| Message ID | 20250210140333.3899021-1-yebin@huaweicloud.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scsi: core: clear driver private data when retry request | expand |
On 2/10/25 6:03 AM, Ye Bin wrote: > From: Ye Bin <yebin10@huawei.com> > > After commit 1bad6c4a57ef > ("scsi: zero per-cmd private driver data for each MQ I/O"), > xen-scsifront/virtio_scsi/snic driver remove code that zeroes > driver-private command data. If request do retry will lead to > driver-private command data remains. Before commit 464a00c9e0ad > ("scsi: core: Kill DRIVER_SENSE") if virtio_scsi do capacity > expansion, first request may return UA then request will do retry, > as driver-private command data remains, request will return UA > again. As a result, the request keeps retrying, and the request > times out and fails. > So zeroes driver-private command data when request do retry. > > Fixes: f7de50da1479 ("scsi: xen-scsifront: Remove code that zeroes driver-private command data") > Fixes: c2bb87318baa ("scsi: virtio_scsi: Remove code that zeroes driver-private command data") > Fixes: c3006a926468 ("scsi: snic: Remove code that zeroes driver-private command data") > Signed-off-by: Ye Bin <yebin10@huawei.com> > --- > drivers/scsi/scsi_lib.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index be0890e4e706..5b0c109c89bb 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1645,6 +1645,17 @@ static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) > sizeof(struct scatterlist); > } > > +static inline void scsi_clear_lld_private_data(struct scsi_cmnd *cmd, > + struct Scsi_Host *shost) > +{ > + /* > + * Only clear the driver-private command data if the LLD does not supply > + * a function to initialize that data. > + */ > + if (!shost->hostt->init_cmd_priv && shost->hostt->cmd_size) > + memset(cmd + 1, 0, shost->hostt->cmd_size); > +} > + > static blk_status_t scsi_prepare_cmd(struct request *req) > { > struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); > @@ -1669,12 +1680,7 @@ static blk_status_t scsi_prepare_cmd(struct request *req) > if (in_flight) > __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); > > - /* > - * Only clear the driver-private command data if the LLD does not supply > - * a function to initialize that data. > - */ > - if (!shost->hostt->init_cmd_priv) > - memset(cmd + 1, 0, shost->hostt->cmd_size); > + scsi_clear_lld_private_data(cmd, shost); > > cmd->prot_op = SCSI_PROT_NORMAL; > if (blk_rq_bytes(req)) > @@ -1848,6 +1854,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, > goto out_dec_host_busy; > req->rq_flags |= RQF_DONTPREP; > } else { > + scsi_clear_lld_private_data(cmd, shost); > clear_bit(SCMD_STATE_COMPLETE, &cmd->state); > } Thanks for the detailed analysis. Has the following (untested) simpler alternative been considered? diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index d776f13cd160..6ee2903b4adb 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1664,13 +1664,6 @@ static blk_status_t scsi_prepare_cmd(struct request *req) if (in_flight) __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); - /* - * Only clear the driver-private command data if the LLD does not supply - * a function to initialize that data. - */ - if (!shost->hostt->init_cmd_priv) - memset(cmd + 1, 0, shost->hostt->cmd_size); - cmd->prot_op = SCSI_PROT_NORMAL; if (blk_rq_bytes(req)) cmd->sc_data_direction = rq_dma_dir(req); @@ -1837,6 +1830,13 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, if (!scsi_host_queue_ready(q, shost, sdev, cmd)) goto out_dec_target_busy; + /* + * Only clear the driver-private command data if the LLD does not supply + * a function to initialize that data. + */ + if (!shost->hostt->init_cmd_priv && shost->hostt->cmd_size) + memset(scsi_cmd_priv(cmd), 0, shost->hostt->cmd_size); + if (!(req->rq_flags & RQF_DONTPREP)) { ret = scsi_prepare_cmd(req); if (ret != BLK_STS_OK)
On 2025/2/12 1:24, Bart Van Assche wrote: > On 2/10/25 6:03 AM, Ye Bin wrote: >> From: Ye Bin <yebin10@huawei.com> >> >> After commit 1bad6c4a57ef >> ("scsi: zero per-cmd private driver data for each MQ I/O"), >> xen-scsifront/virtio_scsi/snic driver remove code that zeroes >> driver-private command data. If request do retry will lead to >> driver-private command data remains. Before commit 464a00c9e0ad >> ("scsi: core: Kill DRIVER_SENSE") if virtio_scsi do capacity >> expansion, first request may return UA then request will do retry, >> as driver-private command data remains, request will return UA >> again. As a result, the request keeps retrying, and the request >> times out and fails. >> So zeroes driver-private command data when request do retry. >> >> Fixes: f7de50da1479 ("scsi: xen-scsifront: Remove code that zeroes >> driver-private command data") >> Fixes: c2bb87318baa ("scsi: virtio_scsi: Remove code that zeroes >> driver-private command data") >> Fixes: c3006a926468 ("scsi: snic: Remove code that zeroes >> driver-private command data") >> Signed-off-by: Ye Bin <yebin10@huawei.com> >> --- >> drivers/scsi/scsi_lib.c | 19 +++++++++++++------ >> 1 file changed, 13 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c >> index be0890e4e706..5b0c109c89bb 100644 >> --- a/drivers/scsi/scsi_lib.c >> +++ b/drivers/scsi/scsi_lib.c >> @@ -1645,6 +1645,17 @@ static unsigned int >> scsi_mq_inline_sgl_size(struct Scsi_Host *shost) >> sizeof(struct scatterlist); >> } >> +static inline void scsi_clear_lld_private_data(struct scsi_cmnd *cmd, >> + struct Scsi_Host *shost) >> +{ >> + /* >> + * Only clear the driver-private command data if the LLD does not >> supply >> + * a function to initialize that data. >> + */ >> + if (!shost->hostt->init_cmd_priv && shost->hostt->cmd_size) >> + memset(cmd + 1, 0, shost->hostt->cmd_size); >> +} >> + >> static blk_status_t scsi_prepare_cmd(struct request *req) >> { >> struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); >> @@ -1669,12 +1680,7 @@ static blk_status_t scsi_prepare_cmd(struct >> request *req) >> if (in_flight) >> __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); >> - /* >> - * Only clear the driver-private command data if the LLD does not >> supply >> - * a function to initialize that data. >> - */ >> - if (!shost->hostt->init_cmd_priv) >> - memset(cmd + 1, 0, shost->hostt->cmd_size); >> + scsi_clear_lld_private_data(cmd, shost); >> cmd->prot_op = SCSI_PROT_NORMAL; >> if (blk_rq_bytes(req)) >> @@ -1848,6 +1854,7 @@ static blk_status_t scsi_queue_rq(struct >> blk_mq_hw_ctx *hctx, >> goto out_dec_host_busy; >> req->rq_flags |= RQF_DONTPREP; >> } else { >> + scsi_clear_lld_private_data(cmd, shost); >> clear_bit(SCMD_STATE_COMPLETE, &cmd->state); >> } > > Thanks for the detailed analysis. Has the following (untested) simpler > alternative been considered? > Thank you for your reply. I've considered your modification plan, but I think it's a little hard to understand and the code feels a little loose. Of course, it's just my own idea. > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index d776f13cd160..6ee2903b4adb 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1664,13 +1664,6 @@ static blk_status_t scsi_prepare_cmd(struct > request *req) > if (in_flight) > __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); > > - /* > - * Only clear the driver-private command data if the LLD does not > supply > - * a function to initialize that data. > - */ > - if (!shost->hostt->init_cmd_priv) > - memset(cmd + 1, 0, shost->hostt->cmd_size); > - > cmd->prot_op = SCSI_PROT_NORMAL; > if (blk_rq_bytes(req)) > cmd->sc_data_direction = rq_dma_dir(req); > @@ -1837,6 +1830,13 @@ static blk_status_t scsi_queue_rq(struct > blk_mq_hw_ctx *hctx, > if (!scsi_host_queue_ready(q, shost, sdev, cmd)) > goto out_dec_target_busy; > > + /* > + * Only clear the driver-private command data if the LLD does not > supply > + * a function to initialize that data. > + */ > + if (!shost->hostt->init_cmd_priv && shost->hostt->cmd_size) > + memset(scsi_cmd_priv(cmd), 0, shost->hostt->cmd_size); > + > if (!(req->rq_flags & RQF_DONTPREP)) { > ret = scsi_prepare_cmd(req); > if (ret != BLK_STS_OK) > >
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index be0890e4e706..5b0c109c89bb 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1645,6 +1645,17 @@ static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) sizeof(struct scatterlist); } +static inline void scsi_clear_lld_private_data(struct scsi_cmnd *cmd, + struct Scsi_Host *shost) +{ + /* + * Only clear the driver-private command data if the LLD does not supply + * a function to initialize that data. + */ + if (!shost->hostt->init_cmd_priv && shost->hostt->cmd_size) + memset(cmd + 1, 0, shost->hostt->cmd_size); +} + static blk_status_t scsi_prepare_cmd(struct request *req) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); @@ -1669,12 +1680,7 @@ static blk_status_t scsi_prepare_cmd(struct request *req) if (in_flight) __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); - /* - * Only clear the driver-private command data if the LLD does not supply - * a function to initialize that data. - */ - if (!shost->hostt->init_cmd_priv) - memset(cmd + 1, 0, shost->hostt->cmd_size); + scsi_clear_lld_private_data(cmd, shost); cmd->prot_op = SCSI_PROT_NORMAL; if (blk_rq_bytes(req)) @@ -1848,6 +1854,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, goto out_dec_host_busy; req->rq_flags |= RQF_DONTPREP; } else { + scsi_clear_lld_private_data(cmd, shost); clear_bit(SCMD_STATE_COMPLETE, &cmd->state); }