From: Andy Adamson <andros@xxxxxxxxxx>
Prepare for the state manager thread to drain back channel.
Use the back channel highest_slot_used to indicate to the state manager
that a callback is being processed by the callback thread.
Fix the BADSLOT check - the first and only slotid is 0.
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
---
fs/nfs/callback_proc.c | 13 ++++++++++++-
fs/nfs/callback_xdr.c | 16 +++++++++++++++-
2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 6e21add..6ba528a 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -469,6 +469,9 @@ int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const n
* We have a single slot backchannel at this time, so we don't bother
* checking the used_slots bit array on the table. The lower layer guarantees
* a single outstanding callback request at a time.
+ *
+ * We set the highest slot used to let the state manager know when a
+ * callback is being processed and to wait until completion.
*/
static __be32
validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
@@ -478,10 +481,18 @@ validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
dprintk("%s enter. slotid %d seqid %d\n",
__func__, args->csa_slotid, args->csa_sequenceid);
- if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
+ /* Single slot, so slotid must be 0 */
+ if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS - 1 ||
+ args->csa_slotid < 0)
return htonl(NFS4ERR_BADSLOT);
+ spin_lock(&tbl->slot_tbl_lock);
slot = tbl->slots + args->csa_slotid;
+
+ /* Only a single slot */
+ tbl->highest_used_slotid = args->csa_slotid;
+ spin_unlock(&tbl->slot_tbl_lock);
+
dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
/* Normal */
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 695d15a..e05d1b3 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -773,8 +773,22 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r
*hdr_res.status = status;
*hdr_res.nops = htonl(nops);
- if (cps.session) /* matched by cb_sequence find_client_with_session */
+ if (cps.session) {
+ struct nfs4_slot_table *tbl = &cps.session->bc_slot_table;
+
+ spin_lock(&tbl->slot_tbl_lock);
+ /*
+ * Let the state manager know callback processing done.
+ * A single slot, so highest used slotid is either 0 or -1
+ */
+ tbl->highest_used_slotid--;
+ spin_unlock(&tbl->slot_tbl_lock);
+ dprintk("%s highest_used_slotid %d\n", __func__,
+ tbl->highest_used_slotid);
+
+ /* matched by cb_sequence find_client_with_session */
nfs_put_client(cps.session->clp);
+ }
dprintk("%s: done, status = %u\n", __func__, ntohl(status));
return rpc_success;
}
--
1.6.6
--
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