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 | |
parent | 05f0d2364726c92f6b870db654967088349379fe (diff) |
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')
-rw-r--r-- | fs/nfs/nfs4_fs.h | 1 | ||||
-rw-r--r-- | fs/nfs/nfs4proc.c | 26 | ||||
-rw-r--r-- | fs/nfs/nfs4state.c | 15 |
3 files changed, 33 insertions, 9 deletions
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index e9ecd6bf9257..5c7740178a08 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h | |||
@@ -45,6 +45,7 @@ enum nfs4_client_state { | |||
45 | NFS4CLNT_RECLAIM_NOGRACE, | 45 | NFS4CLNT_RECLAIM_NOGRACE, |
46 | NFS4CLNT_DELEGRETURN, | 46 | NFS4CLNT_DELEGRETURN, |
47 | NFS4CLNT_SESSION_RESET, | 47 | NFS4CLNT_SESSION_RESET, |
48 | NFS4CLNT_SESSION_DRAINING, | ||
48 | }; | 49 | }; |
49 | 50 | ||
50 | /* | 51 | /* |
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index fb62919f7f2c..c1bc9cad5e85 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, | |||
361 | } | 361 | } |
362 | nfs4_free_slot(tbl, res->sr_slotid); | 362 | nfs4_free_slot(tbl, res->sr_slotid); |
363 | res->sr_slotid = NFS4_MAX_SLOT_TABLE; | 363 | res->sr_slotid = NFS4_MAX_SLOT_TABLE; |
364 | |||
365 | /* Signal state manager thread if session is drained */ | ||
366 | if (test_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) { | ||
367 | spin_lock(&tbl->slot_tbl_lock); | ||
368 | if (tbl->highest_used_slotid == -1) { | ||
369 | dprintk("%s COMPLETE: Session Drained\n", __func__); | ||
370 | complete(&clp->cl_session->complete); | ||
371 | } | ||
372 | spin_unlock(&tbl->slot_tbl_lock); | ||
373 | } | ||
364 | } | 374 | } |
365 | 375 | ||
366 | static void nfs41_sequence_done(struct nfs_client *clp, | 376 | static void nfs41_sequence_done(struct nfs_client *clp, |
@@ -457,15 +467,11 @@ static int nfs41_setup_sequence(struct nfs4_session *session, | |||
457 | 467 | ||
458 | spin_lock(&tbl->slot_tbl_lock); | 468 | spin_lock(&tbl->slot_tbl_lock); |
459 | if (test_bit(NFS4CLNT_SESSION_RESET, &session->clp->cl_state)) { | 469 | if (test_bit(NFS4CLNT_SESSION_RESET, &session->clp->cl_state)) { |
460 | if (tbl->highest_used_slotid != -1) { | 470 | /* |
461 | rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); | 471 | * The state manager will wait until the slot table is empty. |
462 | spin_unlock(&tbl->slot_tbl_lock); | 472 | * Schedule the reset thread |
463 | dprintk("<-- %s: Session reset: draining\n", __func__); | 473 | */ |
464 | return -EAGAIN; | 474 | dprintk("%s Schedule Session Reset\n", __func__); |
465 | } | ||
466 | |||
467 | /* The slot table is empty; start the reset thread */ | ||
468 | dprintk("%s Session Reset\n", __func__); | ||
469 | rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); | 475 | rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); |
470 | nfs4_schedule_state_manager(session->clp); | 476 | nfs4_schedule_state_manager(session->clp); |
471 | spin_unlock(&tbl->slot_tbl_lock); | 477 | spin_unlock(&tbl->slot_tbl_lock); |
@@ -4506,6 +4512,7 @@ static int nfs4_reset_slot_tables(struct nfs4_session *session) | |||
4506 | 1); | 4512 | 1); |
4507 | if (status) | 4513 | if (status) |
4508 | return status; | 4514 | return status; |
4515 | init_completion(&session->complete); | ||
4509 | 4516 | ||
4510 | status = nfs4_reset_slot_table(&session->bc_slot_table, | 4517 | status = nfs4_reset_slot_table(&session->bc_slot_table, |
4511 | session->bc_attrs.max_reqs, | 4518 | session->bc_attrs.max_reqs, |
@@ -4608,6 +4615,7 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp) | |||
4608 | * nfs_client struct | 4615 | * nfs_client struct |
4609 | */ | 4616 | */ |
4610 | clp->cl_cons_state = NFS_CS_SESSION_INITING; | 4617 | clp->cl_cons_state = NFS_CS_SESSION_INITING; |
4618 | init_completion(&session->complete); | ||
4611 | 4619 | ||
4612 | tbl = &session->fc_slot_table; | 4620 | tbl = &session->fc_slot_table; |
4613 | spin_lock_init(&tbl->slot_tbl_lock); | 4621 | spin_lock_init(&tbl->slot_tbl_lock); |
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index f56f6be5e314..3c1433598b60 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c | |||
@@ -1181,8 +1181,23 @@ static void nfs4_session_recovery_handle_error(struct nfs_client *clp, int err) | |||
1181 | 1181 | ||
1182 | static int nfs4_reset_session(struct nfs_client *clp) | 1182 | static int nfs4_reset_session(struct nfs_client *clp) |
1183 | { | 1183 | { |
1184 | struct nfs4_session *ses = clp->cl_session; | ||
1185 | struct nfs4_slot_table *tbl = &ses->fc_slot_table; | ||
1184 | int status; | 1186 | int status; |
1185 | 1187 | ||
1188 | INIT_COMPLETION(ses->complete); | ||
1189 | spin_lock(&tbl->slot_tbl_lock); | ||
1190 | if (tbl->highest_used_slotid != -1) { | ||
1191 | set_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state); | ||
1192 | spin_unlock(&tbl->slot_tbl_lock); | ||
1193 | status = wait_for_completion_interruptible(&ses->complete); | ||
1194 | clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state); | ||
1195 | if (status) /* -ERESTARTSYS */ | ||
1196 | goto out; | ||
1197 | } else { | ||
1198 | spin_unlock(&tbl->slot_tbl_lock); | ||
1199 | } | ||
1200 | |||
1186 | status = nfs4_proc_destroy_session(clp->cl_session); | 1201 | status = nfs4_proc_destroy_session(clp->cl_session); |
1187 | if (status && status != -NFS4ERR_BADSESSION && | 1202 | if (status && status != -NFS4ERR_BADSESSION && |
1188 | status != -NFS4ERR_DEADSESSION) { | 1203 | status != -NFS4ERR_DEADSESSION) { |