On 11/12/2020 22:24, Chaitanya Kulkarni wrote:
> Johhanes/Christoph,
>
> On 12/10/20 23:30, Johannes Thumshirn wrote:
>> On 09/12/2020 14:41, Johannes Thumshirn wrote:
>>> On 09/12/2020 11:18, Johannes Thumshirn wrote:
>>>> On 09/12/2020 11:10, hch@xxxxxxxxxxxxx wrote:
>>>>> On Wed, Dec 09, 2020 at 10:08:53AM +0000, Johannes Thumshirn wrote:
>>>>>> On 09/12/2020 10:34, Christoph Hellwig wrote:
>>>>>>> Btw, another thing I noticed:
>>>>>>>
>>>>>>> when using io_uring to submit a write to btrfs that ends up using Zone
>>>>>>> Append we'll hit the
>>>>>>>
>>>>>>> if (WARN_ON_ONCE(is_bvec))
>>>>>>> return -EINVAL;
>>>>>>>
>>>>>>> case in bio_iov_iter_get_pages with the changes in this series.
>>>>>> Yes this warning is totally bogus. It was in there from the beginning of the
>>>>>> zone-append series and I have no idea why I didn't kill it.
>>>>>>
>>>>>> IIRC Chaitanya had a patch in his nvmet zoned series removing it.
>
> Even though that patch is not needed I've tested that with the NVMeOF
> backend to build bios from bvecs with bio_iov_iter_get_pages(), I can still
> send that patch, please confirm.
>
I have the following locally, but I fail to call it in my tests:
commit ea93c91a70204a23ebf9e22b19fbf8add644e12e
Author: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Date: Wed Dec 9 23:26:38 2020 +0900
block: provide __bio_iov_bvec_add_append_pages
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
diff --git a/block/bio.c b/block/bio.c
index 5c6982902330..dc8178ca796f 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -992,6 +992,31 @@ void bio_release_pages(struct bio *bio, bool mark_dirty)
}
EXPORT_SYMBOL_GPL(bio_release_pages);
+static int __bio_iov_bvec_add_append_pages(struct bio *bio,
+ struct iov_iter *iter)
+{
+ const struct bio_vec *bv = iter->bvec;
+ struct request_queue *q = bio->bi_disk->queue;
+ unsigned int max_append_sectors = queue_max_zone_append_sectors(q);
+ unsigned int len;
+ size_t size;
+
+ if (WARN_ON_ONCE(!max_append_sectors))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(iter->iov_offset > bv->bv_len))
+ return -EINVAL;
+
+ len = min_t(size_t, bv->bv_len - iter->iov_offset, iter->count);
+ size = bio_add_hw_page(q, bio, bv->bv_page, len,
+ bv->bv_offset + iter->iov_offset,
+ max_append_sectors, false);
+ if (unlikely(size != len))
+ return -EINVAL;
+ iov_iter_advance(iter, size);
+ return 0;
+}
+
static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter)
{
const struct bio_vec *bv = iter->bvec;
@@ -1142,9 +1167,10 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
do {
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
- if (WARN_ON_ONCE(is_bvec))
- return -EINVAL;
- ret = __bio_iov_append_get_pages(bio, iter);
+ if (is_bvec)
+ ret = __bio_iov_bvec_add_append_pages(bio, iter);
+ else
+ ret = __bio_iov_append_get_pages(bio, iter);
} else {
if (is_bvec)
ret = __bio_iov_bvec_add_pages(bio, iter);
It's basically __bio_iov_bvec_add_pages() respecting the max_zone_sectors queue limit.
