On Mon, Dec 6, 2010 at 10:19 PM, <andros@xxxxxxxxxx> wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> Currently session draining only drains the fore channel.
> The back channel processing must also be drained.
>
> Use the back channel highest_slot_used to indicate that a callback is being
> processed by the callback thread. Move the session complete to be per channel.
>
> When the session is draininig, wait for any current back channel processing
> to complete and stop all new back channel processing by returning NFS4ERR_DELAY
> to the back channel client.
>
> Drain the back channel, then the fore channel.
>
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfs/callback.h | 1 +
> fs/nfs/callback_proc.c | 6 ++++++
> fs/nfs/callback_xdr.c | 17 +++++++++++++++++
> fs/nfs/nfs4proc.c | 26 +++++++++++++++++++-------
> fs/nfs/nfs4state.c | 29 ++++++++++++++++++++++-------
> include/linux/nfs_fs_sb.h | 2 +-
> 6 files changed, 66 insertions(+), 15 deletions(-)
>
> diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
> index 85a7cfd..434233e 100644
> --- a/fs/nfs/callback.h
> +++ b/fs/nfs/callback.h
> @@ -131,6 +131,7 @@ extern unsigned nfs4_callback_recallslot(struct cb_recallslotargs *args,
>
> extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *res);
> extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy);
> +extern void nfs4_check_drain_bc_complete(struct nfs4_session *ses);
>
> #ifdef CONFIG_NFS_V4
> extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
> diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
> index 2950fca..7a976ef 100644
> --- a/fs/nfs/callback_proc.c
> +++ b/fs/nfs/callback_proc.c
> @@ -287,6 +287,12 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
> if (clp == NULL)
> goto out;
>
> + /* state manager is resetting the session */
> + if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
> + status = NFS4ERR_DELAY;
> + goto out_putclient;
> + }
> +
> status = validate_seqid(&clp->cl_session->bc_slot_table, args);
> if (status)
> goto out_putclient;
> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
> index 05af212..0a5e32d 100644
> --- a/fs/nfs/callback_xdr.c
> +++ b/fs/nfs/callback_xdr.c
> @@ -593,6 +593,20 @@ preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
> return htonl(NFS_OK);
> }
>
> +static void nfs4_callback_free_slot(struct nfs4_session *session)
Am I missing something, or was the call to this function omitted?
Fred
> +{
> + struct nfs4_slot_table *tbl = &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--;
> + nfs4_check_drain_bc_complete(session);
> + spin_unlock(&tbl->slot_tbl_lock);
> +}
> +
> #else /* CONFIG_NFS_V4_1 */
>
> static __be32
> @@ -601,6 +615,9 @@ preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
> return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
> }
>
> +static void nfs4_callback_free_slot(struct nfs4_session *session)
> +{
> +}
> #endif /* CONFIG_NFS_V4_1 */
>
> static __be32
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 6a653ff..b48f607 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -355,9 +355,9 @@ nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *free_slot)
> }
>
> /*
> - * Signal state manager thread if session is drained
> + * Signal state manager thread if session fore channel is drained
> */
> -static void nfs41_check_drain_session_complete(struct nfs4_session *ses)
> +static void nfs4_check_drain_fc_complete(struct nfs4_session *ses)
> {
> struct rpc_task *task;
>
> @@ -371,8 +371,20 @@ static void nfs41_check_drain_session_complete(struct nfs4_session *ses)
> if (ses->fc_slot_table.highest_used_slotid != -1)
> return;
>
> - dprintk("%s COMPLETE: Session Drained\n", __func__);
> - complete(&ses->complete);
> + dprintk("%s COMPLETE: Session Fore Channel Drained\n", __func__);
> + complete(&ses->fc_slot_table.complete);
> +}
> +
> +/*
> + * Signal state manager thread if session back channel is drained
> + */
> +void nfs4_check_drain_bc_complete(struct nfs4_session *ses)
> +{
> + if (!test_bit(NFS4_SESSION_DRAINING, &ses->session_state) ||
> + ses->bc_slot_table.highest_used_slotid != -1)
> + return;
> + dprintk("%s COMPLETE: Session Back Channel Drained\n", __func__);
> + complete(&ses->bc_slot_table.complete);
> }
>
> static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
> @@ -389,7 +401,7 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
>
> spin_lock(&tbl->slot_tbl_lock);
> nfs4_free_slot(tbl, res->sr_slot);
> - nfs41_check_drain_session_complete(res->sr_session);
> + nfs4_check_drain_fc_complete(res->sr_session);
> spin_unlock(&tbl->slot_tbl_lock);
> res->sr_slot = NULL;
> }
> @@ -4767,17 +4779,17 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
> if (!session)
> return NULL;
>
> - init_completion(&session->complete);
> -
> tbl = &session->fc_slot_table;
> tbl->highest_used_slotid = -1;
> spin_lock_init(&tbl->slot_tbl_lock);
> rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
> + init_completion(&tbl->complete);
>
> tbl = &session->bc_slot_table;
> tbl->highest_used_slotid = -1;
> spin_lock_init(&tbl->slot_tbl_lock);
> rpc_init_wait_queue(&tbl->slot_tbl_waitq, "BackChannel Slot table");
> + init_completion(&tbl->complete);
>
> session->session_state = 1<<NFS4_SESSION_INITING;
>
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index f575a31..0082483 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -142,6 +142,11 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
> return status;
> }
>
> +/*
> + * Back channel returns NFS4ERR_DELAY for new requests when
> + * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
> + * is ended.
> + */
> static void nfs4_end_drain_session(struct nfs_client *clp)
> {
> struct nfs4_session *ses = clp->cl_session;
> @@ -165,21 +170,31 @@ static void nfs4_end_drain_session(struct nfs_client *clp)
> }
> }
>
> -static int nfs4_begin_drain_session(struct nfs_client *clp)
> +static int nfs4_wait_on_slot_tbl(struct nfs4_slot_table *tbl)
> {
> - struct nfs4_session *ses = clp->cl_session;
> - struct nfs4_slot_table *tbl = &ses->fc_slot_table;
> -
> spin_lock(&tbl->slot_tbl_lock);
> - set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
> if (tbl->highest_used_slotid != -1) {
> - INIT_COMPLETION(ses->complete);
> + INIT_COMPLETION(tbl->complete);
> spin_unlock(&tbl->slot_tbl_lock);
> - return wait_for_completion_interruptible(&ses->complete);
> + return wait_for_completion_interruptible(&tbl->complete);
> }
> spin_unlock(&tbl->slot_tbl_lock);
> return 0;
> }
> +
> +static int nfs4_begin_drain_session(struct nfs_client *clp)
> +{
> + struct nfs4_session *ses = clp->cl_session;
> + int ret = 0;
> +
> + set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
> + /* back channel */
> + ret = nfs4_wait_on_slot_tbl(&ses->bc_slot_table);
> + if (ret)
> + return ret;
> + /* fore channel */
> + return nfs4_wait_on_slot_tbl(&ses->fc_slot_table);
> +}
>
> int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
> {
> diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
> index 452d964..8ded472 100644
> --- a/include/linux/nfs_fs_sb.h
> +++ b/include/linux/nfs_fs_sb.h
> @@ -196,6 +196,7 @@ struct nfs4_slot_table {
> * op for dynamic resizing */
> int target_max_slots; /* Set by CB_RECALL_SLOT as
> * the new max_slots */
> + struct completion complete;
> };
>
> static inline int slot_idx(struct nfs4_slot_table *tbl, struct nfs4_slot *sp)
> @@ -212,7 +213,6 @@ struct nfs4_session {
> unsigned long session_state;
> u32 hash_alg;
> u32 ssv_len;
> - struct completion complete;
>
> /* The fore and back channel */
> struct nfs4_channel_attrs fc_attrs;
> --
> 1.6.6
>
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