Commit 166f6e9c authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Ben Walker
Browse files

bdev/virtio: add rescan safety checks 



Don't allow starting full device rescan
if such scan is already in progress.

This patch also makes it possible to
start a full scan while only particular
targets are being rescanned.

Change-Id: I8677f640a4e5d9d8c486dfe1e9a58331e941a461
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/392373


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 5eea99fc

lib/bdev/virtio/bdev_virtio.c

+41 −10
Original line number Diff line number Diff line
@@ -130,6 +130,9 @@ struct virtio_scsi_scan_base { 
	/** Scan all targets on the device. */

	bool				full_scan;



	/** Start a full rescan after receiving next scan I/O response. */

	bool				restart;



	/** Additional targets to be (re)scanned. */

	TAILQ_HEAD(, virtio_scsi_scan_info) scan_queue;
@@ -697,6 +700,7 @@ bdev_virtio_poll(void *arg) 
{

	struct bdev_virtio_io_channel *ch = arg;

	struct virtio_scsi_dev *svdev = ch->svdev;

	struct virtio_scsi_scan_base *scan_ctx = svdev->scan_ctx;

	void *io[32];

	uint32_t io_len[32];

	uint16_t i, cnt;
@@ -704,34 +708,41 @@ bdev_virtio_poll(void *arg) 


	cnt = virtio_recv_pkts(ch->vq, (void **)io, io_len, SPDK_COUNTOF(io));

	for (i = 0; i < cnt; ++i) {

		if (spdk_unlikely(svdev->scan_ctx && io[i] == &svdev->scan_ctx->io_ctx)) {

		if (spdk_unlikely(scan_ctx && io[i] == &scan_ctx->io_ctx)) {

			if (svdev->removed) {

				_virtio_scsi_dev_scan_finish(svdev->scan_ctx, -EINTR);

				_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);

				return;

			}



			process_scan_resp(svdev->scan_ctx);

			if (scan_ctx->restart) {

				scan_ctx->restart = false;

				scan_ctx->full_scan = true;

				_virtio_scsi_dev_scan_tgt(scan_ctx, 0);

				continue;

			}



			process_scan_resp(scan_ctx);

			continue;

		}



		bdev_virtio_io_cpl(io[i]);

	}



	if (spdk_unlikely(svdev->scan_ctx && svdev->scan_ctx->needs_resend)) {

	if (spdk_unlikely(scan_ctx && scan_ctx->needs_resend)) {

		if (svdev->removed) {

			_virtio_scsi_dev_scan_finish(svdev->scan_ctx, -EINTR);

			_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);

			return;

		} else if (cnt == 0) {

			return;

		}



		rc = send_scan_io(svdev->scan_ctx);

		rc = send_scan_io(scan_ctx);

		if (rc != 0) {

			assert(svdev->scan_ctx->retries > 0);

			svdev->scan_ctx->retries--;

			if (svdev->scan_ctx->retries == 0) {

			assert(scan_ctx->retries > 0);

			scan_ctx->retries--;

			if (scan_ctx->retries == 0) {

				SPDK_ERRLOG("Target scan failed unrecoverably with rc = %d.\n", rc);

				_virtio_scsi_dev_scan_finish(svdev->scan_ctx, rc);

				_virtio_scsi_dev_scan_finish(scan_ctx, rc);

			}

		}

	}
@@ -1511,8 +1522,28 @@ virtio_scsi_dev_scan(struct virtio_scsi_dev *svdev, bdev_virtio_create_cb cb_fn, 
		     void *cb_arg)

{

	struct virtio_scsi_scan_base *base;

	struct virtio_scsi_scan_info *tgt, *next_tgt;

	int rc;



	if (svdev->scan_ctx) {

		if (svdev->scan_ctx->full_scan) {

			return -EEXIST;

		}



		/* We're about to start a full rescan, so there's no need

		 * to scan particular targets afterwards.

		 */

		TAILQ_FOREACH_SAFE(tgt, &svdev->scan_ctx->scan_queue, tailq, next_tgt) {

			TAILQ_REMOVE(&svdev->scan_ctx->scan_queue, tgt, tailq);

			free(tgt);

		}



		svdev->scan_ctx->cb_fn = cb_fn;

		svdev->scan_ctx->cb_arg = cb_arg;

		svdev->scan_ctx->restart = true;

		return 0;

	}



	rc = _virtio_scsi_dev_scan_init(svdev);

	if (rc != 0) {

		return rc;