| Message ID | 1593704330-11540-3-git-send-email-joshi.k@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix/extend zone-append in block-layer | expand |
On 2020/07/03 0:42, Kanchan Joshi wrote: > zone-append with bvec iov_iter gives WARN_ON, and returns -EINVAL. > Add new helper to process such iov_iter and add pages in bio honoring > zone-append specific constraints. > > Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> > Signed-off-by: Selvakumar S <selvakuma.s1@samsung.com> > Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com> > Signed-off-by: Javier Gonzalez <javier.gonz@samsung.com> > --- > block/bio.c | 31 ++++++++++++++++++++++++++++--- > 1 file changed, 28 insertions(+), 3 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index 0cecdbc..ade9da7 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -975,6 +975,30 @@ static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) > iov_iter_advance(iter, size); > return 0; > } > +static int __bio_iov_bvec_append_add_pages(struct bio *bio, struct iov_iter *iter) > +{ > + const struct bio_vec *bv = iter->bvec; > + unsigned int len; > + size_t size; > + struct request_queue *q = bio->bi_disk->queue; > + unsigned int max_append_sectors = queue_max_zone_append_sectors(q); > + bool same_page = false; > + > + 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, &same_page); > + if (unlikely(size != len)) > + return -EINVAL; > + iov_iter_advance(iter, size); > + return 0; > +} > > #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) > > @@ -1105,9 +1129,10 @@ 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_append_add_pages(bio, iter); > + else > + ret = __bio_iov_append_get_pages(bio, iter); > } else { > if (is_bvec) > ret = __bio_iov_bvec_add_pages(bio, iter); > The only user of this function that issues zone append requests is zonefs. The issued requests are not using bvec iter but a user direct IO buffer iter. So this change would have no user at all as far as I can see. Am I missing something ? What IO path makes this change necessary ?
On Fri, Jul 03, 2020 at 05:32:56AM +0000, Damien Le Moal wrote: >On 2020/07/03 0:42, Kanchan Joshi wrote: >> zone-append with bvec iov_iter gives WARN_ON, and returns -EINVAL. >> Add new helper to process such iov_iter and add pages in bio honoring >> zone-append specific constraints. >> >> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> >> Signed-off-by: Selvakumar S <selvakuma.s1@samsung.com> >> Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com> >> Signed-off-by: Javier Gonzalez <javier.gonz@samsung.com> >> --- >> block/bio.c | 31 ++++++++++++++++++++++++++++--- >> 1 file changed, 28 insertions(+), 3 deletions(-) >> >> diff --git a/block/bio.c b/block/bio.c >> index 0cecdbc..ade9da7 100644 >> --- a/block/bio.c >> +++ b/block/bio.c >> @@ -975,6 +975,30 @@ static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) >> iov_iter_advance(iter, size); >> return 0; >> } >> +static int __bio_iov_bvec_append_add_pages(struct bio *bio, struct iov_iter *iter) >> +{ >> + const struct bio_vec *bv = iter->bvec; >> + unsigned int len; >> + size_t size; >> + struct request_queue *q = bio->bi_disk->queue; >> + unsigned int max_append_sectors = queue_max_zone_append_sectors(q); >> + bool same_page = false; >> + >> + 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, &same_page); >> + if (unlikely(size != len)) >> + return -EINVAL; >> + iov_iter_advance(iter, size); >> + return 0; >> +} >> >> #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) >> >> @@ -1105,9 +1129,10 @@ 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_append_add_pages(bio, iter); >> + else >> + ret = __bio_iov_append_get_pages(bio, iter); >> } else { >> if (is_bvec) >> ret = __bio_iov_bvec_add_pages(bio, iter); >> > >The only user of this function that issues zone append requests is zonefs. The >issued requests are not using bvec iter but a user direct IO buffer iter. So >this change would have no user at all as far as I can see. Am I missing >something ? What IO path makes this change necessary ? Yes, zonefs does not use bvec iter. But while enabling io-uring path for zone-append, I hit into this condition returning -EINVAL. Reference (from user zone-append series cover letter): "Append using io_uring fixed-buffer ---> This is flagged as not-supported at the moment. Reason being, for fixed-buffer io-uring sends iov_iter of bvec type. But current append-infra in block-layer does not support such iov_iter." And zone-append doesn't have a problem in using bvec iter as well, so thought that this may make infra more complete/future-proof? >-- >Damien Le Moal >Western Digital Research >
On 2020/07/03 15:56, Kanchan Joshi wrote: > On Fri, Jul 03, 2020 at 05:32:56AM +0000, Damien Le Moal wrote: >> On 2020/07/03 0:42, Kanchan Joshi wrote: >>> zone-append with bvec iov_iter gives WARN_ON, and returns -EINVAL. >>> Add new helper to process such iov_iter and add pages in bio honoring >>> zone-append specific constraints. >>> >>> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> >>> Signed-off-by: Selvakumar S <selvakuma.s1@samsung.com> >>> Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com> >>> Signed-off-by: Javier Gonzalez <javier.gonz@samsung.com> >>> --- >>> block/bio.c | 31 ++++++++++++++++++++++++++++--- >>> 1 file changed, 28 insertions(+), 3 deletions(-) >>> >>> diff --git a/block/bio.c b/block/bio.c >>> index 0cecdbc..ade9da7 100644 >>> --- a/block/bio.c >>> +++ b/block/bio.c >>> @@ -975,6 +975,30 @@ static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) >>> iov_iter_advance(iter, size); >>> return 0; >>> } >>> +static int __bio_iov_bvec_append_add_pages(struct bio *bio, struct iov_iter *iter) >>> +{ >>> + const struct bio_vec *bv = iter->bvec; >>> + unsigned int len; >>> + size_t size; >>> + struct request_queue *q = bio->bi_disk->queue; >>> + unsigned int max_append_sectors = queue_max_zone_append_sectors(q); >>> + bool same_page = false; >>> + >>> + 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, &same_page); >>> + if (unlikely(size != len)) >>> + return -EINVAL; >>> + iov_iter_advance(iter, size); >>> + return 0; >>> +} >>> >>> #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) >>> >>> @@ -1105,9 +1129,10 @@ 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_append_add_pages(bio, iter); >>> + else >>> + ret = __bio_iov_append_get_pages(bio, iter); >>> } else { >>> if (is_bvec) >>> ret = __bio_iov_bvec_add_pages(bio, iter); >>> >> >> The only user of this function that issues zone append requests is zonefs. The >> issued requests are not using bvec iter but a user direct IO buffer iter. So >> this change would have no user at all as far as I can see. Am I missing >> something ? What IO path makes this change necessary ? > > Yes, zonefs does not use bvec iter. But while enabling io-uring path for > zone-append, I hit into this condition returning -EINVAL. > > Reference (from user zone-append series cover letter): > "Append using io_uring fixed-buffer ---> > This is flagged as not-supported at the moment. Reason being, for fixed-buffer > io-uring sends iov_iter of bvec type. But current append-infra in block-layer > does not support such iov_iter." > > And zone-append doesn't have a problem in using bvec iter as well, so > thought that this may make infra more complete/future-proof? As long as there is no possible user for this change, I do not see the point in adding it.
On 03/07/2020 08:56, Kanchan Joshi wrote: [...] > Yes, zonefs does not use bvec iter. But while enabling io-uring path for > zone-append, I hit into this condition returning -EINVAL. > > Reference (from user zone-append series cover letter): > "Append using io_uring fixed-buffer ---> > This is flagged as not-supported at the moment. Reason being, for fixed-buffer > io-uring sends iov_iter of bvec type. But current append-infra in block-layer > does not support such iov_iter." > > And zone-append doesn't have a problem in using bvec iter as well, so > thought that this may make infra more complete/future-proof? As long as it's no problem for current in-tree users please keep it as is. Please submit this patch together with your io_uring series as a preparatory patch.
diff --git a/block/bio.c b/block/bio.c index 0cecdbc..ade9da7 100644 --- a/block/bio.c +++ b/block/bio.c @@ -975,6 +975,30 @@ static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) iov_iter_advance(iter, size); return 0; } +static int __bio_iov_bvec_append_add_pages(struct bio *bio, struct iov_iter *iter) +{ + const struct bio_vec *bv = iter->bvec; + unsigned int len; + size_t size; + struct request_queue *q = bio->bi_disk->queue; + unsigned int max_append_sectors = queue_max_zone_append_sectors(q); + bool same_page = false; + + 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, &same_page); + if (unlikely(size != len)) + return -EINVAL; + iov_iter_advance(iter, size); + return 0; +} #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) @@ -1105,9 +1129,10 @@ 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_append_add_pages(bio, iter); + else + ret = __bio_iov_append_get_pages(bio, iter); } else { if (is_bvec) ret = __bio_iov_bvec_add_pages(bio, iter);