The logic was becoming difficult to follow. Add some comments and local
variables to clarify the behavior.
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 39 +++++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 14 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 9ced7a62c05e..499f978d48aa 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1568,23 +1568,34 @@ static void nfs_test_and_clear_all_open_stateid(struct nfs4_state *state)
static bool nfs_need_update_open_stateid(struct nfs4_state *state,
const nfs4_stateid *stateid)
{
- if (test_bit(NFS_OPEN_STATE, &state->flags) == 0 ||
- !nfs4_stateid_match_other(stateid, &state->open_stateid)) {
- if (stateid->seqid == cpu_to_be32(1)) {
+ bool state_matches_other = nfs4_stateid_match_other(stateid, &state->open_stateid);
+ bool seqid_one = stateid->seqid == cpu_to_be32(1);
+
+ if (test_bit(NFS_OPEN_STATE, &state->flags)) {
+ /* The common case - we're updating to a new sequence number */
+ if (state_matches_other && nfs4_stateid_is_newer(stateid, &state->open_stateid)) {
+ nfs_state_log_out_of_order_open_stateid(state, stateid);
+ return true;
+ }
+ /* We lost a race with a self-bumping close, do recovery */
+ if (!state_matches_other) {
+ trace_printk("lost race to self-bump close\n");
+ return false;
+ }
+ } else {
+ /* The common case, this is the first OPEN */
+ if (!state_matches_other && seqid_one) {
nfs_state_log_update_open_stateid(state);
- } else {
- if (!nfs4_stateid_match_other(stateid, &state->open_stateid))
- return false;
- else
- set_bit(NFS_STATE_CHANGE_WAIT, &state->flags);
+ return true;
+ }
+ /* We lost a race either with a self-bumping close, OR with the first OPEN */
+ if (!state_matches_other && !seqid_one) {
+ trace_printk("lost race to self-bump close OR first OPEN\n");
+ set_bit(NFS_STATE_CHANGE_WAIT, &state->flags);
+ return true;
}
- return true;
- }
-
- if (nfs4_stateid_is_newer(stateid, &state->open_stateid)) {
- nfs_state_log_out_of_order_open_stateid(state, stateid);
- return true;
}
+ /* Should be impossible to reach: */
return false;
}
--
2.20.1
