lkml.org 
[lkml]   [2019]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 5.0 89/98] nvmet: fix building bvec from sg list
Date
From: Ming Lei <ming.lei@redhat.com>

[ Upstream commit 02db99548d3608a625cf481cff2bb7b626829b3f ]

There are two mistakes for building bvec from sg list for file
backed ns:

- use request data length to compute number of io vector, this way
doesn't consider sg->offset, and the result may be smaller than required
io vectors

- bvec->bv_len isn't capped by sg->length

This patch fixes this issue by building bvec from sg directly, given
the whole IO stack is ready for multi-page bvec.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: 3a85a5de29ea ("nvme-loop: add a NVMe loopback host driver")

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
drivers/nvme/target/io-cmd-file.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 517522305e5c..9a0fa3943ca7 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -75,11 +75,11 @@ err:
return ret;
}

-static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter)
+static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg)
{
- bv->bv_page = sg_page_iter_page(iter);
- bv->bv_offset = iter->sg->offset;
- bv->bv_len = PAGE_SIZE - iter->sg->offset;
+ bv->bv_page = sg_page(sg);
+ bv->bv_offset = sg->offset;
+ bv->bv_len = sg->length;
}

static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
@@ -128,14 +128,14 @@ 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;
+ ssize_t nr_bvec = req->sg_cnt;
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;
+ struct scatterlist *sg;

if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
is_sync = true;
@@ -147,8 +147,8 @@ 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);
+ for_each_sg(req->sg, sg, req->sg_cnt, i) {
+ nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
len += req->f.bvec[bv_cnt].bv_len;
total_len += req->f.bvec[bv_cnt].bv_len;
bv_cnt++;
@@ -225,7 +225,7 @@ static void nvmet_file_submit_buffered_io(struct nvmet_req *req)

static void nvmet_file_execute_rw(struct nvmet_req *req)
{
- ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
+ ssize_t nr_bvec = req->sg_cnt;

if (!req->sg_cnt || !nr_bvec) {
nvmet_req_complete(req, 0);
--
2.19.1
\
 
 \ /
  Last update: 2019-04-22 22:05    [W:0.320 / U:0.560 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site