Messages in this thread |  | | Date | Mon, 12 Nov 2018 17:56:27 -0800 | From | Matthew Wilcox <> | Subject | Re: [PATCH 01/12] kernfs: add function to find kernfs_node without increasing ref counter |
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On Mon, Nov 12, 2018 at 04:28:40AM -0800, Greg Kroah-Hartman wrote: > On Mon, Nov 12, 2018 at 10:56:21AM +0100, Paolo Valente wrote: > > From: Angelo Ruocco <angeloruocco90@gmail.com> > > > > The kernfs pseudo file system doesn't export any function to only find > > a node by name, without also getting a reference on it. > > But in some cases it is useful to just locate a kernfs node, while > > using it or not depends on some other condition. > > > > This commit adds a function to just look for a node, without getting > > a reference on it. > > Eeek, that sounds really bad. So you save off a pointer to something, > and have no idea if that pointer now really is valid or not? It can > instantly disappear right afterwards. > > This feels wrong, what is the problem of having a properly reference > counted object passed back to you that you have to create a dangerous > function like this?
I agree with Greg, this function is dangerous. What's wrong with using find_get and then doing a put once you successfully take it over, or fail to take it over?
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