>  }
> > >>  
> > >>  static int device_is_zoned_model(struct dm_target *ti, struct
> > dm_dev
> > >> *dev,
> > >>   sector_t start, sector_t len, void
> > >> *data)
> > > 
> > > Seems like the word "model" should also be remove here.
> > > 
> > >>  {
> > >> -struct request_queue *q = bdev_get_queue(dev->bdev);
> > >> -
> > >> -return blk_queue_zoned_model(q) != BLK_ZONED_NONE;
> > >> +return bdev_is_zoned(dev->bdev);
> > >>  }
> > >>  
> > >>  /*
> > >> @@ -1603,8 +1600,7 @@ static int device_is_zoned_model(struct
> > >> dm_target *ti, struct dm_dev *dev,
> > >>   * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices
> > can
> > >> have any
> > >>   * zoned model with all zoned devices having the same zone size.
> > >>   */
> > >> -static bool dm_table_supports_zoned_model(struct dm_table *t,
> > >> -  enum blk_zoned_model
> > >> zoned_model)
> > >> +static bool dm_table_supports_zoned(struct dm_table *t, bool
> > zoned)
> > >>  {
> > >>  for (unsigned int i = 0; i < t->num_targets; i++) {
> > >>  struct dm_target *ti = dm_table_get_target(t, i);
> > >> @@ -1623,11 +1619,11 @@ static bool
> > >> dm_table_supports_zoned_model(struct dm_table *t,
> > >>  
> > >>  if (dm_target_supports_zoned_hm(ti->type)) {
> > >>  if (!ti->type->iterate_devices ||
> > >> -    ti->type->iterate_devices(ti,
> > >> device_not_zoned_model,
> > >> -      &zoned_model))
> > >> +    ti->type->iterate_devices(ti,
> > >> device_not_zoned,
> > >> +      &zoned))
> > >>  return false;
> > >>  } else if (!dm_target_supports_mixed_zoned_model(ti-
> > >>> type)) {
> > >> -if (zoned_model == BLK_ZONED_HM)
> > >> +if (zoned)
> > >>  return false;
> > >>  }
> > >>  }
> > > 
> > > The parameter "bool zoned" is redundant. It should be removed from
> > the
> > > above 3 functions
> 
> The two func, is zoned and not zoned, are essentially the same. They
> can be simplified into one function.

Both functions are used for iterate_devices's callback in
dm_table_supports_zoned_model(). As shown in raid_iterate_devices(),
iterate_devices() returns 0 if the callback func calls on all the devices
returns 0, or returns a non-zero result early otherwise. So, the
iterate_devices() call returns "true" if any one of the underlying devices
is (zoned|not zoned).

Since we cannot create lambda as in other fancy languages, we need two
functions...