diff mbox

[4.9-stable] device-dax: fix sysfs duplicate warnings

Message ID 150180630236.6719.1152880381080551797.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dan Williams Aug. 4, 2017, 12:25 a.m. UTC
commit bbb3be170ac2891526ad07b18af7db226879a8e7 upstream.

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: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem...")
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Dariusz Dokupil <dariusz.dokupil@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/dax.c  |   24 ++++++++++++++++--------
 drivers/dax/dax.h  |    2 +-
 drivers/dax/pmem.c |   12 +++++++-----
 3 files changed, 24 insertions(+), 14 deletions(-)

Comments

Greg KH Aug. 4, 2017, 8:01 p.m. UTC | #1
On Thu, Aug 03, 2017 at 05:25:02PM -0700, Dan Williams wrote:
> commit bbb3be170ac2891526ad07b18af7db226879a8e7 upstream.
> 
> 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: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem...")
> Cc: Jeff Moyer <jmoyer@redhat.com>
> Cc: <stable@vger.kernel.org>
> Reported-by: Dariusz Dokupil <dariusz.dokupil@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/dax/dax.c  |   24 ++++++++++++++++--------
>  drivers/dax/dax.h  |    2 +-
>  drivers/dax/pmem.c |   12 +++++++-----
>  3 files changed, 24 insertions(+), 14 deletions(-)

Thanks for the backport, now applied.

greg k-h
diff mbox

Patch

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 586f9543de73..40be3747724d 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -546,7 +546,8 @@  static void dax_dev_release(struct device *dev)
 	struct dax_dev *dax_dev = to_dax_dev(dev);
 	struct dax_region *dax_region = dax_dev->region;
 
-	ida_simple_remove(&dax_region->ida, dax_dev->id);
+	if (dax_dev->id >= 0)
+		ida_simple_remove(&dax_region->ida, dax_dev->id);
 	ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
 	dax_region_put(dax_region);
 	iput(dax_dev->inode);
@@ -581,7 +582,7 @@  static void unregister_dax_dev(void *dev)
 }
 
 struct dax_dev *devm_create_dax_dev(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_dev *dax_dev;
@@ -608,10 +609,16 @@  struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
 	if (i < count)
 		goto err_id;
 
-	dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
-	if (dax_dev->id < 0) {
-		rc = dax_dev->id;
-		goto err_id;
+	if (id < 0) {
+		id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
+		dax_dev->id = id;
+		if (id < 0) {
+			rc = id;
+			goto err_id;
+		}
+	} else {
+		/* region provider owns @id lifetime */
+		dax_dev->id = -1;
 	}
 
 	minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
@@ -650,7 +657,7 @@  struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
 	dev->parent = parent;
 	dev->groups = dax_attribute_groups;
 	dev->release = dax_dev_release;
-	dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id);
+	dev_set_name(dev, "dax%d.%d", dax_region->id, id);
 	rc = device_add(dev);
 	if (rc) {
 		kill_dax_dev(dax_dev);
@@ -669,7 +676,8 @@  struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
  err_inode:
 	ida_simple_remove(&dax_minor_ida, minor);
  err_minor:
-	ida_simple_remove(&dax_region->ida, dax_dev->id);
+	if (dax_dev->id >= 0)
+		ida_simple_remove(&dax_region->ida, dax_dev->id);
  err_id:
 	kfree(dax_dev);
 
diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h
index ddd829ab58c0..b5ed85036b2a 100644
--- a/drivers/dax/dax.h
+++ b/drivers/dax/dax.h
@@ -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 dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
-		struct resource *res, int count);
+		int id, struct resource *res, int count);
 #endif /* __DAX_H__ */
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index 73c6ce93a0d9..eebb35720398 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -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;
 	struct dax_dev *dax_dev;
+	int rc, id, region_id;
 	struct nd_pfn_sb *pfn_sb;
 	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;
@@ -122,14 +121,17 @@  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... */
-	dax_dev = devm_create_dax_dev(dax_region, &res, 1);
+	dax_dev = devm_create_dax_dev(dax_region, id, &res, 1);
 
 	/* child dax_dev instances now own the lifetime of the dax_region */
 	dax_region_put(dax_region);