Messages in this thread | | | Date | Wed, 1 Dec 2010 15:36:08 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v2 3/3] NFS: Fix a memory leak in nfs_readdir |
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On Wed, 1 Dec 2010 15:31:11 -0800 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Wed, Dec 1, 2010 at 2:38 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > > > > OK, the stop_machine() plugs a lot of potential race-vs-module-unload > > things. __But Trond is referring to races against vmscan inode reclaim, > > unmount, etc. > > So? > > A filesystem module cannot be unloaded while it's still mounted. > > And unmount doesn't succeed until all inodes are gone. > > And getting rid of an inode doesn't succeed until all pages associated > with it are gone. > > And getting rid of the pages involves locking them (whether in > truncate or vmscan) and removing them from all lists. > > Ergo: vmscan has a locked page leads to the filesystem being > guaranteed to not be unmounted. And that, in turn, guarantees that > the module won't be unloaded until the machine has gone through an > idle cycle.
The page isn't attached to the address_space any more:
static int __remove_mapping(struct address_space *mapping, struct page *page) { ... __remove_from_page_cache(page); spin_unlock_irq(&mapping->tree_lock); ... }
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