Commit 2843fdbd authored Oct 21, 2015 by Matthew R. Ochs Committed by James Bottomley Oct 30, 2015

cxlflash: Fix data corruption when vLUN used over multiple cards



If the same virtual LUN is accessed over multiple cards, only accesses
made over the first card will be valid. Accesses made over the second
card will go to the wrong LUN causing data corruption.

This is because the global LUN's mode word was being used to determine
whether the LUN table for that card needs to be programmed. The mode
word would be setup by the first card, causing the LUN table for the
second card to not be programmed.

By unconditionally initializing the LUN table (not depending on the
mode word), the problem is avoided.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

parent 22fe1ae8

drivers/scsi/cxlflash/vlun.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -915,16 +915,9 @@ int cxlflash_disk_virtual_open(struct scsi_device sdev, void arg)

		pr_debug("%s: ctxid=%llu ls=0x%llx\n", __func__, ctxid, lun_size);

		/* Setup the LUNs block allocator on first call */
		mutex_lock(&gli->mutex);
		if (gli->mode == MODE_NONE) {
		/* Setup the LUN table and block allocator on first call */
		rc = init_luntable(cfg, lli);
		if (rc) {
		dev_err(dev, "%s: call to init_luntable failed "
		"rc=%d!\n", __func__, rc);
		goto err0;
		}

		rc = init_vlun(lli);
		if (rc) {
		dev_err(dev, "%s: call to init_vlun failed rc=%d!\n",
		@@ -942,6 +935,13 @@ int cxlflash_disk_virtual_open(struct scsi_device sdev, void arg)
		}
		mutex_unlock(&gli->mutex);

		rc = init_luntable(cfg, lli);
		if (rc) {
		dev_err(dev, "%s: call to init_luntable failed rc=%d!\n",
		__func__, rc);
		goto err1;
		}

		ctxi = get_context(cfg, rctxid, lli, 0);
		if (unlikely(!ctxi)) {
		dev_err(dev, "%s: Bad context! (%llu)\n", __func__, ctxid);