On 05/21/2010 11:55 PM, Jeff Layton wrote: > We've had a spate of "Busy inodes after umount" problems in recent > kernels. With the help of a reproducer that Suresh provided, I tracked > down the cause of one of these and wrote it up here: > > https://bugzilla.samba.org/show_bug.cgi?id=7433 > > The main problem is that CIFS opens files during create operations, > puts these files on a list and then expects that a subsequent open > operation will find those on the list and make them full, productive > members of society. > > This expectation is wrong however. There's no guarantee that cifs_open > will be called at all after a create. There are several scenarios that > can prevent it from occuring. When this happens, these entries get left > dangling on the list and nothing will ever clean them up. Recent changes > have made it so that cifsFileInfo structs hold an inode reference as > well, which is what actually leads to the busy inodes after umount > problems. > > This patch is intended to fix this in the right way. It has the create > operations properly use lookup_instantiate_filp to create an open file > during the operation that does the actual create. With this, there's > no need to have cifs_open scrape these entries off the list. I think this is how we should do it. This makes the code a lot cleaner and simpler to follow. > This fixes the busy inodes problem I was able to reproduce. It's not > very well tested yet however, and I could stand for someone else to > review it and help test it. > However, I still see "VFS: Busy inode" errors with my reproducer (with all patches except 1/4). Perhaps it has made the problem less frequent or it has got something to do with quick inode recyling. Nevertheless, I think this patchset is a good step in the right direction. Thanks, -- Suresh Jayaraman -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
