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vhost_blk: set proper vring_used_elem->len

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This `len` field describes the amount of bytes
*written* by the device. It is used to prevent
the driver from reading buffer memory that wasn't
really written to - it could contain either
leftover values from previous requests or even
be completely unitialized.

In a couple of invalid-request error conditions
we still write the VIRTIO_BLK_S_UNSUPP response while
returning used_len == 0, but that's fine. A properly
written driver will likely handle both of these cases
the same way.

Change-Id: I8e9f3a8051561096e2ee755122d534b4ffd94db1
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/393963
Reviewed-by: Pawel Kaminski <pawelx.kaminski@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
This commit is contained in:
Dariusz Stojaczyk 2018-01-08 21:35:53 +01:00 committed by Jim Harris
parent 9605a2eace
commit 60c1cd75dc
1 changed files with 18 additions and 11 deletions
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29
lib/vhost/vhost_blk.c
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@ -56,7 +56,8 @@ struct spdk_vhost_blk_task {
/* If set, the task is currently used for I/O processing. */
bool used;
uint32_t length;
/** Number of bytes that were written. */
uint32_t used_len;
uint16_t iovcnt;
struct iovec iovs[SPDK_VHOST_IOVS_MAX];
};
@ -85,7 +86,8 @@ invalid_blk_request(struct spdk_vhost_blk_task *task, uint8_t status)
*task->status = status;
}
spdk_vhost_vq_used_ring_enqueue(&task->bvdev->vdev, task->vq, task->req_idx, 0);
spdk_vhost_vq_used_ring_enqueue(&task->bvdev->vdev, task->vq, task->req_idx,
task->used_len);
blk_task_finish(task);
SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK_DATA, "Invalid request (status=%" PRIu8")\n", status);
}
@ -162,7 +164,7 @@ blk_request_finish(bool success, struct spdk_vhost_blk_task *task)
{
*task->status = success ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR;
spdk_vhost_vq_used_ring_enqueue(&task->bvdev->vdev, task->vq, task->req_idx,
task->length);
task->used_len);
SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Finished task (%p) req_idx=%d\n status: %s\n", task,
task->req_idx, success ? "OK" : "FAIL");
blk_task_finish(task);
@ -184,9 +186,10 @@ process_blk_request(struct spdk_vhost_blk_task *task, struct spdk_vhost_blk_dev
const struct virtio_blk_outhdr *req;
struct iovec *iov;
uint32_t type;
uint32_t payload_len;
int rc;
if (blk_iovs_setup(&bvdev->vdev, vq, task->req_idx, task->iovs, &task->iovcnt, &task->length)) {
if (blk_iovs_setup(&bvdev->vdev, vq, task->req_idx, task->iovs, &task->iovcnt, &payload_len)) {
SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Invalid request (req_idx = %"PRIu16").\n", task->req_idx);
/* Only READ and WRITE are supported for now. */
invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP);
@ -214,7 +217,7 @@ process_blk_request(struct spdk_vhost_blk_task *task, struct spdk_vhost_blk_dev
}
task->status = iov->iov_base;
task->length -= sizeof(*req) + 1;
payload_len -= sizeof(*req) + sizeof(*task->status);
task->iovcnt -= 2;
type = req->type;
@ -226,7 +229,7 @@ process_blk_request(struct spdk_vhost_blk_task *task, struct spdk_vhost_blk_dev
switch (type) {
case VIRTIO_BLK_T_IN:
case VIRTIO_BLK_T_OUT:
if (spdk_unlikely((task->length & (512 - 1)) != 0)) {
if (spdk_unlikely((payload_len & (512 - 1)) != 0)) {
SPDK_ERRLOG("%s - passed IO buffer is not multiple of 512b (req_idx = %"PRIu16").\n",
type ? "WRITE" : "READ", task->req_idx);
invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP);
@ -234,13 +237,15 @@ process_blk_request(struct spdk_vhost_blk_task *task, struct spdk_vhost_blk_dev
}
if (type == VIRTIO_BLK_T_IN) {
task->used_len = payload_len + sizeof(*task->status);
rc = spdk_bdev_readv(bvdev->bdev_desc, bvdev->bdev_io_channel,
&task->iovs[1], task->iovcnt, req->sector * 512,
task->length, blk_request_complete_cb, task);
payload_len, blk_request_complete_cb, task);
} else if (!bvdev->readonly) {
task->used_len = sizeof(*task->status);
rc = spdk_bdev_writev(bvdev->bdev_desc, bvdev->bdev_io_channel,
&task->iovs[1], task->iovcnt, req->sector * 512,
task->length, blk_request_complete_cb, task);
payload_len, blk_request_complete_cb, task);
} else {
SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Device is in read-only mode!\n");
rc = -1;
@ -252,12 +257,13 @@ process_blk_request(struct spdk_vhost_blk_task *task, struct spdk_vhost_blk_dev
}
break;
case VIRTIO_BLK_T_GET_ID:
if (!task->iovcnt || !task->length) {
if (!task->iovcnt || !payload_len) {
invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP);
return -1;
}
task->length = spdk_min((size_t)VIRTIO_BLK_ID_BYTES, task->iovs[1].iov_len);
spdk_strcpy_pad(task->iovs[1].iov_base, spdk_bdev_get_product_name(bvdev->bdev), task->length, ' ');
task->used_len = spdk_min((size_t)VIRTIO_BLK_ID_BYTES, task->iovs[1].iov_len);
spdk_strcpy_pad(task->iovs[1].iov_base, spdk_bdev_get_product_name(bvdev->bdev),
task->used_len, ' ');
blk_request_finish(true, task);
break;
default:
@ -306,6 +312,7 @@ process_vq(struct spdk_vhost_blk_dev *bvdev, struct spdk_vhost_virtqueue *vq)
task->used = true;
task->iovcnt = SPDK_COUNTOF(task->iovs);
task->status = NULL;
task->used_len = 0;
rc = process_blk_request(task, bvdev, vq);
if (rc == 0) {