4.18-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
commit 21a446cf186570168b7281b154b1993968598aca upstream.
If we exit the NFSv4 state manager due to a umount, then we can end up leaving the NFS4CLNT_MANAGER_RUNNING flag set. If another mount causes the nfs4_client to be rereferenced before it is destroyed, then we end up never being able to recover state.
Fixes: 47c2199b6eb5 ("NFSv4.1: Ensure state manager thread dies on last ...") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/nfs/nfs4state.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -2553,11 +2553,12 @@ static void nfs4_state_manager(struct nf nfs4_clear_state_manager_bit(clp); /* Did we race with an attempt to give us more work? */ if (clp->cl_state == 0) - break; + return; if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) - break; + return; } while (refcount_read(&clp->cl_count) > 1); - return; + goto out_drain; + out_error: if (strlen(section)) section_sep = ": "; @@ -2565,6 +2566,7 @@ out_error: " with error %d\n", section_sep, section, clp->cl_hostname, -status); ssleep(1); +out_drain: nfs4_end_drain_session(clp); nfs4_clear_state_manager_bit(clp); }