From 42acd021824578fa0eeb6eb58d457c23ec5dc9c0 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Thu, 6 Jan 2011 02:04:34 +0000 Subject: NFS add session back channel draining 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 Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 485e95e8fd6..6891dedd80f 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; @@ -165,22 +170,32 @@ 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) { int status; -- cgit v1.2.3-18-g5258