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authorGreg Kroah-Hartman <gregkh@suse.de>2008-05-15 13:44:08 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2008-05-20 13:31:53 -0700
commit19051c5035d217e572672a2ca9db06c1cef50e9b (patch)
tree9fef0047e070c977463a85d5cbd0f9479694d286
parent8882b39421bae317e3ee864edd845e994307ce16 (diff)
mm: bdi: fix race in bdi_class device creation
There is a race from when a device is created with device_create() and then the drvdata is set with a call to dev_set_drvdata() in which a sysfs file could be open, yet the drvdata will be NULL, causing all sorts of bad things to happen. This patch fixes the problem by using the new function, device_create_vargs(). Many thanks to Arthur Jones <ajones@riverbed.com> for reporting the bug, and testing patches out. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Arthur Jones <ajones@riverbed.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--mm/backing-dev.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 7c4f9e09709..f2e574dbc30 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -172,30 +172,22 @@ postcore_initcall(bdi_class_init);
int bdi_register(struct backing_dev_info *bdi, struct device *parent,
const char *fmt, ...)
{
- char *name;
va_list args;
int ret = 0;
struct device *dev;
va_start(args, fmt);
- name = kvasprintf(GFP_KERNEL, fmt, args);
+ dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
va_end(args);
-
- if (!name)
- return -ENOMEM;
-
- dev = device_create(bdi_class, parent, MKDEV(0, 0), name);
if (IS_ERR(dev)) {
ret = PTR_ERR(dev);
goto exit;
}
bdi->dev = dev;
- dev_set_drvdata(bdi->dev, bdi);
- bdi_debug_register(bdi, name);
+ bdi_debug_register(bdi, dev_name(dev));
exit:
- kfree(name);
return ret;
}
EXPORT_SYMBOL(bdi_register);