Code to initialize and destroy the slot table.
Uses bitmap-based allocation.
Signed-off-by: Andy Adamson<andros@xxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 88 ++++++++++++++++++++++++++++++++++++++++++
include/linux/nfs4_session.h | 17 ++++++++
2 files changed, 105 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d0b6ca1..08e7129 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3683,6 +3683,92 @@ int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name,
}
#ifdef CONFIG_NFS_V4_1
+/*
+ * Initialize slot table
+ *
+ * Note: the "used" bitmap points to _used_slots id max_slots <= BITS_PER_LONG.
+ * Otherwise, we dynamically allocate enough ulongs to hold max_slots bits.
+ */
+static int nfs4_init_slot_table(struct nfs4_channel *channel)
+{
+ struct nfs4_slot_table *tbl = &channel->slot_table;
+ int i, max_slots = channel->chan_attrs.max_reqs;
+ struct nfs4_slot *slot;
+ unsigned long *used;
+ int ret = -ENOMEM;
+
+ dprintk("--> %s: max_reqs=%u\n", __func__,
+ channel->chan_attrs.max_reqs);
+ slot = kzalloc(max_slots * sizeof(struct nfs4_slot), GFP_ATOMIC);
+ if (!slot)
+ goto out;
+ for (i = 0; i < max_slots; ++i)
+ slot[i].seq_nr = 1;
+
+ if (max_slots <= BITS_PER_LONG)
+ used = &tbl->_used_slots; /* use word in tbl */
+ else {
+ /* allocate enough unsigned longs for max_slots bits */
+ used = kzalloc(sizeof(unsigned long) *
+ DIV_ROUND_UP(max_slots, BITS_PER_LONG),
+ GFP_ATOMIC);
+ if (!used)
+ goto out_free;
+ }
+ ret = 0;
+
+ spin_lock(&tbl->slot_tbl_lock);
+ if (tbl->slots != NULL) {
+ spin_unlock(&tbl->slot_tbl_lock);
+ dprintk("%s: slot table already initialized. tbl=%p slots=%p\n",
+ __func__, tbl, tbl->slots);
+ WARN_ON(1);
+ goto out_free;
+ }
+ tbl->max_slots = max_slots;
+ tbl->slots = slot;
+ tbl->used_slots = used;
+ tbl->lowest_free_slotid = 0; /* first slot is free */
+ tbl->highest_used_slotid = -1; /* no slot is currently used */
+ spin_unlock(&tbl->slot_tbl_lock);
+ dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,
+ tbl, tbl->slots, tbl->max_slots);
+out:
+ dprintk("<-- %s: return %d\n", __func__, ret);
+ return ret;
+out_free:
+ kfree(slot);
+ if (used != &tbl->_used_slots)
+ kfree(used);
+ goto out;
+}
+
+/* Destroy the slot table */
+static void nfs4_destroy_slot_table(struct nfs4_channel *channel)
+{
+ if (channel->slot_table.slots == NULL)
+ return;
+ kfree(channel->slot_table.slots);
+ channel->slot_table.slots = NULL;
+ /* Was the "used" bitmap dynamically allocated? */
+ if (channel->slot_table.used_slots != &channel->slot_table._used_slots)
+ kfree(channel->slot_table.used_slots);
+
+ return;
+}
+
+static int nfs4_init_channel(struct nfs4_channel *channel)
+{
+ struct nfs4_slot_table *tbl;
+
+ tbl = &channel->slot_table;
+
+ spin_lock_init(&tbl->slot_tbl_lock);
+ rpc_init_wait_queue(&tbl->slot_tbl_waitq, "Slot table");
+
+ return 0;
+}
+
struct nfs4_session *nfs4_alloc_session(void)
{
struct nfs4_session *session;
@@ -3693,6 +3779,7 @@ struct nfs4_session *nfs4_alloc_session(void)
atomic_set(&session->ref_count, 1);
+ nfs4_init_channel(&session->fore_channel);
return session;
}
@@ -3706,6 +3793,7 @@ void nfs4_put_session(struct nfs4_session **session)
{
dprintk("--> nfs4_put_session()\n");
if (atomic_dec_and_test(&((*session)->ref_count))) {
+ nfs4_destroy_slot_table(&((*session)->fore_channel));
nfs4_free_session(*session);
*session = NULL;
}
diff --git a/include/linux/nfs4_session.h b/include/linux/nfs4_session.h
index 36c0f94..d534269 100644
--- a/include/linux/nfs4_session.h
+++ b/include/linux/nfs4_session.h
@@ -17,9 +17,26 @@ struct nfs4_channel_attrs {
u32 rdma_attrs;
};
+struct nfs4_slot {
+ u32 seq_nr;
+};
+
+struct nfs4_slot_table {
+ struct nfs4_slot *slots; /* seqid per slot */
+ unsigned long *used_slots; /* used/unused bitmap */
+ unsigned long _used_slots; /* used when max_slots fits */
+ spinlock_t slot_tbl_lock;
+ struct rpc_wait_queue slot_tbl_waitq; /* allocators may wait here */
+ int max_slots; /* # slots in table */
+ int lowest_free_slotid; /* lower bound hint */
+ int highest_used_slotid; /* sent to server on each SEQ.
+ * op for dynamic resizing */
+};
+
struct nfs4_channel {
struct nfs4_channel_attrs chan_attrs;
struct rpc_clnt *rpc_client;
+ struct nfs4_slot_table slot_table;
};
/*
--
1.6.0.2
--
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