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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-07-30 18:28:13 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-09-11 00:31:39 -0700 |
| commit | 8f9b565482c537821588444e09ff732c7d65ed6e (patch) | |
| tree | b411dd3479eb5f3f86e2eb390c1c973e4b31ee12 /drivers/scsi | |
| parent | 13a3cf08fa1e4b3a252f24202d47a556242aea03 (diff) | |
| download | talos-op-linux-8f9b565482c537821588444e09ff732c7d65ed6e.tar.gz talos-op-linux-8f9b565482c537821588444e09ff732c7d65ed6e.zip | |
target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
This patch adds an optional fabric driver provided SGL limit
that target-core will honor as it's own internal I/O maximum
transfer length limit, as exposed by EVPD=0xb0 block limits
parameters.
This is required for handling cases when host I/O transfer
length exceeds the requested EVPD block limits maximum
transfer length. The initial user of this logic is qla2xxx,
so that we can avoid having to reject I/Os from some legacy
FC hosts where EVPD=0xb0 parameters are not honored.
When se_cmd payload length exceeds the provided limit in
target_check_max_data_sg_nents() code, se_cmd->data_length +
se_cmd->prot_length are reset with se_cmd->residual_count
plus underflow bit for outgoing TFO response callbacks.
It also checks for existing CDB level underflow + overflow
and recalculates final residual_count as necessary.
Note this patch currently assumes 1:1 mapping of PAGE_SIZE
per struct scatterlist entry.
Reported-by: Craig Watson <craig.watson@vanguard-rugged.com>
Cc: Craig Watson <craig.watson@vanguard-rugged.com>
Tested-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/qla2xxx/tcm_qla2xxx.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index c621623abeed..edeb3aefa6fe 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -1808,6 +1808,11 @@ static const struct target_core_fabric_ops tcm_qla2xxx_ops = { .module = THIS_MODULE, .name = "qla2xxx", .node_acl_size = sizeof(struct tcm_qla2xxx_nacl), + /* + * XXX: Limit assumes single page per scatter-gather-list entry. + * Current maximum is ~4.9 MB per se_cmd->t_data_sg with PAGE_SIZE=4096 + */ + .max_data_sg_nents = 1200, .get_fabric_name = tcm_qla2xxx_get_fabric_name, .tpg_get_wwn = tcm_qla2xxx_get_fabric_wwn, .tpg_get_tag = tcm_qla2xxx_get_tag, |
