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>

1 files changed, 39 insertions, 49 deletions

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 2238e3af48ae..d936defdc1e2 100644
--- 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;
 }