scsi: fnic: replace gross legacy tag hack with blk-mq hack (4d5b4ac1) · Commits · 戴 / test

drivers/scsi/fnic/fnic_scsi.c

+12 −49

Original line number	Diff line number	Diff line
		@@ -2266,33 +2266,17 @@ clean_pending_aborts_end:
		static inline int
		fnic_scsi_host_start_tag(struct fnic fnic, struct scsi_cmnd sc)
		{
		struct blk_queue_tag *bqt = fnic->lport->host->bqt;
		int tag, ret = SCSI_NO_TAG;
		struct request_queue *q = sc->request->q;
		struct request *dummy;

		BUG_ON(!bqt);
		if (!bqt) {
		pr_err("Tags are not supported\n");
		goto end;
		}

		do {
		tag = find_next_zero_bit(bqt->tag_map, bqt->max_depth, 1);
		if (tag >= bqt->max_depth) {
		pr_err("Tag allocation failure\n");
		goto end;
		}
		} while (test_and_set_bit(tag, bqt->tag_map));
		dummy = blk_mq_alloc_request(q, REQ_OP_WRITE, BLK_MQ_REQ_NOWAIT);
		if (IS_ERR(dummy))
		return SCSI_NO_TAG;

		bqt->tag_index[tag] = sc->request;
		sc->request->tag = tag;
		sc->tag = tag;
		if (!sc->request->special)
		sc->tag = sc->request->tag = dummy->tag;
		sc->request->special = sc;

		ret = tag;

		end:
		return ret;
		return dummy->tag;
		}

		/**
		@@ -2302,20 +2286,9 @@ end:
		static inline void
		fnic_scsi_host_end_tag(struct fnic fnic, struct scsi_cmnd sc)
		{
		struct blk_queue_tag *bqt = fnic->lport->host->bqt;
		int tag = sc->request->tag;

		if (tag == SCSI_NO_TAG)
		return;
		struct request *dummy = sc->request->special;

		BUG_ON(!bqt \|\| !bqt->tag_index[tag]);
		if (!bqt)
		return;

		bqt->tag_index[tag] = NULL;
		clear_bit(tag, bqt->tag_map);

		return;
		blk_mq_free_request(dummy);
		}

		/*
		@@ -2374,19 +2347,9 @@ int fnic_device_reset(struct scsi_cmnd *sc)
		tag = sc->request->tag;
		if (unlikely(tag < 0)) {
		/*
		* XXX(hch): current the midlayer fakes up a struct
		* request for the explicit reset ioctls, and those
		* don't have a tag allocated to them. The below
		* code pokes into midlayer structures to paper over
		* this design issue, but that won't work for blk-mq.
		*
		* Either someone who can actually test the hardware
		* will have to come up with a similar hack for the
		* blk-mq case, or we'll have to bite the bullet and
		* fix the way the EH ioctls work for real, but until
		* that happens we fail these explicit requests here.
		* Really should fix the midlayer to pass in a proper
		* request for ioctls...
		*/

		tag = fnic_scsi_host_start_tag(fnic, sc);
		if (unlikely(tag == SCSI_NO_TAG))
		goto fnic_device_reset_end;

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