Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 02/13] mm: bdi: fix race in bdi_class device creation | Date | Tue, 20 May 2008 15:34:49 -0700 |
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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> --- mm/backing-dev.c | 12 ++---------- 1 files changed, 2 insertions(+), 10 deletions(-)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 7c4f9e0..f2e574d 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); -- 1.5.5.1
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