Commit 02db9954 authored by Ming Lei's avatar Ming Lei Committed by Christoph Hellwig

nvmet: fix building bvec from sg list

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: default avatarYi Zhang <yi.zhang@redhat.com>
Fixes: 3a85a5de ("nvme-loop: add a NVMe loopback host driver")
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent cc2278c4
...@@ -75,11 +75,11 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns) ...@@ -75,11 +75,11 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns)
return ret; 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_page = sg_page(sg);
bv->bv_offset = iter->sg->offset; bv->bv_offset = sg->offset;
bv->bv_len = PAGE_SIZE - iter->sg->offset; bv->bv_len = sg->length;
} }
static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos, 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) ...@@ -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) 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); ssize_t nr_bvec = req->sg_cnt;
struct sg_page_iter sg_pg_iter;
unsigned long bv_cnt = 0; unsigned long bv_cnt = 0;
bool is_sync = false; bool is_sync = false;
size_t len = 0, total_len = 0; size_t len = 0, total_len = 0;
ssize_t ret = 0; ssize_t ret = 0;
loff_t pos; loff_t pos;
int i;
struct scatterlist *sg;
if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC) if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
is_sync = true; is_sync = true;
...@@ -147,8 +147,8 @@ static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) ...@@ -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)); memset(&req->f.iocb, 0, sizeof(struct kiocb));
for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) { for_each_sg(req->sg, sg, req->sg_cnt, i) {
nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter); nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
len += req->f.bvec[bv_cnt].bv_len; len += req->f.bvec[bv_cnt].bv_len;
total_len += req->f.bvec[bv_cnt].bv_len; total_len += req->f.bvec[bv_cnt].bv_len;
bv_cnt++; bv_cnt++;
...@@ -225,7 +225,7 @@ static void nvmet_file_submit_buffered_io(struct nvmet_req *req) ...@@ -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) 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) { if (!req->sg_cnt || !nr_bvec) {
nvmet_req_complete(req, 0); nvmet_req_complete(req, 0);
......
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