On 7/22/17 00:56, Mikulas Patocka wrote:
> Hi
>
> Here I send a patch that removes some impossible code from dm-zoned. The
> target also contains large number of GFP_KERNEL allocations, they should
> be changed to GFP_NOIO, if I/O processing could be delayed because of the
> allocation (i.e. anywhere except initialization you should use GFP_NOIO).
>
> Regarding this "if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE)" - could
> this be removed too? Does it really process some zero-sized requests that
> are not flushes? It doesn't seem so.
>
> Mikulas
>
>
> From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
>
> The value REQ_OP_FLUSH is used by the block code in the request structure.
> It is not used in the bio structure.
>
> This patch removes the tests for REQ_OP_FLUSH from dm-zoned-target.
>
> Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
>
> ---
> drivers/md/dm-zoned-target.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Index: linux-2.6/drivers/md/dm-zoned-target.c
> ===================================================================
> --- linux-2.6.orig/drivers/md/dm-zoned-target.c
> +++ linux-2.6/drivers/md/dm-zoned-target.c
> @@ -588,7 +588,7 @@ static int dmz_map(struct dm_target *ti,
>
> bio->bi_bdev = dev->bdev;
>
> - if (!nr_sectors && (bio_op(bio) != REQ_OP_FLUSH) && (bio_op(bio) != REQ_OP_WRITE))
> + if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE)
> return DM_MAPIO_REMAPPED;
>
> /* The BIO should be block aligned */
> @@ -603,7 +603,7 @@ static int dmz_map(struct dm_target *ti,
> bioctx->status = BLK_STS_OK;
>
> /* Set the BIO pending in the flush list */
> - if (bio_op(bio) == REQ_OP_FLUSH || (!nr_sectors && bio_op(bio) == REQ_OP_WRITE)) {
> + if (!nr_sectors && bio_op(bio) == REQ_OP_WRITE) {
> spin_lock(&dmz->flush_lock);
> bio_list_add(&dmz->flush_list, bio);
> spin_unlock(&dmz->flush_lock);
>
Good catch !
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
--
Damien Le Moal,
Western Digital
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