diff options
| author | Hiroya Nozaki <nozaki.hiroya@jp.fujitsu.com> | 2013-07-23 00:06:48 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-23 13:35:50 -0700 |
| commit | 5be8e0702619eb3e77ec41c3b8825d0bbdfd8cda (patch) | |
| tree | 9da427838c4d2f1e42becfc7180a42d080bdd538 | |
| parent | a55e0f44cf360a2f466b4599ec107fae4bafae64 (diff) | |
staging/lustre/ptlrpc: Race between start and stop service threads
When ptlrpc_start_thread fails to create a new thread, it will
finalize and free a struct ptlrpc_thread created and used here.
Considering this, it can be a problem when ptlrpc_svcpt_stop_thread
is driven and handles the struct ptlrpc_thread right after or right
before failure of cfs_create_thread. Because this situation let
the both of ptlrpc_start_thread and ptlrpc_svcpt_stop_threads
access the freed ptlrpc_thread and cause OS panic. Or, it may
happen that ptlrpc_svcpt_stop_threads waits forever holding an
already-freed waitq.
This patch adds an error handling into ptlrpc_start_thread to fix
this problem.
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2889
Lustre-change: http://review.whamcloud.com/5552
Signed-off-by: Hiroya Nozaki <nozaki.hiroya@jp.fujitsu.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Nikitas Angelinas <nikitas_angelinas@xyratex.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/lustre/lustre/ptlrpc/service.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/staging/lustre/lustre/ptlrpc/service.c b/drivers/staging/lustre/lustre/ptlrpc/service.c index 687171102319..87bd63858b1c 100644 --- a/drivers/staging/lustre/lustre/ptlrpc/service.c +++ b/drivers/staging/lustre/lustre/ptlrpc/service.c @@ -2765,11 +2765,19 @@ int ptlrpc_start_thread(struct ptlrpc_service_part *svcpt, int wait) CERROR("cannot start thread '%s': rc %d\n", thread->t_name, rc); spin_lock(&svcpt->scp_lock); - list_del(&thread->t_link); --svcpt->scp_nthrs_starting; - spin_unlock(&svcpt->scp_lock); - - OBD_FREE(thread, sizeof(*thread)); + if (thread_is_stopping(thread)) { + /* this ptlrpc_thread is being hanled + * by ptlrpc_svcpt_stop_threads now + */ + thread_add_flags(thread, SVC_STOPPED); + wake_up(&thread->t_ctl_waitq); + spin_unlock(&svcpt->scp_lock); + } else { + list_del(&thread->t_link); + spin_unlock(&svcpt->scp_lock); + OBD_FREE_PTR(thread); + } RETURN(rc); } |