Messages in this thread | | | From | Miklos Szeredi <> | Date | Mon, 10 Aug 2020 10:29:13 +0200 | Subject | Re: [PATCH v2 18/20] fuse: Release file in process context |
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On Fri, Aug 7, 2020 at 9:55 PM Vivek Goyal <vgoyal@redhat.com> wrote: > > fuse_file_put(sync) can be called with sync=true/false. If sync=true, > it waits for release request response and then calls iput() in the > caller's context. If sync=false, it does not wait for release request > response, frees the fuse_file struct immediately and req->end function > does the iput(). > > iput() can be a problem with DAX if called in req->end context. If this > is last reference to inode (VFS has let go its reference already), then > iput() will clean DAX mappings as well and send REMOVEMAPPING requests > and wait for completion. (All the the worker thread context which is > processing fuse replies from daemon on the host). > > That means it blocks worker thread and it stops processing further > replies and system deadlocks.
Is this reasoning specific to DAX? Seems to me this is a virtio-fs specific issue.
Thanks, Miklos
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