On 8/12/24 3:22 PM, Martin Wilck wrote: > On Tue, 2024-07-30 at 12:51 -0500, Brian King wrote: >> There are some scenarios that can occur, such as performing an >> upgrade of the virtual I/O server, where the supported max transfer >> of the backing device for an ibmvfc HBA can change. If the max >> transfer of the backing device decreases, this can cause issues with >> previously discovered LUNs. This patch accomplishes two things. >> First, it changes the default ibmvfc max transfer value to 1MB. >> This is generally supported by all backing devices, which should >> mitigate this issue out of the box. Secondly, it adds a module >> parameter, enabling a user to increase the max transfer value to >> values that are larger than 1MB, as long as they have configured >> these larger values on the virtual I/O server as well. >> >> Signed-off-by: Brian King <brking@xxxxxxxxxxxxx> >> --- >> drivers/scsi/ibmvscsi/ibmvfc.c | 10 +++++++--- >> drivers/scsi/ibmvscsi/ibmvfc.h | 2 +- >> 2 files changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c >> b/drivers/scsi/ibmvscsi/ibmvfc.c >> index a3d1013c8307..611901562e06 100644 >> --- a/drivers/scsi/ibmvscsi/ibmvfc.c >> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c >> @@ -37,6 +37,7 @@ static unsigned int default_timeout = >> IBMVFC_DEFAULT_TIMEOUT; >> static u64 max_lun = IBMVFC_MAX_LUN; >> static unsigned int max_targets = IBMVFC_MAX_TARGETS; >> static unsigned int max_requests = IBMVFC_MAX_REQUESTS_DEFAULT; >> +static unsigned int max_sectors = IBMVFC_MAX_SECTORS; >> static u16 scsi_qdepth = IBMVFC_SCSI_QDEPTH; >> static unsigned int disc_threads = IBMVFC_MAX_DISC_THREADS; >> static unsigned int ibmvfc_debug = IBMVFC_DEBUG; >> @@ -83,6 +84,9 @@ MODULE_PARM_DESC(default_timeout, >> module_param_named(max_requests, max_requests, uint, S_IRUGO); >> MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter. " >> "[Default=" >> __stringify(IBMVFC_MAX_REQUESTS_DEFAULT) "]"); >> +module_param_named(max_sectors, max_sectors, uint, S_IRUGO); >> +MODULE_PARM_DESC(max_sectors, "Maximum sectors for this adapter. " >> + "[Default=" __stringify(IBMVFC_MAX_SECTORS) "]"); >> module_param_named(scsi_qdepth, scsi_qdepth, ushort, S_IRUGO); >> MODULE_PARM_DESC(scsi_qdepth, "Maximum scsi command depth per >> adapter queue. " >> "[Default=" __stringify(IBMVFC_SCSI_QDEPTH) "]"); >> @@ -1494,7 +1498,7 @@ static void ibmvfc_set_login_info(struct >> ibmvfc_host *vhost) >> memset(login_info, 0, sizeof(*login_info)); >> >> login_info->ostype = cpu_to_be32(IBMVFC_OS_LINUX); >> - login_info->max_dma_len = cpu_to_be64(IBMVFC_MAX_SECTORS << >> 9); >> + login_info->max_dma_len = cpu_to_be64(max_sectors << 9); >> login_info->max_payload = cpu_to_be32(sizeof(struct >> ibmvfc_fcp_cmd_iu)); >> login_info->max_response = cpu_to_be32(sizeof(struct >> ibmvfc_fcp_rsp)); >> login_info->partition_num = cpu_to_be32(vhost- >>> partition_number); >> @@ -5230,7 +5234,7 @@ static void ibmvfc_npiv_login_done(struct >> ibmvfc_event *evt) >> } >> >> vhost->logged_in = 1; >> - npiv_max_sectors = min((uint)(be64_to_cpu(rsp->max_dma_len) >>>> 9), IBMVFC_MAX_SECTORS); >> + npiv_max_sectors = min((uint)(be64_to_cpu(rsp->max_dma_len) >>>> 9), max_sectors); >> dev_info(vhost->dev, "Host partition: %s, device: %s %s %s >> max sectors %u\n", >> rsp->partition_name, rsp->device_name, rsp- >>> port_loc_code, >> rsp->drc_name, npiv_max_sectors); >> @@ -6329,7 +6333,7 @@ static int ibmvfc_probe(struct vio_dev *vdev, >> const struct vio_device_id *id) >> shost->can_queue = scsi_qdepth; >> shost->max_lun = max_lun; >> shost->max_id = max_targets; >> - shost->max_sectors = IBMVFC_MAX_SECTORS; >> + shost->max_sectors = max_sectors; > > Would it make sense to check whether the user-provided max_sectors > value is within some reasonable limits? Agreed. I'll follow up with an updated version. Thanks, Brian -- Brian King Power Linux I/O IBM Linux Technology Center
