| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.2 087/134] NFSv4.1: Fix a protocol issue with CLOSE stateids | Date | Sat, 26 Sep 2015 13:55:39 -0700 |
| |
4.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Trond Myklebust <trond.myklebust@primarydata.com>
commit 4a1e2feb9d246775dee0f78ed5b18826bae2b1c5 upstream.
According to RFC5661 Section 18.2.4, CLOSE is supposed to return the zero stateid. This means that nfs_clear_open_stateid_locked() cannot assume that the result stateid will always match the 'other' field of the existing open stateid when trying to determine a race with a parallel OPEN.
Instead, we look at the argument, and check for matches.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/nfs/nfs4proc.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
--- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1220,6 +1220,7 @@ static void nfs_resync_open_stateid_lock } static void nfs_clear_open_stateid_locked(struct nfs4_state *state, + nfs4_stateid *arg_stateid, nfs4_stateid *stateid, fmode_t fmode) { clear_bit(NFS_O_RDWR_STATE, &state->flags); @@ -1238,8 +1239,9 @@ static void nfs_clear_open_stateid_locke if (stateid == NULL) return; /* Handle races with OPEN */ - if (!nfs4_stateid_match_other(stateid, &state->open_stateid) || - !nfs4_stateid_is_newer(stateid, &state->open_stateid)) { + if (!nfs4_stateid_match_other(arg_stateid, &state->open_stateid) || + (nfs4_stateid_match_other(stateid, &state->open_stateid) && + !nfs4_stateid_is_newer(stateid, &state->open_stateid))) { nfs_resync_open_stateid_locked(state); return; } @@ -1248,10 +1250,12 @@ static void nfs_clear_open_stateid_locke nfs4_stateid_copy(&state->open_stateid, stateid); } -static void nfs_clear_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, fmode_t fmode) +static void nfs_clear_open_stateid(struct nfs4_state *state, + nfs4_stateid *arg_stateid, + nfs4_stateid *stateid, fmode_t fmode) { write_seqlock(&state->seqlock); - nfs_clear_open_stateid_locked(state, stateid, fmode); + nfs_clear_open_stateid_locked(state, arg_stateid, stateid, fmode); write_sequnlock(&state->seqlock); if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) nfs4_schedule_state_manager(state->owner->so_server->nfs_client); @@ -2684,7 +2688,8 @@ static void nfs4_close_done(struct rpc_t goto out_release; } } - nfs_clear_open_stateid(state, res_stateid, calldata->arg.fmode); + nfs_clear_open_stateid(state, &calldata->arg.stateid, + res_stateid, calldata->arg.fmode); out_release: nfs_release_seqid(calldata->arg.seqid); nfs_refresh_inode(calldata->inode, calldata->res.fattr);
|