On Nov. 10, 2008, 22:21 +0200, Benny Halevy <bhalevy@xxxxxxxxxxx> wrote:
> 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 */
review 11-14: just limit to 128 bits, no dynamic allocation
> + 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;
> };
>
> /*
--
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