diff options
author | Andy Adamson <andros@netapp.com> | 2009-12-04 15:55:38 -0500 |
---|---|---|
committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2009-12-04 15:55:38 -0500 |
commit | ea028ac92541ac30bf202ed94cb53eec2ea0c9d6 (patch) | |
tree | f9b807cf0f870db922f96e72dab68ed37ba18cf0 /fs/nfs/nfs4proc.c | |
parent | 05f0d2364726c92f6b870db654967088349379fe (diff) | |
download | linux-3.10-ea028ac92541ac30bf202ed94cb53eec2ea0c9d6.tar.gz linux-3.10-ea028ac92541ac30bf202ed94cb53eec2ea0c9d6.tar.bz2 linux-3.10-ea028ac92541ac30bf202ed94cb53eec2ea0c9d6.zip |
nfs41: nfs41: fix state manager deadlock in session reset
If the session is reset during state recovery, the state manager thread can
sleep on the slot_tbl_waitq causing a deadlock.
Add a completion framework to the session. Have the state manager thread set
a new session state (NFS4CLNT_SESSION_DRAINING) and wait for the session slot
table to drain.
Signal the state manager thread in nfs41_sequence_free_slot when the
NFS4CLNT_SESSION_DRAINING bit is set and the session is drained.
Reported-by: Trond Myklebust <trond@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4proc.c')
-rw-r--r-- | fs/nfs/nfs4proc.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index fb62919f7f2..c1bc9cad5e8 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -361,6 +361,16 @@ void nfs41_sequence_free_slot(const struct nfs_client *clp, } nfs4_free_slot(tbl, res->sr_slotid); res->sr_slotid = NFS4_MAX_SLOT_TABLE; + + /* Signal state manager thread if session is drained */ + if (test_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) { + spin_lock(&tbl->slot_tbl_lock); + if (tbl->highest_used_slotid == -1) { + dprintk("%s COMPLETE: Session Drained\n", __func__); + complete(&clp->cl_session->complete); + } + spin_unlock(&tbl->slot_tbl_lock); + } } static void nfs41_sequence_done(struct nfs_client *clp, @@ -457,15 +467,11 @@ static int nfs41_setup_sequence(struct nfs4_session *session, spin_lock(&tbl->slot_tbl_lock); if (test_bit(NFS4CLNT_SESSION_RESET, &session->clp->cl_state)) { - if (tbl->highest_used_slotid != -1) { - rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); - spin_unlock(&tbl->slot_tbl_lock); - dprintk("<-- %s: Session reset: draining\n", __func__); - return -EAGAIN; - } - - /* The slot table is empty; start the reset thread */ - dprintk("%s Session Reset\n", __func__); + /* + * The state manager will wait until the slot table is empty. + * Schedule the reset thread + */ + dprintk("%s Schedule Session Reset\n", __func__); rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); nfs4_schedule_state_manager(session->clp); spin_unlock(&tbl->slot_tbl_lock); @@ -4506,6 +4512,7 @@ static int nfs4_reset_slot_tables(struct nfs4_session *session) 1); if (status) return status; + init_completion(&session->complete); status = nfs4_reset_slot_table(&session->bc_slot_table, session->bc_attrs.max_reqs, @@ -4608,6 +4615,7 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp) * nfs_client struct */ clp->cl_cons_state = NFS_CS_SESSION_INITING; + init_completion(&session->complete); tbl = &session->fc_slot_table; spin_lock_init(&tbl->slot_tbl_lock); |