[PATCH 1/4] nvme-fabrics: add command id quirk for fabrics controllers

[Max Gurtovoy]

Commit a2941f6aa71a ("nvme: add command id quirk for apple controllers")
introduced a quirk for apple controllers that were affected by adding
the new generation bit inside the command id. Add this quirk for fabrics
controllers as well, since some fabrics implementations also use command
id as an index in their logic. This quirk will be disabled by default
and can be enabled per connection.

For example (with a suitable NVMe-cli version):
nvme connect -t <transport> -n <nqn> -a <addr> -s <sid> --skip-cid-gen
or
nvme connect -t <transport> -n <nqn> -a <addr> -s <sid> -p

As was mentioned for the apple controllers commit, the driver will not
have the ability to detect bad completions when this quirk is used, but
we weren't previously checking this anyway.

Signed-off-by: Max Gurtovoy <mgurtovoy at nvidia.com>
---
 drivers/nvme/host/fabrics.c | 7 ++++++-
 drivers/nvme/host/fabrics.h | 2 ++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index c5a2b71c5268..c8ec8ae2266a 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -549,6 +549,7 @@ static const match_table_t opt_tokens = {
 	{ NVMF_OPT_TOS,			"tos=%d"		},
 	{ NVMF_OPT_FAIL_FAST_TMO,	"fast_io_fail_tmo=%d"	},
 	{ NVMF_OPT_DISCOVERY,		"discovery"		},
+	{ NVMF_OPT_SKIP_CID_GEN,	"skip_cid_gen"		},
 	{ NVMF_OPT_ERR,			NULL			}
 };
 
@@ -827,6 +828,9 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 		case NVMF_OPT_DISCOVERY:
 			opts->discovery_nqn = true;
 			break;
+		case NVMF_OPT_SKIP_CID_GEN:
+			opts->skip_cid_gen = true;
+			break;
 		default:
 			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
 				p);
@@ -954,7 +958,8 @@ EXPORT_SYMBOL_GPL(nvmf_free_options);
 				 NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
 				 NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
 				 NVMF_OPT_DISABLE_SQFLOW | NVMF_OPT_DISCOVERY |\
-				 NVMF_OPT_FAIL_FAST_TMO)
+				 NVMF_OPT_FAIL_FAST_TMO |\
+				 NVMF_OPT_SKIP_CID_GEN)
 
 static struct nvme_ctrl *
 nvmf_create_ctrl(struct device *dev, const char *buf)
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index c3203ff1c654..eefb2d1d477e 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -68,6 +68,7 @@ enum {
 	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
 	NVMF_OPT_HOST_IFACE	= 1 << 21,
 	NVMF_OPT_DISCOVERY	= 1 << 22,
+	NVMF_OPT_SKIP_CID_GEN	= 1 << 23,
 };
 
 /**
@@ -128,6 +129,7 @@ struct nvmf_ctrl_options {
 	unsigned int		nr_poll_queues;
 	int			tos;
 	int			fast_io_fail_tmo;
+	bool			skip_cid_gen;
 };
 
 /*
-- 
2.18.1