From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Love Subject: [PATCH 01/15] libfc: Hold disc mutex while processing gpn ft resp Date: Fri, 03 Apr 2009 14:58:03 -0700 Message-ID: <20090403215803.10856.23623.stgit@fritz> References: <20090403215758.10856.6946.stgit@fritz> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com ([192.55.52.88]:8022 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762686AbZDCV6F (ORCPT ); Fri, 3 Apr 2009 17:58:05 -0400 In-Reply-To: <20090403215758.10856.6946.stgit@fritz> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org From: Abhijeet Joglekar gpn_ft_resp processing currently does not hold the discovery lock. disc_done() thus gets called from gpn_ft_resp or from gpn_ft_parse without the lock held. This then sets disc->pending to zero or calls gpn_ft_req() without disc_lock held. - Hold disc mutex during gpn_ft resp processing - In disc_done, release the disc mutex while calling lport callback Signed-off-by: Abhijeet Joglekar Signed-off-by: Robert Love --- drivers/scsi/libfc/fc_disc.c | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/libfc/fc_disc.c b/drivers/scsi/libfc/fc_disc.c index e57556e..4480630 100644 --- a/drivers/scsi/libfc/fc_disc.c +++ b/drivers/scsi/libfc/fc_disc.c @@ -461,21 +461,29 @@ static void fc_disc_del_target(struct fc_disc *disc, struct fc_rport *rport) /** * fc_disc_done() - Discovery has been completed * @disc: FC discovery context + * Locking Note: This function expects that the disc mutex is locked before + * it is called. The discovery callback is then made with the lock released, + * and the lock is re-taken before returning from this function */ static void fc_disc_done(struct fc_disc *disc) { struct fc_lport *lport = disc->lport; + enum fc_disc_event event; FC_DEBUG_DISC("Discovery complete for port (%6x)\n", fc_host_port_id(lport->host)); - disc->disc_callback(lport, disc->event); + event = disc->event; disc->event = DISC_EV_NONE; if (disc->requested) fc_disc_gpn_ft_req(disc); else disc->pending = 0; + + mutex_unlock(&disc->disc_mutex); + disc->disc_callback(lport, event); + mutex_lock(&disc->disc_mutex); } /** @@ -681,8 +689,8 @@ static void fc_disc_timeout(struct work_struct *work) * @fp: response frame * @lp_arg: Fibre Channel host port instance * - * Locking Note: This function expects that the disc_mutex is locked - * before it is called. + * Locking Note: This function is called without disc mutex held, and + * should do all its processing with the mutex held */ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, void *disc_arg) @@ -695,11 +703,13 @@ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, unsigned int len; int error; + mutex_lock(&disc->disc_mutex); FC_DEBUG_DISC("Received a GPN_FT response on port (%6x)\n", fc_host_port_id(disc->lport->host)); if (IS_ERR(fp)) { fc_disc_error(disc, fp); + mutex_unlock(&disc->disc_mutex); return; } @@ -744,6 +754,8 @@ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, disc->seq_count++; } fc_frame_free(fp); + + mutex_unlock(&disc->disc_mutex); } /**