* [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() [not found] <20190325100708.24172-1-ming.lei@redhat.com> @ 2019-03-25 10:07 ` Ming Lei 2019-03-25 10:52 ` Christoph Hellwig 0 siblings, 1 reply; 6+ messages in thread From: Ming Lei @ 2019-03-25 10:07 UTC (permalink / raw) To: linux-nvme, Christoph Hellwig Cc: Ming Lei, Yi Zhang, Sagi Grimberg, Chaitanya Kulkarni, stable There isn't sg iterator helper for building bvec, so invent one and fix the issue in nvmet_file_init_bvec(). The issue is that one sg may include multipge continuous pages, and only the 1st .bv_offset isn't zero, also the length for the last bvec has to consider the remained length. Reported-by: Yi Zhang <yi.zhang@redhat.com> Fixes: d5eff33ee6f8("nvmet: add simple file backed ns support") Cc: Yi Zhang <yi.zhang@redhat.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/nvme/target/io-cmd-file.c | 57 ++++++++++++++++++++------------------- 1 file changed, 29 insertions(+), 28 deletions(-) diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c index 3e43212d3c1c..1c76e9e2a474 100644 --- a/drivers/nvme/target/io-cmd-file.c +++ b/drivers/nvme/target/io-cmd-file.c @@ -75,13 +75,6 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns) return ret; } -static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter) -{ - bv->bv_page = sg_page_iter_page(iter); - bv->bv_offset = iter->sg->offset; - bv->bv_len = PAGE_SIZE - iter->sg->offset; -} - static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos, unsigned long nr_segs, size_t count, int ki_flags) { @@ -129,13 +122,14 @@ static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2) static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) { ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE); - struct sg_page_iter sg_pg_iter; + struct scatterlist *sg; + struct bio_vec *bv; unsigned long bv_cnt = 0; bool is_sync = false; size_t len = 0, total_len = 0; ssize_t ret = 0; loff_t pos; - + int i, j, sg_done; if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC) is_sync = true; @@ -147,26 +141,33 @@ static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) } memset(&req->f.iocb, 0, sizeof(struct kiocb)); - for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) { - nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter); - len += req->f.bvec[bv_cnt].bv_len; - total_len += req->f.bvec[bv_cnt].bv_len; - bv_cnt++; - - WARN_ON_ONCE((nr_bvec - 1) < 0); - - if (unlikely(is_sync) && - (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { - ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0); - if (ret < 0) - goto complete; - - pos += len; - bv_cnt = 0; - len = 0; + for_each_sg(req->sg, sg, req->sg_cnt, i) + for (j = 0, sg_done = 0; + (bv = &req->f.bvec[bv_cnt]) && sg_done < sg->length; + j++, sg_done += bv->bv_len) { + bv->bv_offset = j ? 0 : sg->offset; + bv->bv_len = min_t(unsigned, PAGE_SIZE - bv->bv_offset, + sg->length - sg_done); + bv->bv_page = nth_page(sg_page(sg), j); + + len += bv->bv_len; + total_len += bv->bv_len; + bv_cnt++; + + WARN_ON_ONCE((nr_bvec - 1) < 0); + + if (unlikely(is_sync) && + (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { + ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0); + if (ret < 0) + goto complete; + + pos += len; + bv_cnt = 0; + len = 0; + } + nr_bvec--; } - nr_bvec--; - } if (WARN_ON_ONCE(total_len != req->data_len)) { ret = -EIO; -- 2.9.5 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() 2019-03-25 10:07 ` [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() Ming Lei @ 2019-03-25 10:52 ` Christoph Hellwig 2019-03-26 1:39 ` Ming Lei 0 siblings, 1 reply; 6+ messages in thread From: Christoph Hellwig @ 2019-03-25 10:52 UTC (permalink / raw) To: Ming Lei Cc: linux-nvme, Christoph Hellwig, Yi Zhang, Sagi Grimberg, Chaitanya Kulkarni, stable On Mon, Mar 25, 2019 at 06:07:07PM +0800, Ming Lei wrote: > There isn't sg iterator helper for building bvec, so invent one > and fix the issue in nvmet_file_init_bvec(). > > The issue is that one sg may include multipge continuous pages, and > only the 1st .bv_offset isn't zero, also the length for the last bvec > has to consider the remained length. The scatterlist in the nvme target is always allocated by the nvmet code itself an thus never contains multi-page sg list entries. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() 2019-03-25 10:52 ` Christoph Hellwig @ 2019-03-26 1:39 ` Ming Lei 2019-03-26 2:03 ` Sagi Grimberg 0 siblings, 1 reply; 6+ messages in thread From: Ming Lei @ 2019-03-26 1:39 UTC (permalink / raw) To: Christoph Hellwig Cc: Yi Zhang, Sagi Grimberg, Chaitanya Kulkarni, stable, linux-nvme On Mon, Mar 25, 2019 at 11:52:31AM +0100, Christoph Hellwig wrote: > On Mon, Mar 25, 2019 at 06:07:07PM +0800, Ming Lei wrote: > > There isn't sg iterator helper for building bvec, so invent one > > and fix the issue in nvmet_file_init_bvec(). > > > > The issue is that one sg may include multipge continuous pages, and > > only the 1st .bv_offset isn't zero, also the length for the last bvec > > has to consider the remained length. > > The scatterlist in the nvme target is always allocated by the nvmet > code itself an thus never contains multi-page sg list entries. I am wondering if it is true. Not look at other target code yet, however seems it isn't true for loop, see the following code in nvme_loop_queue_rq(): iod->req.sg = iod->sg_table.sgl; iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl); iod->req.transfer_len = blk_rq_payload_bytes(req); And it has been triggered by nvme/011 in Yi's test. Thanks, Ming ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() 2019-03-26 1:39 ` Ming Lei @ 2019-03-26 2:03 ` Sagi Grimberg 2019-03-26 2:16 ` Ming Lei 0 siblings, 1 reply; 6+ messages in thread From: Sagi Grimberg @ 2019-03-26 2:03 UTC (permalink / raw) To: Ming Lei, Christoph Hellwig Cc: Yi Zhang, Chaitanya Kulkarni, stable, linux-nvme >> The scatterlist in the nvme target is always allocated by the nvmet >> code itself an thus never contains multi-page sg list entries. > > I am wondering if it is true. > > Not look at other target code yet, however seems it isn't true for loop, > see the following code in nvme_loop_queue_rq(): > > iod->req.sg = iod->sg_table.sgl; > iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl); > iod->req.transfer_len = blk_rq_payload_bytes(req); > > And it has been triggered by nvme/011 in Yi's test. Yes, loop is an exception in this case. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() 2019-03-26 2:03 ` Sagi Grimberg @ 2019-03-26 2:16 ` Ming Lei 2019-03-26 7:32 ` Christoph Hellwig 0 siblings, 1 reply; 6+ messages in thread From: Ming Lei @ 2019-03-26 2:16 UTC (permalink / raw) To: Sagi Grimberg Cc: Christoph Hellwig, linux-nvme, Yi Zhang, stable, Chaitanya Kulkarni On Mon, Mar 25, 2019 at 07:03:23PM -0700, Sagi Grimberg wrote: > > > > The scatterlist in the nvme target is always allocated by the nvmet > > > code itself an thus never contains multi-page sg list entries. > > > > I am wondering if it is true. > > > > Not look at other target code yet, however seems it isn't true for loop, > > see the following code in nvme_loop_queue_rq(): > > > > iod->req.sg = iod->sg_table.sgl; > > iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl); > > iod->req.transfer_len = blk_rq_payload_bytes(req); > > > > And it has been triggered by nvme/011 in Yi's test. > > Yes, loop is an exception in this case. Thanks for the clarification! Another candidate fix is to set nvmet-loop's queue segment boundary mask as PAGE_SIZE - 1. Also there is the same issue for block device backed target. If no one objects, I'd like to take the approach of adjusting segment boundary mask. Thanks, Ming ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() 2019-03-26 2:16 ` Ming Lei @ 2019-03-26 7:32 ` Christoph Hellwig 0 siblings, 0 replies; 6+ messages in thread From: Christoph Hellwig @ 2019-03-26 7:32 UTC (permalink / raw) To: Ming Lei Cc: Sagi Grimberg, Christoph Hellwig, linux-nvme, Yi Zhang, stable, Chaitanya Kulkarni On Tue, Mar 26, 2019 at 10:16:28AM +0800, Ming Lei wrote: > Also there is the same issue for block device backed target. > > If no one objects, I'd like to take the approach of adjusting segment > boundary mask. Just go for the merge of your two patches. That fixes the issue and actually makes the code simpler. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-03-26 7:32 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <20190325100708.24172-1-ming.lei@redhat.com>
2019-03-25 10:07 ` [PATCH 1/2] nvme: target: fix nvmet_file_init_bvec() Ming Lei
2019-03-25 10:52 ` Christoph Hellwig
2019-03-26 1:39 ` Ming Lei
2019-03-26 2:03 ` Sagi Grimberg
2019-03-26 2:16 ` Ming Lei
2019-03-26 7:32 ` Christoph Hellwig
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).