Re: [PATCH 1/2] tcm_fc: Generate TASK_SET_FULL status for DataIN failures
On Fri, 2014-06-06 at 14:02 -0700, Nicholas A. Bellinger wrote: > The break aborts the DataIN send loop and invokes ft_queue_status() > below in an attempt to send TASK_SET_FULL status. > > If the ft_queue_status() -> lport->tt.seq_send() also fails, then > -ENOMEM will be returned to the target and a delayed re-queue attempt > will be made. I see. > In any event, updating the comment above to be more precise I'm ok with leaving comment as is for now, just to avoid patch re-spin for this after above clarification. Thanks for detailed clarification //Vasu -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] tcm_fc: Generate TASK_SET_FULL status for DataIN failures
On Fri, 2014-06-06 at 13:51 -0700, Vasu Dev wrote: > On Thu, 2014-06-05 at 23:30 +, Nicholas A. Bellinger wrote: > > From: Nicholas Bellinger > > > > This patch changes ft_queue_data_in() to set SAM_STAT_TASK_SET_FULL > > status upon a lport->tt.seq_send() failure, where it will now stop > > sending subsequent DataIN, and immediately attempt to send the > > response with exception status. > > > > Sending a response with SAM_STAT_TASK_SET_FULL status is useful in > > order to signal the initiator that it should try to reduce it's > > current queue_depth, to lower the number of outstanding I/Os on > > the wire. > > > > Also, add a check to skip sending DataIN if TASK_SET_FULL status > > has already been set due to a response lport->tt.seq_send() > > failure, that has asked target-core to requeue a response. > > > > Reported-by: Vasu Dev > > Cc: Vasu Dev > > Cc: Jun Wu > > Signed-off-by: Nicholas Bellinger > > --- > > drivers/target/tcm_fc/tfc_io.c | 14 +- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c > > index e415af3..140659f 100644 > > --- a/drivers/target/tcm_fc/tfc_io.c > > +++ b/drivers/target/tcm_fc/tfc_io.c > > @@ -82,6 +82,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd) > > > > if (cmd->aborted) > > return 0; > > + > > + if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) > > + goto queue_status; > > + > > ep = fc_seq_exch(cmd->seq); > > lport = ep->lp; > > cmd->seq = lport->tt.seq_start_next(cmd->seq); > > @@ -178,14 +182,22 @@ int ft_queue_data_in(struct se_cmd *se_cmd) > >FC_TYPE_FCP, f_ctl, fh_off); > > error = lport->tt.seq_send(lport, seq, fp); > > if (error) { > > - /* XXX For now, initiator will retry */ > > pr_err_ratelimited("%s: Failed to send frame %p, " > > "xid <0x%x>, remaining %zu, " > > "lso_max <0x%x>\n", > > __func__, fp, ep->xid, > > remaining, lport->lso_max); > > + /* > > +* Generate a TASK_SET_FULL status to notify the > > +* initiator to reduce it's queue_depth, ignoring > > +* the rest of the data-in and immediately attempt > > +* to send the response. > > +*/ > > I see above added check will drop rest of the frames but cannot find > notifying to initiator with the TASK_SET_FULL status as in comments > above, may be just the comment needs update otherwise code changes are > fine. > The break aborts the DataIN send loop and invokes ft_queue_status() below in an attempt to send TASK_SET_FULL status. If the ft_queue_status() -> lport->tt.seq_send() also fails, then -ENOMEM will be returned to the target and a delayed re-queue attempt will be made. In any event, updating the comment above to be more precise.. > > + se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; > > + break; > > } > > } > > +queue_status: > > return ft_queue_status(se_cmd); > > } > > > > Reviewed-by: Vasu Dev > Thanks Vasu! --nab -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] tcm_fc: Generate TASK_SET_FULL status for DataIN failures
On Thu, 2014-06-05 at 23:30 +, Nicholas A. Bellinger wrote: > From: Nicholas Bellinger > > This patch changes ft_queue_data_in() to set SAM_STAT_TASK_SET_FULL > status upon a lport->tt.seq_send() failure, where it will now stop > sending subsequent DataIN, and immediately attempt to send the > response with exception status. > > Sending a response with SAM_STAT_TASK_SET_FULL status is useful in > order to signal the initiator that it should try to reduce it's > current queue_depth, to lower the number of outstanding I/Os on > the wire. > > Also, add a check to skip sending DataIN if TASK_SET_FULL status > has already been set due to a response lport->tt.seq_send() > failure, that has asked target-core to requeue a response. > > Reported-by: Vasu Dev > Cc: Vasu Dev > Cc: Jun Wu > Signed-off-by: Nicholas Bellinger > --- > drivers/target/tcm_fc/tfc_io.c | 14 +- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c > index e415af3..140659f 100644 > --- a/drivers/target/tcm_fc/tfc_io.c > +++ b/drivers/target/tcm_fc/tfc_io.c > @@ -82,6 +82,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd) > > if (cmd->aborted) > return 0; > + > + if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) > + goto queue_status; > + > ep = fc_seq_exch(cmd->seq); > lport = ep->lp; > cmd->seq = lport->tt.seq_start_next(cmd->seq); > @@ -178,14 +182,22 @@ int ft_queue_data_in(struct se_cmd *se_cmd) > FC_TYPE_FCP, f_ctl, fh_off); > error = lport->tt.seq_send(lport, seq, fp); > if (error) { > - /* XXX For now, initiator will retry */ > pr_err_ratelimited("%s: Failed to send frame %p, " > "xid <0x%x>, remaining %zu, " > "lso_max <0x%x>\n", > __func__, fp, ep->xid, > remaining, lport->lso_max); > + /* > + * Generate a TASK_SET_FULL status to notify the > + * initiator to reduce it's queue_depth, ignoring > + * the rest of the data-in and immediately attempt > + * to send the response. > + */ I see above added check will drop rest of the frames but cannot find notifying to initiator with the TASK_SET_FULL status as in comments above, may be just the comment needs update otherwise code changes are fine. > + se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; > + break; > } > } > +queue_status: > return ft_queue_status(se_cmd); > } > Reviewed-by: Vasu Dev -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 1/2] tcm_fc: Generate TASK_SET_FULL status for DataIN failures
From: Nicholas Bellinger This patch changes ft_queue_data_in() to set SAM_STAT_TASK_SET_FULL status upon a lport->tt.seq_send() failure, where it will now stop sending subsequent DataIN, and immediately attempt to send the response with exception status. Sending a response with SAM_STAT_TASK_SET_FULL status is useful in order to signal the initiator that it should try to reduce it's current queue_depth, to lower the number of outstanding I/Os on the wire. Also, add a check to skip sending DataIN if TASK_SET_FULL status has already been set due to a response lport->tt.seq_send() failure, that has asked target-core to requeue a response. Reported-by: Vasu Dev Cc: Vasu Dev Cc: Jun Wu Signed-off-by: Nicholas Bellinger --- drivers/target/tcm_fc/tfc_io.c | 14 +- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c index e415af3..140659f 100644 --- a/drivers/target/tcm_fc/tfc_io.c +++ b/drivers/target/tcm_fc/tfc_io.c @@ -82,6 +82,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd) if (cmd->aborted) return 0; + + if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) + goto queue_status; + ep = fc_seq_exch(cmd->seq); lport = ep->lp; cmd->seq = lport->tt.seq_start_next(cmd->seq); @@ -178,14 +182,22 @@ int ft_queue_data_in(struct se_cmd *se_cmd) FC_TYPE_FCP, f_ctl, fh_off); error = lport->tt.seq_send(lport, seq, fp); if (error) { - /* XXX For now, initiator will retry */ pr_err_ratelimited("%s: Failed to send frame %p, " "xid <0x%x>, remaining %zu, " "lso_max <0x%x>\n", __func__, fp, ep->xid, remaining, lport->lso_max); + /* +* Generate a TASK_SET_FULL status to notify the +* initiator to reduce it's queue_depth, ignoring +* the rest of the data-in and immediately attempt +* to send the response. +*/ + se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; + break; } } +queue_status: return ft_queue_status(se_cmd); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html