On Thu, Feb 5, 2015 at 8:57 PM, Peng Tao <tao.peng@xxxxxxxxxxxxxxx> wrote: > > On Fri, Feb 6, 2015 at 9:45 AM, Peng Tao <tao.peng@xxxxxxxxxxxxxxx> wrote: > > On Fri, Feb 6, 2015 at 6:37 AM, Trond Myklebust > > <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > >> If we have to do a return-on-close in the delegreturn code, then > >> we must ensure that the inode and super block remain referenced. > >> > ah, a second thought. I looked for call sites of nfs_sb_active() and > it gets called at five places in current tree: > alloc_nfs_open_context, nfs4_opendata_alloc, nfs4_do_close, > nfs_do_call_unlink, nfs_do_call_unlink > > So it appears that sb is activated while any file keeps opened and > between unlink calls. Then it looks that we are allowed to keep > delegations after sb is released? Maybe the best way to fix the sb > reference part is to pin sb when getting the first delegation. The superblock reference is only there in order to allow us to perform asynchronous delegreturns without any danger. The problem here is that we'd end up pinning the superblock even after umount if there are still unreturned delegations. That said, I do see that there is a problem with calling nfs_sb_active() when sb->s_active is zero, so I think I'd like to fix that up. -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
