Re: [PATCH] target: Allow for target_submit_cmd() returning errors
On Wed, 2012-07-18 at 11:10 +0200, Sebastian Andrzej Siewior wrote:
> On 07/18/2012 02:05 AM, Nicholas A. Bellinger wrote:
> >> index 02ace18..9ddf315 100644
> >> --- a/drivers/usb/gadget/tcm_usb_gadget.c
> >> +++ b/drivers/usb/gadget/tcm_usb_gadget.c
> >> @@ -1060,7 +1060,10 @@ static void usbg_cmd_work(struct work_struct *work)
> >>tpg = cmd->fu->tpg;
> >>tv_nexus = tpg->tpg_nexus;
> >>dir = get_cmd_dir(cmd->cmd_buf);
> >> - if (dir< 0) {
> >> + if (dir< 0 ||
> >> + target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> >> +cmd->cmd_buf, cmd->sense_iu.sense,
> >> cmd->unpacked_lun,
> >> +0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE))
> >> {
> >>transport_init_se_cmd(se_cmd,
> >>tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
> >>tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
> >> @@ -1069,12 +1072,7 @@ static void usbg_cmd_work(struct work_struct *work)
> >>transport_send_check_condition_and_sense(se_cmd,
> >>TCM_UNSUPPORTED_SCSI_OPCODE, 1);
> >>usbg_cleanup_cmd(cmd);
> >> - return;
> >>}
> >> -
> >> - target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> >> - cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
> >> - 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE);
> >> }
> >>
> >> static int usbg_submit_command(struct f_uas *fu,
> >
> > Looking at this part again target_submit_cmd() has been moved ahead of
> > target_init_se_cmd() in the exception path, which ends up getting called
> > twice during a target_get_sess_cmd() failure..
> >
> > It looks like usbg_cmd_work() + bot_cmd_work() will need some work if
> > they intends to use a non zero failure to signal exception here, without
> > invoking a CHECK_CONDITION and sense. Actually, I'm not even sure
> > sending a CHECK_CONDITION here after the target_submit_cmd() is going to
> > work for other fabrics drivers, but it appears to work with usb-gadget.
> > (Sebastian..?)
>
> For UAS the status/ sense URB is sent right away (without any data) and
> this worked the last time I tested.
, thanks for the re-clarification on this.. ;)
> For BOT things are a little complicated. What I do is to send empty
> data (to fill the data pipe) and send a bad status so the other side
> learns that the transfer failed somehow. The sense information is lost.
> What I should do is to queue this sense data for the next MODE_SENSE
> request which will be coming soon. Right now WinXP repeats a failed
> command thrice if MODE_SENSE returns no error. "This" is on my to-fix
> list…
>
Ok, so I think the special case for usb-gadget where is able to call
transport_send_check_condition_and_sense() should be OK for the single
target_get_sess_cmd() -> target_submit_cmd() failure case..
This is not going to be safe for just about every other fabric AFAICT,
so I think we need a comment here to describe that fact..
> > So for the moment, lets fix the double se_cmd init and make things a
> > little easier to read.. Sebastian, please have a look and double check
> > that the (dir< 0) + target_submit_cmd() failures cases are both going
> > to work as expected whilst sending a CHECK_CONDITION response.
>
> The sense code should only be sent once and
> transport_send_check_condition_and_sense() sets
> SCF_SENT_CHECK_CONDITION and checks for it so doing it twice should not
> do any harm right? But grep does not say when this flag gets removed.
>
Correct. The SCF_SENT_CHECK_CONDITION bit does not get removed ahead of
fabric descriptor release.
--
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] target: Allow for target_submit_cmd() returning errors
On 07/18/2012 02:05 AM, Nicholas A. Bellinger wrote:
index 02ace18..9ddf315 100644
--- a/drivers/usb/gadget/tcm_usb_gadget.c
+++ b/drivers/usb/gadget/tcm_usb_gadget.c
@@ -1060,7 +1060,10 @@ static void usbg_cmd_work(struct work_struct *work)
tpg = cmd->fu->tpg;
tv_nexus = tpg->tpg_nexus;
dir = get_cmd_dir(cmd->cmd_buf);
- if (dir< 0) {
+ if (dir< 0 ||
+ target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
+ cmd->cmd_buf, cmd->sense_iu.sense,
cmd->unpacked_lun,
+ 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE))
{
transport_init_se_cmd(se_cmd,
tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
@@ -1069,12 +1072,7 @@ static void usbg_cmd_work(struct work_struct *work)
transport_send_check_condition_and_sense(se_cmd,
TCM_UNSUPPORTED_SCSI_OPCODE, 1);
usbg_cleanup_cmd(cmd);
- return;
}
-
- target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
- cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
- 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE);
}
static int usbg_submit_command(struct f_uas *fu,
Looking at this part again target_submit_cmd() has been moved ahead of
target_init_se_cmd() in the exception path, which ends up getting called
twice during a target_get_sess_cmd() failure..
It looks like usbg_cmd_work() + bot_cmd_work() will need some work if
they intends to use a non zero failure to signal exception here, without
invoking a CHECK_CONDITION and sense. Actually, I'm not even sure
sending a CHECK_CONDITION here after the target_submit_cmd() is going to
work for other fabrics drivers, but it appears to work with usb-gadget.
(Sebastian..?)
For UAS the status/ sense URB is sent right away (without any data) and
this worked the last time I tested.
For BOT things are a little complicated. What I do is to send empty
data (to fill the data pipe) and send a bad status so the other side
learns that the transfer failed somehow. The sense information is lost.
What I should do is to queue this sense data for the next MODE_SENSE
request which will be coming soon. Right now WinXP repeats a failed
command thrice if MODE_SENSE returns no error. "This" is on my to-fix
list…
So for the moment, lets fix the double se_cmd init and make things a
little easier to read.. Sebastian, please have a look and double check
that the (dir< 0) + target_submit_cmd() failures cases are both going
to work as expected whilst sending a CHECK_CONDITION response.
The sense code should only be sent once and
transport_send_check_condition_and_sense() sets
SCF_SENT_CHECK_CONDITION and checks for it so doing it twice should not
do any harm right? But grep does not say when this flag gets removed.
Thanks!
--nab
Sebastian
--
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] target: Allow for target_submit_cmd() returning errors
On Tue, 2012-07-17 at 23:37 +, Nicholas A. Bellinger wrote:
> From: Roland Dreier
>
> We want it to be possible for target_submit_cmd() to return errors up
> to its fabric module callers. For now just update the prototype to
> return an int, and update all callers to handle non-zero return values
> as an error.
>
> This is immediately useful for tcm_qla2xxx to fix a long-standing active
> I/O session shutdown race, but tcm_fc, usb-gadget, and sbp-target the
> fabric maintainers need to check + ACK that handling a target_submit_cmd()
> failure due to session shutdown does not introduce regressions
>
> (nab: Respin against for-next after initial NACK + update docbook comment)
>
+ trimming CC to USB folks:
> index 02ace18..9ddf315 100644
> --- a/drivers/usb/gadget/tcm_usb_gadget.c
> +++ b/drivers/usb/gadget/tcm_usb_gadget.c
> @@ -1060,7 +1060,10 @@ static void usbg_cmd_work(struct work_struct *work)
> tpg = cmd->fu->tpg;
> tv_nexus = tpg->tpg_nexus;
> dir = get_cmd_dir(cmd->cmd_buf);
> - if (dir < 0) {
> + if (dir < 0 ||
> + target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> + cmd->cmd_buf, cmd->sense_iu.sense,
> cmd->unpacked_lun,
> + 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE))
> {
> transport_init_se_cmd(se_cmd,
> tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
> tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
> @@ -1069,12 +1072,7 @@ static void usbg_cmd_work(struct work_struct *work)
> transport_send_check_condition_and_sense(se_cmd,
> TCM_UNSUPPORTED_SCSI_OPCODE, 1);
> usbg_cleanup_cmd(cmd);
> - return;
> }
> -
> - target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> - cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
> - 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE);
> }
>
> static int usbg_submit_command(struct f_uas *fu,
> @@ -1172,7 +1170,10 @@ static void bot_cmd_work(struct work_struct *work)
> tpg = cmd->fu->tpg;
> tv_nexus = tpg->tpg_nexus;
> dir = get_cmd_dir(cmd->cmd_buf);
> - if (dir < 0) {
> + if (dir < 0 ||
> + target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> + cmd->cmd_buf, cmd->sense_iu.sense,
> cmd->unpacked_lun,
> + cmd->data_len, cmd->prio_attr, dir, 0)) {
> transport_init_se_cmd(se_cmd,
> tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
> tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
> @@ -1181,12 +1182,7 @@ static void bot_cmd_work(struct work_struct *work)
> transport_send_check_condition_and_sense(se_cmd,
> TCM_UNSUPPORTED_SCSI_OPCODE, 1);
> usbg_cleanup_cmd(cmd);
> - return;
> }
> -
> - target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
> - cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
> - cmd->data_len, cmd->prio_attr, dir, 0);
> }
>
Looking at this part again target_submit_cmd() has been moved ahead of
target_init_se_cmd() in the exception path, which ends up getting called
twice during a target_get_sess_cmd() failure..
It looks like usbg_cmd_work() + bot_cmd_work() will need some work if
they intends to use a non zero failure to signal exception here, without
invoking a CHECK_CONDITION and sense. Actually, I'm not even sure
sending a CHECK_CONDITION here after the target_submit_cmd() is going to
work for other fabrics drivers, but it appears to work with usb-gadget.
(Sebastian..?)
So for the moment, lets fix the double se_cmd init and make things a
little easier to read.. Sebastian, please have a look and double check
that the (dir < 0) + target_submit_cmd() failures cases are both going
to work as expected whilst sending a CHECK_CONDITION response.
Thanks!
--nab
diff --git a/drivers/usb/gadget/tcm_usb_gadget.c
b/drivers/usb/gadget/tcm_usb_gadget.c
index 9ddf315..5444866 100644
--- a/drivers/usb/gadget/tcm_usb_gadget.c
+++ b/drivers/usb/gadget/tcm_usb_gadget.c
@@ -1060,19 +1060,25 @@ static void usbg_cmd_work(struct work_struct *work)
tpg = cmd->fu->tpg;
tv_nexus = tpg->tpg_nexus;
dir = get_cmd_dir(cmd->cmd_buf);
- if (dir < 0 ||
- target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
- cmd->cmd_buf, cmd->sense_iu.sense,
cmd->unpacked_lun,
- 0, cmd->prio_attr, dir, TARGET_SCF_UNKNOWN_SIZE))
{
+ if (dir < 0) {
transport_init_se_cmd(se_cmd,
tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
cmd->prio_attr, cmd->sense_iu.sense);
-
-
[PATCH] target: Allow for target_submit_cmd() returning errors
From: Roland Dreier
We want it to be possible for target_submit_cmd() to return errors up
to its fabric module callers. For now just update the prototype to
return an int, and update all callers to handle non-zero return values
as an error.
This is immediately useful for tcm_qla2xxx to fix a long-standing active
I/O session shutdown race, but tcm_fc, usb-gadget, and sbp-target the
fabric maintainers need to check + ACK that handling a target_submit_cmd()
failure due to session shutdown does not introduce regressions
(nab: Respin against for-next after initial NACK + update docbook comment)
Cc: Chad Dupuis
Cc: Arun Easi
Cc: Chris Boot
Cc: Stefan Richter
Cc: Mark Rustad
Cc: Sebastian Andrzej Siewior
Cc: Felipe Balbi
Cc: Andy Grover
Signed-off-by: Roland Dreier
Signed-off-by: Nicholas Bellinger
---
drivers/scsi/qla2xxx/tcm_qla2xxx.c |3 +--
drivers/target/sbp/sbp_target.c|8 +---
drivers/target/target_core_transport.c | 14 +-
drivers/target/tcm_fc/tfc_cmd.c|8 +---
drivers/usb/gadget/tcm_usb_gadget.c| 20
include/target/target_core_fabric.h|2 +-
6 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 65a7ed9..4752f65 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -597,10 +597,9 @@ static int tcm_qla2xxx_handle_cmd(scsi_qla_host_t *vha,
struct qla_tgt_cmd *cmd,
return -EINVAL;
}
- target_submit_cmd(se_cmd, se_sess, cdb, &cmd->sense_buffer[0],
+ return target_submit_cmd(se_cmd, se_sess, cdb, &cmd->sense_buffer[0],
cmd->unpacked_lun, data_length, fcp_task_attr,
data_dir, flags);
- return 0;
}
static void tcm_qla2xxx_handle_data_work(struct work_struct *work)
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index e10e622..39ddba5 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/drivers/target/sbp/sbp_target.c
@@ -1235,9 +1235,11 @@ static void sbp_handle_command(struct sbp_target_request
*req)
pr_debug("sbp_handle_command ORB:0x%llx unpacked_lun:%d data_len:%d
data_dir:%d\n",
req->orb_pointer, unpacked_lun, data_length, data_dir);
- target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
- req->sense_buf, unpacked_lun, data_length,
- MSG_SIMPLE_TAG, data_dir, 0);
+ if (target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
+ req->sense_buf, unpacked_lun, data_length,
+ MSG_SIMPLE_TAG, data_dir, 0))
+ goto err;
+
return;
err:
diff --git a/drivers/target/target_core_transport.c
b/drivers/target/target_core_transport.c
index 14e54b4..7647eca 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1447,10 +1447,14 @@ EXPORT_SYMBOL(transport_handle_cdb_direct);
* @data_dir: DMA data direction
* @flags: flags for command submission from target_sc_flags_tables
*
+ * Returns non zero to signal active I/O shutdown failure. All other
+ * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
+ * but still return zero here.
+ *
* This may only be called from process context, and also currently
* assumes internal allocation of fabric payload buffer by target-core.
**/
-void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
+int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
u32 data_length, int task_attr, int data_dir, int flags)
{
@@ -1478,7 +1482,7 @@ void target_submit_cmd(struct se_cmd *se_cmd, struct
se_session *se_sess,
*/
rc = target_get_sess_cmd(se_sess, se_cmd, (flags &
TARGET_SCF_ACK_KREF));
if (rc)
- return;
+ return rc;
/*
* Signal bidirectional data payloads to target-core
*/
@@ -1491,13 +1495,13 @@ void target_submit_cmd(struct se_cmd *se_cmd, struct
se_session *se_sess,
transport_send_check_condition_and_sense(se_cmd,
se_cmd->scsi_sense_reason, 0);
target_put_sess_cmd(se_sess, se_cmd);
- return;
+ return 0;
}
rc = target_setup_cmd_from_cdb(se_cmd, cdb);
if (rc != 0) {
transport_generic_request_failure(se_cmd);
- return;
+ return 0;
}
/*
@@ -1507,7 +1511,7 @@ void target_submit_cmd(struct se_cmd *se_cmd, struct
se_session *se_sess,
core_alua_check_nonop_delay(se_cmd);
transport_handle_cdb_direct(se_cmd);
- return;
+ return 0;
}
EXPORT_SYMBOL(target_submit_cmd
