Messages in this thread | | | Date | Thu, 5 Jan 2012 09:11:57 -0800 | From | Tejun Heo <> | Subject | Re: Revoking filesystems [was Re: Sysfs attributes racing with unregistration] |
| |
Hello,
On Thu, Jan 05, 2012 at 11:47:54AM -0500, Alan Stern wrote: > One problem (which was reported by a user last spring) is that > del_gendisk() calls device_del() for the disk and bdi_unregister() for > the disk's backing_dev_info structure. Now, del_gendisk will leave the > data structure in memory until the disk's refcount drops to 0, but > bdi_unregister ignores refcounts and simply erases the bdi->dev > pointer. Once this happens, any attempt to call mark_buffer_dirty() > (for example, by ext4_commit_super) will cause an oops.
Yeah, there were multiple bugs in block device hot-removal path. I got some of them fixed recently but didn't get to the bdi one yet. It's a bug and needs to be fixed regardless of fs revoke support.
Thanks.
-- tejun
| |