scsi: mpi3mr: Rework mrioc->bsg_device model to fix warnings

During driver unload, mrioc->bsg_device reference count becomes
negative. Also, as reported in [1], the driver's bsg_device model had few
more bugs. Fix all these up.

[1] https://marc.info/?l=linux-scsi&m=165183971411991&w=2

Link: https://lore.kernel.org/r/20220526170157.58274-1-sumit.saxena@broadcom.com
Fixes: 4268fa751365 ("scsi: mpi3mr: Add bsg device support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index 01cd01787b0feb57c9a7cfa4706dd7d6cc093284..0e1cb4aa4ca270a8333457c804a72efb7307ebfb 100644 (file)
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -954,7 +954,7 @@ struct mpi3mr_ioc {
        u16 active_poll_qcount;
        u16 requested_poll_qcount;
 
-       struct device *bsg_dev;
+       struct device bsg_dev;
        struct request_queue *bsg_queue;
        u8 stop_bsgs;
        u8 *logdata_buf;

diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
index 9ab1762468ad6ee9ae03483404ec77440eab5ae9..29ed64a572ea62516849e08d0edcade5dac6db22 100644 (file)
--- a/drivers/scsi/mpi3mr/mpi3mr_app.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
@@ -1487,28 +1487,28 @@ static int mpi3mr_bsg_request(struct bsg_job *job)
  */
 void mpi3mr_bsg_exit(struct mpi3mr_ioc *mrioc)
 {
+       struct device *bsg_dev = &mrioc->bsg_dev;
        if (!mrioc->bsg_queue)
                return;
 
        bsg_remove_queue(mrioc->bsg_queue);
        mrioc->bsg_queue = NULL;
 
-       device_del(mrioc->bsg_dev);
-       put_device(mrioc->bsg_dev);
-       kfree(mrioc->bsg_dev);
+       device_del(bsg_dev);
+       put_device(bsg_dev);
 }
 
 /**
  * mpi3mr_bsg_node_release -release bsg device node
  * @dev: bsg device node
  *
- * decrements bsg dev reference count
+ * decrements bsg dev parent reference count
  *
  * Return:Nothing
  */
 static void mpi3mr_bsg_node_release(struct device *dev)
 {
-       put_device(dev);
+       put_device(dev->parent);
 }
 
 /**
@@ -1521,41 +1521,37 @@ static void mpi3mr_bsg_node_release(struct device *dev)
  */
 void mpi3mr_bsg_init(struct mpi3mr_ioc *mrioc)
 {
-       mrioc->bsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
-       if (!mrioc->bsg_dev) {
-               ioc_err(mrioc, "bsg device mem allocation failed\n");
-               return;
-       }
+       struct device *bsg_dev = &mrioc->bsg_dev;
+       struct device *parent = &mrioc->shost->shost_gendev;
+
+       device_initialize(bsg_dev);
+
+       bsg_dev->parent = get_device(parent);
+       bsg_dev->release = mpi3mr_bsg_node_release;
 
-       device_initialize(mrioc->bsg_dev);
-       dev_set_name(mrioc->bsg_dev, "mpi3mrctl%u", mrioc->id);
+       dev_set_name(bsg_dev, "mpi3mrctl%u", mrioc->id);
 
-       if (device_add(mrioc->bsg_dev)) {
+       if (device_add(bsg_dev)) {
                ioc_err(mrioc, "%s: bsg device add failed\n",
-                   dev_name(mrioc->bsg_dev));
-               goto err_device_add;
+                   dev_name(bsg_dev));
+               put_device(bsg_dev);
+               return;
        }
 
-       mrioc->bsg_dev->release = mpi3mr_bsg_node_release;
-
-       mrioc->bsg_queue = bsg_setup_queue(mrioc->bsg_dev, dev_name(mrioc->bsg_dev),
+       mrioc->bsg_queue = bsg_setup_queue(bsg_dev, dev_name(bsg_dev),
                        mpi3mr_bsg_request, NULL, 0);
        if (IS_ERR(mrioc->bsg_queue)) {
                ioc_err(mrioc, "%s: bsg registration failed\n",
-                   dev_name(mrioc->bsg_dev));
-               goto err_setup_queue;
+                   dev_name(bsg_dev));
+               device_del(bsg_dev);
+               put_device(bsg_dev);
+               return;
        }
 
        blk_queue_max_segments(mrioc->bsg_queue, MPI3MR_MAX_APP_XFER_SEGMENTS);
        blk_queue_max_hw_sectors(mrioc->bsg_queue, MPI3MR_MAX_APP_XFER_SECTORS);
 
        return;
-
-err_setup_queue:
-       device_del(mrioc->bsg_dev);
-       put_device(mrioc->bsg_dev);
-err_device_add:
-       kfree(mrioc->bsg_dev);
 }
 
 /**