NFSv4.x: Allow multiple callbacks in flight
Hook the callback channel into the same session management machinery
as we use for the forward channel.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
index e23366e..332d06e 100644
--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -135,6 +135,43 @@
return ERR_PTR(-ENOMEM);
}
+static void nfs4_lock_slot(struct nfs4_slot_table *tbl,
+ struct nfs4_slot *slot)
+{
+ u32 slotid = slot->slot_nr;
+
+ __set_bit(slotid, tbl->used_slots);
+ if (slotid > tbl->highest_used_slotid ||
+ tbl->highest_used_slotid == NFS4_NO_SLOT)
+ tbl->highest_used_slotid = slotid;
+ slot->generation = tbl->generation;
+}
+
+/*
+ * nfs4_try_to_lock_slot - Given a slot try to allocate it
+ *
+ * Note: must be called with the slot_tbl_lock held.
+ */
+bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
+{
+ if (nfs4_test_locked_slot(tbl, slot->slot_nr))
+ return false;
+ nfs4_lock_slot(tbl, slot);
+ return true;
+}
+
+/*
+ * nfs4_lookup_slot - Find a slot but don't allocate it
+ *
+ * Note: must be called with the slot_tbl_lock held.
+ */
+struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid)
+{
+ if (slotid <= tbl->max_slotid)
+ return nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
+ return ERR_PTR(-E2BIG);
+}
+
/*
* nfs4_alloc_slot - efficiently look for a free slot
*
@@ -153,18 +190,11 @@
__func__, tbl->used_slots[0], tbl->highest_used_slotid,
tbl->max_slotid + 1);
slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
- if (slotid > tbl->max_slotid)
- goto out;
- ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
- if (IS_ERR(ret))
- goto out;
- __set_bit(slotid, tbl->used_slots);
- if (slotid > tbl->highest_used_slotid ||
- tbl->highest_used_slotid == NFS4_NO_SLOT)
- tbl->highest_used_slotid = slotid;
- ret->generation = tbl->generation;
-
-out:
+ if (slotid <= tbl->max_slotid) {
+ ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
+ if (!IS_ERR(ret))
+ nfs4_lock_slot(tbl, ret);
+ }
dprintk("<-- %s used_slots=%04lx highest_used=%u slotid=%u\n",
__func__, tbl->used_slots[0], tbl->highest_used_slotid,
!IS_ERR(ret) ? ret->slot_nr : NFS4_NO_SLOT);