Messages in this thread | | | Date | Thu, 9 Jan 2014 22:31:27 +0000 | From | Al Viro <> | Subject | Re: [PATCH] vfs: Fix possible NULL pointer dereference in inode_permission() |
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On Thu, Jan 09, 2014 at 04:50:12PM -0500, Steven Rostedt wrote:
> > We'd then have to get rid of all the call_rcu() invocations in individual > > filesystems' destroy_inode methods, but that doesn't sound like a bad > > thing to me.
Check what e.g. XFS is doing...
> Which is another reason that I didn't do it, as I didn't know all the > happenings inside the ->destroy_inode() calls. But yeah, I agree with > this. > > Also, can iput() sleep? If not then we are OK. Otherwise, we need to be > careful about any mutex being grabbed in those call backs, as the > rcu_callback can't sleep either.
iput() definitely can sleep (that's when actual truncation and inode freeing is done for opened-and-unlinked files - on the final iput() after close()), but that' irrelevant here - fsnotify_delete_inode() grabs a bunch of mutexes, which makes calling it from rcu callback no-go.
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