From 0d228c0f7f9e3ade147e57682915c55b92448230 Mon Sep 17 00:00:00 2001 From: Abhijeet Joglekar Date: Tue, 21 Apr 2009 16:26:52 -0700 Subject: [SCSI] libfc: Hold disc mutex while processing gpn ft resp 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 Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_disc.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'drivers/scsi/libfc/fc_disc.c') diff --git a/drivers/scsi/libfc/fc_disc.c b/drivers/scsi/libfc/fc_disc.c index e57556ea5b48..44806307f831 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); } /** -- cgit v1.2.2 From b4c6f54632ad664a3d9e7f05e4ea0f1803e32755 Mon Sep 17 00:00:00 2001 From: Abhijeet Joglekar Date: Tue, 21 Apr 2009 16:27:04 -0700 Subject: [SCSI] libfc: Track rogue remote ports Rogue ports are currently not tracked on any list. The only reference to them is through any outstanding exchanges pending on the rogue ports. If the module is removed while a retry is set on a rogue port (say a Plogi retry for instance), this retry is not cancelled because there is no reference to the rogue port in the discovery rports list. Thus the local port can clean itself up, delete the exchange pool, and then the rogue port timeout can fire and try to start up another exchange. This patch tracks the rogue ports in a new list disc->rogue_rports. Creating a new list instead of using the disc->rports list keeps remote port code change to a minimum. 1) Whenever a rogue port is created, it is immediately added to the disc->rogue_rports list. 2) When the rogues port goes to ready, it is removed from the rogue list and the real remote port is added to the disc->rports list 3) The removal of the rogue from the disc->rogue_rports list is done in the context of the fc_rport_work() workQ thread in discovery callback. 4) Real rports are removed from the disc->rports list like before. Lookup is done only in the real rports list. This avoids making large changes to the remote port code. 5) In fc_disc_stop_rports, the rogues list is traversed in addition to the real list to stop the rogue ports and issue logoffs on them. This way, rogue ports get cleaned up when the local port goes away. 6) rogue remote ports are not removed from the list right away, but removed late in fc_rport_work() context, multiple threads can find the same remote port in the list and call rport_logoff(). Rport_logoff() only continues with the logoff if port is not in NONE state, thus preventing multiple logoffs and multiple list deletions. 7) Since the rport is removed from the disc list at a later stage (in the disc callback), incoming frames can find the rport even if rport_logoff() has been called on the rport. When rport_logoff() is called, the rport state is set to NONE, and we are trying to cancel all exchanges and retries on that port. While in this state, if an incoming Plogi/Prli/Logo or other frames match the rport, we should not reply because the rport is in the NONE state. Just drop the frame, since the rport will be deleted soon in the disc callback (fc_rport_work) 8) In fc_disc_single(), remove rport lookup and call to fc_disc_del_target. fc_disc_single() is called from recv_rscn_req() where rport lookup and rport_logoff is already done. Signed-off-by: Abhijeet Joglekar Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_disc.c | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-) (limited to 'drivers/scsi/libfc/fc_disc.c') diff --git a/drivers/scsi/libfc/fc_disc.c b/drivers/scsi/libfc/fc_disc.c index 44806307f831..4c880656990b 100644 --- a/drivers/scsi/libfc/fc_disc.c +++ b/drivers/scsi/libfc/fc_disc.c @@ -113,6 +113,11 @@ void fc_disc_stop_rports(struct fc_disc *disc) lport->tt.rport_logoff(rport); } + list_for_each_entry_safe(rdata, next, &disc->rogue_rports, peers) { + rport = PRIV_TO_RPORT(rdata); + lport->tt.rport_logoff(rport); + } + mutex_unlock(&disc->disc_mutex); } @@ -131,23 +136,32 @@ static void fc_disc_rport_callback(struct fc_lport *lport, { struct fc_rport_libfc_priv *rdata = rport->dd_data; struct fc_disc *disc = &lport->disc; - int found = 0; FC_DEBUG_DISC("Received a %d event for port (%6x)\n", event, rport->port_id); - if (event == RPORT_EV_CREATED) { + switch (event) { + case RPORT_EV_CREATED: if (disc) { - found = 1; mutex_lock(&disc->disc_mutex); list_add_tail(&rdata->peers, &disc->rports); mutex_unlock(&disc->disc_mutex); } + break; + case RPORT_EV_LOGO: + case RPORT_EV_FAILED: + case RPORT_EV_STOP: + mutex_lock(&disc->disc_mutex); + mutex_lock(&rdata->rp_mutex); + if (rdata->trans_state == FC_PORTSTATE_ROGUE) + list_del(&rdata->peers); + mutex_unlock(&rdata->rp_mutex); + mutex_unlock(&disc->disc_mutex); + break; + default: + break; } - if (!found) - FC_DEBUG_DISC("The rport (%6x) is not maintained " - "by the discovery layer\n", rport->port_id); } /** @@ -439,6 +453,7 @@ static int fc_disc_new_target(struct fc_disc *disc, rdata = rport->dd_data; rdata->ops = &fc_disc_rport_ops; rdata->rp_state = RPORT_ST_INIT; + list_add_tail(&rdata->peers, &disc->rogue_rports); lport->tt.rport_login(rport); } } @@ -630,6 +645,8 @@ static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len) rdata = rport->dd_data; rdata->ops = &fc_disc_rport_ops; rdata->local_port = lport; + list_add_tail(&rdata->peers, + &disc->rogue_rports); lport->tt.rport_login(rport); } else FC_DBG("Failed to allocate memory for " @@ -769,7 +786,6 @@ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, static void fc_disc_single(struct fc_disc *disc, struct fc_disc_port *dp) { struct fc_lport *lport; - struct fc_rport *rport; struct fc_rport *new_rport; struct fc_rport_libfc_priv *rdata; @@ -778,15 +794,12 @@ static void fc_disc_single(struct fc_disc *disc, struct fc_disc_port *dp) if (dp->ids.port_id == fc_host_port_id(lport->host)) goto out; - rport = lport->tt.rport_lookup(lport, dp->ids.port_id); - if (rport) - fc_disc_del_target(disc, rport); - new_rport = lport->tt.rport_create(dp); if (new_rport) { rdata = new_rport->dd_data; rdata->ops = &fc_disc_rport_ops; kfree(dp); + list_add_tail(&rdata->peers, &disc->rogue_rports); lport->tt.rport_login(new_rport); } return; @@ -848,6 +861,7 @@ int fc_disc_init(struct fc_lport *lport) INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout); mutex_init(&disc->disc_mutex); INIT_LIST_HEAD(&disc->rports); + INIT_LIST_HEAD(&disc->rogue_rports); disc->lport = lport; disc->delay = FC_DISC_DELAY; -- cgit v1.2.2