[PATCH 09/13] libnvdimm, pmem: use devm_add_action to release bdev resources

Dan Williams
2016-03-24T01:26:50Z

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>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/nvdimm/pmem.c | 88 ++++++++++++++++++++++---------------------------
1 file changed, 39 insertions(+), 49 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index ff336dd26064..97bc91b944b7 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -184,6 +184,17 @@ 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)
{
@@ -220,25 +231,22 @@ 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)
{
@@ -255,8 +263,10 @@ 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;
}

@@ -413,15 +423,6 @@ 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.
@@ -444,7 +445,6 @@ 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;
@@ -481,35 +481,33 @@ 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)
@@ -551,8 +549,8 @@ 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);
}

@@ -565,7 +563,6 @@ 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;
}

@@ -574,15 +571,8 @@ 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;
}