lkml.org 
[lkml]   [2017]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.12 188/196] device-dax: fix sysfs duplicate warnings
Date
4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams <dan.j.williams@intel.com>

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>
Reported-by: Dariusz Dokupil <dariusz.dokupil@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/dax/device-dax.h | 2 +-
drivers/dax/device.c | 24 ++++++++++++++++--------
drivers/dax/pmem.c | 12 +++++++-----
3 files changed, 24 insertions(+), 14 deletions(-)

--- a/drivers/dax/device-dax.h
+++ b/drivers/dax/device-dax.h
@@ -21,5 +21,5 @@ struct dax_region *alloc_dax_region(stru
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__ */
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -528,7 +528,8 @@ static void dev_dax_release(struct devic
struct dax_region *dax_region = dev_dax->region;
struct dax_device *dax_dev = dev_dax->dax_dev;

- ida_simple_remove(&dax_region->ida, dev_dax->id);
+ if (dev_dax->id >= 0)
+ ida_simple_remove(&dax_region->ida, dev_dax->id);
dax_region_put(dax_region);
put_dax(dax_dev);
kfree(dev_dax);
@@ -558,7 +559,7 @@ 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;
@@ -586,10 +587,16 @@ struct dev_dax *devm_create_dev_dax(stru
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;
- goto err_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;
}

/*
@@ -619,7 +626,7 @@ struct dev_dax *devm_create_dev_dax(stru
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) {
@@ -635,7 +642,8 @@ struct dev_dax *devm_create_dev_dax(stru
return dev_dax;

err_dax:
- ida_simple_remove(&dax_region->ida, dev_dax->id);
+ if (dev_dax->id >= 0)
+ ida_simple_remove(&dax_region->ida, dev_dax->id);
err_id:
kfree(dev_dax);

--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -58,13 +58,12 @@ static void dax_pmem_percpu_kill(void *d

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
/* 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);

\
 
 \ /
  Last update: 2017-07-25 21:27    [W:0.429 / U:0.660 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site