RDMA/srp: Add parse function for maximum initiator to target IU size

According to SRP specifications 'srp-r16a' and 'srp2r06',
IOControllerProfile attributes for SRP target port include the maximum
initiator to target IU size.

SRP connection daemons, such as srp_daemon, can get the value from the
subnet manager. The SRP connection daemon can pass this value to kernel.

This patch adds a parse function for it.

Upstream commit [1] enables the kernel parameter, 'use_imm_data', by
default. [1] also use (8 * 1024) as the default value for kernel parameter
'max_imm_data'. With those default values, the maximum initiator to target
IU size will be 8260.

In case the SRPT modules, which include the in-tree 'ib_srpt.ko' module,
do not support SRP-2 'immediate data' feature, the default maximum
initiator to target IU size is significantly smaller than 8260. For
'ib_srpt.ko' module, which built from source before [2], the default
maximum initiator to target IU is 2116.

[1] introduces a regression issue for old srp targets with default kernel
parameters, as the connection will be rejected because of a too large
maximum initiator to target IU size.

[1] commit 882981f4a4 ("RDMA/srp: Add support for immediate data")
[2] commit 5dabcd0456 ("RDMA/srpt: Add support for immediate data")

Link: https://lore.kernel.org/r/20190927174352.7800-1-honli@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Honggang Li 2019-09-28 01:43:51 +08:00 committed by Jason Gunthorpe
parent 909624d8db
commit 547ed331bb
3 changed files with 13 additions and 0 deletions

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@ -67,6 +67,8 @@ Description: Interface for making ib_srp connect to a new target.
initiator is allowed to queue per SCSI host. The default
value for this parameter is 62. The lowest supported value
is 2.
* max_it_iu_size, a decimal number specifying the maximum
initiator to target information unit length.
What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev
Date: January 2, 2006

View File

@ -3414,6 +3414,7 @@ enum {
SRP_OPT_IP_SRC = 1 << 15,
SRP_OPT_IP_DEST = 1 << 16,
SRP_OPT_TARGET_CAN_QUEUE= 1 << 17,
SRP_OPT_MAX_IT_IU_SIZE = 1 << 18,
};
static unsigned int srp_opt_mandatory[] = {
@ -3446,6 +3447,7 @@ static const match_table_t srp_opt_tokens = {
{ SRP_OPT_QUEUE_SIZE, "queue_size=%d" },
{ SRP_OPT_IP_SRC, "src=%s" },
{ SRP_OPT_IP_DEST, "dest=%s" },
{ SRP_OPT_MAX_IT_IU_SIZE, "max_it_iu_size=%d" },
{ SRP_OPT_ERR, NULL }
};
@ -3739,6 +3741,14 @@ static int srp_parse_options(struct net *net, const char *buf,
target->tl_retry_count = token;
break;
case SRP_OPT_MAX_IT_IU_SIZE:
if (match_int(args, &token) || token < 0) {
pr_warn("bad maximum initiator to target IU size '%s'\n", p);
goto out;
}
target->max_it_iu_size = token;
break;
default:
pr_warn("unknown parameter or missing value '%s' in target creation request\n",
p);

View File

@ -210,6 +210,7 @@ struct srp_target_port {
u32 ch_count;
u32 lkey;
enum srp_target_state state;
uint32_t max_it_iu_size;
unsigned int cmd_sg_cnt;
unsigned int indirect_size;
bool allow_ext_sg;