libnvdimm, pmem: use devm_add_action to release bdev resources

Register a callback to clean up the request_queue and put the gendisk at
driver disable time.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 2238e3a..d936def 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -198,6 +198,17 @@ static const struct block_device_operations pmem_fops = {
        .revalidate_disk =      nvdimm_revalidate_disk,
 };
 
+static void pmem_release_queue(void *q)
+{
+       blk_cleanup_queue(q);
+}
+
+void pmem_release_disk(void *disk)
+{
+       del_gendisk(disk);
+       put_disk(disk);
+}
+
 static struct pmem_device *pmem_alloc(struct device *dev,
                struct resource *res, int id)
 {
@@ -234,25 +245,22 @@ static struct pmem_device *pmem_alloc(struct device *dev,
                                pmem->phys_addr, pmem->size,
                                ARCH_MEMREMAP_PMEM);
 
-       if (IS_ERR(pmem->virt_addr)) {
+       /*
+        * At release time the queue must be dead before
+        * devm_memremap_pages is unwound
+        */
+       if (devm_add_action(dev, pmem_release_queue, q)) {
                blk_cleanup_queue(q);
-               return (void __force *) pmem->virt_addr;
+               return ERR_PTR(-ENOMEM);
        }
 
+       if (IS_ERR(pmem->virt_addr))
+               return (void __force *) pmem->virt_addr;
+
        pmem->pmem_queue = q;
        return pmem;
 }
 
-static void pmem_detach_disk(struct pmem_device *pmem)
-{
-       if (!pmem->pmem_disk)
-               return;
-
-       del_gendisk(pmem->pmem_disk);
-       put_disk(pmem->pmem_disk);
-       blk_cleanup_queue(pmem->pmem_queue);
-}
-
 static int pmem_attach_disk(struct device *dev,
                struct nd_namespace_common *ndns, struct pmem_device *pmem)
 {
@@ -269,8 +277,10 @@ static int pmem_attach_disk(struct device *dev,
        pmem->pmem_queue->queuedata = pmem;
 
        disk = alloc_disk_node(0, nid);
-       if (!disk) {
-               blk_cleanup_queue(pmem->pmem_queue);
+       if (!disk)
+               return -ENOMEM;
+       if (devm_add_action(dev, pmem_release_disk, disk)) {
+               put_disk(disk);
                return -ENOMEM;
        }
 
@@ -427,15 +437,6 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
        return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
 }
 
-static void nvdimm_namespace_detach_pfn(struct nd_pfn *nd_pfn)
-{
-       struct pmem_device *pmem;
-
-       /* free pmem disk */
-       pmem = dev_get_drvdata(&nd_pfn->dev);
-       pmem_detach_disk(pmem);
-}
-
 /*
  * We hotplug memory at section granularity, pad the reserved area from
  * the previous section base to the namespace base address.
@@ -458,7 +459,6 @@ static unsigned long init_altmap_reserve(resource_size_t base)
 
 static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 {
-       int rc;
        struct resource res;
        struct request_queue *q;
        struct pmem_device *pmem;
@@ -495,35 +495,33 @@ static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
                altmap = & __altmap;
                altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
                altmap->alloc = 0;
-       } else {
-               rc = -ENXIO;
-               goto err;
-       }
+       } else
+               return -ENXIO;
 
        /* establish pfn range for lookup, and switch to direct map */
        q = pmem->pmem_queue;
        memcpy(&res, &nsio->res, sizeof(res));
        res.start += start_pad;
        res.end -= end_trunc;
+       devm_remove_action(dev, pmem_release_queue, q);
        devm_memunmap(dev, (void __force *) pmem->virt_addr);
        pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
                        &q->q_usage_counter, altmap);
        pmem->pfn_flags |= PFN_MAP;
-       if (IS_ERR(pmem->virt_addr)) {
-               rc = PTR_ERR(pmem->virt_addr);
-               goto err;
+
+       /*
+        * At release time the queue must be dead before
+        * devm_memremap_pages is unwound
+        */
+       if (devm_add_action(dev, pmem_release_queue, q)) {
+               blk_cleanup_queue(q);
+               return -ENOMEM;
        }
+       if (IS_ERR(pmem->virt_addr))
+               return PTR_ERR(pmem->virt_addr);
 
        /* attach pmem disk in "pfn-mode" */
-       rc = pmem_attach_disk(dev, ndns, pmem);
-       if (rc)
-               goto err;
-
-       return rc;
- err:
-       nvdimm_namespace_detach_pfn(nd_pfn);
-       return rc;
-
+       return pmem_attach_disk(dev, ndns, pmem);
 }
 
 static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
@@ -565,8 +563,8 @@ static int nd_pmem_probe(struct device *dev)
 
        if (is_nd_btt(dev)) {
                /* btt allocates its own request_queue */
+               devm_remove_action(dev, pmem_release_queue, pmem->pmem_queue);
                blk_cleanup_queue(pmem->pmem_queue);
-               pmem->pmem_queue = NULL;
                return nvdimm_namespace_attach_btt(ndns);
        }
 
@@ -579,7 +577,6 @@ static int nd_pmem_probe(struct device *dev)
                 * We'll come back as either btt-pmem, or pfn-pmem, so
                 * drop the queue allocation for now.
                 */
-               blk_cleanup_queue(pmem->pmem_queue);
                return -ENXIO;
        }
 
@@ -588,15 +585,8 @@ static int nd_pmem_probe(struct device *dev)
 
 static int nd_pmem_remove(struct device *dev)
 {
-       struct pmem_device *pmem = dev_get_drvdata(dev);
-
        if (is_nd_btt(dev))
                nvdimm_namespace_detach_btt(to_nd_btt(dev));
-       else if (is_nd_pfn(dev))
-               nvdimm_namespace_detach_pfn(to_nd_pfn(dev));
-       else
-               pmem_detach_disk(pmem);
-
        return 0;
 }