Messages in this thread | | | Subject | Re: [PATCH v3 3/6] floppy: avoid leaking extra reference to queue on do_floppy_init error handling | From | Ben Hutchings <> | Date | Tue, 14 Aug 2012 15:28:07 +0100 |
| |
On Tue, 2012-08-14 at 11:03 +0200, Stanislaw Gruszka wrote: > On Tue, Aug 14, 2012 at 04:20:39AM +0100, Ben Hutchings wrote: > > On Mon, 2012-08-13 at 15:16 -0300, Herton Ronaldo Krzesinski wrote: > > > After commit 3f9a5aa ("floppy: Cleanup disk->queue before caling > > > put_disk() if add_disk() was never called"), if something fails in the > > > add_disk loop, we unconditionally set disks[dr]->queue to NULL. But > > > that's wrong, since we may have succesfully done an add_disk on some of > > > the drives previously in the loop, and in this case we would end up with > > > an extra reference to the disks[dr]->queue. > > > > > > Add a new global array to mark "registered" disks, and use that to check > > > if we did an add_disk on one of the disks already. Using an array to > > > track added disks also will help to simplify/cleanup code later, as > > > suggested by Vivek Goyal. > > [...] > > > > It's totally ridiculous that a driver should have to do this. Any > > registered disk should have the GENHD_FL_UP flag set... so why can't > > genhd check it? It doesn't look like floppy is the only driver affected > > by this problem, either. So I suggest the following general fix > > (untested): > > > > --- > > Subject: genhd: Make put_disk() safe for disks that have not been registered > > > > Since commit 9f53d2f ('block: fix __blkdev_get and add_disk race > > condition'), add_disk() adds a reference to disk->queue, > > I do not see this? Commit 9f53d2fe insert disk_alloc_events() to add_disk(), > but disk_alloc_events() function does not get any reference to disk->queue, > I missed something?
Sorry, not sure why I pointed to that one. The reference should of course be to:
commit 523e1d399ce0e23bec562abe2b2f8d297af81161 Author: Tejun Heo <tj@kernel.org> Date: Wed Oct 19 14:31:07 2011 +0200
block: make gendisk hold a reference to its queue
Ben.
-- Ben Hutchings I say we take off; nuke the site from orbit. It's the only way to be sure. [unhandled content-type:application/pgp-signature] | |