aboutsummaryrefslogtreecommitdiffstats
path: root/mm/backing-dev.c
diff options
context:
space:
mode:
authorGreg Kroah-Hartman <gregkh@suse.de>2008-05-15 16:44:08 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2008-05-20 16:31:53 -0400
commit19051c5035d217e572672a2ca9db06c1cef50e9b (patch)
tree9fef0047e070c977463a85d5cbd0f9479694d286 /mm/backing-dev.c
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>
Diffstat (limited to 'mm/backing-dev.c')
-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 7c4f9e097095..f2e574dbc300 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -172,30 +172,22 @@ postcore_initcall(bdi_class_init);
172int bdi_register(struct backing_dev_info *bdi, struct device *parent, 172int bdi_register(struct backing_dev_info *bdi, struct device *parent,
173 const char *fmt, ...) 173 const char *fmt, ...)
174{ 174{
175 char *name;
176 va_list args; 175 va_list args;
177 int ret = 0; 176 int ret = 0;
178 struct device *dev; 177 struct device *dev;
179 178
180 va_start(args, fmt); 179 va_start(args, fmt);
181 name = kvasprintf(GFP_KERNEL, fmt, args); 180 dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
182 va_end(args); 181 va_end(args);
183
184 if (!name)
185 return -ENOMEM;
186
187 dev = device_create(bdi_class, parent, MKDEV(0, 0), name);
188 if (IS_ERR(dev)) { 182 if (IS_ERR(dev)) {
189 ret = PTR_ERR(dev); 183 ret = PTR_ERR(dev);
190 goto exit; 184 goto exit;
191 } 185 }
192 186
193 bdi->dev = dev; 187 bdi->dev = dev;
194 dev_set_drvdata(bdi->dev, bdi); 188 bdi_debug_register(bdi, dev_name(dev));
195 bdi_debug_register(bdi, name);
196 189
197exit: 190exit:
198 kfree(name);
199 return ret; 191 return ret;
200} 192}
201EXPORT_SYMBOL(bdi_register); 193EXPORT_SYMBOL(bdi_register);