From: Hiroya Nozaki <[email protected]> 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 <[email protected]> Reviewed-by: Liang Zhen <[email protected]> Reviewed-by: Nikitas Angelinas <[email protected]> Reviewed-by: Keith Mannthey <[email protected]> Reviewed-by: Oleg Drokin <[email protected]> Signed-off-by: Peng Tao <[email protected]> Signed-off-by: Andreas Dilger <[email protected]> --- drivers/staging/lustre/lustre/ptlrpc/service.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/staging/lustre/lustre/ptlrpc/service.c b/drivers/staging/lustre/lustre/ptlrpc/service.c index 6871711..87bd638 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); } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
