Commit bbb3be17 authored by Dan Williams's avatar Dan Williams
Browse files

device-dax: fix sysfs duplicate warnings 

Fix warnings of the form...

     WARNING: CPU: 10 PID: 4983 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
     sysfs: cannot create duplicate filename '/class/dax/dax12.0'
     Call Trace:
      dump_stack+0x63/0x86
      __warn+0xcb/0xf0
      warn_slowpath_fmt+0x5a/0x80
      ? kernfs_path_from_node+0x4f/0x60
      sysfs_warn_dup+0x62/0x80
      sysfs_do_create_link_sd.isra.2+0x97/0xb0
      sysfs_create_link+0x25/0x40
      device_add+0x266/0x630
      devm_create_dax_dev+0x2cf/0x340 [dax]
      dax_pmem_probe+0x1f5/0x26e [dax_pmem]
      nvdimm_bus_probe+0x71/0x120

...by reusing the namespace id for the device-dax instance name.

Now that we have decided that there will never by more than one
device-dax instance per libnvdimm-namespace parent device [1], we can
directly reuse the namepace ids. There are some possible follow-on
cleanups, but those are saved for a later patch to simplify the -stable
backport.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2016-December/008266.html



Fixes: 98a29c39 ("libnvdimm, namespace: allow creation of multiple pmem...")
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: default avatarDariusz Dokupil <dariusz.dokupil@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 23b9babb

drivers/dax/device-dax.h

+1 −1
Original line number Diff line number Diff line
@@ -21,5 +21,5 @@ struct dax_region *alloc_dax_region(struct device *parent, 
		int region_id, struct resource *res, unsigned int align,

		void *addr, unsigned long flags);

struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,

		struct resource *res, int count);

		int id, struct resource *res, int count);

#endif /* __DEVICE_DAX_H__ */

drivers/dax/device.c

+16 −8
Original line number Diff line number Diff line
@@ -529,6 +529,7 @@ static void dev_dax_release(struct device *dev) 
	struct dax_region *dax_region = dev_dax->region;

	struct dax_device *dax_dev = dev_dax->dax_dev;



	if (dev_dax->id >= 0)

		ida_simple_remove(&dax_region->ida, dev_dax->id);

	dax_region_put(dax_region);

	put_dax(dax_dev);
@@ -559,7 +560,7 @@ static void unregister_dev_dax(void *dev) 
}



struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,

		struct resource *res, int count)

		int id, struct resource *res, int count)

{

	struct device *parent = dax_region->dev;

	struct dax_device *dax_dev;
@@ -590,11 +591,17 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, 
	if (i < count)

		goto err_id;



	dev_dax->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);

	if (dev_dax->id < 0) {

		rc = dev_dax->id;

	if (id < 0) {

		id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);

		dev_dax->id = id;

		if (id < 0) {

			rc = id;

			goto err_id;

		}

	} else {

		/* region provider owns @id lifetime */

		dev_dax->id = -1;

	}



	/*

	 * No 'host' or dax_operations since there is no access to this
@@ -625,7 +632,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, 
	dev->parent = parent;

	dev->groups = dax_attribute_groups;

	dev->release = dev_dax_release;

	dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);

	dev_set_name(dev, "dax%d.%d", dax_region->id, id);



	rc = cdev_device_add(cdev, dev);

	if (rc) {
@@ -641,6 +648,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, 
	return dev_dax;



 err_dax:

	if (dev_dax->id >= 0)

		ida_simple_remove(&dax_region->ida, dev_dax->id);

 err_id:

	kfree(dev_dax);

drivers/dax/pmem.c

+7 −5
Original line number Diff line number Diff line
@@ -58,13 +58,12 @@ static void dax_pmem_percpu_kill(void *data) 


static int dax_pmem_probe(struct device *dev)

{

	int rc;

	void *addr;

	struct resource res;

	int rc, id, region_id;

	struct nd_pfn_sb *pfn_sb;

	struct dev_dax *dev_dax;

	struct dax_pmem *dax_pmem;

	struct nd_region *nd_region;

	struct nd_namespace_io *nsio;

	struct dax_region *dax_region;

	struct nd_namespace_common *ndns;
@@ -123,14 +122,17 @@ static int dax_pmem_probe(struct device *dev) 
	/* adjust the dax_region resource to the start of data */

	res.start += le64_to_cpu(pfn_sb->dataoff);



	nd_region = to_nd_region(dev->parent);

	dax_region = alloc_dax_region(dev, nd_region->id, &res,

	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);

	if (rc != 2)

		return -EINVAL;



	dax_region = alloc_dax_region(dev, region_id, &res,

			le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP);

	if (!dax_region)

		return -ENOMEM;



	/* TODO: support for subdividing a dax region... */

	dev_dax = devm_create_dev_dax(dax_region, &res, 1);

	dev_dax = devm_create_dev_dax(dax_region, id, &res, 1);



	/* child dev_dax instances now own the lifetime of the dax_region */

	dax_region_put(dax_region);

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