nvmet: fix data_len to 0 for bdev-backed write_zeroes

The WRITE ZEROES command has no data transfer so that we need to
initialize the struct (nvmet_req *req)->data_len to 0x0.  While
(nvmet_req *req)->transfer_len is initialized in nvmet_req_init(),
data_len will be initialized by nowhere which might cause the failure
with status code NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR randomly.  It's
because nvmet_req_execute() checks like:

	if (unlikely(req->data_len != req->transfer_len)) {
		req->error_loc = offsetof(struct nvme_common_command, dptr);
		nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
	} else
		req->execute(req);

This patch fixes req->data_len not to be a randomly assigned by
initializing it to 0x0 when preparing the command in
nvmet_bdev_parse_io_cmd().

nvmet_file_parse_io_cmd() which is for file-backed I/O has already
initialized the data_len field to 0x0, though.

Cc: Christoph Hellwig <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: Chaitanya Kulkarni <[email protected]>
Signed-off-by: Minwoo Im <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>

0 files changed, 0 insertions, 0 deletions