projects / ipfire-2.x.git / blame
| Commit | Line | Data |
|---|---|---|
| 2cb7cef9 BS |
1 | From: Gerald Schaefer <geraldsc@de.ibm.com> |
| 2 | Subject: zfcp: Use only single SBAL commands from recovery | |
| 3 | References: bnc#518291,LTC#54462 | |
| 4 | ||
| 5 | Symptom: Issuing an ELS request might not detect a stalled | |
| 6 | outbound queue | |
| 7 | Problem: zfcp uses chained SBALs for ELS requests leading to the | |
| 8 | situation that the ELS request gets one free SBAL, but | |
| 9 | not the following ones. In this situation the ELS request | |
| 10 | fails but does not trigger the error handling for the | |
| 11 | stalled queue. | |
| 12 | Solution: Use unchained SBALs where possible, especially for | |
| 13 | commands from the erp. This guarantees that each erp | |
| 14 | command will get the required SBAL or trigger queue | |
| 15 | recovery. | |
| 16 | ||
| 17 | Acked-by: John Jolly <jjolly@suse.de> | |
| 18 | --- | |
| 19 | drivers/s390/scsi/zfcp_fsf.c | 33 +++++++++++++++++++++++++-------- | |
| 20 | 1 file changed, 25 insertions(+), 8 deletions(-) | |
| 21 | ||
| 22 | --- a/drivers/s390/scsi/zfcp_fsf.c 2009-07-01 12:26:28.000000000 +0200 | |
| 23 | +++ b/drivers/s390/scsi/zfcp_fsf.c 2009-07-01 12:28:43.000000000 +0200 | |
| 24 | @@ -1012,6 +1012,23 @@ skip_fsfstatus: | |
| 25 | send_ct->handler(send_ct->handler_data); | |
| 26 | } | |
| 27 | ||
| 28 | +static void zfcp_fsf_setup_ct_els_unchained(struct qdio_buffer_element *sbale, | |
| 29 | + struct scatterlist *sg_req, | |
| 30 | + struct scatterlist *sg_resp) | |
| 31 | +{ | |
| 32 | + sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE_READ; | |
| 33 | + sbale[2].addr = sg_virt(sg_req); | |
| 34 | + sbale[2].length = sg_req->length; | |
| 35 | + sbale[3].addr = sg_virt(sg_resp); | |
| 36 | + sbale[3].length = sg_resp->length; | |
| 37 | + sbale[3].flags |= SBAL_FLAGS_LAST_ENTRY; | |
| 38 | +} | |
| 39 | + | |
| 40 | +static int zfcp_fsf_one_sbal(struct scatterlist *sg) | |
| 41 | +{ | |
| 42 | + return sg_is_last(sg) && sg->length <= PAGE_SIZE; | |
| 43 | +} | |
| 44 | + | |
| 45 | static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req, | |
| 46 | struct scatterlist *sg_req, | |
| 47 | struct scatterlist *sg_resp, | |
| 48 | @@ -1022,16 +1039,16 @@ static int zfcp_fsf_setup_ct_els_sbals(s | |
| 49 | int bytes; | |
| 50 | ||
| 51 | if (!(feat & FSF_FEATURE_ELS_CT_CHAINED_SBALS)) { | |
| 52 | - if (sg_req->length > PAGE_SIZE || sg_resp->length > PAGE_SIZE || | |
| 53 | - !sg_is_last(sg_req) || !sg_is_last(sg_resp)) | |
| 54 | + if (!zfcp_fsf_one_sbal(sg_req) || !zfcp_fsf_one_sbal(sg_resp)) | |
| 55 | return -EOPNOTSUPP; | |
| 56 | ||
| 57 | - sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE_READ; | |
| 58 | - sbale[2].addr = sg_virt(sg_req); | |
| 59 | - sbale[2].length = sg_req->length; | |
| 60 | - sbale[3].addr = sg_virt(sg_resp); | |
| 61 | - sbale[3].length = sg_resp->length; | |
| 62 | - sbale[3].flags |= SBAL_FLAGS_LAST_ENTRY; | |
| 63 | + zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp); | |
| 64 | + return 0; | |
| 65 | + } | |
| 66 | + | |
| 67 | + /* use single, unchained SBAL if it can hold the request */ | |
| 68 | + if (zfcp_fsf_one_sbal(sg_req) && zfcp_fsf_one_sbal(sg_resp)) { | |
| 69 | + zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp); | |
| 70 | return 0; | |
| 71 | } | |
| 72 |